EPA/625/R-00/001

July 2000

National Conference on Tools for

Urban Water Resource

Management and Protection

Proceedings

February 7-10, 2000

Chicago, IL

Technology Transfer and Support Division

National Risk Management Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, OH 45268
Notice

The views expressed in these Proceedings are those of the individual authors and do not necessarily reflect

the views and policies of the U.S. Environmental Protection Agency (EPA). Scientists in EPA’s Office of

Research and Development have prepared the EPA sections, and those sections have been reviewed in

accordance with EPA’s peer and administrative review policies and approved for presentation and publication.
Preface

A wide array of effective water quality management and protection tools has been developed for urban

environments, but implementation is hindered by a shortage of technology transfer opportunities. Held in

Chicago, Illinois on February 8-10,2000, the National Conference on Tools for Urban Water Resource

ManagemenlandProieclionwas designed to facilitate the educational process and transfer state-of-the-art

information to state, regional, and local urban water quality practitioners.

The Chicago Botanic Garden, which is owned by the Forest Preserve District of Cook County and managed

by the Chicago Horticultural Society, was pleased to coordinate the Office of Wastewater Management and

its Region 5 office, as well as the Northeastern Illinois Planning Commission. The conference was conducted

in cooperation with the Water Environment Federation. Over 450 attendees participated, including

representatives from Australia, Brazil, Canada, Chile, New Zealand, and Turkey.

The timing for this conference coincided well with the U.S. Environmental Protection Agency’s release of the

NPDES Storm Water Phase II Final Rule in October 1999. The conference provided participants with

practical, applied information on the most effective tools and technologies for meeting these new NPDES

permit requirements. Program topics were carefully chosen to reflect the Phase II Program’s six priorities:

public education, public involvement, detection and elimination of illicit discharges, construction site runoff

control, post-construction storm water management, and pollution prevention for municipal operations.

Two special pre-conference workshops were held on February 7. Better Site Design and Storm Wafer

Management Techniques for Phase II Communitiesexplored the benefits of alternative urban site design

approaches, as well as new advances in storm water management to protect water resources. The workshop

was led by staff from the Center for Watershed Protection. The second pre-conference workshop,

introduction to Urban TMDLs, examined current and pending requirements for total maximum daily load

(TMDL) programs. Instructors for this workshop were staff from Tetra Tech, Inc. Each of the workshops

attracted over 135 participants.

This Conference Proceedings includes many of the papers presented during the conference. All papers

included were peer reviewed. Additional copies, in either paper or CD-ROM format, are available free of

charge from the U.S. Environmental Protection Agency, telephone 800/490-9198, or visit the web site

chttp://www.epa.aov/ttbnrmrl/>.
Foreword

The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation’s land, air, and

water resources. Under a mandate of national environmental laws, the Agency strives to formulate and

implement actions leading to a compatible balance between human activities and the ability of natural

systems to support and nurture life. To meet this mandate, EPA’s research program is providing data and

technical support for solving environmental problems today and building a science knowledge base necessary

to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or

reduce environmental risks in the future.

The National Risk Management Research Laboratory is the Agency’s center for investigation of technological

and management approaches for reducing risks from threats to human health and the environment. The

focus of the Laboratory’s research program is on methods for the prevention and control of pollution to air,

land, water and subsurface resources; protection of water quality in public water systems; remediation of

contaminated sites and ground water; and prevention and control of indoor air pollution. The goal of this

research effort is to catalyze development and implementation of innovative, cost-effective environmental

technologies; develop scientific and engineering information needed by EPA to support regulatory and policy

decisions; and provide technical support and information transfer to ensure effective implementation of

environmental regulations and strategies.

This publication has been produced as part of the Laboratory’s strategic long-term research plan. It is

published and made available by EPA’s Office of Research and Development to assist the user community

and to link researchers with their clients.

E. Timothy Oppelt, Director

National Risk Management Research Laboratory

iv
Contents

Jordan Cove Urban Watershed National Monitoring Project . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Melville P. Cote, Jr.

U.S. Environmental Protection Agency

Off ice of Ecosystem Protection

Boston, Massachusetts

Dr. John Clausen

University of Connecticut

Bruce Morton

Aqua Solutions, LLC

Paul Stacey

Connecticut Department of Environmental Protection

Stan Zaremba

Connecticut Department of Environmental Protection

Sources of Phosphorous in Stormwater and Street Dirt from Two Urban Residential Basins in

Madison,Wisconsin,1994-95 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

R.J. Waschbusch

U.S. Geological Survey

Middleton, Wisconsin

W.R. Selbig

U.S. Geological Survey

Middleton, Wisconsin

R.T. Bannerman

Wisconsin Department of Natural Resources

Madison, Wisconsin

Using Biological Criteria to Assess and Classify Urban Streams and Develop

Improved Landscape Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Chris 0. Yoder and Robert J. Miltner

Ohio EPA, Division of Surface Water

Ecological Assessment Unit

Groveport, Ohio

Dale White

Ohio EPA, Division of Surface Water

Information Resources Management Section

Columbus. Ohio

GettingPasttheObvious...................................................................... 45

Robbin B. Sotir

Robbin B. Sotir & Associates, Inc.

Marietta, Georgia
Protecting and Enhancing Urban Waters: Using All the Tools Successfully . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Eric H. Livingston

Stormwater/NPS Management Section

Florida Department of Environmental Protection

Tallahassee, Florida

Structures to Enhance Fish Habitat in Urban Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Douglas T. Sovern

URS Greiner Woodward-Clyde

Seattle, Washington

Lessons Learned About Successfully Using Infiltration Practices , . . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . 81

Eric H. Livingston

Stormwater/NPS Management Section

Florida Department of Environmental Protection

Tallahassee, Florida

Potential New Tools for the Use of Tracers to Indicate Sources of Contaminants to

Storm DrainageSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Robert Pitt, Melinda Lalor, Jennifer Harper, and Christy Nix

Department of Civil and Environmental Engineering

The University of Alabama at Birmingham

Birmingham, Alabama

Donald Barbe’

Department of Civil and Environmental Engineering

The University of New Orleans

New Orleans, Louisiana

Elimination of Illicit Connections in Coastal New Hampshire Spurs Cooperation and Controversy . . . . . . . . . . . 110

Natalie Landry and Robert Livingston

New Hampshire Department of Environmental Services

Concord, New Hampshire

Using Collaborative Problem-Solving to Protect North Carolina’s Coastal Resources:

The Experience of the White Oak Advisory Board . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . , . . . . . . . 117

Leon E. Danielson, C. Suzanne Hoover, and Christy A. Perrin

North Carolina State University

Department of Agricultural and Resource Economics

Raleigh, North Carolina

Nancy M. White

North Carolina State University

School of Design

Raleigh, North Carolina

Ron Elmore

North Carolina Department of Transportation

Raleigh, North Carolina

Jennifer L. Platt

Town of Cary

Cat-y, North Carolina

vi
Community Responses to Stormwater Pollution: Case Study Findings with Examples from the Midwest . . . . . . 124

George P. Aponte Clarke

Policy Analyst

Natural Resources Defense Council

New York, New York

Peter H. Lehner

Chief, Environmental Protection Bureau

New York State Attorney General’s Office

New York, New York

Diane M. Cameron

President

Cameron Associates

Kensington, Maryland

Andrew G. Frank

Litigation Associate

Paul, Weiss, Rifkind, Wharton, and Garrison

New York, New York

Integrated Urban Stormwater Master Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Eric Strecker, VP, and Krista Reininga, Sr. Project Engineer

URS Greiner Woodward-Clyde

Portland, Oregon

Conservation Design: Managing Stormwater through Maximizing Preventive Nonstructural Practices . . . . . . . . 147

Wesley R. Horner

Environmental Management Center

Brandywine Conservancy

Chadds Ford, Pennsylvania

Low-Impact Development Design: A New Paradigm for Stormwater Management Mimicking and

Restoring the Natural Hydrologic Regime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . 158

Larry S. Coffman

Associate Director

Department of Environmental Resources

Prince George’s County, Maryland

A National Menu of BMPs for the Phase II NPDES Storm Water Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

James H. Collins

Tetra Tech, Incorporated

Fairfax, Virginia

John A. Kosco, P.E.

USEPAIOffice of Wastewater Management

Washington, D.C.

vii
Determining Urban Stormwater BMP Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Eric Strecker

URS Greiner Woodward Clyde

Portland, Oregon

Marcus M. Quigley

URS Greiner Woodward Clyde

Boston, Massachusetts

Ben R. Urbonas

Urban Drainage and Flood Control District

Denver, Colorado

Texas Nonpoint SourceBOOK is Now On-Line ! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

John Promise, P.E.

Director of Environmental Resources

North Central Texas Council of Governments, and

Chair, Water Resources Management Committee

American Public Works Association

Keith Kennedy

North Central Texas Council of Governments

Robert W. Brashear, Ph.D.

Camp Dresser & McKee, Inc.

A Comparison of the Long-Term Hydrological Impacts of Urban Renewal versus Urban Sprawl . . . . . . . . . . . . . 192

Jon Harbor

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

Bernie Engel

Department of Agricultural and Biological Engineering

Purdue University

West Lafayette, Indiana

Don Jones

Department of Agricultural and Biological Engineering

Purdue University

West Lafayette, Indiana

Shilpam Pandey

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

K.J. Lim

Department of Agricultural and Biological Engineering

Purdue University

West Lafayette, Indiana

Suresh Muthukrishnan

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

Comparative Nutrient Export and Economic Benefits of Conventional and Better Site Design Techniques . . . . . 198

Jennifer Zielinski, Deb Caracao, and Rich Claytor

Center for Watershed Protection

Ellicott City, Maryland

. . . VIII
Predicting Erosion Rates on Construction Sites Using the Universal Soil Loss Equation in

DaneCounty,Wisconsin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

J.D. Balousek

Erosion Control Engineer

Dane County Land Conservation Department (LCD)

A. Roa-Espinosa

Urban Conservationist

Dane County LCD

G.D. Bubenzer

Professor

University of Wisconsin-Madison

Madison, Wisconsin

Public Involvement Programs That Support Water Quality Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Josephine Powell

Wayne County Department of Environment

Detroit, Michigan

Zachare Ball and Karen Reaume

Environmental Consulting & Technology Inc.

Detroit, Michigan

The Water-Wise Gardener Program: Teaching Nutrient Management to Homeowners . . . . . . . . . . . . . . . . . . . . 222

Marc T. Aveni

Virginia Cooperative Extension

Manassas, Virginia

Chicago Wilderness; Toward an Urban Conservation Culture . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

John D. Rogner

U.S. Fish and Wildlife Service

Chicago Field Office

Barrington, Illinois

A Survey of Resident Nutrient Behavior in the Chesapeake Bay Watershed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

Chris Swann

Center for Watershed Protection

Ellicott City, Maryland

Lawn Care and Water Quality: Finding the Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

Jerry Spetzman

Minnesota Department of Agriculture

St. Paul, Minnesota

San Francisco Bay Area’s Pesticide Toxicity Reduction Strategy , . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

Geoff Brosseau

Bay Area Stormwater Management Agencies Association (BASMAA)

Oakland, California

Administering the NPDES Industrial Storm Water Program at the Municipal Level . . . . . . . . . . . . . . . . . . . . . . . . 249

Michael J. Pronold

Bureau of Environmental Services

Portland, Oregon

ix
Lessons Learned From Three Watershed-Sensitive Development Demonstration Projects In

TheGreatLakesBasin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sarah Bennett Nerenberg

The Conservation Fund

Great Lakes Office

Chicago, Illinois

Continuous Deflection Separation (CDS) for Sediment Control in Brevard County, Florida . . . . . . . . . . . . . .

Justin Strynchuk, John Royal, and Gordon England, P.E.

Brevard County Surface Water Improvement

Viera, Florida

Use of Automated Technologies in Watershed Management Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lake County Stormwater Management Commission (SMC)

Libertyville, Illinois

Sediment and Runoff Control on Construction Sites Using Four Application Methods of Polyacrylamide Mix

A. Roa-Espinosa

Urban Conservationist

Dane County Land Conservation Department, and

Assistant Visiting Professor

Biological Systems Engineering

University of Wisconsin-Madison

G.D. Bubenzer

Professor

Biological Systems Engineering

University of Wisconsin-Madison

E.S. Miyashita

Former Project Assistant

Biological Systems Engineering

University of Wisconsin-Madison

. . .

. . .

. . .

256

264

272

278

Construction Site Planning and Management Tools for Water Quality Protection . . . . . . . . . . . . . . . . . . . . . . . . . 284

Thomas Mumley

California Regional Water Quality Control Board

San Francisco Bay Region

Oakland, California

Regulating Sedimentation and Erosion Control into Streams: What Really Works and Why? . . . . . . . . . . . . . . . 291

Seth R. Reice

Department of Biology

University of North Carolina at Chapel Hill

Chapel Hill, North Carolina

JoAnn Carmin

Department of Public Policy

Virginia Polytechnic Institute and State University

Blacksburg, Virginia
Effectiveness in Erosion and Sediment Control: New Initiatives in Indianapolis . . . . . . . . . . . . . . . . . . . . . . . . . , 296

James Hayes and Marcia Mathieu

Marion County Soil and Water Conservation District

Indianapolis, Indiana

Greg Lindsey

Center for Urban Policy and the Environment

School of Public and Environmental Affairs

Indiana University

Indianapolis, Indiana

Using Constructed Wetlands to Reduce Nonpoint Source Pollution in Urban Areas . . . . . . . . . . . . . . . . . . . . . . .

Jon Harbor

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

Susan Tatalovich

FMSM Engineers, Inc.

Columbus, Ohio

Ron Turco

Department of Agronomy

Purdue University

West Lafayette, Indiana

Zac Reicher

Department of Agronomy

Purdue University

West Lafayette, Indiana

Anne Spacie

Department of Forestry and Natural Resources

Purdue University

West Lafayette, Indiana

Vickie Poole

Department of Forestry and Natural Resources

Purdue University

West Lafayette, Indiana

303

Advanced Identification (ADID) Techniques Used to Protect Wetlands and Aquatic Resources in a

RapidlyGrowingCounty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Dennis W. Dreher

Northeastern Illinois Planning Commission

Chicago, Illinois

Local Government Involvement in Mitigation Banking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322

Lisa T. Morales

Wetlands Division

U.S. Environmental Protection Agency

Washington, D.C.

Massachusetts Stormwater Management Policy/Regulations: Development, Implementation, and Refinement . 332

Bethany Eisenberg

Vanasse Hangen Brustlin, Inc.

Watertown, Massachusetts

xi
Implementation of Michigan’s Voluntary Stormwater Permit - A Community Perspective . . . . . . . . . . . . . . . . . . 339

Kelly A. Cave

P.E. Director

Watershed Management Division

Wayne County Department of the Environment

Detroit, Michigan

Dale S. Bryson

Camp Dresser & McKee

Detroit Michigan

Kelly C. Kelly

P.E., Project Engineer

Canton Township, Michigan

Jack D. Bails

Vice-President

Public Sector Consultants

Lansing, Michigan

California’s Model Urban Runoff Program (MURP): Urban Runoff Programs for Small Municipalities . . . . . . . . . 349

Jennifer Hays

Assistant Engineer

Public Works Department

City of Monterey, California

Cy Oggins

Coastal Program Analyst III

California Coastal Commission

Central Coast District

Santa Cruz, California

New Stormwater Treatment BMPs: Determining Acceptability to Local Implementing Agencies . . . . . . . . . . . . . 354

Gary R. Minton

Resource Planning Associates

Seattle, Washington

Paul Bucich

Pierce County Public Works

Tacoma, Washington

Mark Blosser

City of Olympia Public Works

Olympia, Washington

Bill Leif

Snohomish County Surface Water Management

Everett, Washington

Jim Lenhart

Stormwater Management, Inc.

Portland, Oregon

Joseph Simmler

Entrance Engineers

Bellevue, Washington

Steven True

Vortechnics

Federal Way, Washington

xii
ByAnyMeasure............................................................................ 362

Thomas R. Adams, P.E., Vaikko P. Allen, and Andrea Perley

Vottechnics, Inc.

Portland, Maine

Stormceptor Hydrology and Non-Point Source Pollution Removal Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

G. Bryant

Stormceptor Canada

Etobicoke, Ontario, Canada

R. Grant

New England Pipe

Wauregan, Connecticut

D. Weatherbe

Donald G. Weatherbe Associates

Mississauga, Ontario, Canada

V. Berg

Stormceptor Corporation

Rockville, Maryland

NPDES Phase II Cost Estimates . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383

Andrew J. Reese, P.E.

Ogden Environmental and Energy Services, Inc.

Nashville, Tennessee

The Stormwater Utility Concept in the Next Decade (Forget the Millenium) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397

Hector J. Cyre

President

Water Resource Associates, Inc.

Kirkland, Washington

Are Green Lots Worth More Than Brown Lots? An Economic Incentive for Erosion Control on

Residential Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404

Martha Herzog and Jon Harbor

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

Keith McClintock

Geauga Soil and Water Conservation District

Burton, Ohio

John Law

Indiana Department of Natural Resources and

Saint Joseph Soil and Water Conservation District

South Bend, Indiana

Kara Bennett

Department of Statistics

Purdue University

West Lafayette, Indiana

.

XIII
Acknowledgments

The success of the conference and the preparation of this document are due largely to the efforts of the

presenters as well as the following individuals:

Conference Planning Committee

Robert J. Kirschner, Conference Coordinator

Chicago Botanic Garden, Glencoe, IL

Thomas E. Davenport, Project Co-Officer

U.S. Environmental Protection Agency, Region 5, Chicago, IL

John A. Kosco, Project Co-Officer

U.S. Environmental Protection Agency, Washington, DC

Deborah S. Caraco, Center for Watershed Protection, Ellicott City, MD

Martin H. Kelly, Southwest Florida Water Management District, Brooksville, FL

Thomas E. Mumley, California Regional Water Quality Control Board, Oakland, CA

Eric W. Strecker, URS Greiner Woodward Clyde, Portland, OR

Peer Reviewers

Donald Brown, U.S. Environmental Protection Agency, Cincinnati, OH

Deborah S. Caraco and Staff, Center for Watershed Protection, Ellicott City, MD

Alan Everson, U.S. Environmental Protection Agency, Cincinnati, OH

Douglas Grosse, U.S. Environmental Protection Agency, Cincinnati, OH

Larry Shepard, U.S. Environmental Protection Agency, Region 7, Kansas City, KS

Steve Walker, Nebraska Department of Natural Resources, Lincoln, NE

Ruth Wallace and Staff, Missouri Department of Natural Resources, Jefferson City, MO

Jennifer Zielinski and Staff, Center for Watershed Protection, Ellicott City, MD

Technical Editing and Publishing

Scott Minamyer, Jean Dye, and Steve Wilson of the U.S. Environmental Protection Agency, Cincinnati, OH.

xiv
Jordan Cove Urban Watershed National Monitoring Project

Melville P. Cote, Jr.

U.S. Environmental Protection Agency

Office of Ecosystem Protection

Boston, Massachusetts

02114

Dr. John Clausen

University of Connecticut

Bruce Morton

Aqua Solutions, LLC

Paul Stacey and Stan Zaremba

Connecticut Department of Environmental Protection

Introduction

Stormwater runoff from urban and urbanizing areas is widely recognized as a major cause of water pollution in the

United States. The impacts of stormwater runoff are threefold: (1) chemically, contaminants deposited on the land are

carried by runoff and infiltration to surface and groundwater; (2) physically, increases in impervious surfaces raise runoff

rates which, in turn, increase mass pollutant loadings and contribute to erosion and sedimentation; and (3) biologically,

the combined chemical and physical alterations of watershed systems degrade aquatic habitat. Research over the past

20 years consistently shows a strong correlation between the imperviousness of a drainage basin and the health of its

receiving waters, with stream health decreasing with increasing impervious coverage of the watershed.’ The U.S.

Environmental Protection Agency cites urban runoff as the second leading cause of impairment to estuaries and the fourth

leading cause of impairment to lakes.* Increased runoff rates, and the erosion and sedimentation associated with new

development and construction, also are significant sources of pollution. In the United States, there are an estimated

522,000 construction “starts” each year, with construction activities disturbing an estimated 5 million acres of land

annually.3

Connecticut communities, like those in many urbanized states, are confronted with meeting nonpoint source

management needs that often conflict with traditional subdivision regulations and construction standards. The challenge

of meeting publicsafetyand maintenance requirements in an environmentally sensitive manner is not currently being met,

as evidenced by continued water quality impairments associated with new development. Can impervious surfaces be

reduced, and curbing and storm drains be eliminated in a way that will not raise objections from municipal boards and

commissions? Will homeowners accept cluster housing, natural landscaping, and “greener” home and yard maintenance

practices? Most important, will those modifications make a difference in the quality and quantity of nonpoint source runoff

under widespread application? Answering these and related questions is the objective of the Jordan Cove Urban

Watershed National Monitoring Project.

Project Overview

The primary purpose of the Jordan Cove project is to compare differences in runoff quantity and quality emanating from

traditional and “environmentally sensitive” development sites. The 18-acre “Glen Brook Green” subdivision, located in

the southeastern Connecticut town of Waterford, is being constructed and monitored to make this comparison. The

subdivision is split into two distinct “neighborhoods”: one with building lots arranged in a traditional R-20 (half-acre)

1
zoning pattern (Figure 1); the other, cluster housing with a variety of best management practices (BMPs) incorporated

into the design (Figure 2).

Figure 1. Glen Brook Green “Traditional” Neighborhood.

Figure 2. Glen Brook Green “BMP” Neighborhood.
Stormwater runoff from the traditional section is collected by curbs and catch basins, then piped through astormwater

treatment system before entering Nevins Brook, a tributary of Jordan Brook and, ultimately, Jordan Cove and Long Island

Sound. Homeowners will not be subjected to any enhanced environmental education, or restrictions on how they manage

their properties.

The BMP neighborhood will feature grass swales; roof leader “rain gardens;” shared, permeable driveways; small

building “foot-prints;“deed restrictions on increasing impervious surfaces; “low-mow,““no-mow,“andconservation zones;

a narrower, permeable road surface (interlocking concrete pavement); and a vegetated infiltration basin, or bioretention

area, located inside a “tear-drop” cul de sac. Several different driveway surfaces will be utilized, including interlocking

concrete pavement, gravel, concrete tire strips, and permeable asphalt, and monitored for their relative runoff rates.

Homeowners and town road maintenance crews will be encouraged to adopt pollution prevention techniques, including

controlled fertilizer and pesticide application, pet waste management, street sweeping/vacuuming, and reduced use of

deicing agents.

The BMP neighborhood is expected to generate less stormwater runoff and pollution. Monitoring conducted before,

during and after construction will document actual results. The Jordan Cove project team comprises a true public/private

partnership, with researchers and educators from the University of Connecticut; federal, state, and local government

officials; private consulting firms; and the developer.

National Monitoring Program

The Jordan Cove Urban Watershed National Monitoring Project is funded, in part, through the Connecticut

Department of Environmental Protection (CT DEP) by the U.S. Environmental Protection Agency’s (EPA) Section 319

National Monitoring Program (NMP). It is one of 22 such projects nationwide. The Jordan Cove project is the only NMP

project studying the effects of residential subdivision development on runoff quality and quantity, and of BMPs designed

to mitigate those impacts.

The Section 319 NMP was established pursuant to section 319(l) of the federal Clean Water Act (Nonpoint Source

Management Programs - Collection of Information). Section 319(l) states that EPA shall collect information and make

available:

(1) Information concerning the costs and relative efficiencies of best management practices for reducing nonpoint

source pollution.

(2) Data concerning the relationship between water quality and implementation of various management practices

to control nonpoint sources of pollution.

The objectives of the Section 319 NMP are twofold:

(1) To scientifically evaluate the effectiveness of watershed technologies designed to control nonpoint source

pollution.

(2) To improve our understanding of nonpoint source pollution.

To achieve these objectives, the NMP has selected watersheds across the country to be monitored over a 6-to loyear period to evaluate how improved land management and the application of BMPs reduce water pollution. The results

from these projects will be used to assist land use and natural resource managers by providing information on the relative

effectiveness of BMPs to control nonpoint source pollution.

Site Selection

In 1993, nonpoint source program staff from EPA and CT DEP, and a University of Connecticut researcher began

efforts to identify a site at which to conduct a nonpoint source monitoring project under the auspices of the NMP. Initial

3
site selection involved three criteria: (1) an appropriate hydrologic setting, with distinct drainage patterns amenable to

monitoring; (2) a willing land owner or developer who would allow l-1 % years of advance monitoring before beginning

construction; and (3) a municipality willing to adopt innovative site planning and development strategies. Proximity to the

coast was also considered as an important factor because of the need to reduce nonpoint source pollution loads to Long

Island Sound and coastal waters in general.

CT DEP mailed letters soliciting interest to a number of municipalities recognized for either their progressive approach

to land use planning and management, orforexperiencing high development rates. After positive responses from several

municipalities, and numerous field visits, the “Glen Brook Green” site in Waterford was selected in May 1995. The 18-

acre parcel was an active chicken farm, but its owner, who had grown up on the farm, was planning to develop it into a

residential subdivision. The property owner wanted to develop the parcel in an environmentally-sound manner, was

interested in the NMP solicitation, and was willing to be flexible with his construction schedule to facilitate monitoring.

The hydrology of the parcel featured two distinct drainage areas, an ideal setting for the proposed monitoring design.

Poultry houses and several other buildings occupied the area that would become the traditional neighborhood and an old,

partially mined gravel pit dominated the future BMP neighborhood. Soil tests determined that the chicken manure had

not elevated nutrient levels significantly enough to bias the monitoring. The town of Waterford, and its planning officials,

had a reputation as being progressive on land use issues and had served as one of the pilot communities for the

University of Connecticut Cooperative Extension System’s Nonpoint Education for Municipal Officials (NEMO) project.

Because waivers from Water-ford’s subdivision regulations would be needed to build the BMP neighborhood, the town’s

cooperation was critical to the project’s implementation.

Planning

Proceeding from a conceptual design to actual construction required a concentrated effort by the project team working

together toward a common goal. Once an acceptable plan was agreed upon by the project team and committed to paper,

the next step was gaining approval from Water-ford’s conservation, and planning and zoning commissions. As is typical

of New England town governments, both commissions paid close attention to planning decisions at a series of public

meetings at which many development alternatives were reviewed. Volunteer commissioners and professional staff raised

numerous concerns regarding the health, safety and general welfare of the town residents, and the social economic,

environmental, and political viability of the proposed plan. Among their concerns were road widths for emergency access,

road surface integrity for plowing and de-icing, traffic, drainage, sidewalks, parking, maintenance of common areas, and

responsibility should BMPs fail. The rigorous review was enlightening to the project team and commissioners alike. As

the ongoing dialogue between the various parties led to further planning details and innovative solutions to problems,

enthusiasm and support for the project grew.

After a series of public meetings in late 1996 and early 1997, the project was approved by both commissions.

Technical modifications of existing standards were handled in four ways: as waivers, special design/operation controls,

mitigation, or discretionary actions. Table 1 lists each of these categories with associated comments and concerns

expressed by Water-ford’s professional staff and commissions. In the end, it was the willingness of all parties involved

to work in concert, reaching compromises, that allowed this innovative project to advance to the construction phase.

It is a generally accepted axiom that resource-based site planning can help minimize increases in runoff and reduce

the potential for erosion and sedimentation problems typically associated with new development. In this project, goals

identified at the outset are helping to direct the choice of practices and strategies for site development toward those that

will reduce adverse impacts on hydrology and water quality. These goals include: (1) reproducing pre-development

hydrological conditions; (2) confining development and construction activities to the least critical areas; (3) fitting the

development to the terrain; (4) preserving and utilizing the natural drainage system; and (5) creating a desirable living

environment.

4
Table 1. Technical Modifications of Existing Development Standards.

Considerations Traditional Design BMPICluster Design Comments

waivers needed specified road surface materials segmental concrete pavers must be approved by public

(permeable) works; costs more

typical road width = 28 feet, reduced road width to 20 feet must be approved by public

reduced to 24 feet for travel lane works, fire, and police

curbs and storm drains required no curbs; grassed swales turf stone installed to

and sheet flow off road maintain road edge

integrity; costs less

90 ft paved cul-de-sac radius one way cul de sac design to further reduction in width

reduce road width and and less need for snow

turning radius plowing

special design/ planning and zoning standards bioretention “rain gardens” retains roof runoff on-site

operational control

home owner discretion vegetative maintenance reduces fertilizer use; costs

less

home owner discretion pesticide management reduces pesticide use:

costs less

home owner discretion domestic animal reduces pathogen runoff

management

mitigation required road runoff piped to storm sewer need to manage storm

water entering the site from

adjacent public road

creation of 13,400 sq ft wetland at required to mitigate filling

subdivision entrance of 5000 sq ft of wetlands

within subdivision

discretionary R-20 single-family zoning cluster and zero setback allows more open space

actions from lot lines and natural landscaping

open space not contiguous with open space layout compact housing; natural

all lots landscaping

a driveway for each home combined driveways reduces curb cuts and

impervious surface; cost

less

Monitoring Design

This study is utilizing the “paired-watershed” monitoring design, which requires a minimum of two watersheds (control

and treatment) and two periods of study (calibration and treatment). This approach assumes that there is a quantifiable

relationship between paired water quality data for the two watersheds, and that this relationship is valid until a major

change is made in one of the watersheds. It does not require that the quality and quantity of runoff be statistically the

same for the two watersheds, but that the relationship between the paired observations of water quality and quantity

remains the same over time -- except for the influence of the land use changes in the treatment watershed.4

The control watershed accounts for annual and/or seasonal climate variations. During the calibration period, no

changes in land use occur in the watersheds and paired water quality and quantity data are collected to develop a

baseline. The paired data are used to develop regressions for the control and treatment watersheds. The treatment

period begins when changes in land use occur in the treatment watershed. A new regression is developed following the

5
treatment period. Analysis of variance (ANOVA) is used to test the significance of the regressions in each period.

Analysis of covariance (ANCOVA) is used to test the differences between the two regression slopes and intercepts. The

changes between periods are calculated based on a comparison of predicted values, using the calibration regression

equation, and observed values during the treatment period.5

For the Jordan Cove project, the treatment period will occur in two phases: (1) during construction of the traditional

and BMP neighborhoods; and (2) after construction when the BMPs are in effect. The paired-watershed approach is

being used to measure the differences in water quality and quantity between the treatment areas (traditional and BMP

neighborhoods) and the control area (a nearby 1 O-year old subdivision) caused by construction in the two treatment areas

and the application of BMPs in the BMP neighborhood. Stormwater quality and quantity are measured at the outlets of

each of the two treatment neighborhoods, and the control watershed (Figure 3). Water quality is measured by analyzing

weekly flow-weighted composite samples for total suspended solids (TSS), total phosphorus (TP), total Kjeldahl nitrogen

(TKN), ammonia nitrogen (NH,-N), and nitrate+nitrite nitrogen (NO,-N). Grab samples are analyzed for fecal coliform and

BOD,. Monthly analyses are conducted for copper, lead, and zinc.

Figure 3. Existing residential (control) watershed.

The calibration period began in January 1996, to establish a baseline for future comparisons. Since the treatment

period began in May 1998, runoff monitoring has focused on the effects of construction, and on the relative effectiveness

of standard erosion and sediment control practices in the traditional neighborhood. When construction commences in

the BMP neighborhood, the focus will be on the effects of construction and the relative effectiveness of enhanced erosion

and sediment control practices (e.g., phased grading, stockpile seeding, open space vegetation, cross grading, and

detention swales). Post-construction monitoring is scheduled to begin in 2001 and will continue for 3-5 years.

Supplemental monitoring will be conducted on selected BMPs, including different driveway surfaces and enhanced

turf management in the BMP neighborhood, and a “state-of-the-art” stormwater treatment device in the traditional

neighborhood. This information will be used to evaluate the effectiveness of these specific practices.

6
Monitoring Results

During the calibration period, 75 runoff events were sampled for the control watershed and 12 runoff events for the

two treatment watersheds. In the treatment period to date, 21 and 20 events were sampled for each treatment watershed,

respectively. Peak discharge values were obtained for nine paired events in the calibration period and 20 pairs for the

treatment period. The total number of samples analyzed was less than the total number of flow observations because

not all the samples contained a sufficient volume for analysi$.

Sampling results to date, as presented in Table 2, indicate that construction of the traditional neighborhood is causing

significant impacts on runoff quality and quantity, including observed increases in mean weekly flow volume (99%), runoff

frequency (from 16% to 95%), and mean weekly peak discharge (79%).7 The conversion of the watershed’s topography

from a “knoll” to a “bowl,” combined with an increase in impervious surface, appears to have caused a significant change

in hydrologic responses. Concentrations of NO,-N and Pb in runoff also increased. However, increases in the

concentrations of sediment and sediment-associated nutrients, typical of construction sites, did not occur. In fact, TKN

concentrations have declined during construction. It is believed that erosion and sediment controls are responsible for

TSS concentrations remaining constant before and during construction*.

Table 2. Summary of means and percent increases of flow, Q,, nutrient and metal concentrations for the control and traditional watershed in the

calibration and treatment periods.

** P value < 0.01

l ** P value < 0.001

Coinciding with the increases in pollutant concentration and flow, the mass export of NO,-N and Pb increased as well,

as did the mass exports of TP, TSS, Cu, and Zn. These increases appear to be attributable to increased stormwater

7
runoff volumes. The preliminary results from this study suggest that increased runoff, rather than erosion, is the cause

of increased pollutant export from this construction site. Traditionally, erosion and sediment controls and stormwater

management plans focus on the prevention of sediment and, occasionally, peakflow impacts on downstream areas. The

preservation of pre-development hydrologic conditions within the watershed where construction is occurring is typically

ignored.

Excess runoff, which is the driving force behind nonpoint source pollution, will transport pollutants into waterways and

contribute to their degradation. Preliminary monitoring results demonstrate that erosion and sediment controls can reduce

sediment and sediment-associated pollutants in construction site runoff. However, current erosion and sediment control

practices do not address the increase in runoff from development sites. Consequently, these practices fail at reducing

pollutant loads.g

Next Steps

By the end of 2000, this combination of traditional and “green” designs for residential subdivisions should be fully

constructed. Monitoring of stormwater quality and quantity will be conducted for several years after build-out to determine

the overall efficiency of the design. It should demonstrate that careful planning, landscaping, and use of vegetative BMPs

can help protect and enhance the environment, while addressing other concerns that local planning and zoning

commissions face. Lessons learned from this project have already been, and will continue to be, passed along to other

communities through ongoing technical assistance and training programs administered by the CT DEP, the University

of Connecticut Cooperative Extension System, and other agencies and organizations.

References

1. Arnold, C.L. and C.J. Gibbons. 1996. Impervious Surface Coverage: The Emergence of a Key Environmental

Indicator. American Planning Association Journal. 62:2. Chicago, IL.

2. USEPA. 1996. National Water Quality Inventory. Washington, D.C. 20460

3. US Bureau of the Census. 1996.1992 Census of Construction Industries. Manufacturing and Construction Division.

Washington, D.C. 20460

4. Clausen, J.C. and J. Spooner. 1993. Paired Watershed Study Design. United States Environmental Protection

Agency. USEPA 841 -F-93-009.

5. Engdahl, J. 1999. Impacts of Residential Construction on Water Quality and Quantity in Connecticut. University of

Connecticut. Storrs, CT.

6. Ibid.

7. Ibid.

8. Ibid.

9. Ibid.

8
Sources of Phosphorus in Stormwater and Street Dirt from Two Urban

Residential Basins in Madison, Wisconsin, 1994-95

R. J. Waschbusch and W. R. Selbig

U.S. Geological Survey

Middleton, WI

R.T. Bannerman

Wisconsin Department of Natural Resources

Madison, WI

Abstract

Eutrophication is a common problem for lakes in agricultural and urban areas, such as Lakes Wingra and Mendota

in Madison, Wisconsin. This report describes a study to estimate the sources of phosphorus, a major contributor to

eutrophication, to Lakes Wingra and Mendota from two small urban residential drainage basins. The Monroe Basin

empties into Lake Wingra, and the Harper Basin into Lake Mendota. Phosphorus data were collected from streets, lawns,

roofs, driveways, and parking lots (source areas) within these two basins and were used to estimate loads from each

area. In addition to the samples collected from these source areas, flow-composite samples were collected at monitoring

stations located at the watershed outfalls (storm sewers); discharge and rainfall also were measured. Resulting data were

then used to calibrate the Source Loading and Management Model (SLAMM, version 6.3, copyright 1993, Pitt & Vorhees)

for conditions in the city of Madison and determine within these basins which of the source areas are contributing the most

phosphorus.

Water volumes in the calibrated model were calculated to within 23% and 24% of those measured at the outfalls of

each of the basins. These water volumes were applied to the suspended-solids and phosphorus concentrations that were

used to calibrate SLAMM for suspended-solids and phosphorus loads. Suspended-solids loads were calculated to be

within 4% and 17%, total-phosphorus loads within 24% and 28%, and dissolved- phosphorus loads within 9% and 10%

of those measured at the storm-sewer outfall at the Monroe and Harper basins, respectively.

Lawns and streets are the largest sources of total and dissolved phosphorus in the basins. Their combined

contribution was approximately 80%, with lawns contributing more than the streets. Streets were the largest source of

suspended solids.

Street-dirt samples were collected using industrial vacuum equipment. Leaves in these samples were separated out

and the remaining sediment was sieved into >250 urn, 250-63 urn, 63-25 urn, ~25 urn size fractions and were analyzed

for total phosphorus. Approximately 75% of the sediment mass resides in the >250 pm size fractions. Less than 5% of

the mass can be found in the particle sizes less than 63 urn. The >250 urn size fraction also contributed nearly 50% of

the total-phosphorus mass. The leaf fraction contributed an additional 30%. In each particle size, approximately 25% of

the total-phosphorus mass is derived from leaves or other vegetation.

Introduction

Eutrophication is a common problem for lakes in agricultural and urban areas, such as Lakes Wingra and Mendota

in Madison, WI. Primary productivity in northern temperate lakes is most often limited by phosphorus (Schindler 1974;

1977). Urban runoff has been noted to contain high phosphorus concentrations (U.S. Environmental Protection Agency,

1983) that may be increasing the eutrophication. The focus of the study described in this report was to estimate the

sources of phosphorus to Lakes Wingraand Mendotafrom twosmall urban residential watersheds in Madison, WI (Figure

1). This study was done in cooperation with the city of Madison and the Wisconsin Department of Natural Resources.

9
EXPLANATION

<i) Monroe Basin

:z Harper Basin

‘9 Lakeland Basin Outfall

Figure 1. Lakes Wingra and Mendota in Madison, WI.

Lake Mendota and Lake Wingra are both part of the Wisconsin Department of Natural Resources (WDNR) Priority

Watershed Program (Betz and others, 1997). State funding is available to help pay for management aimed at reducing

the amounts of phosphorus and other pollutants discharged to the lakes. The goal of the Lake Mendota Priority

Watershed Project is to reduce the frequency of nuisance algae blooms in the lake from one out of every two days to one

out of every five days. To accomplish this goal, it is estimated that a 50% reduction is needed in the amount of

phosphorus entering the lake. To help reach this target, the Nonpoint Source Control Plan for the Lake Mendota Priority

Watershed Project (Betz and others, 1997) set an objective of reducing phosphorus loading to the lake by20% from urban

areas. The remaining 30% reduction is intended to come from rural phosphorus management.

For this study, phosphorus data were collected from five source areas-streets, lawns, roofs, driveways, and parking

lots-within the two drainage basins from urban residential and commercial areas to estimate loads from each source

area (Table 1). Resulting data were used to calibrate the Source Loading and Management Model (SLAMM, version 6.3,

copyright 1993, Pitt & Vorhees) for conditions in the city of Madison and determine which source areas are contributing

the most phosphorus within these basins. The city is planning to use SLAMM to target specific source areas for

management efforts to meet the 20% phosphorus-reduction objective of the priority watershed project and to meet

requirements of its Wisconsin Pollutant Discharge Elimination System stormwater permit.

10
Table 1. Land-use Characteristics of the Monroe Basin, 1994, and Harper Basin, 1995, in Madison, WI.

[--, source not present]

Monroe Basin Harper Basin

Source area Residential Commercial Residential

Lawn

Roof

Street

Woodlot

Driveway

Park land

Sidewalk

Parking lot

Railroad bed

Total

Acreage Percent of basin

119.8 51.5

26.5 11.4

30.5 13.1

-- -_

10.6 4.6

19.3 8.3

12.5 5.4

.4 .2

5.3 2.3

224.9 96.8

Acreage Percent of basin Acreage

__ _ _ 23.6

2.3 1.0 5.4

1.6 .7 5.3

_ _ _- 3.0

-_ -- 2.1

__ _- .7

__ _- .7

3.4 1.5 .3

_- __ --

7.3 3.2 41.1

Percent of basin

57.4

13.2

13.0

7.3

5.1

1.7

1.7

.7

__

100

Stormwater runoff samples from source areas and the basin outfall were collected from a medium-density residential

watershed draining to Lake Wingra from May to November, 1994 and from a medium-density residential watershed

draining to Lake Mendota from June to November 1995. These runoff samples were used to estimate the phosphorus

and suspended-solids load that each of these source areas and basins contributes. In addition, a third basin, the Lakeland

Basin that drains into Lake Monona, was monitored for lawn runoff in 1995. This basin, which encompasses an older

section of Madison, was sampled in an attempt to determine whether any difference exists between this section of the

city (which has older, smaller lawns) and other areas of the city.

Study-Area Description

The Monroe Basin, monitored during 1994, drains into Lake Wingra. The basin is 232.2 acres, of which 224.9 acres

are residential and 7.3 acres are commercial (Figure 2). Lake Wingra has a surface area of 338.9 acres (1.37 km*) and

a drainage area of 3,889 acres (15.74 km*). About 75% of the Lake Wingra drainage basin is urbanized and about 25%

is composed of forest, prairie, and marsh within the University of Wisconsin Arboretum (Oakes and others 1975).

The Harper Basin, monitored during 1995, drains into Lake Mendota. The Harper Basin is 41 .l acres, all of which

is residential land use (Figure 2). Lake Mendota has a surface area of 9,859 acres (39.9 km*) and has a drainage area

of 138,823 acres (561.8 km*) (Lathrop and others, 1992). Approximately 20% of the Lake Mendota drainage area is

urban, 57% is agricultural, and the remaining 23% is grassland/woodland/marsh/open-water area (Betz and others, 1997).

The Lakeland Basin is approximately 3 miles southeast of the Harper Basin.

In addition to the samples collected from source areas, a monitoring station was located at each basin storm-sewer

outfall to collect flow-composite samples and to monitor discharge and rainfall. The total rainfall amounts for the months

of June through October 1994 at Monroe and July through October 1995 at Harper were 9.24 and 10.67 in., respectively.

These amounts are 64% and 71% of the average from 1961 to 1990 (Brian Hahn, National Weather Service, oral

communication, 1997).

Acknowledgments

We thank all of the volunteers that allowed us to install our sampling equipment in their yards, the City of Madison

Engineering Division and Department of Public Health for their efforts in making this study possible, Jeff Beck of the

USGS for his exceptional field efforts, and Holly Ray and Dr. Bob Pitt at the University of Alabama at Birmingham for

their work analyzing the street-dirt samples. Also, we thank Mary Anne Lowndes of the WDNR and

11
2.05 0.10 bill

ii.;0 KILOMETER

WRANA

.,

.I Residential roof*

~W~~~~] Commercial roof

LawnPark-

&5dloG

Sidewalk

Driveway

Parking lot

mK&-oad*

High-traffic road

Medium-traffic road

Figure 2. Harper and Monroe Basins.

Sm??;.a PI @irind T
Steve Corsi of the USGS for insightful comments that have greatly improved the report. Lastly, we thank Gail Moede and

Aaron Konkol at the USGS for their help with the report editing and preparation of illustrations.

Data-Collection Equipment and Methods

Runoff samples were collected from each source area by use of sampling equipment slightly modified from that

described by Bannerman and others (1993). Brief descriptions of the sampling equipment follow.

Street samplers. The street samplers were grouted into the street approximately 5 ft from the curb (Figure 3). The

sample bottle was covered with a 6-in. concave polycarbonate cap, set flush with the street surface, with a center drain

hole. The bottle and cap were placed into a 6-in. diameter polyvinyl chloride (PVC) sleeve. Water flowed over the top of

the cap and drained through the center hole into a collection bottle. The drain hole could be constricted by a set screw

that controlled the flow rate into the sample bottle.

3/0-inch thread

for removing cap

Concave 4

polycarbonates

‘T

Polycarbonate set ’

screw used to adjusti

size of drain hole

1.5~liter sample bottle

- &inch-diameter

PVC sleeve

- Buick-set grout

a

F--- Undisturbed asphalt

macenal

Figure 3. Schematic of street samplers.

Driveway samplers. Runoff water from driveways was diverted into a sampler by means of a flat piece of clear

plastic, 114 in. high by 1 in. wide by 3 ft long, glued to the surface of the driveway. The sampler consisted of a 1.5-L glass

bottle placed in a lo-in.-diameter protective PVC sleeve set into the ground next to the driveway. A l/2-in.-diameter silicon

tube carried the runoff through a plastic cap covering the PVC sleeve and into the sampler. During the 1994 field season,

the tubing emptied directly into the sample bottle, causing several sample bottles to overfill. To alleviate this problem, in

1995, the tube emptied onto a polycarbonate cap like those used with the street samplers, so that the volume of water

entering the sample bottle could be controlled.

Lawn samplers. Lawn sample bottles received runoff through two 5ft pieces of l/2-in.-diameter PVC pipe placed

flush with the surface of the ground, on a sloping surface, with an angle of about 150 degrees between the two pipes

(Figure 4). Runoff entered the pipes through two slits cut the entire length of pipe. Each pipe was wrapped with fiberglass

13
1 Directicnofwterflcw 1

l/Z-inch

WC cap

l/2+& WCtubing TOD View ,

l-inch-thick 4-1/GIcfI

diameter gray PVC cap

@’ R?’ Tigon tubing

stretdled over

F?!e the l/Z-inch

Side View

Figure 4. Schematic of lawn samplers.

screen to prevent insects and large debris from entering. Wooden clothespins with small pieces of nylon rope held the

pipes in place. Water from the pipes flowed into a sampler through a notched cap. The sampler was a 1- qt glass bottle

placed in a 4-in.-diameter protective PVC sleeve. The cap had a notch to accommodate silicon tubing, which ran from

the end of the PVC collector pipes to the sample bottle.

Roof samplers. Roof samplers were designed to divert a small portion of the water in the gutter downspout to a

sample bottle. A l/4-in.-diameter vinyl tube was attached to the inside of the downspout by means of plastic wire ties.

Each tube went into a 1.5-L glass sample bottle that was placed in a covered lo-in.-diameter protective PVC sleeve.

Because of problems with overfilled sample bottles, the design was changed in the same manner as the driveway

samplers so that the volume of water entering the sample bottle could be controlled.

Parking Lot sampler. The parking lot sampler collected runoff entering a storm-sewer inlet grate. A small portion of

the inlet flow was diverted to a sample bottle by means of a 6-in. trough made of l/2-in.-diameter PVC pipe cut lengthwise and held in place with stainless steel hose clamps attached to the inlet grating. Water drained from the trough

through a tube to a 2.5-gal glass sample bottle hanging from the inlet grate. No samples were collected from parking lots

during 1995.

14
Basin storm-sewer outfall samplers. An automated sampling station was placed at the storm-sewer outfall of both

the Monroe and Harper Basins. In 1994, water level in the basin storm- sewer outfall pipe was measured with a pressure

transducer as water drained into a detention pond. Velocity was measured with an electromagnetic velocity meter. In

1995, stormwater-runoff volumes were computed using a modified Palmer-Bowlus flume design (Kilpatrick and others,

1985). The water level was measured one pipe diameter (36 in.) upstream from the entrance to the flume using a

pressure transducer connected to a nitrogen bubble system. This water level was used in the following equation to

calculate the total discharge through the flume:

Q = a[Ha /D] bd.5,

where

Q is discharge, in cubic feet per second,

a is a constant, 3.685,

b is a constant, 1.868,

H, is the water level above the upstream lip

of the flume, at a distance of one pipe

diameter upstream from the flume

entrance, in feet, and

D is pipe diameter, in feet.

Flow-composite water quality samples were collected using programmable, refrigerated automaticsamplerswith 3/8-

in.-diameter Teflon-lined sample tubing. Rainfall was measured using a tipping-bucket rain gage and was recorded by

a digital data logger.

Stormwater Sample Collection and Processing Protocols

Sample bottles were placed in the source-area samplers as close to the start of each rain event as possible. As the

bottles were being deployed, the sampling equipment was rinsed with deionized water to remove any accumulated surface

dirt. Before the lawn sampler pipes were rinsed, they were cleaned with a small test tube brush. As soon as possible after

runoff had stopped, the sample bottles were collected and the approximate volume of water in each bottle was recorded.

All the bottles from a given source area were composited by pouring water from each bottle into a 5-gal or l-gal

stainless steel, Teflon-coated churn splitter modified from the type described in Ward and Harr (1990). The City of

Madison Department of Public Health Laboratory analyzed a small subsample taken from the churn for suspended solids

and phosphorus.

Street Dirt Collection and Analysis

In addition to stormwater-runoff samples, samples of street dirt were collected with a g-gal wet-dry shop-vacuum using

a 6-in.-wide wand. A section of the street was vacuumed from curb to curb, 10 times across each of 3 streets in the basin,

similar to the technique described by Pitt (1979) and Bannerman (1983). Monroe Street, Glenway Street, and Seneca

Place/Spring Trail/Huron Hill (the latter three are considered one residential street) were sampled during 1994 (Figure

2). Woodward Drive, Nova Way, and Luster Avenue were sampled during 1995. Woodward Drive did not have curbs, so

the sample was collected by vacuuming between wooden 4-by 4-in. blocks placed at the edge of the asphalt on each side

of the street. During the fall, leaves on the street would often plug the vacuum hose. To alleviate this problem, a 6-in. by

2-ft wooden frame was placed with the 6-in. side abutting the curb. Before vacuuming the inside of the frame, the leaves

inside it were collected by hand and placed in the vacuum collection bag. Then the street was vacuumed in the normal

manner.

The dirt samples were dried at 105”C, sieved into size fractions of >250 urn, 250-63 pm, 63- 25 pm, and ~25 urn and

weighed. The sieved samples were sent to the University of Alabama at Birmingham (UAB) for phosphorus analysis. In

addition to total phosphorus, samples collected from the Monroe Basin were analyzed for percentage of vegetative

material. Two independent methods were used to determine the percentage of vegetative material: thermal

15
chromatography and microscopic examination. In thermal chromatography, dirt samples were placed in ovens at

increasing temperatures and the mass that was lost to incineration was determined after each increase in temperature.

The mass loss was compared to the standard temperatures where various substances like leaves, rubber, and paper

burned off. The sample mass lost at the temperature range corresponding to the leaf standards was assumed to be

vegetation. In microscopic examination, samples of the dirt were compared to microscopic pictures of vegetation. More

details of these methods can be found in Ray (1997).

Sources of Phosphorus

Measured Concentrations in Runoff from Source Areas

A total of 25 runoff events were monitored at each basin. Runoff samples were collected from May to November of

1994 at Monroe and from June to November of 1995 at Harper and Lakeland. Driveway samples collected from the

Monroe Basin were excluded because of problems with the sample bottle overfilling (discussed in the methods section).

Summary statistics are listed in Table 2.

Table 2. Concentrations for Suspended Solids, Total Phosphorus, and Dissolved Phosphorus at the Monroe Basin and Harper Basin, 1994-95

[--, concentrations were not used because of problems with the samplers; -, source area not present in basin; mg/L, milligrams per liter]

Statistic

Geometric mean 59 68 51

Coeff. of variation .55 1.17 .97

Mean 85 99 67

Median 75 60 46

Geometric mean 0.79 0.40 0.22

Coeff. of variation .62 1.24 1.23

Mean 1.03 .75 .36

Median .99 .31 .16

Geometric mean 0.37 0.16 0.05

Coeff. of variation .62 1.72 1.47

Mean .52 .40 .14

Median .61 .14 .04

Geometric mean 122 69

Coeff. of variation .37 .68

Mean 132 98

Median 154 88

Geometric mean 1.61 0.24

Coeff. of variation 1.12 .75

Mean 2.34 .31

Median 1.54 .22

Geometric mean 0.77 0.08

Coeff. of variation 1.51 .98

Mean 1.54 .12

Median .81 .08

Lawns Feeder

Street

Collector

street

Source area

Arterial Driveways

street

MONROE BASIN

Suspended solids (mg/L)

65 _ _

.92 _ _

83 --

64 -_

Total phosphorus (mgR)

0.18 -_

1.15 __

.24 __

.17 __

Dissolved phosphorus (mg/L)

0.03 __

1.20 _ _

.05 _-

.03 -_

HARPER BASIN

Suspended solids (mg/L)

34

.93

57

31

Total phosphorus (mg/L)

0.18

.80

.24

.20

Dissolved phosphorus (mg/L)

0.07

1.0

.ll

.07

Parking Pitched Flat

IOtS roofs roofs

51 15 18

1.27 -95 1.21

82 85 35

44 18 20

0.10 0.07 0.13

1.04 .76 .96

.14 .09 .2

.09 .06 .12

0.02 0.02 0.02

1.24 1.22 1.24

.04 .03 .04

.02 .02 .02

17

.96

25

17

0.15

.68

.19

.15

0.08

.83

.ll

.07

The concentration data from the Monroe and Harper Basins seem to exhibit log-normal distributions that are

consistent with urban-runoff concentration datacollected during the Nationwide Urban Runoff Project (U.S. Environmental

Protection Agency, 1983). In such cases, the geometric mean is a better estimate of the central tendency than the

16
arithmetic mean because the geometric mean gives less weight to extremes (Helsel, 1992). Several of the coefficients

of variation in Table 2 have a value greaterthan 1, indicating substantial variability in concentrations within a source area.

The large variation seen in the source-area concentration data could cast doubt on the predictability of the data. For

lawn runoff, the difference between geometric mean phosphorus concentrations from 1994 to 1995 was greater than a

factor of 2; however, the lawn-runoff data collected from the Lakeland Basin are remarkably similar to data collected at

Harper (Table 3), indicating that the variation in lawn-runoff phosphorus concentrations is not random. Primary sources

of phosphorus, such as tree canopy, also could have a large effect on the source-area concentrations measured between

basins. Figure 5 illustrates a trend between the concentration of phosphorus and the percentage of overhead tree canopy

on streets for the Monroe and Harper Basins. Canopy in the Monroe Basin tends to be less than 35%, whereas the

percentage of canopy in the Harper Basin ranges from 5 to 78%. Variation also could be caused by meteorological

factors like rain depth, intensity, or inter-event period or by seasonal variables.

Roof runoff had the lowest geometric mean concentrations of suspended solids, and lawn runoff had the highest total

and dissolved phosphorus concentrations in both the Monroe and Harper Basins (Figures 6 and 7). In addition, patterns

in geometric mean concentrations between source areas within each basin were similar; however, their magnitudes were

very different. The geometric mean concentration of phosphorus for low-traffic streets in the Monroe Basin were about

twice those at the Harper Basin. Conversely, geometric mean phosphorus concentrations for lawn and roof runoff in the

Harper Basin were more than twice as high as those in the Monroe Basin. The beginning of the sampling periods differed

by one month between basins (Monroe Basin in May and Harper Basin in June), and this difference may have caused

some of the variability.

Concentration results for suspended solids and phosphorus from earlier source-area studies in Madison, WI,

Marquette, Ml, and Birmingham, AL (Bannerman and others, 1993; Steuer and others, 1997; Pitt and others, 1995), were

compared to the concentration results from this study. Suspended-solids concentrations in street-runoff samples collected

during the other studies were considerably higher than those in samples collected forthis study. Sandier soils are present

in Marquette that could partially account for this difference. Furthermore, some of the same lawns in the Monroe Basin

were monitored for phosphorus concentrations in the previous Madison study (Bannerman and others, 1993), and both

the dissolved and total phosphorus geometric means calculated for that study were more than three times higher than

those in 1994. Because phosphorus concentrations varied highly from Monroe and Harper Basins, did not closely agree

with each other, and did not agree well with previous studies, the geometric mean of the combined data collected at

Monroe and Harper Basins was used for the modeling phase of this study.

Table3. Rainfall Amountsand Intensities and Total-phosphorus Concentrations from Lawn-runoff Samples for Harperand Lakeland Basins, Madison, WI,

1995

Start of rain

event

(date)

06/26/95

07/05/95

07115195

07/22/95

08/16/95

08/16/95

08128195

10/19/95

HARPER

Rainfall Intensity

(inches) (in/hr)

0.26 0.12

.36 .62

.50 .12

.79 .lO

.61 .43

.38 .29

.80 .19

.32 .07

Total-phosphorus

concentration

OWL)

10.72

1.32

3.61

1.08

1.82

.60

1.39

2.24

Rainfall

(inches)

0.31

.lO

.80

.80

.55

.55

.67

.33

LAKELAND

Intensity Total-phosphorus

(inhr) concentration

OWL)

0.17 9.05

.16 2.06

.lO 2.99

.09 1.35

.94 2.48

.49 .58

.15 1.58

.06 2.59

17
DISSOLVED PHOSPHORUS

TOTAL PHOSPHORUS

I I I I I I I

n

I I I I I I I

10 20 30 40 50 6 0 70 00

Figure 5. Trend between concentration of phosphorous and percentage of overhead tree canopy on streets for Monroe and Harper Basin.

18
Monroe Basin

I

Dl550LVED PHOSPHORUS

I I I I I I I

Of I I I

y

I M I

Lawn5 Low-Traffic* Med.-Traffic

0.25

5treet5

SOLKCE AREA

Streets

TOTAL PHOSPHOR%

LWtl!i Low-Traffic. Me4 -Traff ic’

5treets Streets

SOURCE AREA

DISSOLVED PHOSPHORUS

High-Traffic Parking PItched

5treet5 lot5 ROOf5

SOURCE AREA

Fiat

Roofs

TOTAL PHOSPHORUS

1.6 I I I I I I J I I

1.4 I.

001

0.6

0 2 M

8

M

z3

0

I I I I I I I I I

High..Traffic Parking< Pitched Flat

Streets lot.cJ ROOfS Rook

SOURCE AREA

SUSPENDED 5OLIDS

600. I I I I I I I I I I I I I I I

500 -

100 -

23 x

23 M x

0

I I I I I I I I I I I D I u I

Laws Low-Traffic* Med.-Trafftc High-Traffic Parking Pitched Flat

5treets 5txeet5 5treet5 lot5 RcOfS ROOF5

SOURCE AREA

EXPLANATION

Source-area

concentration

M Geometric mean

Figure 6. Dissolved phosphorous concentrations in Monroe Basin.

19
Dl550LVEU PHO5PHOKIJS

Harper Basin

D1550LVED PHOSPHORUS

0.45 I T I I I I I

0

0.4

SOURCE ARM SOURCE AREA

TOTAL PHOSPHOKUS TOTALPHOSPHOKU5

SOURCE AKEA

0.35

g-2i

0.3

FZ 0.25

d2-2e 0.2

Y

59$ 0.15

-3

I 0 1

z

0.05

0

Roof5

cl

Driveuays

SOUKCEARW

SUSPENDED SOLIDS

0

8

0 0

E 0

0

I I I @ I I I

LaWl5 5trcete Vriveways Roofs

SOURCE AREA

EXPLANATION

0 Source-area *

concentration

$3 Geometric mean

Figure 7. Dissolved phosphorous concentrations in Harper Basin

20
Calibration of the Source Loading and Management Model (SLAMM)

A concentration data base to simulate stormwater quality and theoretical runoff coefficients to simulate runoff volumes

is used in the Source Loading and Management Model (SLAMM). Because large amounts of concentration data and

runoff information were collected during this study, it was an opportunity to calibrate the model’s concentration data base

and improve the runoff coefficients with data collected from the Monroe and Harper Basins.

Calibrating SLAMM with concentration and water-volume data was a three-step process. First, the runoff volume

generated by each source area was calibrated (a critical step because an accurate water volume is essential for

estimating all pollutant loads). Second, sediment was calibrated because sediment concentrations and loads are used

in SLAMM to estimate phosphorus loads. The final step was to calibrate the model for phosphorus concentrations.

A systematic procedure was used to calibrate suspended-solids and phosphorus concentrations in SLAMM. First,

a mass-balance approach compared total measured loads from source areas summed over 25 events to the loads

measured at the outfall. Monitored loads from source areas were calculated using SLAMM-generated water volumes.

Individual source areas were not equipped to measure runoff volumes during an event. Therefore, the accuracy of sourcearea volumes, as assigned by SLAMM, was subject to agreement with the actual volumes measured at the outfall. If the

sum of all source-area volumes closely matched what was measured at the outfall, the individual source-area volumes

assigned by SLAMM were assumed to be correct. Second, source-area concentrations were adjusted to optimize the

mass balance. SLAMM was adjusted after agreement between measured source-area and outfall loads was achieved.

Water-Volume Calibration

Water-runoff volume from each source area for each rain event is calculated with the model. These calculations are

based on the amount of rainfall and a runoff coefficient developed for various rainfall depths for each source area. Sourcearea characteristics such as imperviousness, connectedness (amount of impervious area directly connected to the storm

sewer), and infiltration rates on pervious areas were used to develop runoff coefficients (Pitt, 1987). The volumetric discharges for each source area are then summed for each event. The total runoff volume can be decreased in the model

by using control measures, such as infiltration devices.

SLAMM was used to estimate runoff volume for the 25 storm events from all source areas in each basin. The sum

of the volumes from all of these source areas was compared to the volume measured at the basin storm-sewer outfalls

for these 25 events. Initially, the model overpredicted the water volumes measured at Monroe by a total of 55% (over the

entire study period), whereas it underpredicted those measured at Harper by only 2%. To obtain a balance of

overprediction and underprediction between the basins, the runoff coefficients were adjusted. Historically, more

measurements have been made for runoff from impervious surfaces (Pitt, 1987) and more than 50% of the area within

each basin is pervious, mostly because of residential lawns. Therefore, it was decided that the runoff coefficients for

pervious areas were more uncertain and model calibration could benefit from minor adjustments.

Two sets of runoff coefficients are available for pervious areas; one is designed to represent clayey soils, and the

other represents sandy soils. The predicted water volumes mentioned above were determined using the runoff coefficients

for clayey soils (based on soil maps). Changing the pervious classification from clayey to sandy resulted in SLAMM

underprediction of water volumes; approximatelya4% and a42% underprediction at the Monroe and Harper Basin stormsewer outfalls, respectively. A much better agreement was achieved at Monroe by assuming that the original soil

classification was incorrect. Sandy and clayey runoff coefficients, available to the model, probably represented two

extremes, and more realistic runoff coefficients fell somewhere between these two coefficients.

Lawn-runoff data collected from Monroe and Harper Basins were used to create runoff coefficients that more

accurately represent the pervious conditions found in Madison. First, the rainfall depth sufficient to initiate runoff in

SLAMM was changed using data on the amount of stormwater in the lawn-sample bottles after each event. For rainfall

amounts less than approximately 0.3 in., the bottles were less than 10% filled. From this observation, 0.3 in. was

established as the minimum precipitation required to initiate runoff. However, the runoff coefficient table for clayey soils

21
used in SLAMM resulted in 10% runoff for a rainfall depth of 0.2 in. Hence, SLAMM was changed to initiate runoff at 0.3

in. rather than 0.2 in. of precipitation.

In addition to the change described above, a trial-and-error approach was used to change the coefficients until

optimum agreement was reached between water volumes predicted in SLAMM and those measured at the Monroe and

Harper storm-sewer outfalls. The resulting coefficients were between those for sandy and clayey soils and were

approximately two-thirds the value for clayey soils. Figure 8 shows how the new “Madison” runoff coefficients compare

to the sandy and clayey coefficients.

0.45

0.4

0.35

0.3

r=

g 0.25

$j

E

g 0.2

B

2

2 0.15

0.1

0.05

0 4

__f__ Clayey soils

-+ - . Mad&on &I5

0 0.5 1 1.5 2 2 5 3 3.5 4 4.5 E

PRECIPITATION, IN INCHES

Figure 8. Madison runoff coefficients compared to sandy and clayey coefficients.

Based on the revised Madison runoff coefficients, SLAMM overpredicted storm-sewer outfall volumes at Monroe by

23% and underpredicted Harper storm-sewer outfall volumes by 24% (Table 4). The Madison coefficients also produced

consistent lawn-runoff contributions in both basins, approximately 20% of the total volume. It is expected that the

percentage of lawn contribution would be similar for both basins because they have nearly the same percentage of lawn

area.

22
Table 4. Percentage Difference in Cumulative Modeled Water Volumes Compared with Measured Outfall Water Volumes Using Three Soil Types,

Madison, Wi.

Basin

Monroe

Harper

Sandy soils Clayey soils

VW (“4

-4 55

-42 -2

Madison soils

(“W

23

-24

Sediment Calibration

Once the runoff volumes were calibrated, SLAMM was used to estimate sediment loads for the 25 events in each

basin. With the exception of streets, a data base of sediment concentrations for each source area is used in SLAMM and

these concentrations are applied to the water volumes to derive a load. Sediment concentrations from streets are

computed by a wash-off function that is related to a street-dirt accumulation rate.

A mass-balance approach was used to test the source-area concentrations within each basin with those measured

at the storm-sewer outfall. Source-area loads were computed by multiplying the water volumes produced from SLAMM

by the concentrations measured at the source areas for each event and then summing these event loads. Sidewalks and

woodlots were two of the larger unmonitored source areas in each basin, accounting for 12% and 1% of the water volume

produced at Monroe and 7% and 2% at Harper, respectively. To add sidewalks to the load estimates, concentrations

measured at driveways were applied to estimates at sidewalks to create a sidewalk load. Woodlot concentrations were

estimated by use of data collected in an undeveloped urban site near Superior, WI (Steuer and others, 1997). The sourcearea loads were 39% lower and 60% lower than the measured load at the storm- sewer outfall in the Monroe and Harper

Basins, respectively. This difference between source-area and storm-sewer outfall loads indicates that one or more source

areas within each basin were not effectively monitored.

Streets were the most likely source area to be ineffectively monitored. Street samplers were placed approximately

5 ft away from the curb to prevent gutter flow into the sampler because gutter flow usually contains a mixture of water

from several source areas. Other street studies (Pitt, 1979) have estimated that 90% of the dirt on residential streets in

good condition with little to no parking accumulates within 3 ft of the curb. A larger amount of dirt can sometimes collect

along the curb itself rather than in the driving lane. Some of this dirt could have been deposited on the driving lane, and

turbulence from passing vehicles and wind may have moved it to the curb. Most street dir-t falls within 1 to 2 ft of the curb

if the driving lane is next to the curb (Pitt, 1979). This information suggests that the street samplers in the Monroe and

Harper Basins were too far from the curb (5 ft) to representatively collect the particulate dirt from the streets.

For the reasons previously described, a trial-and-error approach was used to select a street- sediment concentration

that more accurately reflected the street sediment entering the storm sewer. The final suspended-solids concentrations

for streets were increased by a factor of 5. Applying this factor to the simulated street suspended-solids concentration

during each storm event allowed the sum of source-area loads to be within 7% and 9% of the storm- sewer outfall loads

at Monroe and Harper, respectively (Table 5). The geometric means for the revised street suspended-solids

concentrations were 340 and 325 mg/L for low- and high-traffic streets, respectively. These values were within 5% of

those measured at both Marquette, Ml (Steuer and others, 1997), and Madison, WI (Bannerman and others, 1993).

The geometric means of the observed suspended-solids concentrations, excluding streets, for the 25 storm events

at Monroe and Harper Basins were placed into the SLAMM data base (Table 6). The suspended-solids concentrations

for streets were not as easily altered because they are determined by dirt accumulation and wash-off functions in the

model. Entering the geometric means enabled the model to more accurately predict the loads measured at the stormsewer outfall. After summing the 25 events, sediment loads predicted by SLAMM were 17% lower at Monroe and 32%

lower at Harper compared to the measured storm-sewer outfall loads.

To improve the match between measured and simulated storm-sewer outfall loads, the delivery coefficients were

removed from SLAMM calculations, essentially assuming 100% delivery from source area to storm-sewer outfall. The

delivery coefficients had been added in a previous calibration study to force a match to the storm-sewer outfall

23
numbers. This adjustment resulted in a 4% and 17% undersimulation between storm-sewer outfall loads of suspended solids calculated by SLAMM and those measured at the storm-sewer outfall for Monroe and Harper,

respectively (Table 5).

Phosphorus Calibration

One objective in calibrating phosphorus concentrations in SLAMM was to ensure that the Monroe and Harper Basins

were accurately represented by the monitored source areas. The sum of source-area loads for total phosphorus for the

25

Table 5. Percentage Difference in Cumulative Source-area Sediment Loads, Before and After Sediment Adjustment, and Modeled and Measured

Sediment Loads at the Basin Outfall, Madison, Wi. [Loads computed as suspended solids; %, percent]

Cumulative source area compared

with storm-sewer outfall

Basin Suspended Suspended Modeled

solids before solids after compared with

adjustment adjustment measured

(“4 w (“N

Monroe -39 -7 -4

Harper -60 -9 -17

Table 6. Suspended-solids Concentrations Used to Calibrate the Source Loading and Management Model for Basins in Madison, Wi. [mg/L, milligrams

per liter: --, a series of algorithms and coefficients are used in the model to calculate a suspended-solids concentration for street runoffj

Suspended solids (mg/L)

Source area Residential Commercial

Driveways 34 34

Lawns 84 84

Parking lots 51 51

Streets -- --

Woodlots 15 15

Roofs 16 18

Sidewalks 34 34

storm events was nearly identical to the storm-sewer outfall load (Table 7). The difference was larger for dissolved

phosphorus, but no information was available to determine what adjustments should have been made to reduce the

difference. For this reason, the unadjusted concentrations were entered into the SLAMM data base.

Table7. Percentage Difference Between Cumulative Source Area Versus Outfall Loads and Modeled Results Versus Outfall Loads, after Calibration of

the Source Loading and Management Model for Basins in Madison, Wi. v, percent]

Cumulative source area Model results after

versus calibration versus stormstorm-sewer outfall sewer outfall

Basin Phosphorus load

Dissolved Total Dissolved Total

(“W W) v-1 (%I

Monroe 39 -1 -9 -24

Harper 35 4 -10 -28

The model simulates total phosphorus loads by adding the dissolved phosphorus and particulate phosphorus loads.

For all source areas except streets, particulate-phosphorus concentrations were calculated using total- and dissolvedphosphorus and sediment concentrations measured at the Monroe and Harper Basins. To be consistent with calibration

24
procedures, particulate-phosphorus concentration for street runoff was calculated using the adjusted value for sediment

(an increase by a factor of 5). Changing the phosphorus concentrations resulted in SLAMM undersimulation of dissolved

and total phosphorus by 9% and 24% at the Monroe storm-sewer outfall and 10% and 28% at the Harper storm-sewer

outfall, respectively.

The dissolved- and particulate-phosphorus concentrations entered into the SLAMM data base are listed in Tables 8 and

9. Significant changes in dissolved-phos-phorus concentrations (Table 8) were observed for lawns (from 0.22 to 0.53

mg/L), streets (from 0.39 to 0.12 mg/L), woodlots (from 0.25 to 0.01 mg/L), and sidewalks (from 0.60 to 0.07 mg/L). With

the exception of streets, where the particulate-phosphorus concentrations in runoff decreased, particulate-phosphorus

concentrations increased significantly (Table 9).

Table 8. Dissolved-phosphorus Concentrations Used to Calibrate the Source Loading and Management Model for Basins in Madison, Wi.

[mg/L, milligrams per liter]

Dissolved phosphorus (mg/L)

Source-area

Driveways

Lawns

Parking lots

Streets

Woodlots

Roofs

Sidewalks

Residential Commercial

0.07 0.07

53 .53

.02 .02

.12 .03

.Ol .Oi

.04 .02

.07 .07

Table 9. Particulate-phosphorus Concentrations Used to Calibrate the Source Loading and Management Model for Basins in Madison, Wi.

[mg/kg, milligrams per kilogram]

Source area

Driveways

Lawns

Parking lots

Streets

Woodlots

Roofs

Sidewalks

Particulate phosphorus (mgkg)

Residential Commercial

2,649 2,649

4,943 4,943

1,467 1,467

569 409

5,000 5,000

3,777 7,946

2,649 2,649

Distribution of Source-Area Loads

The distribution of suspended-solids and total- and dissolved-phosphorus loads for source areas in the Monroe and

Harper Basins using measured source-area concentrations multiplied by SLAMM-generated water volumes is shown in

Table 10. The distribution of water volumes is nearly identical at Monroe and Harper Basins. The percentage of the total

basin represented by each source area is similar for both basins (Table 1); thus, one should expect to see similar relative

volumes of water calculated from both basins. Streets contributed most of the suspended-solids loads at both Monroe

and Harper Basins, generating 81% and 73%, respectively. Lawns contributed more than 10% of the solids loads at both

basins. The phosphorus loading, however, was quite different. Lawns in the Harper Basin generate more than two-thirds

of the phosphorus loads, whereas phosphorus in the Monroe Basin is more evenly distributed between lawns and streets.

These differences in load distribution are the result of the measured phosphorus concentrations, especially for lawns,

which are much higher for the Harper Basin (Table 2).

25
Table 10. Distribution of Loads Based on Measured Values at Monroe and Harper Basins, Madison, Wi, and Incorporating the Suspended-solids Adjustment

[N/A, source area not present; %, percent abundance; --, value less than 0.5 percent]

Source area

Lawns

Streets

Driveways

Sidewalks

Parking lots

Roofs

Parks

Woodlots

Other

Total

Water

volume’

(“W

21

37

18

7

3

11

3

N/A

311,122

HARPER

Suspended

solids (%)

15

732

7

3

-_

__ _ _

N/A N/A

3,598 9

Total

phosphorus

WI

67

14

9

4

1

3

2

Dissolved

phosphorus

(“A)

71

11

9

3

__

4

2

_ _

N/A

5

MONROE

Water Suspended Total

volume (%) solids (“9) phosphorus

woo)

20

38

12

14

6

7

3

N/A

1

2,417,341

10 hi

*81 37

2 5

3 5

2 1

-_ 1

2 7

N/A N/A

__ --

26,045 70

Dissolved

phosphorus

WI

45

39

4

4

__

7

N/A

__

33

‘.Water volume totals expressed in cubic feet; all other totals expressed in pounds.

2Street-runoff concentrations multiplied by 5.

The suspended-solids load distribution at the Monroe Basin in 1994 is similar to the distribution observed in a 1991

study (Bannerman and others, 1993). Streets contributed 80% of the total basin suspended-solids load in 1991 and 81%

in 1994. Lawns also were comparable, contributing 7% and 10% of the total basin suspended-solids load in 1991 and

1994, respectively. Total and dissolved phosphorus, however, were very different. During the 1991 study, the proportion

of the total-phosphorus load from streets (58%) outweighed that for lawns (14%). The same was true in 1991 for dissolved

phosphorus, where streets produced 46% and lawns22% of the basin load. However, most total- and dissolved-phosphorus loading in 1994 was attributed to lawns rather than streets. Streets and lawns, in 1994, generated 37% and 44% of

the total-phosphorus load and 39% and 45% of the dissolved- phosphorus load in the Monroe Basin. The difference in

distributions between the two studies is possibly due to differences in sampling methodology. The street-sampler design

was modified for the 1994 study to eliminate a first-flush effect, where the sample bottle would quickly fill with stormwater

and act as a sediment trap for the remaining duration of the storm event. Also, during the 1994 study, 25 events were

monitored, whereas only 10 events were monitored in 1991. This larger sample size in 1994 improves confidence in the

loading-distribution estimates.

Distribution of suspended-solids, total-phosphorus, and dissolved-phosphorus loads estimated by SLAMM are given

in Table 11. The distribution of loads is consistent with the distribution of measured loads shown in Table 10. For each

constituent, slightly less total load was simulated with SLAMM than calculated using the measured concentrations (other

than suspended solids from streets), yet the distributions of each constituent were similar. Streets and lawns contribute

nearly all of the suspended-solids load for the entire basin. Streets alone contribute more than 75% of the suspended

solids at both Monroe and Harper Basins. Additionally, the significance of lawns as generators of phosphorus is again

noted in SLAMM simulations. Lawns in the Harper Basin contribute 52% and 61% of total and dissolved phosphorus

loads, and lawns in the Monroe Basin contribute 49% and 57%. Streets contribute the second largest phosphorus loads

(about 25%), whereas driveways and sidewalks combined contribute approximately 10%.

The distribution of suspended solids and total and dissolved phosphorus for source areas in the Monroe and Harper

Basins using measured source-area concentrations multiplied by SLAMM-generated water volumes is shown in Table

12. Only loads for the source areas measured are shown in Table 12; concentrations of suspended solids in street runoff

have not been adjusted. These source areas accounted for 82% and 90% of the total water volume from the Monroe and

Harper Basins, respectively.

26
Table 11. Distribution of Loads from Model Simulation Results at Monroe and Harper Basins, Madison, Wi. [N/A, source area not present; %, percent

abundance; --, value less than 0.5 percent]

Source area

Lawns

Streets

Driveways

Sidewalks

Parking lots

Roofs

Parks

Woodlots

Other

Total

Water

volume

(“W

21

37

18

7

3

11

3

N/A

311,122

HARPER MONROE

Suspended Total Dissolved Water Suspended Total

solids (%) phosphorus QhOSQhoruS volume (“7’0) solids (%) phosphorus

v4 w 6)

11 52 61 20 12 49

81 32 24 38 77 26

4 8 7 12 3 5

1 3 3 14 3 6

1 1 6 2 1

1 3 2 7 1 2

_- 2 2 3 2 8

-- 1 _ _ N/A N/A N/A

N/A N/A N/A 1 1 2

3,170 7 4 2,417,341 20,814 60

Dissolved

QhOSQhOrus

(=a

57

22

4

5

__

9

N/A

2

29

‘.Water volume totals expressed in cubic feet; all other totals expressed in pounds.

Table 12. Distribution of Loads from Monitored Source Areas Only, Based on Unadjusted Concentrations at the Monroe And Harper Basins, Madison, Wi.

[ %, percent abundance; percentage columns may not add up to 100% because of independent rounding]

Source area Water

volume

rw

Lawns 23

Streets 41

Driveways 20

Parking lots 4

Roofs 12

HARPER MONROE

Suspended Total Dissolved Water Suspended Total Dissolved

solids QhOSQhOrUS phosphorus volume solids QhOSQhOrUS phosphorus

(%) (“4 w (W W (“W w

41 70 75 24 28 56 69

43 20 15 46 53 33 21

10 7 6 14 9 7 8

3 1 0 7 7 2 1

3 3 4 9 3 2 1

The suspended-solids distributions shown in Table 12 differ from Tables 10 and 11, in that the significance of lawns

as a source increases and the significance of streets as a source decreases. Streets are still the largest source of

suspended solids in both basins. The phosphorus distributions also change, but not as much as the suspended solids

because the measured phosphorus concentrations were used in all three tables (Tables 1 0, 1 1, and 12). The significance

of lawns as a source increases slightly, and streets are a slightly larger source in some cases, and in others, are slightly

smaller sources. Results shown in Table 12 indicate that the adjustments made to suspended-solids concentrations in

street runoff do not greatly affect the phosphorus distributions in the basins.

Sediment and Phosphorus Mass in Street-Dirt Samples

Approximately 75% of the total sediment mass in the street-dirt samples originated in the >250 urn size fraction,

whereas the smaller fractions (~63 urn) made up less than 5%. Material composed of leaves, twigs, and other organic

debris also were measured, contributing, on average, less than 10% of the total sediment mass of the sample (Figure

9).

Like sediment mass, the largest amount of total phosphorus was found in the >250 pm size fraction (nearly

50%) (Figure 9). Combining this size fraction with the leaf fraction, about 80% of the total phosphorus is

accounted for. The contribution of total phosphorus mass decreased as the size fraction decreased. Other

studies have shown that large phosphorus concentrations correspond with small particle sizes because of the

high surface area to mass ratio for small particles (Sartor and Boyd, 1972).

27
80 I I I I

Sediment

60 Total phosphorus

I

>250 Leaves

PARTICLE SIZE, IN MICROMETERS

Figure 9. Relations between sediment and total-phosphorus mass from street-dirt samples for five particle-size fractions for basins in Madison, WI

However, the bulk of the phosphorus phosphorus load results from the greater particle-size fractions (Ray, 1997).

Approximately 25% of the total phosphorus mass in each size fraction can be attributed to leaves (Ray, 1997).

A recent study of particle-size distribution in stormwater at the Monroe storm-sewer outfall demonstrated that most

of the solids are in the particle sizes ~63 ?m (Greb and Bannerman, 1997). This distribution is the opposite of the particlesize distribution observed for the street dirt collected in this study. These results indicate either a loss of the larger

particles somewhere between the street and the outfall or a problem in collecting larger particles in the runoff samples.

Most of the larger particles (>63 ?m) might settle out before reaching the storm-sewer outfall. Street sweeping,

resuspension onto street terraces, and catch basins can remove these particles from the streets before they reach the

storm sewer. Also, the transport of large particles in a storm sewer is not as efficient as the transport of smaller, more

mobile particles. Large sediment particles may become trapped or part of the bedload before reaching the sampler.

Bedload is not sampled efficiently by the automatic samplers described earlier in this report.

Summary and Conclusions

Concentrations of suspended solids, total phosphorus, and dissolved phosphorus were collected from various source

areas at two urban residential basins in Madison, WI. To represent a range of source-area concentrations for urban

residential basins in Madison, the geometric means of the combined concentration data from the Monroe and Harper

Basins were incorporated into the urban-runoff model, SLAMM.

Source-area suspended solids and phosphorus loads from the Monroe and Harper Basins were determined based

on measured concentrations that were multiplied by water volume estimated by use of SLAMM. Collected data were used

to calibrate and increase confidence in water volumes, suspended solids, and phosphorus source-area loads estimated

by SLAMM. The calibrated model calculated water volumes to within 23% and 24% of those measured at the outfalls of

28
the Monroe and Harper Basins. These calibrated water volumes were then applied to the calibrated suspended-solids

and phosphorus concentrations entered into the SLAMM data bases. Suspended-solids loads were estimated by the

calibrated SLAMM to be within 4% and 17%, total-phosphorus loads within 24% and 28%, and dissolved-phosphorus

loads within 9% and 10% of those measured at the storm-sewer outfall to the Monroe and Harper Basins, respectively.

Streets and lawns are the largest contributors of suspended-solids, total-phosphorus, and dissolved-phosphorus loads

in a residential urban basin. Lawns are the largest contributors of total and dissolved phosphorus; however, streets

contributed nearly 40% of the basin load, as seen in the Monroe Basin. Streets were found to be the largest source of

suspended solids.

There was a large difference between geometric mean concentrations of phosphorus in lawn runoff from 1994 to

1995. Phosphorus data collected from lawns in the Harper and Lakeland Basins during 1995 are remarkably similar, which

suggests that the phosphorus concentration in lawn runoff is affected by some variable or variables that are not yet

understood.

Street-dirt samples indicate that approximately 75% of the sediment mass resides in the >250 pm particle-size

fraction. Less than 5% of the mass can be found in the particle sizes less than 63 urn. The >250 urn particle-size fraction

also contributed nearly 50% of the total- phosphorus mass, and the leaf fraction contributed an additional 30%. In each

particle-size fraction, approximately 25% of the total-phosphorus mass is derived from leaves or other vegetation.

A possible limitation of this study may be that in order for the sum of the source-area loads to match the basin-outfall

loads, it was assumed that the concentrations of suspended solids in street runoff were about 5-times higher than the

concentrations measured. However, the analysis of load distributions based onlyon unadjusted monitoredconcentration

data shows little change in the distributions. In addition, samples from more rain events were collected in this study than

previous source-area studies. Also, improved data-collection equipment were used during this study. Both of these factors

lead to greater confidence in the study results.

Most of the measured suspended-solids concentrations were lower than those measured from previous studies.

However, when comparing concentration results in this study to results from earlier studies, it is important to note that

with the exception of the Marquette study, previous studies used earlier generation source-area sampling equipment. In

Marquette, Ml, the soils are considerably more sandythan those in Madison, which may explain why the suspended-solids

concentrations determined for the Marquette study are higher than those from Madison even though both studies used

the same sample-collection equipment.

The recalibration of the SLAMM model results in an improved model that should more accurately simulate phosphorus

and sediment runoff loads in Wisconsin than the earlier version of the model. The newly created lawn-runoff coefficients

for Madison represent a compromise between the two previous soil-type options available for model input, which probably

represented runoff extremes. The runoff coefficients calculated for Madison should probably be applied to most urban

lawns in Wisconsin unless soils are known to be either sandy or clayey. The phosphorus- and sediment-concentration

data bases created for this study are the largest to date using the most advanced source-area sample collection

technology available.

References

Andren, A.W., and Stolzenburg, T.R., 1979, Atmospheric deposition of lead and phosphorus on the Menomonee River

watershed-Volume 8, The IJC Menomonee River Watershed Study: U.S. Environmental Protection Agency,

EPA-905/4-79-029-H, 98 p.

Bannerman, R.T., Baun, K., Bohn, M., Hughes, P.E., and Graczyk, D.A., 1983, Evaluation of urban nonpoint source

pollution management in Milwaukee County, Wisconsin-Volume I, Urban stormwater characteristics, pollutant sources

and management by street sweeping: U.S. Environmental Protection Agency, Water Planning Division, PB-84-114164,

191 p.

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Bannerman, R.T., Owens, D.W., Dodds, R.B., and Hornewer, N.J., 1993, Sources of pollutants in Wisconsin stormwater:

Water Science and Technology, v. 28, no. 3-5, p. 241-259.

Betz, CR., Lowndes, M.A., and Porter, S., 1997, Nonpoint source control plan for the Lake Mendota priority watershed

project-Project summary: Wisconsin Department of Natural Resources, WT-481-97, 16 p.

Cullen, R.S., and Huff, D.D., 1972, Determination of land use categories in the Lake Wingra Basin: US-International

Biological Program, Eastern Deciduous Forest Biome Program, Memo Report 72-43, 17 p.

Dong, A., Simsiman, G.V., and Chester, G., 1983, Particle size distribution and phosphorus levels in soils, sediment and

urban dust and dirt samples from the Menomonee River watershed, Wisconsin, USA: Water Research, v. 17, no. 5, p.

569-577.

Greb, S.R., and Bannerman, R.T., 1997, Influence of particle size on wet pond effectiveness: Water Environment

Research, v. 69, no. 6, p. 1134-l 138.

Helsel, D.R., and Hirsch, R.M., 1992, Statistical methods in water resources: Amsterdam and New York, Elsevier, 529

PKilpatrick, F.A., Kaehrle, W.R., Hardee, J., Cordes, E.H., and Landers, M.N., 1985, Development and testing of highway

storm-sewer flow measurement and recording system:

U.S. Geological Survey Water-Resources Investigations Report 85-4111, 98 p.

Kunz, K.W., 1980, Atmospheric bulk precipitation in the Great Lakes basin: Environment Canada, Scientific Series 115,

28 p.

Lathrop, R.C., Nehls, S.B., Brynildson, CL., and Plass, K.R., 1992, The fishery of the Yahara Lakes: Wisconsin

Department of Natural Resources, Technical Bulletin 181, 214 p.

Legg, A.D., Bannerman, R.T., and Panuska, J., 1996, Variation in the relation of rainfall to runoff from residential lawns

in Madison, Wisconsin, July and August 1995: U.S. Geological Survey Water-Resources Investigations Report 96-4196,

11 p.

Murphy, T.J., 1974, Sources of phosphorus inputs from the atmosphere and their significance to oligotrophic lakes:

University of Illinois Water Resources Center, Research Report 92, 41 p.

Oakes, E.L., Hendrickson, G.E., and Zuehls, E.E., 1975, Hydrology of the Lake Wingra Basin,

Dane County, Wisconsin: U.S. Geological Survey Water-Resources Investigations 17-75, 31 p,

Pitt, R., 1979, Demonstration of nonpoint pollution abatement through improved street and sewerage cleaning: Cincinnati,

Ohio, U.S. Environmental Protection Agency, EPA/600/2-79/161, 270 p.

-1987, Small storm urban flow and particulate washoff contributions to storm-sewer outfall discharges: University of

Wisconsin-Madison, Dept. of Civil and Environmental Engineering, 513 p.

Pitt, R., Field, R., Lalor, M. and Brown, B. 1995, Urban stormwater toxic pollutants-Assessment, sources, and

treatability: Water Environment Research, v. 67, no. 3, p. 260-275.

Prentki, R.T., Rogers, D.S., Watson, V.J., Weiler, P.R., and Loucks, O.L., 1977, Summary tables of Lake Wingra basin

data: University of Wisconsin-Madison, Institute for Environmental Studies, IES Report 85, 89 p.

Ray, H., 1997, Street dirt as a phosphorus source in urban stormwater: University of Alabama at Birmingham, Department

of Civil Engineering, 125 p.

30
Ryden, J., Syers, J. and Harris, Ft., 1972, Nutrient enrichment of runoff waters by soils, phase I- Phosphorus enrichment

potential of urban soils in the city of Madison: University of Wisconsin-Madison, Department of Soil Science, Technical

Report OWRR-A-038-WIS, 70 p.

Sartor, J.D., and Boyd, G.B., 1972, Water pollution aspects of street surface contaminants: U.S. Environmental Protection

Agency, EPA-R2-72-081,237 p.

Schindler, D.W., 1974, Eutrophication and recovery in experimental lakes-Implications for lake management: Science,

v. 184, p. 897-899.

-1977, Evolution of phosphorus limitation in lakes: Science, v. 195, p. 260-262.

Steuer, J.J., Selbig, W.R., and Hornewer, N.J., 1997, Sources of contamination in an urban basin in Marquette, Michigan

and an analysis of concentrations, loads, and data quality: U.S. Geological Survey Water-Resources Investigation Report

97-4242,25 p.

U.S. Environmental Protection Agency, 1983, Results of the Nationwide Urban Runoff Program, volume l-Final report:

Water Planning Division, Washington, D.C., NTIS PB#84-185552, 200 p.

Ward, J.R., and Harr, C.A., eds., 1990, Methods for collection and processing of surface-water and bed-material samples

for physical and chemical analyses: U.S.Geological Survey Open-File Report 90-140, 71 p.

31
Using Biological Criteria to Assess and Classify Urban Streams and Develop

Improved Landscape Indicators

Chris 0. Yoder and Robert J. Miltner

Ohio EPA, Division of Surface Water

Ecological Assessment Unit

Groveport, Ohio 43125

Dale White

Ohio EPA, Division of Surface Water

Information Resources Management Section

Columbus, Ohio 43216-0149

This study consisted of a quantitative analysis of the relationship between the Index of Biotic Integrity (IBI), an

indicator of urban land use, and a qualitative analysis of overlying stressors in six of the major metropolitan areas of Ohio.

A database consisting of 267 sampling locations was extracted from the Ohio EPA statewide biological and habitat

database. Most of these sites were sampled between 1990 and 1998 and contained watershed areas less than 50 mi.‘,

with most draining less than 20 mi.‘. A negative relationship between IBI and urban land use was observed in four of the

six areas, whereas little or no relationship was seen in two areas. For each area, the highest percentage of urban land

use that corresponded to minimum attainment of the applicable warmwater habitat IBI biocriterion ranged from 1%

(Cleveland/Akron) to 12% (Dayton) for the regression line, and 15% (Cleveland/Akron) to 58% (Columbus) as the highest

%urban land use where the IBI biocriterion was attained at any given site. No significant linear relationship was found

in either the Toledo or Youngstown areas, and only a weak relationship was visually apparent for the Toledo streams.

The lack of association was due to the strong presence of overlying stressors (e.g., legacy pollutants, sewage discharges,

combined sewer overflows) that resulted in very low IBI values at sites with lower levels of urbanization. The percentage

of urban land use explained approximately 35% of the variation in IBI scores in the regression model when these impact

types were excluded (compared to 11% when included). The maximum %urban land use that commonly corresponded

to attainment of the warmwater habitat IBI biocriterion based on inspection of the scatter plot was approximately 26%.

Only a very few sites exhibited attainment at urban land uses between 40-60% and none occurred above 60%. These

former sites had either an intact, wooded riparian zone, a continuous influx of groundwater, and/or the relatively recent

onset of urbanization. These results indicate that it might be possible to mitigate the negative effects of urbanization by

preserving or enhancing near and instream habitats, particularly the quality of the riparian buffer zone. The results also

suggest that there is a threshold of watershed urbanization (e.g., >60%) beyond which attainment of warmwater habitat

is unlikely. This threshold is not the same in all watersheds and it can occupy a rather wide range. It is affected by cofactors such as pollutant loadings, watershed development history, chemical stressors, and watershed scale influences

such as the quality of the riparian buffer and the mosaic of different types of land use. Thus, single-dimension urban land

use indicators, such as watershed imperviousness, are not sufficiently precise or robust as a single indicator of use

attainability. The further development and refinement of multiple indicators of watershed urbanization has merit from a

management and decision-making standpoint. We suggest that co-factors, in addition to more refined urban land use

indicators, be better developed. More precise definitions of different urban land uses are also needed to better

understand and respond to the water quality management challenges posed in existing and developing urban areas.

32
Introduction

The health and well-being of the aquatic biota in surface waters is an important barometer of how effectively we are

achieving the goals of the Clean Water Act (CWA); namely the maintenance and restoration of biological integrity, and

the basic intent of water quality standards. States designate water bodies for beneficial uses (termed designated uses)

that, along with chemical, physical, and biological criteria, assure the protection and restoration of aquatic life,

recreational, and water supply functions and attributes. Biological criteria are the principal tool for determining impairment

of designated aquatic life uses as defined by the Ohio WQS (Ohio Administrative Code 3745-l). As such,

bioassessments play a central role in the Ohio Nonpoint Source Assessment (Ohio EPA 1990; 1991), the biennial Ohio

Water Resource Inventory (305b Report; Ohio EPA 1998), and watershed-specific assessments, of which Ohio EPA

completes between 6 and 12 each year. Biological criteria represent a measurable and tangible goal, against which the

effectiveness of pollution control and other water quality management efforts can be judged. However, biological

assessments must be accompanied by appropriate chemical/physical measures, land use characterization, and pollution

source information necessary to establish linkages between stressors and the biological responses (Yoder and Rankin

1998). Biological criteria in the Ohio WQS also supports the determination of appropriate aquatic life use designations

for individual water bodies, provides for a “reality check” on the application of surrogate indicators, assesses cumulative

impacts, extends anti-degradation concerns to nonpoint sources and habitat influences, defines high quality waters, and

serves as a meaningful indicator in the management of regulatory programs for environmental results. This provides a

means to incorporate the broader concept of water resource integrity (Karr et al. 1986) in policy and planning while

preserving the appropriate roles of the traditional chemical/physical and toxicological approaches developed over the past

three decades.

We, and others at Ohio EPA, have previously described the status of Ohio’s streams and rivers as affected by

watershed urbanization (Yoder et al. 1999; Yoder and Rankin 1997; Yoder 1995). Small watersheds are especially

impacted, as illustrated by Yoder and Rankin (1997), where no headwater streams in established urban settings

throughout Ohio attained the minimum CWA benchmark use designation of warmwater habitat. This finding has led to

the perception that the impairment of beneficial aquatic life uses in these small watersheds is intractable, at least within

the constraints of current land use policies, restoration technologies, and funding levels. Together, these factors present

potentially significant barriers to the objective of fully restoring degraded watersheds or upgrading urban streams that are

presently designated for less than fishable and swimmable uses.

Headwater streams are critical to watershed functioning in that they serve as the principal interface between runoff

from land use and receiving streams. The ability of a headwater stream to physically filter and biologically assimilate the

primary and secondary effects of pollutants is a function of habitat quality and the structure of the biological system. A

healthy headwater stream ecosystem is characterized by good habitat and a well balanced assemblage of aquatic

organismsand plants, one which processes external inputs in a manner which promotes high quality downstream exports.

These exports include good quality water and high value biomass, both of which positively impact the ability of

downstream waters to deliver quality goods and services (e.g., water supply, recreation, waste assimilation, water

retention, ecological values). A degraded headwater stream ecosystem is characterized by poor habitat and an

assemblage of aquatic organisms and plants that processes external inputs in a manner which promotes low quality

downstream exports. Thus in this latter scenario, the effects from urban runoff can accumulate in a downstream direction

and adversely affect water quality and ecosystem goods and services in larger water bodies. In Ohio, more than 78%

of stream miles drain less than 20 mi.2 and are classified as headwater streams. While these may individually seem less

significant than larger water bodies, they are collectively the most numerous and perhaps important stream type. In many

ways, and in a collective sense, headwater streams are analogous to the capillaries of the human circulatory system

where essential product transport and waste assimilation functions are accomplished. Certainly the finding that a high

proportion of headwater streams fail to meet CWA goals in Ohio urban areas translates to the potential for undesirable

impacts in downstream waters and obvious consequences for the overall health of the “patient”.

There is concern that the attainment of CWA goal uses (e.g., warmwater habitat in Ohio) within small urban

watersheds may be precluded by the legacy of urbanization. If this is true, how is this determined and what are the

protection endpoints to guide water quality management? Federal water quality standards regulations (40CFR, Part 131)

33
allow for the establishment of a use that is less than the CWA fishable and swimmable goals when it is precluded by the

following:

1) the degraded conditions are naturally occurring;

2) restoring the degraded conditions would result in widespread adverse socioeconomic impacts;

3) the degraded conditions are irretrievable and human induced.

Such uses are established on a waterbody-specific basis and are supported by a use attainability analysis. In Ohio,

such analyses are routinely conducted as a result of the five-year basin approach to monitoring, assessment, and water

quality management. One purpose of this paper is to advance the development of the tools and indicators needed to

make use attainability decisions in urban watersheds.

Ohio EPA routinely conducts biological and water quality surveys, or “biosurveys”, on a systematic basis statewide.

A biosurvey is an interdisciplinary monitoring effort coordinated on a waterbody-specific or watershed scale. Such efforts

may be relatively simple, focusing on one or two small streams, one or two principal stressors, and a handful of sampling

sites; or much more complex, including entire drainage basins, multiple and overlapping stressors, and tens of sites. Each

year, Ohio EPA conducts biosurveys in 1 O-l 5 different study areas with an aggregate total of 350-450 sampling sites.

Biological, chemical, and physical monitoring and assessment techniques are employed in biosurveys in order to meet

three major objectives: 1) determine the extent to which use designations assigned in the Ohio Water Quality Standards

(WQS) are either attained or not attained; 2) determine if use designations assigned to a given water body are appropriate

and attainable; and 3) determine if any changes in key ambient biological, chemical, or physical indicators have taken

place over time, particularly before and after the implementation of point source pollution controls or best management

practices. The data gathered by a biosurvey is processed, evaluated, and synthesized in a biological and water quality

report. The findings and conclusions of each biological and water quality study may factor into regulatory actions taken

by Ohio EPA and are incorporated into Water Quality Permit Support Documents (WQPSDs), State Water Quality

Management Plans, the Ohio Nonpoint Source Assessment, and the Ohio Water Resource Inventory (305[b] Report).

In 1990, the Ohio EPA initiated an organized, sequential approach to monitoring and assessment, termed the FiveYear Basin Approach. One of the principal objectives of this new approach was to better coordinate the collection of

ambient monitoring data so that information and reports would be available in time to support water quality management

activities such as the reissuance of NPDES permits and periodic revision of the Ohio Water Quality Standards (WQS).

Ohio EPA’s approach to surface water monitoring and water quality management via the Five-Year Basin Approach

essentially serves as an environmental feedback process taking “cues” from environmental indicators to effect needed

changes or adjustments within water quality management. The environmental indicators used in this process are

categorized as stressor, exposure, and response indicators (Yoder and Rankin 1998). Stressor indicators generally

include activities that impact, but which may or may not degrade the environment. This includes point and nonpoint

source loadings, land use changes, and other broad-scale influences that generally result from anthropogenicactivities.

Exposure indicators include chemical-specific, whole effluent toxicity, tissue residues, and biomarkers, each of which

suggests or provides evidence of biological exposure to stressor agents. Responseindicators include the direct measures

of the status of use designations. For aquatic life uses, the community and population response parameters that are

represented by the biological indices that comprise Ohio EPA’s biological criteria are the principal response indicators.

Previously, our analyses examined the water quality and biological assessment database from watersheds in and

near existing and developing urban and suburban areas of Ohio. Yoder and Rankin (1997) compiled their analyses based

on sampling conducted at more than 100 stream sampling locations. Yoder et al. (1999) examined more detailed land

use and stressor relationships with the Index of Biotic Integrity (IBI), based on fish assemblage data, and the Invertebrate

Community Index (ICI), based on macroinvertebrate assemblage data, within two major Ohio urban areas

(Akron/Cleveland and Columbus). This study consisted of a quantitative analysis of the relationship between the IBI, an

indicator of urban land use, and a qualitative analysis of other stressors influencing this relationship using available data

from all six of the major metropolitan areas within Ohio. The importance of understanding these relationships is

heightened by contemporary water quality management issues such as combined sewers and stormwater permitting.

One challenge we faced was in attempting to separate the influences of these multiple stressors on aquatic life attainment

34
status. Could we sufficiently understand the baseline influence of urbanization apart from these other and better

understood stressors?

The principal analysis conducted in this study examined the relationship between urban land cover and the IBI, both

visually and by statistical analysis. Some goals were to determine the extent to which biological performance (as

expressed by the IBI) was correlated with urban land use, thresholds at which this occurred, and the overlying effects of

other stressors.

Met hods

A database consisting of 267 sampling locations from the six major metropolitan areas of Ohio was extracted from

the Ohio EPA statewide biological and habitat database. Most of these sites were sampled between 1990 and 1998 and

contained watershed areas less than 50 mi.2, with most draining less than 20 mi .2. As such, the database represents a

collection of discrete watershed units where land uses may have a significant effect on the composition and quality of the

instream habitat and biological communities. Urban land use effects have been much more apparent in these smaller

watersheds as evidenced by the higher proportion of impaired stream miles compared to larger streams and rivers in Ohio

(Yoder 1995; Yoder and Rankin 1997).

Fish communities were sampled using generator-powered, pulsed D.C. electrofishing units and a standardized

methodology (Ohio EPA 1987a,b, 1989a,b; Yoder and Smith 1999). Fish community attributes were collectively

expressed by the Index of Biotic Integrity (IBI; Karr 1981; Karr et al. 1986), as modified for Ohio streams and rivers (Yoder

and Rankin 1995; Ohio EPA 1987b, 1989b). Habitat was assessed at all fish sampling locations using the Qualitative

Habitat Evaluation Index (QHEI; Rankin 1989, 1995). The QHEI is a qualitative, visual assessment of the functional

aspects of stream macrohabitats (e.g., amount and type of cover, substrate quality and condition, riparian quality and

width, siltation, channel morphology, etc.). Ohio EPA also collected macroinvertebrate assemblage data at some of these

sites, but it was not included in this study because of the partial coverage and the extensive use of the qualitative method

was not always compatible with regression analysis. Some of the analyses in our earlier studies (Yoder et al. 1999)

included macroinvertebrate data.

The urban land use indicator was derived from Landsat Thematic Mapper satellite imagery of land cover classification

(September 1994) provided by the Ohio Department of Natural Resources. The percentage of land use in the urban

classification was calculated for the subwatershed upstream from each fish sampling location to the boundary of the

watershed. Because many of the sites included in the statewide data set are subjected to a variety of stressors, each

site was qualitatively classified by predominant impact type. Impact types included least impacted sites, estate sites (i.e.,

subwatersheds with large lot sizes or green space provided by parks), sites reflecting gross instream habitat alterations

(i.e., channel modifications or impoundment), sites impacted directly by discharges from combined sewer overflows

(CSOs), sites impacted by wastewater treatment plant discharges, sites impacted by instream sewer line placement and

construction (Cincinnati area only), sites with evidence of impacts by legacy pollutants, or sites affected by general

urbanization only. This latter category included urban land uses not containing any of the other impact types and usually

consisted of residential development.

Results

The relationship between the IBI and urban land use was initially characterized by regressing IBI scores against

percent urban land use (log,, transformed) and QHEI scores using a database of 267 sites for all of the six major

metropolitan areas of Ohio (Figure 1). Diagnostic plots (e.g., residuals, normal probability) indicated nonconstancyof error

variance. To provide insights into whether the results varied substantially between each metropolitan area, scatter plots

of the relationship between urban land use and IBI in each of the six metro areas were also made (Figure 2). A negative

relationship between IBI and urban land use was observed in four of the six areas, whereas little or no relationship was

seen in two areas. For each area, the highest percentage of urban land use that corresponded to minimum attainment

of the WWH IBI biocriterion was determined by inspection of the scatter plot and the intersection of the regression line

and the WWH IBI biocriterion were determined (Figure 2). This ranged from 1% (Cleveland/Akron) to 12% (Dayton) for

the regression line, and 15% (Cleveland/Akron) to 58% (Columbus) as the highest %urban land use where WWH was

attained in each area at a given sampling location. No significant linear relationship was found in either the Toledo or

35
IMPACT TYPES

,

0 Habitat

q Background

q Urban

0 WWTP

- + Legacy

A cso/sso

q Estate

v Sewer Line

6 0

=

m

= 50

E

ii!

0

If 4 0

m

;;

X 20

W

EWH Biocriterion

Ed

(ml = 50

0

‘I m

-- - WWH

I - D

Biocriterion

,- /(/B/ = 40)

AA A

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0

Percent Urban Landuse

Figure 1. Scatter plot of Index of Biotic Integrity (IBI) scores against percentage of watershed upstream from the site in urban land use at 267 small (~50

mi.‘) sampling sites.

Youngstown areas, and only a weak relationship was visually apparent for the Toledo streams. All of the sites in the

Youngstown area were impaired, and so severely that no land use relationship was evident (Figure 2). In the Toledo area,

the highest urban land use corresponding to WWH attainment was 28%. However, the WWH IBI biocriterion in the

Huron/Erie Lake Plain ecoregion is the lowest in the state and almost all of the small streams in the Toledo area have

been channel modified to some degree. It was apparent that the lack of a stronger association between IBI and urban

land use was due to overlying stressors (e.g., legacy pollutants, WWTPs, CSOs/SSOs), particularly those that resulted

in very low IBI values at sites with low levels of urbanization. While some threshold relationships were evident in these

results, the resulting variability in IBI scores led to only weak or non-existent linear relationships.

Some of the impact types had a strong effect on the IBI regardless of the effect of urban land use. The IBI results

were examined by impact type across all six metro areas (Figure 3). The legacy, CSOKSO, habitat, and WWTP impact

types had the strongest negative effects on the IBI, respectively, and this was independent of the urban land use indicator.

While these impact types are common to urban areas, they were removed from the remaining statistical analyses

(elimination of these impact types reduced the sample size to 123 sites) to better develop the IBVurban land use

relationship. The entire Toledo and Youngstown datasets were also removed since they are comprised entirely of these

impact types. This resulted in a better regression model fit, and diagnostics consistent with regression model assumptions

(Neter et al. 1990). This also allowed us to discern the threshold of urbanization at which WWH attainment is lost with

greater precision and in the absence of potentially confounding impacts, which was a major objective of our study. The

relationship between different levels of urbanization and biotic integrity was further quantified with an analysis of variance

model where quartiles of percent urban land use determined factor level (e.g., all sites within the 1 st quartile of percent

urban land use were coded as factor level 1). Similarly, an analysis of covariance model using QHEI as the covariate

was employed to test for further refinements. Multiple comparisons of factor level mean differences were made using

Tukey’s method (Neter et al., 1990).

36
60

4 0

IBI

3 0

2 0

10

Maximum Observed

Repression Line %“rban That

Intersects Intersects w w H Meets WWH

(11%) (27%)

r

- Cincinnati Area &ream4

I+ +

+ I I

i lb 100

Percent Urban Landuse

Maximum Observed

Regression Line %Urban That

Intersect9 WWH Meets WWH

11 I+ f +-

1 0 II II 1.1111, II II """I 33 . v..ml

0.1 1 10 100

Percent Urban Landuse

Maximum Observed

%Urban That

MeeLS WWH

(28%)

60 :

II _

: Toledo Area Streams I _I _

50 : II _

, _

II _

40 -

II -

t

0.1 1 1 0 100

Percent Urban Landuse

6 0

4 0

IBI

30

20

Maximum Observed

Regression Line %Urban That

Intersects W W H Meets WWH

10’

0.1 1 10 100

Percent Urban Landuse

Maximum Observed

Regressmn Line %Urban That

Intersect5 WWH Meets WWH

6 0

2 0

1 0

1 10 100

Percent U rban Landuse

Maximum Observed

%Urban That

Mae& WWH

60 L

(0%)

. I

Youngstown AreaStreams

4 0

IBI

lo l-o

Percent Urban Landuse

Figure 2. Scatter plots of Index of Biotic Integrity (IBI) scores against percentage of watershed upstream from the site in urban land use at small stream

(-30 mi.‘) sampling sites in six of the major metropolitan areas of Ohio. Predominant impact types are indicated for each site (see Figure 1) along with the

regression line. The warmwater habitat and exceptional warmwater habitat biological criteria for the IBI are also indicated.

37
60

40

IBI

30

20

12

60

50

40

IBI

30

20

12

,ll/lll,l//,llllllIlll/lllllllllllllllI_

I Maximum %Urban

I That Meets WWH

cqo - 0 00 0 0 0

,,,,,I I,I/,III~/II,,/I,I~IIII,III,~IIII

0 10 20 30 40 50 60 70 80

Percent Urban Landuse

022.6 I Maximum %Urban

I

30.2@8.4

Tt-at Meets WWH

0

(excluding outliers)

5%

omch ;

0 _ /019.8

U

-Avg. Age = 28.2

-Med. Age = 28.5

I0

cl

I

I 0

,,,,,,,I ‘,,,“~1”‘,‘“1~‘“1,1”,~“”

0 10 20 30 40 50 60 70 80

Percent Urban Landuse

Figure 3. Box-and-whisker plots of Index of Biotic Integrity (IEN) scores by each of the major impact types used in Figures 1 and 2. The warmwater

habitat and exceptional warmwater habitat biological criteria for the IBI are indicated.

38
The percentage of urban land use explained approximately 35% of the variation in IBI scores in the regression model

when the other impact types were excluded. Local habitat quality (as measured by the QHEI) explained an additional

7% of the variation (Table 1). The ANOVA model showed that there were significant differences in mean IBI scores

between quartile level of percent urbanization, with sites exceeding 29 % urban land cover having lower IBI scores on

average than sites with less urban land cover (Figure 4). Sites characterized by less than 4% urban land cover had

higher IBI scores than sites with urban land use exceeding 15% The ANCOVA model provided a slightly better fit, but

the additional variation explained was marginal (Table 2), and the results of pairwise comparisons were similar between

models (Figure 4).

Table 1. Regression Results for the Model Ibl = Log,,(Percent Urban Land Use+l)+qhei for All Sites and the Removal of Selected Impact Types.

Effect

A// Sites

CONSTANT

Urban

QHEI

Coefficient SE t P(2 Tail)

21.9333 2.9450 7.4477 0.0000

-6.8323 1.1370 -6.0092 0.0000

0.2676 0.0418 6.4102 0.0001

Adj. R-Squared

0.1179

0.2388

Impact Types Removed

CONSTANT

Urban

QHEI

32.4069 4.2184 7.6822 0.0000

-11.1496 1.3102 -8.5096 0.0000 0.3500

0.2390 0.0605 3.9493 0.0001 0.4199

Figure 4. Distributions of Index of Biotic Integrity (IBI) from small streams (~50 mi.*) in the six major metropolitan areas of Ohio plotted by quartiles of

percent of urbanization upstream from sampling locations. Horizontal lines spanning adjacent box plots indicate similar means. Levels of percent of

urbanization corresponding to the 25th, 50th and 75th percentile are indicated. The shaded areas indicate the applicable warmwater habitat biological

criterion and the range of insignificant departure for the IBI.

39
Table 2. Analysis of Variance Results for the Anova Model, and the Ancova Model Using Qhei as a Covariate.

ANOVA

Source Sum-of-Squares df Mean-Square F-ratio P R-Squared

Urban 4248.53 3 1416.18 27.50 0.0000 0.4094

Error 6129.10 119 51.51

ANCOVA

Source Sum-of-Squares df Mean-Square F-ratio P

Urban 4020.66 3 1340.22 28.81 0.0000

QHEI 640.71 1 640.71 13.78 0.0003 0.4711

Error 5488.39 118 46.51

In an attempt to better visualize where attainment of warmwater habitat occurs along the urban land use gradient,

the IBI results were plotted against percent of urban land use for all sites used in this study and with the other impact

types excluded (Figure 5). The elimination of the other impact types provided for a more precise statistical relationship

between urban land use and the IBI (i.e., lower error of regression estimates). For example, the R* was higher with the

removal of the other impact types and the slope of the regression was steeper, both of which suggest a more meaningful

relationship between the IBI and urban land use (Table 1). However, the percent of urban land use that corresponded

to attainment of the warmwater habitat IBI biocriterion based on inspection of the scatter plot was the same

(approximately 26%) in both plots.

W W H Biocriteria

4 0

m3 0

20

10

1 st 2nd 3rd 4th

~4.2% 4.3-l 4.6% 14.7-29.3% >29.3%

Quartile Level of Percent Urbanization

Figure 5. Scatter plots of Index of Biotic Integrity (IBI) scores against percentage of watershed upstream from the site in urban land use at small stream

(~50 mi.*) sampling sites in six of the major metropolitan areas of Ohio for all sites (upper) and a subset with non-urban impact types removed (lower). The

age of the urbanized area is indicated for selected sites and the mean and median age for entire dataset. The warmwater habitat biological criterion and

the range of insignificant departure for the IBI are indicated.

40
Also apparent in both plots was the occurrence of “outliers”where IBI scores above the warmwater habitat biocriterion

occurred at sites with 40% to 60% urban land use. These sites had either an intact, wooded riparian zone, a continuous

influx of groundwater, and/or the relatively recent onset of urbanization. Intact riparian buffers can mitigate the effects

of urban land use up to a point (Steedman 1988; Horner et al. 1997) and local hydrology can strongly influence the quality

of the fish assemblage (Poff and Allen 1995). The three sites with the relatively recent onset of urbanization (all ~20

years) may not yet have accrued the types of negative effects that are readily apparent in some of the older urbanized

areas of Ohio.

Discussion

Threshold levels of urbanization beyond which biological communities are likelyto be impaired have previously been

identified in the range of 8% to 20% impervious cover within a watershed (Schuler 1994). Our previous analyses (Yoder

et al. 1999) produced results of approximately 8% and 33% urban land use cover for the Cuyahoga River basin and

Columbus area streams, as identified by analysis of variance. We also concluded that the threshold level identified by

regression for the Cuyahoga River basin was lowered by the presence of other stressors (e.g., CSOs, point sources,

legacy pollutants). The elimination of those sites impacted by these other stressorsfrom the regression analysis resulted

in a higher threshold of urbanization. Our expanded study seemed to confirm this phenomenon, as the elimination of the

other impact types helped clarify the urban land use/lBI relationship in a broader array of urban influenced streams

throughout Ohio (Figure 5). The upper threshold of urbanization which corresponded to a loss of warmwater habitat

attainment was in the 25-30% range. However, our results show that non-attainment also occurs at lower thresholds of

urbanization (Figure 5) due primarily to the co-occurrence of other stressors. This makes both the linear and visual

derivation of sufficiently precise indicator thresholds such as percentage of impervious surfaces more difficult.

In terms of understanding the potential effect of urbanization on aquatic life use attainment, the most meaningful

results of our analyses are the upper thresholds at which attainment of CWA goal uses are mostly lost (e.g., 25%) and

that beyond which it never occurs (>60%). Only a very few sites exhibited full attainment of the warmwater habitat

biocriteria at urban land uses between 40-60% (Figure 5). A closer examination of these sites and the watersheds

showed the presence of high quality riparian zones, an influx of flow augmenting groundwater, and/or development of the

urban land use occurring within the past 20 years. For the latter, we hypothesized that the full effect of negative impacts

in an urban setting may take time to accumulate and may not be immediately manifest in the form of instream

impairments. This could account for the higher-than-expected urban land use (i.e., 40-60%) correlating with full

attainment of the biocriteria. If this is true, then we might expect these sites to exhibit declines in IBI scores over the next

one or two decades. It also suggests that newly urbanizing watersheds should be developed with an emphasis on

determining which attributes (e.g., riparian zones, wetlands, flow regime) need to be maintained and preserved in order

to protect and maintain instream habitat and biological quality.

The results of this study indicate that it might be possible to partially mitigate the negative effects of urbanization by

preserving or enhancing near and instream habitats, particularly the quality of the riparian buffer zone. The “outlier” sites

that exhibited full attainment of the warmwater habitat biocriteria had more extensive and higher quality riparian zones

and good to excellent instream habitat quality. Some streams were nestled in small valleys which were not amenable

to development and the accompanying encroachment of urban land uses. This generally agrees with the findings of

Steedman (1988) who demonstrated a co-relationship between riparian zone quality and land use in terms of how each

affected the fish communities and IBI values of Toronto area streams. Horner et al. (1997) also found that the negative

effects of urban land use were mitigated by riparian protection and other management interventions. However, in both

studies the quality and extent of the riparian zone ceased to be effective above 45-60% impervious land cover, which

generally corresponds to the thresholds identified by our study. Until we better understand the effect of the “age” of the

urban effect, it seems prudent to advocate policies that preserve existing riparian zones rather than responding with posturbanization retrofits.

Yoder et al. (1999) discussed the implications of their findings on the designation of aquatic life uses in state water

quality standards, particularly to the use attainability analysis process. Uses designated for specific water bodies are done

so with the expectation that the criteria associated with the use are reasonably attainable. If CWA goal uses (e.g.,

warmwater habitat in Ohio) are found to be unattainable, then lower quality uses may be established and assigned on

a case-by-case basis (40CFR, Part 131 .lO[g]). Recently, the imperviousness of the watershed has been suggested as

41
an indicator that is correlated with use attainability. If the frequently cited threshold of 25% impermeability is used,

streams in watersheds with greater than this value could be considered unlikely to ever attain a beneficial use regardless

of site- and reach-specific factors. This assumes that the negative effects of urbanization cannot be remediated, which

has yet to be extensively tested. However, the results of our study suggest that there is a threshold of watershed

urbanization (e.g., >60%) beyond which attainment of the WWH use becomes increasingly unlikely, at least as affected

by contemporary practices. This threshold is not the same in all watersheds, as evidenced by the results from the six

Ohio metropolitan areas, and it can occupy a rather wide range. In addition, co-factors such as pollutant loadings,

watershed development history, chemical stressors, and watershed scale influences such as the quality of the riparian

buffer and the mosaic of different types of land use, also act singly and in combination to determine to the resultant

biological quality in the receiving streams. Thus, single dimensional urban land use indicators, such as watershed

imperviousness, is not sufficiently precise or reliable as a single indicator of use attainability.

The further development and refinement of multiple indicators of watershed urbanization has merit from a

management and decision-making standpoint. Because of the many co-factors involved (e.g., water quality, habitat

quality, hydrologic regime, etc.), some of which are controllable and amenable to reasonable remediation, this will be a

complex undertaking. We suggest that these co-factors, in addition to more refined urban land use indicators, be

developed and tested using datasets from broad geographic areas spanning the extremes of the urbanization gradient.

Urban land use and its analogs (e.g., % imperviousness) are coarse approximations of the cumulative effect of all

negative influences within a watershed. Thus co-factors and more precise definitions of different urban land uses need

to be defined in order to better understand and respond to the water quality management challenges posed in existing

and developing urban areas.

A management outgrowth of such an effort could be the development of an urban stream habitat use designation.

Yoder et al. (1999) previously indicated where the biological criteria for this potential new use designation might occur

compared to the already existing hierarchy of aquatic life uses in the Ohio WQS (Figure 6). This designated use would

Quality Gradient of Aquatic Life Uses and Narrative

Descriptions of Biological Community Condition

Max.

I

Exceptional

Warmwater

Warmwater

Habitat (WWH)

LOW BIOLOGICAL IM-EGRIT- HIGH

Figure 6. Relationship between the tiered aquatic life uses in the Ohio WQS and narrative evaluations of biological community performance and how this

corresponds to a qualitative scale of biological integrity and of the biological indices that comprise the Ohio biological criteria. The position of a potential

new Urban Stream Habitat (USH) use designation is indicated (after Yoder et al. 1999).

42
satisfy the desire to afford urban streams the maximum protection practicable, while recognizing the inherent limitations

that the irretrievable effects of urbanization may impose on stream quality. In the meantime, simplistic regulatory and

management approaches should be avoided, particularly in those watersheds where uncertainty about the attainability

of CWA goal uses (i.e., WWH and higher) exists. For example, a single indicator of urban development (e.g., proportion

of impermeable surfaces) is alone insufficient to drive this process. We envision that more refined, multiple indicators

of urban development will provide the necessary sophistication to more appropriately define when this less than CWA

goal use should be applied. In the meantime, management strategies such as the nine minimum controls for CSOs seem

reasonable analogies for the management of urban watersheds and stormwater runoff. However, proceeding beyond

such minimum requirements with long-term remediation plans should be done with deference to the use attainability

issues and with the aid of sufficiently robust before-and-after biological and water quality assessments.

References

Horner, R.R., D.B. Booth, A. Azous, and C.W. May. 1997. Watershed determinants of ecosystem functioning, pp. 251-

274. In C. Roesner (ed.). Effects of Watershed Development and Management on Aquatic Ecosystems, American

Society of Civil Engineers, New York, NY.

Karr, J. R. 1981. Assessment of biotic integrity using fish communities. Fisheries 6(6): 21-27.

Karr, J. R., K. D. Fausch, P. L. Angermier, P. R. Yant, and I. J. Schlosser. 1986. Assessing biological integrity in running

waters: a method and its rationale. Illinois Natural History Survey Special Publication 5: 28 pp.

Neter J., Wasserman W., and Kutner M. H. 1990. Applied Linear Statistical Models: Regression, Analysis of Variance,

and Experimental Designs. Irwin, Homewood, Illinois.

Ohio Environmental Protection Agency. 1998. 1998 Ohio water resource inventory - volume I addendum, summary,

status, and trends. Rankin, E.T., Yoder, C.O., and Mishne, D.A. (eds.), Ohio EPA Tech. Bull. MAS/1998-6-1, Division

of Surface Water, Columbus, Ohio. 190 pp.

Ohio Environmental Protection Agency. 1990. Ohio’s nonpoint source pollution assessment. Division of Water Quality

Planning and Assessment.. Columbus, Ohio.

Ohio Environmental Protection Agency. 1991. 1991 Ohio nonpoint source assessment. Ohio EPA. Division of Water

Quality Planning and Assessment.. Columbus, Ohio.

Ohio Environmental Protection Agency. 1989a. Biological criteria for the protection of aquatic life. volume III:

standardized biological field sampling and laboratory methods for assessing fish and macroinvertebrate communities,

Division of Water Quality Monitoring and Assessment, Columbus, Ohio.

Ohio Environmental Protection Agency. 1989b. Addendum to biological criteria for the protection of aquatic life. volume

II: users manual for biological field assessment of Ohio surface waters, Division of Water Quality Planning and

Assessment, Surface Water Section, Columbus, Ohio.

Ohio Environmental Protection Agency. 1987a. Biological criteria for the protection of aquatic life: Volume I. The role

of biological data in water quality assessment. Division of Water Quality Monitoring and Assessment, Surface Water

Section, Columbus, Ohio.

Ohio Environmental Protection Agency. 1987b. Biological criteria for the protection of aquatic life: volume II. users

manual for biological field assessment of Ohio surface waters, Division of Water Quality Monitoring and Assessment,

Surface Water Section, Columbus, Ohio.

Poff, N.L. And J.D. Allen. 1995. Functional organization of stream fish assemblages in relation to hydrological variability.

Ecology 76(2): 606-627.

43
Rankin, E. T. 1995. The use of habitat assessments in water resource management programs, pp. 181-208. in W. Davis

and T. Simon (eds.). Biological Assessment and Criteria: Tools for Water Resource Planning and Decision Making.

Lewis Publishers, Boca Raton, FL.

Rankin, E. T. 1989. The qualitative habitat evaluation index (QHEI), rationale, methods, and application, Ohio EPA,

Division of Water Quality Planning and Assessment, Ecological Assessment Section, Columbus, Ohio.

Schuler, T. R. 1994. The importance of imperviousness. Watershed Protection Techniques I : 100 - 111.

Steedman, R.J. 1988. Modification and assessment of an index of biotic integrity to quantify stream quality in southern

Ontario. Can. J. Fish. Aq. Sci. 45: 492-501.

Yoder, C.O. 1995. Incorporating ecological concepts and biological criteria in the assessment and management of urban

nonpoint source pollution, pp. 183-197. in D. Murray (ed.). National Conference on Urban Runoff Management:

Enhancing Urban Watershed Management at the Local, County, and State Levels. EPA/625/R-95/003.

Yoder, C.O. and E.T. Rankin. 1998. The role of biological indicators in a state water quality management process. J.

Env. Mon. Assess. 51(1-2): 61-88.

Yoder, C.O. and E.T. Rankin. 1997. Assessing the condition and status of aquatic life designated uses in urban and

suburban watersheds, pp. 201-227. in Roesner, L.A. (ed.). Effects of Watershed Development and Management on

Aquatic Ecosystems, American Society of Civil Engineers, New York, NY.

Yoder, C.O. and E.T. Rankin. 1995. Biological criteria program development and implementation in Ohio, pp. 109-144.

in W. Davis and T. Simon (eds.). Biological Assessment and Criteria: Tools for Water Resource Planning and Decision

Making. Lewis Publishers, Boca Raton, FL.

Yoder, C.O. and M.A. Smith. 1999. Using fish assemblages in a state biological assessment and criteria program:

essential concepts and considerations, pp. 17-56. in T. Simon (ed.). Assessing the Sustainability and Biological Integrity

of Water Resources Using Fish Communities. CRC Press, Boca Raton, FL.

Yoder, C.O., Miltner, R.J., and D. White. 1999. Assessing the status of aquatic life designated uses in urban and

suburban watersheds, pp. 16-28. in Everson, A. et al. (eds.). National Conference on Retrofit Opportunities for Water

Resource Protection in Urban Environments, Chicago, IL. EPA/625/R-99/002.

44
Getting Past the Obvious

Robbin B. Sotir, President

Robbin B. Sotir & Associates, Inc.

Marietta, GA 30064

Abstract

Long Leaf Creek is located within an urbanized watershed along coastal North Carolina. The specific stream reach

addressed is located in a residential subdivision. Conditions had dramatically changed there due to the continued

development of the watershed. The stream had deepened and widened as result of increased runoff and high

concentration events, including hurricanes. This increased the loss of aesthetic value, riparian corridor vegetation, and

aquatic and terrestrial habitats. Water quality was also degraded.

Before they could decide how best to control flooding and stabilize and restore Long Leaf Creek to a naturally

functioning channel within its changed watershed conditions, citizens had to be educated about natural stabilization and

restoration technologies and specificmethods that would work, including conventional options. Soil bioengineering was

agreed upon, with numerous modifications to meet specific needs.

This paper is presented from both the client’s and consultant’s perspectives. It identifies what worked, what did not

work, and what was necessary to improve the process for successful, long-term results. We present the lessons learned

from criteria issue development and understanding, educational process alternatives preparation, design, construction,

and project results since construction.

Paper

Long Leaf Creek is located within an urbanized watershed along coastal North Carolina. The specific stream reach

addressed is approximately 2000 feet in length and is located in a residential subdivision. It is a highly sensitive project

with a variety of multi-objective goals specific to its location and function and typical to urbanizing areas. The watershed

includes residential, office, institutional, and commercial properties, including 25 homes that line the creek in this area.

Residents living along the creek described the former Long Leaf, as a small, picturesque stream that pleasantly flowed

through their neighborhood--a stream that could be jumped across. It was enjoyed by many people. The conditions had

dramatically changed, however, due to the continued development of the watershed, especially a new road and large

shopping center immediately upstream. Residents have seen their stream deepen by almost ten feet and widen by 40

feet in areas, a result of increased runoff and high concentration events, including hurricanes. In many areas, the banks

were vertical. Large, woody debris filled much of the channel, and many people were now using the “ditch” as a yard and

construction waste dump (see Figure 1). This has resulted in increased the loss of aesthetic value, riparian corridor

vegetation, and aquatic and terrestrial habitats. Water quality has also been degraded.

Many people had already lost property due to stream widening and were unwilling to lose more. Flooding was a major

problem in the downstream end, while erosion was occurring throughout the project reach. The City of Wilmington was

interested in exploring a natural approach to solving the problem. After assessing the site and conditions, and listening

to the residents= concerns and desired solutions, it was clear that a strong, continual working relationship had to be

formed with the neighborhood to ensure project success.

45
Figure 1. Pre-Construction Conditions

46
Before they could decide how best to control flooding and stabilize and restore Long Leaf Creek to a naturally

functioning channel within its changed watershed conditions, citizens had to be educated about natural stabilization and

restoration technologies and the specific methods that would work, including comparative conventional options. To “get

past the obvious,” it was clear that almost everyone would have to give up some land and existing trees to solve their

continued land loss and flooding problems and to improve the environmental and aesthetic values of Long Leaf Creek.

How much land and how many trees they would lose would ultimately depend on their selected restoration alternative.

A matrix was developed using critical issues and matching these to possible alternatives (Table 1). Soil bioengineering

was agreed upon, with numerous modifications to meet specific needs.

Robbin B. Sotir & Associates, Inc., (RBSA), served as the soil bioengineering consultant to the prime, the KimleyHorn’s interdisciplinary team, developed the geotechnical design and hydraulic eff iciencies of a soil bioengineering solution

to address the desired goals and critical engineering, environmental, and aesthetic issues.

Alternatives were compared with such critical issues as erosion control, streambank stabilization, safer and healthier

environment, flood control, timely project completion, environmental and aesthetic improvement, property loss

minimization, hydraulic efficiency, and cost feasibility.

After an initial investigation, an alternative analysis was produced in the summer of 1997. This alternative analysis

explored numerous approaches to solving each of the project goals, with cost and risk factors assigned to each

alternative. Several alternatives were considered, such as box culverts, 3:l (horizontal : vertical) grassed slopes, 2:l

riprap rock, 2:l concrete lining, and soil bioengineered slope systems. With input from the residents and permit

authorities, the City selected the soil bioengineering approach and commissioned a design team to produce plan and

specification documents, including construction cost estimates.

The selected systems employed the use of live fascines, brushlayer/live fascines, joint planting and vegetated

geogrids (see Figures 2 through 5).

The majority of the improvement was done using vegetated geogrid, due to its soil reinforcing capabilities and ability

to reduce land losses (see Figure 6).

Pre-bid, preconstruction, and permit application services were provided to support the project. Construction was

completed by the spring of 1999.

The project has performed well from a biological perspective. Willow, baccharis, and myrtle installed as cuttings in

the lower layer had a survival rate of approximately 80%. The rooted stock installed in the upper two layers comprised

of spirea bush, Carolina allspice, serviceberry, and viburnum, were less successful, with a survival rate of approximately

60% due to an insect infestation (see Figure 7). Hydraulically, we have had some bed scour, accompanied by toe

erosion.

The survival rate of the rooted stock would have been higher had the watering maintenance program been followed.

It is also possible that the insect infestation would not have occurred if the plants had been kept healthier by better

maintenance practices. The rooted plants will be replaced by the contractor under the maintenance agreement. The

contractor is also responsible for taking care of the insect infestation. The bed scour in the upper level caused by

Hurricane Floyd is being handled with check dams to stop the bank from lowering and to control the toe scour.

47
Table 1. Long Leaf Hills/Hewletts Creek Alternatives and Critical Issues

Alternatives

Critical

Issues

Stop Erosion

& Stabilize

Banks

Intermediate

Action

39 Side Slopes 2:l Side Slopes 29 Side Slopes Reinforced Soil

Grass Lining’ Riprap Rock’ with Concrete Lining* Box Concrete Bioengineering

0 0 0 n/a l

Clean Out

Trash &

Debris, Remove

Fallen Trees

0 0 l 0 a a

Safer &

Healthier

Area

Control

Flooding

Timely

Project

Completion

Environmental

Improvement

Aesthetically

Enhancing

Meets Hydraulic 0

COE and

Environmental

Permits

Approval

Probability

l

0

0

0

l

0

n/a

n/a

0

0

0

0

0

0

0

Minimize

Property

Loss

0 0 0

Preliminary $250,000 $640,000 $900,000 $785,000

Cost Estimate

Range $40;000 $6ab9000 $1,4~,000 $1,2&000

‘Does not address geotechnical issues of sandy bank material stability and major land loss requirements.

*Does not address increased safety concerns or reduction in property values.

$1,750,000 $1 ,ooo,ooo

$2,3~,000 $1 &ooo

48
LIVECUT

BRANCHES

Figure 2. Live Fascine.

LM3FAscINB

EXCAVATEDTERRACEI I

Figure 3. BrushlayeriLive Fascine.

49
Figure 4. Joint Planting.

LIVEBRANCHES -

mV-

-

= *4

-- ,.

Figure 5. Vegetated Geogri

50
Figure 6. During Construction.

Figure 7. Three Months After Construction.
The project is functioning well from the bank stability and flood control aspects and the stream is operating within the

parameters of the new watershed conditions. It is aesthetically attractive and, over time, should develop some ecological

diversity. In summary, it is clear that the soil bioengineering approach is succeeding. The most important lessons learned

were as follows:

l Learn more about the bed conditions in areas that have had high deposits of mobile materials

l Employ sophisticated grade control structures

l Ensure installation procedures are followed correctly and that materials are not changed

l Keep tabs on the contractor’s maintenance schedule

l There is no substitute for communication and cooperation

Reference

Sotir, R.B.; “Brushing Up On Erosion,” American Cities and Counties, February, 1998.

52
Protecting and Enhancing Urban Waters:

Using All the Tools Successfully

Eric H. Livingston

Stormwater/NPS Management Section

Florida Department of Environmental Protection

Tallahassee, Florida 32399-2400

Abstract

Reducing the hydrologic effects and pollutant loadings from urban drainage systems and restoring aquatic habitats

to improve the health of our aquatic ecosystems presents many unique challenges. These challenges can be categorized

as technical, institutional, financial, and cultural. This paper will examine each of the challenges and the tools that have

and are being developed to overcome them. A case study on how the tools are being used in Florida to enhance the

health of the Tampa Bay aquatic ecosystem will be presented.

Introduction

Research conducted in Florida during the late 1970s characterized stormwater pollutants, provided cost and benefit

information on many types of stormwater treatment practices, and determined the importance of stormwater discharges

as a major source of pollution. As a result, in 1979, the Florida Environmental Regulation Commission adopted the state’s

first stormwater treatment requirements. In 1982, the state’s stormwater rule was fully adopted, requiring all new

development and redevelopment projects to include site appropriate BMPs to treat stormwater. This technology-based

program establishes a performance standard of removing at least 80% of the average annual post-development loading

of total suspended solids for stormwater discharged to most waters. Stormwater discharges to the state’s most pristine

waters, known as Outstanding Florida Waters, are required to reduce pollutant loading by 95%.

Florida’s stormwater treatment program, in combination with the state’s wetlands protection, land acquisition, and

growth management programs, has greatly minimized the effects of Florida’s rapid growth on its water bodies. However,

land uses and hydrologic alterations that occurred before the mid-l 980s has continued to adversely affect the state’s

vulnerable and valuable aquatic ecosystems. Accordingly, the focus of Florida’s watershed management program shifted

to cleaning up “older sources” such as existing land uses, whether urban or agricultural, and to integrating program

components to eliminate duplication and improve efficiency and effectiveness. This has led to greater emphasis on more

holistic approaches to address cumulative effects of land use activities within a watershed and to a greater emphasis on

regional structural controls and the purchase or restoration of environmentally sensitive lands. The key institutional

components of this watershed approach have been described in detail (WMI, 1997; Livingston et al., 1995).

Development of Florida’s Watershed Assessment Tools

Florida’s Water Implementation Rule, Chapter 62-40, F.A.C., establishes a performance standard for reducing, on

a watershed basis, the pollutant loading from older stormwater systems. The goal is to protect, maintain or restore the

beneficial uses of the receiving water body. The amount of needed pollutant load reduction is known as a “Pollutant Load

Reduction Goal or PLRG”. The rule further specifies that PLRGs be established as part of the states’s priority watershed

program, Surface Water Improvement and Management (SWIM), which is implemented by the state’s five water

management districts. Consequently, stormwater PLRGs have been established for several water bodies leading to the

development and implementation of watershed plans to reduce pollutants from urban and agricultural stormwater

discharges. For example, farms within the Everglades Agricultural Area have implemented BMPs to reduce phosphorus

loadings by 40%. Additionally, the federal and state government, SFWMD, and landowners within the EAA are sharing

the cost of constructing tens of thousands of acres of wetlands (Stormwater Treatment Areas) to provide for additional

reduction of phosphorus.

53
Having a sound institutional framework, however, is only one of the tools needed to successfully reduce stormwater

pollutant loadings from existing land uses. Equally important are funding and public education to promote the cultural

change necessary to reduce “Pointless Personal Pollution”. A final cornerstone is good science -to establish ecologically

meaningful watershed management goals, evaluate the effectiveness of BMPs and management programs, and assess

the cumulative effects of wet weather discharges.

Unlike traditional point sources of pollution, the effluent quality and environmental effects of stormwater and other

nonpoint sources of pollution are highly variable because of their intermittent, diffuse, land use-specific nature. Of

particular environmental concern is the cumulative impact on a water body from the numerous stormwater/nonpoint

sources within a watershed. Consequently, traditional water quality monitoring and management efforts used for point

discharges generally suffer from several deficiencies when trying to understand and manage stormwater/NPS pollution.

These deficiencies include difficulty in:

1. Assessing intermittent, shock loadings of pollutants.

2. Assessing cumulative impacts of multiple sources.

3. Comparing water bodies and establishing priorities for management actions.

4. Assessing hydrologic, geomorphological, and habitat alterations within a watershed.

5. Distinguishing actual or potential problems from perceived problems.

6. Discriminating anthropogenic loadings from natural watershed loadings of metals and nutrients.

7. Establishing cost-effective ways to assess pollution sources and trends on a watershed basis.

To overcome these problems, the Florida Department of Environmental Protection (DEP) has developed cost-effective

sediment and biological monitoring tools that are much better suited for assessing cumulative effects than traditional water

chemistry monitoring (Livingston et. al, 1995; McCarron et al., 1997). Most stormwater pollutants accumulate over time

in sediments, not the water column. Therefore, the sediments and the organisms that reside in them offer an in-situ

monitoring opportunity to determine the cumulative effects of watershed stormwater/NPS pollution sources on aquatic

systems or to evaluate the effectiveness of management programs.

Sediment quality is a sensitive indicator of overall environmental quality. Sediments influence the environmental fate

of many toxic and bioaccumulative substances in aquatic ecosystems (Long and Morgan, 1990). Sediments tend to

integrate contaminant concentrations over time and may represent long-term sources of contamination. Specifically,

sediment quality is important because many toxic contaminants found in only trace amounts in water can accumulate to

elevated levels in sediments. Sediment-associated contaminants can also directly affect benthic and other

sediment-associated organisms since sediments provide benthic and pelagic communities suitable habitats for essential

biological processes (e.g. spawning, incubation, rearing, etc.).

Sediments provide an essential link between chemical and biological processes. By understanding this link,

environmental scientists can develop assessment tools and conduct monitoring programs to more rapidly and accurately

evaluate the health of aquatic systems (Pardue et al., 1992). Therefore, sediment quality data provide essential

information for evaluating ambient environmental quality conditions in water bodies. Additionally, information about the

amount and quality of sediments within stormwater systems, stormsewers and other stormwater conveyances can help

trace pollution sources, prioritize areas for implementing control measures, and help to assure proper disposal of

accumulated sediments.

Inclusion of biological community monitoring allows a more holistic, systems approach that greatly enhances surface

water quality assessment and management (Yoder, 1989; Yoder and Rankin, 1997). In particular, it allows assessment

of the degradation of habitat (e.g., channel and bank erosion) and siltation within water bodies, neither of which are

54
detected by water chemistry sampling, and both of which are typically associated with wet weather discharges. While

chemical data reflect short-term conditions that exist when a particular sample is collected, biological communities

accurately indicate overall environmental health because they continuously inhabit receiving waters where they integrate

a variety of environmental influences - chemical, physical and biological.

Biological assessment involves an integrated analysis of functional and structural components of aquaticcommunities

(Karr and Dudley, 1981; Karr, 1991). Bioassessments are best used to detect aquatic life impairments and assess their

relative severity. Once an impairment is detected, additional chemical and biological toxicity testing can identify the

causative agent and its source. Both biological and chemical methods play critical roles in successful pollution control and

environmental management programs. They are complementary, not mutually exclusive, approaches that enhance overall

program effectiveness.

A fundamental part of bioassessments is “metrics” (Karr and Chu, 1998). Just as a doctor uses metrics such as blood

pressure and heart rate to assess human health, biological metrics allow the ecologist to use meaningful indicator

attributes to assess the status of communities in response to perturbation. The definition of a metric is a characteristic

of the biota that changes in some predictable way with increased human influence (Barbour et al., in review). By using

multiple metrics to assess biological condition, the information available about the elements and processes of aquatic

communities is maximized. The validity of an integrated assessment using multiple metrics is supported by the use of

measurements of biological attributes firmly rooted in sound ecological principles (Fausch et al. 1990; Lyons 1992).

In 1983, the DEP began developing assessment tools that could be used to assess stormwater and NPS effects and

the effectiveness of management programs, practices, and activities. The first efforts focused on estuarine sediment

assessment tools (FDER, 1988; Schropp et al., 1989,199O; MacDonald, 1994). In 1989, efforts began to modify national

bioassessment protocols (EPA, 1989) to develop quantitative bioassessment protocols for Florida (Griffith et al., 1994;

Barbour et al., 1996, FDEP, 1996). The tools that have been developed and that are under development (noted by a *)

include:

A. Sediment assessment tools

1. Standardized sediment collection and analysis protocols.

2. Estuarine normalization of metal concentrations to aluminum concentrations ratio.

3. Estuarine sediment quality assessment guidelines

4. Freshwater normalization of metal concentrations to aluminum concentrations ratio(*).

5. Freshwater sediment quality assessment guidelines(*).

B. Bioassessment tools:

1. Stream Condition Index

2. Lake Condition Index (* - nearly completed)

3. Wetland bioassessment methods (* - in early stages of development)

4. Canal bioassessment methods (* - in middle stages of development)

5. Estuarine bioassessment methods (* - in early stages of development)

Using the Tools for Watershed Management

Sediment assessment, together with watershed characterization, future land use plans, stormwater master plans,

and mapping of pollution sources, can be used to screen watersheds and sub-basins to determine potential “hot spots”.

55
Bioassessment and water chemistry sampling can then be done to assess the actual health of the aquatic system in these

locations. An important component of the bioassessment is habitat quality, especially since urbanization often leads to

dramatic changes in stream hydrology, geomorphology, riparian zones, habitats, and ultimately biological communities.

Possible outcomes of the bioassessment are: (1) no biological effects; (2) effects due to habitat degradation; (3) effects

due to sediment or water quality; or (4) effects due to a combination of sediment, water quality and habitat degradation.

Bioasssessments also allow the establishment of an ecologically-based aquatic resource goal, rather than one based

solely on traditional water chemistry standards to which the applicability to wet weather discharges is questionable. Once

an aquatic resource goal is established, then relationships between the needs of the biological community and the

chemical, sediment, and habitat influences on the community can be established. The next step is to then use all of this

information to develop a watershed management plan that includes specific projects, schedules, and funding sources that

will ultimately result in the acheivement of the desired aquatic ecological goal. Much of this effort can be coordinated and

implemented using the rotating basin approach that many states are now using in combination with the NPDES

stormwater permitting program.

Putting the Puzzle Pieces Together: Tampa Bay Case Study

Puzzle Piece 7: The Assessment- As part of the development of the Tampa Bay SWIM Plan (SWFWMD, 1992) and

the Tampa Bay NEP Comprehensive Conservation and Management Plan (TBNEP, 1996), existing environmental

information was assessed to determine the ecological health of the bay system. Major findings of these assessments are

summarized below.

Habitats

1. Since 1950, about half of the bay’s natural shoreline and 40% of its seagrasses have been destroyed.

2. In 1950, the bay’s shallow shelf supported about 40,000 acres of seagrasses. By 1982, only 21,600 acres

remained and virtually all of Hillsborough Bay’s 2,700 acres were gone. Seagrass decline is due to dredging and

filling for residential development, turbidity caused by dredging of the main shipping channel, and reduced light

penetration caused by shading by algae fueled by excess nutrient discharges.

3. Since the early 1900s approximately 13,200 acres of bay bottom (3.6% of the bay’s surface area) were filled, with

over 90% of the activity occurring along the bay’s shallow shelf where seagrasses once thrived. The surface area

of Hillsborough Bay has been reduced by 14%.

4. Upgrading sewage plants in the 1980s to provide advanced wastewater treatment reduced nitrogen loadings,

leading to a decline in phytoplankton, an increase in water clarity, and greater light penetration. Consequently,

between 1982 and 1992 seagrass coverage increased by about 4,000 acres (18.5%) raising the bay’s total

acreage to over 25,600 acres.

5. About 43% (9,700 acres) of Tampa Bay’s original saltwater wetlands were lost between 1950 and 1990, primarily

because of dredging and filling for waterfront development. However, as many as 5,900 acres of new wetlands

formed along causeways and other emergent land created by dredged spoil material during this period. Recent

estimates of wetland habitat in Tampa Bay indicate that about 18,000 acres of mangroves and saltmarsh remain

but many thousands of acres are damaged by invasion by exotic plants such as Brazilian pepper.

Fish and Wildlife

1. Between 1966 and 1990, the harvest of 11 commercial species of fish declined by 24%, primarily because of

smaller catches of mullet and sea trout. Each of these species is dependent on seagrass habitats.

2. Harvest of spotted sea trout declined by 86% between 1950 and 1990, from 487,000 pounds to 67,000 pounds.

Similarly, red drum harvests plummeted from 80,000 pounds in 1950 to 15,000 pounds in 1986.

56
3. Tampa Bay’s once-thriving shellfish industry has virtually collapsed, except for bait shrimping. Harvests of clams

or oysters are restricted or prohibited throughout the bay because of high bacterial levels associated with

stormwater discharges and septic tanks. The bay scallop, a highly pollution sensitive organism, all but

disappeared from the bay in the 1960s.

Water and Sediment Quality

1. While water quality has improved over the past ten years, primarily as a result of better wastewater treatment,

water clarity, nutrients, and toxics continue to be a problem.

2. Because of natural circulation and flushing from the Gulf of Mexico water clarity is greatest in the lower part of

Tampa Bay (2.5 m), and naturally decreases moving up the bay, dropping to an average of 2 meters (6.6 feet)

in Middle Tampa Bay and Old Tampa Bay. The lowest average water clarity is in Hillsborough Bay (1.5 m) which

has poor circulation and receives a larger share of nutrients and sediments from major rivers.

3. Excessive amounts of nitrogen continue to accelerate algal growth which subsequently reduces light penetration

to seagrasses and contributes to oxygen depletion. The bay’s total annual nitrogen load was estimated to be 2.5

times greater in 1976 than the load computed for 1985 to 1991 (Figure 1).

4. Recent studies by NOAA, in cooperation with FDEP, provide an excellent overview of the levels and distribution

of toxics in bay sediments (Long, et. al. 1991, 1994; FDEP, 1994). Compared to other urban estuaries, Tampa

Bay has low-to-moderate levels of most toxic parameters. Contamination is centered around large urban centers,

ports and marinas, and concentrations generally decrease from the top of the bay toward the Gulf of Mexico.

5. Generally, the highest levels of sediment toxic contamination occur in Hillsborough Bay, the bay’s most

industrialized area and home to the state’s busiest port. Upper Hillsborough Bay has the highest levels of

cadmium, copper, mercury, zinc, and lead, as well as the pesticide DDT. Concentrations in sediments at a site

in northern Hillsborough Bay were the highest of any toxic pollutant measured in Tampa Bay. Two other bays with

heavily urbanized watersheds, Boca Ciega Bay and Bayboro Harbor, also can be considered as hot spots of toxic

contamination.

6. Figure 2 shows sites in Tampa Bay where concentrations of toxic contaminants in sediments exceeded Florida’s

Probable Effects Level (PEL) and No Observable Effects Level (NOEL). Sites above the PEL indicate a high

probability for biological impact to marine organisms while those above the NOEL are considered “at risk” to

biological impact (MacDonald, 1994).

Puzzle Piece 2: The Goal: A critical component of watershed management is using biological living resources as a

measure of a water body’s health, with far less emphasis on traditional laboratory-based water quality standards. This

approach addresses critical ecological effects that are not seen by water chemistry standards, allows greater flexibility

to achieve the desired ecological goals, and provides taxpayers with a better benchmark to judge the return on their

expenditures. Through the SWIM Plan and the Tampa Bay NEP CCMP, the primary overall goals have been established

for the restoration and protection of Tampa Bay:

1. To reverse the environmental degradation of the Tampa Bay estuarine system.

2. To optimize water quality and other habitat values, thereby promoting the sustained existence or re-establishment

of thriving, integrated, biological communities.

3. To ensure the maintenance of a productive, balanced ecosystem complimentary with human needs and uses of

the resources.

57
Figure 1. Tampa Bay Total Nitrogen Loading and Sources

I

E 340 tend 48.2% I3

‘UT

4 la-d 11.8%

I Toial34ion8

II

Figure 1. Tampa Bay Total Nitrogen Loading and Sources.

58
Figure 2. Sediment Toxic Hot Spots in Tampa Bay

Figure 2 shows sites in Tampa Bay where concentrations of toxic

contaminants in sediments have exceeded Florida’s Probable Effects

Level (PEL) and No Observable Effects Level (NOEL) for biological

impact. Sites registering above the PEL indicate that some biological

impact to marine organisms is likely. Sites registering above the NOEL

are “at risk” to biological impact.

:f

.:. , :., : : :.

:.,qr ; .:, ,I.... I . . . . . . . . . . . . ./.I :,:. 1.: . . ..: i ::::f:($;:i $;v,: i.G :,::,, :/:

,:. ::: ; .. ,.,: ,::. ‘. ..:

,, ., j: >..:.;.. : :: ‘,v.:: .:, ?.::‘..:‘<: , :..: :: ..I l Sites exceeding I

Figure 2. Sediment Toxic Hot Spots in Tampa Bay.

59
To achieve these overall goals the following specific goals have been established:

1. The overall goal is to restore seagrasses to 1950s levels. This will lead to restoration of commercially important

species such as the bay scallop, mullet, sea trout, and red drum.

2. To restore seagrasses to 14,000 acres of the bay. The ability of seagrasses to recolonize the bay depends on

the amount of sunlight the grass species require, as well as shading factors such as the amount of drift macroalgae and attached algal growth on grass blades. For most seagrasses in the bay, an estimated 20% to 25% of

the light striking the bay’s surface must penetrate to target depths to allow seagrass regrowth. Reducing nitrogen

loadings will reduce chlorophyll a concentrations thereby increasing the depth of sunlight penetration.

3. As many as 12,000 acres of seagrass can be recovered by maintaining recent water quality conditions. This will

require local communities to reduce their nitrogen loadings to the bay by about 10% by the year 2010 to

compensate for increases in nitrogen loadings associated with the watershed’s population growth.

4. A coastal habitat master plan has been developed for the watershed that will help to coordinate and prioritize

existing state, regional, and local restoration programs. The long term goal is to recover 1,800 acres of lowsalinity tidal marshes while maintaining and enhancing salt marshes and mangroves at existing levels. A minimum

goal is to restore 100 acres of tidal marsh habitat every five years.

5. Reduce sediment toxicity to minimize risks to marine life and humans. Using three tests -evaluation of sediment

chemistry, sediment toxicity, and benthic community health - bay sediments will be characterized and prioritized

for management.

6. Reduce bacterial contamination to levels safe for swimming and shellfish harvesting.

Puzzle Piece 3: The PLRG: To achieve the ecological goal, nitrogen loadings would need to be held to those

occurring in 1992-94 meaning that the 17 tons of nitrogen loading that would accompany projected growth within the

watershed would have to be compensated. Reduction of nitrogen would reduce chlorophyll a levels which would increase

how deep the minimum levels of light needed for seagrass growth would penetrate the water column.

Puzzle Piece 4: C?uanti@hg Pollution Sources: Before load reductions can be achieved, it is essential that the sources

and relative contribution of the sources be quantified.

Figure 3 summarizes sources of nonpoint nitrogen loadings to Tampa Bay.

1. Stormwater runoff from the Tampa Bay watershed contributes about 47% of the bay’s total annual nitrogen load

with urban runoff accounting for about 16%, or 680 tons. Residential areas, the watershed’s largest land use, is

responsible for over half of the nitrogen loading while commercial/industrial sites account for about 20%.

2. About 28% of the bay’s total nitrogen loadings, or 1,200 tons, are from atmospheric pollutants falling directly on

the water. An additional 7,500 tons fall in the watershed, although no one can determine how much enters the

bay via stormwater. EPA estimates that as much as 67% of the bay’s total nitrogen load may be from the

atmosphere.

3. Stationary sources, primarily power plants, contribute an estimated 50% of the anthropogenic NO, emissions as

compared to 35% from motor vehicles.

4. Domestic wastewater discharges still discharge about 8% (340 tons) of the bay’s total annual nitrogen loadings,

even though all plants provide AWT. Hillsborough Bay receives about two-thirds of the cumulative nitrogen load

from the 36 billion gallons of effluent discharged to Tampa Bay each day.

5. Industrial wastewater discharges, primarily fertilizer manufacturing and shipping facilities, are responsible for

about 6% of the bay’s total annual nitrogen loadings.

60
Figure 3. Total Nitrogen Loadings

Per-Acre Nitrogen

from Non-Point Sources

X Lordlog X Watershed Yield Ib&adyr I

Ruidential 11 15.5 4.52

Commercial Indu6trlavln6iitutlon6I 5 6.4 5.26

Mining 4 3.2 4.97

RSng6 6nd P66t~ire 13 20.4 2.81

Intensive Agriculture 6 6.5 5.63

Undeveloped Land 8 39.93 1.15

Total Nlbvgen loading to Tampa Bay (1882-l 884 away)

F

lndz6Gial

WSSteWSter

- .-

Municipal 1

Wastewater

1

:ertllirer LO66e6

26%

Atmorphrrlc

Deposition

GrOundwater 1

47% B

Stormwater d

Runoff ~ 4 %

17%

Land 13%

PasturdRange

Land6

., ,,:r /. A

1.1 Residential

Industrial Runoff

Figure 3. Total Nitrogen Loadings.

6. Septic tanks, which serve about 20% of the watershed’s population, are another important source of nitrogen and

pathogen loadings, especially in some areas such as Allen’s Creek and tributaries to McKay Bay.

7. Another 7% of the bay’s total nitrogen loadings had been attributed to losses of fertilizer during ship loading and

en route to port. However, this figure has declined substantially since 1991 as source control BMPs were

implemented at the port.

61
8. More than 60% of the bay’s annual loadings of chromium, zinc, mercury and lead, as well as significant amounts

of petroleum hydrocarbons and pesticides are conveyed by stormwater.

9. Atmospheric deposition also is a major source of toxic substances accounting for 44% of the bay’s total cadmium

loading and about 17% of the copper and lead loadings. PAHs also enter the bay from the atmosphere.

10. Industrial and domestic point sources also contribute about 30% of the bay’s total loadings of aresenic, cadmium,

chromium, and copper.

Puzzle Piece 5: The Watershed Management Plan: The state’s Surface Water Improvement and Management

(SWIM) program was established by the legislature in 1987. Tampa Bay was named in the SWIM Act as a priority

waterbody within the Southwest Florida Water Management District and a SWIM Plan was adopted in 1992. In 1990,

Tampa Bay was adopted into the National Estuary Program by EPA leading to the development of Charting the Course,

a Comprehensive Conservation and Management Plan (CCMP) for the bay. Community participation was an essential

component of the development of both watershed plans. In particular, many of the agencies, citizen groups, and others

long active in the restoration and management of Tampa Bay participated in the development of the CCMP. The CCMP

built on many of the region’s ongoing environmental programs, from land acquisition to urban stormwater retrofitting to

habitat restoration. It also identified where unneccesary duplication existed in current environmental programs and

provided recommendations to ensure that limited public funds are spent in the most environmentally effective manner.

Puzzle Piece 6:Setiing PrioritiesTo assure that limited financial resources were used judiciously, restoration projects

and programs were prioritized and targeted to specific subbasins. This was done by combining GIS analysis with

watershed modeling and characterization with the results of the sediment, biological, habitat, and chemical assessments.

For example, an essential early activity of the SWIM program was a watershed-wide assessment of pollution sources,

especially stormwater, to identify “hot spots” - subbasins with high stormwater loadings - and to prioritize urban

stormwater retrofitting projects (SWFWMD, 1990). Similarly, priority habitat restoration sites were also selected as were

projects to reduce overall nitrogen loadings to the bay, including those from atmospheric deposition.

fuzz/e Piece 7: Action Hans: A successful watershed management plan must include a specific set of actions that

will be taken within a specified time. Charting the Courseincludes 41 specific actions that are needed to achieve the plan’s

goals. These include the construction of numerous urban stormwater treatment and habitat restoration projects that have

been built, are underway, or are planned in priority subbasins (Figure 4). Since vacant land in the highly urbanized area

is scarce or extremely expensive, many of these projects are being conducted on existing public lands providing multiple

benefits including regional stormwater management, open space, and recreation. Public education is a frequent

component of these projects with the placement of signs depicting the effects of urbanization, the importance of wetlands

and riparian vegetation, and the need for stormwater treatment and habitat restoration.

Programs and actions that rely upon nonstructural BMPs are also being used to reduce “Pointless Personal Pollution”

at its source and increase the effectiveness of existing programs. For example, since surveys showed that up to 70% of

the stormwater BMPs serving new development are not being properly maintained, assuring their long-term operation

and maintenance can greatly reduce stormwater pollution. Maintenance and operation of BMPs typically is the legal

responsibility of private land owners and property owner associations. Unfortunately, DEP, SWFWMD, and local

governments do not have enough staff to conduct regular inspections. To improve this deficiency, DEP is implementing,

in cooperation with local governments and the WMDs, a training and certification program for public and private sector

individuals involved in erosion, sediment, and stormwater inspections. Local governments also are encouraged to

implement Stormwater Operating Permit systems which require an annual inspection and certification that the stormwater

system has been maintained and is properly operating. As an economic incentive, some local stormwater utilities provide

credits for individuals served by a properly maintained and operating system. Additionally, Hillsborough County has

implemented the “Adopt a Pond” program to help educate stormwater system owners on how to maintain their systems.

Other nonstructural efforts include assisting businesses in developing and implementing pollution prevention plans

and the continued implementation of the Florida Yards and Neighborhoods Program. This program is being expanded

to help develop model landscaping guidelines for commercial landscapes, and promote the incorporation of FYN

62
Figure 4. Active SWIM Habitat Restoration and Stormwater

Retrofitting Projects

q

KILOMETERS

Figure 4. Active SWIM Habitat Restoration and Stormwater Retrofitting Projects.

landscaping guidelines into local government site review processes for new development. The region’s continuing rapid

growth provides opportunities through local government comprehensive plans and land development regulations to

promote compact development and to reduce impervious surfaces, especially parking lots at commercial developments.

Puzzle Piece 8: Assuring Implementation: An important aspect of any watershed management program is an

institutional framework that assures that all of the partners will implement their responsibilities. In 1998, an Interlocal

Agreement was signed by the Tampa Bay NEP’s local government and regulatory implementation partners. The

agreement requires the partners to submit detailed plans describing how they will fulfill their responsibitlities for bay

restoration and protection. Additionally, all of the local governments within the watershed have been issued, either as

individual permittees or co-permittees, NDPES muncipal stormwater permits. These permits include specific requirements

that are identified in the CCMP’s action plans.

63
Active Habitat Restoration Proiects 0

1. Lowry Park 9. Cabbage Head Bayou

2. NE McKay Bay 10. Boca Ciega

3. Delaney Creek 11. Cargil S. parcel

4. Simmons Park 12. Mangrove Bay

5. Hendry Fill 13. Cockroach Bay

6. Peanut Lake 14. Little Bayou

7. Bayshore Blvd. 15. MacDill AFB

8. Gandy Park 16. Picnic Island

Active Stormwater Retrofittinq Proiects n

1. Lowry Park 10. Brushy Creek

2. Horizon Park 11. Safety Harbor

3. Old Coachman 12.102nd Avenue

4. S. Pasadena 13. 94th Avenue

5. Jungle Lake 14. Lake Carroll

6. Pinellas Park 15. Delaney Creek

7. N. Redington 16. Haynsworth

8. EMS Site 17. 141st Avenue

9. St. Pete/Clearwater Airport

Puzzle Piece 9: Funding Implementation: Partners in the implementation of the CCMP include EPA, Florida DEP,

SWFWMD, local cities and counties, and the private sector. Each of the partners has made a substantial commitment

of financial resources since 1995 to accomplish the desired aquatic ecological goals. Primary funding sources have

included the P2000 (state and local land acquisition funds), the SWIM Program (state and SWFWMDfunds), SWFWMD

Basin Boards, the private sector, and local stormwater utility fees. In many cases, funding for projects is from a

combination of sources that often allow the leveraging of other funds needing nonfederal matching funds such as those

from the Section 319 nonpoint source implementation grant program.

Costs associated with the individual actions presented in the Tampa Bay SWIM Plan and the NEP CCMP are

considerable. However, these should not automatically be construed as requirements for new sources of revenues, since

some of these initiatives can and are being accomplished with existing resources or by redirecting current funding

allocations to better address the bay’s needs. A number of actions seek to improve coordination, cooperation, and

planning among state and local governments, and the private sector. These may actually result in cost savings for

currently funded activities.

A 1994 survey by the Tampa Bay NEP attempted to quantify how much money is spent to manage and monitor bay

quality and administer environmental programs. Based on FY94-95 budgets, the study indicates that over $260 million

is spent annually by federal, state, and local agencies on the restoration and management of Tampa Bay. As seen in

Figure 5, the largest par-t of the funds (65% or $170 million) are spent on wastewater collection, treatment, and reuse.

r Figure 5. Funds Spent

Figure 5. Funds Spent.

64
Approximately $35 million (13%) is spent by local governments and the SWFWMD on stormwater management.

Habitat restoration and land acquisition, two long favored and implemented environmental programs in the Tampa Bay

region, account for over $27 million in expenditures.

Puzzle Piece 70: Monitoring Implementation: Since the adoption of Charting the Course in 1996, numerous projects

and programs have been implemented. The Tampa Bay NEP recently issued the first official progress report on

implementation (TBNEP, 1999). It shows that the program’s partners are on or ahead of schedule in achieving most of

the priority goals for bay improvement. Highlights of implementation activities that occurred between 1995-99 include:

l Goal: Recover an additional 12,350 acres of seagrassover 1992 levels, while preserving the bay’s existing 25,600

acres.

Status: Since 1988, seagrass acreage is increasing at about 500 acres per year meaning the goal will be

reached in 25 years.

l Goal: Restoring and protecting bay habitats

Status: A total of 250 acres of low-salinity habitat will be restored in all bay segments, exceeding the five year

target by 150 acres. Additionally, a total of 1,340 acres of mangrove and saltmarsh habitat have been

restored. All 28 priority sites identified in the habitat master plan have been given the highest priority for

acquisition under the state’s land-buying programs.

l Goal: “Hold the line” at nitrogen loadings estimated from 1992-94.

Status: When fully implemented, the 105 projects constructed, underway, or planned will reduce the amount of

nitrogen entering the bay by an average of 134 tons per year, exceeding the target by 60%.

In addition to progress on the above goals, very good progress has been made on other goals. These include:

l The goal of protecting the endangered manatee population in Tampa Bay. The Manatee Awareness Coalition has

implemented “Manatee Watch” where trained volunteers help educate and encourage boaters to go slow in waters

frequented by manatees.

l The goal of returning bay scallop to Tampa Bay. Stocking programs are adding bay scallops and citizen volunteers

are measuring the effectiveness of these efforts through the Great Bay Scallop Search.

l The goal of reducing atmospheric deposition into and onto Tampa Bay. To better understand the linkage between

air pollution and water quality, eight research and monitoring programs addressing atmospheric deposition are

underway.

. The goal of making Tampa Bay safe for shellfish harvesting and swimming. As part of the “Healthy Beaches

Project”, research is underway to identify and test better indicators of microbial contamination, the prevalence of

the indicators at bay and gulf beaches, and probable sources of the contamination.

l The goal of providing flows necessary to support plant and animal communities below the dam on the Hillsborough

River. In February 1999, the SWFWMD approved a draft minimum flow rule for the Hillsborough River that hopefully

will provide a basis for resolving conflicts over competing uses of the river.

l The goal of developing a long term dredge material management plan for Tampa Bay. A Dredged Material Advisory

Committee is being organized in partnership with the U. S. Army Corps of Engineers.

Discussion and Recommendations

Florida has established a wide variety of laws, regulations and programs at the state, regional and local level to

protect, manage and restore the state’s incredibly valuable yet vulnerable natural resources, especially its water

65
resources. There is no doubt that these programs have been effective in helping to reduce adverse impacts on natural

resources resulting from the state’s rapid and continuing growth over the past twenty years. However, even with the

implementation of these programs, many of Florida’s natural resources have been severely strained or degraded. Some

of these adverse effects can be attributed to activities that occurred before the implementation of modern watershed

management programs such as the channelization of the Kissimmee River and the creation of the vast drainage canal

network south of Lake Okeechobee both of which are contributing to the decline of Lake Okeechobee, the Everglades

and Florida Bay. Other adverse impacts, though, are directly related to the state’s rapid growth and development during

the last twenty years. These include water supply problems, water quality problems, declining habitat and impacts on

endangered species such as the manatee and the Florida panther.

Why are these adverse impacts still occurring given the wide range of watershed management programs that have

been implemented in Florida? What could be done to reduce these effects and possibly restore already degraded areas?

The continuing evolution of Florida’s land and water management programs into a more holistic approach which seek to

manage cumulative effects can help to overcome many of the current program deficiencies. Cooperative efforts and

partnerships, together with citizen education and involvement to improve the stewardship ethic of all Floridians is

essential. With increased support and participation by all Floridians, the effectiveness of the state’s programs can be

improved helping to assure that our natural resources will be able to be enjoyed by future generations.

References

Barbour, M.T., J. Gerritsen, and J.S. White. 1996. Development of a Stream Condition Index (SCI) for Florida. Prepared

for Stormwater/NPS Management Section, FDEP, Tallahassee, Florida.

Barbour, M.T., J.B. Stribling, and J.R. Karr, (in press). The Multimetric Approach for Establishing Biocriteria and

Measuring Biological Condition. Jo W. Davis, T. Simon (eds.), Biological Assessment and Criteria: Tools for Water

Resource Planning and Decision Making. Lewis Publishers.

Barbour, M.T., J.B. Stribling, and J.R. Karr, (in review). Biological Criteria: Technical Guidance for Streams. U.S.

Environmental Protection Agency, Office of Science and Technology, Health and Ecological Criteria Division, Washington,

DC.

EPA. 1989. Rapid bioassessment protocols for use in streams and rivers: Benthic macroinvertebrates and fish.

EPA/444/4-89/001. Washington D.C.

Fausch, K.D., J. Lyons, J.R. Karr, P.L. Angermeier. 1990. Fish communities as indicators of environmental degradation.

Am. Sot. Symp. 8:123-44.

FDER. 1988. A guide to the interpretation of metal concentrations in estuarine sediments. Florida Dept. of Env.

Regulation. Office of Coastal Zone Management. Tallahassee, FI.

FDEP. 1994. Florida coastal sediment contaminants atlas and technical volume. Florida Dept. of Environmental

Protection. Sediment Research Group. Tallahassee, FI.

FDEP. 1994. Florida Coastal Sediment Contamination Atlas. Office of Water Policy, Tallahassee, Florida.

FDEP. 1996. Standard Operating Procedures for Biological Assessments. Bureau of Laboratories, Tallahassee, Florida.

Griffith, G, J. M. Omernik, C. Rohmand, S. Pierson. 1994. Florida regionalization project. USEPA Environmental Research

Laboratory. Corvallis, Oregon. Final Report Prepared for Fla. Dept. Environ. Protection. Tallahassee, FI.

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84.

Karr, J. and D. Dudley. 1981. Ecological perspective on water quality goals. Environ. Mgmt. 5(l): 55-68.

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Karr, J.R., and E.W. Chu. 1998. Restoring Life in Running Waters: Better Biological Monitoring. Island Press, Washington,

D.C.

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Effects in Tampa Bay, Florida. NOAA Technical Memorandum NOS OMA 58.

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78.

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report submitted to FDER/SRG. Tallahassee, FI.

MacDonald, D. 1994. Approach to the Assessment of Sediment Quality in Florida Coastal Waters. Final report submitted

to the Florida Department of Environmental Protection, Tallahassee, Florida.

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67
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Engineering Foundation Conference. ASCE, New York.

68
Urban Stream Structure And Selection Of Structures To Build Habitat

To Support Wild Fish Populations

Douglas T. Sovern

URS Greiner Woodward-Clyde

Seattle, Washington

Abstract

This paper gives a brief overview of the physical impacts of urbanization on streams and examines the selection of

in-stream methods, tools, and devices for stabilizing streams and creating habitat to support native fish species. Although

the paper discusses salmonid species in the Pacific Northwest in particular, the methodologies and tools employed to

evaluate and support fish habitat can be generally applied to streams and watersheds in other regions.

The effects of urbanization, such as decreased pervious area and vegetative cover and increased stormwater runoff

and erosion, destabilize watersheds and streambeds and destroy aquatic habitats. Stable stream environments are

necessary if biological systems including fish and their supporting food web are to flourish. Changes to urban streams

and watersheds may be so significant, however, that decades may pass before they reach stability. Even then, the

resulting Astable environment@ might not provide the type of habitat needed to support species from the natural

environments.

The evaluation of channel erosion and sedimentation in urban streams provides one measure to assess the relative

stability of streams and, thus, their ability to support fish and amphibian species. For most streams, an evaluation of

relative streambed stability can be completed through a visual examination of streambed morphology and minimal

supporting calculations. Tools for performing these analyses will be presented in this paper.

Rehabilitation of streams in urban and heavily logged watersheds requires establishing a stream structure that will

maintain streambed stability and create the different types of habitats needed to support desired fish species. One size

or type of in-stream device cannot meet all stabilization and habitat requirements. The selection of devices should

correspond to the relative stability of the individual stream reach. Devices for maintaining streambed stability and creating

habitat, as well as the procedures for selecting them, will be discussed in this paper.

Introduction

Salmon populations in the Pacific Northwest are dwindling. One significant cause of this reduction in population is

the destruction of small stream (1” to 41h order) habitats.

In order to respond to the destruction of fish habitat in small streams, we must have an understanding of watershed

processes and natural stream morphology. Although this paper concerns western Washington streams, which are

surrounded by heavy forests and fed by rain and groundwater, the general principles for stabilizing streams discussed

here can be applied to most natural small stream systems.

Natural Stream Morphology

Streambed gradients gradually decrease from the upper reaches of a watershed to the outlet of a stream because

flow rates increase in the lower parts of the watershed (Leopold, Wolman, and Miller, 1964).

The streambed gradients create different types of fish habitat features (Rosgen, 1994). Figure 1 shows the

relationship of habitat type to streambed slope in western Washington streams. Pool/drop habitat is dominant in reaches

with smaller flows and steeper valley gradients. The pools are formed by large organic debris or rock formations. As the

stream flow rates increase, valley gradients tend to decrease and the streams are dominated by pool/riffle habitats.

69
PLANE EIED

GIDES

PClOllRROP

PWRIFRE

Figure 1. Relationship of Stream Habitat to Streambed Slope in Western Washington Streams.

Pools and riffles form alternately on the outside of stream bends. These alternating pools and riffles are present in

practically all perennial channels. In straight or meandering streams, pools and riffles generally form every 5 to 7 channel

widths. As the stream widths increase, however, the number of pools decrease (Leopold, Wolman, Miller, 1964).

In each non-rigid, natural stream, a dominant channel is formed by the stream=s dominant discharge. This dominant

discharge channel is a component of most fish habitats. The dominant discharge has a recurrence period of

approximately once each 1.5 years in natural systems (Simons, Senturk, 1991). In urban systems, the bank-full discharge

has a recurrence period of about one year (MacCrae, 1996).

Western Washington Natural Stream Characteristics The small streams of western Washington are fed by rain and

groundwater and are found in steep-sided canyons with fairly straight valley bottoms. In their natural (forested) state,

small streams have a slightly meandering, low-flow channel in a narrow valley bottom. The vegetation along the stream

banks is often dense and provides shade, channel stability, and cover. Debris jams are common and act to slow stream

flows during storm events. Western Washington soils are products of glacial activity and consist of smooth cobbles and

stones, as well as fine materials. Clayey bank materials, heavy root structures along the banks, and steady base flows

create channels with nearly vertical sides and small widths (3 to 6 feet wide, and sometimes as small as 1 foot wide)

relative to the width of the valley bottom. Typical old-growth forest streams have low nutrient levels and low annual

sediment yields.

70
Most natural Pacific Northwest streams can be described as sediment starved. Natural watersheds are heavily

forested and act as a sponge for rainfall. In natural watersheds, the storm runoff response is slow and the flow rates are

low. Because the ratio of the 1.5-year storm to the base flow is quite low (often less than 5), these streams have small

width to depth ratios, with most of the dominant discharge channel acting as an aquatic habitat channel. The width of the

dominant discharge channel is coincident with the width of the aquatic habitat channel. The aquatic habitat channel is

the normally wetted, low-flow part of the streambed (Seattle, 1997). Most small, natural Western Washington streams

are dominated by pools and drops formed by large organic debris (Gustav, Sovern, Washington, 1993)

The aquatic biological community in western Washington may include as many as 250 plant and animal species. The

aquatic biological community depends on a stable aquatic habitat associated with old growth, coniferous watersheds.

Much of this aquatic community functions as a food web, with fish populations representing the mega fauna. Some

salmon and trout species are the top aquatic predators (Sovern, Washington, 1996).

Salmon and trout in western Washington evolved to take advantage of these regional stream conditions. Figure 1

lists different species found in the various regions of the watershed. More athletic fish species like coho, steelhead, and

cutthroat trout occupy the upper reaches (steeper gradient) of the watershed. The young coho and steelhead reside in

the stream for a year before migrating to saltwater. Cutthroat may reside in fresh water for two years before migrating

to saltwater. Less athletic species, such as chum and pink salmon, can not migrate through the steeper gradients of the

upper watershed to spawn. The fry of these species occur in the lower regions of the watershed and migrate to saltwater

shortly after emergence. Young salmon, as well as young and adult trout, will utilize any part of the watershed that meets

their habitat requirements. For example, if fish habitat in the upper reaches of a watershed is unsuitable, young coho may

seek winter refuge in the lower regions of a watershed (Sovern, Washington, 1996).

Five general categories of habitat occur in natural western Washington streams (Sovern, Washington, 1996):

l Estuaries/Deltas

l Passage

l Refuge

l Rearing

l Spawning and Incubation

Pacific Northwest fish derive most of their food from organisms (benthos) that live in, or on, the substrate of the

stream. Most food production occurs in the same stream areas that provide spawning and incubation habitat for fish. An

annual surplus of approximately 10 pounds of biomass is required to support one pound of fish in the stream (Washington,

1999).

Assessing Stream Deterioration

Visual inspection of stream morphology can provide rapid and relatively accurate assessments of astream=s ability

to support fish populations. Practical experience working in western Washington streams has shown that visual

streambed assessments correlate well with benthic sampling (Seattle, 1999). Although benthic sampling is necessary,

visual inspections can reduce the amount of benthicsampling required when quickassessments are needed orextensive

benthic testing is cost-prohibitive.

Natural streams are generally non-rigid. Their cross-sections vary with changes in flow rates and yearly rainfall

volumes. Stream systems will generally aggrade during low flow periods, and degrade during high flow periods. To

assess the deterioration of non-rigid streams, it is necessary to understand the following three concepts:

*Sediment transport

71
*Effects of urbanization on stream stability

*Effects of urbanization on fish habitat

Sediment Transport Concepts Understanding the dynamics of sediment transport is useful for predicting hydraulic

equilibrium conditions in a stream. Any stream will respond to imposed changes. Six basic relationships exist between

discharge levels and channel form, regardless of stream size (Simons and Sentiirk, 1991):

Depth of flow in the dominant discharge channel is directly proportional to discharge.

l Width of the dominant discharge channel is directly proportional to water discharge and sediment discharge.

l Dominant discharge channel shape is directly related to sediment discharge.

l Channel gradient is inversely proportional to water discharge and directly proportional to sediment discharge and

grain size.

l Sinuosity is directly proportional to valley gradient and inversely proportional to sediment discharge (larger valley

gradient causes greater meander, larger sediment discharge causes less meander).

l Transport of bed materials is directly related to flow velocity and concentration of fine material, and inversely

proportional to the fall diameter of the bed material (greater depths and higher velocities cause larger bed load

volume in transport, sediments shaped like kites fall slower than round-shaped sediments).

A stable channel exists when a stream has the bed slope and cross-section which allow its channel to transport water

and sediment from upstream without aggradation, deposition, or streambank erosion (Simons and Senturk, 1991).

When natural flow rates are exceeded, sedimentation and erosion can be a dominant limiting factor for fish

populations. The exaggerated volumes and rates of stormwater runoff in urban areas increase both the rate of erosion

and volume of sediments generated from upland and riparian areas in the watershed. Soil erosion can lead to excess

streambed erosion and sedimentation and destroy redds, fish rearing habitats, and food production areas.

Effects of Urbanization on Stream Stability Urbanization permanently alters the hydrologic balance within stream in

the following ways:

. Total water passing through urban streams increases.

. Stormwater runoff rates and volumes increase.

l Increased impervious surface areas prevent groundwater recharge; as a result, base flow rates during summer and

fall are often less than natural flow rates were.

l Increased stormwater runoff causes erosion and transports significant amounts of sediments and pollutants,

including oil, grease, and polluted fine sediments from streets and parking lots, into urban streams,

In urban areas, the ratio of the 1 -year storm to the stream=s base flow (dominant discharge) is large, sometimes

greater than 100. In many watersheds, terrestrial sediment volumes are dramatically increased by urbanization. Excess

sediment increases the width of the dominant discharge channel.

Stable urban streambeds have 182% gradients, compared to the 2810% gradients that support anadromous species in

natural watersheds. To reach a stable gradient, the streambed can lower several feet, causing significant bed load

sediments from shallow landslides. Measurements taken from several western Washington streams show that

streambeds will flatten from a 4% gradient to a 1% gradient as a result of urbanization. A change in streambed gradient

from 4% to 1% over the distance of 1,000 feet can result in streambed erosion and an elevation difference of 30 feet at

the upper end of the reach. During the transition from steep to flat gradients, fish habitat is in a perpetual state of change

(Sovern, Washington, 1996). Unfortunately, it can take decades before stability is again reached.

72
In unstable streams, braiding occurs at crossover points between bends where stream gradients are steep. At normal

stage, a braided section has a divided flow with small, mid-channel bars and a single large channel composed of

subordinate channels. The base flow channel often changes location within the bottom of the dominant discharge channel

(Sovern, Washington, 1996).

The erosion of the channel bottom along the basin (often called head-cutting) indicates a readjustment of the basin’s

gradient, the stream discharge, and the sediment load. (Simons and Sentiirk, 1991).

Effects of Urbanization on Habitat Stable habitat conditions within the channel have stringent requirements in urban

streams, including a sediment-starved condition and minimal movement of spawning-sized gravel (3-inch and smaller)

during most storm runoff events.

In urban streams, the benthic system can be limited both by erosion (which provides conditions of constant change) and

by sedimentation (which smothers redds and food production areas, and fills rearing habitats with silt). In addition,

streams in urban or deforested watersheds experience significant habitat loss and are unable to support the biological

diversity that fish species depend upon. In contrast to natural watersheds, where 250 plant and animal species may

comprise the aquatic habitat, urban watersheds may have fewer than 50 plant and animal species.

Living systems do not adapt to constantly changing environmental conditions. The changes in aquatic habitats

caused by urbanization decrease food production and destroy spawning and incubation areas (Bell, 1990). As flow rates

and volumes increase, streambeds become unstable. When streambeds become unstable, the aquatic habitat channel

may retain a small width to depth ratio, but it will be substantially less than the width of the dominant discharge channel.

In addition, streambed instability causes a constant shifting of the aquatic habitat channel and this limits development of

the benthic community and destroys redds.

As an urban stream approaches stability, the resulting aquatic habitat channel will be too wide, shallow, and

homogeneous to support fish populations. Streams naturally deposit bed load on the inside of bends and form point bars.

Because natural sinuosity is low in western Washington streams, point bars form infrequently or incompletely leaving a

wide, shallow, cross section during base flows. Under these conditions, the flow depths of most urban streams are

insufficient to submerge returning adult fish. Because small-grained sediments settle as flow rates decrease, redds and

food production areas are smothered with silt and pool habitats are filled with sediment.

Perhaps the greatest general impact is the permanent loss of habitat types that sustain coho and steelhead

populations. These species prefer pool/drop habitat. Coho, in particular, require quiet pools (Seattle, 1997). Examination

of Figure 1 shows that as the streambed gradient lessons, the habitat type shifts from pool/drop to pool/riffle. Pool/riffle

habitat does not provide sufficient pool depth for normal fish rearing or urban storm refuge. Because large storms

frequently occur after the fry emerge from the streambed gravels, the need for urban storm refuge habitat is critical.

Juvenile fish cannot maintain their position in high velocity reaches. In fact, normal urban storm flows often wash juvenile

fish into larger bodies of water (salt water or streams) where they cannot survive.

Tools and Methodologies

The methodologies available to assess existing stream conditions and predict future conditions include the use of visual

streambed assessments and analytical tools such as simple hydraulic mathematics.

Streambed Assessment

General indicators of habitat degradation in urban streams are visually apparent and include the following elements:

l Dominant discharge channel wider than in natural conditions

l Reduced pool frequency and less diverse habitat

l Increased sediment from terrestrial sources

73
l Reduced large woody debris

l Drastically reduced aquatic community diversity

Both natural and urban streams fluctuate between stability, degrading, or aggrading. Compared to natural streams,

however, streams in urban watersheds exhibit extreme traits of aggradation, degradation, or instability. Urban stream

deterioration indicators differ according to the condition of the specific reach (stable, degrading, or aggrading). In a

degrading streambed, there is a progressive lowering of the channel due to scour. In an aggrading streambed, there is

a progressive buildup or raising of the channel due to sediment deposition. Both degradation and aggradation are

indicators that a change in the stream=s discharge and sediment load is taking place (Simons and Senturk, 1991).

Urban stream deterioration indicators differ according to the condition of the specific reach. Table 1 (the following

bulleted paragraphs) describes the deterioration indicators in a stable, degrading, or aggrading stream.

Table 1. Urban Stream Deterioration Assessment Indicators

Stable B If an urban stream reach is stable and terrestrial sediment loads are low, the reach may be able to support species that reside temporarily in the

stream before moving to salt water. The wide, shallow channel of a stable stream provides little protection from predation, however, and also lacks resting

pools. The following are indicators of stable urban streams:

l Apparent changes in channel shape and configuration afler large storms are small.

l Width of aquatic habitat channel coincident with width of dominant discharge channel B shallow flow depth, prevents fish passage.

l Head-cutting and nick points are absent or nearly absent.

l Substrate stability:

l Periphyton stays on streambed after significant storms B streambed is stable.

l Streambed gravel lack periphyton B gravel is being moved during significant runoff and replaced when the storm flow recedes,

. Small-grained sediments settle when storm flows recede, smothering redds and food production areas.

. Pools (on-stream or off-stream) that can retain newly hatched fry are generally not present.

Degrading B In a degrading urban stream the dominant discharge channel is as wide as in a stable stream, but base flow rarely covers the bottom of the

channel except at crossover points between bends. When streams begin to unravel due to degradation, the effects do not appear instantly. Head-cuts

move through a stream until it reaches a vertical drop. When enough head-cuts accumulate, the vertical drop will be undercut, releasing large amounts

of bed load type sediments. Occasional pools will develop that may support anadromous fish, however, they are often inaccessible.

l Streambed gravel sizes are larger than stable sections of the stream, but are mostly bare of periphyton or other aquatic growth.

l Channel braiding occurs at crossovers between bends.

l The substrate of the base flow channel is not coated with periphyton.

l The base flow channel and dominant discharge channel lack large woody debris.

l Large woody debris that spans the banks of the dominant discharge channel may indicate a recent streambed elevation and may illustrate the

amount of degradation that has occurred.

l Stream banks are bare and often nearly vertical.

Aggrading B Aggrading stream reaches may be visually similar to stable reaches. Generally, aggrading streams will have a flatter streambed gradient

and accumulate more fine sediment. Disturbing the bed of an aggrading reach usually results in long periods of murky water flow. Aggradation will occur

locally in pools, which reduces habitat value, but has less impact on habitat than an entire aggrading stream reach would.

l Head-cuts and nick points do not exist.

l Deltas may be visible at the top of the reach.

l Periphyton covers the substrate.

l Large woody debris in streambed is partially buried.

l Pool/riffle and pool/drop habitat can occur as isolated conditions.

l Substrate surface oravel sizes are small.

The visual indicators described in Table 1 (combined with assessments of fish passage problems and periodic benthic

population checks) can be used to describe the potential habitat capacity for a stream reach or, collectively, for an entire

stream. Needless to say, habitats for fish species that reside in the stream for one year or longer must be able to support

the full life cycle of the species. In addition, fish need to have full access to these habitats.

A methodology based on visual streambed assessment was developed for rapid stream assessments in Longfellow

Creek and Pipers Creek in Seattle, Washington (it was also used within six watersheds in Snohomish County,

Washington). The streambed assessments provided an accurate measurement of the ability of the watershed or stream

in question to support fish. An example of the summary rating for Longfellow Creek is shown in Table 2.

74
Table 2. Summary Rating for Longfellow Creek

Creek

4

5

6

7

8

9

10

11

12

13

Description

Pipe from outfall to Andover Street

Open channel from Andover Street to

Genessee Street

Open channel from Genessee Street to

confluence of unnamed tributary in West

Seattle Golf Course

Unnamed tributary in West Seattle Golf

Course

Open channel from confluence with West

Seattle Golf Course tributary to Brandon

Street

Open channel from Brandon Street to Findlay

Street. Contains confluence of Juneau Street

bypass via “biochannel.”

Open channel from Findlay Street to Juneau

Street. Also contains piped high flow bypass

starting at Juneau Street and rejoining Creek

in Segment 6.

Open channel from Juneau Street to Graham

Street

Open channel from Graham Street to Willow

Street

Open channel from Willow Street to Myrtle

Street

Piped channel Webster Basin; open channel

to Holden Street. Contains “K-Mart bypass.”

Open channel from Holden Street to Thistle

Street

Pipe from Thistle Street to head of basin at

Roxbury Street

Map

Sheet

123

415

%i7

Habitat’

5

10

10

6,7 6

7,&g 9

9 9

9,lO 8

10,ll 11

11,12 8

12,13 8

13,14 7

14,15,16 8

16 6

Notes:

Bank Sediments Other

Erosion’ Sources* Pollutants*

3 3 2

1 1 2

2 2 2

2

1

2

2

2

2

2

2

2

3

2

1

2

2

3

1

2

2

1

1

2

2

2

2

2

2

2

2

2

2

Total

13

14

16

12

13

15

14

18

13

14

13

13

12

Ranking Codes:

1 = Poor condition

2 = Moderate

3 = Relatively good

l = The value in the “habitat” column is the result of another ranking process. The total “habitat” volume for each Creek segment is

transferred into this table to complete the ranking process. The habitat rank has a range of O-18 which is developed from evaluating bed

erosion, fine sediment accumulation, gravels (clean/stable), benthic (quantity, quality), habitat structure, and riparian vegetation. All other

columns in this table are ranked from 1 (poor condition) to 3 (relatively good condition).

Analytical Tools Simple hydraulic mathematical tools can be applied to analyze existing conditions and are

needed to check passage conditions for channel rehabilitation projects. In addition to depth and velocity, the amount

of turbulence in a stream has significant impact on the amount of sediment that can be moved. Greater turbulence

increases the amount and size of sediments that can be moved. Maximum turbulence occurs when the Froude

number is equal to 1 .O. The Froude number is defined by Equation 1:

F,= V/(gY)ln (Equation 1)

Where

F, = Froude number

V = average velocity in the cross-section

g = acceleration force due to gravity

Y = the hydraulic depth, which is the cross-sectional area divided by the top width

75
The Froude number should not exceed 0.8 for large storms (like the 25 or loo-year event) except at channel drops.

This criterion is the same for rigid, grass, and dirt lined channels in most stormwater manuals. For frequently occurring

storm flows (1 to 2 year events), the Froude number has to be much less in order to meet the criteria for larger flows.

Spawning-size gravel will generally be stable if this Froude number criterion is met.

In the author’s experience, backwater analysis (HEC-2 or HEC-RAS) may not be strictly applicable to analyze natural

streams, but is a useful tool to analyze deteriorated channels and to model proposed improvements for stream

rehabilitation. For stream rehabilitation backwater analysis is done for large and small events (base flow, 1 -year flow, and

one point in between) to ensure passage of juveniles throughout their life-cycle habitat within the stream. To provide

accurate results, more cross-sections are needed to conduct backwater analysis on non-rigid, urban streams compared

to conventional backwater analysis.

Selecting Rehabilitation Devices

Unless excess stormwater from both frequent and rare storm runoff events can be eliminated, it is the author=s

opinion that some form of structural intervention is needed to create fish habitat in urban streams. In western

Washington, streams become unstable and significant fish habitat is lost when the impervious area reaches 10 to 15

percent (Booth, 1996). The dominant discharge channel will respond to hydrologicchanges (Simons and Senturk, 1991).

As a result, modifying how land is urbanized can reduce the effects of urbanization, but it will not obviate the hydraulic

impact on the dominant discharge channel. Stream rehabilitation measures will still work best where there are fewer

disturbances to the watershed and where wide riparian corridors are maintained.

The goal of urban stream rehabilitation is to stabilize the streambed with devices that also create a habitat for fish

populations. The stream must develop sufficient food mass and diversity to support desired fish species. Quality salmon

and trout habitat can exist in urban streams when hydraulic/habitat criteria are met, the streambed is stable, and the base

flow channel is confined (Sovern and Washington, 1996).

Establishing stable streams in urban watersheds is often a moving target. As more urbanization occurs, hydrologic

and biological changes accumulate. The extent that the dominant discharge channel spreads is a direct function of the

amount of pavement in a watershed.

The New Urban Stream. Restoring an urban stream to pre-development conditions is not possible (National Research

Council, 1992). It is the author’s opinion that too many stream rehabilitation projects emphasize stream bank rehabilitation

rather than focusing on the root causes of stream habitat destruction. Often, that root cause is streambed instability,

which is a natural response to increased flow rates and volumes in the stream.

To maintain pre-development species in urban and deforested streams, a “new urban stream” is needed that can

provide a variety of fish habitats including pools. Without intervention, the urban streams will convert pool/drop habitat

into pool/riffle habitat, eliminating the diversity of habitat required to support a variety of fish species (Sovern and

Washington, 1996).

The goal is to stabilize the stream and return it to its original sediment-starved condition. While bed load and

suspended sediment are readily available, the object is to sculpt sediment deposition to form bars and banks and confine

the aquatic habitat channel within a single location. Concentrating flows in the aquatic habitat channel helps keep the

substrate size optimal and clears the stream of fines.

Urban stream rehabilitation must focus on historic conditions that can be recreated, rather than on the conditions

that cannot be meaningfully restored. Except for the following three exceptions, historic environmental conditions can

be recreated in urban streams:

l The width of the dominant discharge channel will always be greater in urban streams.

l The banks of the aquatic habitat channel cannot be coincident with the dominant discharge channel (in pool/riffle

habitat).

l High flood flows, deep flow depths, and large velocities are more frequent.

76
In form, the resulting channels resemble snowmelt type streams, where flow rates significantly exceed base flows

for several weeks each year. Most urban streams lack large woody debris that can be incorporated into the stream’s

structure when a reach attains stability. Most reaches will take decades to reach stability. Just because the channel will

not look “natural”, doesn’t mean that we will have failed or that anadromous species cannot be supported. Many eastern

Washington snowmelt type streams support anadromous species.

A rehabilitated stream has five primary needs:

l A dominant discharge channel sized to carry the 1 -yearto 1 S-year storm (depending on the degree of urbanization)

at full bank. It is important to recognize this need because the stream will reshape the dominant discharge channel

and may undo much of the rehabilitation effort.

l Within the dominant discharge channel, hydraulic conditions must provide biologic and stream stability (keep most

of the spawning sized gravel and rock from moving during frequent storms).

l Within the dominant discharge channel, habitat must be provided for the entire life cycle of the desired species.

l Because fine-grained sediment falls out last and needs to be kept in transport, the base flow channel has to be

narrow, deep, and stable.

l Stream banks need to be stable to support riparian vegetation. Bio-stabilization techniques can help reduce the

width of the dominant discharge channel.

Ideally, long reaches of unstable streams will be stabilized. Near the spanning structures, aggradation will replace

degradation (as long as a sediment supply is available). If only short reaches are stabilized, large storms will deposit

substantial sediments within the stabilized reach, particularly at the upstream end of the reach. The sediment sizes most

likely to accumulate during the stabilization of a reach are the larger sizes that are moved as bed load. Once stable

streambed gradients are attained, the amount of sediment that can move and cause aggradation is finite. After a few

larger storms, bed load movement will be minimal.

Rehabilitation Devices A variety of devices may be used to confine the base flow channel and provide streambed

stability. The author has experience with several types of bed control structures, glides, lunkers, and confining devices.

In small streams, these devices may be a well-placed piece of timber, a boulder, or randomly placed stones and rootwads

(to increase roughness). In larger streams, stabilization and confining devices are much more complex.

Selection and siting of devices is dependent on the stream condition in a specific area and the type of habitat that

is to be provided. It is important to realize that one type of structure is not suitable for all applications. Selection of a

stream rehabilitation device depends on the type of habitat needed and the device’s perceived hydraulic attributes. Both

non-rigid channel design and biologic skills are required to be successful.

This section will address issues related to the selection of three types of structures: timber stepdown structures,

boulder bed control structures, and deflectors.

Timber Stepdown stepdown. Sometimes referred to as a “K-structure”. A form of timber is shown in Figure 2. The

logs, which are set at 45 degrees to the channel, are called weir logs and create pools during high storm flows. The weir

logs need to have a steep pitch (the bank end higher than the center of the stream). In dense, urban western Washington

watersheds, storms with high yearly return frequencies produce flows 20 to 50 times the base flow. Timber stepdown

structures form large, quiet pools during storms, allowing newly emerged fish juveniles to find refuge. In

77
Figure 2. Timber Stepdown K-Structure (shown with weir logs).

addition, the K-type stepdown creates rollers. Rollers assist fish passage upstream for less athletic adults and juveniles

during higher flow rates (Kerr Wood Leidal Associates, LTD, 1980).

Common variations of the K-structure include a straight timber stepdown (no weir logs) and a vortex structure (with

weir logs). In creating a diverse habitat environment, both types can be used.

While the straight timberstepdown does not form an upstream pool, the substrate above the stepdown is turned-over,

even for frequently occurring storm flows. The Washington Department of Fisheries and Wildlife has successfully installed

many straight timber stepdowns in logged watersheds and those with minimum to moderate urbanization. For lower flow

rates, the substrate above the stepdown remains stable and provides excellent spawning habitat.

The vortex type timber stepdown does not form storm refuge pools as well as the k-structure and the log configuration

stymies formation of a roller. The structure can help develop confined low flows, however, and creates good fish-rearing

habitat for many northwest species (not Coho).

Boulder Bed Control Structure. Figure 3 shows a boulder bed control structure. Like the K-structure, the boulders

that form the structure are on the upstream side, but these boulders could also be on the downstream side to form a

vortex-type structure. In the author’s experience, changing the configuration and the angles of the boulders provides

slightly different habitat characters, all of which are acceptable. While wood is usually preferred in small streams, boulder

bed control structures are flexible and can adjust to channel degradation in unstable streams. Boulder bed control

structures are most beneficial at the downstream end of a reach where no streambed control is established in the reach

below.

Deflectors. Deflectors can be made of either wood or boulders. Figure 4 shows a timber deflector with a bank log on the

opposite bank. Point bars form on the insides of bends. Deflectors should be installed on the insides of bends to help

build larger point bars and to confine the base flow channel. The reach in Figure 4 is nearly straight (sinuosity about 1 .O).

To develop point bars in straight reaches, several deflectors may be needed and could be on one side of the channel,

or on alternating sides. The reach shown in Figure 4 has a large bed load, and point bar formation would have occurred

if the deflector installations were correctly located and implemented. Without modification, however, the deflector shown

in Figure 4 will not form a point bar.

78
Figure 3. Boulder Bed Control Structure.

Figure 4. Deflector.

Conclusions

Streambed assessment based on sediment transport principles can be a useful tool to rapidly determine a stream’s

capability to support fish populations. Standard engineering analytical tools can be used with streambed assessment to

support hydraulic design for stream rehabilitation projects. Although the stream will not have the same appearance as

a natural stream, stream rehabilitation can be successful and urban streams can support anadromous fish populations

in western Washington. Hydraulic design is needed to develop the dominant discharge channel and properly place

structures to attain the desired habitat conditions. Selection of the rehabilitation devices must consider design needs of

non-rigid channels, as well as habitat requirements. Finally, one size or type of habitat rehabilitation device cannot serve

79
all purposes. Selection of habitat rehabilitation devices should achieve specific habitat requirements and provide habitat

diversity.

References

Bell, Milo C., Fisheries Handbook of Engineering Requirements and Biological Criteria, US Army Corps of Engineers,

Portland, Oregon, January, 1990.

Booth, Derek B.; Montgomery, David Ft.; Bethel, John; “Large Woody Debris in Urban Streams of the Pacific Northwest;”

Proceedings of an Engineering Foundation Conference, Edited by Larry Roesner, Snowbird, Utah, August 1996.

Gustav, Richard S.; Sovern, Douglas T.; Washington, Percy M.; “If You Build It They Will Come: A Maintenance

Approach to Restoring Fish Habitat in Urban Streams Heavily Influenced by Stormwater Flows;” Proceedings of the Water

Environment Federation 661h Annual Conference & Exposition, Anaheim California, October 1993.

Kerr Wood Leidal Associates LTD., D.B. Lister & Associates LTD, Stream Enhancement Guide, Province of British

Columbia, Vancouver, British Columbia, 1980.

Leopold, Luna B., Wolman, Gordon M., Miller, John P., Fluvial Processes in Geomorphology, W. H. Freeman and

Company, San Francisco and London, 1964.

MacCrae, C. R., “Experience From Morphological Research on Canadian Streams: Is Control of the Two-Year Frequency

Runoff Event the Best Basis for Stream Channel Protection?” Proceedings of an Engineering Foundation Conference,

Edited by Larry Roesner, Snowbird, Utah, August 1996.

National Research Council, Restoration of Aquatic Ecosystems, Washington, D.C., 1992.

Rosgen, David L., “A Classification of Natural Rivers,“Catena, ElsiverScience, B.V., Amsterdam, The Netherlands, 1994.

Seattle, City of, Longfellow Creek Habitat Restoration Master Plan, Seattle, Washington, 1999.

Seattle, City of, Pipers Creek Rehabilitation, Erosion and Sedimentation Management Program and Design Manual, 1997.

Simons, Daryl B. and Senturk, Fuat, Sediment Transport Technology, Water and Sediment Dynamics, Water Resources

Publications, Littleton, Colorado, 1991.

Sovern, Douglas T. and Washington, Percy M., “Effects of Urban Growth on Stream Habitat,” Proceedings of an

Engineering Foundation Conference, Edited by Larry Roesner, Snowbird, Utah, August 1996.

Washington, Percy M., Conservation, Seattle, Washington, August 1, 1999.

80
81

Lessons Learned About Successfully Using Infiltration Practices

Eric H. Livingston

Stormwater/NPS Management Section

Florida Department of Environmental Protection

2600 Blair Stone Road (MS3570)

Tallahassee, Florida 32399-2400

Abstract

Infiltration practices are one of the most valuable urban stormwater BMPs because they not only help to reduce

stormwater pollutants but, more importantly, help to reduce stormwater volume. Unfortunately, infiltration practices have

gotten a bad reputation over the past 20 years because of their potential to fail. This paper will review the successes and

failures of the use of infiltration practices in the United States. It will summarize the lessons that have been learned about

the use of infiltration practices. This will include recommendations on when they should be used and how, and

recommendations on when they should not be used. Finally, the paper will discuss what can be done to reduce stormwater

volume when infiltration practices cannot be used successfully.

Introduction

To achieve the desired objectives of flood control, water quality protection, erosion control, improved aesthetics, and

recreation, a stormwater management system must be an integral part of the site planning for every development site.

Although the basic principles of stormwater management remain the same, each individual site and each specific project

presents unique challenges, obstacles, and opportunities. The many variations in climate, soils, geology, groundwater,

topography, vegetation, and planned land use require site-specific design. 

The natural attributes of each site will strongly influence the type and configuration of the stormwater system. These

features will suggest which particular combination of Best Management Practices (BMPs) can be successfully integrated

into an effective system. Whenever site conditions allow, the stormwater management system should be designed to

achieve maximum on-site storage of runoff by incorporating infiltration practices throughout the remaining natural and

landscaped areas of a site. A stormwater management system should be viewed as a "treatment train" in which the

individual BMPs are the cars. Generally, the more BMPs that are incorporated into the system, the better the performance

of the treatment train. Inclusion of infiltrative practices as one of the cars should be a primary goal of stormwater system

designers, even on sites where detention practices will be the primary BMP.

Infiltration practices (or retention practices) retain stormwater on-site, allowing it to soak into the ground or evaporate. There

are a number of different infiltration practices that have been widely used throughout the United States, including basins,

trenches, dry wells, pervious pavements, and swales. Often infiltration practices include vegetation with a wide variety of

trees and shrubs. In 1987, Prince George’s County, Maryland, began evolving this type of infiltration practice into

“bioretention,” which is a BMP that uses the soil matrix and vegetation to sequester pollutants within the terrestrial

environment (PGC, 1993, 1997)

Infiltration practices are one of the few BMPs that can help to assure that all four stormwater characteristics (volume,

rate, timing, and pollutant load) after development closely approximate the conditions which occurred before development.

That is because infiltration practices help to maintain pre-development site perviousness and vegetative cover, thereby

reducing stormwater volume and discharge rate, which further promotes infiltration and filtering of the runoff.

The benefits of infiltration include reducing stormwater volume and peak runoff rate; recharging groundwater, which

helps to replenish wetlands, creeks, rivers, lakes, and estuaries; augmenting base flow in streams, especially during low

flow times; settling and filtering of pollutants as they move through the system’s vegetation and surficial soils; lowering the

probability of downstream flooding, stream erosion, and sedimentation; and providing water for other beneficial uses. 
82

Another benefit of infiltration practices is their ability to serve multiple uses since they are temporary storage basins.

Recreational areas (e.g., ballfields, tennis courts, volleyball courts), greenbelt areas, neighborhood parks, and even parking

facilities provide excellent settings for the temporary storage of stormwater. Such areas are not usually in use during

periods of precipitation and the ponding of stormwater for short durations does not seriously impede their primary functions.

Longevity of Infiltration Systems

One of the problems with infiltration BMPs that has been consistently identified, either quantitatively or qualitatively,

is their high rate of failure. Maryland’s Stormwater Program produced one of the most comprehensive quantitative reviews

of the longevity of infiltration systems (Pensyl and Clement, 1987; Lindsey et al, 1992). This information is summarized

in Table 1, where it can be seen that the overall condition and functioning of infiltration systems declined over time. In

1986, about two-thirds of all surveyed facilities were functioning as designed, while in 1990, only about half were. Only 42%

of the facilities were functioning as designed in both 1986 and 1990, while about 27% were not functioning as designed in

both years. About 24% of the systems were functioning in 1986, but not in 1990; while only 7% of those not working in

1986 were working in 1990. Maintenance was needed at more facilities in 1990 (66%) than in 1986 (45%). Additionally,

38% of facilities that needed maintenance in 1986, still needed maintenance in 1990, while 32% of the facilities that did

not need maintenance in 1986, did need it in 1990. Only 10% of the systems that needed maintenance in 1986 did not need

maintenance in 1990. These data suggest that little effort is expended on maintaining the operational capabilities of

stormwater management systems.

Additional quantitative information on the success and failure of infiltration systems was collected in the Puget Sound,

Washington, area (Klochak, 1992; Gaus, 1993; Hilding, 1993; Jacobson and Horner, 1993). Of 23 infiltration basins

evaluated, 12 did not comply with the region’s guidelines for either infiltration rate or time for the basin to recover its storage

volume. Interestingly, the authors found no relationship between lack of basin maintenance and failure, with examples of

basins with and without maintenance that did not function properly. Some basins were functioning properly even though

they had never been maintained, while 43% of the 23 basins had been scarified to enhance performance.

The above data, when combined with qualitative information from Florida and Delaware (Baldwin, 1999, personal

communication), seem to indicate that infiltration basin failures are associated with:

1. Inaccurate estimation of infiltration rates

2. Inaccurate estimation of the seasonal high water table

3. Excessive compaction during the construction process

4. Excessive sediment loadings either from improper erosion and sediment control during the construction process

or a lack of pretreatment BMPs

5. Lack of maintenance

Factors Influencing Successful Use of Infiltration Systems

Factors that influence the successful use of any stormwater BMP can be categorized as institutional, technical, and

implementational. This section of the paper will examine the components of each of these categories that must be included

in a stormwater program if the causes of infiltration system failure are to be minimized.

Institutional Components

The “BMP Golden Rule” states that stormwater BMPs should never be required unless the stormwater program includes

components that will assure that the BMPs are correctly designed, approved, constructed, inspected, maintained,
83

Table 1. Results of Maryland Infiltration Practices Surveys

Basins Trenches Dry Wells Perv. Paving Veg. Swale

1986 1990 1986 1990 1986 1990 1986 1990 1986 1990

# facilities 63 48 94 88 30 25 14 13 6 3

(% of total) 30% 27% 45% 30% 14% 14% 7% 7% 3% 2%

Facility Evaluations

Functioning 30 18 75 47 23 18 7 2 3 2

48% 38% 80% 53% 77% 72% 50% 15% 50% 67%

OM Needed 41 39 28 64 9 4 10 8 6 3

65% 81% 30% 73% 30% 16% 71% 62% 100% 67%

Performance and Maintenance Criteria

Buffer strip 20 4 65 35 24 0 14 3 1 0

inadequate 32% 8^ 69% 39% 80% 100% 23% 17%

Stabilization 12 23 11 13 1 3 1 1 3 1

needed 19% 48% 12% 15% 3% 12% 7% 8% 50% 33%

Sediment 24 28 32 58 0 2 9 9 4 1

entry 38% 58% 34% 66% 8% 64% 64% 67% 33%

Inappropriate 41 25 25 20 9 3 7 4 4 0

ponding 65% 52% 27% 23% 30% 12% 50% 31% 67%

No observed na na 45 58 4 7 10 11 na na

well 45% 56% 13% 28% 71% 85%

and operated (Livingston, 1997). Specifically, the program must have stormwater treatment and management goals,

performance standards, education, and an institutional framework that includes plan approval, inspections during and after

construction, legal operation and maintenance entity requirements, effective compliance mechanisms, and dedicated

funding mechanisms. 
84

Program goals: Experience has shown that stormwater programs need to have multiple objectives that are important

to the general public in order to gain the support of the community. Typically, these will include flood protection, erosion

and sediment control during construction, water quality and habitat protection, and open space and recreation. Infiltration

systems can help achieve all of these goals.

Performance standards: Nearly all stormwater treatment programs in the United States are technology-based, relying

upon a performance standard (minimum level of treatment) and design criteria for various BMPs that assure that they

achieve the desired treatment goal. A review of 32 stormwater programs around the country showed that the most common

performance standard is removing at least 80% of the average annual loading of total suspended solids (WMI, 1997a).

Some programs require higher levels of treatment for stormwater discharges to sensitive waters, such as Florida’s

requirement that discharges to Outstanding Florida Waters remove at least 95% of the average annual pollutant load.

Technology-based performance standards such as these provide water quality goals for nonpoint sources that create equity

with the minimum treatment requirements for domestic wastewater point sources (Livingston, 1988). 

Institutional framework: The stormwater program must have a strong institutional framework that assures that all BMPs

are (1) properly designed, (2) reviewed and approved, (3) inspected during and after construction, and (4) operated and

maintained. The components of this institutional framework are set forth in Figure 1. One of the most important components

especially for infiltration practices, is a feedback mechanism among system inspectors, plan reviewers, and designers

about what is working and what is not. This information can then be used to revise the design criteria for infiltration BMPs

and improve their potential for long-term success.

Technical Components:

Successful implementation of any BMP depends on a thorough understanding of the factors that determine the BMP’s

treatment effectiveness, a strong scientific basis for the BMP’s design criteria, and an understanding of the site conditions

that are required or that limit the utility of a specific BMP. Infiltration practices are also commonly called retention practices

because they retain the runoff on-site and are designed to infiltrate a design volume (treatment volume) of stormwater.

Factors that influence the treatment effectiveness and feasibility of infiltration practices include (1) precipitation patterns,

(2) whether the system is designed as an on-line or off-line system, (3) whether pretreatment via the BMP treatment train

is provided, and (4) site characterisitcs such as land use, soil type, geology, water table elevation, topography, and

vegetation.

Infiltration areas, especially off-line ones, can be incorporated easily into landscaping or open space areas of a site.

These can include natural or excavated grassed or landscaped depressions and recreational areas. Parking lots, with their

landscape islands, offer an excellent opportunity for the use of this concept since even the infiltration of a quarter inch of

runoff will greatly reduce sediments, metals, oils and greases. Placing storm sewer inlets within recessed parking lot

landscape areas, raising the inlet a few inches above the bottom, and using curb cuts to allow runoff to enter this area

represents a highly effective treatment train. If site conditions prevent the exclusive use of infiltration, then off-line retention

areas should be used as pretreatment practices in a stormwater treatment train. This is especially true if detention lakes

are the primary component of the stormwater system and the lakes are intended to serve as a focal point of the

development.

Pollutant removal efficiency factors: Average annual pollutant removal efficiency is calculated considering the annual mass

of pollutants available for discharge and the annual mass removed. The primary removal mechanism for infiltration practices

is the volume of stormwater that is infiltrated, since this eliminates the discharge of stormwater and its associated

pollutants. In addition, the system’s vegetation and the surficial soils play an important role in binding and transforming

pollutants as the water infiltrates. As with any type of stormwater management practice, actual field efficiency will depend

on a large number of factors. For infiltration practices, such factors include:

1. Long-term precipitation characteristics; such as mean number of storms per year, their intensity and volume, and

average inter-event time.
85
86

2. The occurrence of first flush, which is related to the amount of directly connected impervious area; type of

stormwater conveyance system; and the pollutant of interest

3. Whether the system is an "on-line" or an "off-line" design 

4. Cumulatively, the above three factors determine the minimum treatment volume and maximum storage recovery

time

The U. S. Weather Bureau has measured weather statistics at many locations around the country. Long-term

precipitation records, including such information as day and duration of event, intensity, volume, etc., are available from

either the Federal government or private vendors. Statistical analysis of these records can develop probability frequencies

for storm characteristics such as the mean storm volume and the mean inter-event period between storms.

"First flush" describes the washing action that stormwater has on accumulated pollutants in the watershed. In the early

stages of runoff, the land surfaces, especially impervious ones like streets and parking areas, are flushed clean by the

stormwater. This flushing creates a shock loading of pollutants. However, the occurrence and prevalence of first flush

depends largely on precipitation patterns, the degree of imperviousness of the contributing drainage area, the size of the

drainage area, and the type of stormwater conveyance system. Florida studies have determined that for highly impervious

urban land uses with drainage areas under 100 acres, there is a first flush for many pollutants, especially particulates

(Yousef et al., 1985; Miller, 1985). In areas such as Oregon and Washington, however, where rainfall consists of low

intensity, long-duration "events," first flush is not very prevalent.

On-line stormwater practices store runoff temporarily before most of the volume is discharged to surface waters. These

systems capture all of the runoff from a design storm. This mixes all stormwater within the system, thereby masking first

flush and reducing pollutant removal. They primarily provide flood control benefits, with water quality benefits usually

secondary--although on-line wet detention systems provide both.

Off-line practices are designed to divert the more polluted first flush stormwater for water quality treatment, isolating

it from the remaining stormwater that is managed for flood control. In infiltration systems, the diverted first flush is not

discharged to surface waters, but is stored until it is gradually removed by infiltration, evaporation, and evapotranspiration.

Vegetation, such as grass in the bottom and sides of infiltration areas, helps to trap stormwater pollutants and reduce the

potential for transfer of these pollutants to groundwater. Off-line retention practices are the most effective for water quality

enhancement of stormwater.

Since an off-line retention area primarily provides for stormwater treatment, it must be combined with other BMPs for

flood protection to form a comprehensive stormwater management system. Figure 2 is a schematic of an off-line system,

commonly referred to as a "dual pond system." In these systems, a smart weir directs the first flush stormwater into the

infiltration area until it is filled, with the remaining runoff being routed to the detention facility for flood control.

A more recent investigation of the influence of long-term rainfall characteristics on the efficiency of retention practices

included inter-event dry periods, leading to the development of diversion volume curves for inter-event dry periods of varying

length (Wanielista et al., 1991a). Figure 3 shows an example diversion volume curve for the Orlando area. It is important

to note that first flush is not considered in these curves. If a first flush effect does exist, the design curves would be

conservative in that the percent treatment efficiency of the infiltration system would increase. Furthermore, these curves

are based on precipitation-interevent-frequency (PIF) curves that also include consideration of the probability that a storm

greater than the design storm will occur. The PIF analysis looked at exceedance probabilities storms with a return period

of 2, 3, 4, or 6 months, representing a chance that the storm will exceed the design volume 6, 4, 3, or 2 times per year.

Other useful products from this project are Rate-Efficiency-Volume charts and curves that can be used to design wet

detention ponds that reuse runoff and thereby help to balance pre- and post-development volume (Livingston et al., 1999).
87

Figure 2. Schematic of an Off-line Stormwater System.

Figure 3. Diversion Volume Curve for Orlando, Florida.
88

Site Characteristics: The suitability of a site for using infiltration practices will depend on a careful evaluation of the site's

natural attributes. Proposed infiltration areas should be evaluated for feasibility on any particular site or project by

examining the following:

SOILS - Must be suitable for infiltration. Nationally, most states recommend that soil textures should not have more

than 30% clay content or 40% silt content. Most importantly, they need to be able to percolate the diverted volume to

infiltrate within 72 hours, or within 24-36 hours for infiltration areas that are planted with grasses. Therefore, soils that have

been classified by the NRCS as HSG A are recommended for infiltration practices, although they can be successfully used

with HSG B soil types.

INFILTRATION RATES - In recent years, the minimum permeability rate recommended for infiltration practices has

been raised by implementing agencies. Shaver (1986) recommended a minimum rate of 0.25 inches per hour, but

Maryland’s regulations now recommend 0.52 inches per hour. One of the most difficult aspects of designing infiltration

practices is obtaining reliable information about the actual infiltration rate of the soil where the practice will be constructed.

Unfortunately, such information is not easily obtainable. Avellaneda (1985) conducted 20 hydrologic studies of vegetated

swales constructed on sandy soils with a water table at least one foot below the bottom during dry conditions. Infiltration

rates were measured using laboratory permeability tests, double ring infiltrometers, and field mass balance experiments.

The field mass balance method measured a minimum infiltration rate of 2-3 inches/hour. This measured rate was much less

than lab permeabilities, rates measured by double ring infiltrometer tests (5-20 in/hr), or rates published in the Detailed Soil

Survey. 

The following should be considered for determining the infiltration rate for retention practices:

1. Since the infiltration rate is the key to designing any retention practices, conservative estimates should be used,

and safety factors incorporated into the design to ensure that the design volume will actually be percolated into the

soil and not discharged downstream.

2. It is important that on-site infiltration measurements be taken at the locations where retention practices will be

located. More importantly, since soil characteristics and infiltration rate change with depth, it is crucial that the

measurements be made at the depth of the design elevation of the bottom of the retention practice.

3. Infiltration rates should be determined by mass balance field tests if possible. They provide the most realistic,

accurate estimate of the percolation rate. If field tests are not possible, infiltrometer tests should be used, with lab

permeability tests a third option. In either of these latter two tests, the design infiltration rate should be half of the

lowest measured rate. As a last resort, information from Detailed Soil Surveys can be used to estimated the

infiltration rate. However, the lowest rate should be used--as should a safety factor of two. 

A recent assessment of infiltration practices in Carroll County, Maryland, quantified the infiltration rates for six basins

and six trenches of differing ages (Nelson et al., 1999). They found that 64% of the systems had an average infiltration

rate below the state’s minimum recommended rate. However, 70% of the practices were still recovering their storage

volume within the required 72 hours. Interestingly, for some facilities (mainly trenches), the infiltration rate met or exceeded

the minimum state rate for a large percentage of the volume of water infiltrated, while the remaining water persisted for much

longer periods of time before infiltrating. This may indicate that (1) the infiltration rate is related to the hydraulic head, where

the higher depth of the stormwater in the BMP creates a higher pressure pushing water into the ground, or (2) the bottoms

of the systems accumulate fines that impede percolation, while the sides of the systems are still infiltrating runoff rapidly.

WATER TABLE - The seasonal high water table should be at least three feet beneath the bottom of the infiltration area

to assure that stormwater pollutants are removed by the vegetation, soil, and microbes before contacting the groundwater.

Jacobson and Horner (1993) recommend a minimum of five feet if the seasonal high water table cannot be estimated

accurately. When considering the groundwater elevation, it is important to remember that the retention area can cause a

mounding effect on the water table, thereby raising it above the predevelopment level. The Southwest Florida Water

Management District (SWFWMD) has developed a model that can be used to more accurately determine the seasonal high

water table and the effects of mounding (SWFWMD, 1998).
89

GEOLOGY - Bedrock should be at least three feet beneath the bottom of the infiltration area. In those parts of the

country where limestone is at or near the land surface, special precautions must be taken when using infiltration practices.

The potential for groundwater contamination in such areas is quite high, especially in "Karst Sensitive Areas" (KSA) where

sinkhole formation is common. In KSAs, solution pipe sinkholes may form in the bottom of infiltration areas creating a

direct conduit for stormwater pollutants to enter the groundwater. Solution pipes often open in the bottom of retention areas

because the natural soil plug capping the solution pipe is thinned by partial excavation to create the retention area and

because the stormwater creates a hydraulic pressure which can wash out the plug.

In KSAs, a site-specific hydrogeologic investigation should be undertaken that includes geologic borings wherever

infiltration areas are proposed and mapping limerock outcroppings and sinkholes on site. Infiltration systems in KSAs

should (1) include several small off-site areas, (2) use swale conveyances for pretreatment, (3) be as shallow as possible,

(4) be vegetated with a permanent cover such as sodded grasses, and (5) have flat bottoms to keep the stormwater spread

out across the entire area.

TOPOGRAPHY - Infiltration practices should not be located on areas with slopes over 20% to minimize the chance

of downstream water seepage from the subgrade. Sloping sites often require extensive cut and fill operations. Infiltration

practices should not be sited on fill material, since fill areas are very susceptible to slope failure, especially when the

interface of the fill/natural soil becomes saturated.

VEGETATION - To reduce the potential for stormwater pollutants to enter groundwater, and to help maintain the soil's

capacity to absorb water, infiltration practices should be vegetated with appropriate native vegetation, especially grasses.

However, this type of vegetation cannot tolerate long-term inundation, so the retention area must be capable of infiltrating

all of its runoff within a relatively short time period (i.e., 24 to 36 hours). The design of “bioretention” systems incorporates

soils and vegetation that are proficient in trapping stormwater pollutants within them and takes advantage of microbial

processes that help transform and trap pollutants in the terrestrial environment.

SET BACKS - Infiltration areas should be located at least 100 feet from any water supply well and at least 12 feet downgradient from any building foundations. Additionally, they should be set back at least 50 feet from on-site wastewater

systems, especially drain fields.

LAND USE RESTRICTIONS - Certain infiltration practices can only be applied to particular land uses. For example,

some sites are so small or intensively developed that space is insufficient for surficial practices (e.g., retention basin), but

they may allow for infiltration or exfiltration trenches if pretreatment can be provided. A concern with any infiltration practice

is the potential for hazardous or toxic wastes to enter the system and migrate into the groundwater. Land uses where such

substances are used should implement comprehensive pollution prevention, spill containment, and emergency response

plans that will prevent dangerous materials from getting into the infiltration system. 

POTENTIAL FOR GROUNDWATER POLLUTION - A possible concern about infiltration practices is whether they

simply are transferring the stormwater pollution problem from surface waters to groundwaters. Stormwater pollutants,

especially heavy metals, quickly bind to soil particles and vegetation is effective in filtering pollutants, thereby minimizing

the risk of groundwater contamination (Harper, 1985; Yousef et al, 1985b). However, groundwater beneath swales, and

retention areas located in highly sandy soils with low organic content, did show elevated levels of heavy metals down to

depths of 20 feet (Harper, 1988).

Design Criteria

Once all of the above factors have been quantified using state, regional, or local data as appropriate, specific design

criteria can be established. Table 2 summarizes the design criteria for infiltration systems set forth in Florida’s stormwater

regulations. St. John’s River Water Management District (SJRWMD, 1992).
90

L

KQ S

n i

5/8 3/16

3/8

=

Table 2. Florida’s Design Criteria for Infiltration Practices

BMP 80% Treatment Effectiveness Diversion Volume

Swales Infiltrate 80% of the runoff from a 3-yr, 1-hr storm (2.5 inches)

Retention - Off-line Infiltrate the larger of 0.5 inches of runoff or 1.25" X % impervious

Retention - On-line Infiltrate an additional 0.5 inches of runoff

DESIGN FACTOR CRITERIA

Soil type HSG A or B with < 30% clay or < 40% silt/clay

Treatment volume recovery time 72 hours, 24 to 36 hours if grassed

Water table or bedrock At least 3 feet beneath bottom after mounding

Topography On slopes < 20%, not on fill soils

Vegetation Recommended to reduce potential for groundwater pollution and to maintain soil permeability

Land use May not be appropriate at sites where hazardous materials spills may occur

Swales: Traditionally, swales are used primarily for stormwater conveyance and, as such, are considered an on-line

practice. The removal of stormwater pollutants by swales can occur by infiltration or vegetative filtration. Investigations

in Florida (Yousef et al., 1985a; Harper, 1985) have concluded that swale treatment efficiency largely depends on the

volume of stormwater that can be infiltrated through the filtering vegetation and into the soil. 

Avellaneda (1985) developed the following equation for a triangular-shaped swale to estimate the length of swale

necessary to infiltrate the design stormwater treatment volume: 

where:

 L = swale length (m) n = Mannings roughness coefficient

 Q = average runoff flow rate (m3/S) i = infiltration rate (cm/hr)

 S = longitudinal slope (m/m) 

 K = constant which is a function of side slope that varies from 4,722 to 10,516

For most residential, commercial, and highway projects, the length of swales necessary to percolate the stormwater

needed to achieve the 80% performance standard was found to be excessive, or at least twice the distance available.

Thus, some type of swale block (berm) or on-line detention/retention may be more helpful. Swales make excellent

pretreatment practices by providing for the infiltration of some stormwater and for some vegetative filtration. By using a

raised storm sewer inlet, swales can provide water quality enhancement via retention and still serve as effective

conveyances for flood protection. Swales can incorporate retention by using swale blocks, small check dams, or elevated

driveway culverts to create storage; thereby reducing runoff velocity, reducing erosion, and promoting infiltration. In

highway designs for high speed situations, safety must be considered; thus, a maximum depth of water equal to 1.5 feet

and flow line slopes on the berms of 1 vertical/20 horizontal are recommended. Along lower speed highways or in some

residential/commercial urban settings, steeper flow line berm slopes (1 on 6) are acceptable (Wanielista et.al., 1986).

Unlike Florida, investigations in Washington State (Horner, 1988; WPCD, 1992) indicate that swales can also act as

a biofilter, with removal of particulate pollutants without infiltration of stormwater. The following recommendations were made

to improve their water quality benefits: 

1. Maximum design velocity should not exceed 27 cm per second.
91

2. A hydraulic residence time of at least 9 minutes is recommended for removal of about 80% of the total suspended

solids. Longer residence times will provide higher removal effectiveness.

3. Swale width should be limited to 6 to 8 feet, unless special measures are provided to assure a level swale bottom,

uniform flow spreading, and management of flows to prevent formation of low-flow channels.

4. Swale slopes should be between 2 and 4%.

5. Water depth should be limited to no greater than one half the height of the grass, up to a maximum of 3 inches of

water depth.

6. Swale length will be a function of the hydraulic residence time, swale width, and stormwater volume and velocity.

Implementation Components

Even if effective design criteria have been established for an infiltration system, the design has been reviewed and

approved, and the institutional framework to assure performance has been established, an infiltration system may still not

work correctly. In fact, assessments of the success or failure of infiltration systems have determined that poor construction

is a major factor in system failure (Pensyl and Clement, 1987; Lindsey et al., 1991). We will discuss five considerations

that are essential to proper implementation of infiltration practices including (1) education, (2) erosion and sediment control,

(3) construction, (4) inspections, and (5) maintenance. 

Education: The stormwater program needs to include an extensive education program that targets BMP designers,

plan reviewers, inspectors, contractors, and maintenance personnel. Each of these practitioners is an important part of

the stormwater team. They must each understand their role in BMP design and implementation, as well as the technical

factors discussed above. Additionally, a communication mechanism needs to be established among all of these

practitioners so that in-the-field knowledge of what works, and what does not work, is transferred back to all other team

members. With respect to BMP installation, the plan reviewers and inspectors should meet with the project engineers and

contractors on-site to review the site plan, construction sequencing, erosion and sediment control plan and details, and the

infiltration system’s detailed standards and specifications.

Erosion and sediment control: Infiltration practices must be protected from sediment loadings, especially during the

project’s construction phases. Infiltration practices should never be used as part of the erosion and sediment control

system, nor should they be put into operation until all contributing drainage areas are fully stabilized. Although sediment

loads drop sharply after construction is completed, gradual clogging of infiltration practices can still occur. Pre-treatment

practices such as swale conveyances or vegetated buffer strips can help to filter out sediments and extend the life of

retention practices. Do not forget the treatment train concept.

Construction considerations: To prevent clogging of infiltration areas, special precautions must be taken during the

entire construction phase of a project to prevent reduction of the system’s infiltration capacity. In particular, two areas need

to be stressed, including preventing sedimentation during construction and preventing compaction of the soil. Areas that

are selected for infiltration use should be well marked during site surveying and protected during construction. Specifical

construction recommendations are as follows (WMI, 1997b): 

1. If possible, schedule construction so it does not occur during the rainy season but does occur during the vegetation

growing season. For example, in Auckland, New Zealand, construction sites are shut down during the winter when

long, prolonged rains make erosion and sediment controls ineffective and when vegetation does not 

grow well. Unfortunately, in the United States, these seasons often overlap and the economics of development

dictate the time frame for starting construction. 

2. Before the development site is graded, areas planned for use as infiltration systems should be well marked during

site surveying, and all traffic and heavy equipment kept away from the area to prevent compacting the underlying

soils.
92

3. Construction should be overseen by someone who is trained and experienced in the installation of infiltration

practices, and who is knowledgeable about their purpose and operation.

4. The design team should inspect the exposed soil after excavation to confirm that soil conditions are as expected

and are suitable for the approved design. If they are not, work should not proceed and the situation should be

analyzed to determine whether or not design or construction changes should be made to the approved design.

5. Construction of the infiltration system should not begin until after the site has been completely stabilized. If this

is not possible, then:

a. Diversion berms should be placed around the perimeter of the infiltration area during all phases of construction

to divert runoff and sediment away from it.

b. Sediment and erosion control plans for the site should be oriented to keep sediment and runoff completely away

from the area.

c. The facility should not be excavated to final grade until after the contributing drainage area is stablilized. Leave

at least two feet of native soil during the initial excavation. 

6. Infiltration areas should never be used as a temporary sediment basins during the construction phase.

Unfortunately, it is common for infiltration areas, especially basins, to be used as a sediment trap, with initial

excavation to within two feet of the final design elevation of the basin floor. If the facility is to be used during

construction, this soil can be removed in layers as it clogs. Once construction is completed, sediment that

accumulated during the construction phase can then be removed when the basin undergoes final excavation to its

design elevation. However, recent experience indicates that even with this type of construction practice, infiltration

areas used as sediment traps have a higher rate of failure.

7. Infiltration areas/basins should be excavated using light earth-moving equipment with tracks or over-sized tires.

Normal rubber tires should be avoided since they compact the subsoil and reduce its infiltration capabilities. For

the same reason, the use of bulldozers or front end loaders should be avoided. 

8. During construction, place excavated material at least 10-15 feet away from the infiltration area.

9. Since some compaction of the underlying soils is still likely to occur during excavation, the floor of the basin should

be deeply tilled with a rotary tiller or disc harrow at the end of the excavation process.

10. Rock used in infiltration or exfiltration trenches should be washed clean of sediments. Rock should be placed in

lifts and compacted after each lift.

11. Trenches should be clear of any protruding objects and carefully inspected before installing geotextile fabrics. The

fabrics should have the proper permeability and be installed with at least a 12-inch overlap, in a shingle-like manner

12. Trenches should be covered and not put into operation until the contributing drainage area is completely stabilized

and all pretreatment BMPs installed. 

13. Pervious asphalt and concrete should be installed only by certified personnel who are specifically trained in their

batching, pouring, and finishing.

14. The basin should be stabilized with vegetation within a week after construction. Use of low maintenance, rapidly

germinating native grasses are recommended. The condition of the newly established vegetation should be

checked several times over the first two months, and any necessary remedial actions taken (e.g., reseeding,

fertilization, and irrigation).
93

Inspections: Like all stormwater treatment practices, infiltration systems need to be inspected during construction and

on a regular basis after construction. Inspections during construction are needed to assure that the infiltration system is

built in accordance with the approved design and standards and specifications. Five inspections are recommended: (1)

pre-construction, (2) during excavation, (3) during construction of the embankment (if applicable), (4) after final excavation,

and (5) after construction is completed. During this final inspection, the inspector should have a copy of the “As-built or

record drawings.” In addition, infiltration systems should be inspected semi-annually after construction (before and after

wet seasons) to ensure that they continue to function. Two site trips are recommended: one during or immediately after

a rainfall, so that conditions during operation can be observed, and a second from 24 to 72 hours after the rainfall, to

determine whether the system is recovering its storage volume as designed. Inspection forms are highly recommended.

Examples of inspection forms (WMI, 1997b) can be downloaded from the EPA web site located at

http://www.epa.gov/owow/NPS/orderform.html.

Maintenance: All infiltration practices will require regular and non-routine maintenance to maintain their ability to

infiltrate stormwater. The frequency and need for maintenance will depend primarily on the loading of particulates and

whether pre-treatment practices have been employed. Routine maintenance includes revegetating eroding areas, removing

materials that accumulate in pretreatment BMPs, and removing materials from inlets and outlets. Non-routine, restorative

maintenance activities should be conducted whenever inspections reveal that stormwater remains in the system beyond

the designed time. These may include structural repairs to the inlets or outlets and restoration of the infiltration capability

of the system. 

Additional Concerns and Recommendations

Concerns with Pervious Pavement: Local land development codes typically specify the type of material for a parking

lot (i.e., paved, grass, gravel) and determine the number and size of parking spaces within a parking lot. These

requirements should be reviewed carefully to ensure that they are necessary (is paving really required in every case) and

that the number of spaces is related to actual traffic demands. After these requirements have been reviewed and verified,

the use of pervious pavement within a parking lot should be examined. Pervious pavement materials include pervious

asphalt, pervious concrete, turf blocks, and even Geoweb covered with sod.

Overall, experiences with pervious pavements have not been very good. Pervious pavements have been prone to

clogging. Causes include poor erosion and sediment control during construction, unstabilized drainage areas after

construction, improper mixing and finishing of the pavement, and poor maintenance. However, field investigations of

pervious concrete that has been in use for up to 15 years in Florida indicate that these parking lots can continue to infiltrate

rainfall and runoff if they were installed and maintained properly (FCMA, undated). Pervious concrete not only helps reduce

site imperviousness, but also reduces hydroplaning and road noise. 

Recommendations: Specific recommendations and other important information about infiltration systems that will help

increase their successful implementation are summarized in Table 3. This table includes essential information about the

advantages, disadvantages, maintenance, and other aspects of successfully using infiltration practice. To improve

evaluation of site conditions for the suitability of infiltration practices, Jacobson and Horner (1993) recommended a quan

titative rating system. The factors used in the system included: (1) soil till layer (presence and location), (2) location of

seasonal high water table, (3) removal efficiency of the pretreatment BMPs, (4) degree of siltation protection, (5) soil type,

and (6) infiltration rate. Different degrees of acceptability are possible: (1) disqualifying (characteristics that eliminate design

or location from further consideration), (2) passable (characteristics that allow consideration but not ideal), and (3) ideal

(optimum characteristics for design or siting of facility). Table 4 illustrates the proposed rating system factors. 
94

Table 3. Additional Information About Infiltration Systems to Enhance Successful Implementation

Infiltration

Bmp Type Advantages Disadvantages Maintenance Comments

Surface Basin •Integrate into land- •Land area required •Vegetated basins should be •Can serve larger drainage

(Typically recessed scaping, open space, •Potential mosquito mowed and clippings removed 3:1 or flatter side slopes, flat

areas or, in Mid-Atlantic parking lot islands problem if not designed •Remove sediments when dry bottom

States, rock filled) •Use for recreation or maintained properly and cracked •Bottom and side slope vege-

•Easier inspection and •Non-vegetated basins require tation recommended

maintenance annual disking

Infiltration Trench •Can be used where •Easily clogged •Removing sediments that •Pretreatment essential

(Typically a rock filled land or space is limited •Difficult to unclog accumulate in rocks •Use observation well

trench) •Difficult to monitor •Keep covered until drainage

performance area stabilized

Exfiltration Trench •Can be used where •Easily clogged •Remove materials that enter •Pretreatment essential

(Typically a perforated land or space is •Difficult to unclog pipe •Source controls useful

pipe with a gravel limited •Difficult to monitor •High pressure wash perforated •Geotextile is limiting infiltraenvelope) performance pipe tion factor

•Removing sediments that •Inf. rate 0.5"/hr if use sides

Accumulate in rocks, replace and bottom

rocks •Inf. rate 1"/hr if use bottom

Pervious Pavement •Reduces impervious- •Easily clogged •Regular vacuum street •Proper batching and placeness •Lack of trained sweeping ment is crucial

•Reduces hydroplaning practitioners •High pressure cleaning •Education programs needed

and highway noise •Anaerobic conditions •Drilling holes to restore for practitioners

•Higher recharge rates may develop in soils infiltration •Post signs to inform users 

•Replacement and keep dir and mud out

Swale (Typically •Can be incorporated •Not for flood control •Mow and remove grass •Wet swales (wetland plants)

a shallow, grassed into site ‘s landscaping/ •May “disappear” from clippings work great too

conveyance system) open areas residential back yards •Hydroscope accumulated •Use swale blocks, raised

•Great car in BMP Train •May become depository sediments and resod driveway culverts to retain

•Aesthetically pleasing for trash, yard wastes •Repair erosion areas runoff

Table 4. Possible Rating System to Evaluate the Suitability of Infiltration BMPs

Disqualifying Passable Ideal

Factor Characteristic Characteristic Characteristic

Soil till layer Impenetrable, thick layer Layer present but at >5' depth, or No till layer present

near surface easily penetrable

Seasonal High Water Close to surface, within 5' At intermediate depth, at least 5' below Very deep, well below

Table BMP bottom BMP bottom

Pretreatment None provided Some,minimum 50% TSS removal Pretreatment provides >80% 

TSS removal

Siltation None provided Any silt or construction sediment Fully protected from silt during

Protection removed before final BMP construction construction

Soils Saturated or with >30% clay Coarse, highly infiltrative soil that can be Loam or loamy sand

or >40% silt/clay content modified to produce proper inf. rate

Infiltration Rate <0.5"/hr >2.5"/hr but with very deep water table 0.5 to 2.5"/hr

or modified to slower rate
95

References

Avellaneda, Eduardo. Hydrologic Design of Swales. M.S. Thesis, University of Central Florida, Orlando, FL December

1985.

Florida Concrete Manufacturers Association. Portland Cement Pervious Pavement Manual. FCPMA, 649 Vassar Street,

Orlando, FL, 32804. No date.

Gaus, J. J. Soils of Stormwater Infiltration Basins in the Puget Sound Region: Trace Metal Form and Concentration and

Comparison to Washington State Department of Ecology Guidelines. M. S. Thesis. College of Forest Resources, U. of

Washington, Seattle, WA 1993.

Harper, Harvey H. Effects of Stormwater Management Systems on Ground Water Quality. Final Report, Contract WM-190,

Submitted to Florida Dept. of Environmental Regulation, Tallahassee, FL 1988.

Harper, Harvey H. Fate of Heavy Metals from Highway Runoff in Stormwater Management Systems. Ph.D. Dissertation,

University of Central Florida, Orlando, FL 1985.

Hilding, K. A Survey of Infiltration Basins in the Puget Sound Area. Non-thesis paper, Dept. of Biological and Agricultural

Engineering, University of California, Davis, CA 1993.

Horner, R.R. Biofiltration Systems for Storm Runoff Water Quality Control. Final Report Submitted to City of Seattle, WA

1988.

Jacobson, M.A. and R.R. Horner. Summary and Conclusions from Applied Research on Infiltration Basins and

Recommendations for Modifying the Washington Department of Ecology Stormwater Management Manual for the Puget

Sound Basin. Submitted to Urban Nonpoint Management Unit, WDOE, Seattle, WA 1993

Klochak, J.R. An Investigation of the Effectiveness of Infiltration Systems in Treating Urban Runoff. M.S.E. Thesis,

Department of Civil Engineering, University of Washington, Seattle, WA 1992.

Lindsey, G., L. Roberts and W. Page. Inspection and Maintenance of Infiltration Facilities. J. Soil Water Conserv. 47 (6):

481-186. 1992.

Livingston, E.H. State Perspectives on Water Quality Criteria. In: Design of Urban Runoff Controls, an Engineering

Foundation Conference, Potosi, MO 1988.

Livingston, E.H. Successful Stormwater Management: Selecting and Putting the Puzzle Pieces Together. In: Proc. Future

Directions for Australian Soil and Water Management, September 9 - 12, 1997, Brisbane, Australia 1997.

Livingston, E.H. M.P. Wanielista, J. Bradner. Stormwater Reuse: An Added Benefit of Wet Detention Systems. In:

Proceedings of the First South Pacific Conference on Comprehensive Stormwater and Aquatic Ecosystem Management,

Auckland, New Zealand, 1999.

Miller, R.A. Percentage Entrainment of Constituent Loads in Urban Runoff, South Florida. USGS WRI 84-4329. 1985.

Nelson, S., T. Devilbiss, and E. Bolton. Assessment of Stormwater Management Infiltration Practices in Carroll County,

MD Final Report. March 15, 1999.

Pensyl, L.K. and P.F. Clement. Results of the State of Maryland Infiltration Practices Survey. Presented at the State of

Maryland Sediment and Stormwater Management Conference, Washington College, Chestertown, MD August 1987.

Prince George’s County, Maryland. Bioretention Manual. Dept. of Env. Resources. 1993.
96

Prince George’s County, Maryland. Low-Impact Design Manual. Dept. of Env. Res. 1997.

St. Johns River Water Management District. Rule 40C-42 and associated Applicant's Handbook. Palatka, FL 1992.

Shaver, H. Earl. Infiltration as a Stormwater Management Component. In: Proceedings of the Urban Runoff Technology,

Engineering Foundation Conference, Henniker, NH 1986,

Southwest Florida Water Management District. Methods for Identifying Soils and Determining Seasonal High Ground Water

Elevations. Handout Literature for Technical Training Workshops. Brooksville, FL. 1998.

U.S. EPA, "Results of the Nationwide Urban Runoff Program: Volume 2: Final Report", Washington, DC, 1983.

Wanielista, M.P. Quality Considerations in the Design of Holding Ponds, Stormwater Retention/Detention Basins Seminar,

University of Central Florida, Orlando, FL 1977.

Wanielista, M.P., Y.A. Yousef, L. M. Van DeGroaff and S.H. Rehmann-Koo. Best Management Practices - Enhanced

Erosion and Sediment Control Using Swale Blocks. Final Report, FL-ER-35-87, Submitted to Florida Dept. of Transportation,

Tallahassee, FL 1986b.

Wanielista, M.P., M.J. Gauthier, and D.L. Evans. Design and Performance of Exfiltration Systems. Final Report, Contract

C3331, Submitted to the Florida Dept. of Transportation, Tallahassee, FL 1991a.

Wanielista, M.P., Y.A. Yousef, G.M. Harper, T.R. Lineback, and L. Dansereau. Precipitation, Inter-Event Dry Periods, and

Reuse Design Curves for Selected Areas of Florida. Final Report, Contract WM- Submitted to the Florida Dept.

Environmental Regulation, Tallahassee, FL 1991b.

Water Pollution Control Dept. Biofiltration Swale Performance, Recommendations, and Design Considerations. Publication

657, Seattle, WA 1992. 

Watershed Management Institute, Inc. Institutional Aspects of Urban Runoff Management: A Guide for Program

Development and Implementation. Cooperative Agreement with the Nonpoint Source Control Branch, U.S. EPA,

Washington, D.C. 1997a.

Watershed Management Institute, Inc. Operation, Maintenance, and Management of Completed Stormwater Management

Systems. Cooperative Agreement with the Nonpoint Source Control Branch, U.S. EPA, Washington, D.C. 1997b.

Yousef, Y.A., M.P. Wanielista, H.H. Harper, D.B. Pearce and R.D. Tolbert. Best Management Practices - Removal of

Highway Contaminants by Roadside Swales. Final Report, Submitted to the Florida Dept. of Transportation, Tallahassee,

FL 1985a.

Yousef, Y.A., M.P Wanielista, and H. Harper. Fate of Pollutants in Retention/Detention Ponds. In: Stormwater

Management: An Update. Publication 85-1, University of Central Florida, Orlando, FL. 1985b.
Potential New Tools for the Use of Tracers to Indicate Sources of

Contaminants to Storm Drainage Systems

Robert Pitt, Melinda Lalor, Jennifer Harper, and Christy Nix

Department of Civil and Environmental Engineering

The University of Alabama at Birmingham

Donald Barbe’

Department of Civil and Environmental Engineering

The University of New Orleans

Abstract

This paper is a description of previously developed methods used to identify sources of contaminants in storm

drainage systems, plus a review of emerging techniques that may also be useful. The original methods, along with

selected new procedures, were tested using almost 700 stormwater samples collected from telecommunication manholes

from throughout the U.S. About 10% of the samples were estimated to be contaminated with sanitary sewage, using these

methods, similar to what is expected for most stormwater systems. The original methods are still recommended as the

most useful procedure for identifying contamination of storm drainage systems, with the possible addition of specific tests

for E. coliand enterococci and UV absorbance at 228 nm. Most newly emerging methods require exotic equipment and

unusual expertise and are therefore not very available, especially at low cost and with fast turn-around times for the

analyses. These emerging methods may therefore be more useful for special research projects than for routine screening

of storm drainage systems.

Introduction

Urban stormwater runoff includes waters from many other sources which find their way into storm drainage systems,

besides from precipitation. There are cases where pollutant levels in storm drainage are much higher than they would

otherwise be because of excessive amounts of contaminants that are introduced into the storm drainage system by

various non-stormwater discharges. Additionally, baseflows (during dry weather) are also common in storm drainage

systems. Dry-weather flows and wet-weather flows have been monitored during numerous urban runoff studies. These

studies have found that discharges observed at outfalls during dry weather were significantly different from wet-weather

discharges and may account for the majority of the annual discharges for some pollutants of concern from the storm

drainage system.

There have been numerous methods used to investigate inappropriate discharges to storm drainage systems. Pitt,

et al. (1993) and Lalor (1994) reviewed many of these procedures and developed a system that municipalities could use

for screening outfalls in residential and commercial areas. They are currently updating these earlier methods under

funding from the U.S. EPA and the University of New Orleans. In these areas, sewage contamination, along with low-rate

discharges from small businesses (especially laundries, vehicle repair shops, plating shops, etc.) are of primary concern.

One of the earliest methods used to identify sewage contamination utilized the ratio of fecal coliform to fecal strep.

bacteria. This method is still in use, but unfortunately has proven inaccurate in most urban stormwater applications The

following discussion reviews the methodology developed by Pitt, et al. (1993) and Lalor (1994), and some new

approaches that were investigated.

Use of Tracers to Identify Sources of Contamination in Urban Drainage Systems

This research investigated inappropriate discharges into storm drainage systems. It was of most concern to identify toxic

or pathogenic sources of water, typically raw sewage or industrial wastewaters, that were being discharged accidentally

into the storm drainage system.

97
Investigations designed to determine the contribution of urban stormwater runoff to receiving water quality problems

have led to a continuing interest in inappropriate connections to storm drainage systems. Urban stormwater runoff is

traditionally defined as that portion of precipitation which drains from city surfaces and flows via natural or man-made

drainage systems into receiving waters. In fact, urban stormwater runoff also includes waters from many other sources

which find their way into storm drainage systems. Sources of some of this water can be identified and accounted for by

examining current National Pollutant Discharge Elimination System (NPDES) permit records for permitted industrial

wastewaters that can be legally discharged to the storm drainage system. However, most of the water comes from other

sources, including illicit and/or inappropriate entries to the storm drainage system. These entries can account for a

significant amount of the pollutants discharged from storm sewerage systems (Pitt and McLean 1986).

Permits for municipal separate storm sewers include a requirement to effectively prohibit problematic non-stormwater

discharges, thereby placing emphasis on the elimination of inappropriate connections to urban storm drains. Section

122.26 (d)(l )(iv)(D) of the rule specifically requires an initial screening program to provide means for detecting high levels

of pollutants in dry weatherflows, which should serve as an indicator of illicit connections to the storm sewers. To facilitate

the application of this rule, the EPA’s Office of Research and Development’s Storm and Combined Sewer Pollution

Control Program and the Environmental Engineering & Technology Demonstration Branch, along with the Office of

Water’s Nonpoint Source Branch, supported research for the investigation of inappropriate entries to storm drainage

systems (Pitt, et al. 1993). The approach presented in this research was based on the identification and quantification

of clean baseflow and the contaminated components during dry weather. If the relative amounts of these components

are known, the importance of the dry weather discharge can be determined.

The ideal tracer to identify major flow sources should have the following characteristics:

l Significant difference in concentrations between possible pollutant sources;

. Small variations in concentrations within each likely pollutant source category;

l A conservative behavior (i.e., no significant concentration change due to physical, chemical or

biological processes); and,

l Ease of measurement with adequate detection limits, good sensitivity and repeatability.

In order to identify tracers meeting the above criteria, literature characterizing potential inappropriate entries into storm

drainage systems was examined. Several case studies that identified procedures used by individual municipalities or

regional agencies were also examined.

Parameters Suitable for Indicators of Contamination by Sanitary Sewage

Tracer Characteristics of Local Source Flows. Table 1 is a summary of tracer parameter measurements for

Birmingham, Alabama. This table is a summary of the “library” that describes the tracer conditions for each potential

source category. The important information shown on this table includes the median and coefficient of variation (COV)

values for each tracer parameter for each source category. Appropriate tracers are characterized by having significantly

different concentrations in flow categories that need to be distinguished. In addition, effective tracers also need low COV

values within each flow category. The study indicated that the COV values were quite low for each category, with the

exception of chlorine, which had much greater COV values. Chlorine is therefore not recommended as a quantitative

tracer to estimate the flow components. Similar data must be collected in each community where these procedures are

to be used. Recommended field observations include color, odor, clarity, presence of floatables and deposits, and rate

of flow, in addition to the selected chemical measurements.

Simple Data Evaluation Methods to Indicate Sources of Contamination

lncficators h-plying Contamination. Indicators of contamination (negative indicators) are clearly apparent visual or

physical parameters indicating obvious problems and are readily observable at the outfall during the field screening

98
Table 1. Tracer Concentrations Found in Birmingham, Alabama, Waters (Mean, Standard Deviation and Coefficient of Variation)

Spring Treated Laundry Sanitary

water potable water wastewater wastewater

Septic

tank

effluent

Car wash Radiator

water water

Fluorescence

(% scale)

Potassium

OWL)

Ammonia

OWL)

Ammonia/Potassium

(ratio)

Fluoride

@w/L)

Toxicity

(% light decrease after

25 minutes, 12J

Surfactants

(mg/L as MBAS)

Hardness

bv3U

PH

(pH units)

Color

(color units)

Chlorine

O-w4

Specific conductivity

bS/cm)

6.8 4.6 1020 250 430 1200 22,000

2.9 0.35 125 50 100 130 950

0.43 0.08 0.12 0.20 0.23 0.11 0.04

0.73 1.6 3.5 6.0 20 43 2800

0.070 0.059 0.38 1.4 9.5 16 375

0.10 0.04 0.11 0.23 0.47 0.37 0.13

0.009 0.028 0.82 10 90 0.24 0.03

0.016 0.006 0.12 3.3 40 0.066 0.01

1.7 0.23 0.14 0.34 0.44 0.28 0.3

0.011 0.018 0.24 1.7 5.2 0.006 0.011

0.02 0.006 0.050 0.52 3.7 0.005 0.011

2.0 0.35 0.21 0.31 0.71 0.86 1.0

0.031 0.97 33 0.77 0.99 12 150

0.027 0.014 13 0.17 0.33 2.4 24

0.87 0.02 0.38 0.23 0.33 0.20 0.16

<5 47 99.9 43 99.9 99.9 99.9

n/a 20 <l 26 Cl Cl <l

n/a 0.44 n/a 0.59 n/a n/a n/a

co.5 <0.5 27 1.5 3.1 49 15

n/a n/a 6.7 1.2 4.8 5.1 1.6

n/a n/a 0.25 0.82 1.5 0.11 0.11

240 49 14 140 235 160 50

7.8 1.4 8.0 15 150 9.2 1.5

0.03 0.03 0.57 0.11 0.64 0.06 0.03

7.0 6.9 9.1 7.1 6.8 6.7 7.0

0.05 0.29 0.35 0.13 0.34 0.22 0.39

0.01 0.04 0.04 0.02 0.05 0.03 0.06

<l c l 47 38 59 220 3000

n/a n/a 12 21 25 78 44

n/a n/a 0.27 0.55 0.41 0.35 0.02

0.003 0.88 0.40 0.014 0.013 0.070 0.03

0.005 0.60 0.10 0.020 0.013 0.080 0.016

1.6 0.68 0.26 1.4 1.0 1.1 0.52

300 110 560 420 430 485 3300

12 1.1 120 55 311 29 700

0.04 0.01 0.21 0.13 0.72 0.06 0.22

Number of samples 10 10 10 36 9 10 10

activities. These observations are very important during the field survey because they are the simplest method of

identifying grossly contaminated dry-weather outfall flows. The direct examination of outfall characteristics for unusual

conditions of flow, odor, color, turbidity, floatables, deposits/stains, vegetation conditions, and damage to drainage

structures is therefore an important part of these investigations. Table 2 presents a summary of these indicators, along

with narratives of the descriptors to be selected in the field.

99
Table 2. Interpretations of Physical Observation Parameters and Likely Associated Flow Sources

Odor - Most strong odors, especially gasoline, oils, and solvents, are likely associated with high responses on the toxicity screening test. Typical obvious

odors include: gasoline, oil, sanitary wastewater, industrial chemicals, decomposing organic wastes, etc.

sewage: smell associated with stale sanitary wastewater, especially in pools near outfall.

sulfur (“rotten eggs”): industries that discharge sulfide compounds or organics (meat packers, canneries, dairies, etc.).

oil and gas: petroleum refineries or many facilities associated with vehicle maintenance or petroleum product storage.

rancid-sour: food preparation facilities (restaurants, hotels, etc.).

Color - Important indicatorof inappropriate industrial sources. Industrial dry-weather discharges may be of any color, but darkcolors, such as brown, gray,

or black, are usually of most common.

yellow: chemical plants, textile and tanning plants.

brown: meat packers, printing plants, metal works, stone and concrete, fertilizers, and petroleum refining facilities.

green: chemical plants, textile facilities.

red: meat packers.

gray: dairies.

Turbidity - Often affected by the degree of gross contamination. Dry-weather industrial flows with moderate turbidity can be cloudy, while highly turbid

flows can be opaque. High turbidity is often a characteristic of undiluted dry-weather industrial discharges.

cloudy: sanitary wastewater, concrete or stone operations, fertilizer facilities, automotive dealers.

opaque: food processors, lumber mills, metal operations, pigment plants.

Floatable Matter - A contaminated flow may contain floating solids or liquids directly related to industrial or sanitary wastewater pollution. Floatables of

industrial origin may include animal fats, spoiled food, oils, solvents, sawdust, foams, packing materials, or fuel.

oil sheen: petroleum refineries or storage facilities and vehicle service facilities.

sewage: sanitary wastewater.

Deposits and Stains - Refer to any type of coating near the outfall and are usually of a dark color. Deposits and stains often will contain fragments of

floatable substances. These situations are illustrated by the grayish-black deposits that contain fragments of animal flesh and hair which oflen are

produced by leather tanneries, or the white crystalline powder which commonly coats outfalls due to nitrogenous fertilizer wastes.

sediment construction site erosion.

oily petroleum refineries or storage facilities and vehicle service facilities.

Vegetation -Vegetation surrounding an outfall may show the effects of industrial pollutants. Decaying organic materials coming from various food product

wastes would causean increase in plant life, while the dischargeof chemical dyes and inorganicpigmentsfrom textile mills could noticeably decrease

vegetation. It is important not to confuse the adverse effects of high stormwater flows on vegetation with highly toxic dry-weather intermittent flows.

excessive growth: food product facilities.

inhibitedgrowth: high stormwater flows, beverage facilities, printing plants, metal product facilities, drug manufacturing, petroleum facilities, vehicle

service facilities and automobile dealers.

Damage to Outfall Structures - Another readily visible indication of industrial contamination. Cracking, deterioration, and spalling of concrete or peeling

of surface paint, occurring at an outfall are usually caused by severely contaminated discharges, usually of industrial origin. These contaminants are

usuallyveryacidicor basic in nature. Primaly metal industries have a strong potential forcausing outfall structural damage because their batch dumps

are highly acidic. Poor construction, hydraulic scour, and old age may also adversely affect the condition of the outfall structure.

concrete cracking: industrial flows

concrete spalling: industrial flows

peeling paint industrial flows

metal corrosion: industrial flows

Correlation tests were conducted to identify relationships between outfalls that were known to have severe

contamination problems and the negative indicators (Lalor 1994). Pearson correlation tests indicated that high turbidity

and obvious odors appeared to be the most useful physical indicators of contamination when contamination was defined

by toxicity and the presence of detergents. High turbidity was noted in 74% of the contaminated source flow samples, This

represented a 26% false negative rate (indication of no contamination when contamination actually exists), if one relied

on turbidity alone as an indicator of contamination. High turbidity was noted in only 5% of the uncontaminated source flow

samples. This represents the rate of false positives (indication of contamination when none actually exists) when relying

on turbidity alone. Noticeable odor was indicated in 67% of flow samples from contaminated sources, but in none of the

flow samples from uncontaminated sources. This translates to 37% false negatives, but no false positives. Obvious odors

identified included gasoline, oil, sewage, industrial chemicals or detergents, decomposing organic wastes, etc.

100
False negatives are more of a concern than a reasonable number of false positives when working with a screening

methodology. Screening methodologies are used to direct further, more detailed investigations. False positives would be

discarded after further investigation. However, a false negative during a screening investigation results in the dismissal

of a problem outfall for at least the near future. Missed contributors to stream contamination may result in unsatisfactory

in-stream results following the application of costly corrective measures elsewhere.

The method of using physical characteristics to indicate contamination in outfall flows does not allow quantifiable

estimates of the flow components and, if used alone, will likely result in many incorrect determinations, especially false

negatives. These simple characteristics are most useful for identifying gross contamination: only the most significantly

contaminated outfalls and drainage areas would therefore be recognized using this method.

Detergents as lndicafors of Contamination. Results from the Mann-Whitney U tests (Lalor 1994) indicated that

samples from any of the dry-weather flow sources could be correctly classified as clean or contaminated based only on

the measured value of any one of the following parameters: detergents, color, or conductivity. Color and high conductivity

were present in samples from clean sources as well as contaminated sources, but their levels of occurrence were

significantly different between the two groups. If samples from only one source were expected to make up outfall flows,

the level of color or conductivity could be used to distinguish contaminated outfalls from clean outfalls. However, since

multi-source flows occur, measured levels of color or conductivity could fall within acceptable levels because of dilution,

even though a contaminating source was contributing to the flow. Detergents, on the other hand, can be used to

distinguish between clean and contaminated outfalls simply by their presence or absence, using a detection limit of 0.06

mg/L. All samples analyzed from contaminated sources contained detergents in excess of this amount (with the exception

of three septage samples collected from homes discharging only toilet flushing water). No clean source samples were

found to contain detergents. Contaminated sources would be detected in mixtures with uncontaminated waters if they

made up at least 10% of the mixture.

Flow Chart for Most Significant Flow Component Idenfificafion. A further refinement is the flow chart shown on Figure

1. This flow chart describes an analysis strategy which may be used to identify the major component of dry-weather flow

samples in residential and commercial areas. This method does not attempt to distinguish among all potential sources

of dry-weather flows identified earlier, but rather the following four major groups of flow are identified: (1) tap waters

(including domestic tap water, irrigation water and rinse water), (2) natural waters (spring water and shallow ground

water), (3) sanitary wastewaters (sanitary sewage and septic tank discharge), and (4) wash waters (commercial laundry

waters, commercial car wash waters, radiator flushing wastes, and plating bath wastewaters). The use of this method

would not only allow outfall flows to be categorized as contaminated or uncontaminated, but would allow outfalls carrying

sanitary wastewaters to be identified. These outfalls could then receive highest priority for further investigation leading

to source control. This flow chart was designed for use in residential and/or commercial areas only.

In residential and/or commercial areas, all outfalls should be located and examined. The first indicator is the presence

or absence of dry-weather flow. If no dry-weather flow exists at an outfall, then indications of intermittent flows must be

investigated, Specifically, stains, deposits, odors, unusual stream-side vegetation conditions, and damage to outfall

structures can all indicate intermittent non-stormwater flows. However, frequent visits to outfalls over long time periods,

or the use of other monitoring techniques, may be needed to confirm that only stormwater flows occur. If intermittent flow

is not indicated, then the outfall probably does not have a contaminated non-stormwater source. The other points on the

flow chart serve to indicate if a major contaminating source is present, or if the water is uncontaminated. Component

contributions cannot be quantified using this method, and only the “most contaminated” type of source present will be

identified.

If dry-weather flow exists at an outfall, the flow should be sampled and tested for detergents. If detergents are not

present, the flow is probably from a non-contaminated non-stormwater source. The lower limit of detection for detergent

should be about 0.06 mg/L.

101
Industrial or

Industrial/

Commercial

Use

IndustrlaU

Commerclrl

Chackllat

f

I Recheck

Later I I

No A

Not a

Contamlnated

Non-Stormwatrr

Source

Wastewater or

Flow Chart Methodology for ldrntifylng

Most Slgnlflcant Flow Component (Lalor 1994).

Figure 1. Simple Flow Chart Method to Iderkify Significant Contaminating Sources

102
If detergents are not present, fluoride levels can be used to distinguish between flows with treated watersources and

flows with natural sources in communities where water supplies are fluoridated and natural fluoride levels are low. In the

absence of detergents, high fluoride levels would indicate a potable water line leak, irrigation water, or wash/rinse water.

Low fluoride levels would indicate waters originating from springs or shallow groundwater. Based on the flow source

samples tested in this research (Table l), fluoride levels above 0.13 mg/L would most likely indicate that a tap water

source was contributing to the dry-weather flow in the Birmingham, Alabama, study area.

If detergents are present, the flow is probably from a contaminated non-stormwater source, as indicated on Table

1. The ratio of ammonia to potassium can be used to indicate whether or not the source is sanitary wastewater.

Ammonia/potassium ratios greater than 0.60 would indicate likelysanitarywastewater contamination. Ammonia/potassium

ratios were above 0.9 for all septage and sewage samples collected in Birmingham (values ranged from 0.97 to 15.37,

averaging 2.55). Ammonia/potassium ratios for all othersamplescontaining detergents were below 0.7, ranging from 0.00

to 0.65, averaging 0.11. One radiator waste sample had an ammonia/potassium ratio of 0.65.

Non-contaminated samples collected in Birmingham had ammonia/potassium ratios ranging from 0.00 to 0.41, with

a mean value of 0.06 and a median value of 0.03. Using the mean values for non-contaminated samples (0.06) and

sanitary wastewaters (2.55), flows comprised of mixtures containing at least 25% sanitary wastes with the remainder of

the flow from uncontaminated sources would likely be identified as sanitary wastewaters using this method. Flows

containing smaller percent contributions from sanitary wastewaters might be identified as having a wash water source,

but would not be identified as uncontaminated.

Emerging Tools for Identifying Sources of Discharges

Coprostanol and Other Fecal Sterol Compounds Utilized as Tracers of Contamination by Sanitary Sewage. A more

likely indicator of human wastes than fecal coliforms and other “indicator” bacteria may be the use of certain molecular

markers, specifically the fecal sterols, such as coprostanol and epicoprostanol (Eaganhouse, eta/. 1988). However, these

compounds are also discharged by other carnivores in a drainage (especially dogs). A number of research projects have

used these compounds to investigate the presence of sanitary sewage contamination. The most successful application

may be associated with sediment analyses instead of water analyses. As an example, water analyses of coprostanol are

difficult due to the typically very low concentrations found, although the concentrations in many sediments are quite high

and much easier to quantify. Unfortunately, the long persistence of these compounds in the environment easily confuses

recent contamination with historical or intermittent contamination.

Particulates and sediments collected from coastal areas in Spain and Cuba receiving municipal sewage loads were

analyzed by Grimalt, et a/. (1990) to determine the utility of coprostanol as a chemical marker of sewage contamination.

Coprostanol can not by itself be attributed to fecal matter inputs. However, relative contributions of steroid components

can be a useful indicator. When the relative concentrations of coprostanol and coprostanone are higher than their 5?

epimers, or more realistically, other sterol components of background or natural occurrence, it can provide useful

information.

Sediment cores from Santa Monica Basin, CA, and effluent from two local municipal wastewater discharges were

analyzed by Venkatesan and Kaplan (1990) for coprostanol to determine the degree of sewage addition to sediment.

Coprostanols were distributed throughout the basin sediments in association with fine particles. Some stations contained

elevated levels, either due to their proximity to outfalls or because of preferential advection of fine-grained sediments. A

noted decline of coprostanols relative to total sterols from outfalls seaward indicated dilution of sewage by biogenic

sterols.

Other chemical compounds have been utilized for sewage tracer work. Saturated hydrocarbons with 16-l 8 carbons,

and saturated hydrocarbons with 16-21 carbons, in addition to coprostanol, were chosen as markers for sewage in water,

particulate, and sediment samples near the Cocoa, FL, domestic wastewater treatment plant (Holm and Windsor, 1990).

The concentration of the markers was highest at points close to the outfall pipe and diminished with distance. However

the concentration of Cl 6-C21 compounds was high at a site 800 m from the outfall indicating that these compounds were

103
unsuitable markers for locating areas exposed to the sewage plume. The concentrations for the other markers were very

low at this station.

The range of concentrations of coprostanol found in sediments and mussels of Venice; Italy, were reported by

Sherwin, et al. (1993). Raw sewage is still discharged directly into the Venice lagoon. Coprostanol concentrations were

determined in sediment and mussel samples from the lagoon using gas chromatography/mass spectroscopy. Samples

were collected in interior canals and compared to open-bay concentrations. Sediment concentrations ranged from 0.2-41 .O

pg/g (dry weight). Interior canal sediment samples averaged 16 pg/g compared to 2 ug/g found in open bay sediment

samples. Total coprostanol concentrations in mussels ranged from 80 to 620 rig/g (wet weight). No mussels were found

in the four most polluted interior canal sites.

Nichols, eta/. (1996) also examined coprostanol in stormwater and the sea-surface microlayer to distinguish human

versus nonhuman sources of contamination. Other steroid compounds in sewage effluent were investigated by Routledge,

et al. (1998) and Desbrow, et al. (1998) who both examined estrogenic chemicals. The most common found were 17(3-

Estradiol and estrone which were detected at concentrations in the tens of nanograms per liter range. These were

identified as estrogenic through a toxicity identification and evaluation approach, where sequential separations and

analyses identified the sample fractions causing estrogenic activity using a yeast-based estrogen screen. GC/MS was

then used to identify the specific compounds.

Estimating Potential Sanitary Sewage Discharges into Storm Drainage and Receiving Waters using Detergent Tracer

Compounds. As described above, detergent measurements (using methylene blue active substance, MBAS, test

methods) were the most successful individual tracer to indicate contaminated water in storm sewerage dry-weather flows.

Unfortunately, the MBAS method uses hazardous chloroform for an extraction step. Different detergent components,

especially Iinearalkylbenzene sulphonates (LAS) and linear alkylbenzenes (LAB), have also been tried to indicatesewage

dispersal patterns in receiving waters. Boron, a major historical ingredient of laundry chemicals, can also potentially be

used. Boron has the great advantage of being relatively easy to analyze using portable field test kits, while LAS requires

chromatographic equipment. LAS can be measured using HPLC with fluorescent detection, after solid phase extraction,

to very low levels. Fujita, et a/. (1998) developed an efficient enzyme-linked immunosorbent assay (ELISA) for detecting

LAS at levels from 20 to 500 ug/L.

LAS from synthetic surfactants (Terzic and Ahel 1993) which degrade rapidly, as well as nonionic detergents (Zoller,

et a/. 1991) which do not degrade rapidly, have been utilized as sanitary sewage markers. LAS was quickly dispersed

from wastewater outfalls except in areas where wind was calm. In these areas LAS concentrations increased in

freshwater but were unaffected in saline water. After time, the lower alkyl groups were mostly found, possibly as a result

of degradation or settling of longer alkyl chain compounds with sediments. Chung, et a/. (1995) also describe the

distribution and fate of LAS in an urban stream in Korea. They examined different LAS compounds having carbon ratios

of Cl 2 and Cl 3 compared to Cl 0 and Cl 1, plus ratios of phosphates to MBAS and the internal to external isomer ratio

(l/E) as part of their research. Gonalez-Mazo, eta/. (1998) examined LAS in the Bay of Cadiz off the southwest of Spain.

They found that LAS degrades rapidly (Fujita, et al., 1998, found that complete biodegradation of LAS requires several

days), and is also strongly sorbed to particulates. In areas close to shore and near the untreated wastewater discharges,

there is significant vertical stratification of LAS: the top 3 to 5 mm of water had LAS concentrations about 100 times

greater than found at 0.5 m.

Zeng and Vista (1997) and Zeng, et al. (1997) describe a study off of San Diego where LAB was measured, along

with polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) to indicate the relative pollutant

contributions of wastewater from sanitary sewage, nonpoint sources, and hydrocarbon combustion sources. They

developed and tested several indicator ratios (alkyl homologue distributions and parent compound distributions) and

examined the ratio of various PAHs (such as phenanthrene to anthracene, methylphenanthrene to phenanthrene,

fluoranthene to pyrene, and benzo(a)anthracene to chrysene) as tools for distinguishing these sources. They concluded

that LABS are useful tracers of domestic waste inputs to the environment due to their limited sources. They also describe

the use of the internal to external isomer ratio (l/E) to indicate the amount of biodegradation that may have occurred to

the LABS. They observed concentrations of total LABS in sewage effluent of about 3 pg/L, although previous researchers

have seen concentrations of about 150 ug/L in sewage effluent from the same area.

104
The fluorescent properties of detergents have also been used as a tracer by investigating the fluorescent whitening

agents (FWAs), as described by Poiger, et a/. (1996) and Kramer, et a/. (1996). HPLC with fluorescence detection was

used in these studies to quantify very low concentrations of FWAs. The two most frequently used FWAs in household

detergents (DSBP and DAS 1) were found at 7 to 21 ug/L in primary sewage effluent and at 3 to 9 ug/L in secondary

effluent. Raw sewage contains about 10 to 20 ug/L FWAs. The removal mechanisms in sewage treatment processes is

by adsorption to activated sludge. The type of FWAs varies from laundry applications to textile finishing and paper

production, making it possible to identify sewage sources. The FWAs were found in river water at 0.04 to 0.6 pg/L. The

FWAs are not easily biodegradable but they are readily photodegraded. Photodegradation rates have been reported to

be about 7% for DSBP and 71% for DAS 1 in river water exposed to natural sunlight, after one hour exposure.

Subsequent photodegradation is quite slow.

Other Compounds Found in Sanitary Sewage that may be used for IdentiQing Contamination by Sewage. HallingSorensen, eta/. (1998) detected numerous pharmaceutical substances in sewage effluents and in receiving waters. Their

work addressed human health concerns of these low level compounds that can enter downstream drinking water supplies.

However, the information can also be possibly used to help identify sewage contamination. Most of the research has

focused on clofibric acid, a chemical used in cholesterol lowering drugs. It has been found in concentrations ranging from

10 to 165 rig/L in Berlin drinking water samples. Other drugs commonly found include aspirin, caffeine, and ibuprofen.

Current FDA guidance mandates that the maximum concentration of a substance or its active metabolites at the point

of entry into the aquatic environment be less than 1 ug/L (Hun 1998).

Caffeine has been used as an indicator of sewage contamination by several investigators (Shuman and Strand 1996).

The King County, WA, Water Quality Assessment Project is examining the impacts of CSOs on the Duwamish River and

Elliott Bay. They are using both caffeine (representing dissolved CSO constituents) and coprostanol (representing

particulate bound CSO constituents), in conjunction with heavy metals and conventional analyses, to help determine the

contribution of CSOs to the river. The caffeine is unique to sewage, while coprostanol is from both humans and

carnivorous animals and is therefore also in stormwater. They sampled upstream of all CSOs, but with some stormwater

influences, 100 m upstream of the primary CSO discharge (but downstream of other CSOs), within the primary CSO

discharge line, and 100 m downriver of the CSO discharge location. The relationship between caffeine and coprostanol

was fairly consistent for the four sites (coprostanol was about 0.5 to 1.5 ug/L higher than caffeine). Similar patterns were

found among metals; chromium was always the lowest and zincwas the highest. King Co. is also using clean transported

mussels placed in the Duwamish River to measure the bioconcentration potential of metal and organic toxicants and the

effects of the CSOs on mussel growth rates (after 6 weekexposure periods). Paired reference locations are available near

the areas of deployment, but outside the areas of immediate CSO influence. US Water News (1998) also described a

study in Boston Harbor that found caffeine at levels of about 7 ug/L in the harbor water. The caffeine content of regular

coffee is about 700 mg/L, in contrast.

Kratch (1997) summarized several investigations on cataloging the DNA of E. co/i to identify their source in water.

This rapidly emerging technique seems to have great promise in addressing a number of nonpoint source water pollution

issues. The procedure, developed at the Virginia Polytechnic Institute and State University, has been used in Chesapeake

Bay. In one example, it was possible to identify a large wild animal population as the source of fecal coliform

contamination of a shellfish bed, instead of suspected failing septic tanks. DNA patterns in fecal coliforms vary among

animals and birds, and it is relatively easy to distinguish between human and non-human sources of the bacteria.

However, some wild animals have DNA patterns that are not easily distinguishable. Some researchers question the value

of E. co/i DNA fingerprinting believing that there is little direct relationship between E. co/i and human pathogens.

However, this method should be useful to identify the presence of sewage contamination in stormwater or in a receiving

water.

One application of the technique, as described by Krane, et a/. (1999) of Wright State University, used randomly

amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) generated profiles of naturally occurring crayfish.

They found that changes in the underlying genetic diversity of these populations were significantly correlated with the

extent to which they have been exposed to anthropogenic stressors. They concluded that this rapid and relatively simple

technique can be used to develop a sensitive means of directly assessing the impact of stressors upon ecosystems.

These Wright State University researchers have also used the RAPD-PCR techniques on populations of snails, pill bugs,

105
violets, spiders, earthworms, herring, and some benthic macroinvertebrates, finding relatively few obstacles in its use for

different organisms. As noted above, other researchers have used DNA profiling techniques to identify sources of E. co/i

bacteria found in coastal waterways. It is possible that these techniques can be expanded to enable rapid detection of

many different types of pathogens in receiving waters, and the most likely sources of these pathogens.

Other Tracer Methods for identifying Sources of Water. Stable isotopes had been recommended as an efficient

indicator of illicit connections to storm sewerage. A demonstration was conducted in Detroit as part of the Rouge River

project to identify sources of dry weather flows in storm sewerage (Sangal, et al. 1996). Naturally occurring stable

isotopes of oxygen and hydrogen can be used to identify waters originating from different geographical sources (especially

along a north-south gradient). Ma and Spalding (1996) discuss this approach by using stable isotopes to investigate

recharge of groundwaters by surface waters. During water vapor transport from equatorial source regions to higher

latitudes, depletion of heavy isotopes occurs with rain. Deviation from a standard relationship between deuterium and 180

for a specific area indicates that the water has undergone additional evaporation. The ratio is also affected by seasonal

changes. As discussed by Ma and Spalding (1996), the Platte River water is normally derived in part from snowmelt from

the Rocky Mountains, while the groundwater in parts of Nebraska is mainly contributed from the Gulf air stream. The

origins of these waters are sufficiently different and allow good measurements of the recharge rate of the surface water

to the groundwater. In Detroit, Sangal, et al. (1996) used differences in origin between the domestic water supply, local

surface waters, and the local groundwater to identify potential sanitary sewage contributions to the separate storm

sewerage. Rieley, eta/. (1997) used stable isotopes of carbon in marine organisms to distinguish the primary source of

carbon being consumed (sewage sludge vs. natural carbon sources) in two deep sea sewage sludge disposal areas.

Stable isotope analyses would not be able to distinguish between sanitary sewage, industrial discharges, washwaters,

and domestic water, as they all have the same origin, nor would it be possible to distinguish sewage from local

groundwaters if the domestic water supply was from the same local aquifer. This method works best for situations where

the water supply is from a distant source and where separation of waters into separate flow components is not needed.

It may be an excellent tool to study the effects of deep well injection of stormwater on deep aquifers having distant

recharge sources (such as in the Phoenix area). Few laboratories can analyze for these stable isotopes, requiring shipping

and a long wait for the analytical results. Sangal, eta/. (1995) used Geochron Laboratories, in Cambridge, Massachusetts.

Dating of sediments using 137Cs was described by Davis, et al. (1997). Arsenic contaminated sediments in the

Hylebos Waterway in Tacoma, WA, could have originated from numerous sources, including a pesticide manufacturing

facility, a rock-wool plant, steel slags, powdered metal plant, shipbuilding facilities, marinas and arsenic boat paints, and

the Tacoma Smelter. Dating the sediments, combined with knowing the history of potential discharges and conducting

optical and electron microscopic studies of the sediments, was found to be a powerful tool to differentiate between the

different metal sources to the sediments.

Conclusions

Recent tests examined several potential tracer parameters during a project characterizing stormwater that had

collected in telecommunication manholes, funded by Tecordia (previously Bellcore), AT&T, and eight regional telephone

companies throughout the country (Pitt and Clark 1999). Numerous conventional constituents, plus major ions, and

toxicants were measured, along with candidate tracers to indicate sewage contamination of this water. Boron, caffeine,

coprostanol, E. co//, enterococci, fluorescence (using specific wavelengths for detergents), and a simpler test for

detergents were evaluated, along with the use of fluoride, ammonia, potassium, and obvious odors and color. About 700

water samples were evaluated for all of these parameters, with the exception of bacteria and boron (about 250 samples),

and only infrequent samples were analyzed for fluorescence. Coprostanol was found in about 25% of the water samples

(and in about 75% of the 350 sediment samples analyzed). Caffeine was found in very few samples, while elevated E.

coliand enterococci (using IDEXX tests) were observed in about 10% of the samples. Strong sewage odors in water and

sediment samples were also detected in about 10% of the samples. Detergents and fluoride (at >0.3 mg/L) were found

in about 40% of the samples and are expected to have been contaminated with industrial activities (lubricants and

cleansers) and not sewerage. Overall, about 10% of the samples were therefore expected to have been contaminated

with sanitary sewage, about the same rate previously estimated for stormwater systems.

106
Additional laboratory tests, funded by the University of New Orleans and the EPA, were conducted using many

sewage and laundry detergent samples and found that the boron test was a poor indicator of sewage, possibly due to

changes in formulations in modern laundry detergents. Other laboratory tests found that fluorescence was an excellent

indicator of sewage, especially when using specialized “detergent whitener” filter sets, but was not very repeatable. We

also examined several UV absorbance wavelengths as sewage indicators and found excellent correlations with 228 nm,

a wavelength having very little background absorbance in local spring waters, but with a strong response factor with

increasing strengths of sewage. We recommend that our originally developed and tested protocol still be used as the most

efficient routine indicator of sewage contamination of stormwater drainage systems, with the possible addition of specific

E. coliand enterococci measurements and UV absorbance at 228 nm. The numerous exotic tests requiring specialized

instrumentation and expertise reviewed in this paper do not appear to warrant their expense and long analytical turnaround times, except in specialized research situations.

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Elimination of Illicit Connections in Coastal New Hampshire Spurs Cooperation

and Controversy

Natalie Landry and Robert Livingston

New Hampshire Department of Environmental Services

Concord, New Hampshire

Introduction

Discharging stormwater runoff into our waterways has long been an accepted practice. In theory, storm drainage

pipes should only discharge during and after storm events unless the source is groundwater or surface water piped

underground. Therefore, the dry weather discharge should be relatively free of contaminants. However, many

communities across the country are finding out this is not always true. Some cities and towns are discovering illegal

connections of residential and commercial sewer lines to storm water collection systems. Illicit connections have been

identified by the New Hampshire Department of Environmental Services (DES) as the point source of high fecal coliform

levels in the New Hampshire coastal basin (Jones, 1995). These illegal connections pose a health riskto those recreating

in the coastal waters and have forced the closure of shellfish growing waters to harvesting.

Goals of the Coastal Investigations Programs

Determining the extent of dry weather contamination in storm drainage systems is the first step an investigator should

take when researching stormwater pollution. Dry weather flows in storm drainage systems are often the result of

groundwater infiltration, but can also result from inappropriate connections from commercial, industrial, or residential

buildings. In 1996, the New Hampshire DES published the Coastal Basin Nonpoint Source Pollution Assessment and

Abatement Plan (NHDES, 1996) that directed coastal investigations of each community’s storm drainage system during

dry weather. This decision to conduct dry weather investigations in the coast was made after 300 illicit connections were

identified in the northern New Hampshire city of Berlin. State environmental officials were convinced that illicit connections

were always present in storm drainage systems that were once considered a pollution threat only during wet weather.

DES initiated a multi-year effort that focused on identifying and abating the sources of the bacterial violations found

in the state’s coastal waters with the goal of opening shellfish growing waters during dry weather (Landry, 1997). About

the same time, the New Hampshire Estuaries Project (NHEP) began a three-year process of developing a comprehensive

management plan aimed at restoring, protecting and enhancing the water quality and living resources of the state’s

estuaries. The major goal of the NHEP was to address the sources of pollution currently impacting the estuaries and

prevent future problems through effective land use planning and shoreline protection of the coastal resources (NHEP,

1996). To accomplish this goal, part of the NHEP strategy was to locate and remediate the sources of the water quality

violations, primarily bacterial violations, found in the estuaries and coastal waters (Landry, 1997). DES and NHEP

combined resources and developed an investigation strategy with the overall goal of improving and protecting estuarine

water quality.

Specific Program Objectives

The main objectives of the investigation strategy were to identify inappropriate connections in the storm drainage

systems of urban, coastal communities and to eliminate the illicit connections through the available means, which include

voluntary compliance and enforcement.

A Brief Look at Coastal New Hampshire

The eighteen miles of New Hampshire coastline do not begin to tell the story of the state’s abundant marine

resources. The relatively modest coastline is only a small part of the coastal basin. The estuarine resources include the

Great Bay Estuary and seven associated tidal rivers, Hampton Harbor, and Rye Harbor. These waters are used by

residents and many visitors for swimming, boat touring, shellfish harvesting, surfing, and angling. Forty-two communities

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comprise the coastal basin watershed, with a population density just under 300 residents/mile2(Jones, In Review). The

upper watershed is generally undeveloped and forested while the more urban centers are situated in the lower watershed

as the rivers approach the coast.

Ten wastewater treatment facilities are situated on the tributaries of Great Bay and Hampton Harbor and two facilities

discharge directly into the Atlantic Ocean. Coastal communities are working diligently to upgrade the wastewater

treatment facilities and sewage collection systems. Inflow/infiltration problems and undersized pump stations plague the

treatment facilities and have resulted in financial hardshipsforaffected municipalities. Shellfish growing waters have been

temporarily closed after heavy rainstorms when bacteria levels rise due to sewage by-passes. Sewage is a wellrecognized threat to the marine environment because it often contains harmful chemicals, disease-causing bacteria and

viruses, dissolved material and solid matter. Pathogens can cause avariety of illnesses and humans are exposed to these

organisms through contaminated water, shellfish, and fish (Sea Grant, 1999).

Investigating Illicit Connections

This

Recently, more and more watershed studies are investigating inappropriate discharges in storm drainage systems.

pollution source originates from an identifiable point and flows through the storm drainage system to the outfall pipe.

For example, instead of connecting to the sewer system, a direct connection of sewer service discharges into the storm

drainage system. Other inappropriate sources include floor drains and laundry pipes. These inappropriate connections

are also referred to as illicit or illegal cross connections. The health threat and the potential to interfere with stormwater

contamination assessments elevate illicit connections to priority status for watershed managers to investigate.

Pitt et al. (1993) in cooperation with the Center of Environmental Research Information, U.S. Environmental

Protection Agency, published a user’s guide for conducting investigations of illicit connections. Several of the methods

suggested in this guide were implemented during the New Hampshire coastal investigations. Detailed surveys to

determine the extent of contamination through specific water quality monitoring and careful observation of storm drainage

outfalls are recommended for each type of land use in the watershed. Pitt recommends an initial phase of investigative

protocol that includes the initial mapping and field surveys. The initial activities are followed by more detailed watershed

surveys to locate and correct the sources of the contamination in the identified problem areas. After corrective action has

been taken, repeated outfall field surveys are required to ensure that the outfalls remain uncontaminated.

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Surveys of Storm Drainage Systems

Over the course of the investigations, several methods were used, ranging from the initial screening process of

surveying storm drainage discharges to dye testing the indoor plumbing of suspected sources. Steps between the initial

survey and the final determination of the source, included analyzing the discharge for water quality; visual and odor

observations at outfalls, manholes, and catchbasins; smoke testing; and video inspection of the storm drainage and sewer

systems.

Tidal rivers and coastal waters were divided into study sections by community. The urban, downtown centers of these

communities were targeted based on the existence of the storm drainage infrastructure. The investigators compiled maps

and as-built drawings of the storm drainage and sewer infrastructure. If the maps were inaccurate, insufficient, or

unavailable, information on the storm drainage system was developed based on field investigations by the staff, typically

with the assistance of public works employees.

Communities with maps based in a geographic information system (GIS) saved staff time and were generally more

accurate than record drawings that are not updated regularly (Landry, 1997). Tuomari (1996) applied the Rouge

Watershed Geographic Information System to the Wayne County Illicit Connections Detection Program and concluded

that the new GIS strategy eliminated the need to use maps and graphics from disparate reports and sources, significantly

reducing the time and effort once spent on research, field data acquisition, and interpretation.

Beginning in the summer of 1996, the coastal shorelines were surveyed at low tide, on foot or by canoe, depending

on access, for potential pollution sources. All pipes, seeps, streams, and swales with flow were sampled for bacteria. In

addition, temperature was measured and observations relating to the condition of the pipe (stained or structurally

damaged), odor, evidence of untreated wastewater (toilet paper, etc.), turbidity, color, debris, estimated flow, and any

other observations were noted. Dry pipes were rechecked on several occasions for intermittent flow. Evidence indicating

the presence of wastewater and/or elevated bacteria levels prompted further investigation of these locations.

Upstream catchbasins and manholes associated with the outfall pipes that were identified in the screening process

previously described, were surveyed for evidence of wastewater and sampled for bacteria. Smoke testing (using non-toxic

smoke blown into catch basins) was then used to identify buildings connected to the storm drainage system by canvassing

the neighborhood for vents emitting smoke. Final confirmation of an illicit connection from the buildings that emitted smoke

was accomplished with dye testing of indoor plumbing and observing the storm drainage and sewer systems for the

presence/absence of the dye.

Feeder streams were surveyed for outfall pipes with dry weather flow. Other potential bacteriological sources (e.g.,

pigeon roosting sites on bridges) were bracketed with water quality sampling stations. Where contaminated seeps and

swales were suspected, the drainage area was surveyed for potential sources such as broken sewer mains.

Water Quality Results

Bacteria data (1997/98) from outfall pipes with confirmed cross connections ranged from 1,700 - >l ,OOO,OOO f. co/i

counts/l 00 ml during dry weather in Dover, New Hampshire. Many outfall pipes with cross connections had a gray biomat

comprised of filamentous bacteria coating the inside of the pipe and, often, the rocks or sediment below. These biomats

were used as a wastewater indicator based on the presence of these mats at more than 50% of the outfalls with confirmed

cross connections.

Dr. Stephen Jones of the University of New Hampshire Jackson Estuarine Laboratory conducted a twelve-month

study that examined the significance of all flow coming from urban storm drainage systems in the downtown Dover

watershed of the Cocheco River (Jones, 1998). Jones found that storm drains were consistent sources of relatively high

concentrations of bacterial indicators and pathogens at concentrations that exceeded state standards for recreational and

shellfish-growing waters during both dry and wet weather.

Flow from a damaged stormwater outfall pipe was determined to have a geometric mean E. co/i concentration of

1,047,199 cfu/lOO ml and a dissolved inorganic nitrogen (DIN) concentration of 22.4 mg/l. The data were brought to the

attention of DES and an investigation revealed a cross connection from a commercial building. Dr. Jones continued to

monitor the quality of flow after the cross connection was eliminated and the results show a significant decline in both

bacteria and DIN geometric means. The post-repair results were 93 E. co/i cfu/lOO ml and 7.2 DIN mg/l.

112
Although no public health problems were known to have occurred as a result of exposure to bacterial pathogens in

the Cocheco River, the contamination may be a significant contribution to the fecal-borne bacteria that are presently the

reason for closing the area’s shellfish growing waters in New Hampshire and restricting harvests in Maine (Jones, 1998).

Remedial Actions

Once confirmed, illicit connections in coastal New Hampshire have been eliminated in different ways. The most

desired course of action from the regulatory perspective is voluntary compliance and many fixes have been accomplished

through this process. Economics and prioritization of the many demands on public works departments sometimes compel

the state and federal environmental agencies to initiate regulatory action to eliminate raw wastewater discharges into

surface waters. Lawsuits, although not common, have been filed against municipalities after cross connections were

discovered.

Voluntary Compliance: Town of Exeter Case Study

In 1994, researchers at the UNH Jackson Estuarine Laboratory (Jones and Langan, 1995) reported elevated dryweather bacterial levels collected in Norris Brook, a tributary to the Squamscott River in Exeter, New Hampshire. In 1996,

DES collected bacteria samples at various locations on Norris Brook (NHDES, 1997) and found relatively low E. co/i

concentrations of ~150 counts/l00 ml. In 1998, an Exeter official urged DES to investigate the watershed for

contamination based on the 1994 data that showed a fecal coliform concentration of 600 counts/l 00 ml. In April of 1998,

DES and a town official conducted a survey of the lower watershed and discovered a storm drainage outfall discharging

a large volume of flow even though the weather had been dry. Upon closer inspection, toilet paper was observed in the

outfall pipe and the immediate area.

The town public works department was notified of the survey results and, following reminders by DES, began

investigations to determine the sources of untreated wastewater. Progress was slowed because several of the residences

were rental properties which involved contacting the owner, who was in some cases from out-of-state, and gaining

permission to access the building for dye testing. By November, the town reported that a few of the cross connections

still remained. DES considered enforcement action and an administrative fine but did not take that action to maintain the

spirit of cooperation. In January of 1999, the town reported that the owner of the last remaining property to be dye tested

was not responding to requests for access. More prodding by DES followed and in February 1999, DES received

notification that the cross connections were eliminated. A follow up inspection confirmed the absence of untreated

wastewater in the storm drainage outfall.

A lesson learned from this experience is that a persistent, local advocate is often the key to maintaining attention on

a local water quality problem. In addition, local advocates, whether a conservation commissioner, selectmen, or citizen,

often have detailed knowledge of the complaint and the locale, which provides valuable and time-saving information to

the state investigators.

Time and resource demands on local officials as well as state investigators can cause this process to be distressingly

slow. Budgeting for 2-3 cross connection investigations and fixes per year is recommended at approximately $6,000 per

fix, to help alleviate the unexpected financial burdens on urban communities when illicit connections are found.

Bacteria alone should not be the determining factor of the presence or absence of an illicit connection for a variety

of reasons. Chlorine or other toxins in untreated wastewater may depress bacteria levels and bacteria lack conservative

behavior, which deem it a poor indicator (Pitt, 1993). Investigators have found that a careful and thorough outfall survey

is usually more informative than just collecting water samples.

Enforcement Action: City of Newmarket Case Study

Enforcement is another tool available to DES to achieve compliance. For example, setting timetables for compliance

milestones in a legal document is a method that, while typically thought of as a burden to a community, may actually

provide the impetus for action in a positive way. Public works departments of New Hampshire coastal communities are

not equipped with large, discretionary budgets to address unplanned remediation of illicit connections. When faced with

this dilemma, an enforcement action against the community provides public works departments with the validation to

support a request for additional funding from the officials who approve the allocation of funds.

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As the mill Town of Newmarket, New Hampshire, developed over the years, a small watercourse named Moonlight

Brook was built over and culverted in the center of downtown. In 1996, DES investigated Moonlight Brook based on

historic elevated bacteria levels. The DES investigation revealed dry weather E. coliconcentrations as high as 41,600

counts/l OOml in the brook. DES encouraged the town to initiate dye testing of the structures in the vicinity of Moonlight

Brook but, at that time, the town was reluctant to allocate staff and funding for clean up efforts (NHDES, 1997).

An administrative order was issued by the US Environmental Protection Agency for various violations of permitted

effluent limitations in October, 1997 and included a requirement that the town eliminate the raw sewage discharges from

the storm sewer system (USEPA Docket No. 97-78). The order required a plan and schedule for eliminating any pollutants

discharging during dry weather. The order also specified sampling of each active dry weather discharge that remained

following elimination of the illicit connections to the system identified by the town’s fieldwork.

In response to the order, the town hired an environmental consultant to address the problems at the wastewater

treatment facility and the illicit connections. During the summer of 1997, the consultant and the town performed a dye

study of the subdrainage area that the town suspected was the likely source of bacterial contamination identified at the

discharge. The dye study resulted in the identification of a total of four untreated discharges to the storm drainage system

from three properties. A subsequent video inspection of the sewer lines adjacent to these properties revealed that the

sewer service connections from these properties might have been installed at the time the original sewer was constructed.

The consultant then concluded that this would indicate the sources of sewage discharging to the storm drainage are

broken sewer service connections rather than direct connections. The town stated that the remedial work would be

completed by June 1998 (Plante, 1998).

Another storm discharge pipe servicing this area was separated in 1985 and 1986, at which time dye testing was

performed to identify sanitary services that were connected to the sewer. The consultant determined that it would be

unlikely that direct sanitary service connections to the storm drain were present in this area, however, broken service

connections could result in sewage entering the storm drain culvert along Main Street. A dye study was planned for May

1998.

A total of 59 properties were included in the dye-testing program. Four of the properties were confirmed to be crossconnected to the storm drainage system. Two of the four were the result of direct connections of sewer laterals to the

drainage system. The remaining two were a result of exfiltration from the sewer lateral through the ground to the drain

line (Town of Newmarket, 1999). The town reports a 90% reduction in the E. colicounts following the elimination of the

illicit discharges.

Legal Action: City of Dover Case Study

In the 1970’s, the City of Dover, New Hampshire, constructed a new sewage collection system and treatment facility.

In 1997, DES investigators began surveying the storm drainage outfalls for contamination. Around this same time,

University of New Hampshire researcher Dr. Stephen Jones initiated a study in Dover to determine the significance of

flow (both dry and wet weather) coming from urban storm drainage systems (Jones, 1998). Jones identified a source of

bacterial contamination to be a cross connection later confirmed by DES and the City of Dover Public Works Department.

The city fixed the illicit connection by connecting the sanitary service into the sewer main, at no charge to the building

owner, while noting substantial flow from this service due to a hair salon in the building.

After learning about the existence of the cross connection, the building owners made an unsuccessful request to the

city for an abatement of the sewer fees they had paid since 1981 and initiated legal proceedings. The city alleged that

the case law mandated a decision in its favor and filed a motion for summary judgement (Strafford Superior Court, Order

#98-C-207). In a responding order from the judge, the case law was said to illustrate that the Court had considered a

variety of factors in related cases including (1) whether the new and old system were integral to one another, (2) whether

the benefit provided to the plaintiff under the new and old systems was comparable, and (3) whether the property owner

had access to the new system. The motion for summary judgment was denied because the Court found that these were

issues for a jury and that summary judgment at that stage would be premature.

A trial date was set. One week before the trial was to occur, the two parties settled out of court. The terms of the

settlement were confidential. If the property owners were successful in seeking a tax abatement and damages for unjust

enrichment, implied contract, and negligent misrepresentation, as sought, the pollution investigations could have been

114
in jeopardy of becoming ineffective. Such a precedent could have led to other similar suits and would effectively remove

the incentive for municipalities to be proactive in fixing cross connections.

Conclusions

The Department of Environmental Services, in conjunction with the New Hampshire Estuaries Project, has

systematically identified illicit connections in the urban communities of coastal New Hampshire. Applying both voluntary

compliance and enforcement has resulted in the removal of cross connections to the storm drainage systems and a

decrease in the contamination reaching the coastal surface waters. DES is currently monitoring the shellfish growing

waters to determine the extent of water quality improvement resulting from the removal of illicit connections.

References

Hamilton R. Krans, and Allan B. Krans v. City of Dover, No. 98-C-207 (Strafford, SS. N.H. Dec. 28,1998) (order denying

defendant’s motion for summary judgment.)

Jones, S.H. and R. Langan. 1995. Assessment of Nonpoint Source Pollution in Tributaries to the Great Bay Estuary. Final

Report. New Hampshire Office of State Planning/Coastal Program. Concord, New Hampshire.

Jones, Stephen, Ph.D. In Review. A Technical Characterization of Estuarine and Coastal New Hampshire. New

Hampshire Estuaries Project, Office of State Planning, Portsmouth, New Hampshire.

Jones, Stephen, Ph.D. 1998. Stormwater contamination of New Hampshire Coastal Surface Waters. Final Report

Submitted to the New Hampshire Coastal Program/Office of State Planning, Concord, New Hampshire.

Jones, Stephen, Ph.D. 1999. Public Health Significance of Stormwater-Borne Microorganisms. Final Report to the New

Hampshire Department of Environmental Services, Concord, New Hampshire.

Landry, Natalie. 1997. An Investigations of Water Quality in New Hampshire Estuaries. Final Report to the New

Hampshire Estuaries Project. New Hampshire Department of Environmental Services, Concord, New Hampshire.

New Hampshire Department of Environmental Services (NHDES). 1996.1996 Coastal Basin Nonpoint Source Pollution

Assessment and Abatement Plan. Concord, New Hampshire.

New Hampshire Department of Environmental Services (NHDES). 1997. 1996 Nonpoint Source Coastal Assessment

Report. Concord, New Hampshire.

New Hampshire Estuaries Project (NHEP). 1996. New Hampshire Estuaries Project National Estuary Program: EPA/State

Management Conference Agreement. New Hampshire Office of State Planning, Concord, New Hampshire.

Pitt, Robert, Melinda Lalor, Richard Field, Donald Dean Adrian, and Donald Barbe. 1993. Investigation of Inappropriate

Pollutant Entries into Storm Drainage Systems, A Users Guide. United States Environmental Protection Agency.

EPA/600/r-921238.

Plante, Thomas R., P.E. 1998. Report to the US Environmental Protection Agency Regarding Administrative Order No.

97-87, Item 6-Dry Weather Discharges From Stormwater System. New Hampshire Department of Environmental

Services, National Point Discharge Elimination System files, Concord, New Hampshire.

Sea Grant. 1999. Sewage: Wastewater Major Pollutant Challenge. Sea Grant National Media Relations Office, National

Sea Grant College Program. http://www.seagrantnews.org/news/sewage.html.

Town of Newmarket. 1999. Storm Drain/Sewer Cross Connections, Identification and Correction. Final report to the New

Hampshire Estuaries Project. Prepared by Underwood Engineers, Portsmouth, New Hampshire.

Tuomari, Dean. 1996. Rouge River Watershed Illicit Sewer Connection Detection Program: A GIS Application. Watershed

96. Wayne County Department of Environment, Detroit, Michigan.

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United States Environmental Protection Agency. 1997. Administrative Order No. 97-78, Findings of Violation and Order

for Compliance In the Matter of Newmarket, New Hampshire, NPDES Permit No. NH01 00196.

116
Using Collaborative Problem-Solving to Protect North Carolina’s Coastal

Resources: The Experience of the White Oak River Advisory Board*

Leon E. Danielson, C. Suzanne Hoover, Christy A. Perrin

North Carolina State University

Department of Agricultural and Resource Economics

Raleigh, NC

Nancy M. White

North Carolina State University

School of Design

Raleigh, NC

Ron Elmore

North Carolina Department of Transportation

Raleigh, NC

Jennifer L. Platt

Town of Cary

Cary, NC

Introduction

In North Carolina coastal estuarine systems, land use change has been implicated as a significant cause of water

quality impairment (NC Department of Environment and Natural Resources, 1997; White, et al., 1998). Such development

processes change surface hydrology, pollutant delivery, and, as a consequence, adjacent water quality. Decisions

regarding placement, density, and type of development are controlled by policy implementation at the local level.

Furthermore, while the degree of impact may vary with each location, it is the cumulative effects throughout a watershed

that can be most damaging to water quality. Hence, there is a need to develop and enact policy locally, but on a multijurisdictional, watershed basis.

Increasingly, local communities and governments are showing interest in playing a role in developing and

implementing solutions to water quality problems (NC Department of Environment and Natural Resources, 1997).

However, logistical complications arise upon implementation of this concept. First, a mechanism for effectively involving

local citizen stakeholders in the policymaking process may not exist and/or is difficult to establish (Danielson, 1998).

Second, technical data needed to address local issues and concerns are often not readily available, or are in a form not

easily understood. Third, programs for addressing water quality problems on a watershed-basis may not exist, suggesting

a need to develop, coordinate, and deliver multi-jurisdictional education on water quality issues and policy alternatives.

Through a project entitled Watershed Education for Communities and Local Officials (W/X0), the North Carolina

Cooperative Extension Service has worked with a number of state and federal agencies, along with citizens and local

governments within a coastal watershed to address these needs.

The goal of this project is to improve water quality in all of the White Oak River Watershed through involvement and

education of citizens and government officials who live and work in the watershed. The project’s main thrusts are : 1) the

delivery of technical information and educational material on water quality, management strategies, and policy options

that support watershed-based planning; 2) the empowerment of local citizens by facilitating collaborative partnerships

between communities, local officials, and state agencies within the watershed; and 3) the facilitation of the development

* Funding for this project is provided by USDA-CSREES under project number 97.EWQI-l-0150.

117
of local stakeholder - driven policy recommendations for the entire watershed. This paper discusses the application of

these concepts to an issue of critical importance to local citizens.

Background

The White Oak River watershed is one of four rivers in the White Oak River Basin (Figure 1). It is 48 miles long and

encompasses 320 mi2 . The watershed begins in freshwater creeks and swamps of Jones County, NC, and contains

portions of three other counties--Craven, Onslow, and Carteret. Along its route to Bogue Sound and the Atlantic Ocean,

the river traverses between 30 ft. banks, which are relics of ancient dune ridges. This river is home to five threatened

or endangered organisms, including alligators; loggerhead, green, and leatherback turtles, and the Croatan crayfish. The

river and its estuarine waters have extensive primary nursery waters and provide habitat for several anadromous speciesherring, shad, striped bass, and sturgeon. The majority of the river is classified as SA, or saltwater suitable for

commercial shellfish harvesting.

White Oak River Watershed

Nurth Curolinu

4

Onslow Countv

Sub-Watersheds ,”

raven County

Figure 1. General map of White Oak River Watershed in North Carolina.

The White Oak River watershed has six major land cover/land use classes with wetlands encompassing the largest

single type at 52% of the total. Forests are the second largest land cover type constituting the majority of the headwaters

in the Croatan National and Hoffman State Forests (22%). A very small portion of the watershed is urban (2%) and

agricultural (11%) (NC Department of Environment and Natural Resources, 1997).

Despite the low level of urbanization, the North Carolina Division of Water Quality’s basinwide management plan notes

an increase in shellfish closures in the river (North Carolina Division of Environmental and Natural Resources, 1997). At

state-sponsored public meetings, over 100 citizens expressed concern and called for more public education on water

quality.

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Recognizing the interest of their constituencies in water quality education, local NC Cooperative Extension Service

leaders assembled a project team involving members from the North Carolina Division of Water Quality, North Carolina

Division of Coastal Management, North Carolina Division of Environmental Health - Shellfish Sanitation Branch, North

Carolina Cooperative Extension, and 25 citizens who comprise the stakeholder-based Advisory Board for the White Oak

River Watershed. This group includes crop farmers, livestock farmers, fisherpersons, developers, foresters, tourism

directors, teachers, scientists, and local government officials from the watershed (see Table 1). The citizen advisory

board is the decision-making entity. The government agency representatives and Cooperative Extension personnel

function as support staff to the Board. Support staff provide resources, perform research and reviews, make reports,

serve as technical advisors, and provide formal facilitation and consensus-building services.

The White Oak Advisory Board’s Primary Issue of Concern

The Board began meeting in August of 1996. Their first task was to prioritize water quality issues upon which to focus

their efforts, Board members expressed concern that past bridge and road construction across the mouth of the river had

contributed to a decline in water quality. Furthermore, this road, Highway 24, was slated for expansion, and they were

concerned that this would exacerbate the problems. The Board acknowledged the need for expansion of the road, but

recognized a unique opportunity to mitigate its impact if they could move quickly to work with the North Carolina

Department of Transportation (NC-DOT)

At the time that the Board was convened and identified the highway and its expansion as an issue, NC-DOT was in

the process of conducting an Environmental Assessment of the project and were anticipating a Finding of No Significant

Impact. During a meeting between the Extension Project Team and NC-DOT, DOT representatives were made aware

of the Board’s concerns and expressed an interest in working with the Board to address those concerns. However, timing

was an issue because in several months, NC-DOT was planning right of way acquisition to begin the expansion project.

Because of the urgency of the matter, the Board resolved to meet twice monthly and work to develop their comments and

recommendations.

Technical Information Gathered by the Board

In response to the Board’s inquiry, the Project Team reviewed, summarized, and presented scientificstudies that had

been conducted on the river that related to sedimentation and flow patterns in the river and the possible effects of highway

construction over the mouth of the river. Results from the following four studies were especially useful in understanding

the science behind this policy issue.

Table 1. White Oak River Watershed Advisory Board - Stakeholder Composition.
One study (Martens and Goldhaber, 1978) determined that the metabolic pathways by which bacteria degrades

organic matter in the sediments differ depending on whether the overlying aquatic environment is salty or fresh.

Chemistry analyses done on soil cores taken at various locations in the river found framboidal pyrite at upstream samples,

which indicated that saltwater wedges had previously penetrated further upstream than current patterns in soil chemistry

showed. These results provided evidence to the Board that saltwater flows in the river had changed over time.

Adams, Benniger, Hosier, Overton, and Reed (1982) studied water circulation and sedimentation patterns in the White

Oak Estuary and found that sedimentation in the estuary varies from 0.3 cm/yr to 5 cmlyr. approximating the annual rate

of submergence along the Atlantic coast. Their study confirmed for the Board that the system is a flood tide dominated

system with sediment transport primarily occurring during storms with strong on-shore winds. The study also noted that

the construction of the lntracoastal Waterway (ICWW) in 1930-32 in conjunction with the construction of Highway 24 in

1933 altered channel flow from one channel (adjacent to Huggins Island) to another (adjacent to the mainland near

Highway 24). Spoil deposition from dredging operations may also be responsible for decreased channel flow in the west

channel of the Inlet. The authors noted no evidence of a declining fishery based on the fact that it was comparable to

other fisheries in the area and in line with historical production rates for the estuary. This study also quantified the extent

of fill and alteration to the estuary caused by the original construction of the ICWW and the road in 1932 and 1933,

respectively. Historical maps, when compared to current data, showed that two inlets were closed and that more than

80% of the river was obstructed by these projects.

Benniger and Martens (1983) investigated the age and the sources of organic matter in the estuary. This study

characterized the organic matter degradation rates, which is important in understanding the estuary’s capability to process

organic inputs. The researchers determined that the upstream organic matter inputs were primarily terrestrial and the

downstream organic inputs were primarily marine. However, they found that microbial processes acted preferentially to

remove recently produced organic matter. This implies that recently produced or partially treated organic matter could

substantially increase sediment oxygen demand and the rate of nutrient regeneration. This would increase the

vulnerability of the estuaries to anoxia and algal blooms.

Kelley, Martens, and Chanton (1990) by collecting and analyzing sediment cores, characterized the relative

remineralization rates of sedimentary carbon for the fresh and saltwater environments in the river. They found that the

upstream environment, which is dominated by terrestrial inputs and the process of methane reduction, remineralized at

a rate three times faster than the downstream site, which is dominated by marine inputs and uses sulfate reduction as

the energy pathway for organic matter remineralization. As indicated in the previously described paper by Martens and

Goldhaber (1978), saltwater circulation patterns, as well as freshwater inputs, appear to have changed such that the

estuarine ecology has shifted towards a more freshwater system. Since freshwater facilitates rapid remineralization of

organic carbons, this, over time, can reduce the river’s buffering capacity and result in nutrient enrichment.

Initial Conclusions of Board

Based on these and other related studies, the Board concluded the following:

. Salt wedges that used to extend upstream have not occurred in recent history.

. Organic inputs upstream are from terrestrial sources and downstream are from marine sources.

. Salinity regimes in the river are highly variable seasonally and spatially.

. Salinity helps buffer the river from nutrient inputs.

. Sedimentation at the mouth of the estuary was considered normal for coastal estuary systems.

. There was no evidence to support a perceived decline in the fishery.

. Increased fresh water inputs from the expanded impervious surface area related to the highway expansion may

have a negative impact.

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. Higher salinity reduces concentrations of fecal coliform bacteria.

. Ditching and other means of moving water faster off the land causes problems with increased freshwater to the river

as well as increased bacterial contamination in shellfish beds.

. There is a significant shellfish resource at the mouth of the river that has historically remained open.

Next, the Advisory Board convened a panel of specialists to discuss this information and potential mitigation

strategies. The panel participants included:

. Dr. Larry K. Benninger, Geologist, University of North Carolina at Chapel Hill (UNC-CH);

. Archie Hankins, Biologist, NC-DOT;

. Tom Jarrett, Hydraulic Modeling, United States Army Corps of Engineers (USCOE);

. Dr. Chris Martens, Marine Sciences, UNC-CH;

. Dr. Paul Hosier, Biologist, UNC-CH;

. Dr. Rick Leuttich, Sedimentary Geologist, UNC-CH; and

. Howard Varnam, Hydrologist, USCOE.

The panel reviewed the scientific information presented to the Board, and they agreed that there has been an impact

on the circulation and flushing of the White Oak River since the construction of the causeway and the ICWW, but

quantification of those effects would require intensive modeling that would take a minimum of 1.5 to 2 years. The panel

felt that any action to increase circulation and salt water inputs to the river would have an overall positive effect on water

quality. However, the best manner in which to accomplish those goals and the particular effects on fisheries,

sedimentation, or other water resource values would be difficult without modeling studies. The panel concluded that due

to changes in land use, hydrology in the watershed had been altered. As a result, runoff volume during storm flows has

increased. This increases pollutant loading and increases erosion processes during storms. The panel noted that a

reduction in freshwater runoff would not have any significant effect on the diversity and density of species, but on their

distribution. This would have little effect on flora and fauna in the river, but might improve water quality. The panel also

noted that the most effective strategy for protecting water quality is to involve all of the communities impacting the system

and to implement overall land use planning in the watershed. It was suggested that the group needed to define their water

quality goals and how they want to manage the river and watershed to achieve those goals. Individual actions for

localized effects would require some additional modeling and research to determine the best options.

The panel concluded with a list of mitigation recommendations listed below:

. Pursue a study of the river to determine what, if any, actions should be taken to improve circulation up and

downstream of the highway.

. Examine options to manage stormwater in new and existing developments.

. Pursue the maintenance of buffers along creeks and streams.

. Pursue stricter enforcement of sediment and erosion control at construction sites.

. Endorse, encourage, and facilitate the use of BMPs in forests and farms.

. Work to develop a mechanism for watershed - based or coordinated land-use planning to address all of the

suggestions.

. Explore alternative waste management strategies for both single users and municipalities to reduce nutrients.

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Over the next several meetings, and as a consequence of these findings, the Board recommended the following

actions;

1. To reduce freshwater inputs to the estuary and possible negative impacts of highway runoff on water quality, the

Advisory Board recommended storm water runoff from bridge and highway expansion not be discharged into the

river and that the Department of Transportation (DOT) explore options to eliminate discharge into the waterways.

At a minimum, discharge from Highway 24 should be directed south (downstream) of the causeway to prevent

impacts to shellfish. In addition, it was recommended that amelioration of the velocity, volume, and quality of that

runoff be implemented, if feasible.

2. Historic maps showed that, prior to the 1930’s, the mouth of the White Oak River was open and unrestricted,

allowing free tidal flow. In 1932 and 1933, Department of Transportation and US Army Corps of Engineers (ACOE)

projects closed approximately 80% of the mouth of the river and altered physical processes. The Advisory Board

recommended that to restore salinity regimes, increase tidal circulation, and reduce sedimentation, DOT take actions

to reopen the mouth of the river to the maximum extent possible. One option would be the creation of a north-south

channel connecting the estuary with the sound near the current location of the Flying Bridge Restaurant on the

Carteret County side of the river spanned by a bridge or connected by a culvert. Additionally, the Board

recommended that DOT and ACOE access ACOE ecological restoration funds and collaborate with each other to

mitigate the impacts of this expansion and past actions.

3. Since efforts to open the channel would not remain effective unless the State of North Carolina initiates an ongoing

maintenance program, the Advisory Board recommended that a long-term maintenance program supporting

improved circulation, reduced sedimentation, and restored salinity regimes be developed and implemented by

responsible agencies.

These recommendations were presented to and adopted by commissioners for Carteret and Jones Counties in May

and June of 1997. In addition, the White Oak River Watershed Advisory Commission of Onslow County (a group

appointed by the Onslow County Board of Commissioners to address water quality issues in Onslow County) endorsed

the recommendations of the Board at their May of 1997, meeting. This collaborative, consistent, watershed-based policy

statement became part of the public record for the NC-DOT hearings in May of 1997, and a preliminary draft was included

in the NC Division of Water Quality’s Basinwide Water Quality Management Plan for the White Oak River Basin (North

Carolina Division of Environmental and Natural Resources, 1997).

Response to the Recommendations of the Board

At a joint meeting that included representatives of the NC-DOT, the White Oak River Advisory Board, the Extension

Project Team, and USCOE, the DOT agreed to support the Board’s recommendations and revise their stormwater plans

to direct runoff away from the shellfish resource in the river.

Blueprints for construction were redrawn reflecting the following features. In the vicinity of the bridges carrying

Highway 24 over the White Oak River at Swansboro, NC-DOT agreed, to the extent possible, to direct the stormwater

runoff from the roadway to the Bogue Sound side of Highway 24 and away from the river. In Swansboro (west of the

island causeway), the existing stormwater collection system (which has outfalls on both the river and sound side of

Highway 24) will continue to be used for the runoff following roadway expansion, thus preventing the need for additional

outfalls in the river.

From the island causeway eastward for approximately 2.5 miles, the stormwater runoff from the highway will be

collected and piped to outfalls on the sound side of Highway 24. Also, NC-DOT has designed special channelization

islands for commercial driveways to accommodate some of the stormwater runoff from the highway and bridges. These

water quality islands are depressed inside the curb to allow the first inch of highway runoff to pond within these islands

and filter through the grassed areas located there. The filtered runoff from these islands is then collected and piped to

outfalls on the sound side of Highway 24.

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In addition to the stormwater design changes, it was agreed that DOT would cooperate with other state and federal

agencies in any efforts to improve circulation and tidal flushing. Currently, the Board is continuing to work on adding a

section to the Congressional Water Resources Development Actthat would authorize the USCOE to conduct the study

necessary to determine what, if any, actions could be taken to improve flushing in the river.

Conclusions

Local stakeholder-based citizen groups can impact policies that affect their environment. Support for gathering,

summarizing, and delivering technical information to local citizens and governments is an important aspect of the success

of these processes. Knowing who to approach for answers to specific questions, and where to look for scientific

information is an important function of the group’s technical support. In addition, translating the information gathered into

digestible and usable material is also critical.

References

Adams, David A.; Larry K. Benniger; Paul E. Hosier; Margery F. Over-ton; and James P. Reed. 1982. White Oak River

Management Project. Office of Water Resources, NC Dept. of Natural Resources and Community Development, Raleigh,

NC.

Benniger, Larry K. and Christopher S. Martens. 1983. Sources and fates of sedimentary organic matter in the White Oak

and Neuse River estuaries. WRRI Rept. # 194.

Danielson, L. E., 1998. Are We Really Prepared to be Honest Brokers and Conflict Resolvers in Controversial

Situations? Organized Symposia in Dealing with Controversy in Natural Resource Issues, at AAEA Annual Conference,

Aug 4, 1998. Salt Lake City, Utah.

Kelley, Cheryl A.; Christopher S. Martens; and Jeffery P. Chanton. 1990. Variations in the sedimentary carbons

remineralization rates in the White Oak River estuary, North Carolina.

Martens, Christopher S. and Martin B. Goldhaber. 1978. Early diagenesis in transitional sedimentary environments of

the White Oak River Estuary, North Carolina. Limnol. Oceanogr., 23(3), 428-441.

North Carolina Department of Environment and Natural Resources, 1997. White Oak River Basinwide Water Quality

Management Plan. North Carolina Division of Water Quality, Raleigh, North Carolina, 227 pps.

White, N. M., D. E. Line, J.D. Potts, William Kirby-Smith, Barbara Doll and W.F. Hunt. 1999. Jump Run Creek Shellfish

Restoration Project. In review, Journal of Shellfish Research.

123
Community Responses to Stormwater Pollution:

Case Study Findings with Examples from the Midwest

George P. Aponte Clarke, Policy Analyst

Natural Resources Defense Council

New York, NY

Peter H. Lehner’, Chief

Environmental Protection Bureau

New York State Attorney General’s Office

New York, NY

Diane M. Cameron’, President

Cameron Associates

Kensington, MD

Andrew G. Frank3, Litigation Associate

Paul, Weiss, Rifkind, Wharton, and Garrison

New York, NY

Stormwater runoff threatens the nation’s waterways and public health, and costs Americans hundreds of millions of

dollars each year. Concerns about urban runoff and interest in proposed new federal stormwater regulations prompted

the Natural Resources Defense Council (NRDC) to document existing, effective stormwater strategies. Our report aims

to encourage municipal action and empower communities to address this critical issue. More than 150 case studies from

across the nation were compiled and evaluated to highlight effective pollution prevention, administrative, and financing

strategies for addressing stormwater runoff. The case studies show, on a practical level, that stormwater management

can be environmentally effective, economically advantageous, and politicallyfeasible. The reportalsoforms the foundation

of a comprehensive outreach effort. Together, they help guide communities as they implement or improve stormwater

management programs by providing detailed examples of proven tools and approaches used to prevent stormwater

pollution. Collectively, the case studies offer an outline for further successful stormwater management strategies.

Elements critical to the effectiveness of these programs include: a pollution prevention emphasis with structural treatment

measures when needed; a focus on preserving natural features and processes; programs that inform and involve the

public; a framework that creates and maintains accountability; a dedicated and equitable funding source to ensure longterm viability; strong leadership; and effective administration. These broad themes translate into aset of nine local actions

for addressing the technical, social, and political issues associated with stormwater runoff. The case studies show that

following these actions will help communities form a sound stormwater policy.

Key Terms: urban stormwater runoff, impervious surfaces, pollution prevention, best management practices, diffuse

pollution, accountability.

‘formerly Senior Attorney and Clean Water Project Director, Natural Resources Defense Council

2 formerly Senior Scientist, Natural Resources Defense Council

3 formerly Policy Analyst, Natural Resources Defense Council

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Introduction

Currently, there is substantial concern about the impacts of urban and suburban runoff. Pollution from diffuse sources,

including urban stormwater, is the leading source of contamination in the nation’s waters (U.S. Environmental Protection

Agency, 1997a). Stormwater runoff pollution is a particularly important issue since most of the population of the United

States lives in urban and coastal areas. Water resources in urban and coastal areas are highly vulnerable to and are often

severely degraded by stormwater runoff. Specifically, urban and suburban runoff is the second most prevalent source

of water quality impairment in the nation’s estuaries after industrial discharges (U.S. Environmental Protection Agency,

1998b).

Economic impacts are an important aspect of this concern. Even a partial accounting shows that hundreds of millions

of dollars are lost each year through added government expenditures, illness, or loss in economic output due to urban

runoff pollution and damages (U.S. Environmental Protection Agency, 1998a). The ecological damage is also severe and

is at least as significant. In particular, uncontrolled urban runoff contributes to hydrologic and habitat modification, two

important sources of river impairment identified by the U.S. Environmental Protection Agency (EPA).

The polluted stormwater runoff problem has two main components: the increased volume and rate of runoff from

impervious surfaces and the concentration of pollutants in the runoff. Both components are closely related to development

in urban and urbanizing areas (Booth and Reinelt, 1993; Schueler, 1994; U.S. Environmental Protection Agency, 1997b).

When impervious cover (roads, highways, parking lots, and roof tops) reaches between 10 and 20 percent of the area

of a watershed, ecological stress becomes clearly apparent (Klein, 1979; Booth and Reinelt, 1993; Schueler, 1994).

Everyday activities can deposit on these surfaces a coating of various harmful materials. When it rains or when snows

melts, many of these pollutants are washed into receiving waters, often without any treatment.

The deposition of pollutants and the increased velocity and volume of runoff together cause dramatic changes in

hydrology and water quality (Klein, 1979; Jones and Clark, 1987; Booth, 1990; Galli, 1990; U.S. Environmental Protection

Agency, 1997b). These changes affect ecosystem functions, biological diversity, public health, recreation, economic

activity, and general community well-being (Bannerman ef al., 1993; Novotny and Olem, 1994; Haile et al., 1996;

Carpenter et al., 1998). Urban stormwater is not alone in polluting the nation’s waters. Industrial and agricultural runoff

are often equal or greater contributors. But the environmental, aesthetic, and public health impacts of diffuse pollution

will not be eliminated until urban stormwater pollution is controlled.

While urban and suburban runoff continues to be a critical issue, there is substantial evidence that the problems are

not intractable. Increasingly, communities are recognizing the causes and consequences of uncontrolled urban runoff and

taking action to control and prevent runoff pollution, often without any mandate. These innovative communities are

realizing the environmental, economic, and social benefits of preventing stormwater pollution. However, neither the extent

of these efforts nor the specific actions being taken have been well documented.

There is also a growing interest in proposed new federal stormwater regulations. Comprehensive stormwater regulation

is required under Section 402(p) of the Clean Water Act. Since 1992, cities with populations over 100,000, certain

industries, and construction sites over 5 acres have been required to develop and implement stormwater plans under

Phase I of the National Pollutant Discharge Elimination System (NPDES) stormwater regulations (U.S. Environmental

Protection Agency, 1990). In October 1999, EPA is expected to promulgate a new rule requiring municipalities with

populations fewer than 100,000 people located in “urbanized areas” (where population density is greater than 1,000

persons per square mile) to develop stormwater plans. Under what is known as the “Phase II” rule, the EPA and states

will develop “tool boxes” from which the smaller local governments can choose particular stormwater strategies to develop

their stormwater plans (U.S. Environmental Protection Agency, 1998a).

To address all of these issues and concerns, the authors developed a study to examine, document, and disseminate

information on environmentally effective and economically advantageous stormwater pollution prevention strategies. The

study resulted in a report, SformwaferSfrafegies: Communify Responses fo RunoffPollution, that highlights some of the

125
most effective existing stormwater strategies from around the country (Lehner et a/., 1999). The report provides

substantial evidence that such programs exist and highlights a variety of innovative strategies actually being used. The

report also aims to provide guidance to communities addressing stormwater issues, encourage municipal action, and help

empower communities to be involved in this critical issue. This paper summarizes the study and presents its primary

findings and recommendations.

Study Design and Approach

The study was exploratory in nature, with the intent of presenting information on existing effective stormwater

management programs. To achieve this goal, we collected examples of environmentally beneficial and cost-effective

stormwater programs from across the country. We compiled this information into the case-study-based report described

above. This information and report have become the basis for a comprehensive outreach effort.

The first step was to gather information on programs and projects by examining existing programs (several begun

under Phase I as well as many that started earlier), reviewing literature, contacting regional and local stormwater

management experts and researchers, and interviewing representatives from stormwater management or other local

government agencies. We gathered information on over 250 programs. The information was then examined in detail and

narrowed down to a set of case studies that demonstrated elements of success. Three fundamental criteria for selection

were used: environmental gains, economicadvantages, and community benefits. Environmental gains included biological,

hydrological, or chemical improvements resulting from stormwater management. Economic advantages included cost

savings to the municipality or developers, or increases in property values related to the pollution prevention measure.

Community benefits included aesthetic or recreational enhancement, administrative or institutional successes, or

community relations improvements.

Seventy-seven programs and projects were selected as case studies for the final report. Another 88 programs were

annotated to provide additional programs/locations not fully evaluated for the report. The case studies represent

communities of all sizes, types, and regions throughout the United States. To help ensure accuracy, local experts or

people familiar with the program, called “groundtruthers,“were contacted to review the case studies and add information

from their own knowledge and experience.

The case studies were first organized geographically by dividing the United States into six regions based in part on

general rainfall patterns. Within each of the regions, case studies were then further subdivided into five categories of

stormwater management measures including, (1) addressing stormwater in new development and redevelopment, (2)

promoting public education and participation, (3) controlling construction site runoff, (4) detecting and eliminating improper

or illegal connections and discharges, (5) and implementing pollution prevention for municipal operations. These

categories roughly parallel those measures that large municipalities address under existing Federal regulations (40 CFR

parts 122.26 and 123.25) and small municipalities will address under pending Federal regulations (U.S. Environmental

Protection Agency, 1998a).

Case Study Findings

Through reporting over 150 examples of actual programs, the full report provides substantial evidence that stormwater

pollution can be reduced or prevented with proper planning and implementation in growing or re-developing areas. The

examples presented in the report also demonstrate that if some communities can measurably and cost-effectively reduce

stormwater pollution, so can other communities and states (Lehner, et al., 1999).

The Five Categories of Stormwater Management Measures

Individually, the case studies provide detailed examples of substantial water quality improvement, effective or

innovative stormwater control strategies to protect the natural environment, significant cost-savings, and important

ancillary benefits to the community. The programs and strategies highlighted come from communities of all sizes, types,

126
and regions. They include efforts by municipal agencies, developers, and community groups. In many cases, several of

these groups worked together to create win-win outcomes. The case studies highlight a variety of strategies for

addressing the five categories of stormwater management measures previously enumerated, and are described in more

detail as follows.

Addressing Sformwaferin New Development and Redevelopment. By far the most important category of stormwater

strategies focuses on land use and development. It encompasses a wide range of measures including regional or

watershed planning, buffers and open space preservation, infill development, conservation design, and the use of sitespecific structural and nonstructural treatment measures. One of the best strategies a municipality or developer can

employ is to minimize the aggregate amount of new impervious surfaces. For example, developers of the Prairie Crossing

project in Grayslake, Illinois, prevented runoff pollution and saved money by using conservation design strategies. The

developers first reduced impervious cover by clustering 317 residences on only 132 acres of the site, which left 80 percent

as open space. They then designed the developed area around a natural drainage system consisting of vegetated swales,

restored prairie, and wetlands. Modeling indicates that this stormwater treatment drain system will remove approximately

85% of nutrients, metals, and suspended sediments and reduce peak flows by 68%. Eliminating curbs and gutters

resulted in savings of $1.6 to$2.7 million. The development is also very appealing to homebuyers, with sales comparable

to or better than conventional developments in the area (see Lehner et al., 1999, p. 224).

Promoting Public Education and Participation. Individuals play a key role in reducing stormwater impacts both in their

own day-to-day activities and in showing support for municipal programs and ordinances. The most successful highlighted

programs accomplished three goals: they educated the public about the nature of the problem, they informed the people

about what they can do to solve the problem, and they involved citizens in hands-on activities to achieve pollutant

reduction or restoration targets. One example of this success is in Minneapolis, Minnesota, where a decline in water

quality motivated the Lake Harriet Watershed Awareness Project. Monitoring revealed that lawn-care chemicals were a

significant contributor to the problem, which suggested focused education efforts. In turn, the project developed two

approaches: a volunteer master gardener program and the distribution of educational materials. Evaluation showed that

67% of watershed residents reported using the information presented and 30% reported a change in behavior. As a result,

concentrations of lawn-care pesticides have dropped by 50% or more since the program began (see Lehner eta/., 1999,

p. 231).

Controlling Construction Site RunoffI The case studies demonstrate that effective construction site pollution prevention

is politically and economically feasible and can dramatically reduce pollution. The most effective programs rest on four

cornerstones laid in pairs: enforcement and education; erosion prevention and sediment control. However, the first and

over-arching necessity is a clear set of requirements. For example, Herzog et a/. (1998) found that in Geauga County,

Ohio, and St. Joseph County, Indiana, aggressive, widespread seeding and mulching reduced construction site erosion

by up to 86% and reduced phosphorus loadings by 80%. These measures can also benefit developers financially. They

found that homebuyers perceive these “green” lots to be worth $750 more than comparable “brown” lots (see Lehner et

a/., 1999, p. 236). While existing programs employ a wide variety of erosion and sediment control practices, virtually all

successful strategies require proper planning and phasing of construction activities to minimize land disturbance.

Defecting and Eliminafing Improper or //legal Connecfions and Discharges. Local governments have found that

identifying and eliminating illicit connections and discharges is a remarkably simple and cost-effective way to address

some of the worst stormwater pollution. The case studies show that two factors are critical to success of this element of

stormwater programs: finding illicit connections and discharges, and enforcement. In Washtenaw County, Michigan, the

Huron River Pollution Abatement project resulted in a 75% reduction in the river’s fecal coliform levels in just 4 years. The

project focused on eliminating existing illicit connections and preventing future incidents through chemical storage surveys,

industrial inspections, water-quality monitoring, public education, and complaint and spill response. Over a six-year period,

the program dye-tested more than 3,800 facilities, after which 328 of the 450 illicit connections found were removed (see

Lehner et al., 1999, p. 239).

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lmplemenfing Pollution Prevention for Municipal Operations. A wide range of municipal operations can affect

stormwater quantity and quality. The case studies reveal that some local governments have been able to manage their

municipal operations to reduce stormwater pollution. The municipalities highlighted have done so in a variety of ways

including reducing the use of harmful chemicals in the maintenance of municipal properties and vehicles, improving the

maintenance and cleaning of roads and stormwater infrastructure, and training staff in pollution prevention practices.

Several municipalities have taken these steps at their golf courses. For example, the Village Links Golf Course in Glen

Ellyn, Illinois, is preventing runoff pollution by incorporating integrated pest management, water conservation, stormwater

detention, native planting, recycling, and public outreach into its day-to-day management. The golf course relies on both

mechanical and biological pest controls and has significantly increased natural areas. The course collects runoff from

nearby streets and neighborhoods in its system of ponds and spillways. These ponds provide approximately 60% of the

course’s irrigation water, and the course itself passively treats and filters all excess runoff from irrigation (see Lehner et

a/., 1999, p. 243).

Themes Common to Success Stories

Collectively, over 150 case studies present a clear model for success. Evaluation of the case studies revealed several

common elements among the highlighted programs. We distilled those elements into the seven broad themes listed below

to help guide communities as they develop or improve stormwater programs. Since they are based on actual programs,

these themes form a solid foundation for successful programs.

Preventing pollution is high/y effective and saves money. Pollution prevention measures dramatically and costeffectively reduce the quantity and concentration of pollutants “winding up” in stormwater. Common pollution prevention

measures include reducing or eliminating the use of harmful products, preventing erosion, reducing the amount of

pavement in new developments, and changing maintenance practices. In highly urbanized areas, however, such

measures may be difficult. In such cases, several communities have found treatment of runoff with structural measures

or retrofitting existing structures to be effective alternatives.

Preserving and utilizing natural features andprocesses have many benefits. Many communities and developers have

found strategies that rely on natural processes to be highly effective and economically advantageous. Undeveloped

landscapes absorb large quantities of rainfall and snowmelt and vegetation helps to filter out pollutants from stormwater.

Buffer zones, conservation-designed development, sensitive area protection, or encouragement of infill development all

enhance natural processes.

Educafingandinforming fhegeneralpublicandmunicipalsfaffimprovesprograme~ecfiveness. Providing information

and training to the general public and local businesses is a key component to many of the highlighted programs. Since

many sources of stormwater pollution are derived from individual activities such as driving and maintaining homes,

educating the public goes a long way to reducing stormwater pollution. Several communities involve the public in civic

activities, such as monitoring water quality or stenciling storm drains, which not only provide educational opportunities

but also save the municipality money.

Strong incentives, routine moniforing, and consisfenf enforcement establish accountability. Enforcement, or more

broadly accountability, is a key element to improving water quality. All actors need a clear statement of performance

goals, and they need to be held accountable by others for accomplishing these goals. We found that programs with high

accountability were the most effective, often achieving pollutant reductions of 50% or greater.

FinancialsfabilifyheIps ensure effective programs. Effective stormwater programs are financially viable and affordable.

Dedicated funding sources, such as stormwater utilities or environmental fees are equitable ways to build stability into

stormwater programs. Stability and equity are also important in gaining public support. Nearly 200 communities across

the nation are already realizing the benefits of implementing stormwater utilities as dedicated and equitable funding

sources.

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Strong leadership is often a catalyst for success. Success, at least initially, often requires an individual to champion

the project and make it happen.

Hfecfive administration is critical. Regardless of which strategies a community chooses, those programs with clear

goals and objectives are the most successful. Such clarity enhances accountability, responsibility, and trust. Furthermore,

an established and understood institutional framework often improves administration by fostering collaboration among

different parts and levels of government, neighboring communities, and local citizens. Effective administration allows

implementation of broad-based, multi-faceted programs, which are often the most effective at controlling the diffuse

problem of stormwater pollution.

Authors’ Recommendations for Local Action

To further guide communities addressing stormwater runoff issues, we translated the broad themes presented above

into an action plan based on nine key recommendations. These actions roughly parallel the broad themes presented

above. The case studies demonstrated that following the nine local actions outlined below will help build a strong

framework for effective, efficient, and successful stormwater management over the long term.

2)

3)

4)

5)

6)

7)

8)

P/an in advance and set clear goals. Carefully plan programs, as opposed to simply reacting to provided

opportunities, crises, or transient pressures. Planning allows development of more effective and cost-effective

actions. An essential outcome of planning is addressing the issues and concerns of all stakeholders involved.

Encourageandfacilifafe broadparficipation. Program planning, development, and implementation should involve

multiple levels of government, key members of the community, and professionals from a variety of related

disciplines. A key to success is the public’s understanding of the issue, how it relates to them, and what they can

do about it.

Promote public education opportunities. Implement broad-based programs that reach a range of audiences and

solicit different levels of public involvement. Remain committed to the education program and take advantage of

existing community organizations to enhance participation.

Work to prevent pollution first; rely on sfructural treatment on/y when necessary. Focus on prevention-based

approaches, through regional and watershed planning, local zoning ordinances, preservation of natural areas,

stormwater-sensitive site design, and erosion prevention as these are significantly more effective than treatment

of polluted runoff.

Esfablishandmainfain accountability. Essential components of this process are setting clear standards, creating

strong incentives and disincentives, conducting routine monitoring and inspections, keeping the public informed,

promoting public availability of stormwater plans and permits, and consistently enforcing laws and regulations.

Strong enforcement is often key to significant water quality improvements.

Secure financial resources. Consider establishing a dedicated funding source such as a stormwater utility.

Combine with it budget-saving measures such as creative staffing, public-public and public-private collaboration,

and building off existing programs.

Tailorsfrafegies to the region and setting. Recognizing that every case will be different, consider strategies that

are particularly tailored to the region, the specific audience, and the problem.

Evaluate and allow for evolution ofprograms. Set clear goals and priorities, and allow programs to develop over

time. Establish clear ways to check and see that goals and objectives are being met. This opens opportunities

for improvements and helps ensure long-term success.

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9) Recognize the importance ofassociatedcommunitybenefits. Stormwater pollution prevention measures usually

offer ancillary quality-of-life benefits in addition to targeted improvements. For example, preserved areas offer

parks, ponds offer beauty and habitat, clean streets are more attractive, education helps empower people, and

sediment control improves fisheries and prevents flooding.

Conclusion

Many fine handbooks provide theoretical and technical guidance concerning the design and implementation of

effective stormwater pollution prevention and control measures. This study took a different approach and focused on

existing effective programs in a variety of settings. In doing so, it accomplished two key goals. First, the study

’ demonstrates that stormwater management is quite possible. The case studies show on a practical level that stormwater

management can be environmentally effective, economically advantageous, and politically feasible. Second, the case

studies enable communities developing or improving stormwater programs to learn from their peers. In doing so, the case

studies offer an outline for future successful stormwater management strategies.

Acknowledgments

The authors extend their appreciation to all the communities, organizations, agencies, and individuals who provided

information for this study; the technical consultants, peer reviewers, and groundtruthers for their helpful comments; and

the volunteers and Natural Resources Defense Council staff who assisted with this study. The study was supported by

a grant from the EPA under Section 104(b)(3) of the Clean Water Act.

References

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Science and Technology, 28(3-5): 241-259.

Booth, D. B. 1990. Stream-Channel Incision Following Drainage-Basin Urbanization. Water Resources Bulletin, 26(3): 407-417.

Booth, D. B. and L. E. Reinelt. 1993. Consequences of Urbanization on Aquatic Systems-Measured Effects, Degradation

Thresholds, and Corrective Strategies. Proceedings, Watershed ‘93: A National Conference on Watershed Management,

Alexandria VA, pp. 545-550.

Carpenter, S. R., N. F. Caraco, D. L. Correll, R. W. Howarth, A. N. Sharpley, and V. H. Smith. 1998. Nonpoint Pollution of

Surface Waters with Phosphorus and Nitrogen. Ecological Applications, 8(3): 559-567.

Galli, J. 1990. Thermal Impacts Associated with Urbanization and Stormwater Management Best Management Practices: Final

Report. Metropolitan Washington Council of Governments, Washington, DC, 157 pp.

Haile, R. W., James Alamillo, Kevin Barrett, Ron Cressey, John Dermond, Carolyn Ervin, Alice Glasser, Nina Harawa, Patricia

Harmon, Janice Harper, Charles McGee, Robert C. Millikan, Mitchell Nides, John S. Witte, 1996. An Epidemiological Study of

Possible Adverse Health Effects of Swimming in Santa Monica Bay. Santa Monica Bay Restoration Project, Santa Monica, CA,

70 PP.

Herrog, M., J. Harbor, K. McClintock, J. Law, and K. Goranson. 1998. Are Green Lots Worth More than Brown Lots? An

Economic Incentive for Erosion Control on Residential Developments. Journal of Soil and Water Conservation, Accepted.

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Bulletin. 23(6): 1047-l 055.

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Lehner, P. H., G. P. Aponte Clarke, D. M. Cameron, and A. G. Frank. 1999. Stormwater Strategies: Community Responses

to Runoff Pollution. Natural Resources Defense Council, New York, N.Y., 269 pp.

Novotny, V. H. and Harvey Olem. 1994. Water Quality: Prevention, Identification, and Management of Diffuse Pollution. Van

Nostrand Reinhold, New York, 1054 pp.

Schueler, T. R. 1994. The Importance of Imperviousness. Watershed Protection Techniques l(3): 100-l 11.

U.S. Environmental Protection Agency. 1990.40 CFR Parts 122,123, and 124, National Pollutant Discharge Elimination System

Permit Application Regulations for Storm Water Discharges; Final Rule. Federal Register, U.S. Government Printing Office,

Washington, DC 55(222): 47992-47993.

U.S. Environmental Protection Agency, 1997a. Nonpoint Source Pollution: The Nation’s Largest Water Quality Problem.

Accessed December 21, 1998, at URL http://www.epa.gov/OWOW/ NPS/facts/pointl .htm.

U.S. Environmental Protection Agency. 1997b. Urbanization and Streams: Studies of Hydrologic Impacts, Qffice of Water,

Washington, D.C., 841 R-97-009, 15 pp.

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System-Proposed Regulations for Revision of the Water Pollution Control Program Addressing Storm Water Discharged;

Proposed Rule, Federal Register, U.S. Government Printing Office, Washington, D.C., 63(6): 1536-l 643.

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521 pp.

131
Integrated Urban Stormwater Master Planning

Eric Strecker, Vice President

URS Greiner Woodward-Clyde

Portland, OR 97201

Krista Reininga, Sr. Project Engineer

URS Greiner Woodward-Clyde

Portland, OR 97201

Abstract

Urban stormwater management agencies are increasingly being called upon to address water quality and natural

resources issues in addition to their traditional focus on flood conveyance. In response to this, stormwater drainage

master plans have been increasingly addressing stormwater quality and, in limited cases, natural resources and habitat.

This paper will describe some of the problems with traditional stormwater master planning approaches, including those

where water quality and natural resources have been included as “add-ens,” and the urban stormwater problems we are

now trying to address which have resulted from these approaches. A framework for how communities can develop

integrated stormwater master plans that address multiple objectives, as increasingly mandated by public concern as well

as by regulations, will be presented. Given that the tools available for master planning are not equivalent in their

numerical evaluations, new procedures and project approaches are required. Especially important is how the

hydrology/hydraulic methods are performed, including both flood evaluations and evaluation of the smaller channelforming storms.

Communities are often not institutionally organized to address multiple objectives. Master planning has traditionally

been led and performed by engineers trained in hydrology and hydraulics, and they are usually in different departments

from those who are responsible for other environmental aspects of the drainage system. This paper will focus on the

technical, institutional, and process-oriented aspects of how master planning can be improved. Several case studies from

the Pacific Northwest of the United States will be discussed.

Introduction

The purpose of this paper is to discuss some of the attributes of urban stormwater master planning and how those

master plans can be improved to more fully address issues besides conveyance capacity and flood control. Stormwater

master plans go by a number of names, including storm drain master plans, stormwater infrastructure plans, and urban

catchment management plans. These plans are usually very focused on flood control and, until just recently, address

water quality minimally. This paper will discuss some of the attributes of traditional urban stormwater master planning

and its results, regulatory programs (which in the US and New Zealand are requiring adifferent approach), how integrated

master planning can be accomplished, and institutional barriers which often prevent integrated master planning from being

accomplished. In this paper, an Integrated Stormwater Master Plan is an infrastructure and management plan that not

only addresses flood control and property protection issues, but also considers stream stability and habitat, along with

water quality and aesthetics.

Urban Stormwater Drainage Problems

It has long been recognized that in urban areas, unplanned stormwater management systems result in damage to

property and sometimes people. As it will be well demonstrated by other papers in these proceedings, urbanization of

watersheds and the resulting impervious areas also cause changes to the hydrology and water quality of receiving waters

which ultimately result in other impacts to aquatic life and humans. Even some of our measures to control impacts can

have unplanned detrimental effects. Especially sensitive to these changes are stream systems and coastal embayments

132
that are not well flushed. Almost always there are also direct impacts to stream riparian areas which also increase these

changes through canopy removal and channel modifications.

Urbanization usually includes impervious areas directly connected to efficient stormwater conveyance systems

(including roof drains and driveways connected to streets and curbs to inlets to pipes) which then are discharged to

streams directly or through engineered channels. This has resulted in stormwater being conveyed as fast as possible

to receiving waters (and away from properties). Increasingly, it is being recognized that because stormwater is drained

to streams in this manner, small storm hydrological changes that result in increased runoff flows can significantly increase

the frequency and duration of elevated flows. This energy change within the normal wetted channel often results in

channel cutting, widening, and/or sedimentation, which in turn can cause severe habitat and water quality degradation

(MacRae 1996; Sovern and Washington, 1996). Often to “fix” these channel problems, streams are enclosed, hardened,

and/or straightened. Even without considering the water quality of stormwater, our stormwater systems are severely

impacted from a physical habitat standpoint, including habitat loss, higher velocities, and temperature changes. Figure

1 shows an example of how stream runoff can change with urbanization, including much higher and peaky flows as well

as increased volumes of runoff.

Rainfall and Runoff

1.0

0.9

0.8

9.6

c

go.5

m

20.4

K

0.3

Rainfall (in/hr)

- s Post Dev (c=.95)

- - Pre Dev (c=.30)

- Post Dev (with discharge control) . .

0.09

0.08

0.07

0.06

Hours

Figure 1. Example Schematic of Changing Rainfall/Runoff Relationships with Development.

With urbanization also comes a dramatic change in water quality. Urban stormwater systems are the efficient

conveyance system of urban pollutants, both those discharged during storm events and those occurring during dryweather discharges. There are numerous ways that pollutants enter stormwater from those in the rainfall itself to

commonly thought of sources such as street dirt and car drippings. Stormwater often exceeds US EPA water quality

criteria. Figure 2 is a graph of the frequency that stormwater runoff from identified land uses in Oregon exceed US EPA

acute dissolved metals water quality criteria in runoff from identified land uses (Strecker et al., 1997). It should be noted

that most of this runoff was measured in pipes, while the criteria are meant to apply to receiving waters. A data set of

flow-weighted composite samples (representing average storm concentrations) from over 40 land use stations from

various areas of the Willamette Valley was utilized to develop the information displayed in the figure. The stations

included an open land use station in an urban area (Forest Park in Portland) for comparison. Note that dissolved copper

and zinc in developed land uses exceeded criteria for 30 to 65% of the storm events. Similar findings have been found

in other programs, including the San Francisco Bay area programs (Cooke and Lee, 1993).

133
70%

60%

50%

40%

30%

20%

10%

0%

n Open

H Residential

n Commercial

0 Transportation

q Industrial

Cadmium Copper Lead Zinc

Based upon Oregon NPDES Stormwater Monitoring Data

Compiled by ACWA. Developed areas: 27 to 67 storm

events; Open space: 9 storm events

Figure 2. Frequency that Flow-weighted Composite Urban Stormwater Runoff Samples Metals Concentrations Exceeded US EPAs Acute Criteria for

Aquatic Life.

The water quality impacts together with the physical hydrology changes described above have caused our urban

stream systems to become severely degraded. Our traditional systems have not protected the resources nearly as well

as they have protected property. As many have now recognized, at about 10 to 25% imperviousness, the health of the

aquatic system is severely degraded (May et al., 1997; Schueler, 1994). In many cases because of the longer-term

channel stresses, property has been damaged as well, including under cutting of headwalls, etc. The plans typically only

identified solutions that solved large flooding problems, sometimes just temporally until what has been considered

“maintenance” problems such as head wall failures, occur.

Environmental Concerns and Regulatory Requirements

In the US, Congress has recognized that urban stormwater plays a major role in affecting receiving waters when it

mandated in the revised Clean Water Act that urban stormwater water quality be addressed through a permitting

(consent) program. New Zealand has similar requirements through its Resources Management Act of 1991. Both these

programs are still evolving. The stormwater permit program in the US specifically requires that larger cities (over 100,000)

and soon smaller cities address stormwater quality issues as they conduct flood control projects. New Zealand’s program

also requires that municipalities obtain consents for stormwater discharges.

Under the overall program, one area that has been slow to change is how urban stormwater master plans are

developed and implemented. Although there are requirements to consider water quality in conducting flood control efforts,

for a number of reasons (including institutional inertia) agencies have been somewhat slow in actually giving water quality

and habitat protection equal weight with flood control in master planning. Some of this is due to the fact that stormwater

master plans are typically the responsibility of engineers who are experienced in hydraulics, but that often lack experience

and knowledge in other aspects of environmental stormwater management. To be fair, engineers have been told to plan

for managing stormwater based upon land-use zoning that was selected without considering stormwater issues. Another

major issue is the resources allocated to conduct integrated planning efforts which are more expensive; often agencies

do not recognize the value of better up-front planning compared to capital and maintenance costs.

Increasingly though, the public has started to demand that more environmentally sound and/or aesthetically pleasing

stormwater management approaches be utilized. For example, with the endangered species act (ESA) listings and

proposed listings of salmon and trout species in the US Pacific Northwest, many neighborhood organizations are

134
pressuring municipal agencies to change their stormwater management approaches. Some of these efforts are having

more success than the regulatory programs.

Stormwater Management Agency Functions

Understanding a stormwater management agency’s function and history is important to understanding its approach

to stormwater management. Stormwater management agencies typically fulfill the following roles:

1. Stormwater System Maintenance

2. Development Standard

3. Stormwater Master Planning

4. CIP Design and Construction

5. Funding-Utilities/System Development Charges

6. Stormwater System Permitting and Environmental Impact Minimization

7. Education

The last two elements are the most recent. Many agencies began by responding to emergencies and problems, and

were then tasked to develop onsite design conveyance standards. Stormwater master plans for the most par-t were

developed in response to problems that arose after watersheds were developing with little or no stormwater planning.

They also were typically focused on just flood control and property protection. Most often they focused on the piped

systems and road culverts. Often creeks away from culverts were not evaluated unless there had been a particular

problem identified. In the US, the Federal Emergency Management Agency (FEMA) had separately developed flood plain

maps for larger systems, which communities relied upon for protecting structures from larger river and stream flooding.

This was done to meet requirements for participation in FEMA’s flood insurance program. Therefore, flood plains and

the creeks themselves have not been a focus of master plan (e.g., creek sections were typically not evaluated to a great

extent).

Stormwater Drainage Master Plan Goals and Results

The traditional purposes of the Stormwater Drainage Master Plan were to:

l Guide a city’s stormwater drainage system capital improvement project (CIP) program. (e.g., identify, select, cost,

and prioritize stormwater system construction projects.)

l Establish a maintenance program for the stormwater system (recommended stormwater system maintenance

practices and frequencies)

l Establish onsite conveyance requirements (design standards for level of peak flow conveyance by an engineered

stormwater system and, sometimes, requirements for street conveyance of stormwater beyond the onsite

requirements)

Master plans seldom included requirements for development with regard to stormwater system impacts (e.g.,

downstream flow and/or water quality impacts). Master plans were sometimes utilized to assess potential future problems

as well as to fix existing problems. Often systems were evaluated under current conditions and future planned zoning

to be able to assess costs to current rate/tax payers or new developments. Because master plans were not usually

completed prior to some significant level of development, attributing these costs was important to the development

community as well as to the residents.

135
The traditional approach to stormwater master planning has been to focus on hydrology and hydraulics of the existing

stormwater systems, and proposed larger trunk systems to determine whether there is enough capacity. This is usually

is accomplished by the following steps:

. Route a designated large storm through system, assume worst case conditions (saturated, etc.) and determine

capacity deficiencies

l Develop an enlarged (or more efficient) system to handle larger flows or, when necessary, reduce peak flows by

detention (if the cost of detention is less than a conveyance upgrade)

l Sometimes consider water quality as a “add-on” (e.g., if detention is required, claim a water quality benefit)

This approach has certainly significantly reduced property damage (sometimes only for short-term), but has led to

more damage in streams. The damage has been a result of a significant increase and duration in small storm runoff

flows. The result of not planning for this increased energy, which is primarily contained within the stream channel, has

often been an increase in maintenance and property damage. For example, channel cutting that occurs upstream of

culverts often causes headwall and culvert failures. In other areas where channel cut sediments settle out (often in overdesigned or poorly designed culverts), areas are filled in with sediments. When this occurs (especially in a culvert), it can

lead to flooding. These problems (headwall failures, culverts filled in, etc.) are often called maintenance issues, when

they are in fact really failures of the master plan to adequately address stream impacts of development.

Typically smaller urban stormwater systems (e.g., 10 to 50 acre catchments) are dominated from a flooding

standpoint by shorter-duration, more-intense storms (thunderstorms), whereas, the larger urban watersheds are often

impacted by larger, but less-intense storms of longer duration. Master plans typically utilize a single large design storm

event based upon a rainfall depth (mm of rain over a watershed) for a specified duration and return period. This depth

is then assigned a conservative shape such as the SCS type IA shape shown in Figure 3). The storm shown is the 25-

year, 24-hour storm depth for Eugene, Oregon, with the SCS distribution applied to it. As an example of how overly

conservative the peak of

i

Figure 3. 25-Year, 24-Hour SCS Type 1A Synthetic Design Storm for Eugene, Oregon.

136
the “design” hydrograph is, Figure 4 shows an actual 25year storm hydrograph (based upon analysis of the Eugene

Airport rain gage). This storm was confirmed by long-term simulation modeling to have caused approximately the 25-year

return-period flows in the larger stormwater systems in the city. In reality, the 25-year return-period storm depth seldom

if ever arrives with the peaky “shape” given it in master plans.

National Weather Service Rainfall Data for February 5-8,1996

1.8

1.6

Total l%infall Volume = 7.3 in

Max. FGnfall Intensity = 0.66 inJ-rr

=

$! 0.8

.-E

2 0.6

Figure 4. Rainfall Event that was Considered to Cause the Approximately 25-Year Return Period Peak Runoff Flows in Eugene, Oregon.

Many have justified this shape as being one that will also allow flood control effects of smaller thunderstorms on the

smaller stormwater systems to be adequately evaluated. When the peak is modeled in this fashion on a larger watershed

during an already large rainfall, the peak may greatly affect the larger system design. This conservative design approach

we believe has led many communities to determine that streams are undersized and must be widened, channeled, and/or

piped.

Of course in communities where there is the potential for combined phenomenon to cause severe flooding (e.g.,

snowmelt and frozen ground combined with a hard rain), there may be good reason to over size facilities. However, in

most cases, it may be more appropriate to utilize methods that account for this and to strive to preserve open channels

in more natural ways (e.g., larger stream buffers) to the extent possible.

Another assumption that is often made is that the watershed is saturated before the design storm arrives. This

assumption is made to be “conservative.” However, it results in an uneven level of conservatism. This assumption would

tend to lead to the most over-designed conveyance systems in the least paved areas. That is, the saturation assumption

would tend to make systems most over-designed in low-density, single-family areas vs. less over-designed in the

downtown core area. The point here is that the levels of over-design are not consistent, nor targeted to the areas where

the greatest level of protection is desired (highest property value).

137
Finally, water quality, and sometimes habitat, is only now being considered in master planning. This is most often

accomplished by adding water quality to a detention feature or specifically selecting and locating several demonstration

water quality projects. Some communities have chosen to not emphasize habitat by engineering their streams with the

purpose of providing flood conveyance as recreational amenities. The Denver area is a good example of this type of

design. In arid areas, where streams are seasonal or even just storm driven, this may be a good choice for communities.

However, some communities are considering the value of seasonal streams play for downstream resources from a

biological and water quality perspective. For example in Eugene, Oregon, the city has determined that seasonal streams

contain a rich fauna of aquatic invertebrates (WCC, 1995) which likely would benefit the health of downstream systems.

There are a number of reasons why the above approaches have continued to be employed. First, planning that

considers multiple objectives is much more difficult to accomplish, from the technical approaches, due to the need to

involve more parties in decision making. The traditional technical approach described above is straightforward, while

design of more natural systems is not (e.g., pipe flow equations are much easier to utilize then open channel flow in

natural streams). In addition, there are many more people to involve in making decisions than dealing only with

engineered physical structures within the stormwater system. Second, most municipalities are not organized well for the

purpose of urban watershed planning. The City of Portland, Oregon (which has been very progressive in many ways)

still has four separate departments (all in one bureau) that do: 1) facilities planning (stormwater system master planning),

2) site stormwater standards, 3) stormwater quality (permit compliance), and 4) watershed management. Each of these

groups has developed its own plans and programs that have understandably not been very well-coordinated or integrated.

Finally, and probably most important, is that integrated planning studies cost significantly more (on the order of 2 to 4

times as much).

Integrated Storm Drainage Master Plans - Approach

The new approach to stormwater master plans is the integration of flood control, water quality, natural resources, and

aesthetics of stormwater systems. This approach requires significantly more effort and should be thought of as one that

will entail adaptive management. That is, the master plan must include components that allow for changing conditions

as development occurs and the downstream systems react.

In completing a stormwater master plan, it is difficult to achieve “maximums” of flood control, water quality, natural

aquatic habitat, and aesthetics. It is somewhat analogous to the rule that it is hard to get a cheap price, good service,

and high quality. It is our belief that one of the problems with master plans has been a lack of recognition that streams

will change and that the plans should be developed to manage change in a positive fashion.

One of the keys to successful integrated master planning is that the planning approach places the proper emphasis

on the technical and decision-making processes employed. As mentioned above, master plans typically have been driven

by the hydrologic/hydraulic modeling of large storm(s) and usually begin with model data collection and analysis. Figure

5 presents a suggested flow diagram for an alternative way of sequencing the development of a master plan. It begins

by conducting an inventory of all aspects of the stormwater system, including all attributes related to the multiple

objectives mentioned above. The approach suggests utilizing multi-disciplinary teams to review conditions in the field to

look for opportunities for meeting objectives, as well as reviewing existing and suspected future problems. Next, before

any modeling is done, the project team and decision-makers should utilize the collected information to develop goals and

objectives for the plan. Then additional technical analyses, including where and what type of detailed hydrologic/hydraulic

modeling is appropriate, can be decided upon based upon these objectives. We have found this approach sharpens the

focus of modeling so that the model is not “driving” the master plan into solutions that focus primarily on conveyance

upgrades.

In developing an integrated master plan, it is generally understood that the right mix of multi-disciplinary technical

specialists should be involved. In addition, it is important to involve the “right” decision-makers and stakeholders early

in the process. It is also important to agree up-front upon the decision-making process that will be utilized. We have

found that utilizing an agreed upon set of factors to evaluate, select, and rank projects is very useful not only for guiding

the process more objectively, but also to serve as a history of why certain projects were recommended and why others

were not. This is very useful for future decision-makers for two reasons. First, when questioned by others, there will be

138
[ Flooding , I\

Problem/

Opportunity

Identification

Team

Surface Water

Master PlanlCIP

Resources

- gather/assess

information

- updated

inventory of

problems and

opportunities

- problem

definition

options for

resolving problems - selected Capitol

Improvement

- options for Projects (CIPs) ,alyKzkr” modeling enhancements

- Multiple and

- goals, objectives,

and criteria

_ final criteria

- apply criteria single objective

NPDES

Natural Resources

Permitting I

to alternatives solutions

Figure 5. Suggested Integrated Stormwater Master Plan Project Approach.

some backing for why certain decisions were made. Second, as conditions that affect the factors change, selection of

projects can also change in a logical fashion.

The approach we recommend is to evaluate solutions that are primarily single objective rather than those that are

multiple objective. That is, a two-stage decision process is employed to make sure that good single-objective solutions

are not ignored because of the multi-objective nature of the factors. The factors employed include:

l Addresses flooding problems l Meets regulatory requirements

l Addresses water quality pollutants of concern l Implementability

l Meets community amenity objectives

l Habitat value

l Reliability/sustainability

l Other environmental impacts

l Life-cycle costs l Equability

Integrated Storm Drainage Master Plans - Hydrology

Integrated stormwater master planning includes evaluating and considering smaller storm hydrological impacts.

Figure 6 presents a storm-depth frequency curve for Portland, Oregon. The figure demonstrates that storms of a depth

of 1.5 inches and less dominate both the number of storms (more than 95%) and the volume of runoff (over 90%). It is

the smaller storms of about 0.3 to 0.8 inches in depth that change the most in their characteristics. In natural areas of

the Northwest, these often did not result in appreciable runoff or resulted only in slightly elevated flows for a long duration.

However, after urbanization, these storms are causing severe and rapid changes in flow levels with each storm. This kind

of analysis can be used to assist decision makers in deciding what level of water quantity and water quality control is

going to be the most cost-effective in reducing the impacts of urbanization.

The best hydrologic and hydraulic modeling approach for assessing and designing stormwater systems is likely the

use of continuous simulation models using long-term rainfall records to evaluate a system under a wide range of varying

hydrologic conditions. However, this is quite expensive. One of the approaches that we have been taking is to utilize

long-term simulations of stormwater systems to select design storms. We believe that this improves the consistency in

providing design storms that are closer to the level of protection that is being “advertised,“without having to run long-term

simulations. This approach involves using real rainfall data with continuous simulation models (e.g., SWMM) to define

the resulting return frequency of runoff peaks in various parts of the stormwater system. Then, real storms are selected

139
Portland Rainfall Statistics

Figure 6.

-0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 10

% of annual runoff volume

1%

Storm Event Rainfall Depth Analysis for Portland, OR Airport

that resulted in the return period of interest (using a partial duration frequency analysis). These “real” storms are then

utilized to design the system. Figure 7 presents an example of partial-duration frequency evaluation of peak flows in one

of the basins in the Eugene, Oregon area. From this frequency distribution, the storm that was closest to the intended

design level (25year) was selected for design analysis of the system. Figure 8 shows a similar analysis for another basin

in Eugene, along with the design flows from an earlier master plan (which utilized the traditional SCS storm method with

saturated conditions).

What Figure 8 demonstrates is that in this basin, the more traditional approach would have resulted in what is likely

a significant over-design of the system. In most basins, this was found to be the case. However, there were several

basins that were close and a few where the real storm approach resulted in larger designs. Figure 9 and 10 compare

the resulting designs in the Flat Creek basin in Eugene. Note that the real storm approach resulted in fewer and smaller

projects in this basin. This means that the city can utilize more of its scarce resources to complete other types of multiobjective projects. One of the advantages of the use of real storms is that the concept is very easy to communicate to

citizens. In addition, the city has found that some of its channels are over-designed compared to the stated level of

protection, and that they may be able to relax vegetation maintenance requirements to allow for more natural channels.

Overall, the city is finding that allocating sufficient resources to conduct an integrated plan will likely lead to a more costeffective program overall, in terms of multiple benefits.

Integrated Storm Drainage Master Plans - Water Quality

There are a number of stormwater quality models and approaches (Donigian and Huber, 1991). Some are quite

simple and straightforward, while others are much more complex. In general, water quality models currently cannot

accurately predict how pollutants get into stormwater. Although some researchers have made great strides in establishing

sources of pollutants in the urban environment (Pitt, 1993), there still are numerous pollutant sources that are not fully

understood. Most models rely on either some land-use-based concentrations to drive water quality predictions or they

use a build-up/wash-off function to describe pollutant concentrations (Donigian and Huber, 1991).

140
Figure 7. Example Frequency Distribution of Peak Flows in Eugene, OR.

PeakFlow~son

San&Clara-RiiRoadBasinette(h=3OlPcres)

Figure 8. Peak Flow Comparison in Urban Runoff from Eugene, OR.

141
Flat Creek Drainage System

Capital Improvements Proposed in 1990 Master Plan

Using lo-year SCS Synthetic Design Storm

City of Eugene

I I

Enlarged Area

- Open Channel

- Pipe or Cukert

l Transition Between Section

I

Figure 7

Figure 9. Proposed Conveyance System Improvements Utilizing the SCS Type 1A Synthetic Design Storm and Assuming Saturated Conditions.

The build-up/wash-off of suspended solids (TSS) is modeled and then TSS concentrations are utilized to predict other

concentrations for such parameters as phosphorus and heavy metals. The first problem with this approach is that it

assumes that the build-up/wash-off of TSS is much greater than any other source pathway. This has not been found to

be the case (Pitt, 1993). When build-up based/wash-off models are calibrated to real data, the build-up/wash-off function

must be set to be much larger than it really is in order to match actual data. When a source control such as street

sweeping is applied, the model will then significantly overestimate its effectiveness no matter what the assumed street

sweepingefficiency is. This may explain why street sweeping has seldom if ever been found to be as effective as

predicted. The second problem with these models is the assumption that other constituent concentrations can be related

142
Flat Creek Drainage System

Capital Improvements Proposed by Woodward-Clyde

Using lo-year Design Storm of November 23, 1960

City of Eugene

1

Enlarged Area

37cfs

\,.- ., 1 9

. .

‘\,,

. . \

'_

,,.

.i

- Open Channel

- Pipe or Culvert

l Transition Between Section

Figure 10. Proposed Conveyance System Projects Utilizing Selected Real Storms for Design.

to TSS concentrations. Strecker (1997) presented data on TSS vs. metals relationships for Portland, Oregon stormwater

data. Although the correlations were significant (? of .3 to .4), we do not believe that they are high enough to be utilized

without some stochastic functions employed. We believe that many master plans have utilized over-complicated

stormwater pollutant load models that have not represented the actual processes well and have not resulted in better

plans compared to their cost.

Based upon the above, we believe that the proper approach to assessing water quality in master planning is to utilize

land-use based, simpler spreadsheet-based statistical models for water quality assessments and planning. If

hydrologic/hydraulic based solutions are being contemplated then more complex models (such as SWMM) can evaluate

detention times might be called for.

143
There have been a number of attempts to develop a better understanding of how stormwater quality BMPs work and

why (Strecker, 1992; Brown and Schueler, 1997). However, what we know about the effectiveness of stormwater best

management practices in improving water quality and ultimately aquatic health has been questioned with good reason

(Strecker 1994; Urbonas 1995; Maxted and Shaver, 1996). Some of the questions arise from the actual studies and how

they have not been completed as to be very useful in assessing effectiveness. In addition, there have been suggestions

that pollutant removal efficiencies may not be the best way to assess effectiveness (irreducible concentrations, etc.).

Finally, there have been some studies that have shown that downstream of some BMPs (e.g., detention systems),

aquatic invertebrate populations are no different from systems that do not have such in-stream ponds (Maxted and

Shaver, 1996).

What we know is the application of BMPs is an evolving science and that the exact cause and effect relationships

are not well known. However, we do know that BMPs have been effective at reducing concentrations. In cases where

there has been no downstream improvement in aquatic invertebrate health from BMPs, we should ascertain what the

limiting factors are and whether the BMP was able to mitigate some if not all of them before we dismiss a BMP. In

addition, we need to understand whether other attributes of the BMP may be contributing to downstream problems such

as demonstrated downstream temperature impacts (Galli, 1991) of on-line ponds, as well as the interruption of drift of

aquatic invertebrates downstream. It is becoming increasingly clear that within-stream detention systems need to be

very carefully evaluated before they are selected as BMPs. What we will need to do in master planning is to make good

subjective decisions regarding the appropriate application of BMPs for water quality. We do not have the data and models

to do otherwise.

Integrated Storm Drainage Master Plans - Stream Stability/Habitat

Unless a watershed has a great ability to infiltrate stormwater or evaporation is a viable technique, stream hydrology

will change (increased runoff) with development. While there are some great techniques to reduce the changes (e.g.,

Prince Georges Department of Environmental Resources. 1997), in many cases these techniques will not be able to

reduce the increased energy within a stream enough to stop channel cutting and downstream sedimentation from

occurring. A technique that has been employed in an attempt to prevent downstream damage is the requirement that

new development controls runoff from a one- or two-year event such that pre- and post- development peak flows for that

event are equaled. MacRae (1996) has demonstrated that this approach may actually cause more problems then it

solves. It usually leads to shifting over-bank flow energy to the wetted channel, further exacerbating channel down

cutting. Figure 1 demonstrates this. Suppose that the peak in hour 14 was the one-year pre-development flow for this

creek. Maintaining post-development flows to this level would significantly lengthen the time the creek is subject to this

channel-forming flow condition, while reducing over-bank flows. Even setting post-development peak runoff rates to onehalf pre-development, results in significant extended energy in the channel. One would likely have to set a requirement

that the flow rate be one-fourth or one-fifth to have a positive effect. This would require very large detention areas.

In many, if not most cases, we believe that the master plan must include within-stream structures to assist it in

changing with development (Sovern, 1996). That is, the plan must move beyond just getting runoff to a stream and

making sure any culverts in the stream are “right-sized.” Master plans should include a component to design in-stream

structures (habitat friendly ones, of course) and have an adaptive management program for them. This approach has

been successfully applied to the Pipers Creek and Thorton Creek watersheds in Seattle, both heavily urbanized

watersheds. What this can accomplish is much faster and more postive equilibrium for the stream system (e.g., the

increased energy can be utilized to create deeper pools and increased spawning gravels in the pool tailway).

Integrated Storm Drainage Master Plans - Capital Improve Projects (CIPs)

The above integrated stormwater master planning elements will result in changing the traditional definition of what

a CIP is. Traditionally it has been structural controls located within the municipally owned stormwater systems (e.g., the

streets and street drainage structures and at creek crossings, etc.) Now ClPs can include property or property rights

acquisition, buffer areas, protection and enhancement of natural resource sites and preservation of the open channel

drainage system.

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Integrated Storm Drainage Master Plans - Public vs. Private Solutions

Another element of master planning can include the evaluation of the trade-off of requiring private solutions (e.g.,

on-site design requirements) versus implementing public stormwater system measures. Figure 11 shows schematically

that on a watershed basis, one could employ a combination of both to achieve the overall most cost-effective system.

This can be addressed in modeling and cost-estimation for both approaches and then one or some combination

employed.

Public only Combindion

Solutions Alternative

P c ivate only

Solutions

Figure 11. Conceptual Comparison between On-site Private Stormwater Solutions and Public Solutions.

Summary

In summary, urban stormwater management involves a complex set of phenomenon to manage and our stormwater

science is lacking to support solely science-based decisions. Urban stormwater master planning needs to be conducted

as an integrated planning and implementation process that considers water quality, habitat, and aesthetics along with

urban flooding in order to meet increasing regulatory and environmental demands of the public. Typically, BMPs will only

reduce the increase in small-storm hydrology that impacts physical stream habitat and stormwater pollutants; in-stream

stability measures are needed as a part of master planning and urban system. Master planning and implementation

needs to be thought of as an iterative process that will require adaptive management over time. A balanced approach

that places the proper emphasis on problem definition, priority and goal setting, selection of measures/controls,

participation by stakeholders, implementation, and monitoring/feedback/plan refinement is needed.

References

Brown, W., and T. Schueler. 1997. National Pollutant Removal Performance Database for Stormwater Best Management

Practices. Center for Watershed Protection, Silver Spring, Maryland.

Cooke, T. and C. Lee. 1993. Toxicity Identification Evaluations in San Francisco Bay Area Runoff. Proceedings of 66th

Water Environment Federation Conference. Anaheim, California.

Donigian, Jr., A. and W. Huber, 1991. Modeling of Nonpoint Source Water Quality in Urban and Non-urban Areas. US

Environmental Protection Agency, Environmental Research Laboratory. EPA/600/3-91/039, June.

Galli, J. 1991. Thermal impacts associated with urbanization and stormwater management best mangement practices.

145
Metropolitan Washington Council of Governments. Maryland Department of Environment. Washington D.C. 188~~.

MacRae, C. 1996. Experience from Morphological Research on Canadian Streams: Is Control of the Two-year

Frequency Event the Best Basis for Stream Channel Protection ? In: Effects of Watershed Development and

Management on Aquatic Ecosystems. American Society of Civil Engineers. Edited by Larry Roesner. Snowbird, Utah.

Pp 144-l 62.

May, C.R., R. Horner, J. Karr, B. Mar, and E. Welsh. 1997. Effects of Urbanization on Small Streams In the Puget Sound

Lowland Ecoregion. In: Watershed Protection Techniques, 2(4): 483-494.

Maxted, J., and E. Shaver. 1996. The Use of Retention Basins to Mitigate Stormwater Impacts on Aquatic Life. In: Effects

of Watershed Development and Management on Aquatic Ecosystems. American Society of Civil Engineers. Edited by

Larry Roesner. Snowbird, Utah. pp. 494-512.

Prince Georges Department of Environmental Resources. 1997. Low Impact Development Design Manual. Department

of Environmental Resources, Prince Georges County, Maryland.

Pitt, R. 1993. Source loading and management model (SLAMM). National Conference on Urban Runoff Management,

March 30-Apri12, 1993. Chicago, IL.

Schueler, T. 1994. The Importance of Imperviousness. In: Watershed Protection Techniques, l(3): 100-l 11.

Sovern, D., and P. Washington. 1996. Effects of Urban Growth on Stream Habitat. IN: Effects of Watershed

Development and Management on Aquatic Ecosystems. American Society of Civil Engineers. Edited by Larry Roesner.

Snowbird, Utah. pp. 163-l 77

Strecker, E., 1994. Constituents and Methods for Assessing BMPs. Proceedings of the Engineering Foundation Conference

on Stormwater Related Monitoring Needs. Aug. 7-12, Crested Butte, Colorado. ASCE.

Strecker, E.W., Kersnar, J.M., Driscoll, E.D., and Horner, R.R. 1992. The Use of Wetlands for Controlling Storm Water

Pollution. The Terrene Institute. Washington, D.C.

Strecker, E., M. lannelli, and B. Wu. 1997. Analysis of Oregon Urban Runoff Water Quality Monitoring Data Collected from

1990 to 1996. Prepared by Woodward-Clyde for the Association of Clean Water Agencies.

Urbonas, B.R., 1995. “Recommended Parameters to Report with BMP Monitoring Data. J. Water Resources Planning and

Management, ASCE. 121(l), 23-34.

Woodward-Clyde, 1997. Willow Creek Physical, Biological, and Chemical Baseline Report. Prepared by WoodwardClyde, for the City of Eugene.

146
Conservation Design: Managing Stormwater through Maximizing Preventive

Nonstructural Practices

Wesley R. Horner

Environmental Management Center

Brandywine Conservancy

Chadds Ford, Pennsylvania

Unlike conventional methods of stormwater management that prioritize peak rate control to mitigate post-development

downstream flooding effects, Conservation Design first aims to prevent or minimize the creation of stormwater from the

outset. Preventive Conservation Design methods are defined in this paper as those that integrate stormwater

management into the initial stages of project design, instead of waiting to consider them in the final steps of the site

planning process. Mitigative Conservation Design techniques will be explored that use natural processes performed by

vegetation and soil to mitigate unavoidable stormwater runoff impacts once prevention has been maximized to the

greatest extent possible. Underlying these techniques-whether preventive or mitigative in nature-is a comprehensive

perspective of water resources that views stormwater as an asset to be managed, not a waste for disposal.

This paper summarizes a recent project which the Brandywine Conservancy undertook for the Delaware Department

of Natural Resources and Environmental Control, with support from USEPA Section 319 funding. For interested readers,

Conservation Design for Stormwater Management: A Design Approach to Reduce Stormwater Impacts from land

Development (Delaware Department of Natural Resources and Environmental Control with Brandywine Conservancy,

1997) further details all aspects of the Conservation Design program described here. This manual is referenced

throughout this paper and is available by contacting DNREC at 302-739-4411 in Dover DE.

Introduction

Most Stormwater management programs place a heavy reliance on implementation of structural stormwater

managementfacilities: detention basins, conveyance piping and inlet/outlet structures. These facilities-though created

to mitigate negative stormwater impacts by controlling flooding-cannot in and of themselves eliminate adverse impacts

of urban development throughout a watershed. In fact, because these systems fail to acknowledge and plan for critical

system-wide water cycle processes, stormwater management itself can become a problem, rather than a solution. This

is especially true when conventional stormwater management systems are combined with conventional large-lot

subdivision designs.

The negative effects of this type of development and conventional stormwater management have been described in

a variety of recent studies and reports, including the Pennsylvania Handbook of Best Management Practices for

Developing Areas (CH2MHill, 1998) and a variety of other state stormwater manuals; Center for Watershed Protection

publications such as Better Site Design: A Handbook for Changing Development Rules in Your Community (Center for

Watershed Protection, 1998) and Planning for Urban Stream Protection (Schueler, 1995); the Northeastern Illinois

Planning Commission’s Reducing the Impacts of Urban Runoff: The Advantages OfAlternative Site Design Approaches

(Northeastern Illinois Planning Commission, 1997), and Urban Sformwafert3estManagementPracticesforNortheastern

lllinois (Northeastern Illinois Planning Commission, 1993). These effects include:

. Altered site hydrology and reduced groundwater recharge

. Reduced stream base flows

. Altered stream geomorphology (resulting in damaged aquatic habitat)

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. Loss of site area for other uses (e.g.; recreation)

- Single purpose: disregards site resource conservation benefits

. Lack of attention to water quality

. High construction costs

. Maintenance burdens and costs

. Negative visual appearance (e.g., basins often fenced off)

. Limited number of stormwater discharge points

- Less flexibility in design

Conservation Design reflects a totally different philosophy toward land development that integrates stormwater

management into the very core of site design, as opposed to considering it a problem to be resolved after the design has

been completed. This philosophy regards stormwater as a key component of the hydrologic cycle and critical to

maintaining the water balance-and groundwater reserves-for a particular watershed.

Recently we have come to realize that land development’s impacts to water resources are not one-dimensional. They

include, in addition to flooding, the multiple concerns of water quality, groundwater quantity, stream and wetland

characteristics, in-stream habitat, and biodiversity. Therefore, stormwater management and site design must be

approached much more comprehensively. At the foundation of this comprehensive approach lies an understanding of

the relationship between land development and our water resources. In order to better comprehend this relationship, we

must understand the water cycle itself-the amount of rainfall, evapo-transpiration, groundwater infiltration, and

runoff-and how this cycle is affected by the characteristics of an individual site such as soil types, topography, and

vegetation.

The Water Cycle and Landscape Dynamics

Appreciation of the water cycle is especially important to achieve successful, comprehensive stormwater management

(Figure 1). In fact, only through understanding full water cycle dynamics, can we hope to achieve some sort of system

balance and minimize negative stormwater impacts. Figure 2 displays a generic flow chart of the water cycle that

highlights the various components of this cycle and how they are interconnected (Conservation Design for Stormwater

Management, 1997). It is important to appreciate that the system itself is a closed loop: what goes in, must come out.

If inputs to infiltration are decreased by 10 inches, then inputs to surface runoff and/or depression storage must be

increased by this same amount. Furthermore, infiltration outputs must also be decreased: following along on the flow

diagram, the groundwater reservoir, evapo-transpiration and soil moisture elements together will be reduced by this 10

inches, which will reduce stream baseflows.

The logical first step in any discussion of the water cycle is precipitation-h all its various forms. In southeast

Pennsylvania, and indeed throughout much of the Mid-Atlantic states, the climate is relatively humid (Conservafion

Design for Stormwafer Management 1997, based on Hydrosphere 1992 database). Substantial precipitation tends

to be distributed throughout the year in frequent events of modest size. This consistency in rainfall throughout the year

indicates that this region does not have a defined wet or dry season as do other areas of the country. This rainfall

potential throughout the year has significant implications for consideration of stormwater runoff. For example, having

rainfall throughout the year indicates that sediment laden runoff can occur at any time; therefore, it is important to

establish some sort of erosion-controlling groundcover during all seasons of the year.

Also important is the distribution of rainfall by size of event. Based on analysis of 35 years of data from a Wilmington,

Delaware rain gage (Conservation Design for Sforrrwafer Management 1997), it is clear that the precipitation occurs

mostly in small “events” or storm intensities. Ninety-eight percent of the total number of events during this extended

period were classified in the “less than 2 inches” category. Even more important from a water cycle perspective, 96%

of the average annual rainfall volume occurred in storms of less than 3 inches (which is less than the 2-year, 24 hour

148
:.

. :w

Figure 1. The Water Cycle.

storm). This understanding of storm size distribution is critical for a variety of reasons in stormwater management. For

example, if our concern is keeping the water cycle in relative balance, capturing and recharging the 1 - or 2-year storm

as the basis for design will encompass the vast bulk of precipitation and stormwater runoff volumes in the average year

and provide adequate water cycle balance. This leads to very different design criteria than if flooding (peak runoff rates)

is the only concern addressed.

Another key component of the water cycle is the linkage between stormwater infiltration, groundwater recharge and

stream baseflow. As land is developed and impervious coverage increased, less water is recharged to groundwater

aquifers (Thomas Dunne and Luna Leopold’s Wafer in Environmental Planning [Dunne and Luna, 19781 is an

excellent background text in addition to the above referenced reports). As these subtractions continue acre-byacre, development-by-development, their cumulative effects grow larger. Also, as development occurs, more water is

often withdrawn from the underground reserves for drinking, irrigation, or commercial uses, As subtractions are made

from the groundwater reservoir flow, the impact will be seen in the form of a lowered water table and reduced stream

baseflow discharge. Headwater springs and first-order streams-the lifeblood of our stream systems-may even dry up.

The baseflow from headwater zones is critical to maintaining a diversity of aquatic plant and animal life, as well as

terrestrial animals dependent on certain aquatic species for survival. In some cases the groundwater reservoir does not

discharge to a stream, but ratherto a wetland. In these instances, reduced infiltration and a lowered water table ultimately

translate into a loss of wetlands themselves, and an elimination of their rich and vibrant ecological function.

A final component of the water cycle that must be addressed is overland runoff. This is the component most

frequently addressed in conventional stormwater management approaches, for it is the cause of increased downstream

flooding. Three major elements determine the volume and character of stormwater runoff for a given storm intensity: soil

type, land cover (including vegetation and debris), and slopes. Soils vary widely in their ability to infiltrate stormwater and

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. .

. .

Figure 2. Water Cycle System Flow Chart.

minimize runoff and are classified accordingly by the USDA Natural Resources Conservation Service (NRCS) into four

categories based on their permeability rates (Hydrologic Soil Groups A through D, with A having best permeability).

Land cover greatly affects the rate and volume of stormwater runoff and has significant water quality impacts as well.

Obviously, the landcover of greatest concern for stormwater management is impervious coverage created through the

development process. Interestingly, compacted lawns and cultivated fields can have significant runoff rates as well,

especially when no crop covers the bare soil. The landcover in this region best suited to retard stormwater runoff and

assist in its infiltration is the natural one: the Piedmont forest. A mature forest can absorb much more water than an

equivalent area of turf grass due to the presence of an organic litter layer and herbaceous and woody plant material. The

organic litter layer on the forest floor provides a physical barrier to sediments, maintains surface soil porosity, and assists

in denitrification and other water quality functions. The vegetation, both herbaceous and woody, physically retards runoff

and erosion with its spreading root mats and also assists in maintaining soil permeability and water quality by taking up

nutrients through its root systems.

Finally, slopes are another critical component of the stormwater runoff equation. Steeper slopescan accelerate runoff

and increase the erosive force of the water. Therefore, removing vegetation on steeper slopes can have dramatic impacts

on downslope aquatic systems.

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As seen above, the water cycle and the implications for stormwater management are complex and comprehensive.

The process of urbanization dramatically impacts the functioning of this water cycle. Conservation Design has been

developed to address the issues of comprehensive stormwater management and to address the land use patterns that

impact it.

Land Use and Site Development Impacts

Throughout much of the United States, farmland and natural areas are converted to suburban development at an ever

accelerating pace. In fact there is hardly a city in America that does not occupy at least two to three times more land area

than in 1970, even if population has not increased proportionately. This history of land use change is certainly true of the

Mid-Atlantic states, where communities continue to grapple with the effects of unmitigated suburban sprawl.

The dynamic nature of wet-weather flow regimes and landscape ecology make it difficult to assess the impact of

urbanization on aspects of the water cycle such as groundwater reserves and aquatic habitat. However, studies have

indicated that the biological community in urban streams isfundamentallychanged to a lower ecological quality than what

was there before development occurred. In one study in Delaware, approximately 70% of the macroinvertebrate

community found in streams of undeveloped forested watersheds was comprised of pollution sensitive mayflies,

stoneflies, and caddisflies, compared to 20% for urbanized watersheds (Maxted and Shaver 1996). Other studies suggest

that the decay in stream quality is very rapid in the early stages of watershed urbanization; watersheds with less than 10%

impervious cover are the most susceptible to the adverse effects of urbanization. Therefore early intervention as a

watershed begins to develop is critical, and furthermore, this intervention should include measures to address stormwater

management and land use in a connected, comprehensive manner.

In addition to in-stream habitat impacts, the issue of land development and water resources also has great

implications for our human communities well beyond the issue of flooding. Reduced stream baseflows and groundwater

resources means decreased availability of drinking water supplies. Also, reduced baseflows result in less available water

for diluting the pollution output from industrial or municipal waste systems. As stormwater runoff increases, water quality

can be greatly impacted by stream bank erosion, resuspension of sediment, runoff of chemicals and fertilizers from lawns

and fields, and increased stream temperatures. Stormwater-linked pollutants vary with type of land use and intensity of

use and have been shown to include bacteria, suspended solids, nutrients, hydrocarbons, metals, herbicides and

pesticides, toxins and organic matter. Not only are these pollutants increased, but the landscape’s natural capacity for

filtering and chemical uptake through vegetation is decreased as land is cleared and paved. All of these pollutants can

impact both drinking water supplies and natural aquatic systems.

Thus it becomes evident that if the negative effects of land development on our water resources are to be minimized,

we must find alternatives to the conventional structural approach to stormwater management. Moreover, these

alternatives must address the issue of land use and patterns of development in a comprehensive fashion, one that strives

to maintain a hydrologic balance on site and replicate the pre-development hydrologic regime to the greatest extent

possible. One approach-or collection of approaches-that can accomplish these goals is Conservation Design.

Conservation Design Principles

Stormwater management throughout the Commonwealth (and elsewhere) can be markedly improved by approaching

stormwater differently than has been the practice in the past, where “stormwater management” has been defined largely

as stormwater disposal. This different perspective challenges us to maximize prevention, even before stormwater

becomes a problem, and to avoid highly engineered structural solutions that are expensive to build and maintain. In their

place, Conservation Design focuses on utilization of natural systems and processes to achieve stormwater management

objectives where feasible. At the same time, this new approach is intended to work with site resources-woodlands, soils,

wetlands, etc.-to enhance their stormwater functions. The end result is a site design which minimizes stormwater

generation and then mitigates the remaining stormwater in a low-impact manner, with an emphasis on groundwater

recharge. Conservation Design is not so much a singular approach or solution as it is a collection of approaches and

practices that are flexible enough to effectively address any given site and development program. Common to all these

approaches and practices are several basic principles.

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Achieve multiple objectives. Stormwater management should be comprehensive in scope, with techniques

designed to achieve multiple stormwater objectives. These objectives include both peak rate and total volume control

(i.e., balance with the hydrologic cycle), as well as water quality control and temperature maintenance. These objectives

should include maintaining or improving the pre-development hydrologic regime.

Integrate stormwater management early into the site design process. Stormwater management tacked on at

the end of the site design process almost invariably is flawed. To optimize comprehensive stormwater management

objectives, stormwater management must be integrated into the first stages of the site planning. Stormwater impacts may

even be a factor in determining ~ of use, extent of use, and location of the development on a site.

Prevent first, mitigate second. Approaches to site design which can reduce stormwater generation from the outset

are the most effective approach to stormwater management. For example, effective clustering of units significantly

reduces length of roads when compared to conventional development. Reduction in street width and driveway length can

minimize impervious coverage. These type of approaches are rarely thought of as stormwater management practices,

yet they achieve powerful stormwater quality and quantity benefits.

Manage stormwater as close to the source of generation as possible. From both an environmental and

economic perspective, redirecting runoff back into the ground as close to the point of origin as possible, is preferable to

constructing elaborate conveyance systems that increase flows and suffer from failures over time. Avoid concentrating

stormwater. Disconnect, rather than connect, where feasible.

Engage natural processes in soil mantle and plant communities. The soil mantle offers critical groundwater

recharge conveyance and pollutant removal functions through physical filtration, biological action, and chemical

processing. Understanding how much of what tape of soil is in place on any given site is essential when assessing

stormwater management/water quality impacts and opportunities. Vegetation similarly provides substantial pollutant

uptake/removal potential and can assist in infiltration by maintaining soil porosity and retarding runoff. In addition,

naturally vegetated areas improve their stormwater functions over time as leaf litter and debris builds a richer organic soil

layer. Areas of good soil permeabilities (A and B soils) and intact vegetative communities should be prioritized in

prevention strategies.

A Conservation Design Procedure

The Conservation Design principles outlined above, though greatly simplified, can offer valuable guidance when

approaching a particular land development project. In fact, these five principles form the basis for a Conservation Design

Procedure. This Design Procedure incorporates both Preventive Approaches and Mitigative Practices. Preventive

Approaches tend to be broader in geographic scope than other techniques and typically may influence some of the major

decisions regarding a particular development project. Approaches may even transcend the site itself, involving an entire

planning jurisdiction or area, or even an entire region. Also, Preventive Approaches attempt to reduce impervious

coverage or minimally disturb the existing vegetation and soils in prime recharge areas. For example, a reduction in road

width from 30 feet to 18 feet means an immediate 33.3% reduction in roadway imperviousness, which typically comprises

a large portion of site imperviousness.

Mitigative Practices include mitigative techniques which are often more structural in nature. These practices

encompass a rapidly growing array of biofiltration and bioretention methods that maximize the stormwater management

potential of soils and vegetation. Mitigative Practices include vegetated swales for stormwater conveyance, vegetated

filter strips and riparian buffers, grading, berming, terrraforming, and level spreading stormwater in natural areas. These

practices should mitigate as close to the source as possible and achieve multiple objectives. For example, a berm, which

is used to retain stormwater runoff on a forested slope, can double as a walking trail, thus decreasing the expense of two

separate individual systems.

Figure 3 graphically displays the Design Procedure as a flow diagram. The procedure itself can be thought of as a

series of questions which must be asked as Conservation Design is applied to each site. If site designers rigorously

address all of these questions, the “answers’‘-the Conservation DesignPreventive Approaches and Mitigative

152
Figure 3. A Conservation

Conservation Design Procedure

Site Analysis

Prevention

,

Conceptuat

Stormwater .

Management

Plan

iJl3 CalCUlaHOti Sizing

ttrny Controls Of

Design Procedure.

153
Practices-will successfully be identified for each site. The overriding objective ultimately is to achieve a new way of

thinking about site design. The procedure begins with an effective and complete Site Analysis, which can help identify

both areasof concern and resourcesforopportunity in regard to stormwater management. The procedure then flows from

macro, larger-scale preventive questions (i.e., how can the design be clustered to reduce site disturbance) to micro, smallscale mitigative questions (i.e., can stormwater be infiltrated in bioretention areas?). Probably the most important aspect

of the procedure in Figure 3 is its positioning of the Conceptual Stormwater Management Plan as a concurrent task with

the entire site design process. This reinforces the notion that stormwater management should be an integral part of the

entire design process, including the site analysis.

In order to better understand the Conservation Design Procedure, each of its components (the Preventive Approaches

and Mitigative Practices) is discussed in more detail below.

Site Analysis

Three major aspects need to be addressed in the Site Analysis process:

Site Background and Context

What is the surrounding context?

What is its location in the watershed?

In which geologic/geographic region is it located?

What is the site size?

What are adjacent uses and landcover?

Critical Natural Features

Existing hydrology?

Wetlands? Floodplains? Riparian buffers?

Steep slopes? Special habitat areas?

Stormwater Opportunity Areas

Where are soils that are best suited for stormwater recharge? Worst?

Where is existing landcover optimal to prevent stormwater?

What opportunities exist to use vegetation and soils in mitigation?

On what soils and slopes is this vegetation?

What is depth to bedrock or water table?

Preventive Approaches

The Preventive Approaches include a range of hierarchical questioning:

Building Program

What is the current zoning and density for this tract?

154
Is there currently an open space design option for the site?

Can the proposed building program be reduced in terms of density?

Can the type of unit or lot size be modified to promote open space?

What are the possibilities for water and sewer supply?

Lot Configuration

Have lots been reduced and open space been maximized?

Have lots been clustered to avoid critical areas of recharge?

Have lots been configured to take advantage of mitigative practices?

Impervious Coverage

Has development been clustered to reduce impervious surfaces?

Have road widths been minimized?

Have building setbacks been minimized to reduce driveway lengths?

Have parking ratios and needs been carefully examined?

Have needs and sizes of walkways been examined?

Minimum Disturbance

Has maximum total site area, including soils and vegetation, been protected from clearing and

disturbance?

Are zones of undisturbed open space maximized?

Have buildings been sited carefully to reduce vegetation removal?

Can no-disturbance buffers be installed to limit zones of soil compaction?

Mitigative Practices

The Mitigative Practices include a tool box of options that promote groundwater recharge and improve water

quality. These practices have been assigned to several groupings, although in many cases the practicesoverlap.

Virtually all of these techniques make maximum use of vegetation and soil functions, so although they are all

technically structures, they are of lower complexity and more rooted in natural process than conventional

approaches.

Vegetated Swales

Vegetated swales are effective means of stormwater conveyance. At low slopes, they can recharge

modest amounts of stormwater, filter it through vegetative processes, and slow it down.

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Terraforming

Terraforming comes in a variety of techniques. These include constructing subtle berms along contour

below undisturbed areas. The berms act as modest “dams” retaining the water for up-slope recharge.

Also, subtle grading of depression areas promote retention and recharge throughout a site.

Level Spreading/Natural Areas

With a level spreader, stormwater spills over the lip of a long trench or berm, creating sheet flow across

a broad area. The level spreaders slow down the intensity of runoff and discharge it over a large,

adjoining vegetated area with good soils, which in turn filter it and assist in groundwater recharge. Filter

strips are planted vegetated strips through which runoff passes that filter it and slow it down. Riparian

buffers are vegetated zones along stream corridors that filter the stormwater passing through it and help

minimize erosion. These techniques are most valuable when used in conjunction with preventive

strategies that leave larger natural areas undisturbed in order to handle these additional stormwater

inputs.

Bioretention/biofiltration

Bioretention is a popular name given to just about any type of device that utilizes vegetation and soil to

manage stormwater flows. They can be subtle depressions that exist naturally and receive stormwater

or depending on soil conditions, they may be physically constructed “pits” that are filled with permeable

soils and planted with native vegetation that adapt to both wet and dry conditions. These systems can

either be “on-line” (part of the stormwater conveyance flow) or “off-line” (separate from the rest of the

stormwater management/mitigation system). In either case, they have modest ponding storage that is

recharged over the course of time.

Other mitigative devices

Not all of the required volume storage to meet peak rate requirements for a given site may be attained

through the practices outlined above. At times, it may be necessary to put in “structural” systems such

as in-ground infiltration trenches, infiltration pipes, or stormwater wetlands. However, these systems

should be explored only after both Preventive Approaches and Mitigative Practices of Conservation

Design have been maximized to the greatest extent possible.

Conclusion

The Conservation Design Procedure is perhaps best characterized as a “check list” or protocol of questioning during

the site design process. The key to this approach is its range of innovative, yet effective options, not afforded in

conventional systems which tend to be standardized irrespective of the particular site. With Conservation Design, the

approaches and practices can be combined in a variety of ways to minimize the impacts of development on the water

cycle and still meet regulatory stormwater management criteria such as peak rate control. Often, because these

approaches and practices tend to favor multiple objectives and nonstructural techniques, Conservation Design can be

less expensive to install and maintain than conventional systems. Also, because they are largely based on soil and

vegetative processes, conservation design techniques tend to improve in function overtime, while conventional detention

basin systems tend to diminish in function over time. In terms of water quality, Conservation Design Approaches and

Practices can outperform conventional systems. For example, filter strips and biofiltration areas can remove over 90%

of the suspended solids, 40% of the phosphorous, and 20% of the nitrates (Dillaha et al. 1986 and 1989; Yu et al. 1993).

In addition, reduced yard areas and increased forested zones prevent chemical runoff from lawns-a great contributor

to non-point source pollution-at the outset.

Conservation Design is limited only by the creativity of the designer and the flexibility of the developer and regulatory

agencies. It must be emphasized that the Conservation Design approach will not eliminate a need for structural systems

in all cases; however, more often than not, Conservation Design can replace or reduce the need for structural practices

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while providing attractive site amenities. And in the process, the water cycle will be balanced, and forests and other

sensitive resources will be preserved. In short, Conservation Design can do more with less, and more for less, than

conventional approaches to stormwater management.

References

Center for Watershed Protection, 1998; Better Site Design: A Handbook for Changing Development Rules in Your

Community; Elliot City, MD.

CH2MHill, 1998; for the Pennsylvania Association of Conservation Districts, Inc., and other agencies; Pennsylvania

Handbook of Best Management Practices for Developing Areas; Harrisburg, PA.

Delaware Dept. of Natural Resources and Environmental Control with the Brandywine Conservancy, 1997; Conservation

Design for Stormwater Management: A Design Approach to Reduce Stormwater Impacts from Land Development; Dover,

DE.

Dillaha, T.A., J.H. Sherrard, and D. Lee, 1986; Long-term Effectiveness and Maintenance of Vegetative Filter Strips;

Virginia Water Resources Research Center Bulletin No. 153; Blacksburg, VA.

Dunne, Thomas and Luna Leopold, 1978; Water in Environmental Planning; W.H. Freeman and Company; New York,

NY.

Northeastern Illinois Planning Commission, 1993; Urban Stormwater Best Management Practices for Northeastern Illinois;

Chicago, IL.

Northeastern Illinois Planning Commission, 1997; Reducing the Impacts of Urban Runoff: The Advantages of Alternative

Site Design Approaches; Chicago, IL.

Schueler, Tom, 1995; Center for Watershed Protection; Site Planning for Urban Stream Protection; Silver Spring, MD

(relocated to Ellicott City).

Yu, S., S. Barnes, and V. Gerde; 1993; Testing of Best Management Practices for Controlling Highway Runoff; Virginia

Transportation Research Coundil; FHWA/VA 93-R16.

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Low-Impact Development Design: A New Paradigm for Stormwater

Management Mimicking and Restoring the Natural Hydrologic Regime

An Alternative Stormwater Management Technology

Larry S. Coffman, Associate Director

Department of Environmental Resources

Prince George’s County, Maryland

Abstract

Whether complying with federal or state regulations or addressing local vital watershed protection/restoration

objectives, local jurisdictions are confronted with the daunting task of developing, administering and funding complex

effective multi-objective stormwater management programs, Today’s comprehensive stormwater program not only has

to deal with runoff quantity and quality control but, may also have to address such complicated issues as ecosystem

restoration, combined sewer overflow reduction, fisheries protection, potable surface/ground water source protection, and

wetland, riparian buffer and stream protection. As our understanding of the technical and practical limitations of

conventional stormwater management technology has increased over the past two decades, and as watershed protection

objectives have changed, many jurisdictions have begun to question the efficacy and cost-effectiveness of conventional

stormwater approaches in meeting today’s complex environmental/water resources objectives. Older communities with

existing extensive stormwater management infrastructures are also struggling with the economic reality of funding the

high costs of maintenance, inspection, enforcement and public outreach necessary to support an expanding and aging

infrastructure. Still more challenging are the exceptionally high costs of retrofitting existing urban development using

conventional stormwater management end-of-pipe practices to restore and protect receiving waters and living resources.

With growing concerns about the limitations of conventional technology and to address the changing objectives of

watershed protection, in 1990 Prince George’s County’s Department of Environmental Resources (PGDER) began

exploring alternative stormwater management practices and strategies. The development of bioretention or “Rain

Gardens” (using the green space to manage runoff within small depressed landscaped areas) led to an understanding

of how to optimize and engineer the landscape to restore hydrologic functions by uniformly integrating micro-scale

management practices and impact-minimization measures into the development landscape. In 1997 PGDER released

the Low Impact Development (LID) Design Manual demonstrating the principles and practices of LID to create a

hydrologically functional landscape (PGDER, 1997).

LID stormwater management technology can maintain or restore a watershed’s hydrologic regime by fundamentally

changing conventional site design to create an environmentally and hydrologically functional landscape that mimics natural

hydrologic functions (volume, frequency, recharge and discharge). This is accomplished in four ways. First: minimizing

impacts to the extent practicable by reducing imperviousness, conserving natural resources and ecosystems, maintaining

natural drainage courses, and reducing the use of pipes and minimizing clearing/grading. Second: recreating detention

and retention storage dispersed and evenly distributed throughout a site with the use of open swales, flatter slopes,

depression storage, rain gardens (bioretention), water use (rain barrels), etc. Third: maintaining the predevelopment‘time

of concentration” by strategically routing flows to maintain travel time. Fourth: providing effective public education and

socioeconomic incentives to ensure property owners use effective pollution prevention measures and maintain

management measures. With LID, every site feature is multifunctional (green space, landscaping, grading, streetscapes,

roads and parking lots) and helps to reduce stormwater impacts or provide/maintain beneficial hydrologic functions. The

cumulative beneficial impact of using the wide array of distributed LID techniques allows the site designer to maintain or

restore watershed’s natural relationship between rainfall, runoff, infiltration and evaporation.

The effective use of LID site design techniques can significantly reduce the cost of providing stormwater management.

Savings are achieved by eliminating the use of stormwater management ponds, using less pipe, inlet structures, curbs

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and gutters, less roadway paving, less grading and clearing. Where LID techniques are applicable, and depending on the

type of development and site constraints, stormwater and site development design construction and maintenance costs

can be reduced by 25 % to 30% compared to conventional approaches.

The creation of LID’s wide array of micro-scale management principles and practices has led to the development of

new tools to retrofit existing urban development. Micro-scale management practices that filter, retain and detain runoff

can be easily integrated into the existing green space and streetscapes as part of the routine maintenance and repair of

urban infrastructure. LID retrofit techniques may lead to drastic reductions in the cost of retrofitting existing urban

development. Reducing urban retrofit costs will increase the ability of cities to implement effective retrofit programs to

reduce the frequency and improve the quality of CSOs and improve the quality of urban runoff to protect receiving waters.

LID represents a radically different approach to controlling stormwater runoff that provides effective tools to restore or

maintain a watershed’s hydrologic functions for new or existing development.

In 1998 EPA provided grant funding to assist PGDER in their efforts to develop a general manual describing LID

principles and practices, and share this technology with other local governments throughout the nation. Efforts are

currently underway with EPA to further advance LID technology by improving the sensitivity of current hydrology and

hydraulic analytical models for application with small watersheds and sites and to develop new micro-scale control

approaches and practices for urban retrofit. Additional efforts are also underway to demonstrate how LID micro-scale

management and multifunctional infrastructure principles and practices can be used to control highway runoff within

existing rights-of-way. It is hoped that the LID national manual will help to stimulate debate on the state of current

stormwater, watershed protection and restoration technology and its future direction. The lessons learned about LID

planning, principles, practices and research are described in detail in the reference documents listed at the end of this

paper. Copies of these reference documents can be obtained by calling the Prince George’s County’s Department of

Environmental Resources at (301) 883-5832.

Background

Typically, adverse stormwater impacts are mitigated through conservation of natural resources (forests, streams,

floodplains and wetlands); zoning restrictions to direct densities and increase open space; and the use of structural or

non-structural control technologies (best management practices - BMP’s) to treat and manage runoff quantity and quality.

Many conventional stormwater mitigation approaches, such as management ponds, exhibit a number of inherent practical,

environmental and economic limitations including inability to replicate predevelopment watershed hydrology, elevated

water temperatures, costly maintenance burdens, and accelerated stream erosion due to the increased duration and

frequency of runoff events. Furthermore, because current mitigation practices only lessen development impacts, there

is concern about the cumulative impacts of the widespread use of conventional mitigation practices that may

fundamentally alter a watershed’s hydrologic regime and water quality, adversely affecting receiving waters and the

integrity of their ecosystems. Many highly urbanized jurisdictions are beginning to question the efficacy of current

technology and are finding it harder to ensure, enforce or fund stormwater programs and maintain the massive

infrastructure created by conventional approaches.

Currently every site is designed with one basic overriding goal - to achieve good drainage. As we develop a site

reshaping the landscape inch by inch, its hydrologicfunctionsare altered on a micro-scale level. The cumulative impacts

of micro-scale changes to the landscape drastically alter watershed hydrology. If sites can be designed to achieve good

drainage, destroying natural hydrologic functions, why not design sites with the opposite objective to maintain

predevelopment hydrologic functions? If inch by inch, sites are carefully and intelligently engineered to maintain hydrologic

functions, would the cumulative beneficial affects result in the preservation of a watershed’s hydrology? Can a site be

designed in a way to remain as a functional part of a watershed’s hydrological regime? To achieve a hydrologically

functional development there must be a radical change in our thinking. We must not think in terms of impact mitigation

as the stormwater management objective, but rather preservation of hydrologic and environmental functions. We should

design sites to maintain hydrologic functions not just to mitigate impacts. Can our current stormwater management

technology adequately meet our regulatory objectives and water resources/ecosystem protection needs? No one can

answer that question for sure. However, it has not been shown that conventional ponds replicate predevelopment

hydrology nor is there any evidence to suggest that conventional technology can ensure the ecological integrity of

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ecosystems. In fact, recent studies suggest that conventional approaches can not meet our water/natural resources and

ecological objectives.

Introduction

With growing concerns about the economicsand efficacy of conventional technology, in 1990 Prince George’s County

Maryland’s Department of Environmental Resources began exploring alternative stormwater management practices. The

success that was achieved through the development and use of bioretention (filtering or infiltration runoff in small

depressed landscaped areas) led us to understand that perhaps changing the form and function of the developed

landscape could be important in mitigating urban stormwater impacts. Later it was realized that through intelligent site

design and uniform distribution of LID micro-scale management controls it was possible to maintain or restore hydrologic

functions in a developed watershed. What is not known is how much of a watershed’s hydrologic functions can be

maintained or restored within a given development type (residential, commercial or industrial)? The one limiting factor to

maintaining/restoring the hydrologic regime for highly urbanized development is the lack of available micro-management

tools. Much of the current research underway is to expand the number of practices applicable in highly urbanized areas.

LID’s objective is to preserve the natural predevelopment hydrologic regime. If predevelopment hydrology and water

quality can be maintained, this would provide the best level of protection possible to receiving waters and aquatic living

resources. Experience over the last 20 years has demonstrated that maximizing the efficiency of conventional

conservation measures and the use of conventional end-of-pipe stormwater management practices can not reasonably

be used to restore watershed functions. What is needed is a new philosophical approach to site development, an

approach that will allow the designer to retain a site’s hydrologic functions.

The approach used in LID designs is really an old one. LID borrows its basic principles from nature - uniform

distribution of micro-management controls. In a natural setting, stormwater is controlled by a variety of mechanisms

(interception by vegetation, small depression storage, channel storage, infiltration and evaporation) uniformly distributed

throughout the landscape. LID mimics these mechanisms by uniformly distributing small infiltration, storage, and retention

and detention measures throughout the developed landscape. What we soon began to see is that every development

feature (green space, landscaping, grading, streetscapes, roads, and parking lots) can be designed to provide some type

of beneficial hydrologic function.

Low - Impact Development General

LID controls stormwater at the source creating a hydrologically functional landscape that mimics natural watershed

hydrology. Low impact development (LID) achieves stormwater management controls by fundamentally changing

conventional site design to create an environmentally functional landscape that mimics natural watershed hydrologic

functions (volume, frequency, recharge and discharge). LID uses four basic management planning and design principles.

First: minimize impacts to the extent practicable by reducing imperviousness, conserving natural resources/ecosystems,

maintaining natural drainage courses, reducing use of pipes and minimizing clearing and grading. Second: provide runoff

storage measures dispersed uniformly throughout the landscape with the use of a variety of small decentralized detention,

retention and runoff practices such as bioretention, open swales and flatter grades. Third: maintain the predevelopment

time of concentration by strategically routing flows to maintain travel time and control discharge. Fourth: implement

effective public education and incentive programs to encourage property owners to use pollution prevention measures

and maintain on-lot landscape management practices. A developed site can be designed to become a hydrologically

functional part of the watershed with comprehensive and intelligent use of LID practices and principles.

LID Basic Site Planning Strategies

The goal of LID is to design the site in a way that mimics hydrologic functions. The first step is to minimize the

generation of runoff (reduce the change in the runoff curve number (CN)). In many respects, this step is very similar to

traditional techniques of maximizing natural resource conservation, limiting disturbance and reducing impervious areas.

The major difference with LID is you must carefully consider how best to make use of the hydrologic soil groups and site

topography to help reduce and control runoff. These considerations would include how to:

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1. maintain natural drainage patterns, topography and depressions,

2. preserve as much existing vegetation as possible in pervious soils; hydrologic soil groups A and B,

3. locate BMP’s in pervious soils; hydrologic soil groups A and B,

4. where feasible construct impervious areas on less pervious soil groups C and D,

5. disconnect impervious surfaces,

6. direct and disburse runoff to soil groups A and B,

7. flatten slopes within cleared areas to facilitate on-lot storage and infiltration and

8. re-vegetate cleared and graded areas.

Where ground water recharge is particularly important (to protect well, spring, stream and wetland flows) it is

important to understand the source and mechanisms for ground water recharge. When using the LID design concepts

to mimic the hydrologic regime you must determine how and where ground water on the site is recharged and where

necessary, protect and utilize the recharge areas in the site.

LID Hydrologic Analysis/Response

The objective of LID site design is to minimize, detain and retain the post development runoff volumes uniformly

throughout the site close to the source to simulate predevelopment hydrologic functions. Widespread use and uniform

dispersion of on-lot small retention and/or detention practices to control both runoff discharge volume and rate is key to

better replicating predevelopment hydrology. Using LID practices also produces runoff frequencies that are much closer

to existing conditions than can be achieved by typical application of conventional BMP’s. Management of both runoff

volume and peak runoff rate is included in the design. This is in contrast to conventional end-of-pipe treatment that

completely alters the watershed hydrology regime.

The LID site analysis and design approach focuses on four major hydrologically based planning elements. These

fundamental factors affect hydrologic and are introduced below.

1. Curve Number (CN) - A factor that accounts for the effects of soils and land cover on amount of runoff generated.

Minimizing the change in the post development CN by reducing impervious areas and preserving more trees and

meadows to reduce runoff storage requirements, all to maintain the predevelopment runoff volume.

2. Time of Concentration (Tc) - This is related to the time runoff travels through the watershed. Maintaining the

predevelopment Tc reduces peak runoff rates after development by lengthening flow paths and reducing the use

of pipe conveyance systems.

3. Permanent storage areas (Retention) - Retention storage is needed for volume and peak control, water quality

control and to maintain the same CN as the predevelopment condition.

4. Temporary storage areas (Detention) - Detention storage may be needed to maintain the peak runoff rate and/or

prevent flooding.

Minimizing the Change in CN

Reducing the change in CN will reduce both the post development peak discharge rate and volume. Calculation of

the LID CN is based on a detailed evaluation of the existing and proposed land cover so that an accurate representation

of the potential for runoff can be obtained. This calculation requires the engineer/planner to investigate the following key

parameters associated with LID including:

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1. land cover type,

2. percentage of and connectivity of impervious cover,

3. hydrologic soils group (HSG), and

4. hydrologic conditions (average moisture or runoff conditions).

The following are some of the LID site planning practices that can be utilized to achieve a substantial reduction in the

change of the calculated CN:

1. narrower driveways and roads (minimizing impervious areas),

2. maximized tree preservation and/or afforestation,

3. site finger-printing (carefully siting lots/roadways to avoid disturbance of streams, wetlands and other resources),

greater use of open drainage swales,

4. preservation of soils with high infiltration rates to reduce CN,

5. location of BMP’s on high-infiltration soils and,

6. construction of impervious features on soils with low infiltration rates.

Maintaining the Predevelopment Time of Concentration Tc

The LID hydrologic evaluation requires that the post development Tc be close to the predevelopment Tc. Minimizing

the change in pre and post Tc will help maintain the same frequency of runoff discharges, assuming there is uniform

distributed micro-scale retention and detention of LID practices. The following are some of the site planning techniques

can be used to maintain the existing Tc:

1. maintain predevelopment flow path length by dispersing and redirecting flows using open swales and vegetated

drainage patterns,

2. increase surface roughness (e.g., preserving woodlands, vegetated swales),

3. detain flows (e.g., open swales, rain gardens, rain barrels etc.),

4. minimize disturbances (minimizing soil compaction and changes to existing vegetation /drainage patterns),

5. flatten grades in impacted areas,

6. disconnect impervious areas (e.g., eliminating curb/gutter and redirecting down spouts) and,

7. connect pervious areas to vegetated areas (e.g., reforestation, afforestation).

The combined use of all these techniques results in cumulative impacts that modify runoff characteristics to effectively

shift the post development peak runoff time and frequencies to that of the predevelopment condition, and lower the peak

runoff rate.

Maintaining the Redevelopment Curve Number and Runoff Volume

Once the post development Tc is maintained at the predevelopment conditions and the impact of CN is minimized,

any additional reductions in runoff volume must be accomplished through distributed micro-scale on-site stormwater

management techniques. The goal is to select the appropriate combination of management techniques that simulate the

hydrologic functions of the predevelopment condition to maintain the existing CN and corresponding runoff volume. The

target design volume is equal to the initial abstraction of rainfall that would have occurred in the predevelopment condition.

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LID site designs maximize the use of small retention practices distributed throughout the site at the source to provide the

required volume storage. The required storage volume will be reduced when the change in the pre and post CN is

minimized.

Retention storage allows for a reduction in the post development volume and the peak runoff rate. The increased

storage and infiltration capacity of retention LID BMP’s allow the predevelopment volume to be maintained. The most

appropriate retention BMP’s include:

1. bioretention cells (rain gardens),

2. infiltration trenches,

3. water use storage (rain barrels and gray water uses) and,

4. roof top storage.

Other possible retention BMP’s include retention ponds, cisterns and irrigation ponds but it may be difficult to distribute

these types of controls throughout a development site.

As retention storage volume is increased there is a corresponding decrease in the peak runoff rate, in addition to

runoff volume reduction. If a sufficient amount of runoff is stored, the peak runoff rate may be reduced to a level at or

below the predevelopment runoff rate. This storage may be all that is necessary to control the peak runoff rate when there

is a small change in CN. However, when there is a large change in CN, it may be less practical to achieve flow control

using volume control only.

Potential Requirement for Additional Detention Storage

In cases where very large changes in CN cannot be avoided, retention storage practices alone may be either

insufficient to maintain the predevelopment runoff volume or peakdischarge rates or require too much space to represent

a viable solution. In these cases, additional detention storage will be needed to maintain the predevelopment peak runoff

rates. A number of traditional detention storage techniques are available that can be integrated into the site planning and

design process for a LID site. These techniques include:

1. swales with check dams, restricted drainage pipes, and inlet/entrance controls,

2. wide, low gradient swales,

3. rain barrels/cisterns,

4. rooftop storage and

5. shallow parking lot/road storage.

Determination of Design Storm Event

The hydrologic approach of LID is to retain the same amount of rainfall within the development site as was retained

prior to any development (e.g., woods or meadow in good condition) and then release runoff as the woods or meadow

would have. By doing so, it is possible to mimic, to the greatest extent practical, the predevelopment hydrologic regime

to maximize protection of receiving waters, aquatic ecosystems and ground water recharge. This approach allows the

determination of a design storm volume that is tailored to the unique soils, vegetation and topographic characteristics of

the watershed. This approach is particularly important in watersheds that are critical for ground water recharge to protect

stream/wetland base flow and ground or surface water supplies.

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LID BMP’s

Site design techniques and BMP’s can be organized into three major categories as follows; 1) runoff prevention

measures designed to minimize impacts and changes in predevelopment CN and Tc, 2) retention facilities that store runoff

for infiltration, exfiltration or evaporation and 3) detention facilities that temporarily store runoff and release through a

measured outlet. Table 1, below, lists some of a wide array of LID BMP’s and their primary functions. Placing these BMP’s

in series and uniformly dispersing them throughout the site provides the maximum benefits for hydrologic controls.

Table 1. Examples of LID BMP’s and Primary Functions

BMP

Bioretention

Infiltration Trench

Dry Wells

Roof Top Storage

Vegetative Filter Strips

Rain Barrels

Swale and Small Culverts

Swales

Infiltration Swale

Reduce Imperviousness

Strategic Clearing / Grading

Engineered Landscape

Eliminate Curb and Gutter

Vegetative Buffers

Runoff Detention

Prevention

X

X

X

X

X

X

X

X

X

X

X

X

Retention Conveyance Water

Quality

X X

X X

X

X X

X X

X

X

X

X X

X

X

X

X

X

Water Quality

LID maximizes the use of the developed landscape to treat stormwater runoff. Not only can the landscape be used

to store, infiltrate and detain runoff, the unique physical, chemical and biological pollutant removal/

transformation/immobilization/detoxification capabilities of the soil, soil microbes and plants can be used to remove

pollutants from runoff. For example, bioretention basins or rain gardens are designed to use the upland soil/microbe/plant

complex to remove pollutants from runoff. Rain gardens which look and function like any other garden except they treat

runoff are designed with a layer of 2-3 inches of mulch, 2-3 feet of planting soil and vegetation (trees shrubs and flowers).

Figure 1 shows a parking lot landscape island rain garden (bioretention practice) that uses a high rate filter media with

plants to filter and treat 90% of the annual volume of runoff from the parking lot.

Figure 1. Parking Lot Rain Garden.

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Studies conducted by the University of Maryland have shown rain gardens to be very effective in removing pollutants.

The percent pollutant removal of various contaminants is shown below in Table 2. The results shown represent the

average removal rates under a wide variety of flow rates and pollutant concentrations.

Table 2. Percent Pollutant Removal by Rain Gardens

cu Pb Zn P TKN NH4+ NO3 TN*

% % % % % % % %

93 99 99 81 68 79 23 43

l Removal varied as a function of depth in the soil. Percent removal shown is at a depth of approximately 3 feet.

Testing Conducted by the University of Maryland, Department of Engineering

The variety of physical, chemical and biological pollutant removal mechanisms available in the complex rain garden

system is staggering. A description or explanation in any detail of these mechanisms is beyond the scope of this paper.

A more detailed description can be found in the 1998 “Optimization of Bioretention Design” study conducted by the

University of Maryland. Mulch has been found to be very effective in removing heavy metals through organic complexing

with the hydroxyl and carboxyl sites on the organic molecules. Soil bacteria can metabolize (use as a carbon energy

source) oil, grease and gasoline into CO2 and water in the presence of adequate nutrients and oxygen. Soil bacteria have

been used for years for the remediation of contaminated soils. Plants are known to uptake, transpire, accumulate and

detoxify heavy metals and many other toxic compounds. The physiologic and metabolic processes of plants are used to

clean contaminated soils through phytoremediation. A goal of LID is to maximize the use of upland landscape with its soil/

microbes/ plant complex to treat runoff. Using upland systems to trap and remove pollutants allows one to more easily

control the fate of contaminants and prevent them from entering the water column where they are almost impossible to

contain and remove.

Public Outreach and Pollution Prevention

Pollution prevention and maintenance of on-lot LID BMP’s are two key elements in a comprehensive approach.

Effective pollution prevention measures can reduce the introduction of pollutants to the environment and extend the life

of LID treatment BMP’s. Public education is essential to successful pollution prevention and BMP maintenance. Not only

will effective public education complement and enhance BMP effectiveness, it can also be used as a marketing tool to

attract environmentally conscious buyers, promote citizen stewardship, awareness and participation in environmental

protection programs and help to build a greater sense of community based on common environmental objectives and the

unique character of LID designs.

costs

LID case studies and pilot programs show that at least a 25% reduction in both site development and maintenance

costs can be achieved by reducing grading and the use of pipes, ponds, curbs and paving. In one subdivision called

Somerset which used the rain garden LID technique for water quality controls, the developer saved $4,500 per lot or a

total of $900,000 by eliminating the need for curbs, ponds and drainage structures. Maintenance costs are also reduced

in scale and magnitude by using the small LID practices. LID site designs require only routine landscape care and

maintenance of the vegetation, This eliminates the high costs of pond maintenance associated with dam repairs and

dredging.

Road Blocks to LID

In the development and acceptance of the LID site planning approach, a number of roadblocks had to be overcome.

Regulating agencies, the development community and the public all had concerns about the use of new technology. The

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LID design manual represents the culmination of four years of work to address all of these concerns and issues. Some

of the major components of the LID approach, which addressed the many concerns, include:

1. develop an hydrologic analytical methodology to demonstrates the equivalence of LID to conventional approaches,

2. develop new road standards which allow for narrow roads, open drainage and cluster techniques,

3. streamline the review process for innovative LID designs which allow easy modification of site, subdivision, road

and stormwater requirements,

4. develop a public education process which informs property owners on how to prevent pollution and maintain on

lot BMP,

5. develop legal and educational mechanisms to ensure BMP’s are maintained,

6. demonstrate the marketability of green development,

7. demonstrate the cost benefits of the LID approach,

8. provide training for regulators, consultants, public and political leaders and,

9. conduct research to demonstrate the effectiveness of bioretention BMP’s.

Summary

LID is a viable economically sustainable alternative approach to stormwater management and the protection of natural

resources. LID provides tangible incentives to a developer to save natural areas and reduce stormwater and roadway

infrastructure costs. LID can achieve greater natural conservation by using conservation as a stormwater BMP to reduce

the change in CN. As more natural areas are saved, less runoff is generated and stormwater management costs are

reduced. This allows multiple use and benefits (environmental and economical) of the resource.

Additionally, developers have incentives to reduce infrastructure costs by reducing impervious areas, and eliminating

curbs/gutters and stormwater ponds to achieve LID stormwater controls. Reduction of the infrastructure also reduces

infrastructure maintenance burdens making LID designs more economically sustainable. Superior protection of aquatic

and riparian ecosystems can be achieved since a LID developed watershed functions in a hydrologically similar manner

as the predevelopment conditions. Recreating the predevelopment hydrological regime is a better way to protect the

receiving waters than the conventional end-of-pipe mitigation approaches.

LID promotes public awareness, education and participation in environmental protection. As every property owner’s

landscape functions as part of the watershed, they must be educated on the benefits and the need for maintenance of

the landscape and pollution prevention. LID developments can be designed in a very environmentally sensitive manner

to protect streams, wetlands, forest habitat, save energy, etc. The unique character of a LID green development can

create a greater sense of community pride based on environmental stewardship.

References

Prince George’s County, Maryland. Department of Environmental Resources. Low-Impact Development Design Manual.

(PGC, 1997)

Prince George’s County, Maryland. Department of Environmental Resources. Low-Impact Development Guidance

Manual. (PGC, 1997).

Prince George’s County, Maryland. Design Manual for use of Bioretention in stormwater Management. (PGC, 1993).

166
Prince George’s County, Maryland. Optimization of Bioretention Design for WaterQualityand HydrologicCharacteristics.

(Davis, et al. 1998).

167
A National Menu of BMPs for the Phase II NPDES Storm Water Program

James H. Collins

Tetra Tech, Incorporated

Fairfax, VA

John A. Kosco, P.E.

USEPA/Off ice of Wastewater Management

Washington, DC

Introduction

Implementation of the Phase II NPDES Storm Water Program, which is presently “proposed,” will be enhanced by

the development of several tools used to help reduce discharges of pollutants from regulated small construction activities

and from regulated small municipal separate storm sewer systems (MS4s). One of the tools being developed by EPA

is a national menu of best management practices (BMPs), from which regulated Phase II municipalities can select as they

develop their stormwater management programs.’ The purpose of the national menu of BMPs is to provide a list of

options available to regulated Phase II municipalities as they develop a stormwater programs. The national menu of

BMPs may be adopted or modified by each NPDES permitting authority, or the permitting authority may develop its own

menu of BMPs for use by the Phase II municipalities under its jurisdiction. This paper describes the process of developing

the national menu of BMPs and measurable goals for each of the six minimum measures required to be in the stormwater

management programs.

Process of Development

The process used in developing the menu was to first list appropriate BMPs for each minimum control measure, with

subcategories under certain control measures.’ Then, a basicformat for presenting the information about each BMP was

established. Information being provided for each BMP in the menu consists of BMP name, description, an illustration,

applicability and design considerations, limitations, operation and maintenance, effectiveness, cost, and references. The

menu is being prepared by EPA, with support from Tetra Tech, Incorporated, and the Center for Watershed Protection.

A peer involvement/peer review group has been selected and will provide review and input to the process of developing

the menu over the course of the next year. The menu is currently being reviewed and developed as a traditional hard

copy document. Following development, there are plans to make the menu available as an interactive Web-based tool.

The menu of BMPs is scheduled to be released by October, 2000.

Descriptions of Six Minimum Control Measures, with Lists of BMPs

I) Public Education and Outreach

This measure in the proposed rule calls for the creation of a public education program to inform citizens about the

impacts that stormwater runoff can have on water quality. It includes the preparation and distribution of educational

materials to the community, describing these impacts and steps that can be taken to reduce pollution from discharges

of stormwater. Examples of such steps include proper septic system maintenance, limitations on use and runoff of

household and garden chemicals, proper disposal of used motor oil or household hazardous wastes, and involvement

in local stream restoration activities. The following BMPs have been identified (in the Draft Rule) under four major

subcategory groups in the menu for the Public Education and Outreach minimum measure:

Public outreach/education for homeowners

l Lawn and garden activities, including proper pesticide use and disposal practices

168
l Water conservation practices

l Proper disposal of used materials or household hazardous wastes

l Pet waste management

Targeting public outreach/education

l Education/outreach for commercial activities (parking lots, gas stations, etc.)

l Tailoring outreach programs to communities, including minority and disadvantaged, as well as children

l Classroom education on stormwater

l Distributing stormwater educational materials (how, to whom)

Public Outreach Programs for New Development

l Low-impact development (includes buyer awareness, legal documents, and settlement documents)

Pollution Prevention Programs for Existing Development

l Educational display, pamphlet, booklet, utility stuffer

l Using the media (includes newspaper, magazine, radio, television, public service announcements, and Internet

messages)

l Promotional giveaway

2) Public Participa tionllnvolvemen t

This measure in the proposed rule includes compliance with state and local public notice requirements, but goes

beyond that to encourage municipalities to seek public involvement in the development and review of their stormwater

programs. Opportunities for members of the public to participate in the development of their municipality’s stormwater

management program may include serving as citizen representatives on a local stormwater management panel, attending

public hearings, working as citizen volunteers to educate others about the program, assisting in program coordination with

other pre-existing programs, or participating in volunteer monitoring efforts. The following BMPs have been identified

under two major subcategory groups of practices in the menu for the Public Participation/Involvement minimum measure:

Activities/Public Participation

l Storm drain stenciling

l Stream cleanup

l Volunteer monitoring

l Reforestation program

l Wetland plantings

l Adopt-A-Stream program

Involvement/Public Opinion

l Watershed organization

169
l Stakeholder meetings (includes local stormwater management ponds)

l Attitude surveys

l Community hotlines

3) l/licit Discharge Detection and Elimination

This measure envisions the creation of an illicit discharge detection and elimination program. Specific program

elements include developing a demonstrated knowledge base of the MS4, using maps or other documents to identify

major outfalls and pipe networks on a topographic basis; developing a plan to address illicit discharges into the MS4,

including appropriate enforcement procedures to the extent allowable by law; and developing a process for informing the

public about the hazards associated with illicit discharges and the improper disposal of waste. For example, recycling

programs and other public outreach activities could be developed to address sources of illicit discharges, including used

motor oil, antifreeze, pesticides, herbicides, and fertilizers. The following BMPs have been identified for the menu for the

Illicit Discharge Detection and Elimination minimum measure:

l Failing septic systems

l Industrial connections

9 Recreational sewage

. Sanitary sewer overflows

l Identifying illicit connections

l Wastewater connections to the storm drain system

4) Construction Runoff Control

This measure provides for the enforcement of a program to reduce pollutants in storm water runoff from construction

activities resulting in the disturbance of one acre to five acres of land. The program would apply to the individuals

responsible for activities at construction sites and should include an ordinance to control sediment and erosion; a

mechanism to ensure control of other wastes at construction sites, such as discarded building materials, concrete truck

washout, and sanitary waste that could impact water quality; requirements for the implementation of appropriate BMPs,

such as silt fences, temporary detention ponds and hay bales; provisions for preconstruction review of site management

plans; procedures for receipt and consideration of comments and other information provided by the public; regular

inspections during construction; and penalties to ensure compliance. The following BMPs have been identified under 11

major subcategory groups of practices in the menu for the Construction Runoff Control minimum measure:

Minimize Clearing

l Land grading

l Permanent diversion

l Preservation of natural vegetation (includes tree preservation and protection)

Stabilize Exposed Soils

l Chemical stabilization

l Mulching

170
l Permanent seeding

l Sodding

l Soil roughening

Protect Steep Slopes

l Geotextiles

l Gradient terraces

l Soil retention (includes slope stabilization, retaining wall, reinforcement)

l Temporary slope drain (a.k.a. - pipe slope drain)

l Temporary storm drain diversion

Stabilize Drainage Ways

l Check dam (a.k.a. grade stabilization structure)

l Filter berm

l Grass-lined channel

l Riprap

Protect Waterways

l Temporary diversion

l Temporary stream crossing (bridge, culvert)

l Vegetated buffer

Phase Construction

l Construction sequencing

. Dust control

Install Perimeter Controls

l Temporary diversion dikes, earth dikes, and interceptor dikes (includes temporary fill diversions)

l Sand fence and wind fences

l Silt fence

l Brush barriers

Install Sediment Trapping Devices

l Sediment basin/rock dam

l Sediment filters and sediment chambers

171
l Sediment traps

Inlet Protection

l Stabilized construction entrances

l Storm drain inlet protection (includes block and gravel, excavated drop, fabric drop, and sod drop inlet protection)

Education and Awareness

l Contractor certification and inspector training

l BMP inspection and maintenance

5) Post-Construction Runoff Control

This measure uses post-construction controls as part of a program to address stormwater runoff from new

development and redevelopment projects using appropriate structural and non-structural BMPs. Non-structural BMPs

are preventive actions using management and source controls, such as policies and ordinances that result in protection

of natural resources and prevention of runoff. Non-structural BMPs might include requirements that encourage growth

in identified areas while protecting sensitive areas such as wetlands and riparian zones, minimizing impervious surfaces,

maintaining open space, and minimizing clearing, grading, or other disturbance of soils and vegetation. Some of the

typical structural BMPs include storage practices (wet ponds, extended-detention dry ponds, or other storage facilities

with outlets); infiltration practices (infiltration basins, infiltration trenches, and porous pavement); and filtration practices

(grassed swales, sand filters, and vegetated filter strips). This measure should also ensure effective and reliable

performance by providing for the long-term operation and maintenance of the selected BMPs. The following BMPs have

been identified under eight major subcategory groups of practices for the Post-Construction Runoff Control minimum

measure:

Ponds

l Extended detention dry basin or pond (with or without permanent pools or shallow marshes near the outlet),

includes tank storage

9 Wet pond

Infiltration Practices

l Infiltration basin (a.k.a. - recharge basin)

l Infiltration trench (a.k.a. - infiltration galley)

l Porous pavement

Filtration Practices

. Bioretention

l Filters, including organic media filter (peat sand or compost-type), sand filter, multichamber treatment train (MClT)

system, and inlet filtration systems

Vege ta five Practices

l Constructed wetland, shallow marsh

l Grassed swale

172
l Vegetative filter strip

Runoff Pretreatment Practices

l Catch basin

l In-line storage, includes flow regulator information

l Manufactured systems for water quality inlets

Experimental Practices

l Alum injection system

On-lot Treatment

l On-lot treatment includes information on dry wells, roof downspout systems, rain barrels, exfiltration storage

systems, french drains, and dutch drains

Better Site Design

l Conservation easements

l Infrastructure planning

l Buffer zones/setbacks

l Open space development

l Narrow streets

l Curb elimination

l Green parking lot

. Alternative turn-around

l Urban forestry

l Alternative pavers

6) Pollution Prevention/Good Housekeeping

This measure in the proposed rule envisions the creation of an operation and maintenance/training program to prevent

or reduce pollutant runoff from municipal operations. The program should include training for municipal staff to address

prevention measures in government operations, such as parkand open space maintenance, fleet maintenance, planning,

building oversight and stormwater collection system maintenance. Other possible pollution prevention activities that might

be relevant include controls for reducing or eliminating the discharge of pollutants from streets, roads, highways, municipal

parking lots, maintenance and storage yards, and waste transfer stations; programs to promote recycling and pesticide

use information; procedures for proper disposal of waste removed from municipal systems and public areas (such as

streets) including dredge spoil, accumulated sediments, floatables, and other debris; and new flood management projects

to assess the impacts on water quality and examine exiting projects to determine if they need additional water quality

protection devices or practices. The following BMPs have been identified under two major subcategory groups of

practices in the menu for the Pollution Prevention/Good Housekeeping minimum measure:

173
Source con fro/s

l Animal waste collection

l Automobile maintenance

l Car washing

l Illegal dumping control

l Landscaping and lawn care

l Pest control

l Parking lot and street cleaning

l Roadway and bridge maintenance

l Septic system controls

Materials Management

l Alternative products

l Hazardous materials storage

l Household hazardous waste collection

l Road salt application and storage

l Spill response and prevention

l Used oil recycling

Conclusion

As part of the Stormwater Phase II Tool Box, the Menu of BMPs should help municipalities develop, implement, and

enforce the Phase II program. The menu will be available in time for regulated municipalities to use in complying with

stormwater management program requirements under Phase 2 permits and might also benefit other jurisdictions and

individuals.

References

USEPA, 1999. Storm Water Phase II Fact Sheet Series 1-4. April 1999. EPA 833-F-99-001 through 015.

USEPA, 1998. 40 CFR Parts 122 and 123; National Pollutant Discharge Elimination System-Proposed Regulations for

Revision of the Water Pollution Control Program Addressing Storm Water Discharges; Proposed Rule. Friday January

9,1998. 63 FR 1536.

174
Determining Urban Stormwater BMP Effectiveness

Eric Strecker

URS Greiner Woodward Clyde

Portland, OR

Marcus M. Quigley

URS Greiner Woodward Clyde

Boston, MA

Ben R. Urbonas

Urban Drainage and Flood Control District

Denver, CO

Abstract

The overall purpose this US EPA funded cooperative research program with the American Society of Civil Engineers

(ASCE) is to develop a more useful set of data on the effectiveness of individual best management practices (BMPs) used

to reduce pollutant discharges from urban development. BMP performance data gathered at a particular site should not

only be useful for that site, but also be useful for comparing studies of similar and different types of BMPs in other

locations. Almost all BMP effectiveness studies in the past have provided very limited data that is useful for comparing

BMP design and selection among individual BMP types (e.g. sand filters). This paper overviews some of the problems

of past BMP effectiveness studies from the perspective of comparability between studies. It suggests some of the ways

that data should be collected to make it more useful for assessing factors (such as settling characteristics of inflow solids

and physical features of the BMP) that might have led to the performance levels achieved. It briefly presents the

database that has been developed by this project, which not only serves as a tool for storing data from existing studies,

but as a tool for entering and storing data collected from future studies. Discussed are considerations that affect data

transferability, such as effectiveness estimations, statistical testing, etc. It overviews the efforts to establish and analyze

the data base for existing studies and overviews proposed analyses for the future, when more studies that have followed

the protocols are available. The database has specifically pointed out the need for additional BMP performance studies,

as the current data is very sparse in terms of studies that have recorded enough information to be useful in assessing

BMP type performance.

Introduction

Many studies have assessed the ability of stormwater treatment BMPs (e.g., wet ponds, grass swales, stormwater

wetlands, sand filters, dry detention, etc.) to reduce pollutant concentrations and loadings in stormwater. However, in

reviewing and summarizing the information gathered from these individual BMP evaluations, it is apparent that

inconsistent study methods and reporting make wider-scale assessments difficult, if not impossible. For example,

individual studies often included the analysis of different constituents and utilized different methods for data collection and

analysis, as well as varying degrees of information on BMP design and inflow characteristics. Just the differences in

monitoring strategies and data evaluation alone contribute significantly to the range of BMP “effectiveness”that has been

reported. These differences make combining these individual studies almost impossible to assess what design factors

may have contributed to the variation in performance (Strecker et al., 1992). Urbonas (1994 and 1995) and Strecker

(1994) summarized information that should be recorded regarding the physical, climatic, and geological parameters that

likely affect the performance of a BMP and considerations regarding sampling and analysis methods.

Efficiency, Effectivness, and Performance

In order to better clarify the terminology used to describe the level of treatment achieved and how well a device,

system, or practice meets its goals, definitions of some terms often used loosely in the literature are provided here. These

terms help to better specify the scope of monitoring studies and related analyses:

175
l Best Management Practice (BMP) -A device, practice, or method for removing, reducing, retarding, or preventing

targeted stormwater runoff constituents, pollutants, and contaminants from reaching receiving waters

l BMP System - A BMP system includes the BMP and any related bypass or overflow. For example, the efficiency

(see below) can be determined for an offline retention (Wet) Pond either by itself (as a BMP) or for the BMP system

(BMP including bypass)

l Performance - measure of how well a BMP meets its goals for stormwater that is treated by the BMP

l Effectiveness - measure of how well a BMP system meets its goals in relation to all stormwater flows

l Efficiency - measure of how well a BMP or BMP system removes pollutants

The ASCE project team is working with available data to determine efficiency of BMPs and BMP systems. In

addition, effectiveness and performance are being evaluated, acknowledging the limitations of existing information about

the goals of specific BMP projects. Quantification of efficiency only evaluates a portion of the overall performance or

effectiveness of a BMP or BMP system. Calculation of the efficiency helps to determine additional measures of

performance and effectiveness, for example the ability of a BMP to meet any regulatory goals. A list of typical goals and

the current ability of the ASCE/EPA project to help evaluate them is shown in Table 1.

Problem: BMP Performance Study Inconsistencies

Studies of BMP effectiveness have utilized significantly different:

l sample collection techniques (e.g., from sample collection types--grab, composite, etc., flow measurement

techniques, to how the sample was cornposited, etc.);

l water quality constituents, including: chemical species, methods (detection limits), form (e.g., dissolved vs. total,

vs. total recoverable, etc.), and treatment potential;

l data reporting on tributary watershed and BMP design characteristics ( e.g., tributary area or watershed attributes

such as percent impervious, land use categories, rainfall statistics, etc.);

l effectiveness estimation techniques (there are at least four common techniques that have been utilized to assess

effectiveness that can cause significant differences in pollutant removal reporting, with the same set of data), and

potential alternatives to reporting just concentration/loading reductions; and

l statistical validation of results (typical lack of statistical tests to determine if the reported removal efficiency can in

fact be shown to be statistically different than zero).

Monitoring strategies that could be employed to monitor BMP effectiveness include:

l New BMP installation with new development- input/output (e.g., monitor new detention pond of newly developed

watershed and evaluate inflow concentrations/loads vs. outflows) or conduct a “control” watershed comparison

l Retrofit of existing or new single BMP within existing watershed--input/output, and/or, before/after (e.g., retrofit of

an existing flood control basin for water quality)

l Watershed-wide new structural or non-structural--“control” watershed comparison (e.g., new BMP catch basins

in developing area)

l Watershed-wide structural retrofit or application of non-structural - before/after, and/or, “control” watershed

comparison (e.g., catch basin retrofit on watershed scale)

Input/output monitoring is the typical approach utilized. However, control watersheds and before/after approaches

have also been employed. All of the other potential factors that could be contributing to differences in performance must

identified and accounted. On the other hand, it is beneficial to be able to show that a watershed-wide difference is or is

176
Table 1. Goals of BMP Projects and the Ability of the National Stormwater BMP Database to Provide Information Useful for Determining

Performance and Effectiveness

Goals of BMP Projects

Category

Ability to Evaluate

Performance and Effective

Hydraulics *Improve flow characteristics upstream and/or downstream of BMP

Hydrology

Water Quality

(Efficiency)

Toxicity

Regulatory

Implementation Feasibility

cost

‘ImfAer&ef@earance of site

Maintenance

l Uangg* functionality

Resources

Safety, Risk and Liability

Public Perception

‘Flood mitigation, improve runoff characteristics (peak shaving)

*Reduce downstream pollutant loads and concentrations of pollutants

‘Improve/minimize downstream temperature impact

*Removal of litter and debris

*Reduce acute toxicity of runoff

*Reduce chronic toxicity of runoff

*Compliance with NPDES permit

*Meet local, state, or federal water quality criteria

*For non-structural BMPs, ability to function within management and oversight

structure

*Capital, operation, and maintenance costs

*Operate within maintenance, and repair schedule and requirements

*Ability of system to be retrofit, modified or expanded

‘Improve downstream aquatic environment/erosion control

*Improve wildlife habitat

*Multiple use functionality

*Function without significant risk or liability

*Ability to function with minimal environmental risk downstream

‘Information is available to clarify public understanding of runoff quality, quantity

and impacts on receiving waters

J’

J’

J

J

J can be evaluated using the ASCE/EPA Database as information source

J’ will be able to be evaluated using the database as primary source of information after enough studies have been submitted

J* can be evaluated using the database the primary source of information combined with a secondary source of comparative data

not being detected with BMP implementation. These differences in monitoring approach certainly effect the ability to

compare studies.

Any of the above topics would require an in-depth discussion beyond the scope of this paper. Therefore, this paper

will present only a brief overview of each and some potential solutions for improving how data is collected. The ASCE

project team has developed a set of protocols and a database on BMP performance studies with the purpose of improving

the consistency of BMP monitoring information. The project includes:

l Developing protocols for BMP monitoring and reporting

l Developing a database on BMP performance studies

l Conducting an evaluation of existing information to assist EPA in providing guidance to the regulated community

177
The database specifies a chosen set of reporting information, but does not guide users on how to develop such

information. For example, it does not specify in detail what a flow-weighted composite sample is and how it should be

collected. The next step beyond the EPA protocols and database effort should be a guidance document on monitoring

data collection strategies and techniques to improve their consistency and ultimate transferability. A few of the issues

related to proper guidance are discussed in the next two sections. It should be recognized that, with the development of

the database and the protocols, it will be a number of years (5 to 10) before a significant number of new studies on BMPs

are conducted utilizing the protocols. Therefore, a rigorous evaluation of BMP selection and design factors will need to

take place in the long-term future.

Recommended Parameters for Assessing BMP Performance

In developing a method for quantifying BMP performance, it is helpful to look at the objectives of previous studies

seeking such a goal. BMP performance studies usually are conducted to obtain information regarding one or more of the

following objectives:

l What degree of pollution control does the BMP provide under typical operating conditions?

l How does performance vary from pollutant to pollutant?

l How does performance vary with various input concentrations?

l How does performance vary with large or small storm events?

l How does performance vary with rainfall intensity?

l How do design variables affect performance?

l How does performance vary with different operational and/or maintenance approaches?

. Does performance improve, decay, or remain the stable over time?

l How does the BMP’s performance compare relative to other BMPs?

l Does the BMP reduce toxicity to acceptable levels?

l Does the BMP cause an improvement in downstream biotic communities?

l Does the BMP have potential downstream negative impacts?

The monitoring efforts implemented most typically seek to answer a subset of the above questions. This often leaves

larger questions about the performance of the BMP, and the relationship between design and performance, unanswered.

Standardization of BMP data collection and evaluation methods (i.e., guidance and the ASCE/EPA database) allows this

broader set of questions to be examined.

There has been a very wide variety of pollutants analyzed in BMP and characterization studies. The protocols

established under the EPA-funded cooperative research program recommend a standard set of constituents for BMP

testing programs. Table 2 presents the recommended constituents developed from the review of previous studies with

an understanding of costs and likelihood of providing meaningful results. A discussion of how these constituents were

selected and a detailed description of each can be found in Strecker (1994).

There are some practical and technical considerations regarding data reporting which would facilitate data

usefulness, including consistent formatting of data, the clear indication of QA/QC results, standard comparisons to water

quality criteria, reporting of tributary watershed characteristics, and BMP design information. The last two items are

considered critical for evaluation of what contributed to BMP effectiveness in one location over another.

Data Reporting. It is recommended that all constituent concentration data be reported as event mean concentrations

(EMCs). These statistics should be based on use of the lognormal distribution. The NURP and FHWA studies (EPA,

178
Table 2. Recommended Standard Analytical Tests for Urban Stormwater BMP Assessment

Lab Analysis

Conventional

TSS

TDS

TOC

COD

Total Hardness

EPA Method Detection

Number Limit (mg/l)

EPA 160.2 1

EPA 160.1 1

EPA 415.1 3

EPA 410.4 1

SM 314-A 1

Nutrients

(NH3 - N) SM 417-AD 0.1

Total phosphorus (as P) SM 424-CE 0.005

Ortho-phosphate (as P) SM 424-E 0.05

Nitrate + nitrite (NO, + NO’ - N) EPA 353.1 or .2 0.05

Total Metals

Cd (cadmium)

Pb (lead)

Cu (copper)

Zn (zinc)

EPA 7131 0.0002

EPA 7421 0.0003

EPA 6010 0.001

EPA 6010 0.001

Dissolved Metals

Cd (cadmium)

Pb (lead

Cu (copper)

Zn (zinc)

EPA 7131 0.0002

EPA 7421 0.0003

EPA 6010 0.001

EPA 6010 0.001

1983a; Driscoll et al., 1990) identified that the lognormal distribution is suitable for characterizing EMC distributions. The

high degree of variability is why proper statistical techniques should be employed to evaluate whether a measured

difference between BMP before/after or input/output is significant. The recommended inclusion of outlet data as a part

of any paper or report will allow comparisons of typical outlet concentrations and may allow the determination of the lowest

or average expected concentration from a particular type of BMP. For example, it may be that wet ponds may only be

able to treat to some minimum concentration range at the outlet and the “effectiveness” is greatly impacted by the inlet

concentrations.

Qua/ityAssurance/QualityContro/ (CWQC). All monitoring studies should include a QNQC program. The details and

results of the QA/QC program should be reported in monitoring study reports and summarized in papers. It is especially

important to discuss when data are characterized as estimates due to QA/QC results and when detection limits were

affected. Too often this information is not included.

Comparisons to Water Quality Criteria. A method to gage effectiveness could be to monitor how the BMP affects

the number of times (frequency) that EPA water quality criteria are exceeded in both the inflow and the outflow, to assess

how the BMP reduces (or does not reduce) the frequency of potentially toxic events. For heavy metals analyses, it is

recommended that hardness be collected for all storms monitored and that comparisons to criteria be made utilizing the

dissolved fraction with the computed aquatic criteria as modified by EPA (1993b).

Watershed and BMP Design Parameters. Table 3 presents a summary of these parameters. These parameters

(more detailed parameter lists are available on ASCE’s Web page at http://www.asce.org/peta/tech/ nsbd01 .html) have

been selected with the purpose of being able to utilize this information to evaluate what BMP design attributes and

tributary watershed characteristics can be linked to BMP effectiveness information.

The primary goals of the ASCE/EPA database development process were to facilitate efficient data entry, provide

useful queries of stored data, and output information in a comprehensive and applicable manner through a user-friendly

interface. The database was written in Microsoft@ Access incorporating Access relational database engine and features

and the Visual Basic@for Applications programming language for customization of the functional aspects of the front end.

Distribution will take place initially as an Access run-time version on CD-ROM, but will be available in the nearfuture over

the Internet.

179
Table 3. Parameters to Report with Water Quality Data for Various BMPs

>arameter

Type Parameter

Retention (Wet)

Pond

Extended Wetland

Detention (Dry) Pond

Basin Basin

Grass Swale/ Sand/Leaf

Wetland Channel Compost Filter

Oil & Sand Trap/

Hydro-dynamic

Device

Infiltration and

Pert..

ibutary Tributary watershed area, average slope, . . . . . . .

atershed average runoff coefficient, length, soil types,

Jegetation types

Total tributary watershed impervious percentage . . . . .

. .

and percent hydraulically connected

Details about gutter, swer, swale, ditches,

zrarking, roads in watershed . . . . .

-and use types (res., comm., ind., open) and . .

acreage . . . . .

. .

eneral Iate and start/stop times for monitored storms . . . . . . .

ydrology %noff volumes for monitored storms

‘eak 1 -hr intensity .

. . . . . .

3esign storm/flood recurrence intervals and .

. . . . . .

nagnitude .

. . . . . .

=eak flow rate, depth, and Manning’s roughness

:oefficient for the 2-year storm .

3epth to seasonal high

JroundwaterAmpermeable layer . . .

3aturated hydraulic conductivity, infiltration rate,

soil group . .

4verage annual values for number of storms,

>recipitation, snowfall, min./max. Temp., from .

. . .

. . .

appropriate weather station

later Ukalinity, hardness and pH for each monitored l . . . . . .

storm

iNater temperature . . . . . . .

3ediment settling velocity distribution, when l . . . . . .

nvailable

=acility on- or off-line? . . . . . . .

3ypassed flows during events . . . . . . .

180
r

‘et Pool dolume of permanent pool

..

..

-ength of permanent pool

..

..

‘ermanent pool surface area

.

.

.

.

Atoral zone surface area

.

3olar radiation, days of sunshine, wind speed,

. . .

.

.

Ian evaporation, from appropriate weather

station

eneral Type and frequency of maintenance

.

.

..

.

..

rcility Types and location of monitoring instruments

...

...

.

nlet and outlet dimensions, details, and number

...

..

.

.

Wedia or granular material depth, type, storage

/olume, and porosity

.

.

etention 3etention (or surcharge) and flood control

.

.

.

.

*

.

olume ilolumes

3etention basin’s surface area and length

..

.

..

.

3rimful and half-brimful emptying time

.

.

.

.

.

.

3ottom stage/infiltrating surface area and type

.

..

retreatment -orebay volume, surface area

.

.

.

.

.

.

lant qelationship to other BMP’s upstream

..

..

..

.

retland

lant

Netlandlswale type, surface area, and length,

side slope lbottom width for swales and

channels)

..

Percent of wetland surface between O-12”, 12-

?4”, and 24-48”

.l

‘Iant species and age of facility

.

.

.

.

181
182

Estimation of BMP Pollutant Removal Effectiveness and Effectiveness

BMP pollutant removal effectiveness estimations are not straightforward and a wide variety of methods have been

employed. Martin and Smoot (1986) discussed three types of methods to compute efficiencies, including an efficiency

ratio, sum of loads, and regression of loads. Many researchers have utilized an efficiency measure based upon storm

pollutant loads into and out of the BMP on a storm-by-storm basis. This weights the effectiveness considering that all

storms are “equal” in computing the average removal. However, it is readily apparent that all storm volumes and their

associated concentrations are not equal. 

One factor that complicates the estimation of the effectiveness is that for wet ponds and wetlands, (and other BMPs

where there is a permanent pool), comparing effectiveness on a storm-by-storm basis neglects the fact that the outflow for

a particular event being measured may have little or no relationship to the inflow for that same event. Based upon a

national characterization of rainfall (Driscoll, et. al., 1989), if a basin were sized to have a permanent pool equal to the

average storm, about 60 to 70% of the storms would be less than this volume. Therefore, in many cases, flows leaving

may have little or no relationship to flows entering the pond. Storm-to-storm comparisons are probably not valid. It is

probably more appropriate to utilize statistical characterizations of the inflow and outflow concentrations to evaluate

effectiveness or, if enough samples are collected (i.e., almost all storms monitored), to utilize total loads into and out of

the BMP.

Table 4 compares three of the methods, including percent removal by storm with a statistical characterization of

inflow/outflow concentration and a simple comparison of total loads in and out for the sampled storms for an example site.

The removals estimated differ by up to 18 percentage points. In this record, there are several storm events where inflow

concentrations were relatively low and therefore the system was not “efficient.” However, it was effective at maintaining

the effluent quality.

Table 4. Comparison of BMP Pollutant Removal Efficiency Techniques

Storm

Volume of

Flow (ft3

) 

Inflow = Outflow

Concentration

In Out

(mg/l)

Load

In Out

(lbs)

% Removal

by storm

1 445,300 352 24 9780 670 93%

2 649,800 30 25 1220 1010 17%

3 456,100 99 83 2820 2360 16%

4 348,111 433 141 9410 3060 67%

5 730,261 115 63 5240 2870 45%

Med 139 65 A

Cov 1.48 .86 28,470 9,970 V 48%

Mean 249 85 G

Conc 66% Loads 65%

note: 1 lbm = 2.2046 kg and 1 ft3 = 0.028317 m3

Based on these factors, it is recommended that a statistical characterization of inflows vs. outflows be utilized. Use

of the log-transform of EMCs is recommended. Tests of the applicability of a log transform should be made to support the

transform of data when sufficient data is available. Standard descriptive statistics, box-and-whisker plots, and normal

probability plots of the transformed data for both the inflow and outflow should be employed to clearly demonstrate not only

the differences in the mean EMCs, but also the effectiveness of the BMP throughout the range of influent and effluent

EMCs. This approach provides the ability to determine whether any apparent differences in inflow and outflow EMC

populations are statistically greater than zero. If enough data on storms is collected, (e.g., continuous samples over an
183

extended period including base flow measurements where significant), the total loads in and out may also be an acceptable

method. A graphical look at the distribution of contributing storms will often provide insight into the applicability of the

method, (e.g., do a small number of large storms dominate the resulting effectiveness value). 

The variability in runoff concentrations from event to event is large. In attempting to statistically characterize a BMP

influent concentration (and outflow), the more data the better. As mentioned above, there are a number of types of BMP

evaluations that can be conducted: (1) standard evaluation of a single BMP, testing input and output, (2) evaluation of

multiple BMPs within a basin (before/after or control basin), and (3) evaluation of a BMP with multiple inlets (where it might

be very difficult and expensive to evaluate the BMP utilizing input/output). All methods should require that a rigorous

statistical approach be applied in selecting the number of samples to be collected to help assure detection of a given level

of change. 

As an example of the number of samples required to detect a “true” difference, Table 5 presents an analysis of two of

the Portland monitoring stations (WCC, 1993) where 10 flow-weighted composite samples were collected. The Fanno Creek

station is a large (about 1,200 acres) residential catchment that is in an open channel, while the M1 station is a smaller

(about 100 acres) mixed land use station that is in a pipe. An analysis of a variance-based test was utilized with the

existing data to determine how many samples are estimated to be needed to detect a 5%, 20%, and 50% change in the

mean concentration at the station. The test was performed considering an 80% probability that the difference will be found

to be significant, with a 5% level of significance (Sokal and Rohlf, 1969). This analysis does not consider potential seasonal

effects on the collection of data as a factor. Even so, quite a large number of samples would be required to detect a 5%

to 20% difference in concentrations. In many locations, given that there may be only 10 to 20 storm events per year that

are large enough to monitor, it would take a number of years of sampling all storm events to be able to detect small

differences.

Table 5. Analysis of Sample Sizes Needed to Statistically Detect Changes in Mean Pollutant Concentrations from 2 Stations in Portland, Oregon

Number of Samples Required to Detect the Indicated %

Reduction in Site Mean Concentration*

 Monitoring Site Parameter 5% 20% 50%

R1 - Fanno Creek

Residential

TSS

Copper

Phosphorus

202

442

224

14

29

16

4

6

4

M1 - NE 122nd

Columbia

Slough Mixed Use

TSS

Copper

Phosphorus

 61

226

105

 5

15

 8

2

4

3

*80% certain of detecting the indicated % reduction in mean of the EMCs.

There are numerous examples in the literature where small differences (2 to 5%) have been reported based upon fewer

samples than indicated by this analysis. This highlights the need to be more rigorous with regard to statistical testing of

reported effectiveness estimates. To detect larger changes, the number of samples becomes reasonable. The mixed land

use catchment in Portland is currently being studied for the effectiveness of the implementation of a number of source

controls and other controls that do not lend themselves to input/output testing. Examples include maintenance changes

(catch basin cleaning, street sweeping); education (business and residences); tree planting, and others. Post-BMP

monitoring will be conducted along with qualitative evaluations.

Another approach that this study will be evaluating is the use of effluent data to compare to design criteria. It has been

suggested by some researchers that BMPs may be able to treat only to a given concentration and therefore, if relatively

clean water is entering a BMP, performance based upon efficiency may not fully characterize whether a BMP is welldesigned. An example of this is based upon Rushton et al. (1997). The pond was located at the Southwest Florida Water

Management District service office in Tampa. The drainage basin is 6.5 acres with about 30% of the watershed covered

by roof tops and asphalt parking lots, 6% by a crushed limestone storage compound and the remaining 64% as a grassed

storage area. The pond was modified twice after initial construction; therefore, there are three periods of performance data

for three different designs. The first pond had an average retention time of 2 days, the second 5 days and the third 15 days.

The second design added wetland features, while the third utilized deeper and larger pools. 
Figure 1 shows the input and output median concentrations in log based 10 scale as well as the 95% confidence

limits. The study reported that performance of the pond (defined as removal efficiency) decreased after the first

modification. What appears to be evident is that the average inflow concentrations were much lower during the second

period, while the outflow concentrations were about equal (less, but not statistically different from the first design). It

appears that with the original and first modified designs that the effluent level was not decreased. However, one could

not say that the BMP was any poorer in efficiency. The last design appears to have lowered the potential effluent

concentration, but the major difference in efficiency came from the significantly higher inflow concentrations during the

sampling period. This example points out the need to carefully think about whether pollutant removal efficiency is an

accurate representation of how well a BMP works or does not.

In many cases, there is a need to conduct dry weather analyses between storms on BMPs with dry weather flows.

It may be that pollutants captured during storms are slowly released during dry weather discharges.

Biological and downstream physical habitat assessments such as aquatic invertebrate sampling and habitat

classification should be explored as an alternative to just utilizing chemical measures of effectiveness (Maxted, 1999).

Long-term trends in receiving water quality, coupled with biological assessments, would likely be a much better gage of

the success of the implementation of BMPs, especially on an area-wide basis.

0.50 -

Median=

21 mg/l

i

1.32

11 mgA

11 mg/l

9 mgh

81 mgll

I

1 .Ol

0.86

5 mgA

0.00 A.--- -------. .,

.x- ^ ...-_- -.-. “----.---- I I-------- 8 lnflowtO90 Outfbw lrltlow fSO3-r Outflow hrlow 1 QQ4- OUtflOW

1900 1004 1993-l OS4 1995 IQQi-fSS5

Figure 1. Inflow and Outflow Log Mean TSS Concentrations (mg/l) and 95% Confidence Limits for Different Designs of a Wet Pond Located at SWFWMD

Service Office in Tampa, Florida.

Summary and Recommendations

There is a great need to have consistency with the constituents and methods utilized for assessing BMP

effectiveness. This paper has presented only some of the consistency issues. It is recommended that researchers who

undertake BMP effectiveness studies consider the recommendations suggested here, by Urbonas (1995) and other

recommendations based upon further analysis of this subject. It is the authors’ opinion that EPA should require studies

receiving federal funding to conduct BMP effectiveness studies that utilize standard methods as suggested here, together

with much still-needed detailed guidance on data collection and sampling methods to improve data transferability.

184
Acknowledgments

The authors wish to thank Gene Driscoll, Jonathan Jones, Bob Pitt, Bill Snodgrass, and Larry Roesner for their helpful

discussions and comments on the subject. Jonathon Jones, Jane Clary, and John O’Brien from Wright Water Engineers

developed the Database Structure and Platform as members of the ASCE project team. The Urban Water Resources

Research Council has provided very beneficial support and feedback. Finally, the assistance by EPA in funding this

cooperative agreement is acknowledged as well as the helpful participation of Eric Strassler and Jesse Pritts in reviewing

our work.

References

Driscoll, E.D., P.E. Shelley, and E.W. Strecker. 1990. Pollutant Loadings and Impacts from Storm Water Runoff, Volume

III: Analytical Investigation and Research Report. FHWA-RD-88-008, Federal Highway Administration.

Driscoll, E., G. Palhegyi, E. Strecker, and P. Shelley, 1989. Analysis of Storm Event Characteristics for Selected Rainfall

Gages Throughout the United States. Draft Report. Prepared by Woodward-Clyde for the U.S. Environmental Protection

Agency. 43pp.

Martin, E.H. and J.L. Smoot. 1986. Constituent-Load Changes in Urban Stormwater Runoff Routed Through a Detention

Pond-Wetland System in Central Florida. U.S. Geological Survey Water Resources Investigation Report 85-4310.

Maxted, J. 1999. Proceedings of the First International South Pacific Conference on Urban Stormwater

Ruston, B.T., Miller, C.H., Hull, H.C., and J. Cunningham, 1997. Three Design Alternatives for Stormwater Detention

Ponds. Southwest Florida Water Management District. Brooksville, FL.

Sokal, R.R. and F. James Rohlf. 1969. Biometry: The Principles and Practice of Statistics in Biological Research. W.

H. Freeman and Company. San Francisco, CA.

Strecker, E., 1994. Constituents and Methods for Assessing BMPs. Proceedings of the Engineering Foundation

Conference on Stormwater Related Monitoring Needs. Aug. 7-12, Crested Butte, CO. ASCE.

Strecker, E.W., Kersnar, J.M., Driscoll, E.D., and Horner, R.R. 1992. The Use of Wetlands for Controlling Storm Water

Pollution. The Terrene Institute. Washington, D.C.

Strecker, E. and B. Urbonas, 1995. Monitoring of Best Management Practices. Proceedings of the 22nd Annual Water

Reources Planning and Management Division Conference, ASCE, New York. pp. 48-51.

U.S. Environmental Protection Agency. 1983a. Final Report on the National Urban Runoff Program. Water Planning

Division, U.S. EPA. Prepared by Woodward-Clyde Consultants.

U.S. Environmental Protection Agency. 1993b. Memorandum. Office of Water Policy and Technical Guidance on

Interpretation and Implementation of Aquatic Life Metals Criteria.

Urbonas, B.R. 1994. Parameters to Report with BMP Monitoring Data. Proceedings of the Engineering Foundation

Conference on Storm Water Monitoring Related Monitoring Needs. August 7-12, Crested Butte, CO. ASCE.

Urbonas, B.R., 1995. “Recommended Parameters to Report with BMP Monitoring Data. J. Water Resources Planning

and Management, ASCE. 121 (l), 23-34.

Woodward-Clyde Consultants. 1993. Final Data Report: Data from Storm Monitored between May 1991 and January

1993. Submitted to Bureau of Environmental Services, City of Portland, OR.

185
Texas Nonpoint SourceBOOK Is Now On-Line!

http://www.txnpsbook.org

John Promise, P.E.

Director of Environmental Resources

North Central Texas Council of Governments, and

Chair, Water Resources Management Committee, American Public Works Association

Keith Kennedy

North Central Texas Council of Governments

Robert W. Brashear, Ph.D.,

Camp Dresser & McKee Inc.

Summary

The Texas Nonpoint SourceBOOKis an Internet-based resource that has been developed

to assist public works officials across Texas with storm water management. The

SourceBOOKprovides basic information about storm water quantity and quality impacts,

outlines how to develop and implement a local storm water management program, identifies

localized water quality issues, and provides an interactive database of more than 100 Best

Management Practices (BMP’s) to use in a variety of situations.

The Texas Nonpoint SourceBOOK provides information for the novice as well as the

experienced storm water manager. The project was funded by the Environmental

Protection Agency and matching funds from 20 local governments across Texas. The North Central Texas Council of

Governments (NCTCOG) served as project administrator. The SourceBOOKwas developed by a consulting team lead

by Camp Dresser & McKee Inc. (CDM). A Project Management Committee of local governments provided project

oversight. After extensive review via the Internet, the SourceBOOKwas officially endorsed by the Executive Committee

of the Texas Chapter - American Public Works Association (APWA). Five training workshops were conducted across

the state. The SourceBOOK is intended to be a living resource, with additions and changes occurring continually in

response to input from users. A feedback page allows direct input from the Internet.

Why a Texas Nonpoint SourceBOOK?

Recognizing the need for improved communication, cooperation, and education statewide on stormwater issues, a

Statewide Storm Water Quality Task Force was established by the Executive Committee of the Texas Chapter -

American Public Works Association. At an organizational meeting in February 1994, a Steering Committee and

subcommittees were formed. The various subcommittees immediately tackled the task of identifying current issues and

needs regarding storm water quality and nonpoint source pollution, particularly with respect to the needs of public works

officials across Texas.

Already known was that nonpoint sources, including stormwater, contribute to water pollution problems. The Water

Quality Subcommittee began to review data from the Texas Clean Rivers Program, available nonpoint source monitoring

data, and the State’s Nonpoint Source Water Pollution Assessment Report. They presented this assessment at

subsequent meetings of the Task Force. Water quality problems were known, but not how best to address them.

186
What was not known was the applicability and cost-effectiveness of Best Management Practices (BMPs) for

addressing many of the typical water quality pollutants: bacteria, pesticides, nutrients, metals, toxic chemicals, and

others. The Best Management Practices (BMP) Subcommittee surveyed local governments across Texas on BMP

implementation but found little technical data. It was evident that until questions such as applicability and costeffectiveness could be answered, local governments would not invest limited public funds on storm water controls.

A project was formulated that would provide the assistance local governments needed by developing an internetbased resource of storm water management information. At the time it was a striking idea, since the Internet was very

new and few local governments had any “on-line” experience. Using the emerging Internet would provide ready electronic

access and would allow for the use of new technologies in communication. This resource was to be called the Texas

Nonpoinr SourceBOOK, and would be developed in both “hardcover” and electronic form. A grant application, submitted

to the Texas Natural Resource Conservation Commission under the Section 319(h) Nonpoint Source Program, was

awarded in the spring of 1996. Work on the project began in September, 1996.

How Was the Texas Nonpoint SourceBOOK Developed?

The North Central Texas Council of Governments provided staff support and general administrative oversight. To

guide the development of the SourceBOOK, a Project Management Committee was established from the Texas ChapterAPWA membership. Among its first tasks was issuing a Request for Proposals for professional consultant assistance,

and selecting the consultant finalists. From the finalists the Committee selected a consultant team led by the firm Camp

Dresser & McKee Inc., in association with Espey Huston & Associates, Inc.; Center for Watershed Protection; Booth, Ahrens

& Werkenthin, P.C.; Carter Burgess; and Pavlik & Associates. Together, the committee and consultants used the State’s

Nonpoint Source Water Assessment Report and supporting information to identify particular pollutants from priority

watersheds and related pollution prevention BMPs.

During FY97, the Project Management Committee worked with the consultant to establish the format of the Texas

Nonpoint SourceBOOKon the Internet. Presentations on local BMP experiences were made at the TX-APWA Short

Course at Texas A&M in February, 1997. Initial consultant materials were reviewed by the TX-APWA general

membership at its summer, 1997, Annual Meeting. A draft of the Texas Nonpoint SourceBOOK was presented to the

TX-APWA general membership at the February 1998 Short Course, and local government comments were solicited.

The TX-APWA Executive Committee endorsed the Texas Nonpoint SourceBOOKin February, 1999. It is available

through the Internet and on CD-ROM for use by local governments across Texas. The Committee and consultant

conducted technology transfer and training workshops on storm water management and the Texas Nonpoinf SourceBOOK

at five regional one-day workshops across Texas during February and March of 1999.

How is the Texas Nonpoint SourceBOOK Organized?

The SourceBOOK is designed to make use of the capabilities of the Internet. This includes the ability to organize and

present textual and graphical information through common browser formats, as well as providing active links to related sites.

The design of the content of the SourceBOOKmaximized the use of existing web sources wherever possible.

The content of the SourceSOOKconsists of a set of modules:

Introduction and Overview

* About This Site

* Frequently Asked Questions (FAQs)

* Related Links

. Nonpoint Source News

187
. Post Your Feedback

Module 1 -- Nonpoint Source Management 101

. History of Nonpoint Source Management

. Urban Nonpoint Source Primer

. Controlling Urban Runoff--Guidance for Beginners

. Selecting the Right BMP -- Guidance for Beginners

. Planning Your Stormwater Management Program - Guidance for Beginners

- Glossary

Module 2 -- Urban Runoff Management Programs

. Introduction

. The Planning and Goal Setting Process

. Planning and Program Approaches

. Funding Mechanisms

. Measuring Effectiveness of Management Programs

. Implementation Strategies

. Case Studies

. Bibliography

. Additional Resources

Module 3 -- Characterizing Urban Waterways

. Urban Runoff Flow and Water Quality

9 Assessing Urban Waterways

. Water Quality and Other Watershed Physical Characteristics in Texas

Module 4 -- Runoff Quality Best Management Practices

* Selecting Management Practices

. Housekeeping Practices

* Source Control Practices

. Treatment Control Practices

. Interactive BMP Selector

188
What Does Each Module Provide in the Texas Nonpoint SourceBOOK?

Module 1, “Nonpoint Source Management 101,” is a primer for beginners on urban stormwater management. It

quickly establishes that storm water quality and quantity management need to be addressed as one integrated program

within a local government. It provides guidance on regulatory issues, basic axioms of runoff control, and the use of

pollution prevention, source and treatment controls.

Module 2, “Urban Runoff Management Programs,” describes the process to be used to manage urban runoff within

the overall framework of the city, county, or special district. Particular attention is placed on the key institutional and

financial components necessary for a successful ongoing program.

Module 3, “Characterizing Urban Waterways,” begins with a generic discussion of urban runoff flow and water quality

relationships. Considerable attention is then given to proper techniques for monitoring urban waterways and stormwater

runoff. The majority of the module focuses on Texas-specific information. Descriptions of known water quality problems

can be accessed for the entire state. Each regional planning area and basin has specific information on water bodies,

r

il#rm z-1 THE “RMP PLANNING PROCESS

189
5.0 Other Watershed Physical Characteristics by Region

watershed characteristics, annual precipitation and runoff, major soil types, and the like. There are many “hot” links to

real-time gauging stations, local programs, and state/federal sites, such as EPA’s Surf Your Watershed.

Module 4, “Runoff Quality Best Management Practices,” provides guidance on the selection of Best Management

Practices for pollution prevention, source control, and treatment control. Considerable effort was placed on gathering

the most current information on more than 100 BMPs and review by the Project Management Committee of local

governments. Each BMP includes detailed information, such as performance data, photographs, and relevant reference

citations. An innovative BMP Interactive Selector was developed for the SourceBOOK. It enables the user to peruse

BMP’s in each category, or to input several characteristics specific to their situation and request a set of the most

applicable BMPs.

190
191
A Comparison of the Long-Term Hydrological Impacts of

Urban Renewal versus Urban Sprawl

Jon Harbor, Suresh Muthukrishnan, and Shilpam Pandey

Departments of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana

Bernie Engel, Don Jones, and K.J. Lim

Departments of Agricultural and Biological Engineering

Purdue University

West Lafayette, Indiana

Abstract

Recent concern over environmental and economic impacts of urban sprawl has focused renewed attention on the

importance of making full use of existing urban areas. Revitalizing former industrial, commercial, and residential areas

often involves changes in land use type or intensity of use. It is important to have the ability to evaluate the long-term

hydrological impacts of such changes. These impacts can then be placed within the context of impacts that similar land

uses would have if a decision were made to place them in the urban fringe (urban sprawl) rather than in existing urban

areas (urban renewal).

In this study, we illustrate how the Long-Term Hydrological Impact Analysis (L-THIA) tool can be used to compare

the hydrological impacts of land use change in existing urban areas versus change in the urban fringe. L-THIA is a simple,

comparative tool that requires the user to provide information on land use and soil type for existing and future/planned

conditions. The tool combines this information with local rainfall datato calculate long-term average annual surface runoff

under existing and future/planned conditions. L-THIA analyses can be run directly at our web site for locations throughout

the U.S. where the curve number technique is already routinely used (http://danpatch.ecn.purdue.edu/-sprawl/L-THIA).

By performing analyses of renewal versus conversion of agricultural land at the urban fringe, it is possible to provide a

comparative assessment of impacts. This initial comparison can be helpful in educating the general publicand decisionmakers, thereby raising awareness of this element of the set of variables that are considered in land use decisions.

Introduction

Because almost every major North American city had been founded by 1900, the dominant form of urban

development during the 20th Century has been growth on the outer edges of existing cities, or just beyond city limits

(Orum, 1995). With improvements in transportation and communications, the need for people to be clustered in highdensity central areas has decreased (Chinitz, 1991), encouraging decentralization, suburbanization, and sprawl. In the

United States, 87% of the population now lives in metropolitan areas and their hinterlands (Angotti, 1995), and steady

infilling between urban areas has resulted in the development of megalopolises such as the Philadelphia - Boston -

Washington DC - New York urban corridor. Even metropolitan areas which are stagnating or declining in terms of total

population are still growing in terms of total built area because of low-density suburban growth (Johnston, 1982).

Decentralization and suburbanization have changed the relative importance of the core areas of cities (Richardson,

1982). Although these central areas were the sites of initial city growth and development, many cities are now faced with

the challenge of revitalizing these once vibrant central industrial, commercial, and residential areas that have been in

decline in recent decades:. The following quote reflects efforts to slow the tide of migration from urban centers.

192
“To combat the number of people fleeing [Chicago] for the suburbs, developers have lured middle-class home

buyers back with promises of safe neighborhoods and affordable homes. Chicago also leads the nation in

converting office and warehouse property into residential space such as condominiums and rental units, often

targeted to low- and moderate-income buyers.” (Heavens, 1999)

At the same time that city administrations have been coping with the challenges of urban core renewal, suburban and

rural communities have become increasingly concerned about the environmental, economic, social, and aesthetic impacts

of continued urban growth at the fringes of developed areas (these later concerns are often grouped under the term urban

sprawl). Preservation of prime farmland and protection of rural areas have become important concerns, alongside a

growing emphasis on combating the impacts of continued sprawl on flooding, groundwater recharge, air pollution, climate,

ecology, and habitat fragmentation (Schueler, 1994). Although there is considerable interest3 in revitalizing urban cores,

especially if this reduces urban sprawl, to accomplish this requires that the decision-making process for urban and

suburban planning include consideration of the environmental as well as the economic aspects of land use.

Land use decisions are highly complex, involving consideration of economics, infrastructure, politics, labor and

population dynamics, and the environment. The planning process requires collection and comparison of a wide array of

data, usually with the goal of providing a planned solution that meets goals based on sustainable growth in industry and

commerce. However, increasing public and political concern over the environmental aspects of urban development has

raised the profile of efforts to develop efficient and environmentally sustainable urban environments. The key components

of environmentally sound urban development include land use patterns that minimize environmental impacts (Arendt,

1996), efficient automobile and pedestrian traffic, and the use of energy saving and environmentally sound building

designs. When attempting to balance economic and environmental concerns, it is important to quantify the differential

environmental impacts of alternate land-use scenarios. Objective measures of differential impacts provide a rational basis

for decision-making. In addition, they can be used to educate the public and key decision-makers in government and the

private sector about the level of environmental benefit that can be gained from alternative land-use decisions.

The aim of the work presented here is to demonstrate the application of an impact assessment tool in evaluating the

long-term hydrologic impact of development consistent with urban renewal versus the impact of an identical development

located at the urban fringe. Although the general outcome of such a comparison is unlikely to surprise anyone, the

advantage of quantifying differential impacts is in providing an objective numeric measure that is much easier to include

in decision-making than vague subjective assessments of environmental benefits.

Long-Term Hydrologic Impact Assessment (L-THIA)

In response to concerns from local planners that they had no simple, objective way to assess the impacts of alternate

development plans on surface water runoff and groundwater recharge, a Long-Term Hydrologic Impact Assessment tool

(L-THIA) has been developed (Harbor, 1994; McClintock et al., 1995; Ogden, 1996; Grove, 1997; Bhaduri et al., 1997;

Bhaduri, 1998; Minner, 1998; Minner et al. 1998; Lim et al., 1999; Leitch and Harbor, in press). L-THIA uses readily

available data on soils, climate, and land use to estimate long-term surface water runoff. By running the model for current

conditions, and then with changed land uses, the user can simulate the potentialimpact of land use change. The method,

initially developed as a simple spreadsheet application (Harbor, 1994), is based on the U.S. Department of Agriculture’s

curve number (CN) method for relating precipitation and runoff as a function of land use and soil type (USDA, 1983,

1986). The CN method was selected because it forms the basis of other commonly used hydrologic models, thus the

data required for its use is readily available in most planning settings. Because of the reliance on the CN method, L-THIA

applies directly to those areas where the CN method is routinely used. Subsequent development of the L-THIA method

has included provision of a Geographic Information System (GIS) version (Grove, 1997), addition of nonpoint source

pollution loadings to land uses (Bhaduri, 1998), and development of an Internet--accessible version of the method (Lim

et al., 1999).

In the curve number technique, the land use and hydrologic soil type of an area are used to derive a CN value (values

typically range from 30 to 98). For any given daily precipitation, surface runoff is then computed from empirically based

relationships between rainfall, CN, and runoff. Although most commonly used to estimate runoff for extreme storm

events, in L-THIA the CN technique is used to determine daily runoff for a 30-year time series of daily precipitation values.

193
Average annual runoff is calculated for each CN to provide a measure of long-term average impact, rather than simply

impact on isolated extreme storm events. To compare different land use change options, pre-development and postdevelopment average annual runoff can be calculated for each scenario. The L-THIA method is freely available at

http://danpatch.ecn.purdue.edu/-sprawl/LTHlA. This site includes information on the technique and its application, as

well as access to US climate and soils data necessary to run analyses. Users can submit land use and soil information

through a spreadsheet-style interface (Figure 1). Analyses are performed on a server at Purdue University and results

are delivered back to the user in the form of tables and graphs.

-

b Home

b Lthia

binput

LTHIA

&one; Term Hydroloejc Impact Assessment) WWW

Figure 1. L-THIA WWV Input Screen at http://danpatch.ecn.purdue.edu/-sprawl/LTHIA.

A Comparison of Core Renewal versus Fringe Development

Study Scenario

The L-THIA tool can be used to examine the relative impact of land use change in the form of an urban renewal

project; replacing underused or abandoned commercial, residential, and industrial buildings in an urban core region;

versus an urban sprawl project; replacing agricultural land at the edge of a city. For the sake of illustration, consider

planning a 70 Ha major commercial development with urban core and urban fringe location alternatives. Although the

location decision-making process will be driven by economic and infrastructure concerns, also assume that differential

environmental impact is important in decision--making, perhaps as a result of political or regulatory pressure. In the

context of improving urban environments then, an important question is the extent to which placing this development in

an urban core region would have different hydrologic impacts than placing it at the city fringe.

To simulate this situation, consider two possible sites in the Chicago area. The first is in the urban core, and currently

consists of a mix of residential, industrial, and commercial properties that are unused or underused (Figure 1). The

second possible site is on the urban fringe, and currently is used for agriculture. For simplicity we assume that both sites

are on the same type of soil (from a hydrologic perspective), although in a real world example this might not be the case.

In each case, we use the L-THIA web tool to analyze how average annual runoff will change if the site is converted to

194
solely commercial use (Figure 1). In the L-THIA input and output, the urban core site is labeled “YEAR 1 ‘I, the urban

fringe agricultural site is labeled “YEAR 2” and the commercial land use for both sites is labeled “YEAR 3.” The L-THIA

web tool uses the “YEAR” designation for different scenarios because analyses are typically for land use changes over

time.

Results

For the example described here, placing a commercial development in an urban core region, replacing an existing

mix of urban land uses, increases average annual runoff by 58% compared to the initial situation (Table 1 and; Figure

2). Note that the levels of impact given in Table 1 do not depend on the size of the commercial development; the same

percent increase applies regardless of area. Runoff increases because land uses with less impervious cover, such as

residential, are replaced by commercial land use that has a higher percentage of impervious area. In contrast, for the

urban fringe location, replacing agriculture with commercial use increases runoff by 670% (Table 1 and Figure 2), a tentimes greater impact. Runoff increases so dramatically because agricultural use on relatively permeable soil is replaced

by very extensive impervious surfaces.

Table 1. Averaae annual runoff deoths and chanae for commercial development (post-development) in the urban core versus the urban fringe. Results

are for the specific example described in the text.”

Urban Core

Urban Fringe

Pre Development Post Development Increase in Runoff (%)

Average Annual Runoff Average Annual Runoff

(mm) (mm)

81.8 129.3 58

16.8 129.3 670

Core Fringe Commercial

Figure 2. Average annual runoff volumes for commercial development, the urban core mixed-use, and the urban fringe agricultural use. The much larger

difference between the fringe location runoff volume and the commercial case indicates that fringe development will have the largest hydologic impact.

Note that the runoff volume is simple the average annual runoff depth (Table 1) multiplied by the site area. Results are for the specific example described

in the text.

195
Discussion and Conclusions

The straightforward example presented here indicates that developing a commercial site in an urban core versus and

urban fringe location can have a very significant impact on the level of disturbance of the hydrologic regime. For the

Chicago example presented here, the urban fringe location produces an approximately ten times larger impact than the

urban core location. Clearly, from a solely hydrological standpoint, the urban core location is a better choice than the

fringe location. Although this is a hypothetical example, it illustrates the relative ease of use of the L-THIA tool, and more

importantly demonstrates an accessible way to provide a quantitative estimate of the relative impacts of different land use

decisions. More complex land use mixes and soil types can be run on the L-THIA web tool, either in the spreadsheet

version or in a GIS version also available at the web site. Thus, more sophisticated comparative analyses can be

performed.

In most cases, an L-THIA analysis provides a result that shows that renewal of existing areas has less hydrologic impact

than development of an area with rural use. This is not a surprise, rather the value of the tool is that it provides a context

for understanding and considering the magnitude of this difference in the decision-making process. For areas where

problems such as groundwater supply and downstream flooding are important, the scale and magnitude of the hydrologic

impact can be of considerable importance and can be considered alongside other concerns, such as infrastructure and

economic viability. We suggest use of tools such as L-THIA as part of the planning process, to ensure that land use

decisions are made after consideration of a full range of concerns, including environmental parameters as well as

economic, infrastructure, and political issues.

Acknowledgements

Development of the L-THIA tool is being supported by grants from the Environmental Protection Agency, Region 5.

References

Angotti, T., 1995. The Metropolis Revisited. Futures, 27: 627-639.

Arendt, R., 1996. Conservation design for subdivisions, a practical guide to creating open space networks. Washington

D.C., Island Press.

Bhaduri, B. 1998. A geographic information system based model of the long-term impact of land use change on non-point

source pollution at a watershed scale. Unpublished Ph.D. dissertation, Purdue University, West Lafayette, Indiana47907-

1397.

Bhaduri, B., M. Grove, C. Lowry, and J. Harbor. 1997. Assessing the long-term hydrologic impact of land use change.

Journal of the American Water Works Association. 89:94-l 06.

Chinitz, B. 1991. A Framework for Speculating about Future Urban Growth Patterns in the US. Urban Studies, 28:939-

959.

Grove, M. 1997. Development and application of a GIS-based model for assessing the long-term hydrologic impacts of

land-use change. Unpublished MS Thesis, Purdue University, West Lafayette, IN 47907-l 397.

Harbor, J. 1994. A practical method for estimating the impact of land use change on surface runoff, groundwater

recharge and wetland hydrology. Journal of American Planning Association, 60:91-104.

Heavens, A.J., 1999, Building Anew in the City. Philadelphia Inquirer (09/12/99) Ll .

Johnston, R., 1982. The American Urban System: A Geographical Perspective. New York: St. Martin’s Press.

Leitch, C. and Harbor, J., (In Press) Impacts of land use change on freshwater runoff into the near-coastal zone, Holetown

watershed, Barbados: Comparisons of long-term to single-storm effects. Journal of Soil and Water Conservation.

196
Lim, K.J., Engel, B., Kim, Y., Bhaduri, B., and J. Harbor. 1999. Development of the long term hydrologic impact

assessment (L-THIA) WWW systems. Paper No 992009, ASAE, St. Joseph, Ml.

McClintock, K., J. Harbor, and T. Wilson. 1995. Assessing the hydrologic impact of land use change in wetland

watersheds, a case study from northern Ohio, USA. In: McGregor, D. and Thompson, (Eds.) Geomorphology and Land

Management in a Changing Environment, pp.1 07-l 19.

Minner, M., 1998. Sensitivity analysis and advanced applications of L-THIA. Unpublished MS Thesis. West Lafayette,

IN: Purdue University, Department of Earth and Atmospheric Sciences, West Lafayette, IN 47907-l 397.

Minner, M., Harbor J., Happold S., and P. Michael-Butler, 1998. Cost Apportionment for a Storm-Water Management

System, Applied Geographic Studies, 2:247-260.

Ogden, M., 1996. Development and Land Use Changes in Holetown, Barbados: Hydrologic Implications for Town

Planning and Coastal Zone Management. Unpublished M.U.P. Thesis. Montreal: McGill University, School of Urban

Planning.

Orum, A., 1995. City-building in America. Westview Press, Boulder, CO.

Richardson, J., 1982. The Evolving Dynamics of American Urban Development, in: Cities in the 21st Century. Gappert,

G. and Knight, R. (Eds.) Urban Affairs Annual Reviews, 23.

Schueler, T., 1994. The importance of imperviousness. Watershed Protection Techniques, 1:100-l 11.

U.S. Department of Agriculture, Soil Conservation Service, 1983. Computer programs for project formulation - hydrology.

Technical Release 20.

U.S. Department of Agriculture, Soil Conservation Service, 1986. Urban hydrology for small watersheds. Technical

Release 55.

197
Comparative Nutrient Export And Economic Benefits of

Conventional And Better Site Design Techniques

Jennifer Zielinski, Deb Caraco, and Rich Claytor

Center for Watershed Protection

Ellicott City, Maryland

Better site design describes a fundamentally different approach to the design of residential and commercial

development projects. It seeks to accomplish three goals at every development site: to reduce the amount of impervious

cover, to increase the amount of natural land set aside for conservation, and to use pervious areas for more effective

stormwater treatment.

When designing new residential developments, planners have the opportunity to reduce stormwater runoff and

pollutant export through better site design techniques. The better site design techniques applied to these developments

are referred to here as “open space design,” and present an alternative to conventional residential subdivisions. Also

known as cluster development, open space design concentrates density on one portion of a site in order to conserve open

space elsewhere by relaxing lot sizes, setbacks, frontages and road section and other lot geometry. Open space design

also consists of:

. installing narrower streets and shorter driveways

. spreading stormwater runoff over pervious areas

. using open channels rather than curb and gutter

. clustering development to conserve forests and natural areas

. reducing the area devoted to turf

l protecting stream buffers

. enhancing the quality of septic system effluent in areas where sewage is disposed of on-site

When these techniques are applied together, the cumulative benefits of better site design can be impressive.

Documenting the precise benefits is difficult, however, since few developments incorporating better site design techniques

have been built, let alone monitored.

As most better site design techniques are non-structural in nature, the achievable benefits will vary depending on the

unique characteristics of each development site and the actual site planning practices applied. Also, since better site

design techniques are commonly applied together, it has been difficult to accurately quantify their individual nutrient

removal benefits. Many local governments, consultants, and developers have expressed a strong desire for clear

documentation of these presumed benefits.

To help meet this need, the Center for Watershed Protection (CWP) recently completed a study to document the

comparative nutrient export and economic benefits of conventional and better site design techniques. The simple

assessment methodology analyzed both the residential and commercial environment through four real-world development

case studies in the Chesapeake Bay watershed. This paper presents the results of the residential component of that

project, including the incorporation of open space design techniques into the redesign of two residential case studies; the

resultant hydrologic, nutrient export, and economic benefits; and finally, the implications of our findings for the watershed

manager.

198
Methodology

The basic method used in the Nutrient Loading from Conventionalandlnnovative Site Developmentproject (Caraco,

et al., 1998) conducted by CWP is a redesign analysis that compares conventional and better site design at actual project

sites using a simplified model.

CWP first assembled plans of previously developed sites representative of typical development scenarios across the

Chesapeake Bay, including a medium-density residential development from Virginia’s Piedmont, a large-lot single family

residential subdivision from Maryland’s Eastern Shore, a retail strip mall from Frederick County, Maryland, and a

commercial office park located outside of the District of Columbia in suburban Maryland. Each site was then “redesigned”

using better site design techniques.

The Simplified Urban Nutrient Output Model (SUNOM) was then used to compare each conventionally designed site

to the redesign. SUNOM is a spreadsheet model that computes the hydrologic budget, infrastructure cost and nutrient

export from any site, using common site planning variables. The model provides watershed practitioners with a simple

tool to compare the costs and benefits of better site design. It is not meant to be used as a method for determining actual

stormwater runoff and nutrient loading from a development site. To obtain accurate numbers for this, a more detailed

model should be used or on-site monitoring should be conducted.

Model input includes basic site planning variables that can be directly obtained or measured from a typical

development submittal to a land use authority, including total drainage area, length of sidewalks, total impervious cover,

linear feet of roads, lawn cover, utilities (length and type), forest cover, size, type, and length of stormwater conveyance,

riparian forest cover, size and type of stormwater practices, soil type(s), and method of wastewater treatment. Default

data are provided for many parameters and many of these assumptions can be changed based on site specific

information.

SUNOM is governed by the principles of a simplified water balance. In addition to annual runoff and infiltration,

SUNOM computes the annual nutrient load from each development site in pounds. In brief, the surface nutrient export

from each site is estimated using the Simple Method (Schueler, 1987). This export is then adjusted to reflect the mean

removal capability of stormwater BMPs where present (Schueler, 1997). The subsurface component of the model utilizes

annual subsurface recharge rates (based on the site’s prevailing hydrologicsoil group) and monitored baseflow nutrient

concentrations in the receiving water to estimate the annual subsurface nutrient export from urban areas. These values

are then adjusted for the area of the site that cannot recharge (i.e., impervious cover) or are hindered from infiltrating by

other conditions (e.g., compacted urban turf). The model also calculates the cost of development utilizing previously

published or user-specified unit costs and predictive equations for infrastructure, stormwater management, landscaping,

and septic systems.

For each case study, SUNOM was used to compare the annual hydrologic budget and annual nutrient export under

five development scenarios: pre-developed conditions, conventional design without stormwater practices (uncontrolled),

conventional design with stormwater practices (controlled), design incorporating better site design techniques without

stormwater practices (uncontrolled), and design incorporating better site design techniques with stormwater practices

(controlled). The cost of development associated with each design was also estimated.

Case Study #l: Duck Crossing, A Low Density Residential Subdivision

Duck Crossing, a large-lot residential development, is located in Wicomico County on Maryland’s Eastern Shore.

Prior to development, the parcel was representative of the typical terrain on Maryland’s coastal plain, with very little

gradient. The site contained tidal and non-tidal wetlands, natural forest, meadow, the 1 00-year floodplain, as well as three

existing dwellings with on-site sewage disposal.

The large-lot subdivision of single family homes, constructed in the 1990’s, (Figure 1) contains eight new residential

lots, each of which are 3 to 5 acres in size with houses set far back from the street. The street is wide given the few

homes that are served, ends in a large cul-de-sac, and is lined with a sidewalk. Each lot has an on-site private septic

199
Figure 1. The conventional design of Duck Crossing, a low density residential subdivision on Maryland’s Eastern Shore.

system, with a septic reserve field of about 10,000 square feet. Individual home property lines extend to the protected

tidal marsh, which is the only common open space on the site. Stormwater management consists of street runoff

conveyed by curb and gutter to a storm drain system that discharges to a small wet pond.

The major better site design techniques applied when redesigning this site (Figure 2) included:

. conservation of tidal and non-tidal wetlands and forested areas

. a lOO-foot buffer along tidal and non-tidal wetlands

. clustering development to provide additional open space

. identification of potential development and open space areas based on location of sensitive areas, loo-year

floodplain, and potential septic field areas

l distribution of stormwater treatment practices throughout the site

. use of a narrower access road; shorter, shared driveways; and wood chip paths through community open space

instead of sidewalks along the road

. use of shared septic systems utilizing more advanced re-circulating sand filter technology

The open space design resulted in reduced impervious cover, reduced stormwater runoff, increased stormwater

infiltration, and reduced infrastructure cost over the conventional design.

Case Study #2: Stonehill Estates, A Medium-Density Residential Subdivision

Stonehill Estates is located in Stafford County just north of Fredericksburg, Virginia. The original site was almost

entirely forested in a mix of mature deciduous hardwoods, with perennial and intermittent streams, and non-tidal wetlands.

An existing network of public water and sewer lines serves the site and road access to the subdivision is by two existing

streets.

200
Figure 2. The open space design of Duck Crossing.

The conventional design produced a total of 108 house lots, each of which are about 9000 square feet in size (Figure

3). The subdivision is quite typical of a medium-density residential subdivision developed in the last two decades in the

Mid

Figure 3. The conventional design of Stonehill Estates, a medium density residential subdivision in Stafford County, Virginia.

Atlantic with uniform lot sizes and shapes, and generous front setbacks. The streets were 34 and 26 feet wide, numerous

cul-de-sacs were used as turnarounds, and sidewalks were generally installed on both sides of the street. With the

exception of a small tot-lot, the majority of the open space is unbuildable land, such as floodplains, steep slopes,

wetlands, and stormwater management areas. Street runoff is conveyed by curb and gutter to a storm drain system that

discharges to the intermittent stream channel. It then travels to a dry extended detention pond, which is primarily used

to control flooding, but also provides limited removal of stormwater pollutants.

201
The open space design also results in 108 lots, but these were slightly smaller with an average size of 6,300 square

feet. The design also incorporates many techniques of open space design as advocated by Arendt (1994). The design

techniques employed in the redesigned site (Figure 4) include:

Figure 4. The open space design of Stonehill Estates.

. identify sensitive natural features, including mature forest and wetland, to be protected

. incorporate a minimum 1 00-foot buffer along all perennial and intermittent streams

. maximize the amount of community open space and preservation of natural areas

. maintain the same number of lots as the conventional design

l provide open space adjacent to as many lots as possible

. incorporate stormwater management attenuation and treatment throughout the site

. use narrower streets, loop roads, shorter driveways, and fewer sidewalks

. allow for irregular shaped lots and shared driveways

. manage stormwater in a “treatment train” with bioretention facilities that discharge to a small but more effective

wet pond

The open space design resulted in reduced impervious cover, reduced stormwater runoff, increased stormwater

infiltration, and reduced infrastructure cost over the medium density subdivision conventional design (Table 1).

The Benefits of Open Space Design

For both of these case studies, application of the open space design techniques resulted in reduced impervious cover,

which translates directly to reduced stormwater runoff. Other “redesign” studies recently conducted in Delaware,

Maryland, and Virginia have provided similar results. These combined results consistently demonstrate that better site

design can reduce impervious cover by 25 to nearly 60% and stormwater runoff by 4 to over 60% for a range of

subdivisions (Table 1).

202
Table 1. Redesign Analyses Comparing Impervious Cover and Stormwater Runoff from Conventional and Open Space Subdivisions

Residential Conventional Zoning for

Subdivision Subdivision

Duck Crossing 3 - 5 acre lots

Stonehill Estates l/3 acre lots

Impervious Cover at the Site % Reduction in

Conventional Open Space Stormwater

Design Design Net Change Runoff

8% 5% - 35% 23%

27% 21% - 24% 24%

Remlik Hall ’ I 5 acre lots I 5.4 % I 3.7% I -31% I 20%

Tharpe Knoll 2

Chapel Run 2

Pleasant Hill 2

Prairie Crossing ’

puckingham Greene

1 acre lots

% acre lots

% acre lots

% - l/3 acre lots

1 I8 acre lots

13%

29%

26%

20%

23%

7%

17%

11%

1 a%

21%

- 46% 4%

-41% 31%

- 58% 54%

- 20% 66%

- 7% 8%

Belle-Hall 4

I High Density I

35% I

20% - 43% 31%

sources: ’ Maurer, 1996; 2 DE DNREC, 1997; 3Dreher, 1994; and 4SCCCL, 1995.

For both Duck Crossing and Stonehill Estates, the conventional design results in the highest annual volume of runoff

and the lowest volume of infiltration, as was expected. Of particular interest is the fact that the controlled conventional

design results in a higher annual runoff volume and a lower infiltration rate than the uncontrolled open space design. This,

however, should not imply that better site design alone, without structural stormwater management, is sufficient in

controlling stormwater runoff from this site since the open space designs do not come close to replicating pre-developed

hydrology.

Less impervious cover and stormwater runoff, in turn, translates directly to smaller pollutant loads. Reducing the

impervious cover, preserving natural areas, and providing multiple stormwater practices in series reduced nutrient export

for both case studies. However, neither open space design meets pre-development nutrient loads.

One area of particular interest for Duck Crossing is the implication of on-site sewage disposal systems. The

conventional design included astandard septictankand field for each lot, which resulted in phosphorus and nitrogen loads

that far exceeded pre-development levels. Recirculating sand filters were used in the open space design, instead of

conventional septic systems, because they yield better nitrogen removal efficiencies and are actually less expensive to

construct. This resulted in a much lower nutrient output from the entire site. However, even in the open space design,

the septic systems are the predominant source of nutrients.

For both case studies, the total infrastructure costs include the sum of the estimated costs of stormwater

management, storm drainage, paving, sidewalk, curb and gutter, landscaping and reforestation, water, sewer and septic

systems. In both cases, the open space design resulted in a cost savings. Costs associated with grading, erosion and

sediment control, building construction and other incidental costs associated with land development were not analyzed.

In general, these costs should be comparable between the two development options. If anything, the grading and erosion

and sediment control costs should be lower with the open space design since less land is disturbed.

Several other studies have also shown that open space development can be significantly less expensive to build than

conventional subdivision developments. Most of the cost savings are due to savings in road building and stormwater

management conveyance costs. The use of open space design techniques at a residential development in Davis,

California provided an estimated infrastructure construction costs savings of $800 per home (Liptan and Brown, 1996).

Other examples demonstrate infrastructure costs savings ranging from 11 to 66%. Table 2 lists some of the projected

construction cost savings generated by the use of open space redesign at several residential sites.

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Table 2. Projected Construction Cost Savings for Open Space Designs from Redesign Analyses

Residential Subdivision

Duck Crossing

Stonehill Estates

% Construction

Savings

12%

20%

Notes

Includes roads, stormwater management, and reforestation

Includes roads, stormwater management, and reforestation

I

52% Includes costs for engineering, road construction, and obtaining water

and sewer permits I

Tharpe Knoll 2

I

56% Includes roads and stormwater management

Chapel Run *

Pleasant Hill 2

Buckingham Greene *

64%

43%

63%

Includes roads, stormwater management, and reforestation

Includes roads, stormwater management, and reforestation

Includes roads and stormwater management

Sources:’ Maurer, 1996; ‘DE DNREC, 1997.

Implications for the Watershed Manager

Better site design reduces impervious cover, conserves larger contiguous natural areas, and incorporates more

advanced stormwater treatment, which results in reduced stormwater runoff, increased infiltration, and reduced nutrient

export. Hopefully, the results of this study, as well as other redesign analyses, will answer some of the questions of local

governments, consultants, and developers as to the benefits of better site design.

However, there may still be difficulties to overcome before better site design becomes a reality and common practice

in many communities. Once there is a willingness to incorporate better site design techniques into new developments,

many communities may find that their existing development codes and ordinances are in conflict with the goals of better

site design. For example, many local codes and ordinances require excessive impervious cover in the form of wide

streets, expansive parking lots, and large-lot subdivisions. In addition, there are generally few, if any, incentives or

requirements for developers to conserve natural areas. When obstacles to better site design are present, it is a sign that

a community may want to reevaluate and consider changing some of its local codes and ordinances.

In 1997, CWP convened a national site planning roundtable to address this very issue. During the 18-month

consensus-building process, a diverse cross section of national planning, environmental, home builder, fire and safety,

and public works organizations (as well as local planning officials) crafted 22 model development principles to help further

better site design at the local level. This national roundtable is serving as a model for local government implementation

of better site design principles.

Recently, Frederick County, Maryland, initiated a local roundtable to take a critical look at its own development rules.

Members of the development community in partnership with local planning and zoning and public works staff are meeting

to identify and overcome impediments to better site design that are embedded in the county’s codes and ordinances.

The outcome of the consensus process should be development rules that encourage rather than discourage the

application of better site design techniques.

Changing local development rules is not easy. Progress toward better site development will require more and more

local governments to examine their current practices in the context of a broad range of concerns, such as how changes

will affect development costs, local liability, property values, public safety, and a host of other factors. Advocates of better

site design will have to answer some difficult questions from fire chiefs, lawyers, traffic engineers, developers, and many

others in the community. Will a proposed change make it more difficult to park? Lengthen response times for emergency

vehicles? Increase risks to the community’s children? True change occurs only when the community addresses these

and other questions to the satisfaction of all interests.

204
Arendt, Randall. 1994. Designing Open Space Subdivisions. Natural Lands Trust, Media, PA.

Caraco, D., R. Claytor, and J. Zielinski. 1998. Nutrient Loading from Conventional and Innovative Site Development.

Center for Watershed Protection. Ellicott City, MD.

Delaware Department of Natural Resources and Environmental Conservation. 1997. Conservation Design for

Stormwater Management. Delaware Department of Natural Resources and Environmental Conservation, Dover, DE.

Dreher, D.W. and T.H. Price. 1994. Reducing the Impacts of Urban Runoff: The Advantages of Alternative Site Design

Approaches. Northeastern Illinois Planning Commission, Chicago IL.

Maurer, George. 1996. A Better Way to Grow: For More Livable Communities and a Healthier Chesapeake Bay.

Chesapeake Bay Foundation, Annapolis MD.

Schueler, T. 1987. Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs. Metropolitan

Washington Council of Governments. Washington, DC.

Schueler, T. 1997. Comparative Pollutant Removal Capability of Urban BMPs: A Reanalysis. Watershed Protection

Techniques, 2(4): 539-542. Center for Watershed Protection. Ellicott City, MD.

South Carolina Coastal Conservation League (SCCCL). Fall 1995. Getting a Rein on Runoff: How Sprawl and Traditional

Town Compare in SCCCL Land Development Bulletin (Number 7). South Carolina Coastal Conservation League,

Charleston, SC.

205
Predicting Erosion Rates on Construction Sites Using the Universal Soil Loss

Equation in Dane County, Wisconsin

J.D. Balousek, A. Roa-Espinosa, G.D. Bubenzer

Erosion Control Engineer, Dane County Land Conservation Department (LCD), Urban Conservationist, Dane County

LCD, Professor, University of Wisconsin-Madison

Madison, Wisconsin

Tools for Urban Water Resources Management and Protection

Sponsored by Urban Water resource Conference

Northeastern Illinois Planning Commission

The Westin, Michigan Avenue

Chicago, Illinois

February 7 to lo,2000

Abstract

The Universal Soil Loss Equation (USLE) was developed for estimating sheet and rill erosion from agricultural fields

under specific conditions. Parameters used to estimate erosion include rainfall energy, soil erodibility, slope length,

steepness, surface cover, and management practices. Traditionally, urban conservation planners have not used the USLE

for estimating soil loss and evaluating conservation measures and have relied on intuition alone to locate erosion control

practices on constructions sites. The results of this process are often subjective and may vary with the skill of the planner.

A USLE-based equation would provide a valuable, objective method for all planners, regardless of skill, to tailor specific

construction site practices to existing conditions. A method to predict soil loss from construction sites was developed by

adapting existing data for USLE erosion calculations to construction site conditions. In addition, the construction site

procedure was used to create a user-friendly computer-based program to assist planners in developing erosion control

plans. The computer program was distributed to engineers responsible for erosion control planning in Dane County,

Wisconsin. Implementation of the USLE-based equation has proven to be a valuable tool for assessing alternatives for

site management and erosion control. Planners are able to uniformly implement the equation on construction sites

throughout the county, decrease the time necessary to complete a USLE calculation, and reduce human error.

Keywords:

Universal Soil Loss Equation (USLE), urban erosion control.

Background

Soil erosion, detachment of soil particles from the soil surface, results when soil is exposed to the power of rainfall

energy and flowing water. Soil erosion causes a loss of productivity in the land, delivers millions of tons of sediment into

waterways, and provides a substrate for toxic chemicals which are carried into receiving waters. Construction site erosion

has been identified as a significant source of suspended solids in runoff in many parts of the United States (Hagman, et

al., 1980; Yorke and Herb, 1976; Becker, et al., 1974). In the State of Wisconsin, sediment is the largest pollutant by

volume (Wisconsin Department of Natural Resources, 1994). When erosion is compared on a rate basis, construction

site erosion generates more erosion in ashortperiod of time than any other land disturbing activity (Johnson and Juengst,

1997). While it is not possible to urbanize a watershed without exposing soil to erosive forces, it is possible to plan

construction to control the production of sediment through the use of erosion prevention and reduction practices.

The Universal Soil Loss Equation (USLE) (Equation 1) was developed by the United States Department of Agriculture

(USDA) for estimating sheet and rill erosion from agricultural fields under specific conditions (Wischmeier and Smith,

1978). The USLE enables planners to predict the average annual rate of soil erosion for combinations of seeding and

management practices in association with a specified soil type, rainfall pattern, and topography. The equation groups

206
interrelated physical and management parameters influencing erosion rate into six major factors whose site-specific

values can be expressed numerically. More than a half century of erosion research in many states has supplied

information from which the USLE factors were determined.

The Universal Soil Loss Equation.

Where:

A=RxKx(LS)xCxP (Equation 1)

A = average annual soil loss

R = rainfall and runoff factor

K = soil erodibility factor

L = slope length

S = steepness factor

C = cover and management factor

P = support practice factor

The computed soil loss in tons/acre/year.

The rainfall and runoff factor is the number of erosion-index units in an average year’s rain. The erosion index

is the storm energy in hundreds of foot tons times the 30 minute storm intensity.

The soil erodibility factor is the soil loss rate (tons per acre) of a specific soil type and horizon as measured on

a standard plot of land.

The slope/length factor is the ratio of soil loss from the actual land slope length to that from a standard plot (726

feet in length) of land. Slope length is defined as the distance from the point of origin of overland flow to the

point where either the slope gradient decreases enough that deposition begins or runoff water enters a well

defined channel that may be part of a drainage network or a constructed structure.

The slope/steepness factor is the ratio of soil loss from the actual land slope gradient to that from a standard

plot of land (9%).

The cover and management factor is the ratio of soil loss from an area with specified cover and management

to the corresponding loss from a clean-tilled, continuously fallow condition.

The ratio of soil loss with a support practice such as contouring, stripcropping, or implementing terraces

compared to up and down the slope cultivation. The support practice factor does not usually apply to soil loss

on construction sites.

Soil losses computed with the USLE are best available estimates, not absolutes. The USLE will generally be most

accurate for medium-textured soils, slope lengths of less than 400 feet, gradients of 3 to 18%, and consistent seeding

and management systems represented in the USDA erosion studies. The USDA research shows that in comparing actual

soil loss to computed soil loss, 84% of the differences in long-time average soil losses were less than 2 tons/acre/year

(Wischmeier and Smith, 1978). The accuracy of a predicted soil loss depends on how accurately physical and

management conditions on the particular site are described by the parameter values. Large-scale averaging of parameter

values on mixed drainage areas reduces accuracy.

Traditionally, urban conservation planners have not widely used an equation similar to the USLE for estimating soil

loss and evaluating conservation measures. They have relied on intuition alone to locate erosion control practices on

construction sites. A USLE-based equation provides a valuable, objective method for all planners, regardless of skill, to

tailor specific construction site practices to existing conditions. Erosion control is more efficient when it focuses erosion

control practices in areas on the site identified by the USLE as being the most susceptible to erosion.

207
The objectives of this project were to: 1) develop a method to predict soil loss from construction sites by adapting

existing data for USLE erosion estimation to construction site conditions and 2) create a user-friendly computer-based

program to assist planners in developing construction site erosion control plans with the USLE.

Implementation Area

The project was conducted in Dane County, located in south-central Wisconsin. Dane County has extremely diverse

and vast water resources with 475 miles of rivers and streams and 37 lakes, but these resources are threatened by rapid

urban growth. Within the next twenty years, it is conservatively estimated that an additional 72,000 people will live in the

county. Residents recognize how impacts to water quality affect their standard of living, and are interested in protecting

water resources.

Due to the value that the citizens of Dane County place on water quality, a very restrictive erosion control ordinance

was adopted in 1995. Any land disturbance greater than 4000 square feet must comply with the Dane County Erosion

Control Ordinance (Dane County, 1999). As part of this ordinance, applicants must prove that the erosion rate on their

project will not exceed 15 tons per acre over the construction period for non-sensitive areas. In sensitive areas, including

sites adjacent to, or directly draining to, lakes, streams, and wetlands, the soil loss is limited to 7.5 tons per acre over the

construction period. In order to prove the soil loss rate is below the county standard, applicants need to calculate the

USLE for their site from the start of construction until the site is stabilized. The Dane County Land Conservation

Department reviews erosion control plans for accuracy of the plan and compliance with the ordinance.

Met hods

Adapting USLE to construction site conditions

Our first objective was to develop a method of predicting soil loss from erosion on construction sites based on the

guidelines given by the USDA for the USLE. In order to adapt the USLE to urban conditions, each variable in the equation

was examined (see Equation 1).

The rainfall factor, R, is the first factor modified. Published R values represent erosivity during an average year. Most

construction sites do not remain disturbed for exactly one year. In addition, the time of year that the site is open is critical

in determining the amount of rainfall energy that will occur. In the Midwest, over half of this rainfall energy occurs during

July, August, and September. Projects that take place in the summer will experience higher intensity storms than projects

constructed in the winter. For these reasons, the R factor needs to be adapted to the construction schedule of the project

(Table 1).

Table 1. Percent of R occurring after January 1”for Dane County, Wisconsin.

1*

15’”

January February March April May June

0 0 2 4 9 20

0 1 3 6 14 28

1”

151h

July August

39 63

59 72

September October

80 91

87 94

November December

97 99

98 100

Once the percent R is calculated for the interval of time that the land will be open, it is multiplied by the annual R

factor for Dane County (150).

R = (% of R to date) x (Annual R factor)

The soil erodibility factor, K, represents a soil’s ability to resist erosion. The factor is determined by documenting

erosion of a soil in a bare condition on a unit test plot. The higher the erosion rate, the higher the K factor. On construction

sites, the subsoil K factor is often used because the topsoil is usually stripped. Subsoil K factors can be found in USDA

208
Soil Interpretation Records. The soil properties that affect erodibility include: soil structure, soil particle size distribution,

permeability, organic matter content, and iron content.

The slope length/steepness factor, LS, relates the length and steepness of the slope (Equation 2). The rate of erosion

increases exponentially as the length of the slope becomes longer. Erosion rates rise even more drastically as the

steepness of the slope increases. The percent slope is a representative portion of the disturbed area, representing

overland flow, not channel flow. The slope length is measured along the flow path from the top to the bottom of the slope

of the disturbed area.

Formula used to calculate the LS factor.

LS = (L/76.6)“(65.41 Sin26+4.56Sin0+0.065)

(Equation 2)

Where: L = slope length in feet

6 = angle of slope (in degrees)

M = 0.2 for slopes < 1%

M = 0.3 for slopes 1 .O to 3.0%

M = 0.4 for slopes 3.0 to 4.5%

M = 0.5 for slopes > 4.5%

The cover and management factor, C, is based on the type and condition of the cover on the soil surface. In

construction site erosion control, the cover is extremely important. The vegetative cover provides protection from rainfall

impact and runoff water. If the condition of the cover is poor, the C factor will be high. Conversely, when the vegetation

is well established, the erosion and C factor will be reduced. C factors for construction sites can be found in Predicljng

Rainfall Erosion Losses (Wischmeier and Smith, 1978). The C factors for seeding, seeding and mulching, and sod

represent the average cover over the establishment period. Once the site is seeded or sod is installed, a period of sixty

days during the growing season is automatically assumed for cover establishment. If the end of the sixty-day cover

establishment period falls after the recommended seeding dates, the calculation must be carried out to the following

spring to allow for adequate growth.

Commonly Used C Factors: Bare ground 1 .oo

Seeding 0.40

Seeding and Mulching 0.12

Sod 0.01

The support practice factor, P, is not used to calculate soil loss on construction sites.

The product of the R, K, LS, and C factors equals the computed soil loss per acre over the construction period. In

Dane County, if this number is greater than the required standard, the project must reduce erosion below the standard

by using erosion control practices or by changing the management schedule. This assumes that 100% of soil loss is

transported and deposited off-site for relatively small areas of less than 40 acres with no intervening obstructions or

flattening of the land slope.

Developing the Spreadsheet to Calculate the USLE

Implementation of the USLE in erosion control plans was required for all land-disturbing activities greater than 20,000

square feet in Dane County after January, 1995. The calculation of soil loss was difficult for the consulting engineers

responsible for submitting plans. In addition, the USLE calculations were often done incorrectly or the wrong data were

used as inputs. For these reasons, a user-friendly computer-based program was developed to assist erosion control

planners with the USLE calculation. The program uses Microsoft Excel 97*, a spreadsheet program that is commonly

used among the engineering community.

209
The worksheet (Figure 1) uses the following variables and inputs (Table 2) which are either entered by the user or

automatically calculated in the non-shaded rows.

Figure 1. Screen-capture of spreadsheet.

Table 2. Variables used in the spreadsheet.

Column # Variable

1 Land Disturbing Activity

2 Date

3 % R to Date

4 Period % R

5 Annual R Factor

6 Soil Map Unit

7 Soil Erodibility K Factor

8 Slope % S

9 Slope Length L

10 LS Factor

11 Land Cover C Factor

12 Soil Loss

13 Percent Reduction to Meet Ordinance

Type

entered by user

entered by user

automatically calculated

automatically calculated

automatically calculated

entered by user

automatically determined

entered by user

entered by user

automatically calculated

automatically determined

automatically calculated

automatically calculated

Variable/Input Descriptions:

Land- Disturbing Activity

The land-disturbing activity relates to the type of disturbance that is occurring on the ground and must be selected

by using a pull down menu. Activity Inputs:

‘Use of the commercial product name is for the convenience of the reader and does not imply endorsement of the product by either the Dane County Land Conservation

Department or the University of Wisconsin.

210
bare ground

seeding

mulch with seed

sod

end

Date

Usually the initial disturbance and occurs when the ground is left bare due to stripping

vegetation, grading, or other actions that leave the ground devoid of vegetation.

The application of permanent ortemporaryseeding without the use of mulch. Seeding requires

that the user allows 60-days during the growing season for cover establishment.

The application of a minimum of 1.5 tons/acre straw or other comparable mulching. This input

is entered if the seeding and mulching are done at the same time. It is not necessary to also

enter

seeding if this input is used. This input also requires a 60 day cover establishment period

during the growing season.

The installation of sod for cover establishment.

End is a required input at the end of the 60-day cover establishment period. If the site is

stabilized by a method other than vegetative cover, end should also be entered.

The date the planned land disturbing activity begins, e.g. 5/l 5/99. The activity is assumed to continue until the next

activity is entered. When seeding dates are later than the dates recommended for permanent cover establishment, the

end date must be carried out to the next spring, rather than 60 days.

% R to Date

The percentage of the annual R factor from January 1 st to the entered date.

Period % R

The percentage of the annual R factor calculated for the period from one land disturbing activity to the next.

Annual R Factor

The rainfall factor, R, is the number of erosion-index units in a normal year’s rain. The erosion index is a measure

of the erosive force of a specific rainfall. In Dane County, Wisconsin the rainfall factor is 150.

Soil Map Unit

The soil map unit for the predominant soil type in the area of the land disturbing activity.

Soil Erodibility K Factor

The erosiveness factor of the subsoil for the specified soil map unit.

Slope % S

The percentage slope for the representative portion of the disturbed area, representing overland flow and not

channel flow.

Slope Length L

Slope length (in feet) is measured along the overland flow path from the top to the bottom of the slope of the

representative disturbed area.

211
LS Factor

The LS factor is calculated using the equation for LS described previously (see Equation 2).

Land Cover C factor

The cover and management factor is the ratio of soil loss from an area with a specified cover and management

practice to that of a unit plot of bare land. The input for the land disturbing activity corresponds to this factor.

Soil Loss

The predicted value of soil loss (tons/acre) which corresponds to the time period of each land disturbing activity.

This value is calculated using the equation:

A=%RxRxKx(LS)xC

Percent Reduction Required to Meet Ordinance

The percentage value in the total row corresponds to the reduction of soil loss necessary to comply with the Dane

County Erosion Control Ordinance. It is required that the cumulative soil loss rate not exceed 15 tons/acre for nonsensitive areas and 7.5 tons/acre for sites that are located adjacent to or directly drain to sensitive areas.

Typical Spreadsheet Example for Dane County, Wisconsin

Figure 2 shows a sample USLE calculation using the spreadsheet. The assumptions are that construction will begin

on July 17, 1999, and the site will be seeded and mulched on October 31, 1999. The representative pre-existing slope

is 10% over 100 feet and the slope after grading will be 5% over 250 feet. The soil type is Dresden Silt loam (DsC2). The

estimated soil loss rate for this site is 15.9 tons/acre. If this site is located near a sensitive area, the soil loss must be

reduced by 53% to comply with the 7.5 tons/acre standard; on the other hand, if the site was not located near a sensitive

area, the soil loss only needs to be reduced by 6% (15 tons/acre standard).

Universal Soil Loss Equation for Construction Sites

Dane County Land Conservation Department

RW Ddle

717199

Figure 2. Sample USLE calculation.

212
Results and Discussion

There are several advantages to using the adapted USLE for erosion control planning on construction sites. One

advantage is being able to locate areas with the highest erosion rates, which results in more effective erosion control. If

one portion of a construction site is predicted to have a higher erosion rate, more or larger erosion control practices may

be targeted in that area, while less intensive practices may be required elsewhere on the site. The adapted USLE also

facilitates the design of sediment ponds and other erosion control practices. The predicted amount of soil loss exceeding

the standard can be used to calculate the percent reduction necessary to comply with the ordinance.

Another advantage is that the adapted USLE brings in the important element of time. In Wisconsin, the majority

of the year’s rainfall erosion occurs during the summer months. Summer is also the time of year that most construction

is occurring. The USLE accounts for the date and duration the development project occurs and predicts the soil’s

vulnerability to erosion at that time. The USLE may show that staging the construction project will help to reduce the soil

loss on the site.

The spreadsheet program has proven to be a valuable tool for calculating the soil loss. The program has been

distributed for more than a year, free of charge, to the planners and consultants in Dane County. The County’s review

of the calculation in the erosion control plans has become easier and quicker by having a printout that summarizes

the variables used. An advantage of having tables and formulas included in the spreadsheet, is the consistency that is

achieved by everyone using the same parameters. Not only have the calculations of soil loss been more precise and

time schedules more realistic, but planners and consultants have stated that it has saved them time and simplified the

calculation process.

References

Becker, B.C., Nawroki, M.A., and Sitek, G.M., (1974) An Executive Summary of Three EPA Demonstration Programs

in Erosion and Sediment Control, Hittman and Associates, Inc., Columbia, MD.

Dane County Board of Supervisors, Dane County Code of Ordinances (1999), Chapter 14, subchapter II, Erosion Control

System, Dane County Board of Supervisors, Madison, WI.

Hagman, B.S., Konrad, J.G., and Madison, F.W. (1980), Methods for Controlling Erosion and Sedimentation From

Residential Construction Activities, Wisconsin Department of Natural Resources, Madison, WI.

Johnson, C.D. and Juengst, D., (1997), Polluted Urban Runoff: A Source of Concern, University of Wisconsin-Extension,

Madison, WI.

Wischmeier, W.H. and Smith, D.D., (1978), Predicting Rainfall Erosion Losses - A Guide to Conservation Planning,

United States Department of Agriculture, Washington, D.C.

Wisconsin Department of Natural Resources, (1994), The Wisconsin Water Quality Assessment Report to Congress,

PUBL-WR 254-94-REV, Wisconsin Department of Natural Resources, Madison, WI.

Yorke, T.H. and Herb, W.J., (1976) Urban Area Sediment Yield Affects of Construction Site Conditions and Sediment

Control Methods, United States Geological Survey, Parkville, MD.

213
Public Involvement Programs That Support

Water Quality Management

Josephine Powell

Wayne County Department of Environment

Detroit, Michigan

Zachare Ball

Karen Reaume

Environmental Consulting & Technology, Inc.

Detroit, Michigan

The Rouge River, a tributary to the Detroit River, in southeast Michigan, has been documented as a significant source

of pollution to the Great Lakes System. The Rouge River Watershed spans approximately 438 square miles in 48

communities and three counties and is home to over 1.5 million residents. The eastern portion of the watershed contains

much of the older, industrial areas of Detroit and Dearborn. The western and northern portions contains newer suburban

communities and areas under heavy development pressure.

This paper discusses the programs used by the Public Involvement Team of Wayne County’s Rouge River National

Wet Weather Demonstration Project (Rouge Project) to (1) increase watershed awareness of Rouge River Watershed

residents and business owners, (2) educate them about pollution sources to the Rouge River and (3) involve them in

restoration of the Rouge River by showing them that small changes in their daily activities can help improve water quality

and restore the river.

The Rouge Friendly Neighborhood Program was piloted over atwo year period in watershed neighborhoods in three

distinctly different areas of the watershed. All neighborhoods were surveyed to determine the initial level of knowledge

about water quality issues, lawn care maintenance, and pollution prevention practices. Survey results were used to

fashion a neighborhood program for each area. All three neighborhoods received Rouge Friendly brochures, newsletter

articles, and other materials.

The Rouge Friendly Business Program, a companion program to the neighborhood effort, sought to educate small-tomid-sized businesses about how they can positively impact the Rouge River by making small changes to daily business

practices. Since auto-related businesses are very common in the Rouge River Watershed, an automotive services

roundtable was convened. The partners included representatives of automotive service associations, the local chamber

of commerce, and businessmen who met periodically for a year to review draft materials, make suggestions about the

program’s promotion, and to help mold the program before it was implemented. Once implemented, the industry

representatives promoted the program in their publications and recruited businesses to participate in the program.

This paper will describe both of these pollution prevention programs and discuss how the Brightmoor neighborhood

in the Rouge River Watershed was impacted by the Rouge Friendly Neighborhood and the Rouge Friendly Business

Programs.

The Rouge Friendly Neighborhood Program

The Rouge Friendly Neighborhood Program was designed to be carried out by responsible neighborhood

organizations. Preferred prerequisites were:

1. The group participating in the program must represent a defined area or neighborhood.

214
2. The group would participate in the Friends of the Rouge River Watch Program. The river system need not pass

directly through the neighborhood for participation. An assigned segment could be identified for the group by

Friends of the Rouge.

3. The group would participate in the Friends of the Rouge Storm Drain Stenciling Program. The stenciling of storm

drains should include, but is not limited to, all the storm drains within their designated neighborhood or area.

4. The group should actively participate and/or encourage proper household hazardous waste management. This

could occur through:

. Reduced purchasing of hazardous house chemicals

. Proper use of household hazardous chemicals

. Proper disposal of hazardous household chemicals

. Use of less-toxic alternatives to household hazardous chemicals

The group can accomplish this requirement by distributing information concerning proper household hazardous

waste management to their designated neighborhood.

5. The group would facilitate education of residents regarding non-point source pollution. Information would be

provided by the Rouge Project Team for distribution to the designated neighborhoods.

6. Submittal of semi-annual reports discussing the activities that have been taking place could be a requirement to

maintain Rouge Friendly Neighborhood status.

Three Rouge Project area neighborhoods representing different demographics and development history were chosen

as pilots for the Rouge Friendly Neighborhood Program. They were the (1) Brightmoor area of Detroit, an older, developed

area of the watershed along the Main Branch of the Rouge River; (2) Golfview Manor subdivision in Dearborn Heights,

a newer subdivision along the Middle Branch of the Rouge River; and (3) West Bloomfield Place, a subdivision in West

Bloomfield Township, a developing area along the Upper Branch of the Rouge River. These three pilots represented

communities with diverse demographics and concerns.

The Brightmoor neighborhood was a deteriorating area with strong community activism regarding neighborhood

problems and concerns. The neighborhood also showed strong stewardship for the Rouge River, which serves as a

western boundary to the neighborhood and flows through a nearby park. Golfview Manor in Dearborn Heights was a more

upscale, manicured neighborhood that was very active through its subdivision association, but did not have a real

connection to the River. West Bloomfield Place in West Bloomfield Township was an upper income, less urban area

bounded by a wetland.

Meetings were held with a core group of representatives from each neighborhood to garner support from the

neighborhoods’ leadership and to discuss what the program was and what the expected outcomes were.

The residents of all three pilot areas were sent a survey, distributed by mail or door-to-door, to document their

knowledge of Rouge River water quality, storm water issues, and household hazardous waste disposal. In addition,

respondents were asked for demographic information. The survey information was used to determine what the Rouge

Friendly Neighborhood Program should focus on in each particular neighborhood.

Educational materials that had been developed about storm water pollution, household hazardous waste (and its

disposal), and watershed awareness were reviewed by each group. Each core group helped develop the particular

program that would be implemented in their neighborhood, because Rouge Project staff knew that no program would be

a success without the core groups’ support and endorsement. These core group members were relied on to explain the

program at neighborhood meetings.

215
The Rouge Friendly Business Program

The Rouge Friendly Business Program was developed as a partnership between Wayne County, local government,

and the business community to restore and protect the Rouge River. To accomplish this goal, information and assistance

are provided to small business owners to teach them how they can positively affect the water quality of the Rouge River

by changing some of their everyday practices. The education process is not about major contaminants, but those little

things that slip the mind, such as keeping the dumpster lid closed and storing materials under cover. These simple actions

can affect water quality because they stop pollutants from entering the storm system. As an incentive to participate,

Wayne County embraced the concept that businesses in the watershed that demonstrate stewardship and a strong

environmental ethic should be recognized by the community for their voluntary participation. As such, these businesses

should enjoy greater name recognition through the efforts of the local and regional media as well as specific program

materials, such as decals and magnets that identify the business as Rouge Friendly.

The Rouge River Watershed has approximately 42,000 businesses in its 48 communities and three counties. To

design program materials that would have the greatest impact, three criteria were developed to target business types.

They are:

l The business has a high incidence of illicit connections to storm drains

l The business conducts a significant number of pollutant-generating activities outdoors

l The business is found in large numbers in the watershed

Using these criteria, six types of businesses were selected and specific activities identified. They are:

l Vehicle Service Industry

l Food producers, grocers, and eating establishments

l Metal Machining

l Earth Disturbing Construction

l Remodeling and Repair Contractors

l General Business

Pollution control criteria were established for each kind of business. These criteria were used to create a selfassessment form to be used by business owners to evaluate how “Rouge Friendly” their businesses are. Best

Management Practices (BMPs) were also written that correspond to each activity and this information was put into the

booklet along with a self-assessment form for distribution.

Representatives of various trade organizations were invited to participate in a Vehicle Service Industry Roundtable.

The roundtable was asked to review and comment on the educational materials, the self-assessment form, the BMPs,

and the best way to conduct program outreach. Rouge Project staff sought to engage businesses in an ongoing dialogue

to determine what approach would work best, with a secondary goal of determining how to get businesses to participate.

Feedback from this group resulted in a name change from the “Clean Business Program” to the “Rouge Friendly Business

Program.” This was not a quick process, but took approximately six months of meetings to (1) form a Vehicle Service

Industry roundtable, (2) explain the purpose of the Rouge Friendly Business Program, and (3) refine the program and

products. The Rouge Friendly Business Program elements were finalized as follows:

l Self-assessment form and action plan

l Best Management Practices

216
l Site visits by technical staff

l Recognition materials for participating businesses (stickers and magnets)

l Business pledge and newspaper recognition

After these materials were finalized, Wayne County and Rouge Project staff promoted the Rouge Friendly Business

on a pilot basis and recruited businesses through the following mechanisms:

l Business Roundtable contacts

l Letter and telephone contacts

l Door to door contact with businesses

l Contact through homeowner/neighborhood associations

l Integration of Business and Residential Programs

By the end of the pilot period, the Wayne County Department of Environment had recognized 20 businesses as

Rouge Friendly.

The Brightmoor Community Pilot

The Brighmoor area of Detroit was developed in the 1920s as a neighborhood forworking-class families. Most houses

are frame, with the newer areas of the neighborhood (1940s and 1950s) of brick construction. Over the past 15 years,

the Brightmoor area has deteriorated. Its once vibrant business strip is dotted with boarded, vacant buildings, graffiti,

trash, and debris. Whole blocks of residential land are vacant and overgrown and illegal dumping is abundant.

Environmental abuses ranged from a myriad of abandoned vehicles to illegal car repair businesses on residential streets.

The Rouge Friendly Neighborhood Survey (Attachment A), distributed in Brightmoor in 1996, showed that the top two

environmental concerns in the area were illegal dumping and abandoned housing.

Despite these challenges, the Brightmoor neighborhood had two characteristics that made it a viable pilot for the

Rouge-Friendly Programs. One, Eliza Howell Park, located on its western edge, was traversed by two branches of the

Rouge River. Second, Brightmoor had a wealth of grassroots organizations who were working to make the neighborhood

better. Some annually removed log jams and other debris from the Rouge River in Eliza Howell Park during Rouge

Rescue, sponsored by Friends of the Rouge, a grassroots organization serving the whole watershed.

Initial contact was made with the Brightmoor Concerned Citizens and other neighborhood representatives in January,

1996. The group agreed that they would like to participate as a Rouge Friendly Neighborhood pilot. A month later, the

same group met again with Rouge Project staff. This time, city parks staff were present. They were told about the

possibility of grant funding for storm water projects by the Rouge Project. The group brainstormed the kinds of things

they would like to see happen at the park, which had suffered from spotty maintenance. They agreed that they would

like to see wildflowers and prairie grass planted, nature trails restored, and a community garden created. The parks

department later applied for and was awarded a $180,000 grant to plant wildflowers and prairie grasses and to install

nature trails in the lower end of the park, near the Rouge River.

The next step in the program was to survey residents about their knowledge of pollution entering the river and

household hazardous waste disposal, their neighborhood environmental concerns, and demographic information. The

survey was created with input by the core neighborhood group. The major data extracted from the survey were:

. 78% thought the Rouge River was polluted or very polluted, and 20% thought the river was getting worse.

. 38% did not know that the storm drains lead directly to the Rouge River. However, 56% understood that sanitary

sewers go to the wastewater treatment plant.

217
. 18% correctly answered that industry pollutes the Rouge River the least and 66% thought stormwater pollutes the

least.

. 87% maintained their own lawn. There was an even distribution among those who never fertilize their lawns and

those who fertilize l-2 times per year.

. 75% did not change their own motor oil.

l 80% took their cars to a car wash instead of washing it themselves.

l 92% claimed indicated that they know what household hazardous waste is, and 73% correctly identified motor oil

as a household hazardous waste. However, 54% did not properly dispose of their wastes.

. 83% said they were committed/very committed to make small changes to prevent pollution.

Following are neighborhood issues, in order of importance:

1. Abandoned buildlings

2. Illegal dumping

3. Household hazardous material disposal

4. Infrequency of street sweeping and storm drain cleaning

5. Recycling

6. Do-it-yourself car repair/illegal car lots on residential streets

7. Overuse of garden/lawn pesticides

8. Overuse of fertilizer

9. Composting

Wayne County Rouge Project staff, Friends of the Rouge, and Brightmoor Concerned Citizens leadership made a

presentation, including survey results, to the general membership in May, 1996. The general membership was

enthusiastic about the program. The annual Rouge Rescue held in Eliza Howell Park on June 1,1996, was expanded

to include other activities, including storm drain stenciling, a tour of a newly constructed combined sewer overflow basin,

and children’s games.

Subsequent meetings with the Brightmoor group were used to brainstorm what the specific program elements should

be and what outcomes were expected. The following elements were supported by the core group:

l Urban gardens on vacant lots

l Composting education

l Attempting to get rid of the massive log jam at the confluence of the Upper and Main Rouge River in Eliza Howell

Park

. A tour of the area for the Detroit Environmental Court judge

l Lawn signs that read “I support the Rouge Friendly Neighborhood Program”

l Early recognition of well-maintained lawns and gardens; Brightmoor’s “Resident of the Month”

218
l A Brightmoor Rouge-Friendly Business Program

l A renters’ workshop to educate tenants about their rights and responsibilities and the responsibilities of landlords

l Educational materials in the various neighborhood newsletters

All of the activities were implemented except the lawn signs, the recognition of well-maintained gardens, and the

renters’workshop. By the fall of 1996, the focus had shifted to conducting a monthly combined resident/business owners’

meeting to include businesses, which were primarily vehicle service oriented, into the Rouge-Friendly initiative.

Results and Outcomes

Rouge-Friendly Neighborhood Program: Because of the enthusiasm and commitment of Brightmoor residents and

business owners, many activities were conducted. They were:

. Thousands of educational brochures and children’s materials were distributed in community centers, businesses,

schools, and newsletters.

. A local business owner successfully sued a public utility that was pumping hundreds of gallons of polluted

stormwater into the Rouge River.

l The local community organization not only enthusiastically participated in the annual Rouge Rescue event, but

conducted another such event on its own.

l Through a partnership with the city parks department, the Greening of Detroit, and the Brightmoor Concerned

Citizens, 100 trees were planted in Eliza Howell park by 200 local elementary school students.

l City officials agreed to conduct an environmental ticket blitz in the neighborhood, which resulted in the following

tickets being written: 179 parking tickets, 71 abandoned cars tagged for removal, 8 stolen cars being towed, 15

public works tickets for bulk garbage being put at the curb too early, 2 environmental protection tickets, and 47

tickets for inoperable vehicles.

l A monthly meeting that included neighborhood residents, business owners, non-profit organizations, city officials

(including police commanders), and county officials focused on environmental issues.

Rouge-Friendly Business Program: While many outstanding initiatives were accomplished by meeting with the

Brightmoor stakeholders monthly, only one Brightmoor business was recognized as Rouge Friendly after ten months of

monthly meetings. The meetings were well-attended and business owners felt comfortable discussing their environmental

concerns. In June, of 1997, the approach for recruiting Brightmoor businesses as Rouge Friendly was changed. A

community leader was paired with a technical staff member and they proceeded to visit neighborhood businesses. They

visited 14 neighborhood businesses several times over a two-month period. Information about the program was left with

the business owners, as well as an offer from the technical staff member to help the business owner with the selfassessment form. Through this effort, Wayne County recognized six additional Brightmoor businesses as RougeFriendly. This was a successful (43% participation), but labor intensive, method of recruiting businesses.

219
ATTACHMENT A

ME ROUGE RIVER 

A WORLD CLASS EFFORT

FQOJECT pollution

BRWGING OUR RIVERBACKTOLIFE Start today by filling out this questionnaire.

We are working with the Rouge River National Wet Weather Demonstration Proiect to make our

subdivision a more attractive place to live. We have been chosen as one of three pilot neighborhoods in the

Rouge River Watersheds to participate in a pollution prevention program that may be used as a model for other

urban watersheds across the country. In order to design a program that best fits our needs, we need you to

answer a few questions. The following survey is voluntary and confidentiaf. Use the enclosed pre-stamped

envelope to return the questionnaire by April 22, 1996.

6. How do you maintain your lawn?

7. How often is your lawn fertilized?

a. Where do you change the oil

in your car?

9. Do you usually wash your car

or take it to a car wash?

10. If you change your oil at home,

how do you dispose of it?

11. Do you know what household

hazardous materials are?

12. Which of the following is a

household hazardous material?

1.

2.

3.

4.

5.

Very polluted Somewhat polluted Not polluted

Do you think the Rouge River ls polluted? 5 4 3 2 1

Getting cleaner Stayihg the same Getting worse

Do you think the Rouge River Is getting 5 4 3 2 1

cleaner,staying the same, or getting worse?

Where does water go when it enters an q To a storage tank under the ground

outside storm drain in your neighborhood? 0 To the Rouge River

0 To the waste water treatment plant

0 Don’t know

Where does water go when it

is flushed down the toilet or sink?

l-~ To a storage tank under the ground

0 To the Ftouge River

q To the waste water treatment plant

0 Don’t know

What pollutes the Rouge River the LEAST? q Combined sewer overflows

(a mixture of sewage and sfonnwater that

flows into the river when it rains.)

0 Stormwater (water that runs ofi

the grvund and enfers the river)

q Industry

q Paid professional company

0 Paid neighbor

q Someone in the household maintains it

q 1 to2timesperyear

u 3 to 4 times per year

0 More than 4 times per year

0 Never

l-~ Auto Repair Shop/Quick Oil Chnage

q Yard 0 Street q Driveway

0 Wash it myself

q Carwash

0 In the garbage 0 On the ground

0 In the sewer 0 Take to facility that

q Don’t know accepts used oil

[7 Yes

uNo .

q Baklqg soda 0 Lemon oil

[7 Motor Oil j-~ Vinegar

220
13. How do you dispose of your q Put it in the trash q Dump it down the sink

household’s hazardous materials? f-~ Dump it on the ground [J Don’t know

0 Take it to a Household Hazardous Drop-off Area

14. Indicate whether the following environmental issues are

very important, important, or not important to your subdivision.

Overuse of fertilizer

Composting

Abandoned buildings

Frequency of street sweeping

and storm drain cieaning

Overuse of garden/lawn pesticides

Recycling

Household hazardous waste

Illegal dumping

Do-it-yourself car repair / Illegal

car lots on residential streets

Other (specify: )

15.

16.

17.

18.

19.

20.

21.

Very important

5 4

5 4

5 4

5 4

5 4

5 4

i

4

4

5 4

5 4

tmportant

3

3

3

3

Not important

1

1

1

1

You can make small changes to prevent pollution (i.e. the type of fertilizer you purchase, how you dispose of your motor oil, etc.). What is your level of commitment to make these changes?

Very committed Somewhat committed Not interested

How many people, including yourself,

live at this address?

How many of these are children?

How many pets do you own?

What is your gender?

What is your age group?

What was the last grade

you completed in school?

4 3 2 1

1 cl5

23 z iore than 6

4

0 03

1 04

2 q More than 4

01 00:

2 q More than 4

Female •: Male

Under 18 years 0 46-60 years

13-30 years q Above 60 years

3 145 years

Some high school

Completed high school

Post-high school training

Some college

Completed college

Graduate or professional school

Thank you f-or doing your part in cleaning up Gr subdiision! Remember, return the questionnaire

in the pre-paid envelope by April 22, 1996.

Any questions should go to John or Shelley Mlynarczyk at 533-3453

221
The Water-Wise Gardener Program:

Teaching Nutrient Management to Homeowners

Marc T. Aveni

Virginia Cooperative Extension

Manassas, Virginia

Introduction

The Water-wise Gardener program was developed by Virginia Cooperative Extension (VCE) seven years ago with

funding from the Cooperative State Research, Education, and Extension Service (CSREES) of the U.S. Department of

Agriculture (USDA). It is an educational program aimed at reducing non-point source pollution from suburban residential

areas. The educational focus is upon nutrients, especially nitrogen and phosphorus from lawn fertilizer over-application

or misuse. The program seeks to reduce such nutrient pollution to Virginia waterways, and eventually the Chesapeake

Bay, through the recruitment of homeowner participants from impaired watersheds. Participating homeowners attend

educational seminars on lawn best management practices, are partnered with a Master Gardener volunteer, and are

expected to keep accurate records and implement recommended practices. The program, which is currently being

implemented in 12 urban/suburban Virginia counties, is supported by a combination of local county funds, grants from

the Virginia Water Quality Improvement Act, and funds from USDA. Cooperative Extension Units in North and South

Carolina have replicated the program.

How the Program Works

The Water-wise Gardener program begins by recruiting homeowners from watersheds with impaired streams or

other identified problems to participate in a year-long lawn care educational program. The most successful recruitment

method to-date has been to conduct a “reverse search” on the Internet by street name. Once names and addresses are

identified, a recruitment letter is sent personalized for the watershed; e.g., “Dear Resident of the Bull Run Watershed.”

The letter invites the homeowner to participate in the program and lists the benefits of participation, such as free

seasonal seminars with regional experts, visits from a Master Gardener (volunteers trained by VCE in various aspects

of horticulture), a free soil test, and Virginia Tech publications. In order to be enrolled in the program, the homeowners

must return a completed pre-survey and a signed agreement form that details their obligation to the program. The presurvey asks questions about their lawn care practices and attitudes before program involvement, as well as demographic

information such as race, gender, income, and education levels. A stamped, self-addressed envelope is included for

ease of return. For every 100 letters sent out, between 20-30 are typically returned. A simple database program keeps

track of participants and their lawn care data. A reporting system on the Virginia Tech lntranet is currently being

designed to record this information on a statewide basis by hydrologic unit.

Once enrolled, participants are assigned a personal Master Gardener. The Master Gardener schedules a visit with

the homeowner to discuss his or her lawn. All Master Gardeners are instructed to stay outside on the lawn and not to go

inside anyone’s home. Some choose to bring along a spouse, friend, or another Master Gardener. At this visit, the

Master Gardener works with the homeowner to correctly measure the square footage of lawn area, determine the type

and variety of grass, collect a soil sample, and ascertain previous fertilization practices and amounts previously applied,

if known. This information forms the basis of a personalized lawn care plan for the homeowner. Master Gardeners also

answer other questions the participant may have; common questions include weed and pest identification, what plant

grows best where, and why certain plants are not thriving. The Master Gardener leaves a business card with a phone

number or e-mail where he or she can be reached for further questions throughout the program year. All Master

Gardeners receive 50 hours of classroom training as well as supplemental field training before being assigned to

homeowners. Typically, a Master Gardener will be assigned to between 5-l 0 homeowners.

222
In addition to the one-on-one visits from Master Gardeners, homeowners attend seasonal seminars on timely topics

of interest to those with lawns. In Northern Virginia, where cool-season grasses like Fescue and Bluegrass predominate,

fall topics include soil testing, fertilization, core aeration, and over seeding. Spring topics include mowing and pruning,

integrated pest management, and proper watering and planting. Popular locations for seminars include parks with

covered pavilions, school auditoriums, county buildings, and libraries. Any easily accessible public location large enough

to hold 50 to 100 people comfortably, and accessible to wheel chairs, will work. If held inside, cold temperatures, rain,

or wind are not a problem; however, an outside area for demonstration purposes is essential. State and regional

Cooperative Extension experts are recruited for the seminars to answer questions. Master Gardeners are also present,

with various displays, to answer questions and to meet with their assigned participants.

A professional-quality newsletter is sent to all participants approximately six times per year. A grant-paid editor

solicits articles that reinforce or complement topics taught at the seminars. Articles on various aspects of watershed

management are also introduced. The newsletter is made available electronically to other Extension Agents for editing

and reproduction elsewhere.

After participants have attended fall and spring seminars, they are visited again by their Master Gardener to collect

final lawn data and conduct a post-survey of practices and attitudes. The most important piece of data collected is the

amount of fertilizer now being applied. Square footage of turf can be re-checked, if needed, and questions answered.

The homeowner may chose to participate again the following year, or to offer their lawn as a demonstration lawn,

and erect a sign in their yard to promote the program in the community. The post-surveys and data sheets are collected

from all participants annually. Results are compiled and analyzed by a grant-paid technician and a final report generated

for each Cooperative Extension unit as well as an overall report for statewide efforts.

Results

Data for the period March 1998 to June 1999 for the Virginia counties of Arlington, Loudoun, and Prince William

shows 326 individual homeowner participants. These 326 homeowners managed 57.1 acres of turf in 11 different

hydrologic units in the Northern Virginia area. Between 100-200 additional individuals attended seminars but did not

participate in the pre- and post-survey and data collection.

Accurate information on amounts of nitrogen and phosphorus applied by participants before program involvement

is difficult to get. Most did not remember how much fertilizer they had applied in the previous year. Many stated the

reason they joined the program was in order to understand how much fertilizer to apply. A total of 72 participants

reported pre-program fertilizer application of 1,062 pounds of nitrogen. The same 72 participants reported 762 pounds

of nitrogen applied after program involvement, or a reduction of 300 pounds. Information on pre- and post-phosphorus

was not collected.

Pre-surveys indicated that only 12% of all participants had soil tested for their lawns prior to applying fertilizer.

Homeowners not testing soil are more likely to apply excess fertilizer. For this reason, Virginia Tech recommends soil

testing as a nutrient management practice for home lawns. Post surveys show 95% of participants returning surveys

tested soils after program involvement. Another important nutrient management practice for homeowners with coolseason turf is to fertilize in the fall, when uptake by roots occurs best. Pre-surveys indicated that only 32% were fertilizing

at this time of year, while post surveys indicated that 64% were fertilizing in the fall. Similar increases were also observed

for recommended practices such as aeration (from 34% to 83%), and over-seeding (from 35% to 76%). An increase in

the number of participants not watering the lawn at all in the summer also increased (from 18% to 44%) (Figure 1).

Demographics from the program indicate that 72% of participants were male and 28% female. Participants were

overwhelmingly white (89%); followed by black (7%), Asian (4%), and Hispanic (1%). The majority (42%) had a four-year

college degree and a gross family income of over $70,000 a year (54%). More than one-third of the lawns were between

5,000 and 10,000 square feet (35%).

223
W Pre-program III Post-program

Figure 1. Pre and Post Program Practice Adoption

Figure 1. Pre and post program practice adoption.

Conclusions and Lessons Learned

The Water-wise Gardener Program was successful at reaching the intended audience and achieving adoption of

nutrient management practices. Based on the success of the program, it appears that suburban homeowners can be

recruited to maintain their lawns according to recommended practices. Homeowners are willing, with the help of Master

Gardener volunteers in some cases, to keep records on their nutrient use as a part of program participation. Although

326 individuals and 57 acres of turf may seem low for an area like Northern Virginia, it is significant for a populace that

does not traditionally participate in water quality educational programs. Considering that most lawns in suburban

subdivisions have a turf area of around 5,000 square feet, clearly many individuals will need to be enrolled to reach

meaningful numbers.

The study showed that it is difficult to obtain information on pre-program nutrient use for most participants. Most

homeowners cannot provide accurate nutrient use data from the previous 6-12 months. They simply do not remember

how much nitrogen and phosphorous was in the fertilizer bag applied last spring or fall. However, after program

involvement, they do appear to understand how much nitrogen they applied and the square footage of their turf. From

a water quality public policy perspective, it may be preferable to record nutrient use after program involvement and

consider participants’ turf square footage as the urban nutrient management measurement. In this way, the focus could

be upon recruiting more and more individuals to participate in nutrient management educational programs like the Waterwise Gardener, thus increasing the number of acres addressed by urban nutrient management efforts. Such an

approach could easily be integrated into local Geographic Information Systems, providing localities a simple method of

accounting for and reporting on urban nutrient management. Localities interested in a program like the Water-wise

Gardener should contact their local Cooperative Extension office to see if a similar project is already occurring or could

be developed. As this program is being continued and expanded in the 1999-2001 time frame, the opportunity to better

define what is realistic as an urban nutrient management measurement for homeowners will hopefully occur.

224
Chicago Wilderness; Toward an Urban Conservation Culture

John D. Rogner

U.S. Fish and Wildlife Service

Barrington, IL 60010

Chicago Wilderness - Origin and Purpose

We in the Chicago conservation community have been using the word “wilderness” in a highly unconventional context

since 1996. We have coined the term “Chicago Wilderness” to refer to the rich biodiversity which resides in and around

this huge, sprawling metropolitan area, extending from southeast Wisconsin, through the six-county metropolitan area

in Illinois, and around Lake Michigan to northwest Indiana. This is a region which most people think of as anything but

“untrammeled by man, where man is a visitor who does not remain,” in the words of the Wilderness Act, which has

defined our modern concept of wilderness.

This is an area that is associated with--indeed, defined by--humans and their cultural footprint. Although the

“wilderness” is scattered throughout the region, mostly in parcels that would be considered slivers of land by conventional

wilderness standards, it totals over 200,000 acres of land protected within a complex of national tallgrass prairie, national

lakeshore, county forest preserves, city and township parks, and similar preserved public lands. Its protected lands and

waters range from half-acre remnants to the 15,000-acre Midewin National Tallgrass Prairie,

Within this system of preserves can be found some of the largest and best woodlands, wetlands, and prairies in the

Midwest. These lands are set in a much larger matrix of public and private, developed and undeveloped lands that

support nature and the region’s 8 million people.

We have called these lands “wilderness,“in part to draw the attention of people who are focused on Chicago’s cultural

attractions to the existence of these lands in their own metropolis, and in part to deliberately blur the distinction, or

conversely, emphasize the connections between formal wilderness in remote and inaccessible places and wild lands in

the places where people live and work. The biotic connections exist on the land, and they ought to exist in people’s

minds, as well.

The boundaries of the Chicago Wilderness region do, in fact, capture a spectacular concentration of rare ecosystem

types. These ecosystems harbor a high diversity of species, including a large number of those listed as threatened or

endangered in the states of Illinois, Indiana, and Wisconsin. Outside of the metropolitan area, particularly in rural Indiana

and Illinois, diversity decreases sharply as agriculture dominates the landscape.

“Chicago Wilderness”is also the name we have given the collaboration of over 90 organizations in the Chicago region

that have banded together to better protect, restore, celebrate, promote, and publicize our rich biodiversity. An

unfortunate and perhaps somewhat inevitable consequence of urban life is a detachment from the land; thus, a principal

goal of the partnership is to reconnect a landless urban population, in Aldo Leopold’s words, to the “raw material out of

which we have hammered that artifact called civilization.”

Despite the richness of nature and opportunity for conservation in the region, evidence suggests the Chicago region

is experiencing a decline in native species and communities. Prior to protection, much of the region’s current base of

protected land was subject to agriculture, drainage, and other human influences which reduced or eliminated native plant

and animal communities. These areas are often fragmented and isolated from healthy lands which could otherwise serve

as immigration sources for native species.

225
Small fragments are also subject to influences beyond their boundaries, such as urban runoff. Keystone species like

wolves and mountain lions, predators which formerly kept prey species like whitetailed deer in check, have been

eliminated, and deer now threaten to destroy some of our finest lands through overbrowsing. Many of our protected sites

are too small to sustain populations of area-sensitive species, or to retain their full complement of species in the face of

random population processes like immigration and emigration. Exotic plant and animal species pose major threats to

nearly all of our native communities. Landscape level processes, like fire, that shaped the fundamental character of our

ecosystems do not occur with the frequency or to the extent they once did, resulting in shifts in community composition

that usually result in a decline in biodiversity.

Chicago area residents are the beneficiaries of farsighted leaders early in the 20th century who established a tradition

of setting aside natural land in the urban matrix for the public good, a tradition that our forest preserve districts continue

today. The early model was not based on sophisticated concepts of biodiversity conservation, or of ecological processes,

but on the museum approach of setting nature aside and not meddling. We now are the beneficiaries of the science of

ecology, which begins to tell us how the land mechanism is constructed and how it operates. It is dynamic, not static,

and changes occur when landscape processes are interrupted. The science of ecology also reinforces the connections

between humans and the rest of nature.

This allows us to reexamine the old model of setting nature aside and leaving it alone. That removes the most

immediate threat of development, but it does not address the aforementioned degenerative loss of biodiversity due to

fragmentation and alteration of landscape processes. These processes clearly must be reintroduced into our preserves

if biodiversity is to be preserved or restored. Prescribed fire must be intelligently applied, invasive species must be

controlled, plant and animal species must be reintroduced where they have been eliminated, hydrology must be restored

where altered, and science must be improved where our understanding of ecosystem processes is deficient. Perhaps

most fundamentally, the people who must support the greatly increased levels of land management and research

necessary to restore and maintain our public lands in a healthy condition must have a basic understanding of land health

and the value system to commit public resources toward attaining it. Chicago Wilderness, the coalition, is committed to

working on all of these fronts.

Quite understandably, the Chicago region’s system of public lands was, and perhaps still is, the core of Chicago

Wilderness, the initiative. It is what members rallied around during the coalition’s formation in 1996. But the vision quickly

expanded beyond public lands, for two reasons.

First, our public lands do not exist in isolation. They are part of a much larger land base, and the protected 200,000

acres are affected by what happens on the remaining 6 million acres of the Chicago metropolitan land area. The

preserves form the core, but they cannot preserve all the biological parts by themselves since much biodiversity resides

on private unprotected land and because they are subject to outside influences.

Biodiversity considerations need to infuse all of the region’s land use decisions much more extensively that they do

now. Private lands work either in harmony or discordantly with our network of preserves. The link between the two is most

apparent in the case of wetland or aquatic habitats, which in many cases are sustained or impacted by runoff from distant

areas. Streams, rivers, lakes, and wetlands defy the “protect by fencing” approach. Overall watershed characteristics

determine aquatic and wetland habitat quality quite independently of whether the habitat is in a formal preserve or not.

Second, many high-quality, biologically rich pieces of nature persist outside of our preserve system and are

threatened by development, along with other stresses like lackof management. Identifying these biologically important

areas within proposed developments, redflagging them, designing development with their sustainability in mind, and doing

all this with equity for the landowner, is one of our greatest challenges. Nature in the places where we live contributes

so much to quality of life, yet maintaining it through the development process resists standard regulatory approaches.

There are questions now asked routinely in the subdivision design process: does the plan conform to drainage code, are

storm water basins sized properly, is it consistent with surrounding development, does it have proper standards of

landscaping? A standard question should be: does it leave the land biologically richer or poorer? We are not yet routinely

asking this question, although there are development approaches available that can allow us to answer this question

affirmatively.

226
This question could properly be asked for aesthetic reasons alone, but there are practical reasons for doing so.

Native landscapes hold enormous potential for managing storm water and preventing flooding. They hold enormous

potential for cleaning up surface waters so that urban waters become fishable and swimmable, instead of the

neighborhood joke or eyesore. Finding and applying the template for development that preserves and restores biological

diversity, and which serves both aesthetic and utilitarian purposes, is one of the objectives of Chicago Wilderness.

Chicago Wilderness - Structure and Function

Chicago Wilderness formally began as an initiative with the signing of a memorandum of understanding (MOU) by

34 founding members. Members included landowners and land managers; local, state, and federal agencies; centers for

research and education; and conservation organizations, among others. These institutions pooled their resources and

strengths to form the Chicago Region Biodiversity Council, which has grown to include nearly 100 members.

By signing the MOU, the members of this innovative partnership have pledged a commitment to the protection,

restoration, and management of biodiversity in the Chicago region. Four teams focus on central lines of action: science,

land management, policy and strategy, and education and communication. The teams attract the participation of many

non-member institutions, which adds to the scope and strength of the coalition. Chairs of the teams and other member

organization staff form the nucleus of a coordinating group that develops central strategies and maintains momentum.

A steering committee of executives oversees the direction of the overall initiatives. Despite this organizational structure,

Chicago Wilderness has not become legally incorporated under state law, but remains a loose partnership bound by

common goals and objectives.

The potential for Chicago Wilderness to serve as a model for urban conservation attracted the early attention of

several federal agencies, including the U.S. Forest Service, U.S. Fish and Wildlife Service, and U.S. Environmental

Protection Agency, who have provided significant operating grants. State and private grants have supplemented federal

dollars. Direct grants have totaled over 4 million dollars since 1996. This total does not include members’ matching funds

or funds attracted by members for projects catalyzed, but not directly supported by, Chicago Wilderness.

Chicago Wilderness Accomplishments

The Chicago Region Biodiversity Council funds projects on an annual cycle. The Council’s four teams set priorities

for these projects; core staff ensure broad participation from team members. Reviewed and approved by a proposals

committee, funded projects result from collaboration between member institutions and address critical conservation needs

in the region. Since its launch in April 1996, Chicago Wilderness has funded over 130 collaborative projects. In addition

to projects funded directly by the Council, the work of our individual member organizations in their own initiatives is central

to the success of Chicago Wilderness. Projects completed or underway fall into six categories: characterization and

information management; ecological inventory and monitoring; ecological restoration; planning and policy; education,

outreach, and public participation; and communications and publications.

Individual projects have included a NASA-supported land cover mapping project; development of models of presettlement savannas, woodlands, and forests to guide restoration; assessment of restoration effects on bird communities;

a vegetation monitoring workshop; assessment of garlic mustard impacts on native woodland ground flora; development

of model restoration interpretive programs; a biodiversity educators workshop; and creation of a Chicago Wilderness Atlas

of Biodiversity. An early pilot project supported by Chicago Wilderness was the launching of Chicago Wilderness

magazine, a glossy, popular publication on nature in the Chicago area which since has been incorporated as a 501 (c)(3)

and has over 7,000 paid subscribers.

Chicago Wilderness Biodiversity Recovery Plan

In 1909, the Commercial Club of Chicago released the “Burnham Plan,” a landmark of urban planning that proposed,

among other things, a network of public parklands to be set aside for nature and passive recreation. This led to the

legislative establishment of a system of such publicly owned preserves for the Chicago region which has continually

expanded, and now forms the core of the protected lands that currently comprise Chicago Wilderness.

227
The Biodiversity Recovery Plan, completed in late 1999, takes the open space component of the Burnham Plan to

the next step by creating a vision of sustainability, not only for the core of protected land, but for all of nature and its

human inhabitants in the urban area. The recovery plan is a comprehensive statement of what Chicago Wilderness is

about, and it is clearly the most ambitious and significant accomplishment of the coalition to date.

This plan is the result of three years of assessment and planning by representatives of the Chicago Region

Biodiversity Council. The plan identifies the ecological communities of the greater Chicago region, assesses their

condition, identifies major factors affecting them, and provides recommendations for actions needed to restore and protect

them into the future in a sustainable condition. In short, the recovery plan outlines the steps necessary to achieve the

overall goal of the Chicago Wilderness collaboration, which is to protect the natural communities of the Chicago Region

and to restore them to long-term viability, in order to enrich the quality of life of its citizens and to contribute to the

preservation of global biodiversity.

To achieve this goal, the recovery plan identifies the following objectives: 1) involve the citizens, organizations, and

agencies of the region in efforts to conserve biodiversity; 2) improve the scientific basis of ecological management; 3)

protect globally and regionally important natural communities; 4) restore natural communities to ecological health; 5)

manage natural communities to sustain native biodiversity; 6) develop citizen awareness and understanding of local

biodiversity to ensure support and participation; 7) foster a sustainable relationship between society and nature in the

region; and 8) enrich the quality of the lives of the region’s citizens.

The plan has many recommendations, some specific and some general, and identifies roles and specific actions for

Chicago Wilderness members and the greater public that must be engaged to help implement the plan. The plan’s

intended intended audiences include the many staff members and general members of Chicago Wilderness institutions,

publicagencydecision-makers, large landowners, and all concerned and active citizens whovote and otherwise influence

biodiversity conservation in the region.

The recovery plan is both a plan and a process guided by its many sponsors. It is intended as a living document that

will continue to evolve as new ideas and information arise. It is intended to complement the many other planning efforts

completed or underway in the Chicago metropolitan area that are guiding the region to a better and more productive

future. Its ultimate success probably rests on its successful integration into a broader, mainstream regional planning

framework that has economic, cultural, social, and environmental components.

Strategic Visioning

After the second year of operation, the Biodiversity Council saw the opportunity to step back and evaluate the

structure and function of the coalition during the first two years, consider expectations of members at the outset and

evaluate to what extent they were met, and reprioritize its work for the next two years. This process consisted of

development of a member questionnaire, convening of a focus group representing a cross-section of members, and a

weekend retreat by Chicago Wilderness Steering Committee members and other leaders. It culminated with the

development of six priority functions for the next two years, and associated budget requirements.

Some of these functions represent an intensification and refinement of activities the Council is already involved in;

in other cases, they represent new endeavors. They include 1)facilitate networking among Chicago Wilderness members,

including new orientation materials, workshops, symposia, and lectures; 2) establish an integrated information

clearinghouse, including the development of regionwide resource databases, enhancement of the existing web site, and

development of more communication resources; 3) increase publicity and outreach to broader audiences; 4) influence

key actors outside Chicago Wilderness, including the establishment of a Conservation Policy Committee to develop

position statements on regional issues; 5) develop and implement a funding strategy, focusing on large grants from

foundations; and 6) implement, promote, and monitor the Recovery Plan.

228
The Urban Conservation Culture

Conservation efforts in urban areas are often frustrated by the complexity of land use issues, countless players,

tangled politics, ecologically wrecked land, and a public dispossessed of nature. Yet it is crucial that we focus on urban

areas because of the strong political forces concentrated in urban centers that need to be engaged in national

conservation decision-making, and because there is no other way to engage the great majority of people other than to

take the messages to them. Moreover, urban residents are still plain members of Leopold’s land community, regardless

of how obscure the connections, and these connections are best illustrated in the places where they live. Fortunately,

the Chicago region has an added bonus of harboring world-class biodiversity, which creates a local, immediately

compelling reason for public involvement and action.

Some writers have argued that the American ideal of wilderness has tended to shape our dominant view of nature

itself as a place that can only be corrupted by human influence. In urban areas, this has created an assumption that “real”

nature cannot exist in these places and it tends to absolve urban residents from local responsibility. Thus, it seems that

Chicagoans are much more aware of the plight of Brazilian rain forests that they are of the plight of oak savannas, a

globally rare community, in local forest preserves. In remote areas, the standard approach has been to specifically

designate areas as wilderness, and then maintain as complete a separation between people and these areas as possible.

Chicago Wilderness proposes to redefine wilderness to include local plant and animal communities, which can only be

sustained through direct, creative human intervention. A premise of the recovery plan is that if we do not adequately enlist

people to directly or indirectly support management and restoration of our lands, they will not become or remain healthy.

It is appropriate to recognize that humans in the Midwest alwayshaveinfluenced landscapes, for better or worse, and

that people can be a positive force in maintaining ecosystem health. It may be that by calling a 200-acre patch of prairie

in a sea of development wilderness, and by involving people in its stewardship, we can promote a correct sense of unity

between the places that we live and remote places we may never see except as pictures on calendars. Restoration and

stewardship can be the antidote to dualistic thinking. Remote wilderness and Chicago Wilderness can perhaps then be

seen as simply examples of nature, as part of a single system that includes people.

From a relatively straightforward beginning that focused on public land management issues, this, I think, has become

the broader goal of Chicago Wilderness--to reconnect people with nature and to make a societal commitment to sustain

and nurture nature--for utility, for aesthetics, for spirituality, for all of the equally valid reasons for doing it, on all of our

urban lands and in all of our land-use decisions. It begins with a process of educating the public about the natural wealth

in the Chicago area, and hopefully ends sometime in the future with the development of an urban conservation culture

of concern and personal responsibility for the health of all of our lands, both public and private.

229
A Survey of Resident Nutrient Behavior in the

Chesapeake Bay Watershed

Chris Swann

Center for Watershed Protection

Ellicott City, Maryland

In recent years a handful of communities have attempted to craft education programs to influence our watershed

behaviors. These initial efforts have gone by a confusing assortment of names, such as public outreach, source control,

watershed awareness, pollution prevention, citizen involvement, and stewardship, but they all have a common theme --

educating residents on how to live within their watershed.

Many communities will need to develop watershed education programs in the coming years to comply with pending

EPA municipal stormwater NPDES regulations. Indeed, half of the six minimum management measures prescribed under

these regulations directly deal with watershed education - pollution prevention, public outreach and public involvement.

Yet, many communities have no idea what kind of message to send, or what media to use.

In the following presentation, we review the prospects for changing our behaviors to better protect watersheds. We

begin by outlining some of the daunting challenges that face educators who seek to influence deeply rooted public

attitudes. Next, we profile research on the outreach techniques that appear most effective in influencing watershed

behavior. Special emphasis is placed on media campaignsand intensive training programs. Lastly, recommendations are

made to enhance the effectiveness of watershed education programs.

Challenges in Watershed Education

Watershed managers face several daunting challenges when they attempt to influence watershed behaviors. Some

of those challenges include:

A lot of minds to change

The most pressing challenge is that there are simply a lot of minds to change. Some notion of the selling job at hand

can be grasped from Table 1, which contains provisional, but conservative, estimates of potential residential “polluters”

in the United States by various categories. It is clear that we are attempting to change deeply rooted attitudes held by

millions of people. While most people profess to support the environment, only a fraction actually practice much of a

watershed ethic on the small parcels of the environment where they live.

Table 1. Provisional Estimates of Potential Residential Polluters in the United States

Watershed Behavior Prevalence in Overall Estimates of Potential Residential Polluters

Population

Over-Fertilizers 35% 38 million

Bad Dog Walkers 15% 16 million

Chronic Car washers 25% 27 million

Septic Slackers 15% 16 million

Bad Mechanics 1 to 5% 3 million

Pesticide Sprayers 40% 43 million

Hosers 15% 16 million

Notes: estimates are based on 1999 U.S. population of 270 million, 2.5 persons per household, and average behavior prevalence rates based on

numerous market surveys (See references).

230
Most Residents are Only Dimly Aware of the Watershed Concept.

It stands to reason that if citizens are asked to practice a watershed ethic, they will need to know what a watershed

is. Surveys indicate, however, that the average citizen is unaware of the watershed concept in general, and does not fully

understand the hydrologic connection between their yard, the street, the storm sewer, and (finally) local streams. Resident

surveys also continue to show limited or incomplete understanding of terms such as “watershed”, “stormwater quality”

or “runoff pollution”. For example, a recent Roper survey found that only41 % of Americans had any idea of what the term

watershed meant (NEETF, 1999). The same survey found that just 22% of Americans know that stormwater runoff is the

most common source of pollution of streams, rivers, and oceans.

At the same time, most of us claim to be very environmentally aware. For example, a Chesapeake Bay survey

reported that 69% of respondents professed to be very active or at least somewhat active in helping to reduce pollution

in the environment (SRC, 1994).

Resources Devoted to Watershed Education are Inadequate.

In recent years, several communities have developed education programs to influence the watershed behaviors

practiced by their residents. Most of these efforts, however, are run on a shoestring. For example, CWP recently surveyed

50 local programs that have tried to influence lawn care, septic cleaning and pet waste behaviors (Swann, 1999). These

education programs are typically run by the cooperative extension services, local recycling or stormwater agencies, or

urban soil and water conservation districts. Most are poorly staffed (0.1 to 0.5 staff years), relatively new (within last five

years), and have tiny annual budgets ($2,000 to $25,000). Given these limited resources, most watershed education

programs have no choice but to practice retail, rather than wholesale, outreach techniques. Consequently, most

watershed educators rely heavily on low-cost techniques such as brochures, posters, workshops, and demonstration

projects to send their message out.

The Marketing Techniques We Can Afford Don’t Reach Many People

Watershed managers need to send a clear and simple educational message that can attract the attention of the

average citizen who is simultaneously bombarded by dozens of competing messages every day. A number of surveys

have asked residents which outreach techniques are most influential in attracting their attention (Table 2). Messages sent

through television, radio and local newspapers are consistently more influential in reaching residents than any other

technique, with up to 30% recall rates by the watershed population for each technique. By contrast, messages transmitted

through meetings, brochures, local cable and videos tend to be recalled by only a very small segment of the watershed

population.

Table 2. Most Influential Methods of Getting Messages to Citizens, in 8 Citizen Surveys

II W A OR CA CA

(Elgin, 1996) (AMR,1997) (As-sing, 1994) (Pellegrin, $0,1994)

WI MN

(Simpson, (Morris et al.,

T V TV ad

TV ad TV

Newspaper Newspaper

Local paper Radio Ad

Video Brochure

Brochure Radio news

Local cable Paper Ad

Meeting Billboard

Direct Mail

TV ad

Newspaper

Radio

TV

Bill Insert

Newsletter

Local paper

TV Ad

Stencils

Billboard

Local paper

Brochure

Radio Ad

Bus Sign

Direct Mail

TV

Paper

Radio

Magazine

Neighbors

School

Billboard

Brochure

TV

Paper

Cable TV

Local paper

News-letter

Video

Meetings

Brochure

TV Newspaper

Paper Direct Mail

Newsletter TV

Brochure Neighbors

Site Visit Ext Service

Video Radio

Meeting Meeting

__ Local cable

One clear implication is that watershed education efforts must utilize a mix of outreach techniques if they are going

to get the message across to enough residents to make a difference in a watershed. Most existing watershed education

programs, however, cannot afford to use the more sophisticated wholesaleoutreach techniques that are most effective

231
Outreach Method

Figure 1. Outreach Methods Preferred By Residents Compared to Those Used by Education Programs.

at reaching the public with their watershed message. This gap is evident in Figure 1, which compares the outreach

methods actually used by local watershed education programs with the outreach methods that residents prefer, based

on responses from the Chesapeake Bay survey (Swann, 1999).

Crafting Better Watershed Education Programs

The first step in crafting better watershed education programs is to compile some baseline information on local

awareness, behaviors and media preferences. Some of the key questions watershed managers should consider are:

Is the typical individual aware of water quality issues in the watershed they live in?

. Is the individual or household behavior directly linked to water quality problems ?

b Is the behavior widely prevalent in the watershed population ?

b Do specific alternative(s) to the behavior exist that might reduce pollution?

b What is the most clear and direct message about these alternatives?

+ What outreach methods are most effective in getting the message out ?

b How much individual behavior change can be expected from these outreach techniques?

The best way to elicit this information is to conduct a market survey within the watershed. These market surveys are

useful for two purposes: to gauge the level of watershed awareness and interest within the general population, and to

determine if there is a segment of the population where education efforts should be focused to achieve the best returns

in behavioral changes for the money spent.

232
Perhaps the most critical step in crafting an education program is to select the right outreach techniques to send the

watershed message. Several communities have recently undertaken before and after surveys to measure how well the

public responds to their watershed education programs. From this research, two outreach techniques have shown some

promise in actually changing behavior - media campaigns and intensive training. Media campaigns typically use a mix

of radio, TV, direct mail, and signs to broadcast a general watershed message to a large audience. Intensive training use

workshops, consultation and guidebooks to send a much more complex message about watershed behavior to a smaller

and more interested audience. Intensive training often requires a time commitment of several hours from residents.

Both media campaigns and intensive training can produce up to a20% improvement in selected watershed behaviors

among their respective target populations (Tables 3 and 4). Both outreach techniques are probably needed in most

watersheds, as each complements the other. For example, media campaigns cost just a few cents per watershed resident

reached, while intensive training can cost a few dollars for each resident that is actually influenced. Media campaigns are

generally better at increasing watershed awareness, and sending messages about negative watershed behaviors.

Intensive training, on the other hand, is superior at changing individual practices in the home, lawn and garden.

Table 3. Effectiveness of Media Cam1

Location and Nature of Targeted

Campaign

San FranciscoRadio, TV and Buses

(BHI, 1997)

Los Angeles Radio and Newspapers

(Pellegrin Research Group, 1998)

Oregon Radio, TV (Advanced

Marketing Research, 1997)

Oakland County, Ml

Direct Mail (Public Sector Consultants,

1994)

)aigns in Influencing Watershed Behaviors: Four Surveys

Effectiveness of Campaign

Awareness increased 1 O-l 5%

Location and Nature of Training

Campaign

Maryland Direct Homeowner

(Smith, 1996)

Florida Master Gardener

(Knox, 1995)

Virginia Master Gardener

(Aveni, 1998)

Homeowners who reduced lawn chemicals shifted from 2 to 5%

Best recall: motor oil and litter (over 40%)

Worst recall: fertilizer and dog droppings (~10 %)

Drop in car washing, oil changing, radiator draining of about 5 to 7%

Greater self-reporting of polluting behaviors: dropping cigarette butts, littering, watering and letting water run

on street, hosing off driveways into the street (10% or more)

19% reported a change in “behaviors’‘-changes included being more careful about what goes down drain,

increasing recycling and composting, using more nature-friendly products etc.

44% of mail respondents recalled lawn care campaign

50% desired more information on lawn care and water quality

10% change in some lawn care practices as a result of campaign

(grass recycling, fertilizer use, hand weeding). No change in other

lawn care practices as a result of campaign

Effectiveness of Intensive Training

le 4. Effectiveness of Intensive Training in Changing Watershed Behaviors

10% shift from self to commercial car washing.

No change in fertilizer timing or rates.

Better claims of product disposal.

No significant change in fertilization frequency after program.

Some changes in lower rates, labels, slow release (8 to 15%).

Major changes in reduced pesticide use (10 to 40%).

30 to 50% increase in soil testing, fertilizer timing and aeration.

10% increase in grass clippings and 10% decrease in fertilizer rate.

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Both techniques work best when they present a simple and direct watershed message, are repeated frequently, utilize

multiple media and are directly connected to local water resources that are most important in the community.

Other important suggested considerations for effectively marketing a watershed message are to:

Develop stronger connections among the yard, the street, the storm sewer, and the stream. Outreach techniques

should continually stress the link between a particular watershed behavior and the undesirable water quality it helps to

create (i.e., fish kills, beach closure, algae blooms). Several excellent visual ads that effectively portray this link are

profiled in our watershed outreach award winners.

Form regional media campaigns. Since most communities operate on small budgets, they should consider pooling

their resources to develop regional media campaigns that can use the outreach techniques that are proven to reach and

influence residents. In particular, regional campaigns allow communities to hire the professionals needed to create and

deliver a strong message through the media. Also, the campaign approach allows a community to employ a combination

of media, such as radio, television, and print, to reach a wider segment of the population. It is important to keep in mind

that since no single outreach technique will be recalled by more than 30% of the population at large, several different

outreach techniques will be needed in an effective media campaign.

Use television wise/y. Television is the most influential medium for influencing the public, but careful choices need

to be made on the form of television that is used. Our surveys found that community cable access channels are much

less effective than commercial or public television channels. Program managers should consider using cable network

channels targeted forspecificaudiences, and develop thematicshows that capture interest of the home, garden and lawn

crowd (i.e., shows along the lines of “This Old Watershed”). Well-produced public service announcements on commercial

television are also a sensible investment.

Understand the demographics of your watershed. The middle-aged male should usually be the prime target for

watershed education, as he is prone to engage in more potentially polluting watershed behaviors than other sectors of

the population. Indeed, the most important audience for the watershed message includes men in the 35 to 55 year age

group with higher incomes and education levels. Specialized outreach techniques can appeal to this group, such as radio

ads on weekend sports events.

Another target group worth reaching includes what Pellegrin (1998) terms the “rubbish rebels”-- 18 to 25 year olds

who tend to have low watershed awareness, engage in potentially polluting behaviors, and are often employed in lawn

care and other service industries. This age group is hard to reach using conventional techniques, but may respond to ads

on alternative radio, concerts, and other events that celebrate the watershed.

As communities become more diverse, watershed managers should carefully track the unique demographics of their

watersheds. For example, if many residents speak English as a second language, outreach materials should be produced

in other languages. Similarly, watershed managers should consider more direct channels to send watershed messages

to reach particular groups, such as church leaders, African American newspapers, and Spanish-speaking television

channels.

Watershed educators should also be careful about using the traditional environmental education model that uses

schools to educate children who in turn educate their parents. While this model was instrumental in achieving greater

rates of recycling, it may not be as effective in changing watershed behaviors. While it is important to educate the next

generation of fertilizers, dog walkers, septic cleaners, and car washers, we need to directly influence the “boomer’

generation now.

Keep the watershedmessagesimpleandfunny. Watershed education should not be preachy complex, or depressing.

Indeed, the most effective outreach techniques combine a simple and direct message with a dash of humor.

Make information packets small, slick, and durable. Watershed educators should avoid the ponderous and boring

watershed handbook that looks great to a bureaucrat but ends up lining the bottom of a bird cage. One solution is to

create small, colorful and durable packets that contain the key essentials about watershed behaviors, with contact

234
information to get better advice. These packets can be stuck on the refrigerator, the kitchen drawer or the workbench for

handy reference when the impulse for better watershed behavior strikes.

Educate private sector allies. A wide number of private sector companies may potentially stand to benefit from

changes in watershed behavior. Better watershed behavior can drum up more sales for some companies, such as septic

tank cleaners, commercial car washes, and quick oil change franchises -- although they may need some help in crafting

their watershed marketing pitch.

Clearly, the potential exists for lawn care companies and landscaping services to shift their customers toward more

watershed-friendly practices. Nationally, lawn care companies are used by up to 50% of consumers, depending on

household income and lot size. Lawn care companies can exercise considerable authority over which practices are

applied to the lawns they tend, as long as they still produce a sharp looking lawn. For example, 94% of lawn care

companies reported that they had authority to change practices, and that about 60% of their customers were “somewhat

receptive to new ideas” according to a Florida study (Israel et al, 1995). De Young (1997) also found that suburban

Michigan residents expressed a high level of trust in their lawn care company.

Indeed, a small, but growing proportion of lawn care companies feel that environmental advertising makes good

business sense and can increase sales (Israel et al, 1995). Clearly, intensive training and certification will be needed to

ensure that watershed-friendly ads reflect good practice and not just slick salesmanship. It needs to be acknowledged

that lawn care companies strongly committed to practices that reduce fertilizer and pesticide inputs need to be strongly

endorsed by local government. Right now, it is not likely that such companies would be selected by the average

consumer, as consumers primarily rely on direct mail, word of mouth, and cost when choosing a lawn care company

(Swann, 1999 and AMR, 1997). For example, in the Chesapeake Bay survey, only two percent of residents indicated that

they had chosen a lawn care company primarily on the basis that it was “environmentally friendly” (Swan& 1999).

Lawn and garden centers are another natural target for watershed education. Study after study indicates that product

labels and store attendants are the primary and almost exclusive source of lawn care information for the average

consumer. At first glance, national retail chains should be strongly opposed to better watershed behavior, since it would

sharply cut into lawn and garden product sales and the lucrative profits they produce (even at the expense of the

community and environmentally friendly image they often market). The key strategy is to substitute watershed-friendly

products for ones that are not, and to offer training for the store attendants at the point of sale on how to use such

products.

Summary

For the watershed manager faced with new regulatory requirements under Phase II of the NPDES program, the

creation of an effective watershed education program should be a high priority. Not only is public education a mandated

component of an NPDES permit, but in urbanized areas it may the most cost-effective tool available to achieve water

quality goals. For smaller communities with scant budget and staff resources, it is imperative that these education

programs be productive in terms of changing behaviors and raising awareness of individual actions on local water quality.

Perhaps the most important factor in creating an effective watershed education program is selecting the right outreach

methods. Market surveys will often answer questions regarding the level of environmental awareness of watershed

residents, what forms of informational outreach attract their attention, and resident willingness to change pollutant

producing behaviors. This information allows the watershed manager to tailor outreach methods to specific target groups

where behavior change is most likely. These surveys will also establish the demographics of the residents and determine

whether multilingual outreach is required.

Watershed managers should also consider innovative approaches to sending out their pollution reduction messages.

Pooling resources with other communities to create regional media campaigns and the use of outreach opportunities

through private sector education are just two ways that program managers can reach broader audiences without spending

large amounts of money.

235
Continued development of productive outreach methods and innovative techniques is necessary to relay the basic

premise of watershed education - that we live in a watershed and how to properly live within it - in the most economical

and effective manner.

References

Advanced Marketing Research (AMR). 1997. Stormwatertracking study. City of Eugene, Oregon. Unpublished marketing

survey.

Assing, J. 1994. Survey of public attitudes. February and July, 1994. Russian Hill Associates. Alameda County Urban

Runoff Clean Water Program. San Francisco CA. 84 pp.

Aveni, M. 1998. Water-wise gardener program: summary report. Unpublished Data. Virginia Cooperative Extension.

Prince William County, VA.

Big Honking Ideas, Inc (BHI). 1997. Final report: Spring regional advertising campaign. Prepared for Bay Area Stormwater

Management Agencies Association. Oakland, CA.

De Young, R. 1997. Healthy lawn and garden survey: data analysis report. Rouge River National Wet Weather

Demonstration Project. Oakland County, Ml. 40 pp.

Elgin DDB. 1996. Public awareness study: summary report. The Water Quality Consortium. Seattle, WA. 24 pp.

Israel, G., S. Pinheiro and G. Knox. 1995. Environmental landscape management -- assessing practices among

commercial groups. University of Florida. Cooperative Extension Service. Bulletin 307. Monticello, FL. 18 pp.

Knox, G., A. Fugate and G. Israel. 1995. Environmental landscape management--use of practices by Floridaconsumers.

University of Florida Cooperative Extension Service. Bulletin 307. Monticello, FL. 26 pp.

Morris, W. and D. Traxler. 1996. DakotaCountysubwatersheds: residential survey on lawn care and water quality. Dakota

County, Minnesota, Decision Resources, Ltd.

National Environmental Education Training Foundation (NEETF). 1999. National Report Card on Environmental

Knowledge, Attitudes and Behaviors: Seventh Annual Roper Survey of Adult Americans. National Environmental

Education Training Foundation, Washington, D.C.

National Service Research (NSR). 1998. Pesticide usage and impact awareness study: executive summary. City of Forth

Worth Water Department. Fort Worth Texas. 44 pp.

Pellegrin Research Group. 1998. Stormwater/urban runoff public education program: interim evaluation, resident

population. Los Angeles County Department of Public Works. 28 pp.

Public Sector Consultants, Inc (PSC). 1994. A strategy for public involvement. Rouge River National Wet Weather

Demonstration Project. 56 pp.

Simpson, J. 1994. Milwaukee survey used to design pollution prevention program. Technical Note 37. Watershed

Protection Techniques. 1(3):133-l 34.

Smith, J. 1996. Public survey used to estimate pollutant loads in Maryland. Technical Note 73. Watershed Protection

Techniques. 2(2): 361-363.

Survey Research Center (SRC). 1994. The Chesapeake Bay attitudes survey. Communications subcommittee.

Chesapeake Bay Program. U.S. Environmental Protection Agency. 42 pp.

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Swann, C. 1999. A survey of residential nutrient behaviors in the Chesapeake Bay. Widener-Burrows, Inc. Chesapeake

Research Consortium. Center for Watershed Protection. Ellicott City, MD. 112 pp.

237
Lawn Care and Water Quality: Finding the Balance

Jerry Spetzman

Minnesota Department of Agriculture

St. Paul, MN 55107-2094

email: Jerome.SpetzmanBState.MN.US

Abstract

When land is converted from natural areas to developed urban areas, pavement and rooftops replace grass and trees.

Water flows over driveways, streets and parking lots taking with it particles and debris in its path and depositing them,

via storm sewers, into nearby lakes, creeks and rivers. This non-point source pollution can contain sediment, debris,

fertilizers, pesticides, leaves, grass clippings, motor oil, or pet wastes. Small amounts of these materials entering a lake

or river are not generally considered harmful. But when small amounts are multiplied by thousands or tens of thousands

they can cause serious water quality problems.

Since 1993, the Minnesota Department of Agriculture, in cooperation with several other organizations, has been

gathering information on homeowner use of pesticides and fertilizers in the Twin Cities metropolitan area. This

information includes the amounts of lawn care products used by homeowners, where they are purchased, how they are

applied, and whether or not they have an effect on nearby lakes, creeks or rivers.

Residents living in two watersheds were selected to participate in a focused study. Lake Harriet represents urban

watersheds and Lake Alimagnet represents suburban watersheds. Based on survey results and water quality monitoring,

education materials were developed to promote public awareness of lawn practices and their potential to affect water

quality. These educational materials incorporate the concept that “everyone lives in a watershed’and that everyone has

the potential to affect water quality, whether or not they actually live on a lake shore.

What are the Lake Harriet and Lake Alimagnet Watershed Awareness Projects?

The projects have two purposes: (1) to inform urban and suburban homeowners about living in a watershed, and (2)

to help them learn how their lawn care habits can affect the quality of Twin Cities water. The project’s goal is to improve

water quality by reducing the quantity of pesticides and nutrients through responsible use of those materials.

How has this goal been achieved?

Project members have:

l Surveyed the current lawn care habits of homeowners and measured the effects of those habits by monitoring

pesticide and nutrient runoff into Lake Harriet

l Informed homeowners about how their lawn care habits affect Twin Cities waters

l Asked homeowners how the projects have affected their lawn care practices

l Monitored runoff into Lake Harriet to quantify changes brought about by homeowner actions

l Drawn on detailed Lake Harriet experience to design urban watershed education materials for use throughout

Minneapolis and Minnesota--these materials were tested in the Lake Alimagnet watershed

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What is a watershed?

It is an area of land over which rain and melted snow flows to lakes, rivers, and wetlands. There are 46 major

watersheds and 255 sub-watersheds in the Minneapolis-St. Paul metropolitan area.

The Lake Harriet watershed is a 1,139-acre area in a well-established residential neighborhood with almost 6,000

homeowners. The Lake Harriet study area is a 148-acre portion of the watershed. About 40% of the study area is

covered with hard surfaces, such as pavement and rooftops. About 700 homeowners live in the study area, most in

detached, single family houses built in the early 1900s. The water quality in Lake Harriet is very good for a Twin Cities

lake.

A survey of 105 Lake Harriet watershed residents most familiar with lawn care done on their own properties, showed

that:

l They are highly educated (college or post-graduate degrees predominate)

l Their average age is 47

l They have middle- to upper-level incomes

l They care for their lawns by mowing regularly and using fertilizers and herbicides

l A few use professional lawn care services

The Lake Alimagnet watershed has approximately 3600 suburban households. Of this number, a large proportion

is made up of townhouse residents. The Lake Alimagnet watershed was developed in the 1960s. Homeowners are welleducated and have middle- to upper-middle incomes. The water quality in Lake Alimagnet is considered poor, algae

blooms are common, and the predominant fish species is bullhead.

Why are we studying the Lake Harriet and Lake Alimagnet watersheds?

Because they provide good examples (respectively) of how urban and suburban development affect our water

resources and because they are sources of year-round recreation for many Twin Cities residents. These residents are

vitally interested in keeping the water clean.

What are we finding out?

Though Lake Harriet had some of the highest quality water in the Twin Cities, that quality has also declined over time.

Lake Harriet has poor quality water and area residents want to reverse the trends.

These projects and others have monitored storm water, rainfall, and lake water to determine the levels of non-point

source pollutants in Lake Harriet. Specifically, this project monitored two types of pollutants: pesticides, which can affect

water quality, and phosphorus, which can increase lake algae growth and reduce water quality.

Pesticide monitoring

The Lake Harriet project monitored storm runoff, rainfall, and lake water. The water quality monitoring consisted of

a permanent automatic sampling station installed in a storm drain outlet which carried watershed runoff into Lake Harriet;

samples were taken during storm events, from which mass loading of pesticides and nutrients were calculated. In addition,

a rainfall monitoring station sampled rain events. Finally lake monitoring samples were collected during the growing

season. Several hundred samples were analyzed for more than 30 pesticides.

The education program included several methods of education, including homeowner meetings, direct mail, flyers,

billboards, utility bill inserts, local newspaper articles and visits by Master Gardeners. Because monitoring preceded the

239
education, and also followed it,reductions in pesticides can be measured. There was a decrease in average pesticide

loads between the earlier and later monitoring periods. Therefore, the annual storm sewer runoff load of pesticides to Lake

Harriet was reduced during the Lake Harriet project. The largest decreases came from the four compounds listed on this

table:

Lawn Herbicides

MCPA

Dicamba

2,4-D

MCPP

Percent Decrease

(1992-l 995)

86%

59%

58%

56%

The most prevalent pesticides found during monitoring were herbicides (weedkillers). The eight herbicides listed

on the following table accounted for 95% of all pesticide detections.

Lawn Herbicides Agricultural Herbicides

MCPA Alachlor

Dicamba Atrazine

2,4-D Cyanazine

MCPP Metolachlor

l Storm water runoff monitoring summary:

l Lawn herbicides were found in 80% of the storm runoff events sampled between April and October.

l Agricultural herbicides were detected in 35% of the storm events sampled

l Rainfall monitoring summary:

l The agricultural herbicides listed above (the only herbicides found in rainfall samples) were atmospherically

deposited by wind and rainfall onto the watershed and the accompanying water bodies.

9 Lawn herbicides were not detected in rainfall samples.

l Lake monitoring summary:

l The three most commonly detected compounds in lake water were MCPP, Atrazine, and 2,4-D. They were also

the most frequently detected compounds in stormwater entering Lake Harriet.

l Phosphorus monitoring:

Analyses revealed the phosphorus in runoff peaks twice a year, in the spring and in the fall.

l In the spring, melting snow carries phosphorus attached to tiny particles of grit, sand, and organic matter as it

enters the storm sewers.

240
. In the fall, phosphorus in leaves, grass clippings, and other organic debris enters the storm sewers. Studies

conducted by other researchers established that only a small percentage of phosphorus in runoff results from

appropriate use of fertilizer on lawns.

l Water Quality Education

Lake Harriet and Lake Alimagnet project participants have concluded that educating homeowners living in the

watershed is one of the best ways of reducing pollution in the lake. Billboards, brochures, and water bill inserts have

carried messages based on the following two concepts:

l A healthy lawn and landscape promotes healthy waters. Home landscaping with regionally adapted, healthy

plants can help absorb and filter rainfall, irrigation, and runoff from melted snow.

l Keep your lawn and landscape healthy as follows:

l Apply pesticides and nutrients according to recommendations

l Aim roof downspouts onto lawns and gardens to filter and absorb runoff

l Keep grass clippings and leaves off streets, sidewalks, and driveways

l Leave grass clippings on the lawn or compost them

l Use fallen leaves as winter or summer mulch, compost them, or shred them and leave them on the lawn

l Keep lawn care products on the lawn and always follow label instructions

l Clean up and reuse granular lawn care products that fall on streets, sidewalks, and driveways

Project Evaluation

l Based on feedback from homeowners living in the Lake Harriet and Lake Alimagnet watersheds, we have

concluded the following:

l Most homeowners in the Lake Harriet watershed apply significantly less lawn fertilizer than the University of

Minnesota’s recommended guidelines.

l Most homeowners compost grass clippings or leave them on their lawns.

l Homeowners would rather spot-treat weeds than apply herbicide to their entire yard or use non-chemical weed

control methods.

l Top soil in the Lake Harriet watershed is significantly deeper than that found in the Lake Alimagnet watershed.

In many cases when suburban areas are developed, top soil is removed, but not replaced. This results in

decreased plant vigor, and an increase in the need to fertilize, water, and maintain turf.

l Most homeowners feel the educational initiative has increased their understanding of how lawn care habits affect

water quality. Neighborhood newspapers and direct mail, the most common source of lawn care and water

quality information, have the greatest impact.

l Messages that are quick to read and easy to understand are the most effective in changing lawn care habits.

l These messages are best delivered over an extended period. Homeowners have been reached through fliers,

newspaper articles, brochures, direct mail, handouts, and personal contacts.

241
Feedback also shows that homeowners still need to hear the following messages:

l You can preserve water quality and have a healthy lawn by applying lawn care products in appropriate amounts,

at the right times, and during suitable (or appropriate) weather conditions.

l By keeping leaves out of storm sewers, you can help reduce the amount of phosphorus carried to the lake in runoff

water.

l Fall is the best season to apply turf fertilizers and lawn care products that control broadleaf weeds. The primary

growth of turf grasses is early fall until late spring.

l Erosion, leaves, grass clippings, yard waste, pet waste, and rainfall all contain pollutants that can end up in lake

water.

Lake Alimagnet Project Results

During the project period, the water quality in Lake Alimagnet improved significantly.

. Project cooperators achieved improvements in total phosphorus and chlorophyll-a.

l The best secci disk reading ever on Lake Alimagnet was recorded.

9 The Citizens Assisted Monitoring Program improved the ranking of Lake Alimagnet from a “D” to a “C.”

These results may be a result of the project, a curly leaf pond weed cutting, or may be credited to El Nino.

For more information on the Lake Harriet or Lake Alimagnet Watershed Awareness Projects and samples of

homeowner education materials, please contact the Minnesota Department of Agriculture at (651) 297-7269.

242
San Francisco Bay Area’s Pesticide

Toxicity Reduction Strategy

Geoff Brosseau

Bay Area Stormwater Management Agencies Association (BASMAA)

Oakland, California

Introduction

Water quality research conducted by San Francisco Bay Area stormwater programs and wastewatertreatment plants

over the last several years has identified widespread toxicity in local creeks and wastewater treatment plant effluent

(California Regional Water Quality Control Board, 1997; San Francisco Bay Area Pollution Prevention Group, 1998). The

toxicity problem was ultimately traced to diazinon and chlorpyrifos-commonly used organophosphate pesticides available

in hundreds of consumer products (Alameda Countywide Clean Water Program, 1997). Study results indicated that

pesticide use according to label instructions could not be ruled out as a cause of wastewater and stormwater toxicity

(Regional Water Quality Control Plant-Palo Alto, 1996). In May 1999, San Francisco Bay and 35 Bay Area urban creeks

were listed by the U.S. Environmental Protection Agency (USEPA) as impaired by diazinon (USEPA, 1999).

Impact of 303(d) Listing on Local Governments

In its action, USEPA listed 53 waterbodies in California as impaired due to diazinon in urban runoff and 7 waterbodies

as impaired due to chlorpyrifos in urban runoff. By definition under the Clean Water Act, this action means that there is

a water quality problem, regardless of the problem definitions under the Federal Insecticide, Fungicide and Rodenticide

Act (FIFRA) (i.e., “unreasonable adverse effect”) or the Food Quality Protection Act (FQPA). The listing action put over

100 municipalities in the San Francisco Bay Area and Central Valley at immediate regulatory, legal, and financial risk.

l Regulatory risk -The State Water Resources Control Board and USEPA can take enforcement action against, and

fine, these municipalities for violating their NPDES (National Pollutant Discharge Elimination System) stormwater

permits.

l Legal risk - Citizen and environmental groups can sue municipalities for the same reasons.

l Financial risk - These municipalities must now spend local public tax dollars proactively addressing this problem,

and potentially reacting to fines and lawsuits.

Municipalities’ Response

To comply with their NPDES stormwater permits, municipalities must meet two broad goals:

1. Effectively prohibit non-stormwater discharges into storm sewers.

2. Reduce the discharge of pollutants to the maximum extent practicable (MEP).

To meet these goals and to address the 303(d) listing, there are a number of actions Bay Area stormwater programs

have taken or plan to take that may reduce pesticide-related toxicity in surface waters. These actions are packaged in

a Pesticide Toxicity Reduction Strategy (BASMAA, 2000). The Strategy is a multi-faceted effort including:

l Education/outreach including:

243
l limiting or prohibiting pesticide use by municipal staff and contractors and/or requiring use of best management

practices (BMPs) such as Integrated Pest Management (IPM)

l providing adequate and convenient options for disposal of unused pesticides and pesticide containers through

household hazardous waste collection programs

. educating residents about pesticide-related toxicity and proper use and disposal through distribution of

educational materials, and development and implementation of media and advertising campaigns

l educating residents about alternative methods and products through such programs as demonstration gardens

and point-of-purchase campaigns in hardware stores and nurseries

l educating businesses about proper use and disposal, as well as alternative methods and products for use around

their own properties and facilities

l educating pest control operators and working with them to develop BMPs protective of surface waters

l Regulatory- Identifying opportunities to reduce toxicity and advocating state and federal agencies to seize these

opportunities through regulation and re-registration

l Monitoring - Investigating the extent and causes of toxicity, and assessing impacts on beneficial uses

The IPM Store Partnership

One exemplary part of the Pesticide Toxicity Reduction Strategy worth describing in more detail is the IPM (Integrated

Pest Management) Store Partnership. In 1997, the Central Contra Costa Sanitary District (CCCSD), a wastewater

treatment plant located in Martinez, California, jointly developed and successfully piloted the IPM Store Partnership with

the Regional Water Quality Control Plant (Palo Alto, California) in four locally owned garden centers and hardware stores.

In 1998, the Bay Area Stormwater Management Agencies Association (BASMAA) and the San Francisco Bay Area

Pollution Prevention Group (BAPPG) joined together to fund the expansion of the IPM Store Partnership to more stores

in the San Francisco Bay Area. By spring 1999, 116 stores in eight Bay Area counties were participating in the

Partnership.

The Partners

BASMAA is a consortium of seven San Francisco Bay Area municipal stormwater programs. These programs

represent more than 90 agencies, including 79 cities and 6 counties, and the bulk of the watershed immediately

surrounding San Francisco Bay. BASMAA agencies agree to a memorandum of understanding and each year collect

dues, prorated by population, from their members for a “baseline” program that provides for staff and finances

projects-like the IPM Store Partnershipthat are endorsed by all member agencies.

The BAPPG is a voluntary association of 39 wastewater treatment plants working together to prevent water pollution

in the San Francisco Bay. These agencies represent all of the publicly owned municipal wastewater agencies that

discharge into San Francisco Bay in the nine Bay Area counties, and almost all of the watershed immediately surrounding

San Francisco Bay. BAPPG’s decision-making is done by consensus. Each year, a work plan-with an associated

budget-is developed. The budget is allocated among the 39 plants based on the average amount of treated wastewater

discharged each day. Contributions are voluntary, although all agencies do contribute. These contributions are used to

fund projects like the IPM Store Partnership.

Integrated Pest Management

There are many definitions of Integrated Pest Management. The definition used to guide the IPM Store Partnership

was the following:

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Integrated Pest Management is an approach that uses regular monitoring and cultural, biological, and physical

methods to keep pests at acceptable levels. Only less toxic chemicals are used and only as needed.

IPM was used as the basis for the program because it: (1) focuses on effective alternatives to traditional chemical

pesticides; (2) does not substitute another pesticide that may become tomorrow’s problem, and (3) does not preclude the

use of chemicals in all situations.

Although promotion of IPM was the basis for the program, the term itself is somewhat problematic. The terms “IPM”

and “Integrated Pest Management” were used in speaking with experts and agencies familiar with the jargon, but these

terms were avoided in communications with the non-initiated (e.g., general public). In addition, the term IPM was not very

representative of the situation in the store between the customer and the store employee. Most customers go to a store

for help when pests have already reached unacceptable levels, so store employees must start with controlling a pest

problem, rather than preventing it, which is the first step in IPM. Despite this challenge, customers were exposed to the

full range of IPM methods through the fact sheets and display materials, as well as less-toxic products.

Goals

The goals of the IPM Store Partnership are to:

l Educate the public about the value of IPM approaches to pest control and safe use and disposal of pesticides, when

used

l Deliver IPM-related messages without negative messages about any products

l Develop partnerships with retailers so that they can help spread the word about water quality problems related to

residential pesticide use

l Provide consistent messages

9 Capitalize on economies of scale

l Prepare the stage for regional program expansion into chain stores

Program /Yemen ts

The IPM Store Partnership is an education program for employees and customers of locally owned garden centers

and hardware stores. The project elements include:

l development and production of eight fact sheets on less-toxic pest management strategies for the public (Naturally

Managing Pests, Controlling Ants, Controlling Aphids in Your Garden, Keeping Cockroaches Out of Your House,

Keeping Fleas Off Your Pets and Out of Your Yard, Living with Spiders, Tips for a Healthy Beautiful Lawn, and Safe

Use and Disposal of Pesticides)

l development of an extensive list of less-toxic methods and products preferable to diazinon and chlorpyrifos for

various applications

l training sessions for store employees focusing on principles of Integrated Pest Management and successful

application strategies for products on the less-toxic list

l design and production of a program logo and in-store promotion materials including “end cap” displays, posters,

shelf-talkers, shelf signs, and vinyl banners

l program evaluation by a San Francisco State University-affiliated survey research and data analysis firm

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Results and Discussion

Although the final evaluation will not be complete until the end of the 1999 in-store promotion season (late 1999), the

sponsoring agencies expect it to be successful based on preliminary findings and on the success of the pilot project.

Feedback from store owners and employees that participated in the pilot was uniformly positive. The sales data in the

pilot IPM Store Partnership showed variations from store to store. One store found that sales of all but one diazinon and

chlorpyrifos product dropped. At the same time, less-toxic product sales experienced an overall 17% increase and profits

were not affected.

It is the hope of the participating agencies that the final evaluation and report on the 1999 Partnership will be useful

as a model and primer for other agencies and jurisdictions concerned about pesticide-related toxicity in surface waters

and interested in building educational partnerships with local businesses. While Bay Area water pollution prevention

agencies have been coordinating their public education efforts since the early 199Os, the IPM Store Partnership is the

first point-of-purchase program implemented regionally. All of the general benefits of inter-agency coordination (support

for smaller agencies, cost savings, options for pooled advertising and media relations) are magnified in such a large

undertaking.

Based on the partnership’s success, all of the agencies that participated in the 1999 Partnership allocated funds for

continuation of the program in 1999-2000. BASMAA and the BAPPG again contributed funds to regional coordination.

Brainstorming sessions were held in late summer 1999 to determine how to improve the program, and minor modifications

were made for 2000.

The IPM Store Partnership is one example of BASMAA and the BAPPG’s commitment to use public resources

efficiently. Given that philosophy, materials developed by the IPM Store Partnership are available to agencies interested

in implementing a similar program.

Other Aspects of the Strategy

Despite the success of the IPM Store Partnership and many of the other educational aspects of the Pesticide Toxicity

Reduction Strategy, it is clear to Bay Area water pollution prevention agencies that their efforts alone will not be enough

to solve the problem. Study results indicate that less than 1% of applied diazinon runs off, yet it takes less than a fluid

ounce of active ingredient flushed into stormwater runoff to cause toxicity in urban creeks (Regional Water Quality Control

Plant-Palo Alto, 1996). Educational programs run by Bay Area water pollution prevention agencies are some of the most

developed in the country and they have won numerous awards for their quality and effectiveness. Nevertheless, even

the best education programs are not 100% effective. It is clear that education alone will not solve this problem.

San Francisco Bay Area stormwater programs are and will continue to address the problem of pesticide-related

toxicity in surface waters by way of meeting the MEP requirement in their NPDES permits. These agencies have gone

so far as to develop the Pesticide Toxicity Reduction Strategy described above that includes three elements-education,

regulatory, and monitoring. The authority and ability of local governments to implement the strategy varies with each

element. The most cost-effective and appropriate aspect for local governments to implement is education. For the

regulatory and monitoring elements, local governments can, and have, identified the issues and opportunities to reduce

pesticide-related toxicity, but they have limited ability or authority to actually implement corrective actions.

Regulatory

Regulation of pesticides including their registration for use in the Unites States is the responsibility of USEPA.

California’s Department of Pesticide Regulation (DPR) has responsibility for regulating the sale and use of pesticides in

California. California DPR, with few exceptions, registers pesticides only after they have been registered by USEPA.

California DPR can not register pesticides which have been denied registration by USEPA. At the local government level,

the California Food and Agriculture Code grants some authority to county agricultural commissioners for local enforcement

of pesticide regulations, record keeping, and outreach to applicators. However, with the exception of county agricultural

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commissioners, local governmentsare prohibited from regulating the registration, sale, transportation, or use of “economic

poisons.” This regulatory structure means that the ability and authority of local governments is limited to:

l identifying opportunities to reduce toxicity, such as eliminating potentially problematic uses, and advocating that

state and federal agencies seize these opportunities through regulation and re-registration

. in the case of wastewater and stormwater agencies, regulating the discharge of pesticides to the sewer or storm

drain to ensure local agencies’ compliance with state and federal laws (e.g., Clean Water Act)

Monitoring

Local governments have some ability, authority, and responsibility to use monitoring to address the problem of

pesticide-related toxicity of surface waters. To-date, San Francisco Bay Area municipalities have used monitoring to:

l identify and define the problem (Alameda County Urban Runoff Clean Water Program, 1995; Regional Water

Quality Control Plant-Palo Alto, 1996; California Regional Water Quality Control Board, 1997; San Francisco Bay

Area Pollution Prevention Group, 1998)

l characterize sources (Alameda Countywide Clean Water Program, 1997)

l recommend corrective actions (Alameda County Flood Control and Water Conservation District, 1997)

A review of monitoring data from around the country shows that municipalities in the San Francisco Bay Area and

California Central Valley are not alone in their identification of this environmental problem.

l Orange County, California (Lee, et al., 1999) - Multi-year studies of stormwater runoff in San Diego Creek as it

enters Upper Newport Bay have shown that the problem is not restricted to Northern California. Runoff from each

stormwater event has been shown to be toxic, and about half of the observed toxicity is due to diazinon and

chlorpyrifos used in urban areas for structural termite and ant control, and lawn and garden pest control.

l NAWQA (USGS, 1998) - Results from the United States Geological Survey’s (USGS) National Water Quality

Assessment Program from 1992 through 1996 show that the problem is in fact a national one. Over 300 samples

have been taken from eleven urban streams scattered across the country, from Florida to Connecticut to Oregon,

as part of the Pesticides National Synthesis Project. In a recent report on the first cycle of the program, USGS

concluded that “urban and suburban areas are substantial sources of pesticides to streams” and that “most urban

areas have similar pesticides in streams...and many urban areas may benefit from similar strategies for reduction.”

l Publicly-Owned Treatment Works survey (USEPA, 1989) - Results from a survey done 10 years ago by USEPA

show that pesticide-related toxicity is a wastewater problem as well as a stormwater problem. USEPA’s

Environmental Research Laboratory in Duluth, working through the National Effluent Toxicity Assessment Center

(NETAC), reported on the occurrence of diazinon in 28 POTW effluents. Diazinon was found in sixteen (62%) of

the effluents, and levels were greater than or equal to 250 rig/L for nine (32%) of the effluents. NETAC concluded

in part “The frequency with which we have observed diazinon in the past, in this survey, and continue to find it in

effluents is indicative of a widespread problem.”

Clearly this is a national problem caused by products that are registered at the national level and sold across the

country.

The pesticide registration process provides a built-in mechanism to use monitoring and science to address this

national problem. During the registration process, USEPA must review and summarize the findings of studies conducted

on each pesticide. During this step, USEPA may request that “registrants” (e.g., pesticide manufacturers) submit specific

studies for review. Based on its review, USEPA can confirm, deny, or change the pesticide’s registration including

approved uses, sites of application, formulations, and label directions.

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Local governments are willing to use monitoring and science to further investigate local impacts and sources, and

to host case studies, if USEPA will provide financial and other support, with the goal of conducting representative case

studies whose results can be extrapolated across the country. But given the established mechanism in the pesticide

registration process, it would be inappropriate and ineffective for local governments to do more. USEPA must exercise

its federal authorities and use monitoring and science information to make more informed, up-to-date registration

decisions.

Conclusion

Rather than being a tool in and of itself, the Pesticide Toxicity Reduction Strategy is really a toolbox. It includes a

number of effective tools for reducing pesticide-related toxicity of surface waters-an increasingly important part of urban

water resource management and protection. Every job has its tool and in the right pair of hands, the job can be easy and

cost-effective to complete. The wrong tool or the wrong hands can make the job difficult, if not impossible to finish. It

is the responsibility of government agencies to be clear and disciplined about which tool and which pair of hands go with

which job when fixing environmental problems. The extent to which they implement that concept will determine how

successful the work of environmental protection will be.

References

Alameda County Flood Control and Water Conservation District, 1997. Strategy to Reduce Diazinon Levels in Creeks

in the San Francisco Bay Area. Prepared by J. Scanlin and S. Gosselin.

Alameda County Urban Runoff Clean Water Program, 1995. Identification and Control of Toxicity in Stormwater

Discharges to Urban Creeks. Prepared by S.R. Hansen and Associates.

Alameda Countywide Clean Water Program, 1997. Characterization of the Presence and Sources of Diazinon in the

Castro Valley Creek Watershed. Prepared by J. Scanlin and A. Feng.

Bay Area Stormwater Mgt. Association, 2000. Strategy for Reducing Organophosphate Pesticide-Related Toxicity in San

Francisco Bay Area Urban Creeks.

California Regional Water Quality Control Board, 1997. Diazinon in Surface Waters in the San Francisco Bay Area:

Occurrence and Potential Impact. Prepared by T. Mumley (RWQCB) and R. Katznelson (Woodward Clyde Consultants).

Lee, G. Fred, et al., 1999. Evaluation of the Water Quality Significance of OP Pesticide Toxicity in Tributaries of Upper

Newport Bay, Orange County, CA. Environmental Toxicology and Risk Assessment: Recent Achievements in

Environmental Fate and Transport: Ninth Volume, ASTM STP 1381, American Society for Testing and Materials, West

Conshohocken, PA.

Regional Water Quality Control Plant-Palo Alto, 1996. Diazinon in Urban Areas. Prepared by A. Cooper.

San Francisco Bay Area Pollution Prevention Group, 1998. Diazinon & Chlorpyrifos Quantitative Identification for San

Francisco Bay Area Wastewater Treatment Plants. Prepared by T. Chew, K. Easton, and A. Laponis (Central Contra

Costa Sanitary District).

USEPA, 1989. Results of Diazinon Levels in POTW Effluents in the United States. National Effluent Toxicity Assessment

Center (NETAC) Technical Report 14-89. Environmental Research Laboratory-Duluth. Prepared by T. Norberg-King,

M. Lukasewcyz, and J. Jensen.

USEPA, 1999. 1998 California 303(d) List and TMDL Priority Schedule.

USGS, 1998. Pesticides in Surface and Ground Water of the United States: Summary of Results of the National Water

Quality Assessment Program (NAWQA) (http://water.wr.usgs.gov/pnsp/allsumm).

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Administering the NPDES Industrial Storm Water

Program at the Municipal Level

Michael J. Pronold

Bureau of Environmental Services

City of Portland

Portland, Oregon

Abstract

As part of the EPA Phase 1 stormwater requirements, certain classes of industries are required to obtain Industrial

Storm Water permits. The EPA, or a state agency that has been delegated by EPA, administers these permits. The

Phase 1 regulations also require that municipalities develop a program to monitor and control pollutants in storm water

runoff from industrial facilities. These are potentially non-coordinated requirements and can result in redundant efforts

and a less than efficient program. In addition, EPA and/or state agencies may not have the resources to adequately

administrate and enforce the permitting program while leaving the municipality liable for the discharges from the municipal

separated storm sewer system (MS4).

The City of Portland, Oregon (City), met the requirement in its municipal storm water permit to control industrial

stormwater sources of pollution by developing a Memorandum of Agreement (MOA) with the Oregon Department of

Environmental Quality (DEQ), (which is the delegated authority) to administer the permit program. The MOA provided

the City with the mechanism to administer the industrial stormwater permits for those facilities that discharge to the City’s

MS4. The City pursued this approach since it was responsible for the discharge from the MS4 and wanted to ensure that

it had adequate oversight of these discharges. By coordinating this effort with other ongoing industrial water quality

programs, the City could provide a more cost-effective program, considering the regulatory costs as well as cost to the

industry. City Code was developed to support this approach.

When the City took over the administration of the permits in 1994, over 50% of the facilities with a permit had not met

the requirements for the development of a storm water pollution control plan, the main requirement of the permit. In

addition, nearly 60% of the permitted facilities had not performed the required stormwater sampling. Of the samples

taken, approximately 30% violated standards in the permit. It was also evident that not all facilities required to obtain a

permit had done so. Efforts since 1994, have shown that only 25-30% of the facilities required to obtain a permit had

applied. A benefit of the local administration of the program is the detection of illicit discharges to the MS4.

Approximately 15% of all industrial inspections have identified illicit discharges.

The City has also identified certain classes of industries and activities that can be significant sources of pollutants

to the MS4. This has helped streamline the program efforts and redirect resources to where the greatest cost benefit will

be realized.

Introduction

Stormwater discharges have been increasingly identified as a significant source of water pollution in numerous

nationwide studies on water quality. To address this problem, the Clean Water Act Amendments of 1987 required EPA

to publish regulations to control storm water discharges under NPDES. EPA published storm water regulations (55 FR

47990) on November 16, 1990 which require certain dischargers of storm water to waters of the United States to apply

for NPDES permits. These regulations established NPDES permit application requirements for storm water discharges

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associated with large- and medium-size MS4.s. The regulations also established NPDES permit application requirements

for storm water discharges associated with industrial activity. EPA has defined this phrase in terms of 11 categories of

industrial activity.

A requirement of the City’s application process was “A description of a program to monitor and control pollutants in

storm water discharges to municipal systems from municipal landfills, hazardous waste treatment, disposal, and recovery

facilities, industrial facilities that are subject to Section 313 of Title III of the Super-fund Amendments and Reauthorization

Act of 1986 (SARA), and industrial facilities that the municipal permit applicant determines are contributing a substantial

pollutant loading to the municipal storm sewer system.” (40 CFR 122,26(d)(2)(iv)(C). This creates the potential for

redundant efforts and a less than efficient program.

The stormwater regulations envision that NPDES permitting authorities and municipal operators will cooperate to

develop programs to monitor and control pollutants in storm water discharges to MS4 from certain industrial facilities.

The NPDES permits for industrial facilities establish requirements such as controls, practices, and monitoring of

stormwater discharges, as well as provide a basis for enforcement actions. An integral part of the requirement is the

adequacy of legal authority. This will allow the municipality to implement its program, which should include inspections,

review of stormwater pollution control plans, monitoring, and implementation of control measures.

The municipality is ultimately responsible for discharges from its MS4. To meet the requirement in its municipal

stormwater permit, and to provide the oversight necessary to protect itself from liability, the City developed new legal

authority and entered into an MOA with the authorized NPDES state authority (DEQ), to administer the permits for those

discharges to the MS4.

Program Elements

Legal Authority

The City did not have adequate legal authority to oversee discharges to the MS4. In response to this, the City

developed code in February 1994. Some of the major provisions of the code are:

l Authority of the Director of Environmental Services to Adopt Rules

l General Discharge Prohibitions

l Discharge Limitations

l Reporting Requirements

l Storm Water Pollution Control Plan (SWPCP)

l Storm Water Discharge Permits

l Inspection and Sampling

l Enforcement

Key elements of the code include the requirement for permit holders to submit their SWPCP and monitoring results

to the City, the authority for the Director to adopt administrative rules, make inspections, and undertake enforcements.

Memorandum of Agreement

The City entered into a MOA with the DEQ in March 1994. The MOA delineates the responsibilities for the

implementation of the program between the two agencies. The MOA also prioritizes the implementation of the program

to address those facilities that are of most concern first. Key elements of the City’s responsibilities include:

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l Development of an inspection and monitoring program

l Informing DEQ of any new or existing facilities that require a permit

l Enforcement of City Code

Key elements of DEQ’s responsibilities include:

l Issuance of NPDES Industrial Storm Water permits upon referral or approval by the City

l Denial of permit applications for process wastewater discharge into the MS4

l Enforcement where the City lacks authority

Inspections and Monitoring

The section responsible for the implementation of the program is an autonomous work group. It is housed in the

Source Control Division, which includes the pretreatment program. In November 1994, two inspectors were hired to

implement the program under an existing supervisor. DEQ, which had been issuing permits since September 1992,

provided a list of facilities with stormwater permits. A letter was sent to the permit holders requesting that they submit

their SWPCP and all monitoring results. The letter referenced the MOA and included code citing the City’s authority.

Inspections were prioritized based on problematic outfalls as determined from information gathered in the Part 1 and 2

application process.

Inspections are usually scheduled in advance with the facility operator but can be performed without notice.

Inspection forms are filled out during the inspection and any readily noticeable issues addressed during a post inspection

meeting. Technical assistance is provided and information on Best Management Practices given in the form of verbal

suggestions and reprints. Facilities are also evaluated for the presence of illicit discharges. All inspections are followed

up with correspondence outlining the findings of the inspection and expectations of the industry. Any item where the

industry is not in compliance with the permit is highlighted with a deadline to meet compliance before escalating

enforcement is pursued. It is the goal of the program to perform annual inspections, at a minimum, of all permitted

facilities.

Industries are also inspected if they are identified as potentially needing a permit. These facilities are identified

through a systematic search using storm water outfall basins prioritized based on problematic outfalls. The basins are

delineated for drainage, the industrial facilities identified within the basin using our database, and facilities selected by

SIC Code. Inspections are also performed in response to referrals, drive-by% complaints, and responses to an industrial

survey performed in support of the pretreatment program. Prior to an inspection, building records, existing files from the

pretreatment program, and plumbing records are reviewed.

Stormwater sampling of permitted facilities is performed by collecting grab samples at the sample point(s) identified

in the facility’s SWPCP. Analyses are performed by the City lab. This sampling does not relieve the facility of its

stormwater sampling responsibilities. Files are developed on the facilities and maintained separately from the

pretreatment files. An electronic database has been developed and is used by both pretreatment and storm water staff.

Enforcement

Enforcement capability was developed in City Code. Where the City does not have enforcement authority, it seeks

voluntary compliance and refers enforcement to the permitting authority when necessary.

Funding

The program is entirely funded through a surcharge on the storm water fee for industrial and commercial accounts.

The storm water fee is currently based on impervious area. This surcharge also funds portions of other programs that

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have work related activities because of industrial and commercial storm water discharges. The current staffing level is

one supervisor and three technicians. Program costs amount to approximately $280,000 per year. This is primarily

composed of salaries and benefits, but also includes approximately $25,000 for sample analyses The budget also

contains funds for the development of BMPs and educational materials.

Findings

Legal Authority

It is essential that legal authority be developed in order to be able to implement and support a municipal program.

However, what is contained in the enabling legal authority (code) can vary drastically. It is important that the municipal

permit holder review the NPDES Industrial Storm Water permit to determine its adequacy in meeting the municipal permit

requirements. Most industrial storm water permits are general permits and they may not adequately address issues for

which the municipal permit holder is responsible.

For instance, if the municipality is responsible for meeting TMDLs for a particular water body, the industrial permit

may not even require that the facility monitor for these pollutants in its discharge. Provisions should be placed in code

that allow the municipality to require the facility to conduct this monitoring. Another example would be the requirement

to submit SWPCP and monitoring results to the municipality if this is not included in the permit. Nothing in federal

regulations prohibits the municipality from requiring additional controls beyond the permit requirements. A review of the

industrial stormwater permits can help identify elements that should be included.

Another provision that should be considered is the ability of the municipality to require a facility to obtain a permit.

Currently, federal regulations base the requirement for a permit on SIC Code and exposure. There is a caveat that allows

the permitting authority to require a facility to obtain a permit regardless of its SIC Code if that facility is impacting water

quality. However, this could require that the municipality undertake sampling and additional work to prove an impact.

This reduces the efficiency of the program in terms of resources and uniformity. It may even be necessary to include

provisions in the code that allow the municipality to develop its own permit. Such a tactic is time consuming, however,

and could create confusion for the regulated community.

Memorandum of Agreement (MOA)

The MOA should be developed to clearly outline the responsibilities between the permitting authority and the

municipality. Language should be broad enough not to constrict how the municipality implements the inspection and

monitoring program. This allows the municipality to alter the program as information is obtained from inspections without

having to alter the MOA. Probably the most important element of the MOA is the delineation of enforcement. Since the

municipality does not have authority to enforce permit conditions, language should specify that the municipality will enforce

applicable requirements of the Code and seekvoluntary compliance where it has no independent enforcement authority.

If compliance is not obtained using these methods, enforcement would be referred to the permitting authority.

Inspections

The City has placed the responsibilities for implementation of the program within the Industrial Source Control

Division. The section also houses the pretreatment program. It was felt that the responsibilities needed to be separate

because of the large number of facilities that are to be addressed. The City has over 24,000 commercial and industrial

facilities. Of these, nearly 3,000 have the SIC Code that potentially places them in the permitting program. In addition,

a Stormwater Work Group is responsible for addressing other discharges to the MS4, such as pumped groundwater,

boiler blow-down, water supply line flushing, washwater, and others.

For the City’s situation, this arrangement has worked very well. The Work Group is able to develop expertise in the

area while having access to existing information from the pretreatment program. Other municipalities have adopted this

approach while others have incorporated the responsibility into the pretreatment program or other existing programs

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including fire and safety inspections. The municipality needs to consider several items when determining who will be

responsible for implementing the program.

. The number and type of industries

l Existing oversight of the industries (pretreatment, hazardous materials,. . ,)

l Existing programs within the municipality

If the municipality decides to place the responsibility in a Work Group that is not dedicated for this purpose, it needs

to ensure that adequate resources exist to implement the program and meet the conditions of the MOA. The stormwater

program may not be the priority of the assigned work section and if resources become inadequate, this work may be

viewed as low priority and may not be addressed at the level that makes it effective.

The City has developed several “partnerships” to expand the inspection program. Informational flyers and a poster

were developed for county sanitarians to use when they inspect restaurants. A simple storm water checklist was

developed for City commercial recycling staff to use when inspecting retail establishments. In both of these cases, it is

important to note that the facilities targeted would not ordinarily be inspected for storm water issues (unless a complaint

was received) and that any issues of consequence would be addressed by storm water staff.

Permits

The DEQ has been issuing permits since September 1991. When the City took over administration of the permits

in the fall of 1994, 63 facilities that discharged to the MS4 had permits. Since that time, an additional 65 facilities have

been identified through inspections of non-permitted facilities. Non-permitted facilities are inspected based on SIC Code

and prioritized by outfall basins that have been identified as problematic. This approach was necessary due to the large

number of industries within the City that have the SIC Code included in the federal regulations. To perform a general

survey of all facilities would have generated much more work than resources allowed. Each site would have to be

evaluated prior to the issuance of a permit as the City is a mixture of combined sewers, sumps, and separated storm

sewers. Staff members spend a considerable amount of time determining where stormwater drainage discharges. A

municipality may be able to utilize this approach if the industrial base is smaller. Federal guidance states that a systemwide approach to establishing priorities for inspections should be developed.

Based on inspections of non-permitted industries to date (approximately 15% require a permit), and the remaining

facilities that require inspections, it is estimated that an additional 50-100 facilities will be permitted. Based on these

numbers, only 25-30% of facilities requiring a permit had applied when the City took over administration of the program.

However, a large percentage of the facilities not requiring permits still had issues that needed to be addressed or were

given BMPs that they were requested to implement.

SWPCP

The original general permit developed by DEQ did not require that the permit holder submit the SWPCP. When the

City took over administration of the permits, the plans were to be submitted using provisions of the City Code. Over 50%

of the facilities (33 of 63) had not developed a plan within the 180 days allowed in the permit, and of these, 14 (22%) had

not even developed a plan. It is imperative that the municipality includes provisions in the code to obtain these plans if

the provision does not exist in the permit. The requirement to submit the plan allows the City to track its development

and review the plan prior to an inspection. Currently, only 5% of facilities have not met the requirement to develop the

plan in the required time period.

Unfortunately, there is no requirement in the permit that the plans need to be approved. As long as they contain the

necessary elements required in the permit they would be in compliance. This has proven problematic in the quality of

some plans. It also restricts the City’s ability to require that the facility implement certain pollution control activities. This

emphasizes the need to include these provisions in the legal authority. The City has taken the approach of strongly

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suggesting that certain activities be implemented and incorporated into the plan. Once it is in the plan, it becomes part

of the permit and provides a mechanism to require the facility to implement these measures. The City is then able to take

the position of providing assistance in evaluating compliance with the permit. By noting these deficiencies and seeking

voluntary compliance, the City believes it is assisting the industry in meeting the conditions of their permit and benefiting

the environment through the implementation of the SWPCP.

Monitoring

When the City took over administration of the program in 1994, monitoring results were requested from permitted

facilities. Nearly 60% (36) of the facilities had not performed the required monitoring for the previous year. Of these, 22

had not taken the required two samples, while the remaining 14 did not perform the complete analyses. Of the samples

taken, 30% violated standards in the permit. Within the first year, the City was able to raise compliance on sample

collection to over 80% and reduce violations of standards from 30% to 23%. Currently, over 90% of the facilities are in

compliance with sample collection. It is more difficult to compare compliance with standards because a new permit was

issued in 1998, that includes benchmarks for metals that were not in the original permit.

Monitoring results have limitations because they are grab samples taken from a discharge that is short-term in nature

and highly variable. However, they can be used as a tool to measure effectiveness of BMPs and to identify sources of

pollutants. Based on sample results, the City has identified several classes of industries that pose significant pollution

concerns. These are, in order:

l Automotive recyclers (SIC Code 5015) - metals, oil and grease;

l Recycling industry (5093) - metals, oil and grease;

l Transportation facilities (various 4000) - metals, oil and grease, TSS;

l Heavy manufacturing (33~-, 34--) - metals;

l Food industry (20~-) - TSS, BOD, oil and grease.

Other SIC Code groups either represent a lower threat as a whole or are not present in the MS4. The City is now

using this information to reprioritize their efforts in identifying industries that require a permit. While the City is still

pursuing efforts based on outfalls, they are also developing a parallel effort to inspect all the facilities in these classes.

In addition, investigation efforts by the City identified the Wholesale Distribution of Construction Equipment (5082) and

Heavy Construction Equipment Rental (7353) as significant sources of pollutants. These classes are not included in the

federal regulations, but any municipal program should evaluate these facilities.

Enforcement

Enforcement capabilities have been developed in code for those discharges to the MS4. However, the City does not

have enforcement capability on permit provisions. The City must seek voluntary compliance and refer those matters to

the permitting authority for which they don’t have enforcement capability. This has worked to date, but requires

coordination between the City and DEQ. When seeking voluntary compliance, the City uses the threat of referral to the

permitting authority or third party lawsuits to obtain compliance. To make this effective, the permitting authority must be

ready to follow up with enforcement upon the municipality referral.

Funding

As with a number of environmental programs, especially regarding storm water, it is very difficult to measure the

cost/benefit until the program has been in place for a period of time. Costs have been identified, and certain benefits have

been realized. Compliance with permit conditions, for both industry and the City, have been, for the most part, met.

However, has this resulted in a benefit to the environment? City data have shown that industrial land use areas have

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significantly higher concentrations of pollutants than other land uses. Whereas the industrial land area in the MS4 is only

4%, it accounts for 11% of TSS, 15% of oil and grease, and 24% of metals. It would reason that a program aimed at the

highest concentration of pollutants would produce a good return on the investment, Another benefit of the program has

been the identification and removal of non-stormwater discharges. Approximately 15% of the inspections have identified

non-stormwater discharges, primarily washwater, that were of concern.

Conclusions

The development of a program to monitor and control pollutants from industrial facilities is not one of the six BMPs

that Phase II permit holders will be required to be developed. This may be due, in part, to the assumption that all

industrial permits would be in place because of Phase I requirements. However, our efforts have shown that only25-30%

of the industries requiring permits had applied prior to the administration of the program by the City.

If a municipality decides to develop and implement a program, it is recommended that it utilizes the accomplishments

of Phase 1 applicants. Phase 1 applicants can provide inspection forms, BMPs, MOAs, code language, and other

necessary components to develop the program. They can also share results of their work to help prioritize the efforts of

the municipality and help decide how to incorporate the work into existing programs. A municipality may also become

a co-applicant with Phase 1 permit holders. If this occurs, the applicant will become subject to an industrial control

program but may be able to utilize the existing program of the permit holder.

If a municipality does not develop a program, it is recommended that it at least work with the permitting authority to

identify who has a permit and the status of their compliance. The municipality should also evaluate the industrial base

in the MS4 and provide this information to the permitting authority if it identifies a facility that may be subject to the

program. It may be prudent to incorporate these activities into the illicit discharge elimination program, which is a

requirement of the permit. Whatever the municipality chooses, it needs to understand that it is ultimately responsible for

discharges from its MS4.

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Lessons Learned from Three Watershed-Sensitive Development

Demonstration Projects in the Great Lakes Basin

Sarah Bennett Nerenberg

The Conservation Fund

Great Lakes Office

Chicago, Illinois

Introduction to The Conservation Fund

The Conservation Fund (TCF) is a national, non-profit conservation organization that purchases and protects land

- more than 1.6 million acres since 1985. TCF also assists local communities, private landowners and government

agencies with programs that balance conservation with economicdevelopment. TCF works with communities to improve

water quality, build sustainable economic opportunities, and develop leadership skills, activities that put it at the forefront

of conservation across America.

TCF has been active in the Great Lakes Basin since it opened a regional office in 1995. The initial focus of its work

was the Great Lakes Watershed Initiative. This basin-wide effort was designed to raise the local visibility of the nonpoint

source water pollution issue. The Initiative adapted many of the innovative solutions showcased in the National Forum

on Nonpoint Source Pollution. TCF worked with many local partners to launch a network of community-based projects

addressing nonpoint source water pollution in urban and rapidly urbanizing areas in eight states and Canada. The

Initiative was conducted in partnership with the Council of Great Lakes Governors with major funding from the Great

Lakes Protection Fund and Kraft Foods.

TCF expanded several projects as an outgrowth of the Initiative including the watershed-sensitive development work

outlined in this paper and a sustainable development effort in Michigan. In Michigan, TCFfacilitates a broad, communitybased sustainable development effort in the Saginaw Bay watershed. The goal of the initiative, which engages local

businesses, community groups, and government agencies, is to better link the environmental and economic well being

of Saginaw Bay communities in order to sustain and improve the region’s overall quality of life. This year, the project

received the National Award for Sustainability from the President’s Council for Sustainable Development and Renew

America.

Introduction to Conservation Development Project

Currently, TCF is targeting one of the remaining threats to natural resource quality, enhancement, and preservation

in urbanizing areas - conventionally designed subdivisions. In partnership with local developers, community groups,

and government agencies, TCF is working in the Great Lakes Basin on the Conservation Development project. This

project is designed to demonstrate the environmental and economic benefits of watershed-sensitive design through a

series of model developments. In particular, we are working to demonstrate the benefits of watershed-sensitive siteplanning and best management practices that reduce impervious cover and conserve open space. The current model

projects are being developed in Huron, OH, Germantown, WI, and Niles, Ml. The George Gund Foundation and the

Great Lakes Protection Fund have provided major funding for this project.

We define watershed-sensitive development to include: open space design, significant reduction in impervious

coverage, natural stormwater conveyance and storage to the greatest extent possible, and appropriate construction

mitigation measures. Watershed-sensitive design can be used to build the same number of houses and still preserve

a significant portion of the subdivision’s original landscape. These open spaces serve important community and

environmental functions. Agricultural land can be farmed, residents can enjoy recreational and aesthetic benefits, and

important natural areas and systems can be preserved. Alternative designs also reduce the amount of impervious cover.

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Techniques including narrower streets, porous surface parking areas, stream buffers, and open channelsforstormwater

conveyance minimize runoff from new development and its negative impacts on water resources.

When evaluating potential conservation development projects, The Fund considered the following criteria:

l Local community must be interested and open to new techniques, including flexibility on zoning and subdivision

code issues;

l Property already slated for development and conventional development would have significant negative impacts

on the site itself or adjacent natural resources;

l Project partners represent one of the dominant development paradigms in the Great Lakes (i.e., professional

developer building homes in farm fields, lay developer seeking to hold and protect family or other special lands,

government agency seeking to encourage sound practices); and

. Project site is suitable for demonstrating broad array of site design techniques and best management practices

(BMPs).

Through TCF’s work in the Great Lakes, we gathered many lessons-learned that may be applied to other regional

and national efforts, This paper will review many of these lessons with the hope that other communities and

organizations will be able to benefit from our experiences. The paper is organized into the four sections listed below:

I. Overall Lessons Learned

1. Not “One Size Fits All”

2. Measurable Criteria for Watershed-Sensitive Development

3. Adequate Oversight and Inspection

4. Incentive System Needed

5. Relationship to Other Smart Growth Movements

II. Lessons Learned about the Development Process

1. Pace of Development Often Incompatible with Innovative Site Design

2. A Greater Initial Investment in the Baseline Information is Necessary

3. Initial Cost of Watershed-Sensitive Developments

4. Deed Restrictions

5. Need Additional Lay Developer Education

6. Aesthetics Do Not Equal Ecology

III. Lessons Learned about Engineering/Site Design

1. Educate the Engineers

2. Lot Size Often Dictated by Septic Issues

3. Need Hard Science

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IV. Lessons Learned about Working with Communities

1. Community Initiative

2. Local Official Knowledge Varied

3. Strong Local Partner is Key

4. Final Lessons Learned

Overall Lessons Learned

Not “One Size Fits All”

The approach used to create a watershed sensitive development must be tailored to the individual, organization, or

developer creating it. The assistance needed by a private landowner that is seeking to preserve portions of family lands,

for example, is quite different from that needed by a professional developer. We found that the models we developed

need to take the different skills and goals of the project’s initiator into account very early in the process. For example:

Lay developers (i.e., the individual landowners), not surprisingly, need help with the business aspects of the project,

and are more inclined to make frequent changes to the preliminary site plan and architectural style of the development.

These changes often reflect something the developer has “just learned” or “just considered.” These new ideas can add

value to the project, but they also require the technical assistants (e.g., landscape architects and engineers) to be more

patient, more flexible, and firmer than they might be with professional developers.

Professional developers demand immediate turnaround on requests for assistance, and are looking for “the facts”

on what is required to make a development watershed-sensitive. They can be somewhat impatient with the notion that

there are not a fixed and specified set of best management practices and site design practices that, if employed, will

“always” result in an “environmentally friendly” development.

Measurable Criteria for Watershed-Sensitive Development

As we began to design the model projects, it became apparent that there were no specific criteria available to

measure the benefits of the watershed-sensitive design. A tool was needed to encourage developers to fashion

environmentally friendly site designs, to help communities add flexibility to their local ordinances, and to provide a

standard that can be understood by both homebuyers and existing community residents.

In response to this, TCF developed the Conservation Development Evaluation System (CeDES) as a rating system

to evaluate a conservation development over the development’s lifetime with emphasis on water quality and landscape

impacts. The purpose of CeDES is to encourage developers to think about environmental concerns earlier in the

planning process and to provide consumers and communities with a means of assessing the impact of better site design

practices. It was developed with input from over thirty national professionals skilled in planning and evaluating

conservation developments. It may be viewed at http://www.conservationfund.org/conservation/sustain/gloindex.html.

Adequate Oversight and Inspection

One of the biggest challenges is ensuring that the contractors are building in an environmentally responsible manner.

Even if the developer is committed to minimizing the impact of the development on the environment, if contractors are

not educated and committed it may not happen. This is a challenge for many local agencies and municipalities who have

limited staff for constant inspections. Even if the communities have ordinances that require construction erosion controls

etc., without constant inspection many contractors do not follow the requirements. The nonpoint source pollution from

construction, especially the sediment loadings, can negate any benefits from the alternative site design. One

recommendation is for the community to require that an environmental inspector be hired specifically for the site. The

inspector may be from a consulting firm or from a local Soil and Water Conservation District.

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Incentive System Needed

We expect that this process will proceed much more quickly in communities that have recognized the threats

conventional developments pose and have begun developing strategies to address them. In order to expand

conservation development practices to a broader constituency, state or county agencies may need to develop incentive

programs that prompt local developers to undertake these projects. With each community, we encouraged the creation

of incentives for watershed-sensitive development. These included density bonuses for the developer through credits

for land preservation and minimization of impervious coverage. We also investigated the use of the Clean Water Act

State Revolving Fund (SRF). Among other uses, these funds are used to reduce nonpoint source pollution and could

encourage watershed-sensitive development. The State of Ohio has successfully used the SRF for this purpose and

we hope to pilot the same use of the SRF loans in other states. Incentives such as Ohio’s loan program, coupled with

the higher financial returns these developments are expected to generate, are making watershed sensitive developments

more the norm in the Great Lakes Basin.

Relationship to Other Smart Growth Movements

There are many “Smart Growth” movements currently being debating and promoted throughout the country.

Watershed-sensitive development is just one part of the equation. At times, we were challenged to show how this fits

into overall community sustainability efforts. The work that the National Site Planning Roundtable completed to develop

“Better Site Design” principles has been invaluable in demonstrating how these different movement can work together

(Center for Watershed Protection, 1998). We often say that watershed-sensitive development is one option for Smart

Growth but that a community needs to find the correct planning principles to work for their residents and issues. Those

in the Traditional Neighborhood Design (TND) movement challenge putting sidewalks only on one side of the street,

which we recommend for reducing impervious coverage. We also suggest that if sidewalks are on both sides of the

street at least one should be made of pervious materials. There also are environmental groups that challenge us for

encouraging greenfield development instead of infill development. Again, watershed-sensitive development is only one

option of many and if the market is going to demand suburban fringe growth, at least we can work with the communities

and developers to ensure that it is done with maximum possible protection and enhancement of the natural resources.

Lessons Learned about the Development Process

Pace of Development Often Incompatible with Innovative Site Design

The pace of development and the pace of government decision-making often are absolutely incompatible.

Developers with outstanding loans on land need to move quickly to ensure a development is economically viable.

Government agencies, on the other hand, are very concerned about the impacts of development, but move very

cautiously, especially when they are undertaking something new. The result is that it is easier for both government and

developer to create conventional, environmentally harmful developments than to do something better.

On the demonstration projects, TCF took special care at the outset of the process to communicate the timelines of

each participant to the other. In this way, we hoped to keep the parties from throwing up their hands and giving up. For

the region, however, we explored possibilities to get communities to adopt “fast track” approvals for watershed-sensitive

communities. The first need is to show municipal authorities that these developments deliver tangible benefits, then

we can help them develop mechanisms such as a streamlined review process and updated subdivision and

zoning ordinances that encourage their creation.

A Greater Initial Investment in the Baseline Information is Necessary

Before planning a watershed-sensitive development, fairly detailed baseline information including topography, soils,

and wetlands delineations is needed. Although developers hope that they get enough of the baseline site information

before beginning design work, inevitably the risk/benefit of doing extensive baseline work (e.g., soil borings) may

preclude the developer from getting all of the necessary baseline data. The common practice is to use “engineering

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judgment” based on existing data and extrapolation to the rest of the site. Unfortunately, especially when the drainage

plan is an integral part of the initial site design, relying on “engineering judgment” simply is not sufficient. For example,

on the Ohio site we relied on the existing soils information to design the swale system. After presenting a preliminary

site plan, the developer discovered through additional research and sampling that the available soil information did not

accurately represent the existing soil conditions and the drainage plan had to be reconstructed.

Initial Cost of Watershed-Sensitive Developments

Planning and developing a watershed-sensitive development takes time and costs money. Both lay and professional

developers often underestimate these initial costs. Professional developers often leave site planning to their engineers.

The engineers typically obtain a wetlands delineation and examine soil and topography maps, but do not evaluate the

site from a watershed or ecological perspective. Although lay developers may be more familiar with the special features

of their properties than professional developers, both need help to catalog all the features and to understand the site’s

role in the surrounding landscape. Quite reasonably, professional developers often are unwilling to undertake these

expenses until they have a sense of the project’s scale and niche in the market. We believe, and existing watershedsensitive developments indicate, that the costs of evaluating a property from an ecological and a watershed perspective

will be recovered when the development is sold out.

Deed Restrictions

The deed restrictions (i.e., covenants, conditions, and restrictions) necessary to ensure that the development will

continue as a watershed-sensitive development in perpetuity are a lot more extensive than typical deed restrictions.

Early in the process, sample restrictions for various developments should be presented to the developer and to the

community so that they understand the consequences of using some of the watershed sensitive techniques. The

developer will gain an appreciation for the long-term commitment necessary for a successful development and local

officials may be put at ease when they recognize that major additional responsibilities (e.g., swale maintenance) rest with

the homeowners association and not the local government.

Need Additional Lay Developer Education

Private landowners need to be assisted and educated through the process. Although these initiators often have a

deeper environmental commitment than professional developers, they often do not understand what kinds of activities

on their properties will have negative watershed impacts. For example, on one of our projects, the lay developer

suggested that a pond be built each time an area of low-lying ground is found to be wet most of the year. Once informed

about the relationship of these areas to more prominent wetlands on the site, the developer agreed to treat these areas

more appropriately (i.e., preserving and enhancing the existing wetlands). The professional developers understand

stormwater and wetlands issues better because they operate in the regulatory arena. The lay developers may need to

be educated about the significance of these issues and other issues that are common knowledge to professional

developers.

Aesthetics Do Not Equal Ecology

Another aspect of landowner education is the principle that aesthetics do not equal ecology. Just because a

development preserves or creates attractive green spaces does not necessarily indicate that it is not harmful to the

surrounding watershed. Accordingly, the criteria we developed for watershed-sensitive development (see discussion

above under Measurable Criteria) incorporate appropriate baseline evaluation of the site to insure key resources are

protected, and a thorough analysis of the stormwater impacts after development.

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Lessons Learned about Engineering/Site Design

Educate the Engineers

If any of the county, township, or city engineers are not comfortable with the techniques being used, they can turn

down the project at any point in the review process. In all three of our projects, the “old-timer-” engineers were extremely

conservative and feared change more than any other local officials. We found that the developers’ engineers need

constant oversight and education to design the sites using the watershed-sensitive techniques. Unfortunately, without

a broad effort to educate engineers, they will have to be educated one community or county at a time. Once these

techniques become more commonplace, we assume that such a great initial effort will not be necessary.

Lot Size Often Dictated by Sepfic Issues

Wastewaterissuesoften control the form, location, and economicfeasibilityof a new residential subdivision. In many

parts of the Great Lakes region, heavy clay soils strictly limit the functioning of conventional septic systems. For this

reason, lot size is frequently dictated by septic issues as much as by local zoning. Although there are some alternate

systems (e.g., constructed wetlands and community systems) being piloted and used in the region, local health officials

are very cautious about permitting them. This caution arises both from concerns about their technical functioning and

about long term maintenance issues. Communities already feel burdened by the need to monitor individual septic

systems. They are skeptical about a homeowner association’s ability to reliably maintain a community treatment system.

Wastewater treatment issues should be considered up front in evaluating the feasibility of clustering homes on a

particular site. If a public sewer does not serve the site, clustering probably will not work as well (i.e., the individual lot

sizes will not be able to be reduced as much). There is the possibility of placing the leach fields in the common property

to increase the overall open space percentage.

Need Hard Science

Although there is a great deal of national literature detailing watershed-sensitive development techniques, there is

not a lot of research documenting the extent of the water quality benefits they provide in the field. The Center for

Watershed Protection (CWP) recognizes that there is a lack of water quality monitoring data that evaluates the

techniques in varied site conditions and is working to develop and encourage more studies. Through consultation with

the CWP, the Northeastern Illinois Planning Commission, and the Wisconsin Department of Natural Resources (WDNR),

we found that funding for long-term monitoring of these techniques is scarce. Without this data, many of these

techniques may be challenged successfully by skeptical local officials. With the assistance of Old Woman Creek

Estuarine Research Reserve, one of our local partners, we are monitoring the water quality at the Ohio site. We hope

that they will be able to continue the monitoring after our grants are over. We also are working with the WDNR to secure

funding for long-term water quality monitoring at the Germantown site. It is our hope that this information will continue

to back up many of the claims of watershed-sensitive development and that funding will continue to support these efforts.

Lessons Learned about Working with Communities

Community Initiative

Without community buy-in and interest in these concepts, even the most enlightened developer is not going to be

able to get a project approved. When we first started this project, we thought that the developers were going to be the

“hard sell.” In two out of three of the communities, it actually has been the communities that needed more education.

In the Huron project, the developer was sold on many of the alternative site design techniques until he kept getting

negative feedback from the township board. This site was chosen because of the commitment of the developer and the

obvious benefits to the surrounding water resources. What was not realized was how much resistance there would be

in the political arena. At this project, we had several informal meetings with local officials prior to presenting a conceptual

plan, but because the process was developer-initiated, they continued to be resistant throughout the process.

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Local Official Knowledge Varied

Municipal, county, and state officials with similar regulatory responsibilities often have very different views about the

appropriateness of new techniques. Although there are no hard and fast rules about who is likely to be more

progressive, disagreements are common and a primary cause of frustration among developers.

As development is now regulated, it is more expensive and time-consuming for a lay or professional developer to

create a watershed-sensitive development. The only way for a developer to address this situation is to inform local

regulators and planning officials about the project early on, and to involve them in the process Unfortunately, this

involvement will probably not speed up the process for the individual developer, but after a few such projects are

launched, we believe the barriers for these kinds of developments will be lowered.

Getting everyone with a regulatory or permitting role on a project involved at the very beginning is absolutely vital.

If a project that includes techniques that have not been implemented in the region before gets too far along before all

the regulators and municipal officials are brought in, the “stranger to the deal” can feel left out and derail the project.

Much of this problem will be allayed once a few watershed-sensitive developments are built, but until then, developers

and regulators pushing for these practices need to make special efforts to get everyone to the table early. Of course,

this process increases the costs of doing the development initially, but it can keep it from falling apart after significant

site planning and related costs are incurred.

Strong Local Partner is Key

Throughout this project, TCF acted as a facilitator between the communities and developers and as a representative

of the silent third party, the environment. We believe that as each community begins to look at this type of development,

this third party is key to the success of a project. Although there are many merits to approaching communities as a

national organization, without a primary local partner who is well-versed in the trials and tribulations of the development

process (or willing to learn them), it is difficult to proceed. A preferable arrangement would be a local organization, such

as a land trust, leading the effort with support from a regional or national organization or technical assistance center.

A local organization will have a greater vested interest in and knowledge of the local environment, will know the local

officials and political and personal histories, and will be able to track and monitor the day-to-day activities surrounding

the development. In the long term, local land trusts may become a key player in this area. They understand land

conservation and watershed issues, frequently have close ties with both local landowners and local government officials,

and have some comprehension of the development industry.

Final Lessons Learned

Several realities of the development process that have little to do with the challenges of watershed-sensitive

development are important to mention for groups and communities considering this type of project. One is that the

personalities and reputations of the developers can make or break a project. On our project in Ohio, the developer

apparently had a “history” with several of the plan commissioners. Our partners in the community think that the plan

commission and the engineers were being unduly unfair during the review process. Also, one of the developers in

Wisconsin has a reputation for “low-end” development. Because of this reputation, the Village is afraid that the

developers will do their typical development in their town.

Another reality of the development process is that the Village Planner of Germantown estimated that 60% of

submitted development plans are reviewed by the plan commission and less than 50% of zoning requests are approved.

All of our projects include a zoning request because the current local ordinances do not include a provision for

watershed-sensitive development.

Conclusion

At all three of our model sites there are already signs of new developments being proposed with many of the

watershed-sensitive techniques. In Wisconsin, the developer was approached by neighboring communities to design
similar subdivisions. In Michigan, several local officials have stated interest in adding language in their new ordinances

that would encourage this type of development. In Ohio, our local agency partner, Old Woman Creek National Estuarine

Reserve, was approached by a developer who has been watching the process and is interested in using some of the

techniques at an adjacent site. While the review processes for all three projects have not been as easy as anticipated,

it is expected that the next round of developments will have an easier time because of the trailblazing work done before

them.

References

Arendt, Randall. 1997. Conservation Subdivision Design. Natural Lands Trust, Media, PA.

Center for Watershed Protection (CWP). 1998. Better Site Design: A Handbook for Changing Development Rules in

Your Community. Prepared for the Site Planning Roundtable, CWP, Ellicott City, Maryland.

Center for Watershed Protection (CWP). 1998. Consensus Agreementon ModelDevelopmentPrinciples to Protect Our

Streams, Lakes, and Wetlands. Prepared by the Site Planning Roundtable, CWP, Ellicott City, MD.

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Continuous Deflection Separation (CDS) for Sediment

Control in Brevard County, Florida

Justin Strynchuk, John Royal, and Gordon England, P.E.

Brevard County Surface Water Improvement

Viera, FL 32940

Abstract

In July 1997, Brevard County’s Stormwater Utility Program installed a new type of trash and sedimentation control

device called a Continuous Deflection Separation (CDS) unit. This was the first American installation to use the CDS

technology, which was developed in Australia. After installation, autosamplers were placed upstream and downstream

of the CDS unit and a year’s duration of sampling data collected. Monitoring has shown that the CDS unit has provided

an average 52% removal efficiency for total suspended solids and 31% removal efficiency for phosphorus.

Introduction

Stormwater sedimentation is a primary source of pollution to Florida’s Indian River Lagoon. Suspended solids and

turbidity reduce sunlight penetration in the lagoon which negatively impacts seagrass growth. Where land is available,

detention ponds effectively reduce most of the suspended solids from stormwater flows. When land is not available,

alternative, less effective, treatment methods must be used.

The CDS technology was initially developed in Australia to provide an effective method for trash and solids removal

from stormwater flows. The screening action within the unit provides for 100% removal of trash and particles down to

4700 microns. In addition, the unique circular design creates centrifugal action within the round concrete box which

propels suspended solids to the center of the box and down into the storage chamber.

Methods

The location chosen for the CDS unit installation was along a ditch at the north end of Brentwood Drive, south of Port

St. John. The drainage basin for this location was 24.87 hectares (61.45 acres) in area. This basin has Type A soils

along a sand ridge. The land uses are 24.87 hectares (6.7 acres) of roadway (US Highway l), 8.04 hectares (19.87

acres) of industrial park, 9.47 hectares (23.39 acres) of vacant land, and 4.65 hectares (11.49 acres) of commercial

property. The industrial area has a permitted stormwater system. A significant land feature is a 2.02 hectares (5 acre)

dirt parking lot, 152.4 meters (500 feet) upstream of the site around a local restaurant. This parking lot has a steep slope

and is composed of fine white base material. There is evidence of heavy silt buildup in the inlets and pipes downstream

of this parking lot, along US 1.

There is an earthen ditch running eastward 76.2 meters (250 feet) upstream from the project location. At the project

site, there is an existing 122 centimeter (48 inch) RCP driveway culvert in the ditch which discharges to a concrete

channel running 152.4 meters (500 feet) eastward to the Indian River. The time of concentration to the site is 63 minutes,

with a 1 O-year flow of 1,557.2 Usec (55 cfs) and mean annual flow of 1,177.g L/s (38.2 cfs). In Brevard County, the loyear storm is 20.1 centimeters (7.9 inches) of rainfall and the mean annual storm is 13.97 centimeters (5.5 inches) of

rainfall. There is no base flow at this location.

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A diversion weir 68.58 centimeters (27 inches) tall is placed in front of the 122 centimeter (48 inch) culvert so as to

divert flows over 254.8 Usec (9 cfs) around the unit. In 18 months of observations, the water level has risen over the

weir one time.

A 76.2 centimeter (30 inch) concrete pipe was constructed adjacent to the existing 122 centimeter (48 inch) pipe in

order to divert flows to the CDS unit. The 76.2 centimeter (30 inch) pipe enters the CDS unit tangentially to start the

circular flow within the unit.

The CDS unit consists of three circular, concrete chambers stacked on top of each other. The top chamber, where

the water enters the unit, has a 1.524 meter (5 feet) inner diameter and is 188 centimeters (74 inches) tall. The middle

chamber has a 2.44 meter (8 feet) inner diameter and is 127.54 centimeters (51 inches) tall. In the middle chamber is

a 1.524 meter (5 foot) diameter stainless steel screen matching the walls of the top chamber. The screen has 4700

micron holes to filter larger materials. The bottom chamber has a 1.22 meter (4 foot) inner diameter by a 1.22 meter (4

foot) tall sediment sump.

Water enters the unit in a clockwise rotation. When the water passes through the screen, it flows counter-clockwise

between the screen and outerwall until it reaches a 76.2 centimeter (30 inch) concrete pipe. This exit pipe is tangentially

placed for smooth exit flows. The elevation of the exit pipe rises 96.52 centimeters (38 inches) from the lower chamber

to the outflow channel downstream of the 122 centimeter (48 inch) culvert. This rise in elevation keeps the normal water

level in the unit near the top of the second chamber at all times. There is no base flow at this location.

The top of the unit is flush with the surrounding ground and has a 0.91 meter (3 foot) square, lockable, stainless steel

access cover. This feature allows for easy access with a vacuum truck for cleaning purposes.

The CDS unit was installed on July 17, 1997. Installation took two days with the precast structures. A large crane

was required to lift the chambers into place. A 4.57 meter (15 foot) deep hole was excavated for the structure.

In conjunction with the CDS unit installation, County forces cleaned the ditch upstream of the unit. Two days later,

a significant rainfall event occurred and 2,294 kilograms (6,600 pounds) of sediment from the upstream ditch wastrapped

in the unit. After that storm, the ditch was reworked and sod was laid. The sod greatly reduced the volume of sediment

washing into the unit.

Cleanouts were also performed on November 17,1997, removing 626.84 kilograms (1,382 pounds) of sediment and

2.88 meters (34 cubic feet) of trash and debris, and again on May 6, 1998, with 998 kilograms (2,200 pounds) of

sediment. The solids removed from the unit are taken to the Brevard County landfill for disposal. The volume of water

stored in the unit is greater than the vacuum truck capacity, so decanting is performed on nearby sandy soils to avoid

a second trip to the landfill for disposal.

Evaluation of the CDS Unit During Storm Events

The intent of the sampling was to evaluate the effectiveness of the CDS unit in removing pollutants from a storm

event prior to discharging stormwater into the Indian River Lagoon.

Five storm samples were collected at the CDS unit between April 1998 and March 1999. The storm events occurred

after dry periods ranging between 7 and 75 days. Protocol for this program dictated that if the sample collection devices

(autosamplers) were triggered at intervals of less than three days between storms, the samples were to be discarded.

This situation did not occur during the year, and near-drought conditions were observed in the sample area throughout

most of the year-long monitoring program.

Rainfall was measured at the sampling site by a tipping bucket rain gauge, and additional rainfall data obtained from

the Orlando Utilities Commission (OUC) power generating plant 5.6 km (3.5 miles) to the north of the CDS installation.

Review of the rainfall data collected indicates that the majority of the water passing through this BMP was from

precipitation falling on the upland, 18.72 hectare (46.25 acre) watershed. The variation noted in both coverage and

265
amount of rainfall helps illustrate the localized nature of the storms occurring along the Lagoon coastline. During this

sampling period, water flowing off the drainage basin contributed much more flow through the CDS unit than would have

been expected based on the rainfall recorded at the sample site.

Samples were collected through the use of automated storm water samplers; one at the inlet and another at the

outlet pipe of the CDS unit. All samples, associated blanks, and duplicates were collected in accordance with our statecertified Comprehensive Quality Assurance Plan.

The stainless steel intake strainers for the samples were mounted on the reinforced concrete pipe, slightly off center

bottom, and both angled away from the flow. This was to prevent the strainers from becoming silted over by sediments

and allow collection of representative water samples. Flow rates during the storm events were measured initially utilizing

water level meters (ISCO bubbler type) in conjunction with a go-degree V-notch weir, but eventually replaced with a

Doppler area-velocity flow meter which provides a more accurate flow assessment. Initially, two bubbler meters were

installed with both bubbler tubes mounted on the upstream weir. However, this led to difficulties in estimating just when

to trigger (time delay) the downstream sampler in order to collect samples from the same “plug” of water.

During the first three sample events, water levels recorded were correlated to flow, and the samples were manually

composited to give a flow-weighted composite sample from each sampler. Both inlet and outlet sample sets were

composited identically, in accordance with the EPA NPDES Stormwater Sampling Guidance Document (July 1992).

Discreet samples were collected for the fourth and fifth events.

It was intended that the third sample event would include a mass balance calculation. The CDS unit sump was

thoroughly cleaned utilizing a VAC-truck to ensure that the material collected was a result of the one storm to be

evaluated. Inlet and outlet stormwater composite samples were again collected, with the addition of a sediment (Table

1) and water column sample from the sump. Sediment depths were measured at five locations; four from the corners

of the lid opening and one in the center. Based on a depth of 13.21 centimeters, a sump diameter of 1.22 meters (4 feet)

and an estimated 1,410.6 kg/m3 (88 Ib/ft3), (based on previous sediment weight evaluation), approximately 217.3

kilograms (479.2 pounds) of sediment was collected in the unit from storm three. Based on the concentrations

measured, 126.07 grams (4.443 ounces) BOD 5, 33.587 grams (1.184 ounces) of metals, and 122.81 grams (4.33

ounces) of Total Kjeldahl Nitrogen (TKN) were removed.

Table 1. Sediment Chemical Analysis For Storm #l

Parameter Sediment Grab Duplicate

Grab

Arsenic 0.096 0.11

Barium 3.4 2.9

Benzo(b)fluoranthene 260 ND

BOD5 650 510

Cadmium 0.03 0.033

Chromium 1.1 1.1

Copper 1.2 0.95

Iron 220 260

Lead 2 2.2

Nickel 0.4 0.36

Silver 0.16 0.059

Total Kjeldahl Nitrogen 450 680

Total Phosphorus 79 230

Zinc 14 14

Notes:

Equipment Blank Water Yielded ND for all listed analytes.

*The benzo(b)fluoranthene mean value was calculated with the

RDL as the lower value for the duplicate.

Average Detection

Value Limit

0.103 0.069

3.15 0.14

250 240

580 2.7

0.0315 0.014

1.1 0.027

1.075 .0.027

240 0.55

2.1 0.041

0.38 0.069

0.1095 0.014

565 37

154.5 9.2

14 0.27

Units

MglKg

Mg/Kg

WKg

MS/Kg

M/Kg

WKg

Mg/Kg

WKg

%/Kg

Mg/Kg

W/Kg

WKg

MgJKg

MS/Kg

Only parameters with values above detection limit are listed. Many others were tested below detection limits.

266
For this third sample event, the upstream, or intake flowmeter bubble tube was mounted on the go-degree V-notch

inlet weir, as it was for previous sample events. The downstream bubbler, however, was moved and attached to the

downstream discharge pipe. This change was necessary to account for the lag time between when the first sampler

received flow at the beginning of the storm, the time required to fill the sump with 8,115 liters (2,144 gallons), and

discharge to flow past the second sampler several minutes later. The problem encountered with this revised setup was

that the upstream V-notch weir used to determine the flow was overtopped, allowing flow around and over it, preventing

an accurate flow measurement. This led to disparity in the estimation of actual flow through the unit. Due to the

questionable flow measurements, it was not possible to calculate the mass balance.

For the fourth sample event, an ISCO Doppler area-velocity flow meter was mounted in the bottom of the outfall pipe

of the CDS unit. Upon registering a water level rise of one inch, this unit triggered both upstream and downstream

autosamplers. The autosamplers were synchronized, collecting a bottle set in each ISCO at the same time. With this

methodology and placement, overtopping the weir, flow bypassing, and pressurization were no longer potential sources

of error. Since the samplers now triggered only when the sump was full, it was also somewhat easier to accept the

premise of “what went in, must have come out.”

Appropriate trigger points were selected in orderto allow sufficient water depth forthe velocity meter probe to operate

properly. We found that the Doppler area-velocity flow meter probes appear to function erratically when covered by less

than one inch of water, and believe that measurements taken when the water was at this depth are suspect. Two-bottle

sample sets were collected at sampler initiation, and at 1 O-minute intervals during the storm. During previous sample

excursions, samples were manually cornposited. Due to a high suspended solids content, (heavy particles including

sand) that rapidly settled in the sample container, it was questioned whether the composite samples were truly

representative of the solids collected. Therefore, discrete two-bottle sets collected every 10 minutes were sent to the

laboratory without being cornposited.

For the fifth sample event, two-bottle sample sets were again collected at sampler initiation, and at lo-minute

intervals during the storm. As with the previous sample event, sample sets were not composited but sent for analysis

as six individual, two-bottle sets. The sample bottles for bottle sets six were not collected due to insufficient water to

cover intake strainers, as the storm was not of adequate duration to produce the last 1 O-minute sample. Because of

numerous problems encountered in the previous storm event samplings, along with refinements in sampler setup and

flow measurement, the fifth storm sample event is considered the most accurate to determine what pollutant reduction

is provided by the CDS unit for that storm. The individual two-bottle sets showed the variation in pollutant loadings

throughout the storm event and the corresponding removal under the varying loads. Unfortunately, this was the lowest

flow storm encountered, which may account for higher than normal removal efficiency. Maximum flow was estimated

to be only 136 liters/set (2.16 gpm). The average pollutant reduction between inlet and outlet samples for this event was:

BOD5 53%, COD 52.6%, TP 36%, TSS 56%, and Turbidity 74.8%.

Sample results are presented in Tables 2 through 4 for the five sample events. Storm event 2 showed a 23%

reduction in turbidity, but no reduction in the other parameters. Storm 4 showed an increase in most parameter

concentrations between inlet and outlet that could not be attributed to resuspension due to a full sump, since the sump

had been cleaned prior to the third event. Data for these two storms are therefore suspect. For events 1, 3, and 5, the

average removal efficiencies for those parameters that showed a reduction were: TSS 52%, Turbidity 46.9%, BOD

34.2%, COD 35%, and TP 30.6%

After each sample event, field observations were made of the appearance of the sample jars, each containing a

water sample that had been collected at progressive ten-minute intervals throughout the storm flow. Outlet samples

typically appeared to be less turbid than the corresponding inlet samples, and also had less sediment on their bottoms.

An observation was also made of the water surface inside the CDS unit proper. There was typically a thick layer of

floating grass and other vegetation, an oil sheen, glass and plastic bottles, plastic sheets and bits, seeds and nuts, sticks,

and a surprising amount of Styrofoam cups and particles.

267
Table 2. Storm #l-#3 Test Results - Composite Samples

pH Total Turbidity BODS-Day COD Total

STORM 1

CDS Inlet

CDS

Outlet

Change

Percent

Reduction

s u

7.6

7.4

0.2

3%

Suspended

Solids

mg/l

220

110

100

50%

NTU

180

100

80

44%

Maximum flow rate = 5.488 literslsec (87 GPM, 0. 19 cfs)

Storm Duration = 67 minutes

Rainfall @ OUC 0.254 cm (0. 1 inch), @ SITE not recorded

STORM 2

CDS Inlet

CDS Outlet

PH

s u

8.4

8.2

Total

Suspended

Solids

mg/l

350

350

Turbidity

NTU

440

340

BOD&Day COD

mg/l mg/l

8.2

8.2

Change

Percent

Reduction

0.2 0 100 0

2% 0% 23% 0%

Maximum flow rate = 8.39 literskec (133 GPM, 0.3cfs)

Storm Duration = 68 minutes

Rainfall @ OUC 1.778cm (0.7 inch),.@ SITE 0.0762 cm (0.03 inch)

mg/l mgll Phosphorous

mg/l

28 150 1.4

23 110 1

5 40 0.4

18% 27% 29%

20

20

0

0%

Total

Phosphorous

mg/l

0.86

0.86

0

0%

STORM 3

CDS Inlet

CDS Outlet

Change

Percent

Reduction

PH

s u

7.6

7.6

0

0%

Total

Suspended

Solids(mg/l)

300

150

150

50%

Turbidity BODS-Day COD

NTU mg/l mg/l

110 12 71

86 8.2 53

24 3.8 18

21.8% 31.7 % 25.4

Total

Phosphorous

mg/l

1.3

0.95

.35

27%

Maximum flow rate = 149.75 literskec (2374 GPM, 5.29cfs)

Storm Duration = 113 minutes

Rainfall @ OUC 4.064 cm (1.6 inch), Q SITE 1.27 cm (0.5 inch)

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Table 3. Storm #4 Test Results - Discrete Samples

Set 1

@ initiation

BODS-Day

(w/l)

COD

@cdl 1

PR

WJ)

Total

Phosphorous

(w/l 1

Total Suspended

Solids

(mg/l)

Turbidity

(NW

Inlet 1

Outlet 1

Change

Percent

Reduction/Gain

2.1 2 8

5.4 2 7.8

+3.3 0 -0.2

+61% O’% -3%

Inlet 2 6.6 15

Outlet 2 7 18

Change +0.4 -3

Percent +I- +6% +17%

Inlet 3

Outlet 3

Change

Percent

Reduction/Gain

6.7 25

6.7 24

0 -1

0% -4%

Inlet 4

Outlet 4

Change

Percent

Reduction/Gain

6.3

NT

Na

Na

45

NT

Na

Na

Inlet 5

Outlet 5

Change

Percent

Reduction/Gain

5.6

6.4

+0.8

+13%

33 8 1.6

30 8.2 1.6

-3 +0.2 0

-9% +2% 0%

Inlet 6

Outlet 6

Change

Percent

Reduction/Gain

6

6.3

+0.3

+5%

39 7.9 1.6

33 8.2 1.5

-6 +0.3 -0.1

-15% +4% -6%

0.32 690 99

0.19

-0.13

41%

8.3 1.2

8.4 0.94

+O.l -0.26

+I% -22%

8.2

8.3

+O.l

+l%

1.2

1.5

+0.3

+20%

8.1 1.6

NT NT

Na Na

Na Na

t

Maximum flow rate = 60.30 literskec (956 GPM, 2.13 cfs)

Storm Duration = 55 minutes

Rainfall 0 OUC 2.794 cm (1 .I inch), @ SITE 0.006 cm (0.002 inch)

320 120

-370 +21

-54% +18%

1400 1800

1600 1000

+200 -800

+13% 44%

830 530

550 430

-280 -100

-34% -19%

330 200

NT NT

Na Na

Na Na

290 300

170 260

-120 40

41% -13%

220 120

270 230

+50 +I10

+19% +48%

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Table 4. CDS Storm #5 Test Results - Discrete Samples

BOD5-

Day

(w/l 1

COD pH

0-M 1 (SW

Total

Phosphorous

0-M)

Total Suspended

Solids

(Wl)

Turbidity

(NW

Inlet 1

Outlet 1

Change

Percent

Reduction/Gain

4.6 68 7.8 0.23

4.0 18 7.9 1 0.18

-0.6 -50 +.l -0.05

13% 74% 1 % 22%

10 51 7.8 1 0.25

3.8 23 7.9 0.18

-6.2 -28 +.I -0.07

62% 55% 1% 28%

13 55 8.2 0.3

4.7 33 7.6 0.18

-8.3 -22 -0.6 -0.12

64% 40% 7% 40%

9.9 53 9.2 0.35

3.9 29 7.7 0.18

-6 -24 -1.5 -0.17

61% 45% 16% 49%

9.6 53 9.4 0.29

3.4 27 7.6 0.17

-6.2 -26 -1.8 -0.12

65% 49% 19% 41%

53% 52.6% -% 36%

49 16

11 4.3

-38 -11.7

78% 73%

Inlet 2

Outlet 2

Change

Percent

59 38

19 6.9

-40 -31 .l

68% 82%

Inlet 3

Outlet 3

Change

Percent

Reduction/Gain

23 23

21 12

-2 -11

9% 48%

Inlet 4

Outlet 4

Change

Percent

Reduction/Gain

39 61

15 7.2

-24 -53.8

62% 88%

Inlet 5

Outlet 5

Change

Percent

Reduction/Gain

Average Percent

Change

35

13

-22

56

9.4

-46.6

83%

56% 74.8%

Maximum flow rate 0.136 literskec (2.16 GPM, 0.005 cfs)

Storm Duration =50 minutes

Rainfall @ OUC 1.016 cm (0.4 inch), @ SITE, 0.5842 cm (0.23 inch)

Conclusions

While none of the sample events were a perfect combination of a good flow and everything working right, the data

collected, and our observations, certainly indicate that the CDS unit is operating as intended and removing significant

quantities of debris and suspended materials prior to discharge to surface waters. It was quite impressive to prevent this

trash and sediment from washing out into the lagoon during a normal rain.

The phosphorus removals observed for the CDS Unit, as with any BMP of this type, will not have a high degree of

accuracy, due to leaching of nutrients from grass, leaves, and other organic debris. If there are no base flows, these

leached nutrients will be washed out with runoff and skew sample readings. A much more comprehensive analysis is

available in the library of the web site www.stormwater-resources.com.

Future Evaluations

More data are necessary to further evaluate this BMP. Due to the inherent inaccuracies in water quality sampling,

additional determination of the efficiency of this type of BMP could be made by conducting a mass loading and sediment

evaluation. Much of the sediment collected in this type of BMP is invisible to current testing techniques since it is

comprised of large particles that roll along the bottom of the pipe. Yet, known quantities of sediment are being collected.

270
A previous study of baffle boxes resulted in the same conclusion. Future sediment analysis from the CDS unit could

be compared to the baffle box data previously collected. Brevard County will be conducting a sediment evaluation at

three baffle box sites over the next 12 months that will provide additional comparison. As time permits, Brevard County

will also collect additional sediment data from he CDS unit.

271
Use of Automated Technologies in Watershed Management Planning

Lake County Stormwater Management Commission (SMC)

Libertyville, IL

Introduction

The Lake County Stormwater Management Commission’s (SMC) is working with many agencies to develop

comprehensive watershed plans. These watershed plans involve data collection and collation, problem analysis,

alternative solutions identification and action plan development. The watershed assessment includes hydrologic and

hydraulic modeling; floodplain and floodway mapping; and water resource assessment. As part of a watershed

management plan, one of the end results is to update floodplain maps and to map depressional storage areas.

Other end products of this effort include location maps of water resources, including wetlands and regional detention

sites, with identification of those needing preservation, enhancement or restoration. With this information, projects

can be prioritized and cost estimates determined in order to assist local governments in implementing the action

plans.

Lake County, Illinois is located in the northeastern corner of Illinois and is one of the fastest growing counties in the

country. The county has 61,000 acres of wetlands (12) and 400 miles of streams

and rivers throughout its 480 square miles. The combination of growth and the

need to protect natural resources is driving the Lake County Stormwater

Management Commission’s (SMC) comprehensive watershed planning efforts.

Plans are currently being developed for urbanizing watersheds between 2 and

50 square miles in area.

With limited personnel and funding, SMC is utilizing in-house computer

capabilities and staff technical expertise to save time and money as we increase

our ability to model and display watersheds. The Squaw Creek Plan is an

example of how SMC is currently utilizing automated technology for watershed

planning purposes. The Squaw Creek watershed is 25.5 square miles and is

75% undeveloped (includesagriculture, vacant and open space). The watershed

is 17.3 percent wetlands. TheNorthern Illinois Planning Commission forecasts

a 155% population change between 1990 and 2020. The Squaw Creek

Watershed is located in the western portion of the county and drains into Fox

Lake, on the Fox River.

Map 1: Lake County, Illinois, Sub-Watershed

SMC is integrating Geographic Information System (GIS) (2) technology with Computer Aided Design (CAD) and

the Army Corps of Engineer’s HEC-1 (10) and HEC-RAS (11) models to create an “automated” watershed closely

resembling the existing Squaw Creek watershed characteristics. SMC used a variety of vendor software packages that

include Environmental Systems Research Institute, Inc.‘s (ESRI) ArcView (1) and its Spatial Analyst and Hydrologic

Extensions, and Bentley’s MicroStation.

Data Collection

It is very important to determine the methodologies for collecting, calculating, and analyzing data early in the

automation process. Methodologies were determined for mapping floodplains, inventorying and analyzing water

resources (8), and estimating runoff water quality. The floodplain mapping variables included time of concentration,

precipitation runoff, stream storage, stream routing, sub-basin boundaries, and water surface elevations. Thesevariables

272
had to be determined before final data could be formatted and collated. We also had to determine how data could be

documented in the report early in the study process,

Since considerable map data was available digitally, it was economical to perform many tasks on the computer rather

than on hard copy. The Northern Illinois Planning Commission (NIPC) provided the digital land use map. Lake County

Map Services provided digital copies of the Soil Conservation Service (SCS) hydrologic soil groups (HSGs) map, hydric

soil map, United States Geological Society (USGS) orthophotos, Lake County Wetland Inventory boundary map, and

Lake County parcel boundaries. In addition to this digital data, SMC contracted to obtain 2-foot topographic contours,

detailed orthophotos, stream cross-sections, and field-surveyed hydraulically significant structures. Bridge and culvert

information and stream cross-sections were also delivered digitally from Illinois Department of Natural Resource’s (IDNR)

land survey crew using Global Positioning System (GPS) and conventional surveying. Photogrammetry and crosssection control points were collected in the field utilizing a GPS with accuracy of 1:50,000 horizontal and +/- 0.03 feet

vertical (5). Each USGS digital orthophoto map covers one quarter of a quadrangle and used 45 MB of computer

storage. The topographic maps weredelivered in GIS and CAD formats. Contracted data were delivered by square mile.

This created a reasonable size data file, including:

Two foot topographic contours and breaklines 1.2 to 3 MB per square mile.

Orthophotos 35 MB per square mile

Digital Elevation Model 1 MB per square mile

The cost for the two foot contours overlaid on an orthophoto varied between $2200 and $3300 per square mile.

Additional record drawings of hydraulically significant structures, such as road crossings and detention basin outlets,

were collected from county and state highway departments and local communities. The townships and communities

seldom had detailed information, so field investigations were undertaken, where necessary, using topographic mapping

to establish a reference elevation.

The water resources inventory included a stream assessment, wetland inventory, and a wetland restoration

assessment. The stream assessment data were collected in the field along with short community interviews. The stream

inventory used an existing methodology created by NIPC (8). SMC created a methodology to identify potential wetland

restoration locations.

Surface runoff water quality was estimated using typical measured pollutant loading data for several general land

uses. NIPC had an existing procedure that assigned non-point runoff pollutant loads to general NIPC land uses. The

typical pollutant loadings were entered into a worksheet so this procedure could be automated.

Creating Hydrologic and Hydraulic Data

Several hydrologic and hydraulic parameters and other data were used to analyze the surface water runoff and

generate floodplain boundaries. These included delineating sub-basin boundaries; determining a runoff curve number,

time of concentration and Clark’s coefficient of runoff for each sub-basin; calculating reservoir data; formatting HE&l

model; and creating HEC-RAS model geometry.

Sub-basin Delineations

The sub-basin boundaries were produced automatically using the following steps. First, a Digital Elevation Model

(DEM) was produced from photogrammetry by a consultant. A DEM is a list of equally spaced data points with a defined

easting, northing, and elevation. A spacing of the DEM points of 10 and 30 feet was evaluated. The lo-foot spacing

would slightly increase the accuracy of the automated sub-basin boundary’s but it used ten times the disk storage as the

30-foot spacing. Therefore, a 30-foot grid DEM was used to determine the sub-basin boundaries due to storage space

limitations. Second, the DEM was loaded into ArcView and converted to a DEM grid using ArcView’s Spatial Analyst.

Third, the flow paths and the preliminary sub-basin boundaries were created using ArcView’s Spatial Analyst and

Hydrologic Extension along with the DEM grid, which delineated 180 preliminary sub-basin boundaries in 2.5 hours.

273
Fourth, these preliminary boundaries were edited with the digital contour map in the background to better model storage

areas and road crossings. This editing entailed splitting basin boundaries and joining basins together to produce more

accurate boundary lines. Editing was performed on portions of approximately 50% of the preliminary sub-basins that

were automatically created and ultimately reduced the number of sub-basins. Edited boundaries were checked against

hard copy maps and a field investigation of storm sewers and field tiles. A check of maps and field investigation identified

three boundaries that needed additional modifications including the addition of one sub-basin. Finally, ArcView was used

to automatically calculate each sub-basin’s area and a sub-basin identification was assigned to each of the 140 subbasin areas.

Runoff Curve Number

SMC created a methodology to estimate precipitation runoff. This required converting SMC defined land use

categories to Soil Conservation Service (SCS) runoff curve numbers (RCNs) (9) using ArcView and Excel (6). RCNs

were calculated using the following sequence. First, the 1990 NIPC land use polygons were converted to SMC land use

categories based on land cover using 1996 orthophotos as a backdrop. Land cover was divided into six categories: 1)

impervious, 2) graded grass, 3) natural grass, 4) graded forest, 5) natural forest, and 6) agriculture. Typically graded

grass and graded forest land cover categories have increased runoff compared with their natural conditions as soils are

compacted and depressions are removed during grading. A SMC land use was created for the calibration year of 1996

and for the model year of 2000. Second, concurrently with the land use conversion, the digitally mapped soil numbers

were converted to HSGs using GIS queries. Third, the HSG map was intersected with the SMC land use categories to

automatically create a land cover map. Fourth, the land use categories table and a land cover conversion table were

joined so there was one RCN for each of the four HSGs.

Runoff Data

HEC-1 requires specific input data to generate runoff volumes for each sub-basin. The minimum input parameters

for each sub-basin were identification, area, the time of concentration (Tc), Clarks Coefficient of Runoff(R), and weighted

RCN. Sub-basin area was delineated as previously described.

The weighted RCN was determined in two steps. First, intersecting the finalized sub-basin boundaries with the

RCNs boundaries using ArcView. This splits the RCN polygons with the sub-basin boundaries. This calculation took

just twenty minutes. Then this table of RCN attributes for each sub-basin was exported from ArcView into Excel where

the weighted curve number for each sub-basin was calculated in one day.

In addition, each sub-basin requires a length and slope of travel to generate the Tc and R. To determine the length

and slope, a line with two points were needed, one upstream and one downstream. The line represented the direction

of runoff from the farthest ridge to the outlet of the sub-basin. GeoAnalytics, Inc., a consultant, created a program to

automatically generate a distance point 10% and 85% from the sub-basin outlet along this digitized line in 30 seconds.

The point locations along the line were determined by the methodology used to estimate Tc and R. These points were

queried individually with the DEM grid and checked against the topographic map to determine their elevation, which was

entered into a table, ArcView calculated all sub-basin line lengths in less than a minute. The stream line and its two

elevation points were associated with the sub-basin identification throughout this process. Next, the sub-basin

boundaries, the associated line, and two points were joined into one table and exported as a database file. This

database file was imported to an Excel worksheet where the slope, Tc, and R were calculated for each sub-basin.

Reservoirs

To model reservoir routing, the reservoir volumes were determined using ArcView and the 2-foot digital contours.

The reservoirs consisted of a series of polylines in ArcView after conversion of the CAD contour map. The polylines were

modified so they were completely connected and then converted to a polygon in ArcView. This documented the location

of every reservoir that was modeled explicitly, as not all reservoirs could be modeled within the scope of our project.

Second, the elevation for each contour was entered into a table. The topographic contractor now performs steps one

and two. After all the elevation polygons were created, ArcView calculated the area of the polygons with one command.

274
Finally, the elevation and area tables were opened in an Excel worksheet to calculate the elevation versus storage

relationship. This worksheet was referenced by the HEC-1 formatted worksheet described in the next section. Stage

versus discharge relationship was determined for each reservoir when data was available using HEC-RAS or HY-8.

Hydrology Model Development

All of this data was combined into one Excel workbook to generate the input needed for HEC-1. The sub-basin data

entry included: identification, area, weighted RCN, Tc, and R. Most sub-basins also needed reservoir or stream routing

data. An Excel worksheet was edited with HEC-1 formatted column widths so the data could be saved into a file that

the HEC-1 FORTRAN program can accept. Sub-basin data were entered automatically by referencing other worksheets

in the same workbook. Once the first sub-basin referenced the other worksheets properly, the first formatted sub-basin

data were copied to create another set of HEC-1 data for the next sub-basin. After the sub-basin identification was

entered for this new HEC-1 input data set, the remaining data were automatically retrieved in the worksheet and correctly

formatted, to avoid data translation errors.

Hydraulic Data

The stream cross-section data were initially generated in MicroStation. Each section was digitized as a series of

connected line segments that were exported to a comma-delimited file of easting, northing, and elevation which was then

imported into HEC-RAS’s “Import/Export Files for Geospatial Data.” The culvert and bridge data had to be coded in

separately. The channel stationing was determined automatically using Intergraph In-Roads. This procedure not only

provided data formatted to be exported directly in HEC-RAS, but also created a 3D map of the channel cross-sections

and stream centerline to document the model spatially using MicroStation and ArcView. The cross-section segments

had to be manually identified for use in the automated floodplain mapping.

Floodplain Development

Stream cross-sections and hydraulic structures were modeled using HEC-RAS to determine the water surface

elevation along the stream. ArcView’s Spatial Analyst Extension or Arclnfo could be used to delineate the floodplain from

the HEC-RAS output. Final maps were generated in ArcView.

The HEC-RAS generated water surface profiles were exported by HEC-RAS’s “lmporVExport Files for Geospatial

Data.” GeoAnalytics Incorporated, Madison, Wisconsin, imported this data into an Arclnfo project that uses a 1 O-foot

DEM grid. Arclnfo needs a line and an elevation for each cross-section to map the floodplain. The cross-section line

and its identification were created in MicroStation, exported as comma delimited points, and then referenced into ArcView

to create the cross-section line. The line with its cross-section identification was associated with the water surface

elevation. The grid was then “flooded” between the two cross-sections with a linear slope between the appropriate water

surface elevations. This creates a grid of the flooded area. For each flood profile that was to be mapped, a separate grid

of the flooded area must be completed.

Reservoirs, such as lakes, ponds, and depressions, that have their Base Flood Elevations determined using HEC-1,

were mapped automatically. The storage areas had the water surface elevation defined using HEC-1 then the grid was

“flooded” for all points at or below that elevation.

The flooded grids were then converted to polygons and “smoothed” in Arclnfo for use in ArcView. Last the polygons

were reviewed against the digital two-foot contours and adjusted as needed before final map production. Every reservoir

outlet had to be manually mapped between its outlet and the downstream reservoir or stream floodplain.

Water Resource Assessments

A water resources inventory was completed that included a stream assessment, a wetland inventory, and potential

wetland restoration site identification. All of the stream assessment data were collected in the field along with short

community interviews and entered into a database. Several key stream characteristics were mapped using GIS. The

275
stream inventory data were queried for specific stream conditions and key characteristics were mapped such as degree

of bank erosion or sediment accumulation.

A county wetland Advanced Identification (ADID) study was completed in 1992 prior to the assessment. One of the

criteria reviewed for each wetland was its storage potential, which was related to the area of the wetland. Querying the

spatial data for specified wetland areas and creating a new set of data easily identified these wetlands. The wetland

restoration and mitigation bank site identification methodology was developed by SMC in 1999. Several data sets were

queried to identify the former wetland sites that have the greatest number of characteristics necessary to make them

restorable and usable as a wetland bank. A less stringent set of criteria was used to define all former wetland sites with

restoration potential. The potential wetland restoration sites included all Advanced Identified (ADID) wetlands. Potential

wetland banking sites excluded ADID wetlands and restorable sites less than 20 acres.

Surface water quality ‘hot spots” were estimated using non-point pollutant loading rates for several general land uses

via NIPC methodology. Twelve pollutants were evaluated. The pollutant “hotspots” analysis employed land use,

impervious surface area, annual runoff coefficients, and storm sewer conditions as surrogates to determine the annual

pollutant loading by sub-watershed. The pollutant loading database was attached to the land use map database. It was

then mapped in ArcView resulting in 12 maps, one for each pollutant.

The watershed advisory committee and NIPC identified which level of pollutant loadings should be labeled as

detrimental. The pollutant load data were then grouped, using natural breaks in the data set, as low, medium or high.

These were mapped and queried to determine where water quality enhancement projects would be most beneficial and

highest priority.

Summary

The Lake County Stormwater Management Commission has invested a significant amount of time and funding in

developing the hardware, software, and database necessary to perform floodplain analysis. By making this commitment

and establishing the methodologies for manipulating data and analyzing watershed parameters, we have created a

powerful analysis tool. Mapping accuracy, display flexibility and a wide range of GIS analysis ability has been created

through this process. This technology coupled with other resource assessment efforts has created a strong foundation

for future watershed planning in this watershed. The technology is transferable and will be used throughout Lake County

as our agency resources allows.

References

Environmental Systems Research Institute, Incorporated (ESRI) ArcView, 1995, “Using ArcView GIS 3.0a” and “Spatial

Analyst”

Environmental Systems Research Institute, Incorporated (ESRI) ArcView, 1996, “Using the ArcView GIS Spatial Analyst”

Lake County Stormwater Management Commission, 1994, Watershed Development Ordinance

Lake County Stormwater Management Commission, 1998, General Conditions of Topographic Mapping

Lake County Stormwater Management Commission, 1997, Attachment A, Field Survey and Data Collection

Lake County Stormwater Management Commission and GeoAnalytics, Inc., Madison, WI 53704, 1998, Lake County,

Illinois Stormwater Management Commission, GIS Data Handling Procedures for Input into HEC-1

Lake County Stormwater Management Commission, Land Use to Land Cover Conversion Methodology

Northern Illinois Planning Commission, 1994, “Methods and Procedures for the Stream Condition Form,” from Appendix

A of Sequoit Creek Watershed Management Project.

276
Soil Conservation Service, Washington, DC, 1985, National Engineering Handbook Section 4 - Hydrology, PB86780494

U. S. Army Corps of Engineers, 1990 “HEC-1 Flood Hydrograph Package User’s Manual Version: 4.0”

U. S. Corps of Engineers, 1997 “HEC-RAS 2.0 River Analysis System”

U. S. Environmental Protection Agency, Region 5, Lake County Stormwater Management Commission, and Northeastern

Illinois Planning Commission, November, 1992, “Wetland Advanced Identification (ADID) Study, Lake County, Illinois”

277
Sediment and Runoff Control on Construction Sites Using

Four Application Methods of Polyacrylamide Mix

A. Roa-Espinosa

Urban Conservationist

Dane County Land Conservation Department

Assistant Visiting Professor

Biological Systems Engineering

University of Wisconsin-Madison

G.D. Bubenzer, Professor

Biological Systems Engineering

University of Wisconsin-Madison

E. S. Miyashita, Former Project Assistant

Biological Systems Engineering

University of Wisconsin-Madison4

Abstract

Fifteen small bare plots (1 meter x 1 meter) on a 10% slope were analyzed for runoff and sediment yield on a

construction site. A rainfall simulator applied 6.32 centimeters of rainfall per hour to each plot after a polyacrylamide mix

(PAM-mix CFM 2000*) treatment was applied. The following treatments: No PAM-mix applied to dry soil (control), PAMmix in solution applied to dry soil, dry PAM-mix application to dry soil, PAM-mix in solution with mulch/seeding applied

to dry soil, and PAM-mix in solution applied to moist soil. Each treatment was repeated on three plots. When a solution

of PAM-mix with mulch/seeding was applied to dry soil and compared with the control (no PAM-mix application to dry

soil), we found an average reduction of 93% in sediment yield. An average reduction of 77% in sediment yield was the

worst performing PAM treatment, and occurred when PAM-mix in solution was applied to moist soil. The application of

dry PAM-mix to dry soil reduced sediment by 83% and decreased runoff by 16% when compared to the control. Our

results show that regardless of the application method, PAM-mix was effective in reducing sediment yield in the test plots.

The ease of application, low maintenance, and relatively low cost associated with PAM make it a practical solution to

the costly methods being implemented today

Keywords:

Soil binders, soil erosion, polyacrylamides, flocculation, infiltration, water retention.

*Use of a product name is for the convenience of the reader and does not imply endorsement by the authors, Dane

County Land Conservation, or the University of Wisconsin.

Introduction

One effect of rainfall is the initiation of the erosion process where individual raindrops fall and impact the soil surface.

Soil detachment and particle transport by raindrop splash can lead to serious soil deterioration. Once soil is eroded and

transported by surface runoff to lakes, rivers, and streams, a degradation of the aquatic habitat occurs. Sediment is the

largest pollutant, by volume, in the State of Wisconsin (WDNR, 1994). In order to maintain a healthy watershed, it is

critical to control erosion and sediment yield.

Maintaining soil structure and aggregate stability helps control erosion by increasing infiltration and maintaining less

erodible-sized aggregates. Stable soil structures also help maintain a healthy environment. The use of polyacrylamides

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and polyacrilamide mixes (PAMs and PAM-mix) is a new tool to help maintain soil aggregate stability and reduce erosion

caused by surface runoff. Such materials can be applied at a rate of 20 to 30 Ibs per acre on construction sites, to

stabilize such sites against erosion until they can be permanently protected through vegetation.

Water-soluble polymers and water polymer mixes do not create aggregates when applied to soil. However, they can

stabilize existing aggregates when the aggregates are saturated with a solution of water soluble polymer mix. Increasing

the aggregate stability with polymers reduces the effect of raindrop impact on the soil, thereby reducing erosion. Polymer

application to the soil may also retard surface sealing, reduce particle soil detachment, reduce sediment in suspension,

and compensate for low residue.

Objectives

The objectives of this study are to determine the optimum application methods and the effectiveness of the PAM-mix

under moist and dry soil conditions. The different application methods were applied to a construction site in Middleton,

WI. Data were collected to determine the most effective method of application and the effectiveness of the PAM-mix on

construction sites.

Literature Review

The use of polymers as soil conditioners has been studied for decades. The most conclusive studies, done by Lentz

et al. (1992), determined that negatively charged PAM is an excellent soil erosion deterrent for furrow irrigated fields.

It was found to be a cost-effective and safe technology. Sojka and Lentz (1994) found that PAM, when applied in

irrigation waters at rates greater than 0.7 kg/ha, reduced furrow erosion by an average of 80 to 90% and increased

infiltration on Portneuf silt loam by an average of 15%. Trout et al. (1995) reported a 30 to 110% increase in cumulative

infiltration. Roa et al. (1996) found that soils treated with PAM had infiltration volumes more than double that of untreated

soils over a two-hour period. The infiltration volumes for the untreated soils averaged 231 mV38.5 square centimeters

while those for treated soils averaged 490 mV38.5 square centimeters, or 98% of the volume of water to be infiltrated.

Roa et al. (1996) also found that the high infiltration rate of the treated sample was associated with low concentration

of sediment in the effluent or infiltrated water.

Nadler et al. (1994) found that PAM mobility in sandy loam, as well as clay loam soils, was limited to the top 25 cm

10 months after application. Clays were attached to anionic polymers more easily when salts were present in solution.

With anionic polymers, flocculation was easier and more complete. When polysaccharides are present with anionic

polymers in solution, fixation was also easier and more complete. Khamraev et al. (1983) reported that clay fixation is

best achieved for PAMs with 30% anionic charges. The cementation provided by the clay flocculation stabilizes the

aggregate at the surface. Roa et al. (1997) found that using polysaccharides, a calcium source with anionic polymers

orpolysaccharides with calcium nitrate and anionic PAM, increased the infiltration rate in saturated cores 5 times greater

than with no soil treatment.

PAM use for erosion control provides a potent environmental benefit by halting furrow erosion by about half a ton

of soil per ounce of PAM used. PAMs remove most sediment, phosphorus, and pesticides from return flows, and greatly

reduce return flow BOD (Sojka and Lentz, 1996). The consequences of reducing sediment and nutrient loading of

construction areas can ultimately be expected to reduce the frequency and intensity of algae blooms and reduce turbidity

and sedimentation of stream channels.

Lentz et al (1992) in Kimberly, Idaho, reported that when applied at 10 ppm, PAM provided a 94% reduction in runoffsediment in three years of testing. When used properly, PAM has no measurable toxicity to humans, plants, or aquatic

organisms. Molash et al. (1997) state that the Polyacrylamide Allocation Standard for Reduction of Soil Loss is

necessary because other best management practices (BMPs) are available and have varying degrees of effectiveness.

Sojka and Lentz (1996) summarized several advantages of PAMs over other erosion control BMPs: (1) PAM can

be applied using irrigation equipment and can be effective for controlling erosion over large areas, as demonstrated in

eastern Washington and Idaho; (2) PAM is very effective on fine silt/clay soils; (3) preliminary research conducted in

279
Kansas and California has indicated that PAM is effective at abating wind erosion; (4) PAM enhances precipitation of

fine silts and clay particles, providing water quantity benefits; (5) PAM increases soil infiltration capacity that reduces

runoff volumes; and (6) high benefit to cost ratio.

The types of PAM used for erosion control should have an approximate molecular weight of 12-l 5 Mg/mole, with

an 8-35% negative charge density, and contain no greater than 0.05% Acrylamide monomer (Sojka and Lentz 1996).

A recent study done by King et al. (1996) focused on comparing the uses of polyacrylamides and straw mulch on

dry bean yields. It was shown that the sediment loss was reduced for both straw mulch and the PAM treatment.

In three years of studies in construction sites using PAM for controlling soil loss, PAM has provided a 60-97%

reduction in runoff-sediment (Roa et al. 1997).

Method

Five treatments were applied to soil test plots: (1) No PAM-mix application to dry soil [control], (2) PAM-mix in

solution applied to dry soil, (3) Dry PAM-mix application to dry soil, (4) PAM-mix in solution with mulch/seeding applied

to dry soil, and (5) PAM-mix in solution applied to moist soil. Three replications of each treatment were performed using

a randomized block design on 1 m x 1 m non-vegetated plots in the Middleton Hills Development, Middleton, WI. The soil

was a Dodge silt loam. The average slope of the test site was 10%.

Plot preparations included large boulder, cobble, and excess debris removal. The surface was raked priorto testing.

Soil moisture prior to testing was about 9%.

The PAM-mix is a high molecular weight anionic granular polymer. The PAM-mix (2.25 g of PAM-mix added to 5

liters of water) was applied at a rate of 22.5 kg/ha, to the appropriate plots using a garden sprinkler. For the dry PAM-mix

application, 2.25 grams of the PAM-mix was applied using a sifter. For the PAM-mix applied to moist soil treatment, the

soil was pre-moistened by a 6.4 cm rainfall six hours before testing.

The sprinkler infiltrometer (Bubenzer and Patterson, 1982 ) was used to collect data for this study. A rainfall

simulator was used that produces 6.4 cm per hour. Actual rainfall depths were recorded using eight rain gauges for each

replication. Runoff from each plot was collected into a tank where the depth of the water was recorded at approximately

2-minute intervals during each test. The average trial time was 40-50 minutes or until the runoff collection tankwasfilled.

Runoff samples were extracted at approximately 1 O-minute intervals by diverting runoff into a collection container

during each replication to determine sediment yield. A representative sample was also taken at the end of each

replication from the tank. The samples were dried at 11 O°C for 24 hours and weighed to determine an average sediment

load for each trial.

Results and Discussion

Mean sediment yield, infiltration, and runoff depth for the three replications and the controls are presented in Tables

1,2, 3 and 4. For Replication 1, the PAM-mix solution was prepared the evening before field testing. It was noted that

the viscosity of the solution decreased throughout the day. This change may have been due to UV light, reaction with

the mix, and/or oxidative and photolytic interaction. Thereafter, the solution was prepared immediately before the rainfall

simulation. After analyzing the results, a lower viscosity of the PAM-mix solution was determined to be less effective in

controlling sediment yield. This difference is presented in Table 4. Future recommendationsforcommercial applications

may need to take into account the time of preparation of the solution and handling before application.

During the first replication of testing, the largest sediment reduction occurred when PAM-mix in solution was applied

to moist soil. The control yielded 184.4 grams per square meter and the PAM-mix in solution applied to moist soil yielded

36.4 grams per square meter resulting in a reduction of 80% in sediment yield (Table 1). The sediment yield reduction

for the dry PAM-mix application to dry soil and PAM-mix in solution with mulch/seedling applied to dry soil were

280
Table 1. Summary of rainfall, infiltration runoff, and sediment yield for Replication #l .

Treatment

Control

Dry PAM-mix/Dry Soil

Solution PAM-mix/Dry

Soil

Solution PAM-mix/Moist

Soil

Solution PAMmix/Mulch/Dry Soil

Rainfall Infiltration

(cm) (cm)

5.64 1.70

5.79 1.91

5.64 1.60

5.72 0.05

5.72 1.57

Runoff Sediment

(cm) &r-n)

4.01 184.4

3.89 68.3

4.11 103.7

5.66 36.4

4.14 67.3

Soil Loss Runoff Rainfall

% of Control % of rainfall

100% 71%

37% 67%

56% 73%

20% 99%

36% 72%

approximately 64%. The sediment yield for PAM-mix in solution applied to dry soil was reduced by 44% when compared

to the control.

In Replications #2 and #3, the lowest sediment yield occurred for the treatment of PAM-mix in solution with

mulch/seeding applied to dry soil. A sediment reduction of 97% and 89% occurred, respectively. A sediment reduction

for the treatment of PAM-mix in solution applied to dry soil was 87% and 57% respectively (Table 2 and 3).

Table 2. Summary of rainfall, infiltration runoff, and sediment yield for Replication # 2.

Treatment

Control

Dry PAM-mix/Dry Soil

Solution PAM-mix/Dry

Soil

Solution PAM-mix/Moist

Soil

Solution PAMmix/Mulch/Dry Soil

Rainfall Infiltration

W-0 b-4

4.57 0.51

5.72 1.57

4.72 0.61

4.14 0.13

4.55 0.38

Runoff Sediment

P-4 km)

4.06 377.67

4.14 178.36

4.11 48.77

4.01 242.4

4.17 12.04

Soil Loss Runoff Rainfall

% of Control % of rainfall

100% 88%

47% 73%

13% 87%

64% 97%

3% 92%

Table 3. Summary of rainfall, infiltration runoff, and sediment yield for Replication # 3.

Treatment Rainfall Infiltration Runoff Sediment Soil Loss Runoff Rainfall

(cm) (cm) (cm) (gm) % of Control % of rainfall

Control 5.05 1.12 3.94 231.34 100% 78%

Dry PAM-mix/Dry Soil 5.38 1.96 3.43 43.29 19% 64%

Solution PAM-mix/Dry 4.50 0.61 3.89 98.59 43% 86%

Soil

Solution PAM-mix/Moist 4.42 0.28 4.14 47.65 21% 94%

Soil

Solution PAM- 4.39 0.38 4.01 26.58 11% 92%

mix/Mulch/Dry Soil

When Replication #l is excluded from the results, the average sediment reduction for PAM-mix in solution with

mulch/seeding applied to dry soil increased from 87% to 94% (Table 4). The sediment reduction for PAM-mix in solution

applied to dry soil was 76%. For dry PAM-mix applied to dry soil, the sediment reduction was 17%, and the sediment

reduction of PAM-mix in solution applied to moist soil was 77%.

Conclusion

Our results show that, regardless of the application method, PAM-mix was effective in reducing sediment yield in

the test plots. The most effective method of soil treatment throughout this study in reducing sediment yield is PAM-mix

in solution with mulch/seeding applied to dry soil. The ease of application, low maintenance, and relatively low cost

281
associated with PAM-mix makes it a practical solution to costly existing methods being implemented. The evidence from

the field application in this study reflects that PAM-mix is a tool to reduce soil loss on bare soil until vegetation cover is

established.

Table 4. Average summary of rainfall, infiltration runoff, and sediment yield for Replications 1, 2, and 3 and Replications 2 and 3, excluding

Replication 1.

Treatment Runoff

(cm)

Control

Dry PAM-mix/Dry Soil

Solution PAM-mix/Dry Soil

Solution PAM-mix/Moist Soil

Solution PAMmix/Mulch/Dry Soil

4.01

3.81

4.04

4.60

4.11

Sediment

(gm)

264.51

96.65

83.71

108.82

35.32

Soil Loss % Sediment (Gm) Soil Loss % % of Rainfall

Replication Excluding Replication 2 And 3

1, 2, and 3 Replication 1

100% 304.51 100% 79%

37% 110.83 36% 66%

32% 73.68 24% 81%

41% 145.03 48% 97%

13% 19.31 6% 84%

The primary factor that must be considered in future studies is the time of polymer solution preparation and

application. It was noted that the optimal application procedure is to prepare the solution immediately prior to application.

This procedure is necessary in order to limit the amount of degradation and maximize the performance of the PAM-mix.

References

Bubenzer, G.D., and Patterson, A.E., Intake Rate: Sprinkler Infiltrometer, Method of Soil Analysis, Part 1, Physical and

Mineralogical Method, Second Edition, Chapter 33, pp. 845870. (Agronomy Monograph Series #9, 1982)

Khamraev, S.S., Artykbaeva, K., Nizamova, F. and Akhmedova, V. (1983): Leaching of salts from takyr soils conditioned

by amide-containing polyelectrolytes. Uzb. Khim. Zh. 4,16-20 (Russian). Chem. Abst. 99, 138730 (1983)

King, B.A., B. Izadi, MS. Ashraf, R.H. Brooks, and W.H. Neibling. 1996. On-farm comparison of polyacrylamide and

straw mulch on dry bean yields, irrigation performance and erosion. University of Idaho Publication No. 101-96, pp.5559

Lentz, RD., I. Shainberg, R.E. Sojka, D.L. Carter 1992. Preventing irrigation furrow erosion with small applications of

polymers. Soil Sci. Sot. Am. J. 56:1926-1932.

Lentz, R.D and. Sojka, R.E. 1996. Five year Research Summary Using PAM in Furrow Irrigation. University of Idaho

Publication No. 101-96, pp. 1 l-20.

Nadler, A.,M. Magaritz, and L. Leib. 1994. PAM application techniquesand mobility in soil. Soil Science 158(4): 249-254.

Roa, A., 1996. Screening of Polymers to Determine Their Potential Use in Erosion Control on Construction Sites,

University of Idaho Publication No. 101-96, pp.77-83.

Roa, A., Bubenzer, G.D, and Miyashita, E., 1997. Determination of PAM Use Potential in Erosion Control. Proceedings

of the first European Conference of Water and the Environment. Innovation Issues in Irrigation and Drainage. Edited by

Pereira et al. Institute of Agronomy, Technical University of Lisbon, Portugal.

Molash, E. 1997. WSDOT Stormwater Management Plan Page 148 V 5.3 3.25148

Trout. T.J., Sojka, R E. and R.D. Lentz. 1995. Polyacrilamide effect on furrow erosion and infiltration. Trans. ASAE. 38(3):

761-765.

Sojka, R. E. and Lentz, R.D., 1994. Polyacrylamide (PAM): A New Weapon in the Fight against Irrigation Induced

Erosion, USDA-ARS Soil and Water Management Research Unit Station Note #Ol-94.

282
Sojka, R.E. and Lentz, R.D., 1996. A PAM Primer: A Brief History of PAM and PAM-Related Issues, University of Idaho

Publication No. 101-96, pp. 1 I-20.

Stephens, S.H., Final Report on the Safety Assessment of polyacrylamides, J. Am. COIL Toxicol., 10:193-202.

Wisconsin Department of Natural Resources (WDNR), 1994. The Wisconsin Quality Assessment Report to Congress,

PUBL-WR 254-94-REV, Wisconsin Department of Natural Resources, Madison, WI.

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Construction Site Planning and Management Tools

for Water Quality Protection

Thomas Mumley

California Regional Water Quality Control Board

San Francisco Bay Region, Oakland, California

California is seemingly a developer’s paradise. Population is on the rise, the economy is good, and there is little

or no rain to interfere with construction for nearly eight months of the year. To top off these benefits, the California

Regional Water Quality Control Board, San Francisco Bay Region (Regional Board) has a comprehensive Construction

Site Planning and Management Program (Program). It is based on the integration of a strong regulatory and

enforcement posture, an outreach and education strategy, and technical assistance. The keys to the success of the

program are the balance of actions among these elements and implementation tools for actions within them.

Background

The Regional Board is the state agency in California responsible for protection of water quality and enforcement

of water pollution control regulations, including National Pollutant Discharge Elimination System (NPDES) permits. The

California Water Code provides the Regional Board with strong enforcement authority. This authority ranges from a

notice to comply, to a notice of violation, to enforcement orders, to monetary penalties. Penalties can be as high as

$10,000 per day of violation or $10 for each gallon of waste discharged. The Regional Board may also suspend part

of a penalty in exchange for an environmentally beneficial project.

In the San Francisco Bay Region, the Regional Board is responsible for enforcement of a general NPDES permit

for stormwater discharges from construction sites of five acres or greater. The general permit requires implementation

of an effective Stormwater Pollution Prevention Plan (SWPPP) that includes best management practices (BMPs) for

erosion and sediment prevention and control and management of equipment, materials, and wastes. The Regional

Board is also responsible for enforcement of NPDES permits for municipal stormwater discharges that have been issued

to all municipalities (regardless of population) in the urban areas of the region. These permits include requirements to

control discharges from construction sites (regardless of size). There is an inherent overlap of Regional Board and

municipality authority over construction of five acres or greater. The Regional Board’s Program recognizes and takes

advantage of this overlap of authority.

Inspections

The Regional Board initiated an aggressive construction site inspection and enforcement effort in 1997. This

resulted in discovery of significant water quality problems associated with sediment discharges caused by minimal or

token erosion and sedimentation control actions. Some of the most common observations were:

l No permit.

l SWPPP not developed, not implemented, or deficient, especially in terms of timing.

l Mass grading allowed to continue throughout winter months until rain and muddy conditions make further work

impossible.

l Mass grading continues past the time when grasses will grow and germinate; first rains simply carry seed/mulch

away with eroded soil.

9 No erosion control measures; reliance solely on sediment basins.

l Sediment basins are frequently undersized, improperly designed, and not maintained.

284
l Site not monitored to assess BMP effectiveness.

l SWPPP not updated to reflect changes in site conditions.

l Hillsides stabilized with hydroseed, but no mulch (resulting in rains carrying seed material away with eroded

soils).

l Control measures driven by “tokenism” with control measures intended to demonstrate good intentions rather

than real effectiveness.

l Willingness to risk fines in order to maximize work during winter (rainy season) months.

l Local agencies, specifically planners and engineers with plan-approval authority, often unaware of “best”

management practices.

l Sites approved by local authorities for mass grading during rainy season.

. Local authorities review and approve erosion control plans but do not inspect sites.

Enforcement Actions

Several types of enforcement actions evolved from these findings. The first consisted of the development and

issuance of a “Notice to Comply” (Figure 1). Often (25 - 35 % of the time) operators at a site are unaware of their

requirements or appropriate BMPs. The Notice to Comply is essentially a “fix-it” ticket that results in no further

enforcement action if corrective action is implemented. Regional Board inspectors are authorized to issue Notices to

Comply in the field, and use of this simple enforcement tool has proven to be an effective mechanism to gain timely

corrective action at construction sites.

Other enforcement tools are used in circumstances where the severity of the problem warrants more intensive

enforcement action. These include, in terms of progressive severity: a Notice of Violation, a Cleanup and Abatement

Order, and a Cease and Desist Order. Violations of any of these actions typically lead to more aggressive enforcement

action. The most aggressive enforcement action is imposition of administrative civil liability (monetary penalties).

During the 1997/98 rainy season the Regional Board imposed over $1 million in penalties, ranging from $10,000

to $230,000. A major consideration in determining penalty amounts is ensuring that it does not pay to pollute. Due to

the economic and time pressures associated with many development projects, minor penalties may simply constitute

a cost of doing business. The Regional Board has clearly stated its intolerance to this circumstance and intends to

severely penalize repeat offenders. Clearly, such penalties not only get the attention of the violator, but the building

industry as a whole. Substantive penalties have also provided opportunities to fund environmental education projects

in lieu of direct payment of penalties. The Regional Board has favorably accepted development of technical assistance

tools as appropriate mitigation projects.

Education and Outreach

The Regional Board recognizes that regulation without education is ineffective. Consequently, its program includes

extensive outreach efforts. These include:

l Mass mailing to construction projects of more than five acres and projects permitted for winter grading

summarizing requirements and findings on inadequate performance

l Meeting with development community and local agencies prior to the rainy season (August through September)

to better communicate concerns and requirements and to establish a dialogue

l Providing detailed guidance and training for both developers and municipalities on their responsibilities and on

effective control approaches

285
San Francisco Bay Regional Water Quality Control Board

1515 Clay Street, Suite 1400, Oakland, CA 94612 /Phone (510) 622-2300 - FAX (510) 622-2460

NOTICE TO COMPLY

You are hereby notified that

Order No.

q NPDES Permit No. (if applicable)

q California Water Code Section

•I Other

Federal, State, and Local Agency Contacts:

(hereafter Discharger) has violated provisions of: 0

I. FACILITY INFORMATION

Inspection Date: Time:

Discharger Contact:

Site Name & Location:

Headquarters/Owner Name & Address :

Title:-

Prior Notification: q Yes q No q Unknown

Phone: (-)

County:

II. NON-COMPLIANCE INFORMATION

Nature of Violation : Recommendation to Correct : Time to Comply (Not to exceed

30 days)

III. SIGNATURE SECTION

I acknowledge receipt of this Notice (must be owner, operator, or duly designated representative of facility):

RECIPIENT NAME (print): TITLE:

SIGNATURE: DATE:

STAFF NAME: PHONE:(-)

SIGNATURE: DATE:

IV. CERTIFICATION OF COMPLIANCE

Sign and return by mail or fax within 5 working days of achieving compliance

I certify under penalty of perjury that the above violation(s) have been

corrected.

I am aware that there are significant penalties for submitting false information.

Recipient Signature:

Print Name:

Date:

Title:

FOR REG. BD. USE ONLY

Receipt Date: Acceptable:

I I q No

Reviewed by: 0 Yes

Recommendation:

Date:

Figure 1. Notice to Comply

The objectives of these outreach efforts are:

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l Commitment from the construction industry to include erosion control in their planning, scheduling, and (most

importantly) project implementation

l Commitment from municipalities to play a greater role in SWPPP review and implementation, including training

inspectors so that builders, municipal staff, and Regional Board staff are all on the same page - thereby allowing

for consistent regulation of construction activities by applying a uniform standard.

In response, the building industry and municipalities have collaborated with the Regional Board on the production

of training workshops on construction site planning and management for both building industry and municipal staffs.

The workshops provide a review of regulations and responsibilities including:

l State responsibilities

. Permits for work in or near streams

l Local agency responsibilities

l Plan approval authority and requirements

l On-Site responsibilities (plans, permits,inspections)

l Inspector responsibilities

l Enforcement

l Field inspection coordination (i.e., state agency/municipality)

The workshops also include training on BMPs for erosion and sediment control (principles, tools, corrective

measures, inspections, monitoring, reporting), non-stormwater discharge prevention and management, and a field trip

to an active construction site where vendors demonstrate both proper and improper installation practices.

Production of the workshops has been funded in part through mitigations associated with administrative civil liability

fines. Similarly, penalty mitigation funds have been used to develop education tools including:

l An 18 minute training video entitled “Hold on to Your Dirt: Preventing Erosion from Construction Projects” which

provides information on BMPs for grading projects and for stabilizing disturbed land

l An 18 minute training video entitled “Keep it Clean: Preventing Pollution from Construction Projects,” which

provides information on BMPs to prevent water pollution from non-stormwater discharges from activities such as

painting, stucco, concrete washout facilities and saw cutting

l A booklet of “Guidelines for Preparing a Storm Water Pollution Prevention Plan”

Erosion and Sediment Control Field Manual

The centerpiece of the Regional Board’s Program is an Erosion and Sediment Confrol field Manual (also

developed with penalty mitigation funds). The FieldManualwas produced in response to a common complaint by “field”

personnel that there is a need for information on cost-effective and proven BMPs, and that existing references were too

technical and difficult to read. The FieldManualcontains concise descriptions of BMPsfor erosion and sediment control

and site management (Table 1). Overviews of regulatory requirements and inspection and monitoring responsibilities

are also provided.

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Table 1. Erosion and Sediment Control Field Manual BMPs

Erosion and Sediment Control Field Manual BMPs

Erosion and Sediment Control Practices

l Scheduling

l Preservation of Existing Vegetation

l Slope Grading

l Temporary Seeding and Mulching

l Permanent Seeding and Mulching

l Hydromulching - Hydroseeding

l Dust Control

l Erosion Control Blankets and Geotextiles

l Fiber Rolls

l Temporary Stream Crossing

l Stabilized Construction Entrance

l Entrance/Exit Tire Wash

l Outlet Protection - Energy Dissipation

9 Check Dams

l Silt Fencing

l Temporary Straw Bale Dike

l Sand/Gravel Bag Barrier or Rock Filter

l Storm Drain Inlet Protection

l Catch Basin Inlet Filters

l Sediment Basin

l Sediment Traps

l Dewatering: sediments/toxic pollutants

l Secondary Filtration

General Site and Materials Management Practices

l Water Conservation Practices

l Solid and Demolition Waste Management

l Hazardous Waste Management

l Spill Prevention and Control

l Vehicle and Equipment Service

l Material Delivery, Handling, and Storage

l Paints and Liquid Materials

l Handling and Disposal of Concrete and Cement

l Pavement Construction Management

l Contaminated Soil and Water Management

l Sanitary/Septic Waste Management

l Landscaping Management

BMPs are described in a user-friendly format that features full-color graphics, including do and don’t illustrations

(Figure 2). Each BMP description includes its purpose, application, limitations, practices, inspection, and maintenance.

There is a section on Corrective Measures that discusses what can go wrong and common installation problems. This

latter section is essentially a troubleshooting guide that contains a table of common problems and corresponding

corrective measures. Overviews of regulatory requirements and inspection and monitoring responsibilities are also

provided. The Field Manuals waterproof 9” x 9” binder and coated pages make it ideal for use in the field. As such, it

provides the essential connection between the enforcement, outreach, and technical assistance components of the

Regional Board’s Program.

Overlap of State and Municipal Authorities

The Regional Board’s Program provides a clear demonstration of how the Storm Water Phase II Program’s

construction requirements may be implemented. The Phase II rule allows states to recognize compliance with municipal

program construction requirements as equivalent to compliance with a state-issued NPDES permit for construction,

if it can be demonstrated that the municipal program requirements are equivalent. In such situations, a construction site

deemed in compliance with a municipality’s requirements would be deemed in compliance with the state-issued NPDES

permit. The key is demonstration that the municipal program qualifies as equivalent.

In the San Francisco Bay area, as previously noted, the Regional Board has issued NPDES permits for municipal

stormwater discharges that include requirements to control discharges from construction sites. In essence, there is an

overlap of Regional Board and municipal authority where municipalities are in compliance with their permit requirements.
SHORT CIRCUIT

BAFFLES WILL INCREASE DETENTION TIME

Figure 2. Sediment Basin Design.

Unfortunately, what may seem equivalent on paper may not be equivalent in practice. The case in point is that the

Regional Board’s inspection program noted above identified many construction sites out of compliance with their

construction NPDES permits. Consequently, these same construction sites would be deemed in non-compliance with

municipal requirements, In addition, the same inspection findings can be applied to the municipality. Since the

municipality’s NPDES permit requires it to control discharges from construction sites, construction site non-compliance

means the municipality is not in compliance with its NPDES permit. In these circumstances, the Regional Board may

(and has) taken enforcement action against both the construction site and the municipality.

To date, the primary enforcement tool used for the municipalities has been Notice to Comply. The Notice to Comply

requires the municipality to report on the failure of its construction control program and to implement timely corrective

actions. Most municipalities have been very responsive to this “wake-up-call,” and have made improvements to

demonstrate the desired “equivalency.” The net result is a negative turning into a positive. The Regional Board’s

Program, with its balance between enforcement and education, has provided a de facto mechanism for recognizing

municipal program equivalency allowed by the Phase II rule. By its design and implementation, the program essentially

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requires municipalities to demonstrate such equivalency. Consequently, the Regional Board will significantly reduce or

eliminate its inspections in municipalities where Regional Board inspections find construction sites in compliance, thus

providing incentive and reward to both the building industry and municipalities.

Lessons Learned

Lessons learned in the development and implementation of the Regional Board’s Program are summarized in the

following points:

. The only effective means of controlling erosion is erosion prevention, which requires careful planning and

adherence to seasonal time-lines. Sediment capture should be used only as a secondary or back-up plan.

. Regulation without education is ineffective. Often, noncompliance is due to lack of awareness of the regulatory

requirements and cost-effective, proven BMPs.

l Education without enforcement is impotent. Despite good intentions, the building industry is constantly trying to

maximize its investment dollars, and environmentally sound BMPs are often superseded by time pressures to

complete a project.

l Enforcement actions must be severe enough that they cannot be accepted as a cost of doing business.

l The balance between regulation and education is dependent on readily available technical assistance and

implementation tools.

l Outreach and technical assistance needs to be directed to the right audiences. Workshop agendas and

attendance were initially misdirected toward planners and local decision makers. Key attendees are municipal staff

who actually review SWPPP plans and perform on-site inspections and building industry staff who are onsite.

Evaluations revealed attendees wanted more technical information on installation and less time spent on municipal

general plan/environmental plug. Audiences are especially responsive to builders discussing their experiences

in implementing BMPs.

l Both the building industry and municipalities have historically short shrifted training. Workshop attendees

expressed relief that practicable training is finally available - especially information on vendors, cost comparisons,

and practical BMPs. The building industry and municipalities now realize costs of training are minimal relative to

the benefit.

Conclusions

The bottom line is that environmental regulators, municipalities, and the building industry have different priorities that

must be reconciled. Regulators seek no adverse impacts to waters. Municipalities seek economic growth. Builders want

unfettered development. In the case of construction-related erosion, the means to each end is the same...effective

erosion and sediment control. A little more work on the part of each party involved has proven that their different

priorities are attainable and even harmonious.

Since the Regional Board made enforcement a top priority and began a collaborative effort with the building industry

and municipalities to provide cost-effective outreach and training, construction site compliance with NPDES permit

requirements has risen from 20% three years ago to greater than 90% today. Municipal compliance has risen similarly.

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Regulating Sedimentation and Erosion Control into Streams:

What Really Works and Why

Seth FL Reice

Department of Biology

University of North Carolina at Chapel Hill

Chapel Hill, NC 27599-3280 (address all correspondence to this author)

JoAnn Carmin

Department of Public Policy

Virginia Polytechnic Institute and State University

Blacksburg, VA

Abstract

The overall objective of this project was to determine the effectiveness of different environmental policies,

regulations, and incentives in reducing the ecological risks and consequences of sedimentation to streams. We were

trying to learn which sets of regulations, enforcement strategies, and landscapes result in effective protection of stream

communities from degradation, resulting from erosion and sedimentation from construction sites. By connecting erosion

control efforts to environmental impacts, our aim was to create more effective management strategies that ultimately

provide environmentally sustainable social and economic development in our watersheds.

We chose four replicate construction sites in each of three regulatory jurisdictions that varied in stringency of

regulations and enforcement activities. At each site, we conducted instream assessments of water quality and

biomonitoring of macroinvettebrates and fishes to determine the success of the regulators in protecting stream

ecosystem health. We combined these results with evaluations of the regulatory environment to link the policies and

management styles of the regulators to the effectiveness of protection of the streams. While all construction sites did

some damage to the steams, we found that enforcement style and frequency of inspections were far more important than

the nature of the regulations in preventing sediment pollution of streams.

Keywords: Development, enforcement, rivers, sedimentation, streams, regulations, regulatory effectiveness.

Introduction

A critical problem in American rivers and streams is sedimentation. Sedimentation degrades water quality, alters habitat

for fish and macroinvettebrates, limits ecosystem functions and services, and reduces the aesthetic and economic value

of rivers and streams. Many regulations and policy incentives have been devised to control sediment pollution of our

rivers and streams. Yet there has rarely been an attempt to reconnect the policies with the ecology of the rivers. That

was the goal of this research. This work integrates the regulatory environment, sediment ordinances, and policies with

resultant ecological impacts of sedimentation on rivers and streams. The question the ressearch sought to answer was

“What combinations of policies, regulations and on-site interactions between regulators and developers really work to

enhance stream biota and stream ecosystem health?”

Research goals were accomplished by comparing similar streams in different regulatory jurisdictions (a comparative

watershed approach). We tested the effectiveness of different intensities of sediment control regulations and

enforcement. We used the streams to tell us what matters ecologically. The selected political jurisdictions differed in

the stringency of their erosion and sediment control requirements and the nature and intensity of enforcement of the

regulations. We chose 17 construction sites along streams in three different jurisdictions. We interviewed the regulators

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and developers at each site and we studied the regulations and the attitudes of the regulators and developers. At each

site, we sampled the streams being impacted. Some projects are still unfinished. Therefore, we will present only the

results of the ‘before construction’ and ‘during construction’ samplings.

We asked “Which erosion and sediment control regulations really work and why?” We have analyzed the erosion

and sedimentation control regulations and compared them among the respective jurisdictions. Then we surveyed the

attitudes and enforcement activities at all levels within each jurisdiction. This paper will briefly outline our findings and

focus on what can be done to minimize sedimentation into streams from construction sites.

Methods

Site Selection

We selected three regulatory jurisdictions so they would vary across a range of two critical variables: (1) stringency

of regulations (how strict and how rigorous the rules are) and (2) stringency of enforcement (i.e. frequency of inspections,

severity of punishment of violations). A summary of some of the salient characteristics of the three regulatory jurisdictions

is given in Table 1. Construction sites were selected from the array of applications for grading permits filed with the

erosion and sediment control offices in each jurisdiction. The biggest constraint in locating study sites was the availability

of construction sites on streams with riffle zones, One jurisdiction (District IV) extends eastward into the coastal plain

as does Eastern Wake County. Therefore, many otherwise promising sites, which had sandy bottomed, slow flowing

streams, were eliminated from our study. To be selected for this study, the construction sites had to have certain critical

characteristics. For example, streams had to be within 100m of the site. There also had be a significant slope from the

construction site down to the stream, so that if erosion occurred it would impact the stream. These factors made site

selection extremely difficult. In this paper, we will discuss only the impact of large construction sites (>lOO acres

disturbed). We have located and sampled ten large sites.

Table 1. Selected Characteristics of Erosion and Sediment Control Jurisdictions Used for this Project

Minimum Disturbed

Area Requiring

Erosion Plan Staff

Orange County

# Field Total Area # Active Site/Staff

(Miles’) Projects Ratio

0.5 Acres 3 400 -100 33.3

Wake County 1 .O Acres 4 858 -400 100

District 4’

(16 Counties)

1 .O Acres 4 8,116 -1000 250

’ District 4, of the NC Division of Land Quality oversees all construction projects in all 16 counties without a Local Erosion and Sediment Control

Program. It covers all governmental construction in the District 4 area, including Orange and Wake Counties. So, a single stream can have adjacent

construction sites along the banks, one supervised by District 4 and the other by the Local Program.

Stream Sampling Procedures and Variables Sampled

We monitored at least three replicate sites per jurisdiction for the large construction sites. We sampled before,

during, and after construction. We cannot control the timing of the construction projects, and since sampling must follow

a rain of >1/2” in 24 hours (i.e., a rain with the potential to produce erosion and sedimentation), our sampling was

dependent on the weather and the contractors. This means that the time between the before, during, and after sampling

is highly variable. Since upstream and downstream controls were sampled on the same day as the “at the site” samples,

this did not cause a significant analytical problem.

We sampled three sites on each stream, including >l OOm upstream, at the site, and ~1 OOm downstream. We took

two replicate Surber samples for macrobenthos, identified to species whenever keys permitted, including chironomids.

Chironomids are essential because they often constitute >90% of the individuals sampled, especially in the impacted

reaches. The number of samples is small since our objective was not to analyze any one stream in detail, but to treat

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streams as replicates. In the overall analyses, multiple samples per site are pseudoreplicates. The mean of the replicate

Surber samples was used in the analyses. We electroshocked for fish along one 50m reach of riffles and pools. We

collected basic water chemistry data. Water quality parameters included D.O., turbidity, conductivity, Total N, NH,+, NO,

‘, Total PO,-‘, SRP, pH, and temperature. We also studied leaf litter decomposition rates. Five g leafpacks of Cornus

florida (dogwood) leaves were incubated for two weeks in situ at all three sites in the “during construction” period to

assess the critical ecosystem process of litter decomposition.

Environmental Policy Analysis

Surveys and semi-structured interviews were used to investigate both the regulatory agencies and developers. The

surveys focused on the capacityof the agency, the external commitmentthat the agency receives, as well as the internal

commitment toward the environment, and the control measures that are used. The surveys and interviews achieved

a 100% response and participation rate. Although it has been harder to get their cooperation, we have nearly completed

data collection from developers. The survey data is being augmented with documentary data from the sediment and

erosion control offices in each of the counties.

The evaluation of implementation focused on (1) the extent to which developers comply with sediment and erosion

control regulations and (2) the way that regulatory and organizational factors interact to shape compliance behaviors.

The examination of outcomes combines social science and biological data to examine associations among regulatory

styles, agency activities, and stringency of policy enforcement. We further analyzed how variations in sediment and

erosion control enforcement are related to the ecological outcomes (including biological, chemical, and physical factors)

in the impacted streams.

Hypotheses

Hypothesis 1. Greatest degradation will be evidenced at the construction sites, compared to upstream controls, with

moderate to complete recovery downstream.

Hypothesis 2. Tighter enforcement of erosion and sediment control laws will result in less damage to streams.

Hypothesis 3. Stronger erosion and sediment control regulations will result in less damage to streams.

Results

Nearly all biotic and environmental variables measured tell the same story. Figure 1 shows the changes in the EPT

Index for the during construction sampling. That is the species richness of the Ephemeroptera (the mayflies), Plecoptera

(the stoneflies), and Trichoptera (the caddisflies). The tally of EPT taxa (i.e., EPT Richness or the EPT Index) is a wellestablished and universally accepted measure of stream health. These groups of aquatic insects are particularly

sensitive to (and highly intolerant of) high temperature, low oxygen, toxic substances, a wide range of pollutants, and

burial by sedimentation. An abundance of EPT species and individuals and high EPT diversity are clear indicators of

good stream health. Reductions in EPT values demonstrate degradation of stream conditions.

EPT richness follows a pattern. The differences between jurisdictions are clear. The greatest decline in EPTvalues

from upstream to at-the-site occurs in District IV. The EPT Index in Orange County changes little at any site. Wake

County actually shows some enhancement of the EPT richness as you go from upstream to at-the-site. We sampled

many other variables but the results parallel the EPT richness.

A short summary of the enforcement activities and attitudes of the regulators in the various jurisdictions is found in

Table 2. These data show that these agencies differ in these aspects. Orange County had the strictest enforcement,

penalizing nearly 25% of all construction projects, while Wake penalized -22% and District IV penalized only - 4.5% of

the projects they inspected. Orange County is most likely to use stop-work orders to halt construction due to

sedimentation violations, while District IV relies on fines. District IV is perceived as being so understaffed that it is unable

to make sufficient inspections. Consequently, some contractors do not feel obliged to follow their approved plans. Some

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contractors agree to a plan and then cut costs by not following the sediment controls. This laxity is detectable from the

stream data (see Figure 1).

Total EPT Richness

:

District IV Orange

Upstream

Figure 1. Total EPT Richness.

Table 2. Regulatory Environment

Agency/Variables

Wake

I

Distnct IV Orange Wake

At The Site

Error bars = 1 std. error

Disfrict IV Orange Wake

Downstream

Orange County NC District IV Wake County

Enforcement Action

Penalties enacted past year

Stringency of Penalties

Very Strict

24

High

Average

44

Medium

Strict

88

Medium

Attitudes uf Regulators

Perception of official commitment Supportive

Percent of developers that regulators 8

Very Supportive

40

Indifferent

10

Orange County and Wake County regulators generally think that developers will try to avoid complying with erosion

and sediment control regulations. As the regulators’ workload increases, their task becomes more difficult. This may

result in regulators adopting a more forgiving attitude toward developers and less vigorous enforcement of the

regulations. District IV regulators think that fully 40% of developers are trying to comply with the regulations.

Discussion

There is a clear link between the attitudes and enforcement activities of the regulators of erosion and sediment

control ordinances and environmental outcomes in the streams near construction sites. If the regulations are completely

effective, all sites should be similar to the upstream controls when the construction is completed and the site has been

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stabilized (i.e., revegetated). In our analysis, the degradation is clearly detectable in the benthic community data (see

Figure 1). Benthic communities at the site are dramatically negatively impacted in District IV, unchanged in Orange

County, and actually enhanced in Wake County. The effect is sometimes reduced downstream but the degradation

persists downstream in District IV.

Wake County and District IV have identical regulations, while Orange County’s regulations are more stringent.

Comparison between the two jurisdictions with the same rules but different inspection and enforcement intensities will

help us tease apart these factors. The stream data suggest that the laws, as written, are not particularly important. Wake

County has the best environmental results while District IV has the worst stream degradation. Our analysis suggests that

differences in laws and regulations have limited impact on the degree of degradation of stream biota.

The key factors seem to be the attitudes and enforcement behavior of the regulatory agencies. The frequency of

on-site inspections is particularly important. In Orange County, every construction site is inspected every week. If it is

a problem site, the inspectors may visit daily. In Wake County, the inspections are closer to every other week. In District

IV, the goal is to visit every site once in the entire duration of the project. They also seek to respond to any citizen

complaints within one week. In Orange County a complaint generates an inspection within one day. Another critical

factor is topography. A very steep, erodible slope can undermine the best attempts at enforcement of erosion and

sediment control regulations.

Our analysis suggests that differences in the nature and frequency of enforcement and inspections does matter.

Developers tell us that a rigid, command and control approach to enforcement is less palatable to them than a flexible

problem-solving cooperative approach. If the developers perceive that the regulators are really tying to help them keep

sediment on site and out of the streams, they do a better job. Flexibility enters in as follows. If the sedimentation

inspectors have enough time to analyze a sedimentation problem in detail, their suggestions will be better. Very often,

the inspectors need the authority to implement solutions which are not exactly “by the book.” When inspectors propose

innovative solutions, which can really solve the problem, this encourages the developers to be more cooperative. More

frequent inspections and a cooperative, flexible approach by regulators does ameliorate the stream damage among

similar streams in different jurisdictions.

On the other hand, if the developers know that the regulators will in fact shut them down (with a stop-work order or

a court injunction), it is easier for the regulators to get developers’ attention. Fines are notoriously ineffective penalties

in North Carolina. Presently the maximum fine is $500 per day. When developers are pouring millions of dollars into

a project, this amount of fine is trivial. As one said, “It’s just a cost of doing business.” In essence, the effectiveness of

erosion and sediment control depends more on enforcement than on how the regulations are written. Even with weak

laws, the success of Wake County’s Erosion and Sedimentation Control Program plainly depends on their on-site

enforcement actions.

Recommendations

. Provide sufficient inspectors to visit each construction site at least weekly.

l Give inspectors the authority and knowledge to implement innovative solutions to erosion problems on a sitespecific basis.

l Empower the inspectors to issue severe penalties (stop-work orders) in the case of sedimentation violations.

l Raise the maximum level of fines to a meaningful amount (we suggest $10,000 per day).

l Educate the development community to the damage that sedimentation does to stream communities.

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Effectiveness in Erosion and Sediment Control:

New Initiatives in Indianapolis

James Hayes

Marcia Mathieu

Marion County Soil and Water Conservation District

Indianapolis, Indiana 46237

marcia-matthieu Q iaswcd.org

Greg Lindsey

Center for Urban Policy and the Environment

School of Public and Environmental Affairs, Indiana University

Indianapolis, Indiana 46204

glindsey@iupui.edu

Since the late 196Os, when the severity of pollution from sediment from construction sites was first documented,

many states and municipalities have worked to develop effective programs for erosion and sediment control. These state

and local programs were augmented in 1987, when Congress required in the Clean Water Act that operators of all

construction sites over five acres prepare erosion and sediment control plans and obtain National Pollution Discharge

Elimination Permits (NPDES). At that time, some states, such as Maryland and North Carolina, already had wellsupported, comprehensive approaches that were developed largely in response to state law. Other states, including

Indiana, have relatively new programs that were adopted only after the federal mandate. In general, these newer

programs are not as comprehensive, and managers are still working to develop systematic and effective methods for

implementation.

This paper describes a new initiative in Indianapolis, Indiana, to increase the effectiveness of erosion and sediment

control programs. The paper describes a general framework for evaluating erosion and sediment control programs.

Next, it describes an intergovernmental, “S.W.A.T.” team approach to inspection that was used in Indianapolis in the

summer of 1998. The paper summarizes the results of the inspections and concludes with a discussion of the

implications for managers of erosion and sediment control programs.

Effectiveness in Erosion and Sediment Control Programs

Managers and analysts in Maryland and North Carolina have used a general framework for evaluating erosion and

sediment control programs (Clevenger, nd.; Departments of Civil Engineering and City and Regional Planning, 1990).

The framework comprises five criteria, each of which must be satisfied for sediment pollution to be controlled effectively:

l Complete coverage

l Competent plans

0 Careful installation

l Continual maintenance

l Consistent enforcement

Overall effectiveness requires that the coverage rate (the proportion of construction sites with controls) approach 100%.

Operators of development sites must know of regulatory requirements and make efforts to comply. Second, erosion and

sediment control plans must be competent. Best management practices (BMPs) incorporated into plans by engineers or

technicians must be able, if constructed properly, to control erosion and sedimentation. Third, BMPs must be installed

completely and correctly. Improper installation may result in failure and off-site sedimentation. Fourth, BMPs must be
maintained for the duration of the construction process. Finally, consistently effective approaches to enforcement must be

developed to ensure compliance with substantive criteria. If any one of these criteria is not met, the objectives of erosion and

sediment control may not be achieved.

When new programs are developed, these criteria can be considered sequentially. That is, when building a new program,

managers must first make sure that developers and builders are aware of regulatory requirements. Next, they must work to

ensure that developer’s engineers are preparing good plans. If developers are aware of requirements and are submitting good

plans, attention can turn to installation and maintenance. Use of enforcement tools always is a last resort.

An Initiative in Indianapolis

Although the City of Indianapolis has a sediment control ordinance that predates federal requirements, erosion and

sediment control programs in Indiana have largely been developed in response to a state regulation [Title 327-IAC 15-5

(Rule 5)], that was adopted in 1992 to comply with EPA regulations. Since the adoption of Rule 5, managers generally

have seen improvements in efforts to comply. Most developers and builders are now aware of requirements, and

coverage is approaching 100%. With respect to plan review, the Division of Permits in the Department of Capital Asset

Management (DCAM) is responsible for plan review pursuant to the city’s ordinance, while, under a memorandum of

understanding with the Indiana Department of Environmental Management (IDEM) and the Department of Natural

Resources (IDNR), the Marion County Soil and Water Conservation District (District) is responsible for plan review

pursuant to Rule 5. MCSWCD reviewers estimate that the quality of plans is improving, but that as many as 60 to 70%

of all plans still must be returned and revised before approval. Most plans are approved on the second iteration.

Although the review process now assures that competent plans are being prepared, installation often remains

inadequate, BMPs often are not maintained, and resources for inspection and enforcement are limited. IDNR has only

seven inspectors in the Division of Soil Conservation for all 92 counties and 550 municipalities. IDNR inspectors

generally work individually within regions, inspecting sites sequentially and in response to complaints. District personnel

lack enforcement authority and mainly visit sites in response to complaints. In Indianapolis, sediment control has been

a low priority with DCAM, which has no inspectors trained in or assigned exclusively to enforcement of sediment control

requirements.

Managers have struggled to find ways to overcome resource limitations and to increase the effectiveness of

implementation. In 1998, IDNR and District staff conceived of a “S.W.A.T.” team approach to inspection. In this

approach, all IDNR inspectors and District staff together focused their efforts on all open construction sites in the county.

The objective was to visit all sites in a brief time period, thereby increasing the visibility of the program. Managers

believed that intensive scrutiny of the county, if only for a brief time, would result in greater efforts at compliance. One

of the assumptions on which this approach was based was that there are both formal and informal networks among

developers and builders and that this approach would stimulate discussion about compliance issues.

In Indianapolis, IDNR and District personnel completed a county-wide survey of construction sites on June 23 and

24,1998 (Hayes and Matthieu 1998). DCAM staff was invited to participate. IDNR, District, and DCAM staff visited more

than 300 construction sites. Of these sites, 177 were active and were evaluated for compliance with Rule 5.

Construction had not yet begun at 23 of the sites, construction had been completed at 61 sites, and the remainder were

not evaluated because they were inaccessible or because construction was just beginning. This summary is restricted

to the sites under active construction. The results provide a good picture of the current status of implementation and the

general level of effectiveness of erosion and sediment control requirements in Indianapolis.

Inspectors evaluated sites for compliance in nine categories using a standardized checklist developed by IDNR.

Sites also were checked for obvious evidence of off-site sedimentation. The nine categories were: (1) proper installation

of erosion and sediment control measures; (2) perimeter erosion control measures; (3) erosion and sediment control

measures on individual building sites; (4) protection of storm-sewer inlets; (5) stabilization of disturbed areas, (6) proper

stabilization of drainage channels; (7) stabilization of drainage outlets; (8) maintenance of existing erosion and sediment

control measures; and (9) tracking or accumulation of sediment on roadways. These criteria generally can be grouped

within the installation and maintenance stages of the evaluation framework outlined above, although most involve

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aspects of both installation and maintenance. The first seven criteria primarily concern installation of BMPs; only two,

maintenance and tracking, primarily concern maintenance.

Inspectors rated each applicable criterion at each site on a scale of Satisfactory, Marginal, Unsatisfactory or not

applicable (NA). Items in compliance with Rule 5 were rated S, items that were in danger of becoming out of compliance

were rated M and items in violation of Rule 5 were rated u. Because all criteria were not applicable at all of the sites,

the number of sites evaluated for with respect to each criterion varies.

Disturbing Results from Disturbed Sites

The results of the inspections are summarized in Figure 1 (Hayes and Matthieu 1998). Overall the results show that

installation is inadequate and that maintenance is worse. Improvements in implementation clearly are needed.

Discussion of each of the nine items reviewed follows.

I Percent Satisfactory Cl Percent Marginal 0 Percent Unsatisfactory 1

Figure 1. Rule 5 Compliance Summary-Percent of Applicable Sites.

Installation of Erosion Control Measures

Erosion control depends upon installation of appropriate control practices in given situations. Examples

of these practices include silt-fence perimeter controls, sewer inlet and outlet protection devices, and the use

of stone or mulch to stabilize slopes. Proper installation of these devices and practices helps reduce the risk

of failure that may result in erosion and off-site sedimentation. Erosion and sediment control measures were

installed correctly at only 32% of the active sites. Installation was marginal at 24% of the sites and had been

done incorrectly at 44% of the sites. Proper installation was marked not applicable in cases where no erosion

control practices were in use.

Perimeter Erosion Control Measures

Perimeter erosion control measures are designed to keep sediment from leaving a site directly at its perimeter

through sheet or gully erosion. Perimeter erosion control devices/practices such as silt fence or buffer strips should be

installed before land disturbance begins. The most effective and cost-efficient perimeter control practice is to leave

existing vegetation in place, especially along waterways. Perimeter measures were installed and in compliance at 48%

of the sites. Marginal conditions were found at 21% of the sites, and 31% of the sites were found to be out of

compliance. Perimeter erosion control measures were not applicable at level or inward-sloping sites.

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individual Building Sites

Under Rule 5, erosion control is the responsibility of the site operator, either the developer or builder, throughout

construction. At some sites, after the infrastructure has been installed and the lots have been sold to individual builders,

the developer no longer has direct control over erosion and sediment control practices on those lots. Builders and

contractors may or may not install and maintain erosion control practices. Erosion control on individual building sites

is a serious problem in Marion County. Erosion and sediment control measures on individual building sites at

developments were found to be adequate at only 9% of the active construction sites. Measures were in marginal

condition at 21% of the sites, and 70% of the sites were found to be out of compliance. Most of these sites lacked proper

construction entrances, storm-sewer protection, and perimeter protection. This category was not applicable for sites that

had not yet begun construction of homes.

Storm-sewer Inlet Protection

Sediment entering storm-sewer inlets significantly reduces the capacity of retention/detention basins and drainage

channels to store and convey stormwater away from flood prone areas effectively. If sediment is not removed prior to

site closure, the specified volume and dimensions of retention/detention basins that were approved by the City can

change. Inlet protection measures are especially important when sediment is tracked into or allowed to accumulate in

roadways where it is conveyed directly to sewer inlets. Using measures such as seeding and silt fence adjacent to inlets

will prevent sediment from clogging inlet protection devices and accumulating in the streets. Storm-sewer inlets were

adequately protected from sediment at just 14% of the construction sites. Sewer inlets were marginally protected at 17%

of the sites, and inlet protection measures were inadequate and not in compliance at 69% of the sites. Inlet protection

was not applicable to sites that had not completed sewer installation.

Stabilization of Disturbed Areas

Stabilization of disturbed areas on construction sites may be the single most important practice for reducing erosion

and off-site sedimentation. The best practice for achieving stabilization is to leave vegetation in place wherever possible.

If soil must be disturbed, stabilization is relatively easily accomplished through temporary seeding or application of

erosion control blanket. Rule 5 requires that disturbed areas that will be inactive be temporarily seeded. Stabilization

by seeding results in higher perceived value by potential buyers, offering developers a financial incentive to vegetate

land as soon as possible once the infrastructure is in place. Of active sites that were visited, 30% were in compliance

with Rule 5 with respect to stabilization of disturbed areas, while 32% of the sites were marginal and 38% were not in

compliance. This category of compliance was not applicable to sites that were being actively cleared or nearly completed

at the time of the visit.

Drainage Channel Stabilization

Ditches and swales designed to convey storm water away from development to natural drainage ways or stormsewers are subject to severe erosion and deterioration if not adequately protected. Erosion and damage to conveyance

channels results in off-site sedimentation of waterways. This can be avoided by stabilizing the soil in conveyance

channels immediately with permanent seeding of grasses, or with stone, mulch, or straw cover. Conveyance channel

stabilization was satisfactory at 44% of the sites, Approximately 23% of the sites had marginally protected channels and

33% of the sites had channels in unsatisfactory conditions. Conveyance channel stabilization was not applicable at sites

that did not have or require channels or at those that did not yet have them constructed.

Outlet Stabilization

Storm-sewer and drainage channel outlets from a site need to be properly stabilized to prevent erosion and

sedimentation of the banks and waters they empty into. Outlet stabilization is best accomplished by protecting the soil

around the outlet with stone riprap, geotextile fabric, or with well-established vegetation. Outlet stabilization was

satisfactory at 73% of active sites. Outlets were in marginal conditions at 18% of the sites and unsatisfactory at 9%. This

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category was not applicable at sites that did not have outlets on the site or where infrastructure development was not

yet completed.

Maintenance of Erosion Control Practices

Erosion control practices that have been installed properly must be maintained to be effective. In most cases, lack

of maintenance results in the same effects as not employing erosion control practices at all. Examples of maintenance

of erosion control practices include removing accumulated sediment from behind silt fence and reinforcing inlet protection

after storms. Failure of erosion control practices allows sediment to leave construction sitesvia storm-sewers, drainage

channels, roadways and sheet and gully erosion, An often-overlooked aspect of maintenance is removal of devices after

work is completed. Maintenance of erosion control practices was satisfactory at only 18% of the sites. Maintenance was

marginal at 27% of them, and there was little or no evidence of maintenance at 55% of the sites. Maintenance of erosion

control measures was not applicable at sites that did not employ erosion or sediment control practices.

Sediment Tracking and Accumulation in Roadways

Soil and sediment in streets and roads are readily washed into sewers and drainage channels and can be a

significant source of pollution. In addition, the sediment can be a traffic hazard with the potential for costly litigation

against the local governments or developers. Sediment accumulated in roads is also unsightly and may discourage

potential home buyers. Tracking and accumulation of soil in roads was kept to an acceptable level at 24% of the sites.

Approximately 28% of the sites exhibited marginal compliance with the rule for keeping roads clear of sediment. Sites

that were out of compliance with the rule made up 48% of this category. Large industrial sites where equipment was

usually kept on site and residential sites that did not yet require extensive coming and going of vehicles were rated not

applicable for sediment tracking.

Off-siie Sedimentation

Sediment is the most abundant pollutant, by volume, in Indiana waters. Residential and commercial development

sites are potential sources of high volume, sudden discharges of sediment that can cause problems for land owners

down-stream of development. Besides the drainage and flooding problems caused by off-site sedimentation, sediment

can obstruct and widen streams and erode stream banks. Sedimentation of the state’s streams and rivers also causes

habitat damage for many aquatic species. There were obvious signs of off-site sedimentation at 21% of the active sites.

This figure is believed to be low, however, due to the large number of sites surveyed in a very short time. Only the most

obvious cases were checked as displaying off-site sedimentation.

Observations and Implications: Priority-problem Solving

A number of observations that have important implications for managers of erosion and sediment control programs

can be drawn from this inspection initiative. First, it is useful to consider the initiative in the more general framework for

effectiveness in erosion control. Indiana regulations for erosion and sediment control first were adopted in 1992. Faced

with implementation of a new regulation with few resources, IDEM, IDNR, and District staff first devoted efforts to

education and ensuring complete coverage and competent planning. In late 1997 and early 1998, program managers

determined that the plan review process was fairly well established and that additional effort needed to be devoted to

installation and maintenance of BMPs. Because resource shortages preclude regular, periodic inspection, IDNRofficials

developed a S.W.A.T. team approach. Teams of state, district, and available municipal officials focused inspection

efforts, visiting and inspecting as many sites as possible in a short time.

In Indianapolis, the results show that implementation generally is poor. Installation of erosion and sediment controls

was unsatisfactory on 44% of all sites, and satisfactory on less than one-third. With the exception of outlet stabilization

practices, which had been installed properly at nearly three-fourths of the sites, no practice was installed properly on

more than half of the sites. Perimeter controls, a basic practice, were installed satisfactorily on fewer than half of the sites

and they were unsatisfactory at almost one-third. Stabilization was satisfactory at less than one-third of the sites, inlet

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protection had been installed properly at less than 15% of the sites, and controls on individuals lots had been installed

properly at just 9% of the sites where they were needed. It is clear that installation is deficient and that additional effort

is needed to ensure that practices identified on plans are installed properly.

The inspections show that maintenance of erosion and sediment controls is even worse than installation. Inspectors

determined that maintenance of controls was unsatisfactory on 55% of the sites and satisfactory on only 18%. Mud is

being tracked on streets and washed into sewers and drainage channels on almost half the construction sites. Additional

field work to ensure proper maintenance of BMPs is a critical need.

Although these results were disturbing, they were not unexpected. Program officials knew that implementation was

inadequate and devised the S.W.A.T. team approach to provide a quick, comprehensive assessment of the status of

implementation. Since the inspections, program managers have used the results as part of overall efforts to increase

understanding of requirements for erosion and sediment control and to build commitment to the programs. City staff

agreed to mail copies of inspection reports to all developers, and the district provided a summary of results to all citycounty councilors.

The results provide information that program managers can use to establish priorities for problem solving and

education. For example, installation of perimeter controls appears better than efforts to stabilize disturbed areas on site.

Future inspections and educational efforts therefore can focus on the importance of stabilization. Similarly, since it

appears that site operators are doing a fairly good job at stabilization of outlets, this requirement can be de-emphasized,

and additional effort can be devoted to solving problems like installation of controls on individual lots that are not

controlled by practices on the larger development site. More generally, as more people understand the different steps

in the process of erosion and sediment control, implementation should become more effective.

The survey did not focus on discovering reasons behind compliance or non-compliance, but several inferences can

be drawn from these data. First, the data and experience indicate that some developers are unaware of their obligation

to control erosion and sedimentation and leave the permitting and erosion control planning to engineers and contractors.

This can result in a lack of commitment to implementation. Second, some developers, engineers and contractors clearly

do not yet understand the purpose and importance of implementing erosion and sediment control practices. Education

is needed to increase their understanding and commitment. Third, some operators know the requirements of Rule 5,

but do not take them seriously, ignoring the Erosion and Sediment Control Plan. For these individuals, enforcement

action may be required. In addition, a general problem that was observed has to do with sequence of construction. All

too often, land disturbance is beginning before erosion and sediment control measures are installed. More emphasis

must be placed on installation of practices prior to earth disturbance, and site operators must learn to follow the sequence

described on plans.

Given that resource shortages are likely to continue, problems in implementation are likely to continue and regulatory

programs are likely to remain less effective than they could be. Steps that may be taken to increase effectiveness

include making sure that the regulated community participates in on-site, pre-construction meetings that underscore the

scope and importance of controls: increasing the visibility of IDNR and District staff and the frequency of their site visits;

educating developers, engineers and contractors about erosion and sediment control practices and how to install and

maintain them; and emphasizing the need for erosion and sediment control throughout the entire development process.

The S.W.A.T. team approach clearly does not solve the problems of a relatively new, understaffed erosion and

sediment control program. But the approach is an effective way to obtain a significant amount of information in a short

time, raise the visibility of erosion and sediment control programs, and help establish priorities for problem solving.

References

Clevenger, B. Miscellaneous unpublished materials. Maryland Department of the Environment, Sediment and Stormwater

Administration, Baltimore, MD n.d.

301
Department of Civil Engineering and the Department of City and Regional Planning. Evaluation of the Norfh Carolina erosion

and sedimentation control program. North Carolina State University, Raleigh, NC, 1990.

Hayes, Jim and Marcia Matthieu. “S.W.A.T. Summary.” Marion County Soil and Water Conservation District, Indianapolis,lN,

1998,

302
Using Constructed Wetlands to Reduce

Nonpoint Source Pollution in Urban Areas

Jon Harbor

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, IN 47907

Susan Tatalovich

FMSM Engineers, Inc.

Columbus, Ohio 43229

Ron Turco and Zac Reicher

Department of Agronomy

Purdue University

West Lafayette, IN 47907

Anne Spacie and Vickie Poole

Department of Forestry and Natural Resources

Purdue University

West Lafayette, IN 47907

Abstract

Potential pollutants carried in stormwater runoff from urban surfaces are a major component of Nonpoint Source (NPS)

pollution. NPS pollution is a leading cause of reduced water quality in US rivers and lakes, and there are major efforts

underway to find innovative approaches to reducing NPS pollution from a wide range of sources, In urban areas, where

much of the land has existing structures, a major challenge is to find ways to retrofit built sites to reduce NPS pollution

associated with stormwater runoff. One component of this may be more widespread use of constructed wetlands that have

value not only in terms of water quality improvement, but also in terms of urban ecology, aesthetics and education.

We have begun a long-term monitoring program of the performance of constructed wetlands in two settings: 1) On

a commercial site where surface runoff is dominated by stormwater flow from parking lots and store roofs, and, 2) On a

golf course that receives considerable surface flow from adjacent commercial, residential and highway areas. Monitoring

includes both continuous measurements of flow, temperature, conductivity, pH and dissolved oxygen, and automated

sample collection during storm events for more complete chemical analyses. Initial results suggest that the commercial

site constructed wetland acts as an efficient trap during the spring and summer for suspended sediment and some

dissolved matter. During the fall and winter dormant season trap efficiencies are much lower, and in some cases negative.

The golf course site constructed wetlands also function as efficient traps during the summer, and plant growth in these

wetlands has been helped considerably by the regular water supply provided by golf course irrigation. Both wetland

systems also provide value in terms of improved aesthetics, their use by local educators, their diverse ecological

assemblages, and the public relations benefits associated with visible efforts at improved environmental management.

Replacing portions of existing parking lots with carefully designed constructed wetlands, and adding constructed

wetlands to urban recreational sites (such as golf courses and parks) should be viewed as one of several elements of an

integrated approach for effective retrofitting urban areas to reduce NPS pollution from stormwater runoff.

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Introduction

One of the major challenges facing urbanized areas is to find ways to improve environmental management in ways

that do not involve major, costly impacts on existing infrastructure. Increasing recognition of the environmental impacts

of built areas on parameters such as runoff amount and quality has increased regulatory and public pressure to develop

and implement effective management practices. However, many of the best management approaches that can be

integrated into the design of new developments cannot be implemented in existing built areas without prohibitive costs.

Thus there is considerable interest in best management practices that can be used to retrofit urban areas for improved

environmental performance.

Wetlands have the ability to store large amounts of water, reducing flooding of surrounding areas and in some cases

recharging groundwater (Mitsch and Gosselink, 1993). In addition, wetlands are capable of improving runoff quality in

many situations (Perry and Vanderklein, 1996) because they trap both solid and dissolved pollutants. Wetlands also can

have considerable aesthetic benefits, and provide habitat for a wide range of plants and animals. Constructed wetlands

are wetlands specifically designed and built for hydrologic and water quality management, as opposed to either natural

wetlands or created wetlands. Created wetlands are designed and built to replace lost wetlands or to compensate for

destruction of natural wetlands. Using constructed wetlands for water treatment attempts to take advantage of the benefits

of wetlands without compromising natural wetland areas.

In urban areas there are unique challenges to be faced in proposing and designing constructed wetlands, Existing

built areas rarely include extensive undeveloped space that can be converted to constructed wetlands. However, there

are several opportunities that arise in many areas, including: 1) Making space by reducing the size of an existing parking

lot; 2) Adding a constructed wetland to a redevelopment or urban renewal project; 3) Adding a constructed wetland to a

park or green space; 4) Adding constructed wetlands to existing recreational facilities such as golf courses. A second major

challenge in proposing constructed wetlands in built urban areas is to maintain adequate hydrology for long-term wetland

survival. The extensive impervious surfaces of built areas generate large amounts of runoff during storm events, but this

water is usually routed quickly away from the built area to prevent flooding. Because there is little opportunity for rainfall

to infiltrate into the soil in urban areas (because most soil is covered by impervious surfaces), shallow groundwater flow

is reduced. This means that wetlands in urban areas will receive far less between-storm water recharge from shallow

groundwater than would be expected for a similar non-urban setting. In essence, wetlands in urban areas will experience

a “flood and drought” hydrologic regime, which is poorly suited to an ecosystem that is based on extensive periods of wet

conditions. One way around this problem is to look for locations where water is applied regularly to adjacent areas, in

particular where extensive irrigation is used. Golf courses and lawns and gardens of major corporate complexes are

potential sites where between storm irrigation might provide excess runoff and soil water drainage to adjacent constructed

wetlands.

Given the potential use of constructed wetlands to improve water quality in built areas, it is important to evaluate how

well wetlands function as pollutant traps in such settings. Such studies can be used to drive design improvements, and

to evaluate the cost-effectiveness of using constructed wetland for NPS pollution control. Although there has been less

work done in the area of stormwater constructed wetlands, in comparison to wetlands used as part of a wastewater

treatment system (e.g. Hicks and Stober, 1989), limited results so far suggest that wetlands can be effective in treating

stormwaterfor nonpoint source (NPS) pollution (Mitsch and Gosselink, 1993; Witthar, 1993; Livingston, 1989). Few data

sets are available because of poorfollow-up of constructed wetland performancethrough appropriate monitoring programs

(Perry and Vanderklein, 1996). However, available studies to date and theoretical reasoning suggest that NPS pollution

control is enhanced by maximizing the distance between the wetland’s inlet and outlet, including deep and shallow sections

in the wetland, selecting vegetation on the basis of climate and water quality and supply conditions, maximizing the ratio

of treatment area to base flow, and minimizing the slope along which the water travels (Horner, eta/., 1994; Witthar, 1993).

The idea in such a design is to model the constructed wetland after a natural wetland, which not only has the ability to slow

down the flow of water (as does a detention or retention pond), but also can remove pollutants from the runoff water. The

most important factor in the design and maintenance of constructed wetlands is hydrology (Mitsch and Gosselink, 1993).

Without the proper water inflow and outflow, the newly created wetland will fail and be unable to accomplish its task of

stormwater treatment.

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Aims and Objectives

We are monitoring the performance of urban constructed wetlands in two settings, a constructed wetland incorporated

into site development for a commercial facility and a series of constructed wetlands built into a recently renovated golf

course that receives runoff from an adjacent urban area. Both sites are in West Lafayette, Indiana. The goal of long-term

monitoring is to provide insight into seasonal and longer-term variations in trap efficiency, both as the basis for improved

scientific understanding of constructed wetland processes and controls, and to form the basis for future improvements in

design.

Study Areas

The commercial constructed wetland site occupies approximately 0.51 ha, with a water surface area of 0.26 ha and

volume of 1300 m3. This wetland is intended to treat the “first flush” of runoff, and so was designed to accommodate the

volume of water corresponding to first half-inch of precipitation on the store‘s impervious surfaces (the parking lot and the

rooftop). The mean depth of the constructed wetland is 0.5 m but this includes two deeper pools with a maximum depth

of 1.8 m (Tatalovich, 1998). Conventional wisdom (which may not be correct) states that 90% of the annual pollutant load

is transported in the runoff produced by the first 1.3 cm of precipitation (known as the first flush), and this has been shown

to be true for the transport of most pollutants over impervious surfaces (Chang, 1994). At this commercial site, runoff that

exceeds the first-flush equivalent is routed to a separate basin.

One motivating force behind use of a constructed wetland on this site was concern over potential impacts on a natural

wetland (Celery Marsh) adjacent to the property. In addition to the constructed wetland, this site includes: elimination of

a proposed auto care center, abstinence from chemical ice-clearing methods, and construction of additional ponds to treat

stormwater runoff that could potentially include harmful pollutants. The constructed wetland receives runoff primarily from

the 4.1 ha commercial parking lot, as well as minor additional input from an adjacent store, local access roads, and US

Highway 52.

The golf course created wetlands are part of Purdue’s new Kampen Golf Course and are positioned to intercept both

runoff from much of the golf course and the adjacent urban area. The developed area includes two residential highways,

a section of state highway, the parking lot of a motel, a gas station, and 200 residences. The water flowing through the

Kampen Course eventually enters Celery Marsh, but prior to reconstruction this water flowed directly through drainage

tiles and overland transport to the marsh, with no treatment. The golf course constructed wetlands serve several purposes:

providing a water hazard and aesthetic component of the course, and enhancing environmental quality that can also be

used in environmental education. Runoff from the urban area travels through three constructed wetlands prior to leaving

the course. One particularly notable aspect of these constructed wetlands is that they have flourished even during long

dry summer periods. Frequent watering of the greens and fairways, common on most courses, has the added advantage

that it provides runoff and tile drainage to the wetlands throughout the summer.

Methodology

To determine the effectiveness of each constructed wetland in trapping potential pollutants, water samplers were

installed at the inlet and outlet of the commercial constructed wetland (Figure l), and at six locations in the golf course

constructed wetland complex to track the progress of water as it enters the course, moves through the wetland system,

and exits to the Celery Marsh. The samplers are equipped with ISCO@ Submerged Probes that measure water levels, used

in conjunction either with a weir or pipe of known geometry. The sampler uses these levels and the corresponding

geometry of the sampling sites to calculate the flow into and out of the wetland. Each sampler also has a YSI@ 600 MultiParameter Water Quality Monitor that measures dissolved oxygen, conductivity, temperature, and pH. The samplers record

flow and water quality parameters every five minutes and are programmed to take water samples during storm events.

Storm sampling is triggered in most cases by a change in water level, and at two locations, by rainfall intensity as

measured with an automatic tipping bucket rain gauge. The trigger points were determined empirically, so that inlet and

outlet samplers begin to sample at approximately the same time. The sampling programs for each sampler are split into

two sections. The interval of time between samples in part A of each routine is closer together than those in the

corresponding part B routines, so that sampling occurs more often during the “first flush.” After that, the second stage

305
Figure 1. Sampling equipment at a constructed wetland. The laptop computer is downloading monitoring data from the sampler, and in the foreground

is a set of 24 sample bottles for storm sampling.

of each routine samples at larger intervals to guarantee samples at times coinciding with the downward slope of the

hydrograph.

Overall, the design of the experiment is to track flow and water quality into and out of the constructed wetlands

continuously, both during storms and between storms, for a multi-year period. This allows for determinations of storm,

seasonal and multi-year trends in constructed wetland trap efficiency. Trap efficiency can be defined in a number of ways,

depending on the likely application of the results. In this work we are interested in concentration trap efficiency (percentage

change in potential pollutant concentration between the inlet and outlet, both maximum and average values) and load trap

efficiency (percentage change in potential pollutant load between the inlet and outlet for given points in a storm, for storm

totals, and seasonally and annually). Selected samples from each precipitation event are analyzed by a Purdue University

laboratory for total suspended solids (TSS), hardness, total Kjeldahl nitrogen (TKN), and total phosphorus (TP). These

parameters are the same as those measured for seven other local sites as part of a larger analysis of water quality in rural

and urban settings. In addition to the analyses performed at the Purdue laboratory, more complete chemical scans are

performed once per season on selected samples by Heritage Environmental Services in Indianapolis, Indiana. The

selection of tests is based on the pollutants that might reasonably occur at each site. The reason for this more complete

scan is to determine whether any potential pollutants not routinely measured at the Purdue laboratory show up at unusually

high levels. Any parameters that were not detected in the Heritage samples could potentially be excluded from future

testing, but those parameters considered to be problems would need to be monitored on a consistent basis in the future.

Results and Discussion

To illustrate possible types of analyses and some major trends in the performance data, without reviewing the entire

data sets available, this discussion includes three examples from the two sites. These include a complete storm record

at the commercial site, between-storm sampling at the commercial site, and first-flush storm sampling at the golf course

site.

Sample Storm at the Commercial Site

A 0.97 cm-storm occurred on 26 October 1997, with a double peak in intensity (Figure 2). As expected, the wetland

acts to damp peak flows, so discharge values at the outlet slightly lag those at the inlet and are lesser in magnitude. Water

temperature in the constructed wetland inlet is high and uniform (no diurnal variations) prior to the storm (Figure 3),

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Total

Hourly

Rnillfall

km) . .f

0.10

0.05

0.00

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Time after Midnight, 25 October 1997 (hours)

Figure 2. Rainfall and inlet and outlet runoff records for a storm event at the commercial site constructed wetland.

MO T--“_-_--..---_-- .--..-____---..-7 16.0

-Temperature (Inlet) ;

...... Temperature (Outlet);

0.0 i

0 5 IO IS 20 25 30 3s 40 4s 50 55 60 65 70

Timesfter Midnight, 25 October 1997 (hours)

14.0

6

12.0 t

e

I

10.0 c

x

E

8.0 k!!h

e

g 6.0 =

t

:.

40 p

d

2.0

25

20

Average

HOWIY

DirTe

(Id cm Is)

10

Figure 3. Dissolved oxygen and temperature records for the storm shown in Figure 1.

drops 6°C during the storm, and slowly climbs back 2°C in the 20 hours after precipitation stops. The outlet temperature

shows a 4°C diurnal cycle prior to the storm, and a lower amplitude cycle after the storm. At the same time, the dissolved

oxygen (DO) values climb during the storm (Figure 3). Inlet DO values vary within the 0 to 4 mg/L range before the storm,

jump up to 9 to 13 mg/L during the storm, and fall during the 24 hours following the storm event. The outlet DO varies from

1 to 8 mg/L prior to the storm, is very stable between 8 and 9 mg/L during the storm, and has strong variations from 3 to

9 mg/L post-storm. High DO values during the storm are due to the increased mixing of the water, which causes oxygen

to be introduced to the wetland, as well as the addition of “new” water that is higher in oxygen to the stagnant water.

307
40 \

Q 30 \

c I

,

0 50 100 150 200 250 300 350 400 450

Time after Start of Sampling (minutes)

5o 1”‘”

. . . . ._ ^ _ . -. . . .“” . . . .--. ,.. . . . . . ...” ,.,..__ _. . ...” ._..........,_..., “...“.” ,__...

40

35

a

30

Y

3 25

3

20

I5

IO

5

0

200

Time after Start of Sampling (minutes)

Figure 4. Total suspended sediment load for the storm shown in Figure 1 (upper), and calculated trap efficiency (TE) if only grab sampling had been

used (lower). The actual load TE for the storm was 84%.

Initially, hardness data from the 26 October 1997 storm showed much higher values for the outlet than the inlet. This

discrepancy relates to the movement of water through the wetland. Soon after the start of a storm, water begins to flow

over the weir at the inlet and inlet sampling begins. This new runoff from the site has a low hardness, reflecting the

naturally low hardness of rainwater. At the outlet, high hardness values show that the water initially being sampled is not

new inlet water being displaced from the wetland; rather it is water that was stored in the concrete outlet box prior to the

storm. Hardness values at the outlet fall throughout the storm, showing that hardness is lower in the wetland than in the

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concrete outlet box. Because hard water occurs when concentrations of Ca” and Mg” are high (Zumdahl, 1989), the

concrete surroundings themselves can add to the hardness of the water. Ninety-five percent of all concrete used is made

from Portland cement, which is prepared using finely ground limestone (Mindess and Young, 1981). The cement is made

into concrete using admixtures such as calcium chloride. Also, the interaction of the surface water with groundwater, which

in this geographic location is very hard due to infiltrating rainwater that dissolves the calcite-rich till from limestone in the

region, can add to the hardness of the water in the wetland (Davis and Cornwell, 1991).

The hardness data suggest that the outlet record probably does not include water that enters and exits the wetland

during the same storm. Other studies (e.g. Bhaduri, et al., 1997) have shown through chemical load distributions that the

inflow and outflow from a basin are actually two different water masses, except in extreme storm events. The only way

that the same water could appear at the inlet and outlet during the same storm would be if the inflow sheeted over the

water in the basin, arriving at the outlet without significantly mixing with the water stored in the wetland prior to the storm;

or if the storm produced enough water to completely displace the volume of water in the wetland.

Total suspended solids (TSS) concentration data and flow values for the storm are used to calculate TSS loading

values, which depict the effect of the basin in reducing the overall sediment load. Total loads depict the actual physical

amount of sediment entering the wetland and are important for planning activities such as dredging. TSS load values for

the inlet are larger than the outlet (Figure 4). The inlet values start high, dip down, and then increase again. This indicates

that the initial runoff has “first flush” (high load) characteristics, and then the load input rate decreases. A second, lower

peak later in the storm could be the result of the later pulse of higher rainfall intensity (Figure 2). The values of TSS at the

outlet remain fairly uniform throughout the storm. The initial value presumably represents between-storm ambient TSS

loading in standing water in the wetland. During the storm, the increase in flow creates more turbulence, which can stir

up some of the bed sediment, slightly increasing the TSS concentration and, therefore, the load. More importantly, though,

the outlet values are lower than those for the inlet; thus there is a net decrease in TSS loading from the inlet to the outlet

for this particular storm. In one sense, this traditional approach is a valid efficiency measure because the water going out

is compared to that going into the wetland, but in another sense it is a skewed picture because the new inlet water is being

compared with “old” outlet water that arrived in the basin during a previous storm (Bhaduri, et al., 1997).

Multiple storm sequence sampling will provide a better view of overall trap efficiency (TE) than a single storm, just

as a complete storm record is better than a grab sample. Standard grab samples do not always lead to accurate trap

efficiency calculations (Figure 4). If one sample were taken each from the inlet and the outlet at exactly same time, the

data could show a very high trap efficiency (30 minutes), no trap efficiency (200 minutes), or a fairly high trap efficiency

(400 minutes). The overall load TE for this analysis was 84%. This is one of the reasons that this particular study samples

several times after the start of a storm -- to bridge the gap between standard grab samples and actual events within the

wetland. Continuous monitoring provides a more complete record of the constructed wetland’s activity, more accurately

depicting the trap efficiency of the wetland. From conductivity data, during the monitoring period, 137 kg of dissolved load

entered the basin, and 59 kg left the basin, for a total dissolved solids (TDS) load TE over the storm of 57%. Further

analysis of many storms can be used to determine an overall trap efficiency over longer periods of time. This type of

analysis could be used to determine the effects of different storm intensities, seasonal variations, and increased

urbanization in the area.

Detailed Chemical Scan at the Commercial Site: Between Storm Conditions

Samples for a detailed chemical scan were taken on 17 December 1997 using the sampler’s grab sampling

mechanism. At this time, there had not been a precipitation event in a couple of weeks, so these samples represent

between-storm conditions in the wetland. Although these samples were tested for many possible pollutants, only a few

were detected (Table 1).

Parameters which show reductions between the inlet and the outlet were chloride, sulfate, ammonia nitrogen, calcium,

magnesium, sodium, silicon, strontium, and total dissolved solids (TDS). For instance, chloride levels fell from 210 to 160

mg/L, calcium levels fell from 95 to 54 mg/L, and strontium levels fell from 0.16 mg/L to below the detection level of 0.10

309
Table 1. Detailed chemical scan of the commercial site constructed wetland. All values are mg/L.

Parameter Inlet

Chloride 210 160

Sulfate 49 37

Nitrogen, Nitrate-Nitrite 0.12 0.11

Nitrogen, Ammonia 0.21 0.14

Chemical Oxygen Demand 18 28

Aluminum BDL 1.3

Calcium 95 54

Iron 0.33 1.7

Potassium 2.5 2.7

Magnesium 28 15

Manganese 0.32 0.24

Sodium 110 85

Silicon 5.1 3.0

Strontium 0.16 BDL

Total Organic Carbon BDL 4.2

Total Phosphorus BDL 0.10

Dissolved Solids 720 490

Total Suspended Solids 4 13

Outlet Detection Limit

2.5

1.3

0.01

0.12

10

0.10

0.10

0.70

0.10

0.10

0.10

0.10

0.10

0.10

7.0

0.03

10

1

Notes: Italicized parameters are those which have an outlet value > inlet value.

BDL = below detection limit

mg/L. Also, TDS levels fell from 720 to 490 mg/L. When compared to the values calculated using conductivity data from

the sampler, these values are slightly higher than the values calculated for the 26 October 1997 storm event. The

maximum TDS values calculated for the inlet and the outlet were, respectively, 568 and 365 mg/L, with average values

around 337 and 263 mg/L. The higher between-storm values could be a result of the ability of sediments to dissolve in

the wetland waters. Reductions in values between the inlet and the outlet indicate removal of certain pollutants within the

wetland and also suggest that at the beginning of a storm, the outlet values will be lower than those of water near the inlet.

Because of this, the best TE should be at the start of a storm, which is shown in the 26 October 1997 storm chemical data.

Not all of the detectable parameters were lower at the outlet than at the inlet. The ones that were actually larger at

the outlet than at the inlet were: chemical oxygen demand (COD), aluminum, iron, potassium, total organic carbon (TOC),

total phosphorus (TP), and total suspended solids (TSS). The increase in TSS is interesting, and may be the cause of

increases in adsorbed pollutants. This could be attributable to the lack of growth of plants in the middle of December.

Plants slow flow within the wetland, allowing sediments in the water to settle, and plants have the ability to take into their

roots pollutants carried by the sediments (Pond, 1995). Because of this, as the plants die, they may release the sediments

and pollutants trapped earlier in the year, as well as releasing products of the decay of the organic matter. Aluminum, iron,

potassium, and phosphorus could have been attached to these sediments, especially the finer particles. Findings such

as these agree with previous studies that noted a distinct reduction in the performance of stormwater wetlands in winter

months (Oberts, 1994; Ferlow, 1993). Not only does plant death have an effect, but also the formation of ice on the water

surface can scour the margins and resuspend the sediments and the pollutants that they carry (Oberts, 1994).

Detailed Chemical Scan at the Golf Course Site

First flush samples were collected for detailed chemical analysis during the first pulse of runoff from a storm in

November 1998 and a second storm in June 1999 (Table 2). In November 1998, 14 water quality parameters declined

in terms of a comparison between the urban input (Site 1) and the golf course output (Site 6). Four water quality

parameters improved between the urban input and the water exiting the course during the same storm. This suggests that

the constructed wetlands were not working well soon after initial construction, during the late fall. However, key

parameters such as ammonia and nitrate-nitrite nitrogen and pesticide levels were either decreased as the watercirculated

through the golf course wetlands or were not detectable at either sampling site.

310
A distinctly different pattern of results is apparent in the June 1999 sampling (Table 2). Fifteen water quality parameters

improved between the urban input and the water exiting the course, and only 4 parameters declined. This suggests that

the golf course’s created wetland system is functioning well to improve the water quality in the late spring when wetland

plants have become established. Two parameters of particular interest for a golf course are nitrate-nitrite N and ammoniaN, which were undetectable in water exiting the course, but at 2.1 and 31 ppm, respectively, in water flowing onto the

course.

Table 2. Detailed chemical scan of the golf course site constructed wetland, selected parameters. All values are mg/L.

November 1998 June 1999

Parameter

Detection

limit

Simazine

Atrazine

Oil and Grease

Chloride

Sulfate

Nitrogen nitrate-nitrite

Ammonia nitrogen

Chem. 0, Demand

Mercury

Total Organic Carbon

Phosphorus

Dissolved Solids

Suspended Solids

Silver

0.10

0.10

5

2.5

2.5

0.01

0.12

10

0.0002

Site 1 Site 6

Urban Created

runoff wetland outlet

BDL BDL

increase/

decrease

BDL

BDL

BDL

+156%

+400%

-95%

-52%’

-8%

BDL

+22%

-11%

+197%

+1606%

BDL

+1771%

BDL

+llO%

BDL

BDL

BDL

+822%

+239%

+238%

+133%

BDL

+51%

BDL

BDL

BDL

+600%

BDL

+56%’

Site 1

Urban

runoff

BDL

0.1

BDL

32

18

2.1

31

480

BDL

240

0.32

240

8

BDL

1.8

BDL

40

BDL

BDL

BDL

1.6

2.2

9.9

0.28

BDL

6.5

BDL

BDL

BDL

2.0

BDL

BDL

Site 6

Created

wetland outlet

increase/

decrease

Aluminum

Arsenic

Calcium

Cadmium

Chromium

Copper

Iron

Potassium

Magnesium

Manganese

Molybdenum

Sodium

Nickel

Lead

Selenium

Silicon

Tin

Titanium

0.03

10

1

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

0.10

BDL BDL

BDL BDL

8.6 22

11 55

1.1 0.06

0.23 BDL

40 37

BDL BDL

8.2 10

0.19 0.17

91 270

17 290

BDL BDL

0.31 5.8

BDL BDL

29 61

BDL BDL

BDL BDL

BDL BDL

0.51 4.7

2.3 7.8

7.1 24

BDL 0.21

BDL BDL

4.5 6.8

BDL BDL

BDL BDL

BDL BDL

2 14

BDL BDL

BDL 0.14

Zinc 0.10

BDL = Below Detection Limit

BDL

BDL

BDL

20

31

BDL

BDL

25

BDL

1.6

0.08

220

2

BDL

0.16

BDL

34

BDL

BDL

BDL

0.26

0.37

28

BDL

BDL

8.7

BDL

BDL

BDL

4.8

BDL

BDL

BDL

-91%’

BDL

-38%

+72%

-100%”

-1 oo%*

-95%

BDL

-99%

-75%

-8%

-75%

BDL

-91%

BDL

-15%

BDL

BDL

BDL

-84%

-83%

+183%

-64%

BDL

+34%

BDL

BDL

BDL

+140%

BDL

BDL

BDL BDL BDL 0.38 BDL -74%’

l where contaminant was BDL, the detection limit was used for % increase/decrease calculations

No unusually high levels of any of a wide array of potential pollutants, including pesticides and metals, were detected

at the golf course sampling sites. However, atrazine was detected in water exiting the neighborhood and entering the golf

course (Site 1). Surprisingly, even from the urban runoff there was no measurable oil and grease. It is reassuring to note

that heavy metals of concern, such as mercury and lead, are below detection limits in all samples.

Conclusions

Constructed wetlands can potentially be used to improve NPS pollution management in urban areas. Although finding

space for constructed wetlands can be a challenge in developed areas, these management tools can be incorporated into

the design of new or renovated commercial and industrial facilities. In some cases, they can be added to recreational

311
facilities such as parks and golf courses. In each of these cases, good initial design and attention to continued water

supply for long-term wetland survival is critical.

The constructed wetland monitoring program in West Lafayette, Indiana, includes both commercial and golf course

constructed wetlands. Selected results presented here illustrate the complexity of developing a program to evaluate

performance of such wetland systems. Traditional grab sampling can provide misleading results compared to continuous

sampling, and it is clear that apparent trap efficiency varies both within storms as well as between seasons. The type of

complete picture of constructed wetland performance that is needed to improve design and enhance understanding of

chemical and biological processes in constructed wetlands can be approached by continuous monitoring through several

years. Initial data suggest that the constructed wetlands studied here are generally performing well to reduce loads and

concentrations of a range of urban NPS pollutants, particularly during spring and summer storm events after wetland

vegetation has become established. However there is also a strong indication that trap efficiencies are much lower, and

in some cases negative, during winter months. The implications of this depend on the context provided by the receiving

area.

Constructed wetlands also provide important benefits beyond water quality control. They provide aesthetic diversity

in urban settings, they represent islands of habitat types that are generally absent or underrepresented in older developed

areas, and they provide important local educational resources in urban areas. Overall, constructed wetlands should be

considered as a potential element of urban retrofit projects, if there are situations where water supply is available to

maintain wetland hydrology.

Acknowledgments

The Purdue constructed wetland monitoring program would not be possible without generous support from the

Showalter Trust, the United States Golf Association, Pete Dye, Inc., and Heritage Environmental. Equally important for

the project has been the willing cooperation of Jim Scott, superintendent of the Birck Boilermaker Golf Complex, Wal*Mart

Inc., and numerous undergraduate and graduate field assistants.

References

Bhaduri, B. L., Harbor, J. M., and Maurice, P. (1997) Chemical load fractionation and trap efficiency of a construction site

storm water management basin. In Environmental & Engineering Geoscience. 3(2): 235-249.

Chang, G. (1994) First flush of stormwater pollutants investigated in Texas. In Watershed ProtectionTechniques. Thomas

R. Schueler, Editor. Herndon, VA: Center for Watershed Protection. l(2): 88-89. From Chang, G., J. Parrish, and C.

Souer. (1990) The first flush of runoff and its effect on control structure design. Environmental Resource Management

Division of Environmental and Conservation Services. Austin, TX.

Davis, M. L. and Cornwell, D. A. (1991) Introduction to Environmental Engineering. New York: McGraw-Hill, Inc.

Ferlow, D. L. (1993) Stormwater runoff retention and renovation: a back lot function or integral part of the landscape?

In Constructed Wetlands for Water Quality Improvement. Gerald A. Moshiri, Editor. Boca Raton, FL: Lewis Publishers,

Inc. [CRC Press, Inc.] pp. 373-379.

Hicks, D. B. and Stober, Q. J. (1989) Monitoring of constructed wetlands for wastewater. In Constructed Wetlands for

Wastewater Treatment: Municipal, Industrial, and Agricultural. Donald A. Hammer, Editor. Chelsea, Ml: Lewis

Publishers, Inc. pp. 447-455.

Horner, R. R., Skupien, J. J., Livingston, E. H., and Shaver, H. E. (1994) Fundamentals of Urban Runoff Management:

Technical and Institutional Issues. Washington D.C.: Terrene Institute, United States Environmental Protection Agency

Livingston, E. H. (1989) Use of wetlands for urban stormwater treatment. In Constructed Wetlands for Wastewater

Treatment: Municipal, Industrial, and Agricultural. Donald A. Hammer, Editor. Chelsea, Ml: Lewis Publishers, Inc. pp.

253-262.

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Mindess, S. and Young, J. F. (1981) Concrete. Englewood Cliffs, NJ: Prentice-Hall, Inc.

Mitsch, W. J. and Gosselink, J. G. (1993) Wetlands. New York: Van Nostrand Reinhold.

Ober-ts, G. (1994) Performance of stormwater ponds and wetlands in winter. In Watershed Protection Techniques.

Thomas R. Schueler, Editor. Herndon, VA: Center for Watershed Protection. l(2): 64-68.

Perry, J. and Vanderklein, E. (1996) Water Quality: Management of a Natural Resource. John Lemmons, Consulting

Editor. Cambridge, MA: Blackwell Science.

Pond, R. (1995) Pollutant dynamics within stormwater wetlands: plant uptake. In Watershed Protection Techniques.

Thomas R. Schueler, Editor. Herndon, VA: Center for Watershed Protection. l(4): 21 O-21 3.

Tatalovich, S.K. (1998). Chemical and Sediment Trap Efficiency of a Stormwater Detention Biofiltration Pond: A Study

of the Wal*Mart Constructed Wetland. Master’s Thesis, Civil Engineering, Purdue University.

Witthar, S. R. (1993) Wetland water treatment systems. In Constructed Wetlands for Water Quality Improvement. Gerald

A. Moshiri, Editor. Boca Raton, FL: Lewis Publishers, Inc. [CRC Press, Inc.]. pp. 147-155.

Zumdahl, S. S. (1989) Chemistry. Lexington, MA: D.C. Heath and Company.

313
Advanced Identification (ADID) Techniques Used to Protect

Wetlands and Aquatic Resources in a Rapidly Growing County

Dennis W. Dreher

Northeastern Illinois Planning Commission

Chicago, Illinois 60606

Abstract

McHenry County, Illinois, approximately 40 miles northwest of Chicago, is one of the fastest growing counties in the

state. It also is home to many valued wetland and stream communities that are threatened by the impacts of new

development. Because of this, county government officials, with funding from the U.S. Environmental Protection Agency,

sought the assistance of resource experts from various local, regional, state, and federal agencies. Their task was to

assess the quality of the aquatic resource and to develop strategies for improved wetland protection. The project initially

involved the development of an up-to-date countywide inventory of wetlands, lakes, and streams. This inventory showed

that over 11% of the county was covered with wetlands and waterbodies. These aquatic resources then were evaluated

and rated based on the habitat, water quality, and stormwater storage functions that they provided. While only a small

fraction of the total number of wetlands -- about 11% -- of the county’s wetlands were designated high quality, these

wetlands represented over 60% of the total wetland acreage. Inventory and assessment data were transferred to a

customized CD-ROM mapping tool to provide ready access to project information by resource managers, planners, and

local governments. The project team also developed a protection strategy for aquatic resources that was tied to the

results of the Advanced Identification (ADID) study. In particular, it identified four critical protection components:

improved education, regulations and best management practices, acquisition, and restoration. Though the ADID study

is only recently completed, there are strong indications that this protection strategy is being taken seriously by officials

in the county.

Background

McHenry County, Illinois lies approximately 40 miles northwest of Chicago along the Wisconsin border. Reflecting

a history of glacial activity, McHenry County possesses an abundance of wetland types in a variety of physical settings.

Predominant wetland types include palustrine, lacustrine, and riverine systems. Palustrine wetlands are found in a wide

variety of geographic settingsand terrains in the county and include marshes, bogs, fens, wet prairies, forested wetlands,

and ponds. Lacustrine wetlands are less common. They are found mostly in eastern portions of the county and are

exemplified by the wetlands of the Fox River - Chain 0’ Lakes. High quality rivers and streams, and associated riverine

wetlands, are relatively common. In fact, McHenry County has some of the highest-quality stream ecosystems in Illinois,

as exemplified by the Kishwaukee River and its tributaries.

While predominantly rural, McHenry County is one of the fastest urbanizing counties in the state. From 1990 to 1998,

its population grew by 31.5% to 240,945. Population is forecast to grow to nearly 362,000 by 2020, an increase of an

additional 50%. This rapid population growth has raised concerns over possible adverse impacts on the county’s

wetlands, lakes, and streams.

Historically, wetland and stream protection measures in McHenry County have included federal regulations, local

government ordinances, and acquisitions by government agencies, primarily the McHenry County Conservation District

and the Illinois Department of Natural Resources. However, with the recent rapid pace of urban development,

unacceptable loss and/or degradation of wetlands and aquatic resources have been observed. Concerned over the

possible environmental effects of rapid growth, the county board invited the U.S. Environmental Protection Agency

Region 5 (EPA) to perform an “advanced identification” (ADID) study of its wetlands and aquatic resources.

314
An ADID project can have several objectives. One objective is to shorten permit processing, while providing

increased predictability to the Corps of Engineers regulations under Section 404 of the Clean Water Act. ADID also

provides information that can be used by state and local governments to aid in zoning, permitting, or land acquisition

decisions. Another objective of ADID is to provide information to agencies, landowners, and private citizens interested

in restoration or acquisition of aquatic sites.

Approach

The ADID study was initiated in 1995, under the coordination of the Northeastern Illinois Planning Commission

(NIPC). The study was a cooperative effort among federal, state, and local agencies to inventory, evaluate, and map

high-quality wetland and aquatic resources in the county. From the federal perspective, the primary purpose of this ADID

study was to designate wetlands or other waters of the United States that are unsuitable for discharge of dredged or fill

material. From the local perspective, the purposes of ADID were to improve the overall protection mechanism for

wetlands via improved local regulation, improved predictability in the permitting process, identification of potential

mitigation/restoration sites, and identification of potential sites for acquisition.

The scope of work for the ADID project included the following tasks:

l form a Technical Advisory Committee and a Planning and Policy Committee;

l develop ADID objectives for McHenry County and a strategy for protection and management;

l identify and map existing wetlands and aquatic resources;

l develop an evaluation methodology for identified functions of wetlands and aquatic resources;

l apply evaluation methodology utilizing Geographic Information System (GIS) technology and field inspection;

l map ADID sites for public review;

l develop a CD-ROM tool that contains both the project data and a customized GIS interface for display, query, and

mapping; and

. produce a final report and brochure and conduct a workshop for local governments, landowners, and consultants.

The Technical Advisory Committee and the Planning and Policy Committee were formed soon after initiation of the

project. There were two general purposes for these committees: 1) provide technical and policy assistance to NIPC and

EPA, and 2) provide a forum for educating local interest groups regarding the value of wetlands and aquatic resources

in the county.

The principal role of the Technical Advisory Committee was to advise project staff on scientific issues, particularly

the development of evaluation methodologies for wetlands, lakes, and streams. Technical committee members provided

expertise in wetland biology, soil science, hydrology, engineering, water quality, and computerized mapping. Technical

committee members contributed substantial time evaluating wetlands, both in the office and the field. The technical

committee consisted of the following invited agencies and organizations:

. U.S. Environmental Protection Agency, Region 5

l U.S. Army Corps of Engineers, Chicago District

. U.S. Department of the Interior, Fish and Wildlife Service, Chicago-Metro Wetlands Office

. USDA, Natural Resources Conservation Service

. Illinois Department of Natural Resources

315
. McHenry County Department of Planning and Development

. McHenry County Conservation District

. McHenry County Soil and Water Conservation District

. Fox Waterway Agency

. Northeastern Illinois Planning Commission

The principal role of the Planning and Policy Committee was to advise project staff on policy, particularly the

determination of wetland functions important to McHenry County. The policy committee also provided advice on the

development of a wetland protection and management strategy. The policy committee included all of the members of

the technical committee as well as members of the following organizations:

. Homebuilders Association of Greater Chicago

. Illinois Audubon Society, McHenry County Chapter

. Illinois Environmental Protection Agency

l Land Foundation of McHenry County

. McHenry County Board

. McHenry County Defenders (a local environmental group)

. McHenry County Farm Bureau

. McHenry County Municipal Association

l McHenry County Realtors Association

9 McHenry County Stormwater Committee

l Openlands Project (a regional open space advocate)

Developing an Aquatic Resource Inventory

Detailed inventories of wetlands, lakes, and streams were developed early in the project. Two principal existing

inventories were considered for identifying and mapping wetlands: the National Wetland Inventory (NWI) developed by

the US. Fish and Wildlife Service with the assistance of the Illinois Department of Conservation (1986) in the early

1980s and an inventory by the Natural Resources Conservation Service (NRCS) that was being completed in McHenry

County just as the ADID project began. While neither inventory was adequate alone (the NWI was becoming dated and

the NRCS inventory, while more recent, and only a data set, focused principally on agricultural areas), in combination

they served as a good starting point. In finalizing the inventory, numerous revisionsand improvements were made based

on reviews of aerials photos, field checks, and the knowledge of local experts.

The resultant inventory identified 2,535 wetlands, including lakes, covering 37,846 acres. The inventory identified

an additional 1,250 farmedwetlands covering 3,839 acres. In total, there were 3,785 wetlands in all categories covering

41,685 acres, or nearly 11% of the county.

Lakes were identified as a subset of wetlands. Specifically, lakes were distinguished based on a criterion of 20 acres

or more of open water. Fifteen such lakes were identified (excluding gravel pits).

316
Type

Wetland

armed Wetland I

Lake

River

I

Number Acreage

2,518 33,003

1,250 3,839

15 3,584

2 1,259

I I

Percent of

County

Area

8.4

1 .o

0.9

0.3

I Total 1 3,785 1 41,685 1 10.6

Streams were identified and mapped based on an inventory developed by the EPA. EPA’s Stream Reach File,

Version 3 (1 :l 00,000 scale), with minor revisions, provided an accurate and complete inventory of county streams. The

inventory included over 570 miles of streams ranging in size from small, unnamed headwaters to large rivers like the Fox

and Kishwaukee.

Evaluation of the Functions and Quality of Aquatic Resources

As the first step in developing a wetland evaluation methodology, members of the policy committee were asked to

identify wetland and aquatic resource functions that were important to McHenry County. After considerable discussion,

the committee recommended that the following functions be considered and evaluated: biological/habitat functions, water

quality mitigation functions, stormwater storage functions, and groundwater functions. These functions then were

evaluated and refined by the technical committee. Ultimately, it was concluded that groundwater functions of wetlands,

while having important water supply implications, could not be evaluated because of insufficient data.

The project team and advisors then proceeded to develop evaluation criteria and methodologies for the following

general categories: biological/habitat functions and water qualify/sformwater storage functions. The development of a

methodology for identifying high-functional-quality wetlands in McHenry County relied both on existing wetland evaluation

methodologies and the technical expertise of members of the technical advisory committee. The resultant methodology

builds on a methodology used in nearby Lake County, Illinois (Dreher, et al., 1992) as well as other documented

methodologies, particularly the Wetland Evaluation Technique (WET) manual (Adamus et al., 1987), the Oregon Method

(Roth et al., 1993), and the Minnesota manual (U.S. Army Corps of Engineers, 1988).

The methodology was designed to accomplish two objectives: 1) identify the functions that individual wetlands were

performing, and 2) identify wetlands of such high quality that they merit special consideration for protection strategies.

The evaluation of the identified functions for individual wetlands can be very complex and some of the referenced

methodologies describe fairly elaborate approaches to perform thorough evaluations. However, because of the large

number of wetlands to be considered in McHenry County, it was necessary to adopt a simpler evaluation procedure.

The resultant methodology isfullydocumented in the final project report, “Advanced Identification (ADID) Study, McHenry

County, Illinois” (NIPC et al., 1998). An overview of the evaluation criteria follows.

Biological functions include wildlife habitat, floristic diversity, stream aquatic habitat, and lake aquatic habitat.

Wetlands were considered high qualityfor this function if they met one of several criteria. These criteria included:

. the presence of threatened or endangered plant or animal species;

l designation in the Illinois or McHenry County Natural Areas Inventory (NAI);

l field evaluation as a grade A, B, or C wetland community following NAI methods;

317
. streams with Index of Biotic Integrity (let) scores of 41 or greater;

l streams with high quality physical habitat; and

. healthy lake ecosystems with rich/diverse fish and plant communities.

Wafer qua/ity/stormwaterstorage functions include shoreline and streambank stabilization, sediment and toxicant

retention, nutrient removal and transformation, and stormwater storage and hydrologic stabilization. In order to be

designated high functional value for water quality/stormwaterfunctions, wetlands were required to meet three of the four

following criteria:

l presence of stabilizing vegetation adjacent to an open waterbody or perennial stream;

l surface area larger than five acres and having characteristics indicating the propensity for sediment/toxicant

retention;

. surface area larger than five acres, upstream of a lake or impoundment, and having characteristics indicating the

likelihood of nutrient removal/transformation; or

l surface area larger than five acres, at least 50% outside the floodplain, and having characteristics indicating

significant stormwater retention.

Alternatively, wetlands could be designated high funcfionalvalueforwaterqualityfunctions if they provided individual

water quality functions adjacent to or upstream of wetlands, lakes, or streams that provide high quality habitat.

Individual wetlands and waterbodies were evaluated using a three-step procedure of GIS screening; aerial photo,

map or desk-top evaluation; and field evaluation (as needed). Based on this evaluation, it was determined that 154

wetlands totaling 17,489 acres, or about 42% of the county’s entire wetland area, met the criteria for high-quality habitats.

Most of the high-quality wetlands tended to be large parcels, averaging 114 acres in size in comparison to the average

wetland size of 11 acres countywide. An additional 274 wetlands totaling 8,292 acres (average size of 30 acres) met

the criteria for high value for stormwater and water quality functions. Thus, while a relatively small number of wetlands

(about 11%) were designated high quality or high functional value, these wetlands represent over 60% of the total

wetland acreage.

Classification

High Quality

Habitat

High Functional

Value

High Quality Lake

Number

154

274

7

Percent of

all Wetlands

4.0

7.2

0.002

Acreage

17,489

8,292

1.346

Percent of Percent of all

County Area Wetland Area

4.5

2.1

0.3

42.0

19.9

3.2

Of the 15 inventoried lakes, seven were determined to be high quality. A total of 572 miles of stream were evaluated

and 170 miles (or nearly 30%) were designated high quality. Interestingly, high-quality stream segments were found on

18 different named streams and rivers scattered throughout the county.

Using ADID for Protection and Restoration

The ultimate measure of success for a project like the McHenry County ADID study is how it contributes to the

protection and restoration of aquatic resources. With this in mind, the project scope included a work element to develop

318
a strategy for protection and management of aquatic resources. With the assistance of the advisory committees, the

project team developed a four-part strategy involving:

. improved education of local government officials, landowners, and the public;

. effective regulations and best management practices;

. expanded acquisition of aquatic sites and buffers; and

l restoration of degraded sites.

This strategy, which is described in detail in the project report (NIPC et al., 1998), is summarized below. Also

described are some recent protection and management activities, although it is still too early to judge the long-term

success of the project.

ImDroved Education: Educational initiatives are critical to improve awareness of wetlands and aquatic resources

among local citizens, land owners, and elected officials. Improved awareness can enhance local support for protection,

acquisition, and restoration programs.

. A 12-page brochure, McHenry County’s Wetlands, Lakes, and Streams, was developed to educate the public and

local officials about the value of wetlands and aquatic resources in their communities. The brochure also

discussed the results of the ADID study and identified additional sources of information and agencies that can

provide help. Over 1000 copies of brochure have been distributed by participating agencies, such as the county

soil and water conservation district.

. Maps and information for all ADID sites were made available on a “user-friendly”CD-ROM. The CD-ROM includes

simplified mapping software developed from a sophisticated GIS tool. The software enables querying and

screening of various wetland characteristics at different geographic scales throughout the county. It also enables

printing out detailed information on individual wetlands. Over 100 copies of the CD-ROM have been provided to

local officials, consultants, and landowners in the county.

. The message of wetland, lake, and stream protection also is being carried to local officials and the public by

county-based environmental groups and consortiums called “ecosystem partnerships” that have been established

for the two main river watersheds in the county (the Fox and the Kishwaukee). ADID will be a useful tool in aiding

the efforts of these organizations.

Effective Rewlafions: Effective regulations are needed to minimize the effects of new development on aquatic

resources. Specifically, improved regulations are needed to fill in the gaps in existing federal, state, and local regulatory

programs. It was the conclusion of both the ADID team and the McJ-lenry County Comprehensive Stormwafer

Managemenf Han (McHenry County, 1996) that improved regulations are needed to address concerns such as buffers

and setbacks, depressional storage volumes, pretreatment of stormwater runoff, and effective environmental mitigation

for unavoidable disturbances.

l Current federal regulations authorized under Section 404 of the Clean Water Act require a permit for the discharge

of dredged or fill material into wetlands or other waters of the United States. Federal guidelines also authorize the

EPA and the Corps of Engineers to identify in advance of specific permit requests, aquatic sites that will be

considered as areas generally unsuitable for disposal of dredged or fill material. The Chicago District of the Corps

has indicated that it will apply this discretionary authority to high-quality habitat and high- functional value sites in

McHenry County. The Corps also generally will require an individual permit (which allows public input) for

proposed modifications of ADID sites.

. Stream and wetland regulations, based on a model ordinance developed by NIPC, also have been adopted by a

number of local governments in the county. These regulations are intended to complement the federal regulations

by discouraging development in buffers and setbacks adjacent to wetlands, lakes, and streams and requiring pre319
treatment of stormwater discharges. The City of Woodstock, the county seat, recently applied its wetland

protection regulations in a residential development review that resulted in an innovative conservation design

around a large wetland. Not only will the wetland be avoided, but the site design calls for clustering of homes and

buffers adjacent to wetland areas. Also, drainage swales and natural landscaping will be incorporated on upland

portions of the site to reduce hydrologic and water quality impacts of the development.

l ADID team members have worked closely with staff and consultants to the McHenry County Stormwater

Committee in the development of a countywide ordinance for new development. It has been recommended that

the countywide ordinance include provisions for stream and wetland protection that complement, but do not

duplicate, federal regulations. While the ordinance adoption process has been challenged by financial constraints

and political changes in the county, it appears likely that significant stream and wetland protections will be added

to existing county and municipal regulations.

Acouisifion: Acquisition of important wetlands and stream corridors is one of the best ways to assure their long-term

protection. In fact, recent experience indicates that these areas are becoming high priorities for public land acquisition.

Information developed in the ADID study, particularly the identification of high-quality habitats and high-functional-quality

wetlands, will be valuable to land acquisition agencies, including park districts, the McHenry County Conservation

District, the Illinois Department of Natural Resources, and local land trusts, in assessing acquisition priorities. In a recent

example, the Plan Commission of Nunda Township in east-central McHenry County is developing a comprehensive land

use plan that will utilize ADID maps to identify areas to be preserved as open space.

Restoration: Restoration of degraded wetlands, lakes, and stream corridors, and ongoing management of higher

quality sites, are critical challenges for land management agencies. Management is needed to counteract the effects

of disturbances such as site fragmentation, elimination of fire, invasive species, and hydrologic alterations. Notably, the

McHenry County Conservation District has been a regional leader in restoring degraded streams and wetlands. The

ADID data base will be very useful in identifying appropriate sites to continue this restoration. The availability of GIS data

bases and mapping, particularly in conjunction with other digital data such as soils maps and data on seeps and springs,

will greatly facilitate this objective.

Lessons Learned

ADID was a valuable experience in McHenry County that generally met its identified objectives. In considering ADID

studies in other areas, there are several important lessons one can learn from the McHenry County experience.

7) Engage localgovernment sponsors andkeep them informed throughout the project. The McHenry County ADID

began after the county board passed a resolution soliciting EPA’s assistance. County staff and elected officials

were invited to participate on advisory committees. When support appeared to waver at critical points in the

process (e.g., staff changes and budget difficulties at the county), the project team reached out by convening

special meetings reminding county officials of the benefits of the project with respect to adopted county objectives.

2) Conduct an open study process involving both traditionalsupporters of stream and weflandprofecfion efforts and

potential adversaries. Groups ranging from environmental organizations to developers and the agricultural

community were invited to participate on advisory committees where issues and approaches were openly

discussed. When a public meeting was held to present project results, over 200 individuals attended. The vast

majority of those expressing opinions indicated support for ADID objectives and procedures, even though some

had concerns over the ramifications of federal wetland regulations.

3) Utilize fhe expertise and local know/edge of federal, sfafe, and local resource agencies. While EPA contracted

with NIPC to coordinate the project, staff from numerous resource agencies contributed invaluable expertise in

hydrology, soils, aquatic ecology, and botany. They also contributed countless hours in evaluating field sites.

Scheduling such assistance from multiple agencies resulted in some time delays. However, without these

voluntary contributions, the project could not have been completed.

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4) Define wet/and and aquatic resource functions from a multi-objective perspective. While there is a tendency

sometimes to focus on just the habitat and recreational values of wetlands, lakes, and streams, it is important to

consider a broader range of benefits to maximize local buy-in to the process. The McHenry County ADID

specifically considered stormwater and water quality functions that were identified as being important in local

plans, such as the McHenty County Comprehensive Stormwater Management Plan.

5) Distribute end-products in user-friend/y formats. While ADID was a highly technical and complex project, efforts

were made to provide products that were readily understandable by local governments, land owners, consultants,

and the public. The product receiving the most interest was the CD-ROM containing ADID data, as well as a

user-friendly GIS-based interface for querying and mapping. The CD-ROM promises to be much more useful

than conventional paper maps.

6) Engage the local press in covering the project. Limited attempts were made to inform the local press during the

course of the study. While there was some resultant news coverage in local newspapers, particularly around the

time of the public meeting, this coverage was not particularly effective in informing the public about the benefits

of wetlands and the importance of the ADID study. Focused efforts, such as targeted press releases, probably

would have improved the frequency and quality of coverage.

Conclusions

The ADID study provides valuable information to advance the protection and restoration of wetlands and aquatic

resources in McHenry County. It can aid residents and organizations desiring to protect high-quality resources or restore

sites that have been degraded. It can inform landowners and developers about an appropriate course of action when

they are considering disturbances in or adjacent to high-quality sites.

While the final ADID products have been available for only a short time, it is apparent that they will greatly facilitate

ongoing efforts to educate county residents and officials, protect streams and wetlands from the effects of new

development, preserve sensitive stream corridors and wetlands as public land, and restore degraded sites. While the

ultimate success of county stream and wetland protection initiatives will depend on the will of landowners and local

government officials, no one will be able to blame wetland loss on inadequate information.

References

Adamus, P., E. Clairain, R. Smith, and Ft. Young. 1987. Wetland Evaluation Technique (WET). Department of the Army,

Waterways Experiment Station, Corps of Engineers, Vicksburg, Mississippi.

Dreher, D., S. Elston, and C. Schaal. 1992. Advanced Identification (ADID) Study, Lake County, Illinois. For U.S.

Environmental Protection Agency, Region 5.

McHenry County Stormwater Committee. 1996. McHenry County Comprehensive Stormwater Management Plan.

McHenry County, Illinois.

Northeastern Illinois Planning Commission, U.S. Fish and Wildlife Service - Chicago-Metro Wetlands Office, and U.S.

Environmental Protection Agency, Region 5. 1998. Advanced Identification (ADID) Study, McHenry County, Illinois.

Roth, E., R. Olsen, P. Snow, R. Sumner. 1993. Oregon Freshwater Wetland Assessment Methodology. Oregon Division

of State Lands.

U.S. Army Corps of Engineers, St. Paul District. 1988. The Minnesota Wetland Evaluation Methodology for the North

Central United States.

U.S. Department of the Interior, Fish and Wildlife Service, in cooperation with the Illinois Department of Conservation.

1986. National Wetlands Inventory.

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Local Government Involvement in Mitigation Banking

Lisa T. Morales

Wetlands Division

U.S. Environmental Protection Agency

Washington, D.C.

Abstract

Mitigation banking is a valuable tool that can be used by local officials to achieve wetlands restoration and other local

goals. Mitigation banks can be established by local governments to provide compensation for wetland losses that result

from development projects. There are different strategies that local governments can use to establish a mitigation bank,

depending upon their goals and objectives. The success of a mitigation bank is dependent upon several factors, ranging

from bank location to the availability of funding. The Environmental Protection Agency conducted a survey of local

jurisdictions to identify the different strategies that were utilized for effective development and implementation of

mitigation banking. The findings of the survey are presented in case-studies that characterize the approaches that were

used by local governments to achieve their mitigation banking goals and objectives.

Introduction

Mitigation banking is defined in the Federal Mitigation Banking Guidelines’ as “wetland restoration, creation, or

enhancement for the purpose of compensating for unavoidable wetland losses in advance of authorized impacts to

similar resources.” Under Section 404 of the Clean Water Act, applicants for permits must first avoid and minimize all

impacts to wetlands and other waters of the United States. If there are still impacts, then applicants must provide

compensatory mitigation through the restoration, creation, and the enhancement of similar type of aquatic resources.

This “sequencing process” under the Section 404(b)(l) guidelines is a central premise of the Section 404 regulatory

program, and mitigation banking can play a role in providing compensatory mitigation for unavoidable wetlands losses.

As a general matter, on-site and in-kind mitigation is preferred under the Section 404 Program. However, in those

circumstances where it is determined, on a case-by-case basis, not to be practicable, then off-site, in-kind mitigation is

acceptable.’ Off-site mitigation can be accomplished using a federally-approved mitigation bank. Since the use of

mitigation banking to offset permitted wetlands losses began in earnest in the early 1990’s, local governments have been

involved in developing banks to restore and replace lost wetlands functions and values within their jurisdictions. By

simplifying the process for compensating for unavoidable wetlands losses, appropriate use of the banking concept can

improve both permitting efficiency and environmental protection.

’ Federal Guidance for the Establishment, Use and Operation of Mitigation Banks; Notice. Federal Register, Volume 60, No. 228, pages 58605-58614,

November 28,1995.

’ Memorandum of Agreement between the EPA and the Department of the Army Concerning the Determination of Mitigation Under the Clean Water

Act Section 404(b)(l) Guidelines (February 6, 1990)

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Mitigation Banking Objectives

l Local needs are best met when there are clear objectives and goals for establishing a mitigation bank. Examples

of objectives for mitigation banking identified by local governments include:

l Use as part of a comprehensive watershed plan that addresses urban development and the need for preservation

and restoration of wetlands

l Provide an incentive for economic growth by streamlining the process for providing compensation of unavoidable

wetlands impacts

. Provide for restoration of degraded wetlands that otherwise might not be improved because of insufficient funding

l Use as part of a multi-objective strategy to manage stormwater, flooding, water quality, etc.

l Compensate for wetland losses from future local agency projects

Types of Mitigation Banks

Once the objectives for the proposed bank have been established by the local agency, the type of bank to meet the

identified objectives must be determined. Local governments can establish a mitigation bank for their individual use or

for credit sale as a commercial venture. The bank can be established solely by a public agency or as a joint venture with

a private entity (e.g., entrepreneurial business). Mitigation bank types need not be mutually exclusive; for example a

commercial mitigation bank may be established through public/private partnerships and still be part of a watershed

management plan.

Commercialbanks: A commercial mitigation bank is one in which the credits are sold to a party other than the bank

sponsor (banker). The banker sells credits within the established service area to permittees who have approval from

the U.S. Army Corps of Engineers (Corps); the agency responsible for issuing wetlands development permits; to

compensate for wetland impacts through a mitigation bank.

Sing/e-user: A single-user mitigation bank is established by a local agency to compensate only for wetland losses

associated with activities conducted by the agency.

Factors Contributing to Mitigation Bank Success

Conditions for successful bank establishment

Local governments which have successfully established a mitigation bank have identified several conditions that

need to be considered in order to successfully meet environmental and/or economic objectives.

l There must be a demand for compensatory mitigation within the local jurisdiction. Demand results from

development pressure in a rapidly growing area where impacts to wetlands are expected to occur. The value of

development in regions with rapid growth increases the willingness of the public agency or developer to pay for

wetland mitigation. Potential bank sponsors should conduct a “needs” analysis to determine the demand for a

mitigation bank in a given area. The analysis will show the extent of potential wetland impacts in the region and

whether mitigation banking is a viable compensation option. Once demand for a bank is decided upon, the size

of the bank can be determined.

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l There must be a sufficient supply of available sites for restoration, creation, enhancement, or preservation.3 The

availability of appropriate sites will vary by geographic region. For example in Florida, large tracts of degraded

wetlands have been impacted by previous land-use practices and by invasion of exotic plant species. Such large

areas are conducive to restoration and enhancement. In some areas, there are mitigation banks where property

is in high demand, resulting in high land acquisition costs. In other circumstances, finding an appropriate site

may be difficult due to the lack of large wetland expanses. Land that is in public ownership can help lessen land

acquisition cost, but may not have favorable physical attributes that would allow for a mitigation bank to be selfsustaining over time.

l Finally, regulatory coordination is important. The local agency needs to provide a prospectus to the Mitigation

Banking Review Team (MBRT) established by the local Corps district.4 The prospectus will serve as the mitigation

banking instrument that identifies the objectives and administration of the proposed bank. As pat-t of this

coordination process, the local agency should identify the proposed bank site, the geographic service area,

wetland types suitable for compensation at the site, the debiting and crediting system, performance standards,

monitoring plan, contingency and remedial actions, and provisions for long-term management and maintenance.

+ Proposing a mitigation bank in the context of a regional plan that integrates the bank into a comprehensive

wetland or watershed management strategy may improve the likelihood of acceptance of the prospectus by

the MBRT. A watershed management plan can provide greater certainty about the nature and extent of future

wetland impacts and identify the most appropriate, environmentally beneficial options for offsetting the

anticipated impacts. In this way, the MBRT has a level of assurance that the bank is a part of a broad goal

to maintain or gain wetland functions in a given area or watershed.

Site selection criteria

Local agencies need to carefully consider the sites that are identified for potential mitigation banks. Site selection

is one of the most important criteria affecting the successful establishment of a mitigation bank. The most significant site

selection criteria is the potential that the site can be successfully restored or enhanced in a manner that will provide

appropriate compensation for anticipated unavoidable wetlands losses. Selection of such ecologically important or

desirable sites can further regulatory acceptance.

As identified in the federal guidance on mitigation banking, mitigation sites should be self-sustaining over time. Sites

with naturally occurring hydrology are preferable to sites that require complex hydraulic engineering features that are

costly to develop, operate, and maintain. Therefore, sites that can be restored without complex improvements should

be the first option when establishing a mitigation bank.

Ideally, site selection would be undertaken in accordance with a watershed management plan under which existing

wetlands have been surveyed to determine which sites are the highest priority for protection, the most suited for

restoration or enhancement, and the most likely to be impacted by development. Through watershed planning, wetland

functions that are lacking in a region can also be used to guide site selection. Additionally, planning at this level can help

determine compensation requirements, because anticipated wetland impacts can also be identified. Two federal

programs, the Special Area Management Plan (SAMP) and the Advance Identification (ADID) Program, can provide

guidance and technical assistance to local sponsoring agencies that meet certain criteria and are interested in

establishing a watershed scale planning effort.

3 The Federal Mitigation Banking Guidance states that the use of preservation in a mitigation bank may be authorized by the federal agencies when

it is demonstrated that the preserved areas contribute to the functions of the restored, created or enhanced aquatic resource.

4 The Mitigation Banking Review Team is established as consistent with the Federal Mitigation Banking Guidance.

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Mitigation bank site selection can also be targeted to address specific environmental objectives. For example,

wetlands in several counties in Florida were overrun by exotic vegetation. Mitigation banking provided the funds to

improve the wetland habitat through exotic species eradication and revegetation with native plants.

Site selection may also be influenced by a regional demand for mitigation opportunities and the availability of suitable

restoration sites. Land acquisition is often cost-prohibitive for local agencies: land ownership, zoning restrictions, and

allowable uses also are important factors in determining a mitigation bank site. Important functional characteristics of

a potential restoration site include the presence of hydrology, hydric vegetation, and/or hydric soils; size of the site;

historic conditions; and the degraded condition of existing wetland (e.g., exotics, fill, compaction, trash). Experts in

restoration should be consulted regarding specific wetland requirements and regional wetland attributes prior to site

selection.

Funding

The most common funding option used by local governments is the advance-credit sale option addressed in the

Federal Mitigation Banking Guidance.With this funding mechanism, advance sale of a percentage of the total credits is

allowed after certain criteria have been met by the bank sponsor, such as conservation easement, land acquisition,

and/or design plan approval. By selling a limited number of credits in advance, the banker can collect sufficient funds

to begin conducting wetland improvements, then sell more credits as they are certified by the regulatory agency. The

advance sale of credits, however, involves a degree of risk; for example, problems can arise prior to mitigation bank

implementation or completion, leaving the bank sponsor liable for any credits sold.

Local governments have also identified various other strategies for funding the establishment of their mitigation

banks. Some of the options include:

l Completing the project in phases so that initial credit sales will provide funding for the remainder of the project

l “Borrowing” money from other local agency funds, then paying it back using money from credit sales

. Using available federal or state grant money for wetland improvement as seed money to establish the banks;5

. Partnering with a private company to share the costs

l Using combinations of the above mechanisms

Bank Administration and Operation

Several issues related to bank administration and operation pose a challenge to local governments. The geographic

service area, credit ratios, credit valuation, monitoring plans, and long-term maintenance provisions are all issues that

must be addressed by the local sponsor and approved by the signatory agencies. Information on these issues can be

found in the Federal Mitigation Banking Guidance mentioned earlier, as well as in any existing state guidance. A

partnership with a private entity that has experience in mitigation banking is one alternative for addressing bank

administration and operation challenges.

The geographic service area for the mitigation bank should be established and presented in the mitigation banking

planning document. The service area is the area in which credits from a mitigation bank can be used to compensate

for unavoidable wetland losses. This area can be a watershed or a political boundary, such as a county or municipality.

The number of credits produced by a mitigation bank are generally determined by two factors, (1) the number of

acres restored, created, enhanced, or, in exceptional circumstances, preserved, and (2) a quantified evaluation of the

5 EPA has also identified the State Revolving Fund (SRF) as another potential source for funding the establishment of mitigation banks, subject to

approval under each State’s SRF regulations.

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functional value of the wetlands in the bank. As a general matter, the greater the wetland improvement, the more credits

generated. For example, more credits may be associated with restoration and fewer credits associated with

enhancement. The second factor involves a functional assessment of the improved or created wetland, and a method

for converting the functional units to credits.

To determine the appropriate compensation requirements for wetland losses, a mitigation ratio must be developed.

This ratio can be based on lost wetland function and area, the rarity of the affected wetland, and the wetland replacement

kind and function. The ratio will determine the number of credits required from the bank to replace the impacted aquatic

resource. Generally, the mitigation ratio is greater than or equal to one; i.e., at least one credit (acre of restored,

enhanced, or created wetlands) required to replace one acre of lost wetland resource.

As a general matter, the bank sponsor monitors the bank for a period of time (e.g., five years) to determine whether

the bank is functioning at the level required by a previously determined set of performance standards established in the

banking instrument. After the performance standards are met, the local agency may choose to transfer the mitigation

bank to another entity (e.g., land trust) for the long-term maintenance and monitoring. An agency can also use volunteer

labor to offset costs of monitoring and maintenance and to improve public awareness and citizen stewardship for the

project. Among the local bank projects reviewed by EPA in the survey, loca.1 sponsors were usually responsible/liable

for the performance of the mitigation site from the beginning, or after an established period of time if the project was a

joint-venture.

Financial assurances for long-term maintenance and contingency plans for the bank most often take the form of

additional fees added onto the cost of a credit, with a fixed amount from the sale of each credit put into an escrow

account. The local agency then draws from the account for necessary maintenance expenditures. In some cases,

completed banks become part of a park system or are turned over to a public agency for long-term management.

Mitigation Bank Approaches with Case-Study Examples

The following case-studies are examples of the different types of mitigation banks that can be established by a local

agency, and highlight specific issues that are of concern to local governments. The banks discussed in the case-studies

are not mutually exclusive, in that a given bank may fit into more than one “bank type” category.

Mitigation Banking in the Context of a Watershed or Wet/and Management Plan

Local governments can use a watershed or wetland management plan as a means of addressing economic

development and environmental concerns. An important aspect of such a plan involves compiling an inventory of

existing wetlands in order to determine both coverage area and functions provided. This information can then be used

to protect important resources, establish areas suitable for development, and determine the best sites for restoration.

Mitigation banking is, therefore, a tool that can be integrated into a watershed plan to help meet resource management

objectives.

Advantages of mitigation banking in the context of a watershed management plan are as follows:

l Sites to be restored and critical sites to be preserved are already identified in the plan

l Market demand for compensatory mitigation can be identified

l The extent and nature of potential impacts have been determined

. Likelihood of restoration project success is improved

l Uncertainty for regulatory agencies is lowered

l Multiple objectives can be attained

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l Environmental benefits are maximize

West Eugene Mitigation Banking Program

Overview: The Eugene Wetland Mitigation Bank Program (Bank) was established in 1995. The program is operated

by the City of Eugene, Oregon, under a separate fund within the City’s financial structure. The goal of the Bank is to

provide a mechanism to fund wetland mitigation projects, carry out the West Eugene Wetlands Plan (Plan) adopted in

1992, and meet other community needs. This program is being conducted in cooperation with the City’s wetland partners

(the U.S. Bureau of Land Management [BLM] and the Nature Conservancy [TNC]).6 The objectives that the City seeks

to accomplish with the mitigation banking program include:

l Creating credits in advance of wetland losses

l Meeting the mitigation needs of the community of Eugene

l Achieving community objectives, such as increased flood storage capacity, enhanced water quality, improved

wildlife habitat, and establishment of education and recreation opportunities

l Targeting areas with high prospects for restoration success such as historic wetlands, disturbed agricultural

wetlands, and areas adjacent to waterways

l Communicating the banking program’s value to the community

l Operating the bank as part of a national model wetland program in cooperation with the wetland partners

. Establishing a permitting process familiar to businesses, environmental interests, and regulatory agencies

Funding for identifying wetland areas for the bank was provided through EPA’s Advanced Identification (ADID)

program. The West Eugene Wetlands Plan integrates wetlands protection and community development needs by

identifying areas best suited for wetland preservation and areas with development potential. Thirteen hundred acres of

wetlands were identified within the plan area, with more than 1,000 acres designated for protection or restoration and

approximately 300 acres of lower value wetland designated as suitable for future fill and development. The Plan calls

for the establishment of a mitigation banking program to compensate for unavoidable losses of wetlands through

restoration and enhancement in conjunction with protection of important wetland resources.

All mitigation bank projects will be located within the Long Tom River watershed. Seven projects were initially

constructed for a total of 56 acres. Three additional projects totaling 60 acres were in planning at the time of the EPA

survey.

In this program, mitigation bank credits can be established in three ways

1. The City or its partners may undertake wetland mitigation work, then seek certification of credits by the Corps and

Oregon Division of State Lands (DSL). The City provides documentation on a site prior to the mitigation work and

after completing improvements to demonstrate an increase in wetland values.

2. The City may create more credits than are needed to compensate for permitted wetland losses as part of

concurrent or advance mitigation work. If the Corps and DSL certify the excess credits, they will be added to the

Mitigation Banking Program’s ledger for sale.

3. Uncertified credits may be sold in order to fund initial mitigation work, which are later certified by the Corps and

DSL when the initial hydrological and vegetative work is completed.

6 City of Eugene, Public Works Department. 1997. West Eugene Wetland Mitigation Bank, Annual Report 1996.

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The City Stormwater Fund provided money for acquisition of site properties. Additional capital for the projects came

from the sale of uncertified credits. No uncertified credit can be sold unless the Corps and DSL have approved a

mitigation plan.

As the bank sponsor, the City is responsible for monitoring and maintaining the bank sites. Monitoring is required

for a minimum of five years and the sites will be inspected by the Corps and DSL on an annual basis. Monitoring goals

are determined on a site-by-site basis. Maintenance will be conducted to ensure that the wetland functions and values

are fully established and functioning. If the site is not meeting the performance criteria, corrective measures will be

taken. Funding for these tasks is included in the credit price. At least an additional 20% will be added to the estimated

credit cost and set aside to be used to monitor, maintain and, where necessary, conduct remedial measures.

Single-user Mitigation Bank

Local governments can establish a single-user bank. In this case, the local government initiates the bank, creates

the credits, and is the principal credit user. Local sponsors with long-range project plans that involve potential impacts

to wetland areas may establish a mitigation bank or banking program in anticipation of the need for compensatory

mitigation. For example, a public works department with road expansion plans may know in advance that there will be

unavoidable impacts and provide the funds necessary to initiate a bank in anticipation of the project.

An advantage of a single-user bank is that long-term planning provides advance knowledge of potential wetland

losses associated with future projects. This reduces the uncertainty surrounding the demand for the bank and eventual

funding. Funding may be available to initiate the bank based on the predicted future use.

Snohomish County Airport Mitigation Banking Program

Overview. The Snohomish County Airport (SCA) needed to address the multiple objectives of their 20-year Master Plan,

the aviation needs of the airport, the economic growth of the region, and environmental protection. The Master Plan

identified three development/construction projects that will occur over five years, each with anticipated wetland impacts.

The objectives that the SCA seeks to accomplish through the banking program include:

l Creating a mitigation alternative for projected airport development

. Replacing or augmenting wetland functions in the watershed

l Replacing habitats that will potentially be lost, including open-water habitat that cannot be created on-site

l Creating recreational and educational opportunities

The SCA analyzed the three watersheds containing the project areas to determine missing wetland functions and

values. Potentially impacted wetlands were then characterized according to acreage, wetland category, and function.

Based on these analyses, two mitigation banks were designed to replace the wetland functions that would be lost by the

airport projects. The SCA banking program creates a “reserve” of mitigation that accommodates Master Plan impacts

for approximately seven years.7

Mitigation banking was an effective alternative for the SCA since the Federal Aviation Administration (FAA) prohibits

the creation of bird attracting habitat within 10,000 feet of a runway. In this circumstance, on-site mitigation was

determined not to be a viable alternative as it would attract waterfowl and migratory birds. The SCA created or enhanced

a total of 32 acres and preserved an additional 23 acres.

Following a format developed by the Washington State Department of Transportation, the SCA Memorandum of

Agreement (MOA) was established. The MOA describes the procedures for selecting, managing, monitoring, and

7 Snohomish County Airport. 1997. Snohomish County Airport MOAfIM Executive Summary.

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protecting mitigation banks. Additionally, an Implementation Manual was created by the SCA that presents agency

recommendations for approval of the two specific bank sites. A technical oversight committee reviewed and advised

changes to the MOA, and provides input for credit evaluation and ratio development.

Construction is nearly complete at both sites. One site has a nonprofit organization associated with it called the

Friends offbrbeck Wetland Sanctuarythat is working to promote citizen stewardship, protection of wildlife and wildlife

habitat, native plant propagation, and environmental research.

Primary funding for the mitigation banks came from airport revenues. In addition, some funds were provided from

the FAA, since the program will be used to mitigate for projects required by FAA safety regulations.

The SCA will be responsible for one of the sites in perpetuity. The other site will be donated to the City of Everett,

Washington, Parks Department after all of the credits have been used. Monitoring will be conducted for five years in the

emergent wetland and ten years in the forested wetland. Both sites have been placed in a conservation easement and

a contingency plan will be executed if performance criteria are not met.

Public/Private Joint Venture

Public/private joint ventures can facilitate mitigation-bankestablishment by providing investment capital and technical

expertise. Mitigation banking is a complex process involving aspects of design, engineering, regulation, project

management, biology, ecology, marketing, and long-term management. Because of this, a mitigation banking joint

venture may be established to share the responsibilities and costs. A local agency role may be bank sponsor, bank

creator, land owner, long-term manager, or all four. The private entity may conduct only the technical work, but can also

assume any of the aforementioned roles. The EPA survey found that the local agencies partnered in joint ventures were

most likely to provide the land for the mitigation bank and the private entity would provide funds and/or technical

expertise.

City of Pembroke Pines and Florida Wetlandsbank, Inc.

Overview: In 1992, the City of Pembroke Pines in Broward County, Florida, entered into a partnership agreement

with Florida Wetlandsbank, Incorporated to restore a heavily degraded site that was already overrun by exotic species

and becoming further deteriorated by all-terrain vehicle use and illegal trash disposal. The City did not have the

resources necessary to restore the site or to establish a mitigation bank. Concurrently, development pressures in the

area were creating a demand for an effective mitigation alternative.’ Florida Wetlandsbank agreed to design and

construct a wetland system by eradicating the exotics and replacing them with a mixture of 10 typical Everglade habitats

including cypress stands, emergent marshes, tree islands, and sawgrass prairie. Florida Wetlandsbank also provided

the management for the bank, selling the first credits in 1994. In 1997, restoration was near completion, with 396 credits

sold. The objectives for the Florida Wetlandsbank (the name of the mitigation bank) are to:

l Provide a mitigation alternative for the rapidly urbanizing City of Pembroke Pines

l Provide mitigation at a large site with high potential for ecological success

l Restore native wetland ecosystems in an area that was degraded and infested with exotic species

The mitigation bank provided a number of economic and environmental benefits, including the following.

’ Paul Wattles, Assistant City Manager, City of Pembroke Pines, Florida. Personal communication, March 23, 1998.

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l The project provided revenue for the City through the collection of franchise fees per acre (paid by Florida

Wetlandsbank, Incorporated after credits were sold).

l Developers used the credits as quickly as they became available.

l The City plans to open part of the area as a park and offer public access and passive recreation opportunities.

l To date, the site is ecologically successful, with little reinfestation of exotic plants.

l Florida Wetlandsbank, Incorporated profited from the sale of credits.

The construction is completed and all credits sold for the original 350-acre site. An additional 100 acres has been

added to the site with construction nearly completed and credit sales pending. The service area for the mitigation bank

was kept at the county level rather than the basin level, which incorporates three counties. The County determined that

mitigation for wetland losses should remain within the county.g The number of credits available in the mitigation bank

were determined using a modified Wetland Rapid Assessment Procedure (WRAP).

Florida Wetlandsbank, Incorporated provided the capital for initiating the bank. Pre-project sale of credits allowed

restoration work to begin. A trust fund was established to provide for the long-term maintenance of the site, with $1,000

per credit contributed to the fund.

Site monitoring will be conducted by Florida Wetlandsbank, Incorporated from the time that construction is completed

for five years. Quarterly monitoring reports are required by the SFWMD. These reports contain information regarding

the banks performance criteria. A performance bond was placed with the SFWMD for each stage of construction. The

bond will be used in the event that any of the performance criteria are not met. Once the performance criteria for the

site are met, the money will be released to Florida Wetlandsbank.

Commercial Mitigation Banking

A local government can establish a commercial mitigation bank that sells credits to anyone who meets the

requirements to use the bank for compensatory mitigation. The bank discussed here was established on public land,

solely by public agencies, with credits for sale to the public. Optimally, a public commercial mitigation bank is part of a

larger watershed plan.

A major advantage of public commercial banks is that they are in public ownership, which can better provide longterm management, and the funds generated from the bank can be used to further improve public resources. The

disadvantage is that the up-front capital investment can be difficult for public agencies with limited availability of funds

DuPage County, Illinois

Overview DuPage County is a highly urbanized area located west of Chicago. Land development has negatively

impacted the natural drainage system of the area by eliminating naturally occurring storage, reducing stormwater

infiltration, and increasing the velocity and quantity of runoff. In response, the DuPage County Stormwater Management

Plan (Management Plan) was developed in 1989, to reduce the potential for recurrent and increasing flood damage and

to reduce further environmental degradation associated with development. The ecological assessment conducted during

development of the Management Plan found that wetlands represented a significant portion of the natural watershed

’ Desmond Duke, Project Administrator, Florida Wetlandsbank. Personal communication, June 19, 1998.

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storage in the county, and are essential for adequate stormwater retention, conveyance, sediment control, and water

quality enhancement.”

Individual watershed plans, within the larger DuPage County management plan, were developed to identify wetlands

for protection, enhancement, and restoration. The County attempts to establish mitigation banks in the four main

watersheds within the County. The service area for each bank will be the watershed in which the bank is located. The

County also established an ordinance for stormwater management that requires developers whose development

proposals will affect the function and values of wetlands to consider mitigation banking as an alternative to compensatory

on-site mitigation. The objectives of the DuPage County commercial mitigation banking program are to:

l Manage and mitigate the effects of urbanization on stormwater drainage

l Enhance the quality, quantity, and availability of surface and groundwater resources and prevent further

degradation

l Preserve and enhance existing wetlands, aquatic, and riparian environments

l Encourage restoration of degraded areas

Any investment in a bank must be at least equal to the cost of planning, acquiring lands, constructing, and operating

and maintaining mitigated wetlands of equivalent or greater functional value than those lost to development.

The land for the bank sites was in public ownership. Funding for establishing the bank and initial project work came

from an advanced credit sale. One-third of the credits were allowed for sale prior to work beginning at the site. One site,

Winfield Creek, was in the process of selling credits for project initiation when public opposition to the site halted the

project. The County is now in the process of finding another site but, in the interim, is liable for the credits sold.

The County has five banks that have been approved by the agencies and are in various stages of implementation.

The oldest project, Cricket Creek, is in year two and, to date, is exhibiting successful hydrologic and vegetation

conditions.

Conclusion

The use of mitigation banking by local governments can be an effective tool to restore and protect their community’s

valuable wetlands resources. The case-studies presented provide local governments with different mitigation banking

strategies that could be used to address the needs of their community. As demonstrated in the case-studies, the

establishment of sound objectives and goals by the local agency will help determine the type of mitigation bank that will

best meet the local needs. In addition, there are several conditions that local governments must evaluate and consider

for successful bank implementation, including (1) a demand for compensatory mitigation, (2) a sufficient supply of

suitable sites for the bank, and (3) opportunities for working in partnership with the federal and state regulatory and

resource agencies.

Mitigation banks that are established by local governments can address more than just the need for compensatory

mitigation. Wetlands mitigation banks can achieve additional community needs by increasing local flood storage

capacity, improving wildlife habitat, and providing educational and recreational benefits while restoring and enhancing

important wetland resources.

lo DuPage County Stormwater Management Committee. 1989. DuPage County Stormwater Management Plan. DuPage County, Illinois.

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Massachusetts Stormwater Management Policy/Regulations:

Development, Implementation, and Refinement

Bethany Eisenberg

Vanasse Hangen Brustlin, Incorporated

Watertown, Massachusetts

Abstract

In March of 1996, the Massachusetts Department of Environmental Protection, in conjunction with the Massachusetts

Office of Coastal Zone Management, released the Draft Version of the State’s Stormwater Management Policy. The Policy

includes nine specific Stormwater Performance Standards, which are to be met to achieve compliance. The Policy presented

in two volumes: Volume One, the Stormwater Policy Handbook, which contains a description of the policy, its implementation,

and descriptions of the nine individual stormwater management standards, and Volume Two, the Stormwater Technical

Handbook, which contains more detailed information on Best Management Practices (BMPs), for stormwater management

(i.e., detention basins, swales, etc.).

The policy is the result of three years of work by a Stormwater Advisory Committee that included representatives from

regulatory offices (EPA, Department of Fisheries and Wildlife, Natural Resources Conservation Service, etc.), engineers and

developers from the private sector, the highway department, and representatives of local conservation commissions. The Policy

is to be implemented as an amendment to the existing Massachusetts Wetlands Protection Act, which is administered at the

local level by local Conservation Commissions.

The nine performance standards are the key components of the policy. General descriptions of the standards include the

following:

1. No new stormwater conveyances may discharge untreated stormwater directly to, or cause erosion in wetlands or

waters of the Commonwealth.

2. Post-development peak discharge rates may not exceed pre-development rates.

3. Maximize recharge to groundwater: post-development must be similar to pre-development conditions.

4. Remove 80% of average annual load-post development of Total Suspended Solids (TSS).

5. Use specific BMPs for discharges from areas with higher potential pollutant loads; untreated infiltration prohibited.

6. Use specific BMPs for discharges to critical areas.

7. Redevelopment projects should not meet performance standards to the maximum extent practicable and at a minimum,

improve existing conditions.

8. Erosion and sedimentation controls are required during construction.

9. Operation and Maintenance Plan for Stormwater Management required.

The Policy was introduced in March of 1996 for testing its effectiveness. Two Phases of training were provided over a twoyear period across the state. The first phase focused on introducing the Policy and the second phase focused on detailed

Engineering Companies, and local DPWs and planning departments.

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In March of 1997, the Massachusetts Department of Environmental Protection (MADEP), in conjunction with the

Massachusetts Office of Coastal Zone Management (CZM), released a draft version of the state’s Stormwater Management

Policy (herein referred to as the “Policy”). Prior to the development of this policy, the control of peak stormwater discharges from

development sites to prevent flooding and erosion problems was a fairly standard requirement across the country; and was

well-implemented in Massachusetts. However, there were no state-level requirements for stormwater quality treatment,

maintaining groundwater recharge processes, or maintaining stormwater treatment systems. The Policy was developed to

provide standard minimum requirements for stormwater management that could be consistently implemented on development

projects.

The Stormwater Management Policy is currently an amendment to the Wetlands Protection Act which is only applicable

when a project proposes work within the boundary, or buffer zone, of a Wetland Resource Area. Hence, the Policy is not

applicable to all developmental projects.

While the regulatory implementation of the Policy is through local Conservation Commissions, under the State’s Wetlands

Protection Act, the performance standards and design guidelines that define the Policy were developed for use by a larger

audience. Development teams (typically the proponent and their engineers, architects, and planners) and the various reviewing

agencies (Conservation Commissions, Planning Boards, DPWs, etc.) were expected to be users of the Policy. The goal was

to provide guidance to ensure that negative impacts from stormwater runoff generated as a result of urban and suburban

development would be minimized without placing an unjustifiable economic burden on developers for new projects, or

preventing redevelopment of existing sites.

The Policy includes nine specific Stormwater Performance Standards for which compliance must be achieved on

development projects. Included in these standards is a requirement to provide groundwater recharge, requirements for ensuring

proper stormwater treatment prior to discharge to waters of the state, and provisions for waiving certain requirements if deemed

infeasible for redevelopment projects. The Policy has been distributed as an Interim Draft to allow for refinements prior to its

final promulgation as state regulations. In orderto fully gage its effectiveness, however, the Interim Policy has been distributed

and implemented as if the regulations were final.

The Policy is presented in two handbooks: Volumes One and Two. Volume One, the Stormwater Policy Handbook,

contains a description of the policy, its implementation, and detailed definitions of the nine individual stormwater management

standards. Volume Two, the Stormwater Technical Handbook, contains detailed information on Best Management Practices

(BMPs), with guidelines for the design of standard stormwater management structures (such as detention basins and water

quality swales).

Development

The Policy is a result of three years of work by a State Stormwater Advisory Committee. In addition to leaders from MADEP

and CZM, this Committee included representatives from such regulatory offices as USEPA, Department of Fisheries and

Wildlife, and the Natural Resources Conservation Service. Also on the committee were engineers and developers from the

private sector (including the author) and representatives from the Massachusetts Highway Department and local Conservation

Commissions.

The goal of the Committee was to provide a cohesive set of performance standards that addressed key issues associated

with stormwater runoff control. The Policy was developed in such a manner that it provides adequate accompanying guidelines

and recommendations, to allow for consistent implementation, while still allowing for flexibility in site-specific designs. Given

the widely varying goals and perspectives of Committee members, the Policy published in 1997 was a result of group

consensus and compromise.

The Committee was divided into two sub-committees, the Policy group, and the Technical sub-committee. The Policy group

was tasked with developing the process for legal implementation and the Technical Committee was responsible for developing

the specific technical requirements of the Stormwater Management Policy.
Some of the performance standards introduced completely new requirements for development projects and required

detailed evaluation and discussion during the development stages. Some of the key issues that generated substantial debate

include the following:

l Recharge:The loss of recharge to groundwater systems, which provide drinking water supplies and generate baseflow

to streams and rivers, was a state-wide problem. A mechanism for requiring the maintenance of recharge after

development was considered a high priority. The biggest issue relative to this requirement was: How much annual

recharge should be required?

l Water Quality Treatment Volume: The quality and quantity of stormwater runoff from paved and unpaved areas can

vary greatly. It was determined by the Committee that runoff from impervious areas was the highest concern and should

require treatment. The largest decision relative to this concern was: What volume of stormwater runoff should be treated

for water quality? Should it include runoff from both pervious and impervious areas?

l Critical Areas: The Committee felt that certain sensitive environmental areas should have the maximum practicable

protection. Under the Massachusetts Stormwater Management Policy, “Critical areas” are defined as; shellfish growing

areas, public swimming beaches, cold water fisheries, recharge areas for public water supplies and designated

Outstanding Resource Waters (ORWs). ORWs are further defined to include surface drinking water supplies, certified

vernal pools, and state designated Areas of Critical Environmental Concern (ACECs). The issue here was how to ensure

that these areas are provided adequate protection and how to define what adequate protection is.

l Exemptions: Some Committee members expressed concern that stormwater management requirements may be too

costly for small residential projects, or may be a deterrent for initiating redevelopment projects. The issue was what, if

any, projects should be exempt from any or all of the standards?

l OperatiortlMaintenance: Maintenance of stormwater management practices is critical for their effectiveness. It is often

difficult, if not impossible, to ensure that the operation and maintenance of BMPs will occur as necessary. The issue was:

How can the necessary maintenance of BMPs implemented on the project be ensured?

A brief summary of the decisions on these key issues is as follows:

l Recharge: Annual recharge processes are permanently changed by the introduction of impervious areas to a site. In

order to minimize this impact, it was agreed that the existing annual recharge should be determined and postdevelopment annual recharge should maintain this to the maximum extent practicable. A preliminary methodology for

determining existing recharge on the site was provided in the Draft Policy.

l Water Quality Treatment Volume:

n For discharges to critical environmental areas (defined in the Policy), the volume of stormwater runoff to be treated

for water quality control is defined as 1 .O inch of runoff times the total impervious area of the post-development project

site.

n For all other discharges, the volume to be treated is calculated as 0.5 inches of runoff times the total impervious area

of the post-development project site.

These volumes represent total runoff from the smaller, more frequent storms that occur annually, and the initial

volumes of runoff from larger more infrequent storm events. The goal behind this decision was to fully treat the runoff

from the majority of the storm events occurring annually, without approaching values where treatment system sizes

would result in increasing costs with decreasing additional benefit.

n Critical Areas: It was decided, as stated above, that 1 .O inch of runoff (as opposed to 0.5 inch) must be treated for

water quality if the discharge is to a Critical Resource Area. Also, specific approved BMPs are recommended for use

in particular critical areas. In addition, it was decided that spill prevention/containment methods must be included in

the Stormwater Management System design.

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l Exemptions: Specific cases were provided exemption from the Policy, including: single family house projects,

residential subdivisions with four or fewer lots that do not discharge to critical areas, and emergency repairs to

highway/roadways or their drainage systems. However, none of these projects are exempt from the standard requiring

sedimentation and erosion control requirements during construction activities.

While redevelopment projects are not exempt, a redevelopment project may comply to the maximum extent possible

if it can be proven that it is not practicable for the project to achieve full compliance.

l Operation/Maintenance: All non-exempt projects require the development of a Stormwater Management System

Operation and Maintenance Plan (O&M Plan). As defined in the Policy, the O&M Plan must contain the: names of the

Stormwater Management System(s) owner and the person(s) responsible for implementing the O&M Plan, a schedule

for inspection and maintenance, and a description of maintenance activities to be performed. Recommendations for

specific maintenance practices and schedules are included in the Policy.

Stormwater Performance Standards

The nine Stormwater Performance Standards most accurately describe the key components of the policy that came out

of the committee deliberations following resolution of the issues described above. The goal of the standards is to protect

groundwater, surface water, and wetland resources from the impacts of stormwater runoff generated as a result of development

and redevelopment projects. General descriptions of the standards are provided as follows:

1. No new stormwater conveyances may discharge untreated stormwater directly to, or cause erosion in wetlands or

waters of the Commonwealth.

2. Post-development peak discharge rates must not exceed predevelopment conditions for the 2-year and 1 O-year storm

events under all conditions. The loo-year event must be analyzed to determine impacts and must be controlled if

necessary.

3. Loss of annual recharge to groundwater should be minimized through the use of infiltration measures, to the maximum

extent practicable. The recharge “requirement” which is to mimic existing annual recharge on sites to the maximum

extent practical, has not been changed. However, a design methodology for estimating existing annual recharge at a

site, and for designing recharge systems has been developed. The methodology uses soil classifications, soil gradation

analyses and specific Massachusetts regional rainfall data as data inputs.

4. Stormwater management systems must be designed to remove 80% of the average annual (post development) load

of total suspended solids (TSS). It is presumed that this standard is met when; (a) suitable nonstructural practices for

source control and pollution prevention are implemented; (b) stormwater management BMPs are sized to capture the

prescribed runoff volume; and (c) stormwater management BMPs are maintained and designed as specified in Volume

Two. The Policy provides estimates of the percent TSS removal for individual BMPs when designed in accordance with

the specified guidelines. Water quality treatment volume is 0.5 inches of runoff from impervious areas (1 .O inch if

discharge is to critical environmental area).

5. Stormwater discharges from areas that are defined as having “higher potential pollutant loads” (as defined in the Policy)

require specific stormwater BMPs. Infiltration of stormwater from these areas without pretreatment is prohibited.

6. Specific BMPs must be used for discharges to critical areas and the water quality treatment volume is 1 .O inch of runoff.

7. Redevelopment projects must meet the performance standards to the maximum extent practicable. It must be clearly

stated why full compliance cannot be achieved and such projects must, at a minimum, improve existing conditions.

8. Erosion and sedimentation controls are required during construction.

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9. An Operation and Maintenance Plan (O&M Plan) for Stormwater Management is required.

A detailed explanation of each of these Standards is available in Volume One, the Stormwater Policy Handbook.

Implementation

In order to test its effectiveness and identify potential problems, the Policy was introduced in March of 1997, prior to the

promulgation of regulations. Copies of Volumes One and Two were distributed to each Conservation Commission office in the

state, and to other relevant regulatory agencies. Two phases of training were provided across the state over a two-year period:

first to introduce the Policy, and then to focus on detailed case studies and implementation issues. Training was made available

to regulatory agencies, Conservation Commissions, local DPWs, planning departments, and engineering companies. During

the training sessions, the largest turnout was from Conservation Commission representatives and engineering/consulting firms,

with minimal attendance by the other groups invited.

At each of the training sessions, questions from the audience on the Policy were solicited and a list of most Frequently

Asked Questions (FAQs) was developed. The FAQs provided an excellent basis for outlining where additional information

and/or clarification was needed. Based on the number of recurring questions, the Committee decided to prepare a survey to

solicit feedback from potential policy users. The survey was comprised of 23 questions for characterizing the respondent,

determining the usefulness and ease of implementation of the Policy, identifying particular problems in understanding or

implementing performance standards, and determining what type of BMPs were currently being implemented.

The survey was not designed to be a statistically valid data set, but rather to gain a practical working knowledge of what

aspects of the Policy and/or its method of implementation needed to be refined. While this was generally evident from the

FAQs, the survey further substantiated the specific areas where additional work was necessary. Some key findings from the

118 respondents to the survey were as follows:

l The overall sense of the Stormwater Performance Standards was that the Stormwater Policy implementation was good

(63%) and that they consider the Stormwater Handbook to be a “useful resource for designing and reviewing systems

(77%).

l In response to the standards, respondents were generally comfortable implementing peak discharge controls and

sedimentation and erosion controls. This was not surprising since these were existing requirements in most

municipalities that needed to be achieved for most development projects.

l Not surprisingly, new requirements for groundwater discharge, treatment of stormwater runoff water, and the

preparation of stormwater Management O&M Plans were the standards for which additional clarification and technical

support were most requested.

Feedback

The Draft Policy was issued prior to formal promulgation so that one to two years of interim implementation could be used

for refinement. The FAQs, user survey, and ongoing feedback from the public defined those areas where refinements were

especially necessary, including the following:

Standard No. 3 Recharge: The recharge requirement clearly created the most confusion, and required additional

technical support. The original brief description included in Volume One was not suff icient for engineers or reviewers to prepare

a comprehensive program for achieving the annual recharge requirement.

As a result, the technical sub-committee has focused on providing a more detailed definition of the recharge requirement

and appointed a group to develop a design methodology for achieving compliance with this standard. The group has developed

a methodology using soil groups and soils analysis and actual rainfall data to determine the existing annual recharge on project

sites. Methodology for designing a recharge system to provide post-development recharge that best mimics pre-development

336
conditions is being developed. This technical is currently in the final stages of development and is expected to be completed

and distributed prior to December 1999.

Standard 4 - 80% TSS Removal: The Total Suspended Solids (TSS) removal requirement was not developed with the

goal of removing only the TSS loads in stormwater runoff. Rather, it was considered an indicator parameter, whereby if 80%

of the TSS is removed, a large portion of the additional pollutants carried in stormwater is also removed. This relationship does

not hold true, however, if the proponent chooses to use only mechanical methods where settling of fines, assimilation of

nutrients, or other biological processes that increase pollutant removal do not occur. For instance, a vegetated infiltrating swale,

or wet pond, that is designed to provide substantial stormwatervelocity reductions may greatly increase fine sediment removal

and may also provide nutrient uptake in addition to gross TSS removal. Astructure that removes solids only, and does not allow

for detention or contact with plants or potential filtering areas does not comply with the goal/intent of the TSS removal standard.

In addition, users were having difficulty calculating TSS removals when numerous BMPs were to be used in a series. The

specific percent removal rates provided in Volume One of the Policy are not additive and, as such, must be calculated as

percents of the pollutant load that they receive.

In response to these issues, further definition of the goal of the TSS removal requirement and recommended practices for

achieving the goal are being developed. A spreadsheet has been developed, which can be easily filled out by hand, to assist

in calculating the percent TSS removal for a project based on the BMPs implemented.

Standard 9 - Operation and Maintenance: This standard has consistently raised the most concern relative to cost and

implementation. Common questions were as follows:

l Who will pay for ongoing operation and maintenance of stormwater BMPs if it is not the town?

l How will the town fund the O&M requirements if they assume responsibility?

. What long-term mechanism is there to ensure that maintenance will be completed?

l What is the frequency of maintenance required for specific BMPs?

While these questions are difficult to answer, for a specific site or on a statewide basis, in terms of required maintenance,

the Committee has responded by preparing operation and maintenance checklists, which may be used by the operator/owner.

These checklists may be submitted to the local Conservation Commissions on an annual basis, if deemed necessary.

Specific maintenance practices and suggested frequencies have also been prepared and are currently being updated, as

new information becomes available. It has also been noted that “one size does not fit all” in terms of required maintenance.

For instance, an infrequently used residential guest parking area clearly does not warrant the same frequency of street

sweeping as a commercial mall parking lot.

The question of financing stormwater management system operation and maintenance activities is also a site- and locationspecific issue. The development of stormwater utilities and management districts is ever increasing and may be the option that

some communities choose. The promulgation of the Policy as regulations will require the project proponent and/or towns and

municipalities to develop a plan for ensuring O&M implementation. There are a variety of ways this may be achieved.

Resolution may be somewhat facilitated in larger municipalities and/or USEPA-designated urban areas that must comply with

the upcoming final USEPA NPDES Phase II Stormwater Regulations.

Summary

The development of the Massachusetts Stormwater Policy, which includes nine performance standards, was an integrated

effort between state and local regulators, policy makers, engineers, developers, and the general public. The group effort and

the implementation of the Policy as a Draft, to which refinements could and have been made, have contributed to the

usefulness of the standards. While the development and implementation of the standards are still in the early stages, the Policy

provides definitive goals for achieving stormwater water quality and quantity control, and addresses annual recharge on

337
development sites. Until the development of these standards, there was no requirement to maximize groundwater recharge

on sites or to mandate the development of the stormwater O&M Plan (unless required under other regulatory programs). These

advances will provide an overall benefit to the natural resources of the Commonwealth of Massachusetts. The Stormwater

Management Policy Volumes I and II may be obtained off the Internet or by request from:

Tom Maguire

Massachusetts Department of Environmental Protection

1 Winter Street

Boston, MA 02108

Phone (617) 292-5602

email: Tom.maguire@state.ma.us

References

Massachusetts Coastal Zone Management, Massachusetts Department of Environmental Protection, Stormwater Management

Volume One: Stormwater Policy Handbook, March 1997.

Massachusetts Coastal Zone Management, Massachusetts Department of Environmental Protection, Storrnwater Management

Volume Two: Stormwater Technical Handbook, March 1997.

Massachusetts Coastal Zone Management, Massachusetts Department of Environmental Protection, The Stormwafer

Evaluation Survey: Perspectives on the implementation of the Interim Massachusetts Stormwater Policy, June 1988.

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Implementation of Michigan’s Voluntary

Stormwater Permit-a Community Perspective

Kelly A. Cave, P.E. Director

Watershed Management Division

Wayne County Department of Environment

Detroit, Ml

Dale S. Bryson

Camp Dresser & McKee

Detroit, Ml

Kelly C. Kelly, P.E., Project Engineer

Canton Township, Ml

Jack D. Bails, Vice-President

Public Sector Consultants

Lansing, Ml

Introduction

The Rouge River National Wet Weather Demonstration Project (Rouge Project) has made significant progress in

restoring beneficial uses to a large, urban waterway using a holistic, “bottom up” watershed approach. This project was

initiated in 1992, by the Wayne County (Michigan) Department of the Environment. The purpose of this document is to

present a summary of the activities and progress of the Rouge Project; discuss the watershed approach being utilized in

the Rouge Project, including the use of a general storm water permit; and summarize a community perspective on this

entire effort.

Rouge Project Background and Summary of Progress to Date

The Rouge River National Wet Weather Demonstration Project is a watershed-based effort, substantially sponsored

by the U.S. Environmental Protection Agency (USEPA), to manage wet weather pollution to the Rouge River, a tributary

to the Detroit River in southeast Michigan (See Figure 1). The Rouge River Watershed is largely urbanized, spans

approximately 438 square miles, and is home to over 1.5 million people in 48 communities in 3 counties. The Rouge River

has been designated by the international Joint Commission as a significant source of pollution to the Great Lakes system.

The early focus of the Rouge Project was the control of CSOs in the older urban core portion of the downstream areas

of the watershed. As a finite number of point source CSO discharges could be identified, and responsibility for each

defined, the traditional regulatory approach of issuing National Pollutant Discharge Elimination System (NPDES) permits

mandating corrective action worked relatively well. Additional monitoring of the river showed, however, that other sources

of pollution needed to be controlled before full restoration of the river would be achieved throughout the watershed. These

other sources of pollution include storm water runoff, interflow from abandoned dumps, discharges from illicit connections,

discharges from failed on-site septic systems, and resuspension of contaminated sediment.

The Rouge Project is designed to identify the most efficient and cost-effective controls of wet weather pollution, while

assuring maximum use of watershed resources. A great deal has been accomplished in these efforts. The following

summarizes some of those accomplishments, focusing on CSO controls first. Approximately 50% of the watershed is

served by separate sewer systems, with an additional 20% served by combined sewers (157 overflow points), and the

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Figure 1. Rouge Subwatersheds & Location of Rouge Watershed in Michigan.

remaining area served by on-site sewage disposal systems. CSO controls are being implemented in phases. Under the

first phase, six communities have separated their sewers and eight communities have constructed or are constructing 10

retention treatment basins. Each of these basins is sized for different design storms and several employ innovative

technologies. A two-year evaluation study of the CSO control basins began on June 1, 1997. The results from the

evaluation study, coupled with efforts to control storm water and other pollution sources in the watershed, will provide the

basis for the second phase CSO control program for the remaining CSO sources in the watershed. The information gained

from the evaluation of design storms and control technologies will be useful to others nationwide to determine cost-effective

CSO controls to meet water quality standards.

The Rouge Project is also evaluating innovative stormwatercontrol and watershed management technologies. Twentyfive different communities and agencies throughout the watershed are implementing over 100 pilot projects. Categories

of pilot management projects currently underway include wetlands creation and restoration; structural storm water

practices, such as grassed swales and detention ponds; erosion controls; stream bank stabilization; and habitat restoration,

to name a few.

The Rouge Project also discovered that illicit connections and failing septic systems are major sources of pollution

problems in the Detroit urban area. Creative ways to remediate these sources of pollution have been initiated.

A suite of computer models has been developed by the Rouge Project. These models simulate the water quality and

quantity response of the Rouge River during wet weather events for existing and future conditions, and under various CSO

and stormwater runoff management alternatives. This effort has resulted in a very useful public communication tool on

water quality indices tied to actions needed to restore the Rouge River. A comprehensive geographic information system

(GIS) and relational databases were designed and implemented to manage the wealth of data collected under the Project.

In addition, a special data exploration tool, DataView, was developed to support routine analyses of large time-series data

sets. DataView is user-friendly and readily transferable to other locations. Related to DataView is the Rouge Information

Manager, also a user-friendly, readily transferable tool (an “electronic file cabinet”) for accessing multi-media information

about the Rouge River restoration effort.

Effective, readily transferable tools have been developed, employed by the Project, and are being shared with other

cities and state agencies. Additional information on the Rouge Project can be obtained from the web site at

h ttp:\www. rougeriver. corn.

Evolution of the Watershed Approach

The Rouge River watershed has seven subwatersheds that range in size between 19 and 89 square miles (See Figure

1). Older communities served by combined sewers dominate downstream portions of the Rouge River Watershed, while

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the headwater areas are typically open space, agricultural land, or low density residential developments that are

undergoing rapid change due to growth pressures. Fully developed areas, typical of the middle portions of the Rouge

Watershed, have separated storm sewers and limited opportunities to address stormwater problems with structural

solutions.

Data gathered by the Rouge Project have shown numerous water quality and designated use problems, including high

bacteria levels and low dissolved oxygen levels during wet weather events in all areas of the watershed. Fish consumption

is prohibited in much of the watershed due to the threat to human health. Six of the seven subwatersheds have moderate

to severe degradation of wildlife habitats, with fish populations suffering severe impairment in three of the subwatersheds.

Aesthetic enjoyment is moderately to severely impaired throughout the watershed. Restrictions to small boat navigation

resulting from logjams, garbage and sedimentation are a moderate to severe impairment in virtually all seven

subwatersheds.

Based upon what was learned, the focus of the Rouge Project became more holistic to consider impacts from all

sources of pollution and use impairments in receiving waters. The historic implementation of water quality management

programs in the United States at the federal and state levels has been to focus on point sources, which are the most

obvious sources of pollution to water bodies. This approach has worked well to control pollution from most point sources

but has also left a patchwork of regulated and unregulated discharges of stormwater and nonpoint source pollution to

surface waters. This patchwork is especially evident in most urbanized areas where multiple local jurisdictions are located

in the same watershed. More subtle sources of pollution, such as stormwater, have emerged as the next priority for

attention. The challenge for the Rouge Project became to develop innovative, coordinated solutions to achieve water

quality objectives that may be: (1) be more cost-effective, (2) implemented in a more timely fashion, and (3) better able

meet local needs.

It has become clear that water resources management must have the support of the general public in order to be

effective and to become self-sustaining. A locally driven watershed approach to pollution management as a means to

achieve management goals is an exciting concept discussed by many, but for which there is limited practical experience.

This is particularly true in urban situations where there are multiple sources of impairment to a water body and stiff

competition for limited local resources to address the pollution sources. The Rouge Project has provided a unique

opportunity for a watershed-wide approach to restoring and protecting an urban river system by using a cooperative, locally

based approach to pollution control.

The Michigan NPDES General Permit for Municipal Stormwater Discharges

As concern expanded to sources of pollution in the upper portion of the watershed above the CSO discharges, and

water quality improvement focused more on watershed-wide approaches, the lack of a defined regulatory framework to

address stormwater pollution and diffuse nonpoint source pollution became a major obstacle to further progress in

improving water quality and restoring beneficial uses to the Rouge River. Beginning in 1995, the Michigan Department of

Environmental Quality (MDEQ), the Rouge Project, and the communities in the Rouge Watershed jointly developed an

innovative, watershed-based NPDES general permit (“General Permit”) for municipal stormwater discharges. The permit

was issued on July 31, 1997 (MDEQ, 1997). This collaborative process was outlined in a report entitiled “Adapting

Regulatory Frameworks to Accommodating Watershed Approaches to Storm Water Management” (Fredericks, et al.,

1997).

The MDEQ General Permit and USEPA’s draft Phase II stormwater regulations (U.S. Environmental Protection

Agency, 1998) due to be promulgated in September 1999, were developed during the same time frame. Wayne County,

on behalf of the Rouge Project communities, was selected to serve on USEPA’s Urban Wet Weather Flows Federal

Advisory Committee, which (among other activities) assisted USEPA with the development of the Draft Phase II

Stormwater Regulations. Participation on the federal advisory group on watershed approaches to stormwater management

was invaluable to the development of the Michigan General Permit, and provides a high likelihood that the General Permit

will be acceptable for implementing the forthcoming federal Phase II Stormwater Regulations in Michigan.

The General Permit incorporates the following elements:

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General:

- Permit coverage is voluntary until the final EPA Phase II Stormwater Regulations are promulgated

- Public agencies who own, operate, or control stormwater systems are provided the opportunity for coverage

- Watershed size is established by the potential permitees during the application process

- Application and permit process have limited required actions; the focus is to establish desired outcomes.

Requires permittee to develop the followinq:

- lllicil Discharge Elimination Plan (IDEP) that has the goal of eliminating raw sewage discharges and includes

addressing failing septic systems and improper connections of sanitary sewers to storm drains and open waterways.

- Public Education P/an (PEP) designed to inform residents and businesses about what actions they should take to

protect the river.

- In cooperation with others, a Watershed Management P/an to resolve water quality concerns which includes: short

and long-term goals for the watershed, delineation of actions needed to achieve the goals, estimated benefits and

costs of management options, an opportunity for all stakeholders to participate in the process.

- Storm Water Pollution Prevention Initiative, which includes evaluation and implementation of pollution prevention

and good housekeeping practices and the evaluation and implementation of BMPs to minimize impacts of new

development and redevelopment.

- Monitoring and Reporting P/an, which includes a schedule for revisions to the Watershed Management Plan.

The IDEP and PEP are submitted to MDEQ at the time of application and the implementation of these plans begins

when the MDEQ issues a certificate of coverage to a community/agency. Within six months after the issuance of a

certificate of coverage to a community/agency, the General Permit requires the submission of a public involvement plan

for approval by the state. This plan identifies the approaches that will be used within the hydrologic area to involve

stakeholders in the development of a watershed plan that must be completed within 18 months after the certificate of

coverage is issued. Once a consensus, long-term management plan has been completed, each agency and community

within the watershed must prepare and submit for state approval its own pollution prevention initiative that identifies actions

and schedules to address the pollution concerns identified in the consensus watershed plan. The watershed stormwater

management plans developed by the communities and other public agencies do not require state approval; however, the

individual pollution prevention initiatives emanating from the watershed planning process do require state approval, as the

activities specified in the initiatives become permit requirements upon approval.

Rouge Community/Agencies Approach to Application and Permit Requirements

A total of 43 communities and agencies who own, operate, or control stormwater systems in the Rouge River

Watershed have obtained coverage under Michigan’s new watershed-based General Permit for municipal stormwater

discharges. The result is that over 95% of the watershed is covered under this new program. The communities and

agencies requested that, for purposes of the General Permit, the large Rouge watershed be subdivided into the seven

subwatersheds shown in Figure 1. Long-term management plans will, therefore, be developed for each of these

subwatersheds, with coordination of the plans provided by the MDEQ and the Rouge Project staff. The document

“Implementing a Model Watershed Approach Through a State General Storm Water NPDES Permit” (Cave, et al., 1998)

outlines key issues discussed and decisions reached by the communities as they developed their General Permit

applications during 1998. The following section presents additional information regarding the application and permit

requirements recently approved for the communities and agencies in the Rouge Watershed under the Michigan General

Permit.

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The Michigan General Permit for municipal stormwater discharges is quite flexible and allows those seeking coverage

under the permit to use a wide variety of approaches to meet the public education, illicit connection/illegal discharge, and

public involvement requirements. This flexible framework has allowed communities to experiment with various approaches

that recognize local constraints and seize upon unique opportunities to meet the desired outcomes. While the basic

requirements for what must be in the watershed plan are more detailed, the permitees within a watershed are allowed

considerable freedom in deciding upon their own priorities, remedial actions, and schedules. Pollution prevention initiatives

that are expected to be proposed by the communities will likely involve commitments to continue or expand current

activities, like soil erosion and sedimentation control; implementation of new activities to address priority issues such as

failing septic systems; and implementation of regional projects to reduce the frequency and velocity of storm flows in the

river.

Table 1 and Table 2 outline the variety of public education and illicit discharge detection and elimination approaches

identified by the communities and public agencies in the Rouge Lower 1 Subwatershed (Figure 1).

Across the watershed, communities actively sought ways to cooperatively address illicit connection/illegal discharge

investigations and public education projects. In one subwatershed group, a community with experience in the production

of videos agreed to make a river stewardship video that all other communities within the subwatershed could use on cable

television, or through the distribution of cassette copies to local libraries and/or schools. In the same watershed, another

community offered the use of a consultant to solicit bids for freestanding public information display boards and to develop

stormwater information materials for the boards that could be used by all communities at public gatherings and inside

public facilities. One community obtained the support of the local college to house and provide administrative support for

a well-established non-profit organization, the Friends of the Rouge organization, whose public information activities were

subsequently funded by several subwatershed groups to implement portions of their public education plans.

Advantages of Watershed Approach

The following section presents some of the lessons learned as the communities and agencies in the Rouge Watershed

are beginning to implement the watershed-based, Michigan General Permit for municipal stormwater discharges.

Holistic Solutions/Local Ownership. There are distinct advantages in managing stormwater on a watershed basis. From

the work already completed on the Rouge Project, it is clear that an integrated approach is needed to address all sources

of water pollution and excessive flows in this urbanized watershed. By requiring those agencies and communities with

responsibility for stormwater to work together at the subwatershed level to establish goals and objectives, local agencies

and the state regulatory agency are forced to view solutions holistically. To achieve the desired level of river restoration,

there must be integrated action plans that address not only stormwater but failing on-site sewage disposal systems

(OSDS), CSOs, sanitary sewer overflows (SSOs), and significant nonpoint sources of pollution.

Ideally, a watershed-based regulatory framework should encompass all dischargers so that pollution sources can be

addressed holistically. Practically, it must be recognized that prior NPDES permit programs at the state and federal level

are already in place for municipal and industrial point source waste treatment discharges, and for many industrial and

commercial stormwater discharges. While the Michigan watershed-based stormwater General Permit covers only public

agencies that own, operate, or control stormwater conveyance systems not currently under a Phase I Stormwater Permit,

the required watershed management plan does provide aframeworkfor integrating activities under other permit programs.

In addition, the General Permit gives communities and agencies the flexibility and encouragement to incorporate nonpoint

source controls and pollution prevention activities as part of the required watershed management plan. For example, many

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Table 1. Illicit Discharge Elimination Activities to be Implemented under Michigan Stormwater General Permit in Communities in Lower 1 Subwatershed,

Rouge River Watershed

et-ate with county for implementing an OSD

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Table 2. Public Education Activities to be Implemented Under Michigan Stormwater General Permit by Communities in Lower 1 Subwatershed, Rouge

River Watershed

X

X

iiE!EE X X X

X X X

X X X

communities have initiated pilot projects to evaluate how stormwater best management practices (BMPs) will control

stormwaterflow and prevent pollution. In some cases, these pilot projects have permanently changed the way communities

and/or government agencies manage stormwater. These management practices will be included, as part of a watershed

management plan, and credit will be given to the entities that are performing those functions.

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Many of the subwatershed units selected in the Rouge River Watershed involve communities that have combined

sewers, separated sewers, and OSDS. Some individual communities have all three within their corporate limits. Once the

communities began to work together at the subwatershed level to establish goals to achieve water quality standards

necessary to restore the river, each found that they had a significant role in the process and that the control of flow in the

rapidly developing headwater areas was as significant as CSO problems in the lower portion of the watershed. Evaluating

the sources of water quality problems and/or the threats to existing uses of the river at the subwatershed level by local

agencies is leading to a better understanding of local constraints, opportunities for innovative solutions, ownership of the

long-term river restoration effort, and interagency cooperation.

Overcominq InstitutionaVRequlatorv Barriers. Local agencies and communities in urbanized areas have a long history

of cooperative efforts to address the delivery of common public services. Recent trends in Michigan, and elsewhere in the

country, to reduce the size and cost of government and limit local taxing power have accelerated efforts at the local level

to integrate or share the cost of a broad range of government services. Local agencies are increasingly seeking ways with

their neighboring jurisdictions to reduce the cost of police and fire protection, solid waste disposal, libraries, recreational

facilities, infrastructure maintenance and repairs, public transit, water supplies, and sewage disposal. Unfortunately, except

in a few isolated instances where a single authority has been created to oversee all aspects of water management, the

legal responsibility for stormwater is widely dispersed among local communities, county health and drain agencies, road

agencies, private developers, and autonomous school districts and public colleges. The creation of a new level of

government in the form of a water management authority with broad powers has been resoundingly rejected in the Rouge

River watershed by local agencies and is likely to receive the same reception in many other urban areas of the country.

State and federal water quality regulatory programs have traditionally focused on large point sources where

responsibility for obtaining and complying with specific permit limits is easy to establish. The regulatory framework to

control water pollution has generally discouraged rather than encouraged cooperative solutions among communities and

has relied upon command and control to achieve results. The complexities involved in addressing wet weather pollution

problems in urban areas, and the widely dispersed accountabi!ity for managing stormwater, demands a new regulatory

framework that will encourage cooperation among the locally responsible public agencies to design integrated, holistic

solutions. The watershed approach to stormwater regulation developed in Michigan offers an opportunity to overcome the

institutional and regulatory impediments that have discouraged cooperative local approaches to restoring urban

watersheds.

Institutional arrangements and financing options necessary to implement the General Permit and subwatershed

management plans are among the many elements the local communities in the Rouge Watershed are addressing in their

working groups. As part of the subwatershed planning process, communities and agencies are also identifying issues

which cross subwatershed boundaries. Rouge Project staff and the MDEQ currently provide coordination of individual

subwatershed efforts and assist subwatersheds in developing a comprehensive strategy for addressing watershed-wide

issues. The subwatershed communities are also identifying those activities, such as public education and water quality

monitoring, that may be most cost-effectively performed throughout the entire watershed by a single entity.

Increased Local Accountabilitv and Political Supuort. Building a watershed restoration project from the bottom-up by

helping local communities and agencies identify problems, set their own priorities for restoration, select their own remedial

measures and propose their own schedules requires a sharing of power among federal, state, and local agencies not

usually found in water pollution control programs. The General Storm Water Permit program in Michigan is voluntary at

this time and it has allowed state regulators the ability to provide flexibility that might not otherwise be available. It has also

increased the accountability of local agencies who no longer have the freedom to blame federal and state officials for the

impositions of requirements, but now are responsible for convincing local elected officials that the programs proposed are

in the best long-term interest of the local residents.

Opportunities for Cost Eff iciencies/lnnovation. As discussed earlier, the Rouge River communities that have obtained

coverage under Michigan’s General Storm Water Permit and are working in subwatershed groups have already developed

more cost effective and efficient methods to meet public education requirements through cooperatively developed projects.

Similar joint programs are underway to train local community and agency staff in illicit discharge elimination activities and

in sharing staff and equipment to conduct river and enclosed storm drain surveys. The three county health agencies are

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developing common approaches to permitting and inspecting OSDS. The county road agencies are working with the state

highway agency to address the design, construction, and maintenance of transportation drainage systems.

The county agencies in the three counties responsible for designated storm drains are working together and with local

communities toward implementing common standards for stormwater management at new developments. County and local

officials have worked together to establish protocols for rapidly developing independent GIS to assure that databases can

be integrated to assist in watershed-wide water quality/quantity management. The economic and political cost for each

community or county agency to develop these approaches has been an impediment in the past. The watershed approach

has enabled these cooperative programs to be established. It is anticipated that the pollution prevention initiatives required

following completion of the watershed management plans would also involve joint projects.

Establishing a broad range of cooperative programs to address stormwater problems across jurisdictional boundaries

is, in of itself, innovative. However, with the development of comprehensive watershed plans, new practical approaches

to implementing total maximum daily load (TMDL) requirements of the Clean Water Act and effectively using water pollution

trading options created at the state level become possible. The Rouge River National Wet Weather Demonstration Project

is funding a pilot program to verify that the watershed management framework under the Michigan Stormwater General

Permit can be used to meet the TMDL requirements, ahead of state schedules (and at potentially lower cost), and the

objectives of the Clean Water Action Plan program. In addition, the pilot program will demonstrate how the General Permit

watershed framework can be used as a basis for the proposed statewide water quality trading program currently under

development.

The top-down, command-and-control approach often requires repeated threats or legal action by state and federal

regulators to ensure compliance with requirements due to lack of political will at the local level. Locally generated

watershed plans containing specific action schedules that have been adopted by elected boards, commissions, and

councils are less likely to be abandoned or require enforcement actions to assure compliance. Peer pressure and citizen

support at the local level should be sufficient incentive in most instances for each local agency to complete their

responsibilities on schedule. Where legal enforcement action is required, the state and federal agencies are more likely

to find support among other local agencies who have met their obligations as outlined in the joint subwatershed plan.

Conclusions and Recommendations from a Community Perspective

Local communities in southeast Michigan and the state regulatory agency are attempting, for the first time, a

consensus, cooperative approach to stormwater management and regulation under the NPDES program. The Michigan

General Permit is a watershed-based, general stormwater permit issued under the National Pollutant Discharge Elimination

System. The permit requires permitees to immediately initiate activities, such as illicit discharge elimination, and to

participate in watershed management planning for a self-determined hydrologic unit. The watershed management plan

forms the basis for implementing watershed goals and objectives, including improved water quality and pollution control.

This new regulatory program implements the watershed approach endorsed by USEPA and others and should facilitate

watershed-based integration of control programs for different pollution sources, such as stormwater CSOs which may be

present within a large, urban watershed. In addition, it is believed that the new watershed-based stormwater program in

Michigan will achieve the objectives of the TMDL program, the Clean Water Action Plan Program, and water quality trading

programs under development across the country. From the perspective of local communities and agencies, this approach

provides optimum flexibility to solve the most pressing problems in their subwatersheds by empowering them to identify

problems, choose from alternative solutions, establish priorities and schedules, and develop common strategies with

neighbors. Communities and others involved in this new program are also addressing issues such as coordination of

subwatershed efforts within larger watersheds.

The Rouge Project (and others) have shown that by holistically addressing all sources of pollution, a cost-effective

action plan can be implemented to address impairments and restore river uses. Storm water issues cannot be corrected

in a vacuum, but must be integrated into an overall solution that addresses the physical, chemical, and biological stressors

in a waterway. Stormwater adversely affects all three and, therefore, must be woven into the fabric of the overall watershed

management plan and watershed control program. Without this integration, stormwater control will become another “add

on” program that misses an opportunity to encourage an integrated program that addresses all sources of ecosystem

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stress in a cost-effective, prioritized manner. The approach being followed in the Rouge River Watershed should prevent

misplaced efforts and, most importantly, result in a restored Rouge River on a much faster timetable.

A key objective of the Rouge River National Wet Weather Demonstration Project has been to demonstrate alternative

methods to a “command and control,” top down regulatory approach for water quality protection and improvement. The

alternative methods sought by the Rouge Project leverage “bottom-up” approaches that put place-based needs in the

forefront and use local initiatives to make progress on water quality restoration. This approach has led to a number of

institutional changes in the watershed that will help sustain the watershed management efforts into the future. From the

perspective of the communities involved, the cooperative, iterative approach being followed appears to be working and

is a welcome change from traditional “command and control” relationships with regulatory agencies.

The Rouge Project approach demonstrates that watersheds can be “managed.” When water quality objectives can

only be reached through control of CSO, stormwater, and nonpoint sources, watershed management must involve the

active participation of local units of government. From a community perspective, this local involvement is critical to the

overall success of the Project and to stream restoration. Also, from a community perspective, undertaking a watershed

effort is not a simple matter. Watershed planning and implementation takes a large commitment of time and effort.

The communities involved in the Rouge Project have a sense of overwhelming success with the watershed restoration

efforts to date. Water quality and ecosystem health are improving, and the demonstration techniques have resulted not

only in concrete and steel structures, but in real institutional changes that integrate the work of stormwater and watershed

improvement into the basic institutions of government. Most importantly, the public is able to utilize new canoeing areas

and other river-based amenities, which are now possible due the noticeable improvement in water quality, aesthetics, and

other attributes of the river. It is hoped that this effort, and the work of the Rouge River National Wet Weather

Demonstration Project, will continue to identify and quantify the benefits of cooperative, watershed-based efforts to protect

and restore our nations water resources.

Acknowledgments

This paper represents a summary of select elements from the ongoing efforts of many individuals and organizations

involved in the restoration of the Rouge River in southeast Michigan. The authors also gratefully acknowledge the

assistance of Ms. Sandra Kiser during the preparation of this manuscript.

The Rouge River National Wet Weather Demonstration Project is funded, in part, by the United States Environmental

Protection Agency Grant #X995743-01 through 04 and #C995743-01. The views expressed by individual authors are their

own and do not necessarily reflect those of USEPA. Mention of trade names, products, or services does not convey, and

should not be interpreted as conveying, official EPA approval, endorsement, or recommendation.

References

Cave, K. and J. Bails (1998). “Implementing a Model Watershed Approach Through a State General Storm Water NPDES

Permit”. Proceedings of WEFTEC 98.

Fredericks, R., K. Cave, and J. Bails (1997). “Adapting Regulatory Frameworks to Accommodating Watershed Approaches

to Storm Water Management.” Proceedings of WEFTEC 97.

Michigan Department of Environmental Quality (July 30,1997), National Pollutant Discharge Elimination System, General

Wastewater Discharge Permit, Storm Water Discharges from Separate Storm Water Drainage Systems, Permit No.

MIG610000.

U.S. Environmental Protection Agency (January 9,1998). “Draft Phase II Federal Storm Water Regulations.“40 CFR Part

122 & 123.

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California’s Model Urban Runoff Program (MURP):

Urban Runoff Programs for Small Municipalities

Jennifer Hays, Assistant Engineer

Public Works Department

City of Monterey, California

Cy Oggins, Coastal Program Analyst III

California Coastal Commission

Central Coast District

Santa Cruz, California

Background

Monterey Bay is a crown jewel of the California Coastline and has received special protection under the National

Marine Sanctuaries Act since September 1992, and the California Coastal Act since 1976. The 5,300 square mile Monterey

Bay National Marine Sanctuary includes a number of small coastal communities, and ranges from the City and County of

San Francisco on the north to Cambria on the south. The cities of Monterey and Santa Cruz have long recognized that

protection of the unique marine resources within the Sanctuary is critical to the economic vitality and quality of life of their

communities. Monterey Bay, with its world renowned Monterey Bay Aquarium, rich bird and marine resources, recreational

opportunities that include the Santa Cruz Boardwalk, and commanding vistas has become a major tourist attraction.

The Cities of Monterey and Santa Cruz developed and implemented a Model Urban Runoff Program (MURP) in a

cooperative team effort with the Monterey Bay National Marine Sanctuary, the California Coastal Commission, California

Regional Water Quality Control Board-Central Coast Region, and the Association of Monterey Bay Area Governments

(AMBAG) funded by an EPA 319(h) grant. The MURP was developed to address and support a number of environmental

regulations and initiatives that applied to the Sanctuary and adjacent coastal areas including: the Sanctuary’s Water Quality

Protection Program, requirements of the Coastal Zone Act Reauthorization Amendment (CZARA), Coastal Commission

plans and policies, the Regional Board’s watershed management initiative and basin plans, the State Water Resources

Control Board’s Ocean Plan and Nonpoint Source Pollution Control Program, and EPA’s proposed draft Storm Water

Phase II Rule (Storm Water Phase II).

The concept of the MURP originated in the Sanctuary’s Water Quality Protection Program for Monterey Bay National

Marine Sanctuary-Action Plan Implementing Solutions to Urban Runoff and a State’s Urban Runoff Technical Advisory

Committee Report, developed to address Section 6217 of CZARA.

One of the most important drivers in the development and implementation of the MURP was an initiative of municipal

leaders to address the value that the community places on protecting the local creeks, streams, and wetlands and the

Sanctuary’s marine biological resources.

Development of Model Urban Runoff Program

A key objective of the MURP was to produce a document that would assist other communities in the development of

their own urban runoff programs by providing an off-the-shelf “how-to” guidebook building on the experience gained

through the development and implementation of Phase I Storm Water Management Programs. A second objective of the

project was the development of Urban Runoff Management Programs forthe cities of Monterey and Santa Cruz that would

address the community’s values and achieve early implementation of and compliance with the various regulatory programs

and initiatives.

Representatives from Phase I municipalities who were responsible for the development of their programs and had

gained experience in implementation were consulted throughout the project. They participated in workshops when the

MURP was presented to Monterey Bay municipalities and provided extensive information and examples of material used

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in their communities, including what worked and what didn’t. Woodward-Clyde Consultants, with its extensive experience

in working with Phase I municipalities, was selected to assist the project team in developing and producing the MURP.

The cities used a conceptual framework for developing urban runoff programs appropriate for their individual needs

following the guidance recommended by the MURP. It included four major steps:

l Assessment - Institutional assessment and assessment of environmental resources and sources of pollutants of

concern

l Development - Program management, institutional arrangements and coordination, legal authority, and fiscal

resources

9 Implementation - BMPs and model programs for each of the six control measures proposed in Storm Water Phase

II and for control of commercial and industrial activities

. Evaluation - Progress reporting and evaluation, water quality monitoring, and program update.

Periodic meetings were held during the two-year grant period to share, review, and comment on individual city work

products, review progress, prepare and validate the MURP, and discuss early implementation actions. The Sanctuary was

instrumental in the early implementation effort by providing public information and outreach support and developing public

education materials. The Coastal Commission played an active role in formulating strategies for addressing Sanctuary-wide

water quality and land use concerns and providing support in the development of GIS-based land use maps. Project status

reports were presented to the Monterey Bay Regional Stormwater Management Task Force, AMBAG, city councils, and

Monterey Bay area public works officers.

The Model Urban Runoff Program

The MURP contains these four major steps for the development and implementation of an urban runoff program, and

a corresponding appendix containing additional information, examples, models, references, and contacts for further

information.

The Assessment Phase of the MURP describes the importance of information gathering and research to provide an

early survey of the municipalities, current policies, programs, legal authorities, and fiscal resources applied to control urban

runoff. A similar institutional assessment of existing regional storm water, watershed, and other water quality control

programs is recommended to avoid duplication and to identify potential conflicts, opportunities for coordination, and areas

not previously addressed. This phase also provides guidance and methods for (1) describing a community’s water

resources and activities that can be impacted by polluted runoff, (2) mapping the storm drainage system, (3) developing

a relationship of pollutant sources/activities to pollutants of concern, and (4) developing a working map to assist in targeting

problem areas or pollutant sources. Coordination with and building upon existing efforts, including joining Phase I

programs, is encouraged.

The Development Phase of the MURP describes the (1) selection of the program management structure, (2) identifies

individual and departmental responsibilities for management of individual program elements (public education, control

measures, or BMPs) and (3) coordination with other internal and external programs and agencies. The legal authority to

ensure implementation of BMPs and achieve compliance with the MEP standard of the Clean Water Act was developed

through use of a model ordinance. The appendices include examples of language for the amendment of Local Coastal and

General Plans as required by the State of California. Revisions to the California Environmental Quality Act checklist were

recommended to provide planners an additional tool to evaluate impacts of runoff from both new development and redevelopment. This Phase includes an estimate of staffing resources to implement each element of an urban runoff

program. It also describes the use of assessment districts, storm water utility fees, and other sources of funding program

implementation.

The Implementation Phase of the MURP describes eight program elements including six required by EPA’s Phase II

draft regulations as minimum requirements MURP program elements include (1) public involvement/participation, (2) a

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public education and outreach program, (3) an illicit connection and discharge detection and elimination program, (4) a

municipal operations control program, (5) a construction site discharge control program, (6) a new

development/redevelopment control program, (7) an optional control program for commercial facilities, and (8) an optional

control program for industrial facilities. The MURP recommends objectives, BMPs, implementation activities, and methods

for program evaluation and documentation. This includes measurable goals for each of the eight program elements. The

appendices contain numerous examples of public participation and education; BMPs for residential areas, food service

operations, municipal operations, construction sites, vehicle service facilities, and shopping centers; sample SWPPPs for

corporation yards and construction sites; and reporting forms.

The Evaluation Phase describes methods for (1) determining whether water quality is improving and whether the

efforts and resources are directed at the right source and pollutants of concern; (2) reporting progress using the BMP

measurable goals, and (3) the developing and implementing of water quality monitoring programs and volunteer monitoring

programs. This phase provides and stresses the need for procedures for modifying and updating the urban runoff program

using the evaluation tools.

Each section of the MURP contains an extensive list of references to assist municipalities in obtaining additional

detailed supporting information on how these programs were developed.

Implementation of the Model Urban Runoff Program

Municipalities in California’s major metropolitan areas were encouraged, and in some cases required, to file for

NPDES’ permit coverage on an area-wide basis. Numerous smaller municipalities are already regulated by Phase I

requirements. There are now approximately 260 municipalities, with a combined population of 29 million, regulated by

Phase I NPDES permits in California.

In California, 76 incorporated places and counties are proposed to be automatically designated and 38 areas outside

urbanized areas that could be potentially designated under Storm Water Phase II. The Monterey Bay Area has 13

incorporated places and counties that would be automatically designated. The MURP will be of significant benefit to a

number of smaller California municipalities, and particularly in the area covered by this project.

Undertaken as part of a 319(h) Grant, this project was required to conduct an outreach effort to ensure early

implementation of urban runoff programs. Two workshops were held in April of 1998 for planning, public works, building,

parks, public information/education, and general municipal operations staff in the Monterey Bay Area. These workshops,

attended by approximately 120 individuals, covered an introduction to urban runoff pollution, and regulatory requirements.

They featured presentations from individuals experienced in the development and implementation of Phase I storm water

management programs and included four break-out workshops covering MURP development and implementation.

The agencies participating in the development of the MURP have undertaken a number of actions, described in the

following paragraphs, to implement the project recommendations.

City of Monterey

During the development of the MURP, the City of Monterey mapped watersheds, major storm drains, key streams,

creeks and channels. They also identified and mapped automotive servicing facilities, restaurants, several industrial sites,

and pest and weed management activities as potential sources of runoff pollution. Fifteen potential sources or activities

that could contribute primary pollutants of concern were identified. The City has adopted a water quality ordinance and

established a monthly storm water utility fee, currently $3.43, to implement its urban runoff management plan.

In cooperation with the Sanctuary and Coastal Watershed Council, the City has also initiated a citizens participation

program to label storm drain inlets and perform volunteer monitoring (Urban Watch Stormdrain Monitoring Program). This

volunteer effort led to the development of a Restaurant Outreach program to educate employees and eliminate pollution.

The City has commenced implementation of BMPs for new and existing sources, conducted water quality monitoring,

distributed public education material, and is currently working to implement its construction site pollution prevention

program.

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In cooperation with the Sanctuary, the City has obtained a grant to install and test storm water treatment devices at

the Monterey Harbor and Fisherman’s Wharf parking lots to determine the effectiveness of removing oil, sediment, and

trash.

City of Santa Cruz

The City of Santa Cruz developed a computer-generated map of watersheds and land uses to identify potential

pollutant sources. The City adopted a storm water ordinance in April 1998, regulating all water entering the storm drain

system, prohibiting illicit discharges and connections, and requiring implementation of BMPs published by the City. The

City has drafted BMPs for vehicle service facilities, retail shopping areas, residential areas, and food service facilities. The

City Industrial Waste Inspectors will conduct initial inspections of 100 vehicle service facilities in 1999 to determine any

actions which must be taken to comply with the ordinance, with second inspections scheduled to formally determine

compliance. The City hosted an outreach presentation of the program and the proposed BMPs for the business community

during its Pollution Prevention Week.

City of Watsonville

The City of Watsonville began implementing a storm water program in 1991, through its industrial facilities Source

Control Program, and completed a bilingual storm drain stenciling program in 1992. Subsequent to the development of

the MURP, the City has completed a review of existing programs and policies, developed a new storm water ordinance,

started an illicit connection program that has sampled 50% of the City’s storm drain outfalls, and established a public

education program in cooperation with the Sanctuary. The City plans to implement a municipal, industrial, and commercial

source control program, a targeted educational outreach program, and a construction and new development program.

Monterey Bay National Marine Sanctuary

The Sanctuary’s Water Quality Protection Program addresses a number of water quality issues in addition to urban

runoff and targets nonpoint sources of pollution. The Sanctuary’s program supports the cities’ urban runoff programs by

developing and distributing educational materials on urban pollution and co-sponsoring teacher training workshops with

the Monterey Bay Aquarium. It also collaborates with the City of Monterey on volunteer monitoring programs and public

education. The Sanctuary has prepared a plan for addressing polluted runoff from agricultural lands and has received

commitments from the California Farm Bureau and six regional Farm Bureaus to form a coalition to address this issue.

The Coalition will focus on educating its members on polluted runoff, establishing landowner committees and pilot projects

in several watersheds, and strengthening farm management practices by developing grower self monitoring and serving

as a liaison with the Sanctuary and the Regional Board.

The Sanctuary and the City of Monterey have a cost-sharing agreement, which funds a Sanctuary employee at half

time in return for the development of a City public education program. This agreement is going into its third year, and has

resulted in the development of public education brochures, posters, exhibits, BMP pamphlets, and the Restaurant Outreach

Program. Current work is focused on the development of a Public Service Announcement, a construction site education

program for developers and inspectors, and signage for Monterey’s Harbor.

State of California - Coastal Commission and Regional Water Quality Control Board

Implementation of the MURP has been identified as a priority in the California Nonpoint Source Pollution Control

Program’s first 5-Year Implementation Plan, which the State Water Resources Control Board and California Coastal

Commission developed pursuant to the Clean Water Act and Coastal Zone Act Reauthorization Amendments of 1990

(CZARA). Key actions that the State will undertake include the distribution of copies of the MURP Guidebook to California

cities and the providing of technical support and training to cities developing Urban Runoff Management Plans using the

MURP.

352
The Coastal Commission intends to review the experiences of Monterey Bay Area cities in implementing the MURP

and coordinating with the Central Coast Regional Water Quality Control Board to revise the MURP Guidebook as needed.

The document will be made available to other small coastal cities by printed copies, CD-ROM, or Internet web site.

Summary and Conclusions

The Model Urban Runoff Program project, which is funded through a 319(h) Grant has provided small communities

in the Monterey Bay Area an excellent opportunity to develop their own urban runoff programs and to develop and validate

an off-the-shelf “ how-to” guidebook on development of urban runoff programs. The MURP will potentially benefit over 100

communities in California that will be required to develop urban runoff programs implementing the six minimum control

measures contained in EPA’s draft Storm Water Phase II Rule and the requirements of Section 6217 of the Coastal Zone

Act Reauthorization Act.

References

California Coastal Act of 1976. (P.R.C.§$30000 et seq.).

California Coastal Commission. 2nd Edition 1996. Procedural Guidance Manual: Addressing Polluted Runoff in the

California Coastal Zone.

California Storm Water Quality Task Force. March 1993. California Storm Water Best Management Practice Handbooks.

California Regional Water Quality Control Board-Central Coast Region. Water Quality Control Plan,

Monterey Bay National Marine Sanctuary. February 1996. Action Plan I: Implementing Solutions to Urban Runoff. Water

Quality Protection Program for Monterey Bay National Marine Sanctuary.

Monterey Bay National Marine Sanctuary. 1998. Annual Report for the Monterey Bay National Marine Sanctuary.

City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary,

Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board.

July 1998. Model Urban Runoff Program, A How-To Guide for Developing Urban Runoff Programs for Small Municipalities.

State Water Resources Control Board and California Coastal Commission. July 1999. Draft California’s Nonpoint Source

Pollution Control Program. Volumes I and II.

U.S. Department of Commerce, NOAA, U.S. Environmental Protection Agency-Office of Water. January 1993. Coastal

Nonpoint Pollution Control Program-Program Development and Approval Guidance.

U.S. Environmental Protection Agency. January 9, 1998. National Pollutant Discharge Elimination System-Proposed

Regulations for Revision of the Water Pollution Control Program Addressing Storm Water Discharges: Proposed Rule

U.S. Environmental Protection Agency. January 1993. Guidance Specifying Management Measures for Sources of

Nonpoint Pollution in Coastal Waters.

353
New Stormwater Treatment BMPs: Determining

Acceptability to Local Implementing Agencies

Gary R. Minton

Resource Planning Associates

Seattle, Washington

Paul Bucich

Pierce County Public Works

Tacoma, Washington

Mark Blosser

City of Olympia Public Works

Olympia, Washington

Bill Leif

Snohomish County Surface Water Management

Everett, Washington

Jim Lenhatt

Stormwater Management, Inc

Portland, Oregon

Joseph Simmler

Entrance Engineers

Bellevue, Washington

Steven True

Vottechnics

Federal Way, Washington

Over 200 local governments in the Puget Sound watershed of western Washington require new developments

to install stormwater treatment systems. The retrofitting of existing developments is also often required. With the guidance

of the State of Washington’, each local jurisdiction developed a list of approved treatment technologies, mostly public

domain technologies such as wet ponds and swales, in the mid-l 990’s. Having an approved list raises the issue of how

to add new unapproved technologies, in particular the manufactured technologies such as swirl concentrators and drain

inlet inserts. A protocol is needed by which local jurisdictions can determine acceptability of “unapproved” treatment

technologies. This paper presents a protocol* recently developed to assist local jurisdictions in the Puget Sound

watershed.

Protocol Structure

The protocol has four parts:

1. Performance criteria to compare currently unapproved treatment technologies with currently approved treatment

technologies.

2. Types of data to be used in the evaluation and methods of sample collection.

354
3. Factors that are to be considered in the evaluation other than performance.

4. Content of the report provided to the local jurisdiction by the proponent.

Method to Compare Performance

There are many problems inherent in the development of a protocol, not the least of which is that there is no agreedupon definition as to what constitutes acceptable performance against which to judge equivalency. An informal “standard”

that is much discussed and that has been adopted by some jurisdictions outside the Puget Sound region is 80% Total

Suspended Solids (TSS) removal over all storms less than a specified event.

A one-number standard of 80% may be inconsistent with two complementary observations about the performance of

stormwater treatment systems. The first observation3 is that removal efficiency of sand filters is directly related to influent

concentration: the higher the influent concentration the greater the efficiency. This relationship may hold for other

treatment technologies. The second observation’ in Schueler (1996) proposes that there is a lower limit to the effluent

concentration.

Further, a reasonably strong and direct relationship exists between runoff rate and TSS concentration5. This is

particularly germane to our region with its mild storm intensities. A comparison of data from our region to areas with higher

average rainfall intensities indicates that we tend to have IowerTSS concentrations in untreated stormwater. It is therefore

possible that over an aggregate of storms, we cannot achieve 80% TSS removal in the Puget Sound region.

A more appropriate method to compare approved and unapproved technologies may be to relate efficiency to the

influent concentration. This approach allows the pooling of data from sites with different pollutant concentrations.

The protocol presumes that if we are satisfied with the technologies that are currently approved, we should approve

an unapproved technology with similar performance. Therefore, the starting point is to identify the performance of currently

approved technologies: swales, wet vaults, wet ponds, constructed wetlands, and sand filters. The results are presented

in Figures 1 through 3. The data points in the figures are of flow-weighted composite samples from individual storms. Only

data from studies conducted in the maritime climate of the Pacific Northwest are used.

Although this is a large region, from northern California to southwest British Columbia, comprehensive studies have

been conducted only in western Washington. Data considered acceptable are from two wet ponds, three grass swales,

and two sand filters. The protocol’ provides detail on the studies that were reviewed. The reasons for using only Pacific

Northwest data differ with the technology. With wet ponds there is concern about the possible effect of differences in

regional climates on effluent quality. For sand filters, possibly because of differing sand chemistry, filters used elsewhere

may be able to remove dissolved phosphorus’jand zinc’, a capability our sands do not have. Swales studies conducted

elsewhere do not provide the information needed to judge whether they were sized to criteria similar to that used in our

region.

Figure 1 for TSS is used in all comparisons, and is the first performance requirement that must be met. If the receiving

water is nutrient sensitive, Figure 2 is also used. If the water body is of regional significance because it supports salmon,

a central issue in our region, Figure 3 is also used. Zinc was selected to represent all toxics primarily because it is the only

toxic with influent concentrations that are commonly high enough to allow for the evaluation of efficiency.

Each figure has a “Line of Comparative Performance,” the origins of which are discussed later. Each line is drawn

so that most of the data points fall above and to the left. This is called the region of acceptable performance. The data

points of the unapproved technology under consideration would be plotted using the same format. If most of the data

points fall above and to the left of the “Line”, it can be concluded that the candidate technology is reasonably equivalent.

What constitutes “most” is up to the local jurisdiction. The protocol does not specify a hard rule but offers these

suggestions as to the percentage of data points falling above the “Lines”: TSS, 90%; phosphorus, 80%; and zinc, 90%.

Note that low efficiencies generally occur at low influent concentrations.
FIGURE 1 TSS Evaluation

PNW data - Individual storms

80%

60%++--

40% I I I

*

-60%~. I

-80%

0 20 4 0 6 0 80 100 120 140 180

lnfluent concentration (mg/L)

FIGURE 2 Phosphorus Evaluation

PNW data - lnbividual storms

100%

80%

60%

x

2 40%

.a,

g 20%

a,

E 0%

B

g -20%

K

40%

-60%

%O%j !! // !! !! !! !! II ! 1 ! !! !! 11 !! 11 ! I

180 200

I

Swale

4

Wet pond

Sand filter

0 50 100 150 200 250 300 350 400 450 500

lnfluent concentration (ug/L)

How were the “lines” derived in Figures 1 through 3? Judgment was used to select a point of “irreducible”

concentration, and to draw the line from this point to the upper right. Regarding “irreducible” concentrations: for TSS Tom

Schueler has proposed4 20 to 40 mg/L, depending on the treatment BMP. A value of 15 mg/L was selected because the

data in Figure 1 suggest that 15 mg/L is attainable. For TP (Figure 2), Schueler4 proposed a concentration of 140 to 330

ug/L, depending on the treatment system. A lower value of 90 ug/L was selected for the same reasons as with TSS.

Schueler4 drew no conclusions with regard to zinc. However, his analysis4 suggests “irreducible”concentrations of 36 ug/L

for ponds and wetlands, so 35 ug/L was selected. It should be noted in Figures 1 through 3 that most of the incidents of

low or negative efficiency occurred at low influent concentrations.

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FIGURE 3 Zinc Evaluation

PNW data - Individual storms

.-5

$

20%

0% 7

t

s 40%

.-5

$

20%

0%

3

B

E

-20% I

d -40% I I I I 1

1 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

-60% I I I I

1

-80% I ,

I I I

I

-lnnw. 1 ! ! ! ! ! ! ! ! !

80%

60%

.-“,“I I I I I I I I I I I

0 50 100 150 200 250 300 350 400 450 500

lnfluent concentration (ug/L)

Attempts were made to identify a line of best fit from which confidence limits could be derived under varying

assumptions such as excluding all data below a particular influent concentration and/or removal efficiency. However, the

relationships were so poor as to make confidence limits meaningless. It was concluded that basing the lines on some sort

of statistical construct would give an air of rigor that is unwarranted at this time. Therefore, the lines were drawn using best

professional judgment. It is expected that the Lines of Comparative Performance will change with time as additional data

are collected.

Figures 1 through 3 can be used for inlet inserts if these pollutants are being considered. If, however, an insert is being

considered for the removal of petroleum hydrocarbons, it must be compared to the effectiveness of oil/water separators.

A graph comparable to Figures 1 through 3 is not provided for oil/water separators because of the lack of data. The

criterion commonly used in the Pacific Northwest is that the concentration of individual samples shall not exceed 15 mg/L.

This protocol could be used to generate data to compare to this criterion.

Data and Data Collection

It is the responsibility of the proponent of the unapproved technology, either the manufacturer or the development

engineer, to obtain the required data. The protocol identifies the minimum requirements. Local jurisdictions are free to

request more data. The protocol specifies the requirements for three sources of data: field studies with real storms, field

studies with artificial storms, and laboratory tests. The protocol calls for discussion of advantages and disadvantages of

each method. It is left to the local jurisdiction to decide the weight to place on each source of data. However, the protocol

recommends that the local jurisdiction not rely solely on laboratory tests, particularly when considering the removal of

dissolved pollutants or oil/grease and related products. It also recommends a size distribution of sediment for the

laboratory tests.

The protocol is very specific with regard to the types and amounts of data that are to be collected. This aspect of the

protocol is summarized in Table 1.

Table 1. Data Requirements

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Item Requirement

Number of test sites One to three sites: medium density residential, retail commercial, and non-retail commercial.

Number of sampled storms

Storm depth

Runoff duration

Average rainfall intensity

Type of samples

Minimum aliquots per storm

Storm volume sampled

Parameters

Additional

A minimum of 10 per site, total of 30 if one site

50% to the design storm depth (1.35’ to 1.70”)

50% to 200% of the mean annual storm duration (7.5 to 30 hours)

50% to 200% of the mean annual intensity (0.02 to O.OB”/hour)

Flow-weight composite

10

Samples are to be taken over not less than 75% of the total volume of each storm

TSS, pH, total zinc, copper, and cadmium, TP, BAP, and TKN. include dissolved metals and phosphorus if it

is claimed that the technology can remove dissolved constituents. With catch basin inserts where the sole

objective is the removal of petroleum hydrocarbons, measure oil/grease, TPH, TSS, and pH.

At the end of the test period, the sediment accumulated in the treatment system shall be removed, quantified,

and anlyzed. The sediment shall be evaluated for total dry weight, moisture content, particle size distribution,

organic content, and zinc. Use ASTM wet and dry sieve test procedures to analyze the particle size distribution.

Also determine the amount of floatables, i.e. litter, and petroleum products.

The protocol states that for a data point to be used in the analysis of efficiency, the influent concentration of the

parameter shall either be at least ten times its detection limit, or be greater than the “irreducible” concentration, whichever

is greater.

Efficiency is to be calculated three ways.

Method 1: Removal in each sampled storm calculated as:

100 (average influent - average effluent)/average influent

Method #l is required because it provides the data points to plot figures like Figures 1 through 3.

Method 2: Aggregate removal of the sampled storms as:

1 OO(A-6)/A

Where: A = (influent cont. Storm l)(flow Storm l)+(influent cont. of Storm 2)(flow of Storm 2)

+ . . . (influent cont. of Storm N)(flow of Storm N)

B = (effluent cont. of Storm l)(flow of Storm l)+(effluent cont. of Storm 2)(flow of Storm 2)

+ . . . (effluent of Storm N)(flow of Storm N)

Method #2 is specified because it provides an overall efficiency of removal over the period of the research. If the

amount of sediment that has accumulated in the bottom of the treatment facility has been determined from the separate

lab test (See Section A.4) another calculation can be done to check the above estimate of efficiency. This second

calculation is done as follows: subtract B from A, and then compare this difference to the amount of sediment determined

from the separate laboratory test described in Section A.4. These calculations can also be done for zinc and phosphorus.

Method #3 Efficiency based on geometric mean:

1 OO(A-B)/A

Where: A = geometric mean of all influent samples

B = geometric mean of all effluent samples

Method #3 is specified because it is the most correct method of calculating efficiency, although it has been used

sparingly to-date. All influent and effluent data from multiple sites can be pooled.

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Consideration of Factors Other than Performance

The protocol suggests that the local jurisdiction consider additional factors in making a decision should the technology

pass the first requirement of acceptable performance. The protocol recommends the following factors, although the local

jurisdiction is free to include other factors.

l Site characteristics

l Constructability

l Reliability

l Robustness

l Receiving water sensitivity

l Groundwater risk

l Operation and maintenance

9 Habitat creation

l Thermal effect

l Aesthetics

. Recreational use

l Community acceptance

It is left to the reviewer to place a weight on the relative significance of each factor and to develop a scoring system.

For example, the factors could be categorized and weighted as: “critical/necessary, ““important,“and “desirable.“A relative

score, say 1 to 10, could be identified for each factor, and multiplied by the corresponding weight of each of the categories.

Content of the Applicant’s Report

The proponent of the technology is responsible for producing a report for the local government conducting the

evaluation. The protocol provides a very detailed list of items that are to be included in the report.

Explanation of the technology, such as:

l How it works, how it removes pollutants

l Where it is currently being used

l Available models

l Treatment and hydraulic capacities of each model

l Documentation of the treatment and hydraulic capacities

l Sediment storage capacities of each model up to the point of recommended maintenance

. Floatables storage capacities up to the point of recommended maintenance

l Sizing methodology

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9 Materials used in the construction of the product

l Recommended maintenance procedures and frequencies

Documentation of the field studies:

l A description of the test site including: total acreage, total impervious acreage, a description of landscaping if

relevant, the acreage draining to the device if it differs from total acreage. A description of the drainage system

including the size of the sumps, and whether the sumps were cleaned prior to or during the test period

l A description of the model used

l Complete drainage calculations showing the calculations to size the treatment device

l All raw data including laboratory reports. All data are to be reported including rejected data with an explanation for

the rejection

l Statement from the analytical laboratory certifying that the appropriate procedures were followed in the preservation

and analysis of the samples

l Calculation of efficiency of each storm by comparing influent and effluent concentrations

l Calculation of the efficiency for all storms by comparing the total aggregate inflow loading of all storms to the total

aggregate outflow loading for all storms

l A graphic of data points showing influent concentration versus efficiency for each storm sampled for TSS, zinc, and

phosphorus. Plot all data, including rejected data, with an explanation for the rejection

l Start and end times of the precipitation and runoff periods of each sampled storm.

l Start and end times of the sampling period of each sampled storm

l Antecedent conditions during the 72 hours prior to each sampled storm

l Total rainfall depth of each sampled storm

9 Total runoff volume of each sampled storm

l Runoff volume that occurred during the period of sampling of each sampled storm

l Total rainfall during the period of all of the sampling, i.e. from the first storm sampled through the last storm sampled

l Total runoff that occurred during the period of all of the sampling, i.e. from the first storm sampled through the last

storm sampled

. If artificial storms are used, identify the method and application rates of water and translate those rates into

corresponding rainfall intensities

l Statement of certification signed by the proponent indicating that the protocol was followed

Additional considerations with inserts for drain inlets:

l Data showing the effect of accumulated litter and leaves on performance, flow capacities

* The point in the maintenance cycle that the field tests were run: i.e. were the units tested “fresh,” without prior field

exposure or were they in the field for some time

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Documentation of laboratory studies:

l Description of the composition of the test water

l The size distribution of TSS in the influent and effluent

l The test flow rates

l The performance at each flow rate

l Mass balance of influent, effluent, and collected sediment

Conclusions

The protocol offers a reasonable and defensible approach that provides rationale for the consideration of technologies

that are not currently approved for use in new developments as well as for public projects. The protocol is most suitable

for the maritime climate of the Pacific Northwest. It is anticipated that the protocol will change over time, particularly as the

data base for approved technologies becomes more extensive and as we learn from its use. More performance data are

needed for public domain technologies located in our region, in particular wet vaults and constructed wetlands for which

there are currently no data.

References

1.

2.

Washington Department of Ecology, 1992, Stormwater Management Manual for the Puget Sound Watershed.

Minton, G., M. Blosser, P. Bucich, B. Leif, J. Lenhart, J. Simmler, and S. True, in press, Protocol for the Acceptance

of New Stormwater Treatment Technologies in the Puget Sound Watershed, APWA Washington Chapter.

3.

4.

Bell, W., et al., 1995, “Assessment of the Pollutant Removal Efficiencies of Delaware Sand Filters”, Alexandria, Va.

Schueler, T., 1996, Irreducible Pollutant Concentrations Discharged From Urban BMPs, Tech Note 75, Watershed

Protection Techniques, 2, 2, 369.

5. Roundtree, L., 1995, The Relationship Between Rainfall Intensity and Urban Stormwater Constituent Levels: A

Comparison of Puget Sound to Other United States Climates Using Pollutographs, Master’s Thesis, University of

Washington, Seattle, Washington.

6. City of Austin, 1996, Evaluation of Nonpoint Source Controls, 319 Grant Project.

7. Wellborn, C.T., and J.E. Veenhule, 1987, Effects of Runoff Controls on the Quantity and Quality of Urban Runoff at

Two Locations in Austin, Texas, U.S. Geological Survey, Water - Resources Investigations Report 87-4004.

361
By Any Measure.. .

Thomas R. Adams, P.E., Vaikko P. Allen and Andrea Perley

Vortechnics, Inc.

Portland, Maine

The introduction of a diverse array of stormwater quality management tools in the last few years has created problems

for the growing number of individuals and organizations who would like to compare the performance of these tools.

Comparison is complicated by differences in treatment capacities, targeted pollutants, and treatment approaches. Several

methods of evaluation have emerged in response to the need for verification of theoretical performance predictions: yet

none of these “yardsticks’are appropriate in all situations and results from each are often not readily comparable to results

from other measures.

Complicating the matter further is the confusion regarding what is being compared. In some cases, a technology will

be compared with another technology. In other cases, the technology is compared to a performance standard. (Analogy:

My maple syrup may be better than your maple syrup, but does that make it Grade A maple syrup?)

The confusion stemming from this is greater than meets the eye. For example, many specifiying engineers and

hydrologists want to meet a performance standard of 80% TSS removal on an annual average basis. They go to guidance

manuals and product manufacturers seeking something that will meet the standard. As the selection process develops,

they grapple with cost, maintenance, the availability of land needed, and many other issues under the heading of “costeffectiveness” for their clients. But by the time the selection has been made, it has become more a question of who has

the better maple syrup rather than whether or not the selected product meets the standard. That is partly because 80%

TSS removal on an average annual basis is virtually an impossible standard to achieve.

It is not the purpose of this paper to propose the adoption of one standard over another.

It is the purpose of this paper to review the merits of various measures of performance and, more importantly, to

stress that any monitoring program that attempts to measure performance of a stormwater quality management system

should begin with a consideration of how the observations will be reported.

Any monitoring program will consist of:

l Sampling

l Testing

l Reporting

Often, researchers start with the selection of samplers and procede with questions of deployment and maintenance

of the samplers. Onlywhen samples have been collected are the questions of testing, and eventually reporting, given much

thought. We propose that the reporting aspect, even though it is “last” chronologically, should dictate how the testing and

sampling are done. For example, if the report is considered most informative when its focus is the mass of pollutants

removed, as is often the case, there is no need for samplers. To get those results usually requires only the very simple

task of periodically measuring accumulations of precipitated sediments or floatable petroleum products (or other pollutants)

and doing simple arithmetic calculations to determine the mass removed. We know of projects that went to the

extraordinary effort that it takes to procure, set up, operate, and maintain automatic samplers to obtain influent and effluent

concentrations, only to “back into” an estimate of the mass of pollutants removed by a convoluted set of “volume-timesconcentration” calculations. This is a classic case of doing something the hard way, not to mention the very expensive

362
way. So the first rule of thumb for any monitoring project is to decide first how to report the results. Then design the

sampling and testing around the information that is to be reported.

In this paper, we will present the following four “measures” of performance from which to choose in making those

decisions. We consider these measures to be the current “status quo of the art.”

9 Mass of pollutants removed

l Event mean concentration (EMC)

. Lines of Comparative Performance (Minton, et. al.)

l Plotting efficiency versus operating rate

First, we would like to discuss in some detail some of the broader issues involved in monitoring stormwater treatment

systems and measuring and reporting on their performance.

Setting

The setting is nearly always in the field or in a laboratory. We feel that the many benefits of testing in a laboratory are

generally underestimated by technical professionals and non-professionals alike. What we refer to as the setting tends

to be pre-determined well before a study gets underway. Since the setting tends to influence the important decision of

what performance measure is best, this cursory overview is provided for perspective.

Field testing

The drawback with field testing is that it cannot be replicated very well. Every site is different. Every storm is different.

There are “wet years” and “dry years.” There are seasonal variations that can produce easily treated heavy sediment loads

in winter and spring; hard-to-treat loadings, such as pollen and grass clippings, in summer; and moderately treatable

loadings (leaves etc.) in the fall. It is poor science to compare the results of a field test of any treatment system to the

results of a test of the same system at a different time and place.

Still, field testing has tremendous appeal because the stormwater and the sediments are “real.”

l Field testing of individual facilities is usually adopted to evaluate the facility’s performance in comparison to a

performance standard (such as 80% TSS removal) to see if it “measures up.” This setting is the simplest and most

common, and is adaptable to any of the measures. The treatment system can be set up to treat all runoff or it can

bypass flows that exceed the treatment capacity.

l “Side-by-side” field testing of several different facilities is increasingly popular, at least in concept. But, to our

knowledge, this approach has not yet been successfully implemented. A key element is the design of the “flowsplitter” that takes all of the runoff and “splits” it into an equivalent discharge to each treatment system. The easy

part of the design of the flow-splitter is achieving equal flow rates of water to each of the facilities (and even this

“easy part” is not always all that easy). The hard part is getting equal discharge of pollutants to each of the

facilities.

Whether testing an individual system or multiple systems, researchers have the potential to learn something very basic

and very important from field testing that has, to our knowledge, eluded researchers to date. That is the determination of

an appropriate threshold for bypassing peak flows. Consider a site that is estimated by conventional runoff modeling to

discharge stormwater runoff at a rate of 3 CFS in a 1 O-year storm. Consider further two proposals for treatment. One

claims efficiency of 90% and a treatment capacity of 1 CFS. The other claims 80% and a treatment capacity of 3 CFS.

Which treatment option should be selected? If the prevalent standard of 80% is in place, the “safe” choice would seem

to be treating all runoff from a IO-year event with 80% efficiency. But what if price is a factor? Maybe the system with 1

CFS capacity costs less. Even at the same cost, would 90% efficient be preferable to 80%? And with that consideration

363
comes the $64,000 question. Will the system that claims 90% efficiency with a capacity of just 1 CFS even meet the

standard of 80% overall? How much of the pollutant load will bypass the system altogether?

Some proponents of small-flow/high-efficiency technologies have stated that 90% of all storms are less than 1 inch

of total rainfall and, therefore, treating 90% of all rain at 90% efficiency will yield a net annual removal of 81%. This

argument is fundamentally flawed. It assumes that the 90% of rain from small storms carries 90% of the pollutants. This

is simply not the case. The rate of mobilization of virtually all pollutants depends on rainfall intensity, not depth of rain.

Therefore, it is important to treat high-intensity flows resulting from the infrequent event, which tend to carry a

disproportionately high pollutant load.

If 1 inch of rain falls in 24 hours, virtually any system that is reasonably proportioned, designed and, of course,

maintained for the treatment of stormwater will do a good job. Efficiencies of TSS removal should be in the 90% range if

the runoff is fairly dirty with silty-to-fine sandy sediments.

It is questionable, however, as to whether or not all of the runoff would be dirty if the rain that produced the runoff

totaled 1 inch and fell over a 24-hour period. Intuitively, the “last flush” of such a storm would be very clean. But even the

first flush may be very clean in comparison to what it would be if 1 inch of rain fell in 1 hour. This highly variable “dirtiness”

gives rise to another interesting question when trying to measure efficiency. That is the question of how to account for the

inevitable reduction in treatment efficiency when the water to be treated is clean in the first place. No treatment system

can remove what is not there. So it has been argued that some accounting should be made for the fact that there is some

lower limit to the physical treatment that can be provided. Minton’s “Lines Of Comparative Performance” (see figure 2.)

take this important consideration into account and are discussed later.

The “Double Whammy” of the “2-Month Storm”

Infrequent, high-intensity storms are important to the effective treatment of stormwater for two reasons:

l Over time, the higher intensity of less-frequent rainfalls, and the resulting higher stormwater runoff velocity, is what

transports most of the sediment off of streets.

l The treatment facility is overloaded by the high flow of water that is transporting the sediment at the same time that

most of the sediment is being transported to it.

Schueler and Shepp (1993) performed monthly observations documenting a random pattern of accumulation and loss

of sediment in a study of 17 different oil/grit separators in Maryland. Overall, the losses of sediment “outnumbered” the

accumulations. In other words, the observed systems lost previously accumulated sediments once every two months.

We have inferred from their work that the “2-month storm” is a reasonable benchmark for stormwater treatment. To be

“measurably” better than the poorly reputed conventional oil/grit separator, a system or a facility should be able to

demonstrate, at a minimum, that it can continue to function in the 2-month storm. If a system is found to lose sediment

in a 2-month storm, it should not be considered any better than conventional technology. Similarly, if a system needs a

bypass to protect it from washing out in 2-month storms, it should be considered only marginally better than conventional

oil/grit separators. Bearing in mind that high flows transport much of the total sediment, treatment systems should be able

to handle more than theSmonth storm without bypass. Otherwise, much of the total sediment load may be discharged

to the receiving waters that the system is supposed to protect.

Clearly the statements of the preceeding paragraph are more of a hypothesis than a statement of fact. One way to

validate or invalidate the hypothesis is described in the following section on side-by-side testing in the field.

Side-By-Side Testing

Testing stormwater facilities “side-by-side” has recently become a very popular idea. The premise is that a well-run

comparison of systems treating “the same stormwater and the same pollutants at the same rates of flow” will go a long

way to reduce the tremendous “scatter” in the data that has been obtained to-date by testing individual systems at different

sites. If two systems are evaluated at different sites, even if the study is carried out by the same researchers using the

364
same protocol, the results will probably not be comparable. Every site is different, and from the point of view of stormwater

treatment, differences that appear slight can actually be significant. We have observed a dozen systems installed on a

single site (a large shopping mall parking lot) which were specified by the same engineer and installed by the same

contractor at more or less the same time and, of course, subjected to the same weather. They exhibited decidedly different

results when we measured sediment accumulations in the systems. The sediment depths ranged from a light dusting to

accumulations of over two feet in less than a year.

So it is important in “side-by-side” testing that there be just one flow stream to the two (or more) systems being tested

and that the flows be split, so that each system gets exactly the same rate of flow and the same pollutant concentration

at all times.

The main benefit of “side-by-side” testing is that it can provide an answer to the question, posed earlier, of whether

it is preferable to have, the arrangement should be as shown in Figure 1.

lnfluent Sampling

Point 1

\

80% TSS Removal Efficiency

Treatment Capacity of 6.0 cfs Effluent Sampling

Point 1

/

Bypass 1

Bypass 2

Figure 1. Recommended Arrangement For Side-by-Side Field Testing.

By sampling at points 1 and 2, the overall efficiency of the treatment system and bypass can be assessed objectively.

Also, the question of “Which is the better system ?” is answered. There are two shortcomings:

. Lack of repeatability. If one system gets 80% efficiency overall and the other gets 70% overall during one year of

testing, there is no assurance whatsoever that either number will be repeated the next year. The test results should

be regarded as indicative of performance. They are certainly not an assurance of performance over time. Such is

the inconsistency, or “noisiness,” of stormwater treatment data. A study like this should be conducted over a period

of no less than two years. If the second year’s results are reasonably close (in terms of statistical correlation) to the

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first, it can be considered complete. If not, it would be tempting to average all results. We feel that it would be poor

science to do so, however. With the seasonal variability of stormwater pollutant loadings, one year’s results will

produce a single data point. A second year’s results will produce a second data point. Many people seem to regard

each storm result as a single data point, but as long as standards continue to be based on “average annual removal

efficiencies,” that is simply not the case.

l Variability with other sites. We have already mentioned the differences from one site to the next. The basic premise

of side-by-side testing is to determine relative performance of two or more systems (i.e., which is best). As long as

such a study is limited to this premise, the variability from one site to the next will not be a problem. But we know

from experience that any “study,” even the most cursory, tends to be overly generalized. We can only caution

against doing so.

Laboratory Testing

Testing stormwatertreatment systems in a laboratory setting offers somevery significant advantages over field testing.

l It is repeatable and demonstrable.

l It is more productive in the sense that decades of rainfall can be simulated in a matter of days.

l It is more economical in terms of labor, sampling equipment, and flow-metering equipment costs.

Laboratory testing achieves these benefits by controlling operating rates, particle sizes, and pollutant loading. When

influent concentrations are very low, removal efficiency will be low; but for concentrations that are generally recognized

as representative for stormwater, all concentrations tend to produce comparable removal efficiencies.

In the lab, a set of tests can be run using one particle size (at representative concentrations) at operating rates from

zero to the system’s capacity. At the conclusion of these tests, a curve can be drawn plotting efficiency versus operating

rate on the y-axis and x-axis, respectively. Such a curve typically slopes downward to the right, reflecting reduced

efficiency and higher operating rates. Any point along a constructed curve should be reasonably reproducible when using

the same influent sediment load.

Subsequently, a whole family of other curves can be constructed using different particles. Also, to more closely

simulate “typical” sediment, a graded sediment sample can be developed and tested in the same way.

Laboratory testing should not be considered the “last word” in documentation of a system’s performance, but can be

considered a “benchmark” which is very useful in comparing systems operating at flow rates up to their capacity. Some

field testing, where it is feasible, should supplement the work in the lab and, as previously discussed, side-by-side field

testing is the only way to determine the impacts of bypasses on different systems.

The Four Most Common Measures of Performance

1. Mass of Pollutants Removed

This is easily the simplest approach to stormwater treatment measurements in the field. By measuring the depths of

sediment accumulations in the facility on a periodic basis, it becomes a simple arithmetic exercise to calculate the volume

and mass of sediments removed by the system.

Additional information is made available by this measurement. It may be recalled, from our earlier discussion of the

2-month storm, that Schueler and Shepp used measurements of sediment accumulations to document the poor

performance of conventional oil/grit separators.

Researchers should consider using the same approach for the newer technologies that have come along since their

important work was published. The approach can be made even more informative by correlating observations to such

366
things as activities in the drainage area (e.g., winter sanding, sweeping, a spill, etc.) or meteorological events such as

observed rainfall intensities or precipitation depths.

2. Event Mean Concentration (EMC)

These are sometimes referred to as “flow-weighted” or “flow-based composite” samples. They are nearly always

obtained using automatic samplers, a flow-meter and a flow totalizer that arithmetically converts the flow rate measured

by the flow-meter to flow volume over time and keeps track of the volume.

The sampler receives a signal that causes it to take a sub-sample when a programmed volume of flow is measured.

For example, one sub-sample might be taken every 200 cubic feet of flow through the system. Over the course of the

storm, all sub-samples would be combined into one large sample container from which the concentration will be obtained

that represents the flow- weighted average for the entire storm.

Without a flow meter, the samplers could be set up to take a “time-based composite” sample; i.e., to sample every 30

minutes. Flow-weighted samples are much more representative, as a simple example will show. Consider a volume of

1,000 gallons with a uniform concentration of 300 mg/l flowing at a uniform rate past the sampling point in 15 minutes,

followed by half as much volume (500 gallons) with a 100 mg/l concentration flowing by in the next 15 minutes. The correct

representation of the concentration would be calculated as:

(1,000x300)+(500x100) =223

1,000 + 500

Flow-weighted sampling will more accurately reflect this. For example, if the sampler were programmed to pull a

sample every 500 gallons, then 2 samples at the higher concentration would be taken and just one at the lower

concentration. The average concentration would be calculated as:

300 +3300+100 =223

Time-based sampling would, if the programmed time interval were 15 minutes, take one sample with a concentration

of 300 and another with a concentration of 100, and the average would be calculated as:

300+100 =200

2

Automatic samplers that can take flow-based composites have become a very valuable tool for sanitary engineers

measuring concentrations of pollutants in wastewater. We believe that they have been too quickly applied to stormwater

monitoring without regard for some of the inherent differences. Waste streams have “highs and lows” of both flow rate

and concentration, but they are not nearly as wide as the variability of stormwater, which can change from flow rates of

zero to a deluge in a matter of minutes and concentrations that can also exhibit a minimum of zero. These “spikes” can

cause very brief periods of negative efficiency if a system is prone to washing out (as stormwater systems were shown

by Schueler and Shepp to do regularly). If a wash-out occurs, it is an important phenomenon to note, but the briefly

elevated concentration in the effluent will be “composited” with the rest of the (presumably lower) effluent samples. This

will reduce the “event-mean-concentration,” but will not reveal that a washout has occurred. Noting washouts, and the

flow rate that caused them, is a very important aspect of a stormwater monitoring program; but they are not likely to ever

be revealed by EMC data.

The second drawback of EMC data is that when influent concentrations drop to very low levels that cannot be further

reduced by physical treatment, the efficiency, as measured by EMC’s, will be reduced. This tends to obscure the fact that

higher efficiencies can be achieved when they need to be achieved; i.e., when influent concentrations are higher.

3. Minton’s “Lines of Comparative Performance”

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It is widely acknowledged that there is a lower limit to the capabilities of physical treatment systems for stormwater.

This means that it is very unlikely that effluent concentrations would ever be zero. It also means that very low

concentrations would not be significantly reduced.

Minton et. al. has proposed the following mathematical expression to describe this lower limit:

Injluent - LowerLimit

Znfruen t

If the lower limit is 20 mg/l, then a plot of this expression is that shown in figure 2.

Performance Standard = (Influent Concentratip - Lower Limit) / Influent Concentration

100% , f

60 80 100 120 140 160 180

lnfluent TSS Concentration (mg/L)

-2OmglL Lower Limit

Figure 2. Line of Comparative Performance.

Plotting individual data points on such a graph can be very informative. Observed efficiencies above the line

(designated a “line of comparative performance” by Minton) are considered satisfactory, while those below the line are

unsatisfactory. Best of all, EMC’s can be used without unfairly representing the efficiency. While the efficiency may be

reduced by low influent concentrations, it may still be shown to be “satisfactory.” More research will be needed to

determine what is an appropriate lower-limit value to use in this approach.

4. Plotting efficiency vs. operating rate.

This approach was essentially described earlier under the heading of Laboratory Testing. By using discrete sediment

particles in the laboratory, a family of curves such as those in Figure 3 can be developed.

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Pollutant removal efficiency vs. operating rate for various particle sizes

t-‘100 Micron ’

*75 hlirmn :

**

. ..--I# -!+ b3 Micron _“ll-..

0 20 40 60 P 80 100

Percent of maximum opeating fate

Figure 3. Removal Efficiency versus Operating Rate.

Field data is less likely to fit the relatively tight curves that can be generated in the lab. At the same operating rate,

you may have vastly different influent concentrations, particle gradations, organic content, etc., depending on such factors

as the time of the storm, anticedent dry period, and time of year. Removal efficiency is a function of all of these factors

combined.

We feel that this performance measurement technique and presentation is the most informative. Its repeatability under

controlled conditions makes it ideal for comparing one system to another. Certainly, if one system’s performance curve

on lOO-micron particles, for example, is higher at all flow rates than another, it could reasonably be judged to be the higher

efficiency system. If the curves are similar at low rates of operation, but either system drops down to zero efficiency at

some higher flow rate, that flow rate should, of course, be considered the peak capacity for that system. This approach

cannot show compliance with any standard for a stated percentage of TSS removal on an annual average basis.

Conclusion

To our knowledge, these four measures represent all of the techniques that have been used to measure the

effectiveness of various stormwater treatment systems.

Measuring sediment accumulations in the field provides a good deal of useful information on mass removals and the

ability to retain (or fail to retain) previously captured pollutants during periods of high flow. This approach costs very little

to implement.

Event-mean-concentrations are the most widely accepted measure, but may not report all efficiencies and will almost

certainly allow any failures to go undetected. This approach requires the use of automatic samplers at considerable cost,

in terms of both time and money.

Minton’s Lines of Comparative Efficiency are more fair to the treatment system because they account for the inability

of any system to remove pollutants that are not present (or present in very low concentrations). If EMC data is collected

to plot against the lines, then there are the same drawbacks of cost and automatic samplers allowing failures to go

undetected. Both of those drawbacks can be overcome, but only with a very dedicated effort to take samples manually.

Taking manual samples throughout the duration of all storms is very time-consuming and unpleasant work. For that reason,

it is almost never done.

369
Plotting efficiency versus operating rate, whether in the field or in the laboratory, is arguably the most informative

approach. In the field, automatic samplers are used (with individual samples in individual bottles and not cornposited), so

there are those costs to consider. In the lab, samplers are needed but the construction of a model treatment facility, and

the pumps and tanks to handle the required flow rates and volumes of water, will more than offset that cost saving.

Since none of these measures provides an ironclad confirmation that the widely prevalent standard of 80% TSS

removal is being met, we submit that a different standard should be adopted by stormwater management jurisdictions.

References

Minton, Gary, M. Blosser, P. Bucich, B. Leif, J Lenhart, J Simmler and S. True, in press, Protocol for the Acceptance of

New Stormwater Treatment Technologies in the Puget Sound Watershed, APWA Washington Chapter.

Schueler, Tom and David Shepp, The Quality of Trapped Sediments and Pool Water Within Oil Grit Separators in

Suburban Maryland, Metropolitan Council of Governments, 1993 (revised).

370
Stormceptor Hydrology and Non-point Source

Pollution Removal Estimates

G. Bryant

Stormceptor Canada

Etobicoke, ON, L3T 3K2, CAN

R. Grant

New England Pipe Wauregan, CT, 06387, USA

D. Weatherbe

Donald G. Weatherbe Associates

Mississauga, ON, L4X 1 H7, CAN

V. Berg

Stormceptor Corporation

Rockville, MD, 20852, USA

Abstract

A model has been developed to estimate total suspended solids (TSS) removal using Stormceptor, an oil/sediment

separator. The model was based on a commonly used, continuous simulation model United States Environmental

Protection Agency Stormwater Management Model (USEPA SWMM) for hydrological processes. The suspended solids

loading was estimated using build-up and wash-off equations. The solids were assumed to be distributed into five particle

sizes for settling calculations. Simulations were conducted using various assumptions of loading and settling velocities to

determine the sensitivity of the model to assumptions. Simulations were also conducted for a diverse range of geographic

areas to determine the sensitivity of the TSS removal rates to regional hydrology. The model was sensitive to the selection

of settling velocities and pollutant loading. The model was less sensitive to changes in hydrology, although significant

changes in hydrology did impact TSS removal estimates.

Keywords: Stormwater; suspended solids; model; hydrology; Stormceptor, separator

Introduction

The Stormceptor is a mechanical water quality separator designed to remove oil and sediment from stormwater. A key

feature of the design is an internal high flow by-pass to prevent scouring and re-suspension of previously trapped

pollutants. Since the separator is based on treating “the everyday storm,” the effectiveness of the separator is dependent

on the distribution of pollution in stormwater and the frequency and magnitude of stormwater flows throughout the year.

In 1995, sizing guidelines were derived for the Stormceptor based on field monitoring of sludge accumulation over time

in Toronto, Ontario, Canada. The accumulation data were used to derive estimates of annual total suspended solids (TSS)

removal. Two key assumptions were made in the 1995 analysis to estimate TSS removal: (1) a TSS loading rate of 185

mg/l based on the USEPA’s Nationwide Urban Runoff Program (NURP) median (U.S. Environmental Protection Agency,

1983), and (2) a sludge water content of 75% water. Actual Toronto rainfall data, combined with the NURP TSS

concentration, provided estimates of annual TSS loading. Figure 1 shows the performance relationship derived from the

Toronto monitoring, which forms the basis for the existing sizing guidelines.

Toronto rainfall time-series data (5 minute timestep) were input to a continuous hydrologic simulation model (SWMM

Version 4.3) to determine the percentage of annual runoff treated based on the sizing criteria shown in Figure 1. The

371
100.0

90.0

80.0

$ 70.0

3 60.0

is 50.0

2 40.0

2 30.0

+ 20.0

10.0 I I I

I I I 0.0 I I 1 I I

0.0 5.0 10.0 15.0 20.0 25.0

I

Total Stormceptor Storage (m3/ha)

Figure 1. TSS Removal versus Stormceptor Total Storage (Toronto, 1995).

analysis of Toronto rainfall indicated that 80% - 90% of the annual runoff would be treated if the Stormceptor were sized

according to these 1995 guidelines. This study was initiated to address concerns about the applicability of the Torontobased sizing criteria to meteorological conditions in other regions.

Methodology

A computer simulation model was developed based on USEPA’s SWMM Version 4.3. Solids build-up, wash-off, and

settling calculations were added to the hydrology code to estimate suspended solids capture by the Stormceptor.

The model accommodates the use of either an EMC (event mean concentration) or build-up/wash-off calculations to

estimate suspended solids loads. The build-up/wash-off model is more theoretically and physically correct. The EMC

method has been shown to provide reasonable estimates of total solids loads (Charbeneau and Barrett, 1998) alone, if

the distribution of the load is not important.

The distribution of pollutant load is important for measures that incorporate a high-flow by-pass (commonly known as

“first flush” measures). Accordingly, preference is given to the build-up/wash-off calculations to correctly distribute the

pollutant load with flow, recognizing the need to optimize the sizing of small-site stormwater quality measures.

In the model, solids build-up and wash-off are both approximated using an exponential distribution. The distribution

of solids build-up is a function of antecedent dry days according to Equation 1 (Sartor and Boyd, 1972).

Where:

P, = Pi + (PA-P,)( 1 -e-‘)

Pt = solids accumulation up to day t (kg)

P = maximum solids build-up (2.4 kg/ha)

A = drainage area (ha)

(1)

Pi = initial solids load on the surface (not washed off from the previous storm) (kg)

k = exponential build-up factor (0.4) (days-‘)

t = antecedent dry days

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The maximum solids build-up (P) load was adjusted to provide similar long-term solids loading rates (124 mg/l) when

compared to the EMC method. An exponential build-up factor (k) of 0.4 was used based on previous literature (SWMM

4.3 Users Manual). A k-value of 0.4 translates into 90% of the maximum solids build-up occurring after 5.66 days. Once

the pollutant build-up reaches the 2.4 kg/ha limit, additional build-up is not allowed (assumed to be wind resuspended/driven off the surface). Wash-off is estimated using Equation 2.

P, = Pie-kv

Where: Pt = solids remaining on the surface at day t (kg)

Pi = initial solids load (from equation 1) (kg)

k = exponential decay factor (0.2) (mm-‘)

V = volume of accumulated runoff from the surface (mm)

The exponential decay factor (k) of 0.2 was based on a review of previous literature that indicates k-values range from

0.03 to 0.55 (Alley, 1981; Charbeneau and Barrett, 1998).

Charbeneau and Barrett (1998) found that the simple wash-off model adequately described observed solids wash-off

in Austin, Texas. Other researchers have cited that the wash-off Equation (2) is reasonable for fine material but may not

be reasonable for larger solids that require a high rainfall intensity for mobilization (Metcalf and Eddy, 1991; Ball and

Abustan, 1995). The SWMM model treats wash-off as a function of the runoff rate to account for mobilization. This

correction is applied indiscriminately to the entire solids load and does not account for the variation in wash-off rate with

particle size. If an “availability” factor is applied to all particle sizes uniformly, the model will underestimate the wash-off

of solids with increasing runoff volume if the majority of particles are fine in size. The approach taken in this study was to

use an availability factor for particles 400 pm in size or larger. Smaller particles follow the simple wash-off estimates given

by Equation 2. The larger particles (2 400 pm) require greater runoff intensities to induce wash-off according to the

availability factor provided in Equation 3.

Where:

A = 0.057 +0.04(r)‘,’

A = availability factor

r = runoff rate (mm/h)

(3)

Equation 3 is based on research by Novotny and Chesters (1997). The runoff rate is used instead of rainfall intensity,

recognizing that the wash-off will lag the rainfall based on the time of concentration. The availability factor varies each

timestep and is only applied to the runoff volume for that timestep, as dictated in Equation 4. The availabilty factor has an

upper limit of 1.

V = Vi + A(V,) (4)

Where: V = accumulated runoff volume used in Equation 2 (mm)

Vi = accumulated runoff volume prior to current timestep (mm)

A = availability factor (equals 1 for particles smaller than 400 pm)

V, = runoff volume for current timestep (mm)

The correction in Equation 4 effectively re-defines the accumulated runoff volume to be the runoff volume sufficient

to mobilize the particles. This methodology requires more accounting in the model but provides a more physically correct

wash-off model.

The separator was treated as a completely stirred tank reactor (CSTR). Alterations to the concentration of solids in

the separator will vary according to Equation 5 (Tchobanoglous and Schroeder, 1987).

C’V = QC, - QC, - r,V (5)

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Where C’ = the change in concentration of solids in the tank with time (kg/m3s)

Q = flow rate through the tank (m”/s)

Ci = solids concentration in the influent to the tank (kg/m3)

C, = solids concentration in the tank (kg/m3)

V = tank volume (m3)

r, = reduction in solids in the tank (kg/m3s)

For gravity settling devices r,can be estimated using Equation 6.

r, = V&/D (6)

Where rc = reduction in solids in the tank (kg/m3s)

Vs = settling velocity of solids (m/s)

D = depth of tank (m)

C = concentration of solids in the tank (kg/m3)

Substituting Equation 6 into Equation 5, solving the first-order differential equation and integrating provides the general

form of the non-steady state solution (Equation 7) for the concentration in the tank at time t.

Where

C = QC/(V(V$D + QN))( 1 -e.(vs/D +a/v)t) + C,e’(VS/D + QM’

C = concentration in the tank at time t (kg/m3)

Ci = concentration in the flow influent to the tank (kg/m3)

C, = concentration in the tank at the beginning of the timestep (kg/m3)

Q = flow rate through the tank (m”/s)

V = volume of water in the tank (m3)

V, = suspended solids settling velocity (m/s)

D = tank depth

t = time

(7)

Equation 7 was used to estimate the suspended solids concentration in the tank, and in the discharge from the tank

each timestep. Equation 7 assumes the suspended solids are completely mixed within the tank volume.

During periods without flow (inter-event periods) the solids are not assumed completely mixed at the beginning of each

timestep and the depth of suspended solids in the separator decreases each timestep until all of the solids are removed

or there are subsequent flows into the separator. The concentration of solids in the tank during periods without flow was

calculated using Equation 8.

Where:

C = C, (1 -V,t/ D)

C = solids concentration in the tank (kg/m3)

C, = initial solids concentration in the tank at the beginning of the timestep (kg/m3)

V, = settling velocity (m/s)

t = timestep (s)

(8)

D = depth of solids in the separator (m)

The depth of solids (D) in the separator in Equation 8 decreases each timestep based on the settling velocity until all

of the solids are removed or there are subsequent inflows to the tank.

The model can be used with either hourly or 15 minute rainfall data. Fifteen minute data are preferred, recognizing that

the Stormceptor is only applicable for small drainage areas. Small drainage areas have short times of concentration and

require data with a suitable timestep. Internally, the model performs calculations with a 5 minute timestep.

374
The choice of particle size distribution and settling velocities is a key part of the modeling exercise. Different settling

velocities can be applied to the same particle size distribution, based on the specific gravity of the particles or to account

for the effect of non-ideal settling or flocculation on settling. In this study, a typical stormwater particle size distribution

(USEPA, 1983) was used for analysis (Table 1). The distribution given in Table 1 is commonly accepted by most regulatory

agencies in North America.

The model allows the user to alter the percentages of each size based on site-specific conditions, if required. In most

areas, it is anticipated that the particle size distribution will not vary significantly since it is primarily related to vehicle wear

and atmospheric deposition. There may be certain instances, however, where the native soils contribute loading and the

default distribution needs to be altered. The default percentages were used in our study.

Table 1. USEPA Default Particle Size Distribution

Particle Size (pm) % by Mass

20 20

60 20

130 20

400 20

4000 20

Settling velocities were then assessed for each of the particle sizes provided in Table 1. Settling velocities were either

calculated or based on empirical literature (USEPA, 1983). The calculation of settling velocities for small particles follows

Stokes’ law (Equation 9) since the Reynolds number (Equation 10) is less than 0.3.

Vs = g (p, - p,)d2/1 8u (9)

Where Vs = settling velocity for particle diameter d (m/s)

g = gravity (m/s’)

ps = density of particles (kg/m3)

P, = density of water (kg/m3)

d = particle diameter (m)

u = viscosity of water (kg/ms)

N, = V,dpJu (10)

Where N, = Reynolds number

Vs = settling velocity for particle diameter d (m/s)

p, = density of water (kg/m3)

d = particle diameter (m)

u = viscosity of water (kg/ms)

If the Reynolds number is greater than 0.3, drag on the particles reduces the settling velocity. An iterative solution was

used (solving for the Reynolds number, drag coefficient, and settling velocity until changes in the settling velocity were

insignificant) for particle sizes with the Reynolds numbers. The drag coefficient is given by Equation 11, and the settling

velocity is calculated by Equation 12.

C, = 24/N, +3/(N,0.5) + 0.34 (11)

Where C, = drag coefficient

N, = Reynolds number

Vs = (Wp, - pwWWopw))“~5 (12)

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Where Vs = settling velocity for particle diameter d (m/s)

g = gravity (m/s’)

p, = density of particles (kg/m3)

p, = density of water (kg/m3)

d = particle diameter (m)

C, = drag coefficient

Table 2 provides a comparison of the settling velocities used in this study.

Table 2. Discrete Particle Size Settling Velocities (mm/s)

Particle Size (pm) S.G. = 1.3 calculated S.G. = 1.8 calculated S.G. = 2.65 calculated USEPA (1983) empirical

20 0.07 0.17 0.36 0.00254

60 0.59 1.57 3.23 0.02540

130 2.50 5.70 11.20 0.12700

400 16.00 37.00 65.00 0.59267

4000 180.00 300.00 450.00 5.50330

S.G. = Specific Gravity

The settling velocities that are based on the empirical USEPA data are 65 to 150 times smaller than the settling

velocities based on a specific gravity of 2.65. A specific gravity of 2.65 is commonly associated with sand-size particles

whereas the fines in stormwater are commonly associated with a lower specific gravity. The use of a higher specific gravity

may be justified, however, if the values are considered representative of the settling velocities of fines in a flocculated or

coagulated state. Research indicates that there is a high potential for coagulation amongst particles (Ball and Abustan,

1995) which will increase settling velocities and TSS removal rates. Furthermore, historical settling velocity calculations

have been based on discrete particle methodologies (vertical settling column tests) that do not account for potential

coagulation. Coagulation would effectively offset the settling velocity columns in Table 2 (i.e., discrete settling velocity for

60 pm represents coagulated 20 urn particle size).

Numerous field tests on the Stormceptor (Labatiuk, 1996; Henry et al., 1999; Bryant, 1995) have indicated a high

percentage of fines in the Stormceptor. This empirical evidence lends credence to the coagulated settling theory, indicating

that the USEPA discrete particle settling velocities may underestimate actual TSS removal rates. Settling velocities based

on a specific gravity of 1.8 were chosen in this study as the default or benchmark selection. The solids loading was

segmented into the particle size distribution and the concentration of solids in each particle size was tracked individually

during the settling calculations.

Meteorological Data

Rainfall data from the City of Toronto (5 minute timestep, 0.25 mm resolution, 10 years record, 1987-1996) was

agglomerated into 15 minute data for use with the model. Fifteen minute data were obtained for the entire U.S.A. from

Earthlnfo on CD ROM. Stations were selected based on location, period of record, data resolution and completeness

within the period of record. Data were also obtained from CSR Humes for various stations throughout Australia. The rainfall

data were converted into National Climatic Data Center (NCDC) format for input to SWMM.

Fifteen minute data were utilized, recognizing the small time of concentration that would typically be encountered in

most Stormceptor applications. Simulations were also conducted using hourly data to determine the sensitivity of the

results to the precipitation timestep. Numerous hourly stations were available on the Earthlnfo CD for this purpose. The

model uses a 5 minute timestep at all times regardless of the rainfall timestep.

Modeling Parameters

SWMM models catchments and conveyance systems based on input rain, temperature, wind speed, and evaporation

data. Only rain data were used in these analyses. The default SWMM daily evaporation values (2.5 mm/day) were used.

Evaporation data will not be important in this analysis since the catchment area is small (c 10 ha) and has minimal

376
depression storage. The Horton equation was chosen for infiltration. The method of infiltration chosen is unimportant due

to the small amount of pervious area (1%). Table 3 provides a list of the parameters used in the SWMM model.

Table 3. SWMM Area Parameters

Area - ha (ac)

Imperviousness

Width - m (ft)

Slope

Impervious Depression Storage - mm (in.)

Pervious Depression Storage - mm (in.)

Impervious Mannings n

Pervious Mannings n

Maximum Infiltration Rate - mm/h (in/hr)

Minimum Infiltration Rate - mm/h (in/hr)

Decay Rate of Infiltration (s?)

variable

99%

variable

2%

4.7 (0.19)

0.5 (0.02)

0.015

0.25

62.5 (2.46)

10 (0.39)

0.00055

The width of catchment was assumed to be equal to twice the square root of the area.

Results

EMC versus Build-up/Wash-off

The suspended solids removal results based on the build-up/wash-off model were compared to those based on an

EMC of 124 mg/l (USEPA, 1983) to demonstrate the sensitivity of the model to the different solids loading approaches.

The use of an EMC assumes an equal concentration of suspended solids in all of the stormwater that is conveyed to the

Stormceptor.

Figure 2 shows a comparison of results using an event mean concentration loading and build-up/wash-off loading,

given the default particle size distribution and settling velocities based on a specific gravity of 1.8.

The results in Figure 2 show that the TSS removal rates using the EMC approach are lower by 14% when compared

to the build-up/wash-off method even though the total loads are similar. This is expected due to the by-pass nature of the

Stormceptor. The estimated TSS removals for the existing (1995) sizing guidelines, which are based on an early field study, are lower

than both the EMC and build-up/wash-off estimates for low values (50% TSS removal) of separator storage/drainage area and are higher than the other

estimates for larger values of separator storage/drainage area (80% TSS removal).

The range of TSS removal values based on computer modeling is smaller than the empirical TSS removal rates.

Doubling the size of unit for the same area results in an increase of 30% for TSS removal, based on the current sizing

guidelines, whereas the increase in performance based on the modeling is less dramatic (a 5% to 10% increase in TSS

performance). This finding indicates that the modeling results will be less sensitive to changes in the model size for any

given drainage area.

Selection of Settling Velocities

A comparison was made regarding the choice of settling velocities using Toronto rainfall data and the build-up/wash-off

TSS generation methodology. Figure 3 provides the results of this analysis. The TSS removal estimates using the USEPA

settling velocities are an average of 20% lower than the original TSS removal estimates, 29% lower than the estimates

using the SG=1.3 velocities, and 39% lower than the estimates using the SG=2.65 velocities. These results indicate that

the TSS removal performance results are very sensitive to the selection of settling velocities.

377
Figure 2. TSS Removal vs. Loading Methodologies

6.00 8.00 10.00 12.00 14.00

Storm ceptor Storage (m 3ha)

16.00

L

Figure 2. TSS Removal vs. Loading Methodologies.

Annual F/o w Treatment

Numerous regulatory agencies design stormwater quality measures using a “design” event. The design event used

generally ranges from the 25 mm storm, or annual storm, to the 25-year storm. The modified SWMM program was used

to calculate the percentage of annual runoff that would be treated (not by-passed) with different by-pass flow rates. This

analysis was conducted using the Toronto rainfall for a drainage area of 2.25 ha. Figure 4 shows that the volume of runoff

that is treated prior to by-pass quickly becomes asymptotic with increasing treatment flow rate. A device that treats 30 Us

prior to by-pass would treat approximately 80% of the annual runoff. A device that treats 70 L/s (over 2x higher flow rate)

only treats 10% more runoff (90%). Although the relationship between conveyance (% of annual runoff treated) and TSS

removal is non-linear, Figure 4 shows that high-rate treatment devices are not required for small drainage areas.

The relationship provided in Figure 4 will vary with local meteorological conditions and is inherently accounted for in

the TSS removal modeling.

Regional TSS Removal Performance Analysis

The model was used to compare results from different areas in North America and Australia to determine the effect

of regional hydrology on TSS removal performance. All analyses were conducted using 15 minute rainfall data and based

on the TSS build-up and washoff model and settling velocities for a specific gravity of 1.8.

Table 4 shows the results for various sized Stormceptors with a 2 ha drainage area. The locations of stations listed

in Table 4 were selected to cover a wide geographic area, provide rainfall on a 15 minute timestep with a 0.25 mm

resolution, and provide results representative of large nearby cities. Most data from city airports are recorded hourly, and

therefore were not included in the comparison. The results in Table 4 are plotted in order of decreasing performance

expectations in Figure 5.

Of the 16 stations analyzed, 12 stations provided TSS removal estimates within *5% of the Toronto values.

Although the majority of stations provided similarTSS removal estimates, there were areas with significant differences.

The performance estimates were lowest for the southeastern United States. This area is well know for its intense seasonal

rainfall distribution. Figure 5 indicates that the TSS removal rates may vary up to 20% under different hydrological

conditions on the same land use/site conditions. The use of local or regional rainfall data is therefore appropriate for design

purposes.

378
Figure 3. TSS Removal Performance vs. Settling Velocities

90%

;:-;

Q) 40% - OA 0 •I SG=1.3

p!

0 ’ VT

v) 30% -

~~ -__

0”

” ,o m SG=1.8

2

A SG=2.65

20% -

0 Existing Siziq

10% -

0% I

6 8 1 0 1 2 1 4 1 6

Stormceptor Storage (mYha)

Figure 3. TSS Removal Performance vs. Settling Velocities.

80

60

Figure 4. Annual Runoff Treatment

(Toronto - 2.25 ha)

40 60

Flow Rate (L/s)

Figure 4. Annual Runoff Treatment.

379
Table 4. Regional Comparison of TSS Removal Performance (2ha)

State/ Province Location Stormceptor Model (CDNIUSA)

3001 750J 15OOl 30001 5000/ 6000/7200

450 900 1800 3600 6000

Colorado Fort Collins

Alberta Calgary Forest

British Columbia Vancouver

California Davis

Massachusetts East Brimfield Lake

Ontario Toronto

New South Wales Sydney

New York Rhinebeck

North Carolina Cataloochee

Queensland Brisbane

Minnesota Le Sueur

California Orange County

Maryland College Park

Missouri Miller

Florida St. Lucie New Lock

Texas Houston Addicks

49%

48%

48%

44%

43%

43%

42%

41%

41%

41%

41%

37%

34%

30%

27%

63%

63%

65%

61%

59%

58%

57%

57%

56%

55%

56%

57%

53%

50%

43%

41%

65%

65%

66%

63%

61%

60%

59%

59%

58%

57%

57%

59%

54%

51%

44%

42%

71%

71%

71%

69%

67%

66%

66%

65%

64%

64%

84%

65%

61%

59%

52%

49%

Figure 5. Regional Comparison of TSS Removal Performance

(2ha)

3001450 7501900 1500/1800 300013600 5000/6000 6000/7200

Stormceptor Model (CDNIUSA)

80%

z

g 70%

E 60%

2 50%

76% 79%

76% 79%

76% 78%

74% 77%

73% 75%

72% 75%

72% 76%

71% 74%

71% 74%

71% 74%

70% 74%

71% 74%

67% 70%

65% 69%

59% 64%

57% 61%

Figure 5. Regional Comparison of TSS Removal Performance

Rainfall Timestep

An analysis was conducted to determine the sensitivity of the model to changes in rainfall resolution. Results based

on hourly rainfall data (0.25 mm resolution) were compared to those based on 15 minute rainfall data, to determine the

impact of using the hourly data. Hourly data are more readily available than 15 minute data and most large cities have

airports that collect rainfall on an hourly basis.

The model reads the hourly data as rainfall that falls during the first fifteen minute timestep of each hour. This will

produce higher intensities since the rain is not distributed correctly over the entire hour. The greater intensity is

compensated for, however, by the completeness of the hourly records which translates into a greater number of small

rainfall values.

Four areas were analyzed (Rockville, Maryland; Boston, Massachusetts; Miami, Florida; and Houston, Texas). The

results of this analysis (Figure 6) indicate that the use of hourly data does not significantly alter the TSS removal estimates

380
for units that are designed to remove over 40% of the annual TSS load. Greater discrepancies can be expected at large

ratios of drainage area to separator storage.

Figure 6. TSS Removal versus Rainfall Timestep

(by Stormceptor Model)

90%

80%

70% -

g 60% -

4 MA (60 min)

ii --t MD (15 min)

g 50% -

--b MD (60 min)

5 40% - p! +FL(15min)

g 30% - -e-FL (60 min)

+

20% - + TX (15 min)

10% -

-e-TX (60 min)

0% 1

1 2 3 4 5 6

Stotmceptor Model

Figure 6. TSS Removal vs. Rainfall Timestep (by Stormceptor Model).

Conclusions

The TSS removal results were sensitive to the selection of settling velocities for the specified particle distribution.

Differences in TSS removal of up to 40% were obtained, depending on the settling velocities that were evaluated.

Results were also affected by theTSS loading method. The use of an EMC underestimated TSS removal performance

by approximately 15%, when compared to using the build-up and wash-off equations. This difference is expected since

the EMC method increases the load that is by-passed and provides higher loads during higher treated flow rates when the

detention time, and hence settling effectiveness of the unit, is reduced.

The model indicates that high percentages of the annual runoff can be treated with low-flow treatment devices such

as the Stormceptor. The model also predicts that the TSS removal performance is less sensitive to the size of separator

than observed from previous field studies.

Regional hydrology affected the TSS removal estimates provided by the model. Although differences of up to 20%

were observed, significant hydrological differences between the sites were needed to obtain this variance. Most of the

rainfall station locations tested provided TSS removal estimates similar to those of Toronto, where the original sizing

guidelines were developed.

Testing the model with different rainfall timesteps (15 minute versus hourly) indicated that hourly rainfall records can

provide an adequate estimation of performance if the rainfall is collected at adequate resolution (0.25 mm increments).

The modeling indicated that significant TSS removal rates can be achieved using small infrastructure control measures

if the drainage area is limited. The results lend credence to the positive field monitoring results obtained to-date for the

Stormceptor, and to the concept of small storm hydrology being the predominant parameter for urban stormwater quality

design.

381
References

Alley, W., Estimation a Impervious-Area Washoff Parameters, Water Resources Res., 17, 1161, 1981

Ball, J., and Abustan, I, &I Investiqation of Particle Size Distribution durina Storm Events from an Urban Catchment,

University of New South Wales, 1995

Bryant, G., Misa, F., Weatherbe, D., and Snodgrass, W., w Monitorinq a Stormceptor Performance, 1995

Charbeneau, R., and Barrett, M., Evaluation a methods for estimatinq stormwater pollutant loads, Water Environment

Research, Volume 70, Number 7,1998

Henry, D., Liang, W., and Ristic, S., Comparison of Year-Round Performance for Two Tvpes of Oil and Grit Seoarators,

Draft paper, 1999

Labatiuk, C., Nataly, V., and Bhardwaj, V., m Evaluation of 3 Pollution Abatement Device for Stormwater Qualitv

Improvement, CSCE Environmental Engineering Conference, Edmonton, 1997

Novtony, V., Unit Pollutant Loads, Water Environment & Technology, 1992

Novtony, V., and Olem, H., Water Quality: Prevention, Identification, S, Manaqement of Diffuse Pollution, Environmental

Enaineerina Series, Wiley & Sons, 1997

Sat-tar, J. , and Boyd, G., Water Pollution Asoects of Street Surface Contaminants, EPA-R2-72-081, U.S> Environmental

Protection Agency, Washington, D.C., 1972

Tchobanoglous, G., and Schroeder, E., Water Quality, University of California at Davis, 1987

Tchobanoglous, G., and Burton, L., Wastewater Enoineerina, Treatment, Disposal & Reuse, Water Resources &

Environmental Enaineerinq, McGraw-Hill, 1991

U.S. Environmental Protection Agency, Final Report of the Nationwide Urban Runoff Proqram, Water Planning Division,

Washington, D.C.,1983

U.S. Environmental Protection Agency, Storm Water Manaqement Model, Version 4.3. User’s Manual Washington, D.C., --I

1988

382
NPDES Phase II Cost Estimates

Andrew J. Reese, P.E.

Ogden Environmental and Energy Services, Inc.

Nashville, TN, 37211

Introduction

The United States Environmental Protection Agency (EPA) has published final rules expanding the existing stormwater

NPDES permitting program to smaller cities and other urban areas throughout the United States. Due both to external

pressures and directives from the current and past administrations, EPA is conscious of attempting to make the current

stormwater NPDES program “cost-effective.” For example:

“EPA believes this rule will cost significantly less than the existing 1995 rule that is currently in place, and will result

in significant monetized financial, recreational and health benefits, as well as benefits that EPA has been unable

to monetize, including reduced scouring and erosion of streambeds, improved aesthetic quality of waters, reduced

eutrophication of aquatic systems, benefit to wildlife and endangered and threatened species, tourism benefits,

biodiversity benefits and reduced siting costs of reservoirs.” ’

‘I.. . the Agency recognizes the continuing imperative to assure that environmental regulations accomplish statutory

objectives in the least burdensome and most cost-effective fashion. As explained further in this preamble, the form

and substance of NPDES permits to address the sources designated in today’s proposal would provide greater

flexibility for the newly covered sources than the existing “standard” NPDES permit.“’

While the “benefit” side of the proposed regulations exists in the realm of gross estimates, the “cost” side is also filled

with unknowns. What will the mandated and negotiated stormwater program cost a local community? Are there ways to

reduce costs? What should a local community be doing now to prepare for this regulatory program? This paper seeks

to address these related questions.

The final regulations were published on December 8, 1999 and the changes from the draft regulations are only mine?.

But it is still not possible to say what the regulations will cost everyone in toto. This is so because:

l there is great flexibility inherent in the regulations to create a stormwater quality program tailored to meet an

individual community’s needs and situation;

l each permit writer has preferences and “hot buttons” that will color what any particular program will look like; and

l each community setting is different in terms of climate, topography, pollutants of concern, and current condition of

local waters.

’

2

Federal Register, January 9, 1998 p. 1536

ibid. p. 1550

3 Federal Register, December 8, 1999 pp. 68722-68851

383
Basic Approach to Permitting

Under proposed 5 123.35(g), an NPDES permitting authority issues a general permit to authorize stormwater

discharges from regulated small municipal separate storm sewer systems. The NPDES permitting authority will also

provide a menu of regionally appropriate and field-tested Best Management Practices (BMPs) that the permitting authority

determines to be”cost-effective.“The regulated small municipal separate storm sewersystems could choose to select from

this menu or select other BMPs that they feel are appropriate.

Under Phase II each regulated community will need to develop a set of BMPs under each of six specific program

minimums. These BMPs can be any combination of programs, structures and other controls that, in the agreed opinion

of the permit writer and the regulated community, meet the standard of reducing pollution discharge to waters of the state

to the Maximum Extent Practicable (MEP). In this process, permittees and permit writers would evaluate the proposed

stormwater management controls to determine whether reduction of pollutants to the MEP could be achieved with the

identified BMPs. EPA envisions that this evaluative process would consider such factors as condition of receiving waters,

specific local concerns, and other aspects included in a comprehensive watershed plan.

Under the proposed approach, implementation of BMPs consistent with stormwater management program

requirements at 9 122.34 and permit provisions at 9 122.33 would constitute compliance with the standard of “reducing

pollutants to the maximum extent practicable.” That is, “if you do what you say you will do, you are by definition in

compliance.” It is important to note that states implementing their own NPDES programs may develop more stringent

requirements than those proposed in the Federal Register. In fact, we anticipate that many states will require more specific

and rigorous requirements under special circumstances relating to the condition of the receiving water within, and

downstream from, the community. For example, if a certain stream is required to have a Total Maximum Daily Load

(TMDL) or similar study performed on it (for example, a watershed assessment for the purposes of wastewater treatment

plan permitting or expansion), the NPDES stormwater Phase II permit conditions may reflect the allocation of pollutants

to that community.

The steps for a community are: (1) review the conditions of the general permit, (2) develop and submit a Notice of

Intent (NOI) to comply with the general NPDES permit through description of a BMP-based program under each of the six

minimum controls or program areas (see below), (3) negotiate this proposed program with the permit writer, (4) receive

approval of the submittal, and (5) begin implementation of the conditions and programs described in the NOI including

record keeping and submittal of appropriate reports describing attainment of “measurable goals” for each BMP as

described in the NOI.

Current NPDES Phase II Program Cost Estimates

There is naturally much speculation on the actual program elements and costs for a particular stormwater program

developed under Phase II. There have been several attempts at estimating Phase II program costs based on current costs

of “similar” programs.

In the draft regulations, EPA had provided estimates of the probable cost implications of the NPDES Phase II Permit.

These estimates were based on summary information from the permit applications from 21 Phase I cities. Very high and

very low figures were thrown out by EPA in developing these estimates. Figure 1 shows the summary table developed by

EPA.

The range depicted in Figure 1 is from $1.39 to $7.83 per person per year for the first permit five-year period, and

$1.28 to $5.63 for other permit cycles. For a city of 50,000 that is a very wide range of $69,500 to $391,500 annually for

the first permit cycle. This is clearly not helpful in attempting to estimate a specific community’s costs.

There is question about the vagueness in the regulatory language, and the high degree of potential flexibility inherent

in briefly described program elements. For example, for the first of the minimum controls the regulatory language states:

384
Figure 1. EPA Cost Estimates for Phase II NPDES Compliance.

1. Public education and outreach on storm water impacts4.. You must implement a public education program to

distribute educational materials to the community or conduct equivalent outreach activities about the impacts of

storm water discharges on water bodies and the steps that can be taken to reduce storm water pollution.

(You may use stormwater educational materials provided by your State, Tribe, EPA, or, subject to the approval of

the local government, environmental or other public interest or trade organizations. The materials or outreach

programs should inform individuals and households about the steps they can take, such as ensuring proper

septicsystem maintenance, limiting the use and runoff of garden chemicals, becoming involved in local stream

restoration activities that are coordinated by youth service and conservation corps and other citizen groups, and

participating in storm drain stenciling, to reduce storm water pollution. In addition, some of the materials or outreach

programs should be directed toward targeted groups of commercial, industrial, and institutional entities likely to

have significant storm water impacts. For example, information to restaurants on the impact of grease clogging

storm drains and to garages on the impact of oil discharges. You are encouraged to tailor your outreach program

to address the viewpoints and concerns of all communities, particularly minority and disadvantaged communities,

as well as children.)

The “regulatory” wording in parentheses is not mandatory but suggested. There is wide room for interpretation of the

intensity and detail necessary to accomplish this minimum control. The devil is always in the details, and there will always

be great variability in what two different programs intend to do to accomplish the same general goals.

NAFSMA (1999a, 1999b) published a survey on potential Phase II program costs responded to by 121 cities and

counties nationally. Ten communities responded with programs that had three or more suggested elements in the first

minimum control: Public Education and Outreach. The annual per capita costs for these ten ranged from $0.04 to $1 .17

- again a wide range.

Of those responding, only one communitv stated that it had program activity in each of the six minimum control

measure areas and it spent $15.11 per capita annually, well above the EPA estimate (the city has a population of about

25,000). Of the 121 respondents only 26 had programs in at least three (most had onJ three) of the six mandatory

minimum control areas, and these can be considered far from complete. Figure 2 shows the distribution of costs for these

26 programs. The vertical axis is the annual per capita cost for these elements. The median was $1.44 and the average

was $4.07. The low value was $0.04 and the high was $26.00.

4Federal Register, January 9,1998, p. 1639.

385
sm.00

524.00

s22.00

sm.00

S1800

Sl6.00

914.00

$12.00

s lo.00

$800

Sam

s&m

szm

s- -.--.m.

- - -E--is. L r; F: z

Figure 2. NAFSMA Study Program Costs.

We can speculate that if many of these communities had a fully developed Phase II program, the average costs could

more than double, since each community would be adding both new program areas and upgrading their existing programs

they had to make them comply with the details of the Phase II permit writers requirements.

In the final regulations, USEPA took a different approach to making estimates of the costs of compliance, using both

the NAFSMA information and past experience with Phase I (EPA, 1999). EPA estimated annual costs for the municipal

programs based on a fixed cost component and a variable cost component. The fixed cost component included costs for

the municipal application, record keeping, and reporting activities. On average, EPA estimated annual costs of $1,525 per

municipality. Variable costs include the costs associated with annual operations for the six minimum measures and are

calculated at a rate of $8.93 annually per household (assuming 2.62 persons per household). The the cost estimating

equation is:

Annual cost = $1,525 + population/2.62*$8.93

Finally, rule of thumb estimates based on the author’s experience working in over 100 communities indicate that

comprehensive stormwater programs that include advanced stormwater quality programs cost between $7.00 and $20.00

per capita per year - above the EPA estimates. The quality portion is normally between 20 and 30% of the total average

program cost.

Estimating Costs from Anticipated Programs5

The methods used above do not provide details of the components of the stormwater programs resulting in the costs,

and thus are not very helpful in assisting other communities in their thinking about the regulations. An effort was made

to develop cost estimate ranges based on a direct interpretation of the stormwater regulations as applied to example

communities at each end of the spectrum, in terms of size and intensity of water quality program. This has an advantage

in that it deals directly with the stormwater regulatory requirements and illustrates specific program components so that

we can control and define all details. The following sub-sections will develop two hypothetical permit applications for the

six minimum controls.

Permittee one (“Smallville”) is a community of 10,000 that is adjacent to a larger city that has obtained a Phase I permit

or that can assist Smallville in many of its permit responsibilities. It is a small bedroom community interested in compliance

with minimum disruption and cost. It does not really have an engineering or planning component of its city staff, but relies

on a city administrator and hired consultants.

’ Based on a presentation made by Andy Reese of Ogden Environmental at the APWA seminar, “Designing and Implementing an Effective Storm

Water Management Program, Denver, 1998.

386
Permittee two (“Midtown”) is a larger and more self-contained community with a population of 50,000 located within

an urbanizing county whose total population makes it a designated “urbanized area.” It is aggressively annexing growth

areas, and has a thriving economy. It has a City Engineer/Public Works director, road maintenance staff, and other

municipal capabilities and resources. It also has a growing stormwater quantity program and wishes to bring quality

together with quantity in a comprehensive and integrated approach. It wants to take advantage of its GIS database and

capability.

The Programs

We can assume that contained within, or subsequent to obtaining the general permit, the permit writer will publish a

list of regionally appropriate BMPs to be used in permit applications. The general permit will have narrative effluent

limitations which describe goals or narrative standards for each of the minimum controls. Each permittee must then

develop basic program objectives and measurable standards (not included here) under the goals provided by USEPA for

each of the six minimum controls. These measurable standards can be stated in terms of actions taken or results

achieved. It is best to state them in terms of things that can be controlled and which do not have uncontrollable and

unpredictable results.

It is also smart to schedule the programs (the schedule is not demonstrated here) in terms of phases, pilot programs,

demonstration projects, trials, etc., with an evaluation process at some point in the permit. It should then be written into

the NOI that this program will be modified, expanded, curtailed or even abandoned if it is not effective.

Smallville sought to obey only the letter of the law, but did not see many ways to proceed. It had no real stormwater

program, no known water quality problems, and few current responsibilities. This community sought to take advantage

of “big brother” next door in joint programs or education, and to adopt more regionally uniform development regulations

enforced locally. Smallville sought to fund any program needs through budget changes and through economies gained

by taking advantage of regional programs, free information, and expanding duties of existing staff.

Midtown sought to meet the program minimums in a more proactive way focusing on perceived needs within the

community. They took advantage of the strength of existing local programs, a strong economy, a strong environmental

awareness, and outside assistance where available in the form of copied resources and shared efforts. Midtown expanded

its current program using EPA suggestions to build a more comprehensive and meaningful program in several key areas6.

Because they did not have the ability to try to work regionally (the adjacent county had no resources for developing a

stormwater program, but would cooperate as necessary) it needed to build the program alone and to work extra-territorially

as appropriate. Midtown looked at each program to insure the existence of: adequate legal authority, competent technical

approach, dedicated financial resources and appropriate administrative procedures and staffing.

Because program funding became an issue, Midtown sought to establish a stormwater user fee system (often called

a stormwater utility) to provide stable, adequate and equitable funds. The costs and steps of the utility development are

not included here.

Program Objectives

Table 1 develops the basic objectives of each of the programs in each of the six minimum areas. In real life these

objectives would be developed through a series of discussions with staff and, perhaps, a citizen’s group, and through early

coordination with the permit writer.

Table 2, which is attached as an Appendix, gives basic cost-estimate information for the two programs. The costs are

approximate and would vary depending on how all costs are accounted for, availability of staff, etc. The intent is to give

ballpark estimates and not to quibble over details. In these estimates all personnel time is costed at $50/hr regardless of

6 NAFSMA has taken an earlier version of the Midtown values, refined them, and developed a minimal and advanced program concept out of this

information. That information can be obtained from NAFSMA by calling 202-218-4122.

387
the source of the labor (in-house or contracted). This corresponds to a fully burdened salary rate plus allocated overhead

costs for a mid-level technical person.

Table 1. Basic Program Objectives

Smallville

Public Education and Outreach on Stem, Water Impacts

Midtown

1. Acquire and mail existing public domain informational brochures 1. Acquire and mail existing and specifically pertinent public domain

2. Encourage and facilitate newspaper articles informational brochures to the general public

3. Educate the few industrial and commercial stakeholders individually 2. Develop a stratified database of stakeholder groups and develop

and execute targeted education programs

3. Develop and implement elementary school education programswith

preexisting curriculum

4. Develop and advertise complaint hotline as a pollution hotline

5. Develop press information and briefings with the objective of having

a quarterly news article

6. Develop and make available a slide show and speakers bureau

Public InvolvemenVPatticipation

1. Develop and implement a citizens advisory group appointed by the mayor 1. Develop and implement a stratified and diverse citizens advisory

2. Encourage citizen participation in the neighboring city’s programs for group/task force

used oil, household hazardous waste, adopt-a-stream, etc. through news 2. Develop a citizen monitoring and/or adopt-a-stream program -- may

articles in local neighborhood newspaper be partially federally funded

3. Develop a student storm drain stenciling program and student dry

weather screening program (see illicit connections program)

4. Encourage the development of watershed groups for each major

watershed within the jurisdiction (see BMP control)

Illicit Discharge Detection and Elimination

1. Develop a stormwater major outfall map on USGS base map 1. Develop a major stormwater system map and inventory on existing

2. Modify slightly and adopt a generic ordinance available from the state or GIS topo. Base mapping

other organization. 2. Cross-reference map with existing databases on NPDES permit

holders (available from the state) and SARA Title Ill database to

identify likely source of dry weather pollution

3. Develop an illicit connections and illegal dumping ordinance

including hotspot program

4. Perform initial dry weather screening in several key parts of the city

by student volunteers

5. Develop inspection and enforcement capabilities and resources,

and develop a detection program using city staff and a database of

potential specific locations

6. Advertise hotline and write news articles (see public education)

7. Advertise existing private used oil disposal sites (see public

education)

8. Educate all public employees to recognize and report problems (see

pollution prevention)

9. Develop automotive industry sponsorship of spill prevention,

materials management, and inspection and education programs

(see public education for part of this)

Construction Site Storm Water Runoff Control

1. Modify the adjacent city’s sediment and erosion control ordinance to 1. Modify existing sediment and erosion control ordinance to

meet the regulatory minimums include all the requirements of the regulations

2. Modify plans review and inspection procedures to include program 2. Add a BMP section and clear design steps to the drainage

minimums manual

3. Train city secretary to collect phone complaints and take appropriate 3. Conduct training and familiarization program for developers,

action on erosion complaints contractors and engineers, as well as in-house training for

4. Advertise the complaint line as part of the public education program. inspectors

4. Insure hotline has a formal and defined ability to receive and

properly process erosion complaints

5. Upgrade the erosion control inspection and enforcement

program

388
Post-Construction Storm Water Management in New Development and Redevelopment

1. Modify and adopt the adjacent city’s stormwater ordinance regarding 1. Investigate and seek to institute zoning and policy changes to

stormwater quantity and quality requirements to require similar controls encourage density restrictions, transferable development rights,

and requirements. Add a maintenance requirement for BMPs and easier use of PUDs, limitation of impervious areas, conservation

detention designs easements, mandatory floodplain dedication, etc.

2. Transform the inspection process to be able to inspect and enforce the 2. Develop design guidance for the use of structural and nonnew ordinance structural BMPs

3. Communicate the new requirements 3. Develop and conduct an ongoing training program in the proper

use of BMPs

4. Develop several BMP pilot projects to demonstrate and gain

experience in BMP use

5. Overhaul and develop a comprehensive storm water ordinance

for both water quantity and quality which includes mandatory use

of BMPs and a maintenance requirement

6. Establish inspection program for private BMPs

7. Develop a monitoring program for local surface waters and to

monitor their long term changes

8. Develop master plans for areas facing new development and

establish and enact policy for regional BMP design and

maintenance

9. Develop ways to improve extra-territorial planning and zoning

input

10. Identify key environmentally sensitive areas and take steps to

protect such areas through ordinance, overlay districts, etc.

11. Seek to establish local watershed organizations and

neighborhood adopt-a-stream programs to assist in compliance

and build public support

Pollution Prevention/Good Housekeeping for Municipal Operations

1. Review all current municipal procedures and document ways to reduce 1. Conduct an outside review of all applicable procedures and

pollution criteria and make recommendations for change, implement

2. Make changes and document changes

3. Obtain and distribute materials on ways to reduce pollution as available 2. Obtain available information and conduct sensitivity and

and appropriate. familiarization training for all applicable city employees

3. Seek to control floatables partially through adopt-a-stream

program (see public participation)

4. Review existing flood control projects to insure advantage is

taken of pollution reduction opportunities in design and operation

Hours are given in most cases. Italicized numbers are one-time costs that are experienced some time in the first permit

period, assumed to fill the year in which they initiate. For ongoing programs, the program initiates beginning in the next

year. The annual costs are the anticipated costs thereafter. I have assumed that all programs initiate in year one for the

total five-year cost estimate. Obviously if a program initiates in a later year there will be savings in annual costs not

incurred until the program initiates. The five-year total is four times the annual cost plus the initial cost -- making a total

of five years. Some programs are five-year programs only, ending after the first cycle.

A schedule of tasks and of manpower requirements is not developed in this paper. The costs are given as initial costs

and as ongoing costs (clear from the context of the table). Because not all program elements will be developed and inplace for the whole permit term, there will be a ramp-up process. Also, most of the program elements will continue to

change and evolve over time, and program costs will also change (up or down) in subsequent permit periods.

Extraordinary volunteer efforts have not been assumed (e.g. writing news articles, manning a hotline, etc.).

It is important to realize that some per capita costs go down for large cities because they have a large fixed component.

For example, it may cost the same to develop a one-page brochure whether the city has 20,000 or 200,000 people in it.

Expenses are based on medium levels of effort wherever appropriate. Detailed expenses (e.g. long distance phone costs)

have not been estimated.

389
Measurable goals have also not been provided in this handout. But for each BMP measure or program it will be

necessary to develop some measurable standard by which to judge success. The standard may be based on internal

activities where it cannot easily be based on external results. For example, sending out brochures three times per year

can be measured. But, the effectiveness of those brochures can only be measured through phone surveys of public

knowledge before and after the brochure was sent, or based on statistics on increased public participation in whatever

program the brochure was about. Neither measure is easy and reliable. And, should a certain percent “effectiveness

increase” be stated as the measurable goal, if it is not achieved the city would, technically, be out of compliance. Better

to make the goal controllable, especially in the first permit cycles when little is known on the effectiveness of certain

(especially non-structural) BMP measures.

In no case have the costs of structural BMPs been estimated or included. Cost estimates are available in several

references including the Center for Watershed Protection (1997) and Northern Virginia Planning District Commission

(1994). The economic benefits of structural BMPs are discussed in EPA (1995).

Monitoring costs are developed for Midtown based on both receiving stream monitoring and some pilot BMP program

monitoring; they are non-existent for Smallville. EPA estimates that about 50% of permittees may incur monitoring costs

in subsequent permit cycles. It is also assumed that there are no TMDL or other types of watershed assessment actions

going on in the watershed which may radically modify the permit conditions, and that there are no regional or state-wide

programs which could simply be adopted by reference for portions of the NPDES minimum requirements.

Summary Results

The summary results of the analysis are presented in Table 3, in terms of cost per capita, for each of the programs in

a manner comparable to the EPA estimates.

The range of results is similar to that experienced by EPA in making its original estimates of the cost of the Phase II

program. The details of this program development can assist a local community in fashioning its own stormwater program

in response to the regulations.

Table 3. Summary Results

Minimum Control

Annual Per-Capita Cost

Small Midtown

First 5year Permit Period

1 - Public Ed. 0.39 1.24

2 - Public Inv. 0.21 0.62

3 - Illicit Connections 0.24 1.77

4 - Construction 0.20 0.96

5 - Post Const. 0.14 5.78

6 - Housekeeping 0.15 0.59

Totals 1.33 10.96

Subsequent 5-year Permit Periods

1 - Public Ed. 0.36 1.40

2 - Public Inv. 0.24 0.51

3 - Illicit Connections 0.10 1.16

4 - Construction 0.18 1.10

5 - Post Const 0.13 1.26

6 - Housekeeoina 0.10 0.20

390
The Phase II Action Plan

Given the great range in costs for the Phase II program it makes sense to get a jump start on planning for it. Many of

the requirements or potential inter-local arrangements that could be developed take time to implement, more time than is

available if the community waits until the general permit has been finalized and the NOI is due. There are steps that a local

government should take now to prepare itself for the regulations and to position itself to meet compliance in the most costeffective manner. These steps can be performed as part of a Phase II action plan:

1. Assess your status

Ask yourself if you are “in,” “potentially in,” or “out.” Find out who else is in your category.

2. Get to know the permit writers

Find out what the permit writers are thinking about the permits, what the general permit will look like, when you will

know more, how they will evaluate those potentially in, what other actions are going on in the state that may impact the

permit, etc. Find out their ideas about what is important in the permit, what their special interests are, do they strongly

support the permit, etc. Plan to establish an ongoing dialog.

3. Assess your surface waters

Find out if there are any ongoing actions which might designate surface waters in your jurisdiction as not meeting water

quality standards. See if there are any planned watershed assessments or TMDL requirements coming in the future.

4. Assess your own program

How much of your own stormwater program looks like the regulations, even with some minor modifications. Can you

get a jump on the requirements through transformation of your current programs?

5. Check out your neighbors

Are there some other programs nearby that might result in savings to you? Can you simply be covered under another

program? Can parts of the requirements be waived because they are already being done by someone else? Can you

plan to be part of a regional permit? Can you split the permit requirements with an adjacent entity and perform them

together at savings to both of you?

6. Get a team together

Once you have answered some of these questions, it is time to pull the action team together. This may include only

your own staff, a multi-disciplinary staff within your own jurisdiction, or a multi-jurisdictional or regional team. Get together

to brainstorm and come up with a proposal to the permit writer which has mutual benefits. Remember, permit writers are

being encouraged to think regionally and on a watershed basis.

7. Develop an action plan

Once you have a team, it is time to have a plan. Begin to formulate what you will need to do to apply for the permit

and to carry it out. What might your program minimums look like? Are there some things you can do now, over several

years, that you cannot afford to do in any one year, or that will take too long to get going if you wait until the permit is upon

you? Can you begin the program transformation process now? What about data collection and mapping? Are there other

uses for any data you will collect which will create synergy?

391
8. Get started

Some things are best started early. But do not jump the gun by committing resources in areas that are not yet

anticipated to be firm. Ask the permit writer for his or her opinion.

References

Center for Watershed Protection, 1997, The Economics of Stormwater BMPs in the Mid-Atlantic Region, August.

The National Association of Flood and Stormwater Management Agencies (NAFSMA), 1999a, Phase II Survey Raw Data

Report, 1299 Pennsylvania Ave. NW, Washington DC, 20004.

The National Association of Flood and Stormwater Management Agencies (NAFSMA), 1999b, Survey of Stormwater Phase

II Communities, 1299 Pennsylvania Ave. NW, Washington DC, 20004.

Northern Virginia Planning District Commission, 1994, Urban Retrofit Techniques: Applicability, Costs, and Costeffectiveness, November.

United States Environmental Protection Agency, 1995, Economic Benefits of Runoff Controls, EPA 841-S-95-002,

September.

United States Environmental Protection Agency, 1999, Report to Congress on the Phase II Stormwater Regulations, EPA

833-R99-001, October.

392
Appendix

Table 2. Hypothetical Program Detail and Cost Summary

Smallville

Program Element

Public Education and Outreach on Stonnwater Impacts

Acquisition of available mailers and information from private

institutions and other governmental entities - 20 hrs

cost

$1,000

Midtown

Program Element

Acquisition of available mailers and information from private

institutions and other governmental entities - 40 hrs

cost

$2000

Keep up with available literature - 20 hrs/yr

Coordination with neighborhood or shoppers newspaper to run

articles on pollution sources - 4 hrs

$1 OOO/yr

$200

Keep up with available literature - 50 hrslyr

Stratified mailing database development for key stakeholder

groups - commercial, automotive, minority, etc. - 100 hrs

$2500/yr

$5,000

Develop 2 articles per year - 24 hrs/yr

Coordination with the few individual potential sources of pollution

about the program and their needs - 10 hrs

$1,20O/yr

$500

Maintenance of database - 1 hr/wk

Obtaining or developing educational materials for the specific

outreach and stakeholders’ programs, printing - 30 hr

$2,60O/yr

$4,000

Series of three mailings - stuffers in utility bill $3,600

Updating materials - 100 hrs/yr. Mailing 5,00 brochures per year

Developing outreach and educational programs - 200 hrs

$7,50O/yr

$10,000

One mailing per year afterward

Responding to information requests - l/2 hr/wk

$1,05O/yr

$1,30O/yr

Executing programs - updating, mailing, training, presentations -

200 hrslyr

Develop elementary and middle school education programs - preexisting

Material/curriculum - free materials - 100 hrs

$12,00O/yr

$5,000

Ongoing program maintenance - refresher training, 5 schools - 100 hrslyr $5,00O/yr

Advertising of hotline - radio spots developed in-house and on public $12,00O/yr

And other radio service spots and Newspaper ad, 3 times per year -

140 hrs - donated spots

Develop white paper and press package - initial, brief - 32 hrs $1,600

Develop quarterly press package/briefing - brief press - 24 hrs per + $5,00O/yr

expenses

Development of a short, scripted stormwater pollution slide show, $3,000

Presentation and speakers bureau & initial presentation - 60 hrs

Give presentations - 48 hrs/yr + expenses

General informational brochure development and mailing - once/year

- 60 hrs/yr - 25,000 inserts 0 0.50 per

$2,60O/yr

$15,50O/yr

Continued

393
Table 2. Cont.

Program Element

Smallville

cost Program Element

Midtown

cost

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

Public Involvement/Participation

Development and implementation of a citizen advisory committee

appointed by the mayor - 2 initial meetings - 14 hrs

Quarterly meetings - 32 hrs/yr

Advertisement of the larger city’s stream cleanup program in local

shopper newspapers - news articles, and coordination with them in

all such programs - 16 hrs/yr

$5,350

$4,550

$23,500

$22,750

$700

$1,60O/yr

$800/yr

Responding to information requests - 2 hrs/wk

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5-year periods)

Development and implementation of a citizen advisory committee

appointed by the council - 5 initial meetings - 70 hrs + expenses

Bimonthly meetings - 60 hrs/yr

Initial coordination of monitoring program and/or adopt-a-stream

- 60 hrs - equipment purchase

Ongoing coordination and equipment, database maintenance

$5,20O/yr

$30,600

$69,900

$310,200

$349,500

$3,700

$3,00O/yr

$40,000

$15,50O/yr

- 160 hrs/yr + expenses

Student storm drain stenciling program development and $6,500

implementation - 80 hrs

NOTE: italics are initial cost - for first year only

Annual cost

Watershed group encouragement - presentations, advertising -

50 hrs + expenses

$3,000

$2,800

Initial Cost $700

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

Illicit Discharge Detection and Elimination

Collect and plot field information on system locations and sizes -

5 hrs - contract

Ongoing coordination, education - 4 groups - 20 hrs. per

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5-year periods)

Develop system map, perform inventory of major structures - 60

hrs + contract

$4,OOO/yr

$53,000

$2,400

$10,300

$12,000

$7,000

$25,500

$155,000

$127,500

$150,000

Adopt ordinance - 20 hrs $1,000

Update map - 60 hrs

Database development and GIS programming and mapping -

200 hrs + expenses of $3k

$3,00O/yr

$13,000

Enforcement of ordinance - 20 hrs/yr $1 ,OOO/yr Database maintenance - 100 hrs $5,00O/yr

Continued

394
Table 2. Cont

Program Element

Smallville

cost Program Element

Midtown

cost

Ordinance development with public participation - contract $20,000

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

Modify and pass new erosion control ordinance - 40 hrs

Initial dry-weather screen in parts of city - student volunteers - 240 hrs

One staff member 1 day/week for inspection and enforcement of

Illicit connection program - + expenses

Development of automotive or other specialty programs - 100 hrs +

1 k exp.

Annual implementation of inspection and education - 1 day/wk

$8000 Initial Cost

$1,000 Annual Cost

$12,000 Total Cost (first 5 years) $433,000

$5,000 Total Cost (ongoing 5-year periods)

Construction Sire Stonnwater Runoff Control

$2,000 Modify existing ordinance - public participation - 60 hrs

$12,000

$28,00O/yr

$6,000

$22,00O/yr

$201,000

$58,000

$290,000

$3,000

Enforcement ordinance in inspection process - 50 hrs/yr

Modify development procedures - 4 hrs

Train secretary to handle calls - 8 hrs

Handle erosion calls - 10 hrs/yr

$2,50O/yr

$200

$800

$500/yr

Add BMP section to design manual - 140 hrs + printing cost

Conduct training sessions for staff and local development related

persons - 80 hrs

Ongoing biannual training - 32 hrs/yr

Develop hotline procedure for complaints reception - 10 hrs

$12,000

$4,000

$1,60O/yr

$500

Initial Cost $2,600

Hotline Q 150 hrslyr + expenses

Upgrade erosion control program for more sites and more activities -

one person two dayslwk + expenses

Initial Cost

$8,50O/yr

$45,OOO/yr

$19,500

Annual Cost $3,000 Annual Cost

Total Cost (first 5 years) $14,600 Total Cost (first 5 years)

Total Cost (ongoing 5 -year period) $15,000 Total Cost (ongoing 5year periods) $275,500

Post-Conshuction Stormwater Management in New Development and Redevelopment

Modify and get ordinance passed - 40 hrs $2,000 Work on major policy changes in land use regulations - contract +

200 hours

Enforce/explain new ordinance provisions - l/2 hr/wk $1,30O/yr

Develop design guidance for BMPs - contract

Training program for BMP use - debvelopment - 24 hrs + contract

$55,100

$239,900

$100,000

$25,000

$3,000

Annual training - 60 hrs/yr $3,00O/yr

Continued

395
Table 2. Cont.

Program Element

Smallville

cost Program Element

Midtown

cost

BMP Pilot projects - federal funding assistance - 5-year program -

contract 5 yrs

Comprehensive stormwater ordinance with public participation -

contract

$200,000

$40,000

BMP inspection and enforcement program - one person one day/wk $25,80O/yr

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

$2,000

$1,300

$7,200

+ expenses

Data collection program - SWAG

Master planning for new areas for both quality and quantity - 2 mile

Planning zone around city y p - 5- ear ro ram -40 g mi’

Costs of administration of regional BMP program - SWAG

Sensitive area identification program, ordinances and policy enactment5-year program - 100 hrs incl. Mapping 5 yrs

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5-year periods)

$30,00O/yr

$800,00

5 yrs

$4,00O/yr

$25,000

$393,000

$62,800

$644,200

$314,000

Master planning

Pollution Prevention/Good Housekeeping fo Municipal Operations

Review of all current procedures - modification of procedures - 40 hrs $2,000 Review and modification of all applicable procedures and criteria $25,000

Obtain and distribute educational materials - 10 hrs

Annual cost of changed procedures - SWAG

$500

$l,OOO/yr

contract

Site inspections and corrections - 5-year program - $5k/yr

Training for city employees on new procedures - 40 hrs + 10 hrs @

$25,000

5 yrs

$42,000

75 persons + expenses

T Initial Cost $2,500

Review flood control projects for retrofit opportunities - contract

Annual cost of changed procedures - SWAG

Initial Cost (without master planning)

$15,000

$lO,OOO/yr

$107,000

0

T

A

L

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

$1,000

$6,500

$5,000

Annual Cost

Total Cost (first 5 years without master planning)

Total Cost (ongoing 5-year periods)

Master planning

$10,000

$147,000

$50,000

$800,000

T

0

T

A

L

Initial Cost

Annual Cost

Total Cost (first 5 years)

Total Cost (ongoing 5 -year period)

$21,500

$13,250

$74,150

$66,250

Initial Cost (without master planning)

Annual Cost

Total Cost (first 5 years without master planning)

Total Cost (ongoing 5-year periods)

Master planning

$804,100

$281,300

$1,929,300

$1,406,500

$800,000

396
The Stormwater Utility Concept in the Next Decade

(Forget the Millenium)

Hector J. Cyre, President

Water Resource Associates, inc.

Kirkland, WA

Abstract

In the mid-l 970’s, the first stormwater utilities were viewed as novel innovations in a few western states. Today, just

25 years later, more than four hundred cities, counties, and special districts throughout the United States have established

such utilities. The pace is accelerating, and the stormwater utility concept has moved from a novelty to a well-accepted

management and funding approach. What will we see in the next decade?

The stormwater utility has been adapted to fit diverse stormwater management problems and needs across the United

States. Program content, priorities, institutional and organizational structures, and rate methodologies have been tailored

to fit local needs and municipal authority and practices that vary widely. Courts in several states, and even federal courts,

have been engaged in resolving key issues, including but not limited to the legality of utility service fees and the use of

other funding mechanisms.

Major changes in the concept are still emerging today. Stormwater quality has become a concern equal to flood

control in many communities. The National Pollutant Discharge Elimination System Phase II stormwater permits have

spurred a new round of interest in the stormwater utility concept among smaller communities. This is creating a demand

for basic utility concepts suitable for small cities and towns, which will need to be less costly and simpler to implement and

maintain. Concurrently, more large cities, urban and urbanizing counties, regional service agencies such as metropolitan

sewer districts, and consolidated governments are investigating the utility approach. They will require more complex

institutional and funding solutions.

Stormwater management itself is also changing rapidly. Interest and involvement in stormwater management have

broadened. As combined sewer overflow programs, total maximum daily load (TMDL) negotiations, stormwater quality

mandates, coastal zone management measures, and safe drinking water supply issues converge, more wastewater and

even water supply utilities are engaging in stormwater management. Regional resource management programs,

watershed-based master planning, multi-purpose cooperative efforts involving urban forestry and riparian corridor

protection, and use of state revolving loan funds for stormwater quality projects are becoming more common.

Local programs are quickly evolving as well. They have become more comprehensive in scope, more costly, and more

demanding of technical and administrative skills while the pool of resources has grown relatively slowly. Local

governments are accepting responsibility for more components of the stormwater drainage systems or, in some cases,

being forced to take on such responsibilities. Open streams, historic remnants or agricultural ditches and levees, and

detention facilities are being included among the system components actively improved, operated, and maintained by local

stormwater management agencies, A preventive orientation that minimizes problems is replacing reactive measures.

Technology, such as geographical information systems and hydrologic and hydraulic modeling, is more widely available

and more productive in support of stormwater management, even in smaller communities. Public involvement in decisions,

policies, and even the operation of systems is increasing.

This paper examines these and other emerging trends that characterize where stormwater utilities are heading in the

next decade.

397
Pressures Moving us from Draining the Swamp to Stormwater Management

Historically, local drainage flooding, erosion, and water pollution due to stormwater runoff have not been high priorities

for municipal governments. Unless homes, businesses, valuable agricultural land, or public properties have been

devastated by flooding or other “drainage” problems, competing priorities have generally garnered more public concern

and thus more support from elected officials. As a result, stormwater management operations, regulatory measures, and

capital investment were historically ignored or, at best, received inadequate attention and erratic funding. Stormwater

management has been a “stepchild” among municipal programs.

Symptoms of this past disregard are evident in many cities and counties.

l Improvements to stormwater systems in many communities have been limited to site-specific facilities installed by

subdivision and commercial developers.

. Design practices have traditionally emphasized collecting and discharging runoff from each property as quickly as

possible, without regard for downstream consequences.

. Public maintenance of stormwater systems has typically been reactive, and usually limited to road rights-of-way

where uncontrolled stormwater might impact traffic safety, degrade the integrity of road surfaces, or threaten

valuable adjacent properties.

l Maintenance of stormwater systems located outside of road corridors has commonly been left to private property

owners, who are rarely capable of or willing to properly improve, clean, and repair such facilities.

l Municipal governments have usually improved and maintained individual structures or reaches instead of entire

drainage systems, creating a patchwork of pieces having widely varying capacity and reliability.

l Failures of substandard components frequently impair the performance of otherwise adequate parts of the systems

and damage properties near them.

As described by one municipal public works official, this stepchild is also the “sleeping giant” of unmet municipal

infrastructure needs. Long-term stormwater remedial repair costs potentially exceed street and bridge repair needs in

many older cities. Learning the high cost of correcting stormwater management deficiencies through master planning may

have frightened as many local jurisdictions into inaction as it has spurred others. Perhaps the classic example is the

stormwater master plan for Key West, Florida, which (in the early 1990’s) identified $78 million in capital needs for that four

square mile island community of less than 30,000 people.

Several factors are now changing local governments’ traditional orientation to stormwater management.

l Citizens’ service expectations are higher than in the past. In many cities and counties the number of citizen

complaints about stormwater problems exceeds those about potholes in roads.

l Crumbling inlets and silt clogged ditches along roadsides spawn complaints even though they are on public property.

l Individual citizens or neighborhood associations no longer tolerate minor problems like localized flooding and

channel erosion in backyards.

Environmental awareness in general is greater than in the past, and much more attention is being focused on

stormwater impacts on receiving water quality in recent years.

l Stormwater management is now recognized as being part of an effective water resource protection strategy.

l Local concerns about acute threats of water pollution from spills and surreptitious dumping of toxic materials into

stormwater systems are becoming more common.

l Phase II of the National Pollutant Discharge Elimination System (NPDES) stormwater permitting program is

extending the program to smaller communities and those larger urban cities that escaped Phase I due to combined

sewer service area exemptions.

. Programs proposed by local governments in NPDES Phase II permit applications will cost many thousands of dollars

per year in cities, towns, and urban counties.

398
An encompassing, umbrella perspective of water resource management is emerging.

l Solutions to combined sewer overflow (CSO) problems will have to balance optimization of wastewater transport

and treatment facilities against stormwater quantity and quality concerns.

l Several coastal states have instituted restrictive limitations on stormwater runoff to protect fragile estuaries and

offshore waters from stormwater impacts.

l Drinking water supply watershed protection measures have imposed stormwater runoff regulations on developers

independent of local stormwater management control practices.

l The point is becoming clear. Drinking water is water. Wastewater is water. Stormwater is water. Ground water

is water. It is all WATER!

In the face of these pressures, the inadequacies of traditional stormwater management practices and funding are more

widely recognized. More comprehensive and cohesive programs that address both stormwater quantity and quality are

emerging. Clearly, however, the diversity of our communities and their problems and priorities means that no single

solution is appropriate for every county, city, town, and village. Nor can a single funding method or stormwater utility rate

structure fit every situation. Stormwater service fee methodologies can be designed to meet the specific needs of each

community and provide equitable, adequate, and stable funding. The key is to tailor the funding to a clear program

strategy.

“Stormwater Utility” can have Many Meanings

The fact that the simple term “stormwater utility” obscures the various meanings it may encompass, results in many

misunderstandings. The term may imply a funding and accounting method, an organizational approach, a management

concept, or a combination of all these. In reality a “utility” provides an umbrella under which the financial, organizational,

and management approaches of each local stormwater program can be orchestrated to achieve practical and efficient

solutions. Responsibilities may be consolidated and focused. Substantial new funding may be generated. New

technology, different management concepts, and upgraded support systems may be adopted. A comprehensive,

preventive program may be instituted.

Changes in the Approaching Decade

The spectrum of the stormwater utility concept will broaden more in the next 10 years than it has in the 25 years since

the first utilities were established. The definition of “conventional” will change. Smaller towns and even villages will need

to employ simpler variations of the concept. Larger cities, urban counties, consolidated governments, and coordinated

regional approaches will demand more complex institutional, organizational, and funding solutions. The following are a

few of the changes that may occur.

NPDES Phase II Will Impact the Stormwater Utility Concept

The findings of a survey of Phase II cities conducted by the National Association of Stormwater and Flood

Management Agencies (NAFSMA) and published in July, 1999 indicate that 17% of all the respondent communities did

not know how they would obtain funding to meet the stormwater regulations. Nearly half indicated they were not currently

spending money on any of the stormwater program elements mandated by the regulations. Nearly three-quarters did not

have a public information or education program as the regulations mandate. The 54% of respondents that currently fund

programs or activities that fit the Phase II regulations on average spend upwards of $4,000 per square mile, or about $2.79

per capita. The implication seems clear that the NPDES Phase II program poses demands on local governments that may

cause them to look to the stormwater utility concept to meet their stormwater quality program funding requirements.

The typical community that found the stormwater utility concept attractive in the past was a mid-size to larger city

undergoing rapid development. Analyses of their stormwater management needs and programs typically revealed initial

costs of service ranging from $25,OOO/sq. mile to $5O,OOO/sq. mile annually. Costs per capita were typically $10 to $30

annually, with smaller cities trending toward the higher end of the range. In this context, the NAFSMA survey data is not
alarming. It suggests that the Phase II program costs will likely be in the neighborhood of five (5) to fifteen (15) percent

of the typical cost of stormwater management at the outset of utility-based programs.

Given its cost implications, NPDES Phase II makes the stormwater utility concept attractive to a broader variety of

cities, counties, towns, and villages. Many communities that do not suffer flooding or other drainage problems will find the

revenue potential and flexibility of a utility service fee attractive in the face of NPDES permit requirements. This will result

in utility approaches that are outside the current spectrum of our experience. The needs in individual small communities

may be less diverse than in large cities and urban counties, but the range will be cumulatively broader among the

communities involved in NPDES Phase II than in those that have implemented utilities previously.

New institutional arrangements and relationships will have to be devised. The “utility” concept will take on new forms.

Use of interlocal agreements among several local jurisdictions will increase, with responsibilities in some cases

concentrated in one entity capable of providing the range of services required or, conversely, allocated among several

participants.

The limits of existing authorizing legislation in some states will be tested. Many states will need to adopt new

legislation and amendments, giving local governments greater flexibility in dealing with their water resource management

responsibilities. Courts in the various states, and perhaps even federal courts, will be challenged to arrive at some sense

of continuity among the institutional and financial solutions characterized as “stormwater utilities.” Whether the court

decisions will enable rather than hinder local governments’ efforts to comply with NPDES mandates is a key question.

Organizationally and financially independent stormwater utilities have been common to date. In the next decade more

stormwater utilities will be integrated with other water resource programs: organizationally, through formalized working

relationships, or through financial arrangements. Other resource management agencies and programs, including but not

limited to health departments and growth management authorities, will demand a seat at the stormwater table.

As NPDES permitting is applied to smaller urban areas of less than 100,000 people, more of the regional wastewater

and water utilities already serving those communities will assume stormwater management responsibilities. In some cases

their involvement will be limited to water quality aspects. In others they will address both quantity and quality. Funding

of stormwater management costs will simply be assumed by some of these existing utility agencies without changes in

their rate methodologies. Others will establish independent stormwater cost centers and rate components to track

spending and allocate costs. Some will even modify existing wastewater and/or water rate methodologies to better reflect

the impact of stormwater control on costs of service.

As more small cities and counties seek to establish utilities, stormwaterfunding strategies and rate methodologies will

need to minimize implementation costs, yet be more flexible to accommodate stormwater quality management costs and

unique local needs. The urge to use a “cookbook” solution will cause some to adopt approaches that are poorly suited

to their circumstances. The desire for more precision in service fee rate algorithms will lead to methodologies that give

an illusion of greater refinement without actually achieving it.

The mandated involvement of smaller jurisdictions and more rural communities in stormwater management will spawn

“paper utilities” established solely to generate added revenue. Most of these will be initiated without the foundation of a

solid program strategy. Accountability will become a key issue in some of these communities within a few years. Political

challenges based on accountability issues will cause some of these storm water utilities to be melded into other local

agencies’or programs or even dissolved entirely before they have geared up to address their program priorities.

Despite NPDES storm water permit mandates, locally perceived needs will still predominate in setting priorities.

Flooding will remain a more important local issue than storm water quality. NPDES mandates will influence actual spending

priorities only slightly. Few communities will need to institute a utility service fee just to support their NPDES Phase II

programs, but many will justify it (at least partially) on that basis because it is easy to blame unfunded federal mandates

for new local taxes, assessments, and service fees.

400
The technological resources and expertise required will change from the traditional engineering emphasis to a multidisciplinary mix. More natural science and social science skills will be needed. Operational practices will change as new

technology and information management systems enable innovative approaches and result in greater efficiency. Greater

use will be made of outsourcing because of limited personnel resources and the high cost of specialized equipment.

The Stormwater Utility Concept will Impact NPDES Phase II

Local approaches to stormwater management will influence the content of Phase II permits and attainment of NPDES

objectives. Stormwater utilities offer both financial capability and flexibility. Except in rare instances, stormwater utilities

will not be established strictly to address stormwater quality and NPDES permit requirements. Rather, they will have a

broader stormwater management perspective. For many communities this will mean that water quality management

activities to comply with their NPDES permit will be tacked onto other stormwater efforts. NPDES Phase II permitting will,

within a few years, adjust to accommodate this reality in terms of permit mandates, technical and scientific standards, and

reporting requirements.

Related issues ranging from combined sewer overflow strategies to drinking water protection will be melded with Phase

II permit requirements because they have to be. Local stormwater quality management cannot independently meet the

entire range of regulatory expectations operating strictly by reference to NPDES Phase II. Conflicts and primacy battles

will identify inconsistencies and gaps between the issues and programs, and will ultimately filter down to changes in

NPDES Phase II program priorities and the permit requirements imposed on local governments. The unknown is whether

this result in responsibility shifting toward bigger agencies with more resources and a broader perspective or toward local

entities that have the ability to identify and activate locally acceptable solutions.

Watershed-based regulatory programs will overtake jurisdictional-based regulatory programs like NPDES Phase II.

The utility approach will broaden to encompass watersheds through agreements among counties and cities simply because

utility funding has the proven capacity to generate sufficient funding in politically acceptable ways. The transition has

already begun in some areas. Where TMDLs affecting discharges of all sorts into receiving waters are an issue, they will

supercede the six minimum practices identified for NPDES Phase II, making them essentially meaningless. Scientifically

based, public health driven measures to protect drinking water supplies, estuaries, lakes, fisheries, and recreational

beaches will overwhelm the programmatic approach represented by NPDES Phase II.

You May Need a Program to Identify All the Players

Stormwater utilities were first established because no one wanted responsibility for stormwater management. Those

involved were concerned only about the impact of stormwater on their “real” jobs. The utility approach provided a way to

focus responsibility and obtain dedicated, if not always adequate, funding for stormwater management. If there had been

another option that was working, the stormwater utility concept probably would never have emerged.

A key issue in the next decade will be whether stormwater utilities will be major protagonists or bit players among all

those now crowding onto the stage. More established and better-funded water and wastewater utilities now recognize that

stormwater influences their operations directly and, in some cases, dramatically. For example, TMDL-based wastewater

discharge limitations may severely curtail development in some areas. Will local wastewater utility administrators (and

local elected officials) allow independent stormwater management utilities to address stormwater quality when economic

vitality is at risk?

Other interests are becoming involved in stormwater management. Water supply utilities face the requirements of

federal and state legislation regulating sources of supply and treatment. Coastal zone management has recognized that

many priority uses of the shorelines and near-shore areas are dependent on good water quality. Growth management

is an emerging concept, and concurrency of infrastructure improvements with development approvals highlights the issue

of deficient stormwater systems in many communities. Protection of endangered and threatened species, urban forestry,

and riparian corridor protection all have a relationship with stormwater management.

401
The Walls Will ComeTumbling Down (or at least they better)

The proliferation of federal, state, and local water resource (and related) regulations in recent years has created an

environment in which dispersed responsibility for water in various forms and for various purposes is rapidly becoming

unworkable. The institutional barriers that have been created over the past hundred years or so to focus attention, energy,

and responsibility no longer fit the public needs. As watershed-scale studies, planning efforts, and the concept of TMDLs

clearly illustrate, water resources are inextricably bound together regardless of their temporary form, use, and character.

The next decade will see accelerating consolidation of water resource management responsibilities at the local level

of government. This is contrary to the control interests of some individuals and entities, and will not happen silently or

easily. Will cities, counties, and special districts relinquish a little (or a lot) of their control over water resources through

interlocal agreements? Will they accept a regional entity for water supply, wastewatertreatment, stormwater management,

or even water quality? What will be the effect on stormwater utilities?

What are the organizational implications of the coming changes in storm water management? Realistically, local

governments change slowly. Public Works and Street Departments have historically been the lead organizations of storm

water programs, but they rarely have had much involvement in water quality issues. If storm water quality begins to

influence local priorities, it is more likely that water and wastewater utilities will assume storn water management

responsibilities from Public Works and Street Departments than the reverse. Public Works agencies will have to upgrade

their engineering and scientific capability or risk losing their storm water management role to water and wastewater utilities

that are typically well-established, well-funded, and well-understood by the public.

The Ability to innovate Will Exceed the Need

Most of the early stormwater utilities programs were rather narrowly focused, and the funding mechanisms supporting

them were relatively simple. In recent years, however, there has been a shift toward more sophisticated and complex

approaches to all aspects of stormwater management--from master planning to rate methodology design. Much of the

credit goes to the explosive growth in information processing capability associated with the computer revolution of the past

20 years. It is not clear, however, that much of the added capability to innovate is necessary to meet stormwater

management needs. This is not to suggest that opportunities to improve should be ignored simply because they are based

on increasing capability to do so. The following examples demonstrate how the ability to innovate in stormwater through

technology can run amok, and suggest how it should be managed to the benefit of people and the environment.

There is no substitute for understanding what is really important. One Southeastern United States city invested over

$1 million dollars assembling a highly detailed location inventory of its stormwater systems on a relatively sophisticated

data processing platform. Unfortunately, the need for the inventory was not premised on a clear program strategy, nor

was adequate funding available or established concurrently to support capital improvements or maintenance

enhancements that could be facilitated by the inventory. The local elected officials finally tired of the seemingly mindless

spending on the inventory and refused to discuss program improvements. Today, nearly 10 years later, the inventory has

not been maintained and is out of date, and few improvements have been made in the stormwater management program.

What is technically possible does not always make common sense, and what makes sense is not always technically

possible. A Northeastern city recognized that the stormwater component of its wastewater service fee rate methodology

(one that was based on water meter size and internalized within its water/wastewater rates) was not reasonably allocating

the cost of stormwater services and facilities across the community. Change to a more rational approach was desired,

so a thorough assessment of the range of options was undertaken. A broadly representative advisory committee aided

in the selection process. A relatively simple stormwater rate concept was selected that segregates stormwater funding

from wastewater and water service. It will allocate a portion of the cost of stormwater service on the basis of gross area

and a portion on the basis of impervious area. Once the impact of the change on certain rate payers was recognized,

however, the advisory committee decided that phasing in the new rate over three years was a better idea than making the

change in one step. While the technical support requirements of the phased approach are not especially demanding, the

public information and education challenge is enormous. Not only must the new rate methodology explained to the public;

it and the phase-in concept must be explained every year for three years.

402
Errors by a Few Will Make Life Miserable for Many

As the number of stormwater utilities grows, there is a natural tendency among municipal managers to assume that

the process and results have become standardized, and the experiences of another community can simply be transferred.

In an effort to save money, some cities and counties have established utilities without sufficient foundation and have even

adopted service fee ordinances without the benefit of a cost of service analysis or a rate study. Such misjudgments have

led to some monumental errors that have the potential to erode if not destroy the viability of the utility concept in a region,

a state, or even nationally.

One city recently established a stormwater utility and adopted rates based on internal analyses that did not define a

program, project the cost of service, or estimate the rate base available to generate revenue. As a result, the initial service

fee billing was for nearly three times as much total revenue as the administration had indicated it hoped to raise for

stormwater management. Furthermore, sufficient public information and education had not been conducted prior to the

initial billing, so the public did not understand the purpose of the billing. A lawsuit was filed, and a same judgement on

behalf of the plaintiff has resulted in the servie fees being rescinded and revenues returned with interest.

Expectations Will Advance Faster than Programs

One common experience of the cities and counties that have established stormwater utilities is that public expectations

for the program have exceeded the utility’s ability to perform. This means that creating accurate expectations before a

utility is established must be a high priority. One cause for unfulfilled expectations is that stormwater utility revenue

streams are usually insufficient to address all the accumulated problems in a relatively short time. Initial stormwater utility

service fees have typically been less than $3 month for single-family residences.

Perhaps more significant, however, is the fact that most stormwater utilities inherit programs and systems that are not

only deficient, but also do not offer an adequate foundation for a good, more comprehensive, program. Utilities often must

invest one to three years creating the foundation for the program before real results begin to emerge in the form of capital

improvements, remedial repairs, upgraded maintenance, and more effective regulations. Ratepayers tend to have little

patience, however, when they are writing checks regularly to a stormwater utility.

In the context of NPDES Phase II permits, public expectations of improvements in water quality need to reflect the

complexity of water quality issues and the limited ability of local government to quickly alter conditions in receiving waters

through informational and regulatory programs. Attempting to sell a utility to a community as a response to federal water

quality mandates has been unsuccessful in several communities. The public recognizes that stormwater quality, while

important, is still a minor part of the total cost of stormwater management. Unless a comprehensive quantity and quality

control program strategy is apparent, it is difficult to generate support for a stormwater utility.

403
Are Green Lots Worth More Than Brown Lots?

An Economic Incentive for Erosion Control on Residential Developments’

Martha Herzog and Jon Harbor

Department of Earth and Atmospheric Sciences

Purdue University

West Lafayette, Indiana 47937

Keith McClintock

Geauga Soil and Water Conservation District

Burton, Ohio 44021

John Law

Indiana Department of Natural Resources, and Saint Joseph Soil and Water Conservation District

South Bend. Indiana 46614

Kara Bennett

Departments of Statistics

Purdue University

West Lafayette, Indiana 47937

Abstract

Construction sites are major contributors to nonpoint source (NPS) pollution. However, a lack of personnel to enforce

erosion control regulations and limited voluntary compliance means that few developers apply effective erosion control.

New approaches are needed to increase erosion control on construction sites if this source of NPS pollution is to be

significantly reduced. We have tested whether an economic advantage exists for developers who use vegetative cover

for erosion control, independent of advantages gained in addressing environmental or regulatory concerns. Improving

residential lot appearance from muddy brown to green grass may increase the appeal of the lot to buyers. A market survey

shows that homebuyers and Realtors perceive vegetated lots to be worth more than unvegetated lots, and this increased

value exceeds the cost of seeding. Thus, developers can now be encouraged to invest in vegetative cover because of the

potentially high return on the investment.

Introduction

Sediment Pollution and Construction Sites

Nonpoint source (NPS) pollution, produced from diffuse sources such as runoff from agricultural land, construction

sites, and urban surfaces, is now the leading cause of surface waterqualitydegradation in the United States (Novotny and

Chesters, 1989; Federal Register, 1990). In developing areas, construction sites are a major source of NPS pollution

because soil erosion rates are increased dramatically when land is exposed and disturbed by excavation and vehicular

movement (Harbor et al., 1995; Goudie, 1994; Goldman et al., 1986, Fennessey and Jarrett, 1994). In fact, some of the

greatest soil erosion rates ever reported are associated with construction activities (Crawford and Lenat, 1989); erosion

rates on construction sites are typically 2-40,000 times greater than rates under preconstruction conditions (Wolman and

Schick, 1967; Harbor, in press). Sediment contributed to streams by construction sites can exceed that previously

’ This paper is reprinted from the Journal of Soil and Water Conservation, Spring Issue, 2000. We thank the Soil and Water Conservation Society for

their permission to reprint this article.

404
deposited over many decades under pre-development land uses, radically altering stream geomorphology and ecology

(e.g., Wolman and Schick, 1967). The larger-than-normal sediment deposition in waterways frequently exceeds the natural

capacity of the receiving water system to assimilate and equilibrate to the sediment influx (Paterson et al., 1993), causing

rapid channel changes and increased probability of flooding, erosion, and sedimentation problems (Goldman et al., 1986).

In addition to sediment, construction sites generate other pollutants such as pesticides, nitrogen, and phosphorus from

fertilizers, petroleum products such as oil and gas from machinery, soil stabilizers, construction chemicals, and washings

from concrete or bituminous mixing and flushing operations (Koehn and Rispoli, 1982; Lemly, 1982). In some cases these

pollutants are in particulate form or are adsorbed by soil particles and are transported with the suspended sediment in

runoff from construction sites (Paterson et al., 1993; Bhaduri et al., 1997).

Although construction sites generate a wide range of potential pollutants, sediment overshadows all the other

construction site pollutants in total ecological and economic impact on receiving waters (Lemly, 1982). It was estimated

that 15 million tons of sediment were released from urban construction sites to surface waters in or near heavily populated

areas in 1975 (Lemly, 1982). The North Carolina Department of Natural Resources and Community Development has

stated, that “sediment and its effects on stream environments” is the “most widespread water quality problem in North

Carolina” (Crawford and Lenat, 1989). Because construction activities predominantly occur near existing population

centers, the waters that are most seriously degraded are generally those that are most frequently used (Lemly, 1982).

Economic Consequences of Sedimentation

In addition to environmental impacts, enhanced delivery of sediment to off-site areas from construction activities has

significant economic effects (Table 1). These economic impacts result from lakes and streams becoming turbid and filling

with silt, destruction of commercial aquatic species, the need for additional treatment of turbid waterfor industrial use, filling

of harbors and navigation channels, loss of storage capacity of reservoirs, damage to drainage ditches, increased

frequency of flooding, loss of aesthetic value in the environment, and loss of game habitat (Lemly, 1982; Wolman and

Schick, 1967; Koehn and Rispoli, 1982). The economic burden of mitigating these environmental impacts is almost always

placed upon the taxpayer, rather than on the operator of the construction site that is producing high sediment yields

(Harbor, in press). By not paying to prevent the off-site transport of sediment through the use of erosion control measures,

the developer allows sediment from the construction site to reach waterways where the economic and environmental costs

of any impacts are paid by downstream landowners and the community as a whole, and not the developer.

Overall, annual expenditures for in-stream and off-stream impacts due to sedimentation in the United States exceeds

$11.6 billion (Table 1). In-stream effects include impacts while sediment is in a waterway (stream, river, lake, or reservoir).

Off-stream effects can occur before or after sediment reaches a waterway, either in floodwater or in water withdrawn from

waterways to be used for industries, municipalities, or agriculture (Clark, 1985; Clark et al., 1985; Paterson et al., 1993).

Although agricultural areas are far more extensive than construction sites, the mass of sediment per unit volume of runoff

from urban and construction areas is 5 to 20 times greater than that of runoff from agricultural lands (Fennessey and

Jarrett, 1994). In addition, construction sites are usually located in developing or developed areas, where potential impacts

on infrastructure and other water uses are more severe than in rural areas. Estimates of agriculture’s contribution to offsite effects range from l/3 to 2/3 of the total (Clark, 1985; Clark et al., 1985; Colacicco et al., 1989, Pimentel, et al. 1995).

Thus, urban off-site environmental impacts are probably on the order of $3.9 to $7.8 billion per year (l/3 to 2/3 of the total

off-site effects), and are often borne by off-site landowners and communities. One of the main goals of erosion and

sediment control regulations is to avoid these costs. The problem, however, is that developers have to pay to reduce

erosion yet do not see any immediate return on this investment. Because there is little economic incentive for developers

to control erosion, regulatory and educational approaches have been developed to improve construction site erosion

control, and requests to impose impact fees on developers have increased (Trotti, 1997).

405
Table 1. Off-site damage costs from soil erosion by water in the United States

Type of Damage

In-stream damage

Recreational (fishing, boating, swimming)

Water storage facilities (dredging, excavation, construction of sediment

pools)

Navigation (accidents, dredging)

Other in-stream uses (commercial fisheries)

Subtotal in-stream

cost

(millions in 1997 dollars*)

3,886.0

1,340.7

1,088.l

1,748.7

8,063.5

Off-stream effects

Flood damages (sediment damage to urban and agricultural areas)

Water conveyance facilities (sediment removal of drainage ditches and

irrigation canals)

Water treatment facilities

Other-off stream uses (municipal and industrial, steam electric power

plants, irrigation)

Subtotal off-stream

Total water erosion costs

(Data based on: Clark et al., 1985)

1,496.l

388.6

194.3

1,554.4

39633.4

11,696.9+

*Conversion using Consumer Price Index from 1980-1997.

+ Assuming that effects are the same today as in 1980.

Vegetation and erosion control

The significant ecological and economic impacts of sedimentation provide strong motivation for erosion control. Soil

erosion involves the detachment of soil particles by raindrop impact, wind-blown particle impact, wetting and drying cycles,

freezing and thawing, and runoff, and the transport of detached soil particles by rain splash, wind and runoff

(Ekwue, 1990; Goldman et al., 1986). Climate, topography, vegetative cover, and soil characteristics are the principal

factors that control soil erosion potential. Climate and soil characteristics cannot be readily controlled on a site, and

topography is constrained by pre-existing conditions and the grading plan, leaving surface cover as the most easily

modified variable that controls oil erosion on a site. Increasing vegetative cover on barren areas such as construction sites

is an excellent way to impede soil erosion and decrease sedimentation (Fig. 1).

“Vegetative cover is the most effective form of erosion control... a properly revegetated soil will be protected from

erosion indefinitely without any need for human attention” (Goldman et al., 1986, p. 6.23). Vegetation (especially close

to the ground surface) protects the surface from raindrop impact and reduces the velocity of water flowing over the surface

by increasing surface roughness and disrupting overland flow (Clark et al., 1985; Rogers and Schumm, 1991; Satterlund,

1972). The reduction of water velocity flowing over the surface and the breaking up of soil by plant roots increases the

amount of infiltration, thereby reducing the amount of surface water flow (Clark et al., 1985). Vegetation also depletes

subsurface water between rainfall events, which reduces the amount of runoff during storm events. In fact, vegetative

stabilization on construction sites has been shown to reduce soil loss by 80% (Harbor et al., 1995) to 99% as compared

to bare soil (Koehn and Rispoli, 1982). The cost of reducing soil erosion using vegetative cover depends on the materials

used, but typical temporary seeding on a one-third acre residential lot in the Midwestern US costs from $250 to $325.

Regulations requiring construction site erosion control

In the US, the biological and physical impacts of off-site sedimentation have prompted local, state, and federal

regulations requiring erosion and sediment control for construction sites. The National Pollution Discharge Elimination

System (NPDES) is a national program that issues, monitors and enforces permits for stormwater discharges associated

406
1000

r

----...-....~..- I 1

10 20 30 40 50

Vegetation Cover (%I

Figure 1. Sediment yields for different vegetative cover densities at 30, 60, 120, and 180 minutes of simulated rainfall on a 10% slope (Rogers and

Schumm, 1991).

with industrial activity such as construction underthe Clean Water Act (Federal Register, 1990). State and local regulators,

under the NPDES program, require erosion and sediment control for construction sites with 5 acres or more of land

disturbance (Federal Register, 1990). Because vegetative cover greatly reduces soil erosion, many federal and state

regulations, such as Rule 5 in Indiana and the Model Regulations for Urban Soil Sediment Pollution Control in Ohio,

encourage the use of surface cover as an important element of erosion control on construction sites.

In Indiana, for example, state regulations mandate that sediment should be contained on the construction site and not,

for example, allowed to run onto public or private roadways. Rule 5 requires that if vegetative practices such as seeding

and mulching are used, they must be implemented within seven days of the “last land-disturbing activity” at the site and

that these actions are the responsibility of the person in charge of the construction activity, which usually is the developer

(Indiana Department of Natural Resources, 1992). Similarly, in Ohio, Model Regulations for Urban Soil Sediment Pollution

Control (1980) require that the responsible party for the development stabilize denuded areas with permanent ortemporary

soil stabilization within seven days for any denuded area that has reached its final grade or is to remain dormant for more

than 45 days. The permanent vegetation is not “considered established until ground cover is achieved which.. .provides

adequate coverand is mature enough to control soil erosion satisfactorily and to survive adverse weatherconditions”(Ohio

Department of Natural Resources, 1980).

Enforcement of erosion control regulations varies significantly among states. For example, in Indiana, the Indiana

Department of Environmental Management (IDEM) controls permitting and enforcement, but local soil and water

conservation districts (SWCD) review and evaluate erosion control plans. At typical staffing levels, SWCDs in developing

areas find it very hard to keep up with the large number of developments they are responsible for. The local SWCDs

inspect the construction sites to establish whetherthe developer is implementing the soil erosion control plan correctly and

to observe whether the possibility of or the actual transport of sediment off-site exists. The SWCD will provide the

developer with written recommendations describing which erosion control measures need to be improved, maintained, or

installed. The developer then has two weeks to comply with the recommendations. If the developer is not found in

compliance with the requirements after recommendations have been made, the SWCD reports the site to the Urban

407
Erosion Control Specialist from the Indiana Department of Natural Resources (IDNR), who has been receiving copies of

all written warnings to the developer. The Urban Erosion Control Specialist will then visit the site and determine whether

the site should be reported to the IDEM. Subsequently, the IDEM determines whether further action, such as levying a

fine against the developer, is warranted. This process can lead to delays of many months between identification of a

problem and regulatory enforcement.

In reality, it takes a great deal of coercion to get developers to promptly apply erosion control measures on their sites.

Developers find applying erosion control measures inconvenient, costly, and time consuming, and are fully aware of the

lack of regulatory personnel to enforce local, state, and federal mandated erosion control (Harbor et al., 1995). Therefore,

developers often do not comply with the regulations and let their sites remain bare (Harbor, in press; Harbor et al., 1995).

When inspected, sites are often either lacking erosion control measures or maintenance of existing control measures is

long overdue. The effort (if any) on the developer’s part to maintain or implement the erosion control measures is often

inadequate and is done to appease the local SWCD, rather than with the goal of achieving ‘best management’ of the site.

Aside from regulation, there is little incentive for a developer to use erosion and sediment control practices. In fact, a

developer who uses erosion control may be at a cost disadvantage compared to other developers who do not, thereby

making construction less profitable (Harbor, in press).

Origin of this study

In a study evaluating the use of rapid seeding and mulching to reduce NPS pollution from construction sites, one

developer commented that he liked seeding because he thought that it made his developments more marketable (Harbor

et al., 1995). The developer soon began to include extensive seeding on his other developments to achieve the same

neat, green looking result. Even though the developer was interested in seeding because he thought it would give him

a competitive edge over other developers, he was voluntarily using vegetative erosion control (Harbor et al., 1995; Harbor,

in press). As similar anecdotal evidence accumulated, it seemed possible that a higher market value for a seeded site

might provide an incentive for voluntary erosion control. If an economic advantage can be established, then it may be

possible to persuade developers to use erosion control on the basis of a profit motive, where regulation and education have

proved ineffective. If widespread voluntary application can be achieved by this means of increased profitability, it will make

it easier to obtain compliance with erosion control programs and reduce the burden on regulators. Furthermore, and most

importantly, the NPS pollution load from construction sites would be reduced.

Methodology

We hypothesize that green, grassed lots are more attractive to buyers and therefore may be valued more highly and

sell faster than bare, dirt lots. There are several ways to test this hypothesis, with the most thorough being a detailed

tracking of the sales prices and sales timing of a large number of randomly selected treated and untreated control lots on

residential constructions sites throughout the US. In the absence of data to perform this type of highly detailed approach,

we undertook a pilot study using photos of treated and untreated lots in a market survey questionnaire aimed at

establishing whether lots with green vegetative cover are valued higher than barren ones by Realtors, developers, and

homebuyers. In the work reported here, however, we do not evaluate whether green, grassed lots sell faster than bare,

dirt lots.

Randomly selected lots in three residential housing developments in Ohio and Indiana were seeded and mulched.

Photographs of these lots were taken prior to seeding and then when the grass was approximately one inch high (Fig. 2).

Lots were photographed from three angles (front left, front center, and front right), and selected photos were used in a lot

valuation survey. The market survey was designed as a broad tool to investigate a wide range of factors which

homebuyers, Realtors, and developers find important when buying/selling a lot in a residential housing development. The

survey included open- and closed-ended questions, and those surveyed were not told the actual purpose of the survey.

The survey is reproduced in Herzog (1997). Included within the wide range of questions in the survey were specific

questions on the importance of lot appearance, and a lot valuation question in which those surveyed were asked to place

prices on lots shown in photographs. Those surveyed were told the lots were in the same neighborhood/subdivision, with

the streets and curbs installed and had the samesewer/septic system, water system, and noise level. They were then

408
Figure 2. Examples of grassed and bare lot photographs used in the survey.

given 10 lot photos and asked to establish prices for each lot, having been told that the average lot value in the

development was $20,000.

Most Realtors and developers were interviewed at their offices in St. Joseph County, Indiana and Geauga County,

Ohio. Potential homebuyers were interviewed either at a neutral location or at their place of work, and included residents

of St. Joseph County and West Lafayette, Indiana, as well as personnel at a chemical engineering facility in Buffalo, New

York which was relocating to Philadelphia, Pennsylvania. The survey typically took lo-20 minutes depending on the

responsiveness of the individual.

After completion of the surveys, comparative statistics were used on the lot valuation data to assess whether there

was any significant difference between “brown” and “green” lot values for Realtors, developers, and homebuyers. Analysis

of variance was initially used to be able to test for the existence of significant interaction between the fixed variables

(respondent group and color), while taking into account variation that occurs in the random variables (es., subjects). The

assumptions needed to appropriately apply this method, such as normality of the error terms, were found to be satisfied

(Montgomery, 1997).

409
+8OC

E

c

+4oc

i

$ Awag

.-

0

s

z

-400

2 -800

Price Differences for Green and Brown Lots

Results From a Lot Valuation Study

Figure 3. Differences in average prices for green and brown lots between survey groups.

Table 2. Effect of lot treatment on price for three different survey groups

Green Lot Brown Lot

Mean Price ($), Mean Price ($),

Price

Difference Test

Significance

Level

Group

Realtors

Homebuyers

Developers

sample size (n)

20.711

(r&155)

20,250

(n=36)

20,469

sample size (n)

19,967

(rk154)

19,500

(n=36)

20,218

c§)

744

Statistic

t=4.0085

(p-value)

0.0001

750 t= -1.7957 0.0788

251 t= -0.9200 0.3609

An important element of the economic analysis of lot greening is the actual cost involved in applying seed.

This can vary widely depending on the method used to apply the seed, and the density of vegetation desired. In

this work, we restrict the analysis to an amount and type of cover intended for erosion control, as opposed to grass

species and density intended for final lawn cover. For this study we used independent contractors to apply seed,

mulch, water and fertilizer by hydroseeding. Other common approaches include use of a hand seeder, and

mulching with straw either by hand or using a blower. During dry seasons in some areas, watering may be

necessary to produce successful germination and early growth. Thus there is a wide range of possible costs of

lot greening. In this study we use the actual cost of hydroseeding for our study sites in Indiana and Ohio, $300 per

lot, although we could have applied seed and mulch by hand for about $100 per lot. Readers may want to contact

their local Soil and Water Conservation District to get estimates of typical costs for their areas.

Results

A total of 478 lot valuations (310 by Realtors, 96 by developers, and 72 by homebuyers) were made.

However, during the survey process, it became apparent that two of the photographed lots were being ranked

either highest or lowest based on their specific background (one with a fire hydrant and another with lush tree

vegetation behind the lot giving an appearance of more privacy than the other lots). Lot valuations based on these

two photos, one green lot and one brown were eliminated prior to the statistical analysis.

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Initial statistical evaluation of the entire data set focused on determining if the data fit a model in which price

was a function of the overall mean price, effects related to the group, the individual surveyed, the individual lot and

the lot color plus interaction and random error terms. In this model we assume that the effect of the particular lot

and the particular individual are random variables that are independently and normally distributed with a mean of

zero, and also that the error terms are independently and identically distributed as normal random variables with

mean of zero and variance 02. Analysis of variance followed by a normal probability plot of the residuals, and

plotting of the residuals versus the predicted values, demonstrated that the error terms were normally distributed

with constant variance (Montgomery, 1997). This analysis also demonstrated that there appeared to be significant

differences in the variations of prices between groups, which complicates analysis of the data as a combined

group. Thus it was necessary to analyze each group separately, using at test to evaluate the overall effect of color

within each group.

The Realtors surveyed gave an average value of $20,711 on the green grassed lots and $19,969 on the brown

dirt lots. The distributions of lot values for green and brown lots were statistically significantly different at a 99.99%

confidence level (Fig. 3, Table 2). As a simple difference between means, the perceived added value for green

lots was $742 per lot.

Narrative questions on the survey revealed additional qualitative insight into Realtors’ perceptions of lot value,

and reasons for preferring green lots. One Realtor commented: “I don’t like these mud lots.” Others said the grass

was more appealing and “easier on the eye,” and that the lots look better because they are green. Other Realtors

did not see the importance of seeding and believed that grass should not enter into the decision because it will

be destroyed in the house building process. “Grass makes it look better but means nothing for what’s coming.”

Overall Realtors perceived that homebuyers would prefer the grassed lots (“I think people like grass,“) and

the green lots would sell first because the green grass will remind homebuyers of a yard and allow them to

visualize what a house and yard would look like on the lot. One Realtor stated that the grass/ground cover was

more appealing than dirt, and that homebuyers “wouldn’t like the bare ones very much.” Another noted that buyers

would be more willing to walk a grassed lot in inclement weather lot because the grass would absorb the moisture

and that buyer would not walk a dirt lot because it would become muddy and puddle. One Realtor stated: the

green lots look “lush and fertile;” some people cannot visualize dirt lots as possibly being lush and fertile. This

Realtor also brought up the concern that a buyer may ask about the drainage if the lot is wet, and if the dirt lot is

dry, caked, and cracked, the buyer will wonder if anything can grow on it.

Homebuyers

The homebuyers surveyed placed an average value of $20,250 for the green lots and $19,500 for the brown

lots. The distributions of lot values for green and brown lots were statistically significantly different at a 92%

confidence level (Fig. 3, Table 2). As a simple difference between means, the perceived added value for green

lots was $750 per lot. The added value of $750 (the greatest added value among the groups surveyed) is

particularly significant because homebuyers are the ones who actually pay for the lots.

Homebuyers stated that grass gives a realistic impression of the future appearance of the lot and it is more

appealing; and that the final product is more difficult to visualize on dirt lots. In general, the homebuyers

acknowledged that the grass looks good and has more appeal, while understanding that the lots would be

disturbed during construction. One homebuyer said that the green look was nicer but that it “wouldn’t effect my

decision to buy,” because grass was not a “big deal.” Even though comments such as these were made, on

average homebuyers valued green lots $750 more than brown lots.

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Developers

The developers surveyed placed an average value of $20,469 on the green lots and $20,219 on the brown

lots. The distributions of lot values for green and brown lots were statistically significantly different at only a

64% confidence level (Fig. 3, Table 2). Typically this would be viewed as indicating no statistically significant

difference. As a simple difference between means, the perceived value of the green lots was $250 greater

than the brown lots. Clearly, the small difference between the green and brown lots data sets and the

comparatively low significance level indicate that developers perceive little or no difference based on lot color.

During the survey, developers addressed the difference between the grass and dirt lots and stated that it

should not be a factor in lot price. They pointed out that the green lots will become brown lots during

construction and that the homebuyer will put in a yard anyway. Other developers saw that ground cover was

more attractive (“I like the green”) and perceived that homebuyers would like the grass. Also, some perceived

that the green look made a development more marketable compared to other developments; one developer

said he “greens up” his developments to make them look more attractive. Another stated that grass makes a

lot look like it has topsoil, and if there are soil concerns, the grass demonstrates that vegetation can be grown

and is holding soil. One developer remarked how ground cover may be important to homebuyers for more

than just appearance. He stated that grass cover is more significant when there is rolling ground because if

there is unseeded soil on an adjacent lot, the soil may erode onto the grassed property to the dismay of the

homeowner.

The Economic incentive

Although green lots may be priced higher than brown lots, this gross value is only significant if the price

differential exceeds the cost of seeding. The difference in value between grassed and bare lots compared to the

cost of seeding provides a measure of potential net economic benefit to the developer. In terms of a simple net

return on investment, seeding a lot provides potentially excellent return. Homebuyers valued grassed lots $750

more than brown lots, and as it cost $300 to seed a lot in this study, the developer stands to profit by $450 per lot,

which is a 150% return on the initial investment. The ability to more than double an initial investment should be

an attractive and sensible advantage for the developer, if the perceived value difference actually translates into

a sale price difference.

Present Limitations and Future Work

This pilot study is an initial step in developing information that can be used to persuade more developers to

make widespread use of vegetative cover, and other forms of environmental protection. The results of this pilot

study are most relevant in areas where climate conditions allow for relatively easy establishment of temporary

vegetative cover, and are not applicable to arid or semi arid areas. In addition, budget restrictions limited the scale

of the study. Although we collected 478 lot valuations from 62 respondents, a much larger study with respondents

from many areas of the United States would overcome a potential criticism that the current study only represents

conditions in a small portion of the Midwest. Developers are also more likely to notice results based on data

collected within their region, especially if these are coupled with regional demonstration projects. Thus, the next

logical step is to initiate a network of coordinated studies in regions experiencing rapid residential development.

This would provide for analysis on a national as well as a regional level, and for comparisons between regions.

An additional limitation of the results presented here is that they consider only perceived increase in lot values.

In actual sales transactions, buyers may not actually behave in the way they say they would on a survey. As a

linked project, it would be desirable to track actual sales histories (timing and pricing) to provide a more complete

picture of the actual economic impact of lot greening. Future research should include analysis of a large number

of real-world transactions for which lot condition is known. This could be based on a large-scale, long-term study

in which researchers intervene to change lot conditions on selected lots or developments. Alternatively, if some

412
landowners are convinced by the results of this study, the experiment might occur naturally in the marketplace as

the findings of our work are disseminated.

Further extension of the basic concept of examining the direct profitability of environmental protection is also

possible. We were recently contacted by a consultant who had heard of the lot valuation study, and wanted a

similar study performed on the increased value of lots next to ponds on developments. Although ponds are often

built for stormwater control, and also aid in reduction of nonpoint source pollution, they can also have considerable

aesthetic appeal. Thus, it would be potentially very useful to know what the return on investment on a pond is for

a new residential development, both in terms of the increased price of lots adjacent to the pond, as well as the

increase in average price in lots for the development as a whole because of the improved appearance of the

development.

Conclusions

Showing that erosion control may be profitable provides a new way to reach developers who have failed to

act on the logic that erosion control provides environmental protection and is required to comply with local, state

or federal erosion control regulations. Evaluating the cost of environmental damage is not only very difficult, but

also of little direct relevance to a developer who does not directly pay the cost of the damage. Land development

is a business, with profit as a leading motive, so appealing to increased profitability is one potentially effective way

to change behavior.

The pilot study described here indicates that vegetated lots are perceived to be more valuable and more

desirable by Realtors and homebuyers. Realtors perceived that vegetated lots are worth more than barren lots

(by $742). They also perceived that vegetated lots are worth more to homebuyers and that homebuyers would

be willing to pay more for grassed lots. Homebuyers also perceived grassed lots to be more valuable and put the

largest premium ($750) on the lots for all those surveyed. The added lot value is only significant if the price

differential exceeds the cost of seeding ($300), which was the case for Realtors and homebuyers by $417 and

$450, respectively. Developers valued the vegetated lots higher than non-vegetated lots by an average of $250,

but the difference was not statistically significant. Even if it were significant, this price differential is less than the

cost of seeding and indicates that developers perceive that seeding costs are greater than the benefits of

vegetation. This perception of a net cost associated with greening a lot is perhaps why the market has largely

failed to recognize this simple way to increase a property’s value. Some developers did recognize the visual

appeal of the grass and believed that a greened development would attract homebuyers more rapidly than a

development that appears unkempt. However, thevaluation study indicates that developers have not aligned their

perception of lot value with that of homebuyers.

An alternative way of interpreting the results is to consider the potential return on the investment in the

vegetative cover. For a $300 investment the developer can receive a return of $750, i.e. a 150% return on

investment. Such a rate of return is difficult to achieve in most conventional investments. Finally, price differential

is not the only economic benefit of lot greening; if lots sell faster because of greening, profits will increase because

of lower financing costs for capital invested in the development process. Further research is needed to clearly

define the value of this potential economic impact associated with lot greening. However, at this stage it is

possible to state that in addition to the environmental benefits, and regulatory requirements associated with using

vegetation for erosion control, there may be significant marketing and thus economic returns associated with lot

greening.

Education concerning the environmental benefits of erosion control, and enforcement of regulations have not

produced widespread, effective use of vegetative cover for erosion control. Because developers generally do not

perceive much incentive to vegetate their developments aside from complying with often-ineffective regulations,

they typically do not. Typically a developer who is using erosion control practices believes s/he is at a cost

disadvantage compared to other developers who are not, thereby making the developer following regulation

believe s/he will be less profitable. Furthermore, the developer does not directly pay for the mitigation of the

environmental impacts caused by the sediment leaving the site; it is the burden of the taxpayer instead. In this

413
study, we have demonstrated that vegetating a development may be a profitable investment. Appealing to the

profit motive will hopefully provide a way to generate widespread use of vegetative cover that also provides erosion

prevention on construction sites.

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