ENVIRONMENTAL ASSESSMENT (EA) 

EPA’S REISSUANCE OF THE NATIONAL 

POLLUTANT DISCHARGE ELIMITATION 

SYSTEM (NPDES) GENERAL PERMIT FOR 

DISCHARGES FROM CONSTRUCTION 

ACTIVITIES. 

DECEMBER 2011 

 
Construction and Development NPDES General Permit Environmental Assessment 

1 

Acronyms and Abbreviations

ACHP – Advisory Council on Historic Preservation 

ATS – Active Treatment Systems 

ATTAINS – Assessment TMDL Tracking and Implementation System 

AWWA – American Water Works Association 

BMP – Best Management Practices 

BOD – Biological Oxygen Demand 

C&D – Construction and Development 

cfs – cubic feet per second 

cm - centimeter 

CWA – Clean Water Act 

DO – Dissolved Oxygen 

EPA – Environmental Protection Agency 

ERF – Enhanced Reach File 

ft/s – feet per second 

g - Gram 

GIS – Geographic Information System 

HAB – Harmful Algal Bloom 

HUC – Hydrologic Unit Code 

kg/ha – Kilograms per hectare 

LC – Lethal Concentration 

m - Meter 

mgd – Millions of gallons per day 

μg/L – Micrograms per liter 

mg/L – Milligrams per liter 

mL/L – Milliliters per liter 

mm – Millimeter 

NHD – National Hydrogeography Dataset 

NID – National Inventory of Dams 

NLCD – National Land Cover Database 

NMFS – National Marine Fisheries Service 

NOAA – National Oceanic and Atmospheric Administration 

NPDES – National Pollutant Discharge Elimination System 

NRC – National Research Council 

NRCS – Natural Resource Conservation Service 

NRI – National Resources Inventory 

NTUs – Nephelometric Turbidity Units 

PAHs – Polycyclic Aromatic Hydrocarbons 

PTS – Passive Treatment Systems 

RESIS – Reservoir Sedimentation Survey Information System 

RF1 – Reach File Version 1.0 

SABS - Suspended and Bedded Sediments 

SAV – Submerged Aquatic Vegetation 

SDWIS – Safe Drinking Water Information System 

SPARROW – Spatially Referenced Regressions on Watershed Attributes 
Construction and Development NPDES General Permit Environmental Assessment 

2 

SSC – Suspended Sediment Concentration 

STORET – Storage and Retrieval data warehouse 

T&E – Threatened and Endangered 

TDS – Total Dissolved Solids 

TESS – Threatened and Endangered Species System database 

TMDL – Total Maximum Daily Load 

TN – Total Nitrogen 

TP – Total Phosphorus 

TSS – Total Suspended Solids 

U.S. OMB – United States Office of Management and Budget 

USACE – United States Army Corps of Engineers 

USDA – United Stated Department of Agriculture 

EPA – United States Environmental Protection Agency 

USFWS – United States Fish and Wildlife Service 

USGS – United States Geological Survey 

USLE – Universal Soil Loss Equation 

WATERS – Watershed Assessment Tracking & Environmental Results 

WQI – Water Quality Index 

WQL – Water Quality Ladder 

WTP – Willingness To Pay 

yd3 – cubic yard 

 
Construction and Development NPDES General Permit Environmental Assessment 

3 

TABLE OF CONTENTS

1.0 INTRODUCTION 7

 1.1 Background 7

 1.2 Summary of the Proposed Action 8

 1.2.1 Structure/Appearance of Permit 8

 1.2.2 Eligibility for Coverage 8

 1.2.3 Notification Changes 9

 1.2.4. Non-Numeric Requirement Changes 9

 1.3 Clean Water Act, NPDES General Permits, and Effluent Limitation Guidelines 10

 1.3.2 Definintion of New Source 12

 1.4 Purpose and Need for the Proposed Action 13

 1.5 Documents Incorporated by Reference 13

2.0 ALTERNATIVES 15

 2.1 Background 15

 2.2 Proposed Action and Alternatives Considered for Review 15

 2.2.1 No Action Alternative 15

 2.2.2 Proposed Action 17

 2.2.3 Description of the Proposed Action 18

 2.2.3.1 Non-numeric Effluent Limitations in the Proposed CGP 18

 2.2.3.1.2 Erosion and Sediment Control Requirements 18

 2.2.3.1.3 Stabilization Requirements 20

 2.2.3.1.4 Pollution Prevention Requirements 20

 2.2.3.1.5 Best Management Practices (BMPs) to Achieve Non-Numeric Effluent 

Limitations 21

 2.2.3.2 Water Quality-Based Effluent Limitations 24

 2.2.3.2.2. General Water Quality Based Effluent Limitations 24

 2.2.3.2.3 Water Quality Based Discharge Limitations for Impaired Waters 24

 2.2.3.2.4 Water Quality Based Discharge Limitations for Tier 2, 2.5, or 3 Waters 25

 2.2.3.3 Site Inspections and Corrective Actions 25

 2.2.3.4 Stormwater Pollution Prevention Plan (SWPP) Requirements 26

3.0 AFFECTED ENVIRONMENT 27

 3.1 Introduction 27
Construction and Development NPDES General Permit Environmental Assessment 

4 

 3.2 Physical Resources 27

 3.2.2 Water Resources 27

 3.2.2.1 Freshwater Ecosystems 28

 3.2.2.2 Marine Ecosystems 29

 3.2.2.3 Human Use 30

 3.3 Biological Resources 30

 3.3.1 Aquatic Vegetation and Wildlife Resources 30

 3.3.2 Terrestrial Vegetation and Wildlife Resources 32

 3.3.3 Threatened and Endangered Species 33

 3.4 Socioeconomic Resources 34

 3.4.1 Land Use 34

 3.4.2 Population and Housing 35

 3.4.3 Transportation 36

 3.4.5 Cultural Resources 36

 3.4.6 Recreation 37

4.0 ENVRIONMENTAL CONSEQUENCES 39

 4.1 Introduction 39

 4.2 Basis for Comparison of Alternatives, Approach to Alternatives Analysis 39

 4.2.1 Background on the C & D Rule 39

 4.2.2 Approach to Comparison of Alternatives 40

 4.3 Implementation of Best Management Practices 41

 4.3.1 Construction and Site Planning 42

 4.3.2 Erosion Control 43

 4.3.3 Runoff Control 46

 4.3.4 Sediment Control 47

 4.3.5 Good Housekeeping/Materials Management 52

 4.4 Physical Resources 52

 4.4.1 Earth Resources 52

 4.4.2 Water Resources 54

 4.4.2.1 Freshwater Ecosystems 55

 4.4.2.2 Water Quality Index 60

 4.4.2.3 Human Use 61
Construction and Development NPDES General Permit Environmental Assessment 

5 

 4.4.3 Cumulative Impacts 66

 4.5 Biological Resources 67

 4.5.1 Aquatic Vegetation and Wildlife Resources 68

 4.5.1.1 Primary Producers 68

 4.5.1.2 Aquatic Invertebrates 68

 4.5.1.3 Fishes 69

 4.5.2 Terrestrial Vegetation and Wildlife Resources 70

 4.5.3 Threatened and Endangered Species 70

 4.5.4 Terrestrial Impacts from the BMP Requirements 71

 4.5.5 Cumulative Impacts 72

 4.6 Socioeconomic Resources 73

 4.6.1 Land Use 74

 4.6.2 Water Resources Uses 75

 4.6.2.1 Water Quality Index 75

 4.6.2.2 Human Uses 75

 4.6.3 Population and Housing 79

 4.6.4 Demographics 80

 4.6.5 Cultural Resources 80

 4.6.6 Cumulative Impacts 80

5.0 Other Considerations 82

 5.1 Consistency with Other Federal, State, and Local Plans, Policies and Regulations 82

 5.1.1 Clean Water Act 401 Water Quality Certification by State Water Quality 

Agencies 82

 5.1.2 Endangered Species Act of 1973 82

 5.1.3 Section 106 of the National Historic Preservation Act 82

 5.1.4 Environmental Justice 83

6.0 References 84

APPENDIX A 91

 
Construction and Development NPDES General Permit Environmental Assessment 

6 

TABLES

Table 2-1. Projected Existing Source CGP-Covered Sites Over the Term of the Proposed 

CGP 

16

Table 2-2. Proposed CGP Erosion and Sediment Control Requirements 19

Table 3-1. Some Characteristic Differences between Lakes, Ponds, and Reservoirs 28

Table 3-2. Common Names of Prevalent Freshwater, Estuarine, and Saltwater Organisms 31

Table 3-3. Economic Contributions by Type of Fishing 37

Table 4-1. eNOI Statistics on C&D Industry Applications Under the Existing CGP 41

Table 4-2. Estimation Results for the SPARROW Suspended Sediment Model 57

Table 4-3. Baseline C&D Stormwater Loading Summary and Post-Compliance 

Reductions 

58

Table 4-4. Distribution of TSS Concentration based on SPARROW Output for RF1 

Reaches Receiving C&D Stormwater Discharges 

58

Table 4-5. Total RF1 Miles that Receive Direct C&D Loadings with Improvements in 

TSS Concentrations 

59

Table 4-6. Distribution of TN and TP Concentrations Based on SPARROW Output for 

RF1 Reaches Receiving Direct C&D Stormwater Discharges 

59

Table 4-7. Estimated Pre-Proposed CGP and Post-Proposed CGP Water Quality 

Improvements 

61

Table 4-8. Summary of Benefits from Reducing Sediment and Other Pollutants in 

Stormwater Discharges from C&D Sites 

62

Table 4-9. Annualized Navigable Waterway Dredging, Pre- and Post-CGP Issuance 64

Table 4-10. Estimated Sediment Removed by Reservoir Dredging Under the Baseline 

Scenario and Reductions Under Options 4 and Option 4, CGP-related 

65

Table 4-11. Drinking Water Turbidity Under the Baseline Scenario and Reduction of 

Drinking Water Turbidity Under Option 1 and Option 4 

66

Table 4-12. EPA Menu of Stormwater BMPs for Construction Activities and the Potential 

for BMP-Generated Environmental Impacts 

71

Table 4-13. Annualized Reductions in Navigable Waterways Dredging 76

Table 4-14. Annualized Reductions in Reservoir Dredging 77

Table 4-15. Annualized Reductions in Drinking Water Treatment Costs 78

Table 4-16. National Results from the MSA-Level Affordability Lowest New Home Price 

Analysis- Price and Household Affordability Effects 

79
Construction and Development NPDES General Permit Environmental Assessment 

7 

1. INTRODUCTION 

1.1 BACKGROUND 

Unmanaged stormwater discharges from construction activities can cause an array of physical, 

chemical and biological impacts. Pollutants discharged in runoff from construction sites include 

sediment, turbidity, and nutrients. All of these pollutants are important contributors to water quality 

impairment nationwide. Sediment, turbidity, and nutrients degrade aquatic ecosystem health, 

drinking water supplies, and surface water clarity. Sediment deposition also reduces water depth in 

lakes, reservoirs, and navigational channels, increasing the need for dredging. 

The United States Environmental Protection Agency (EPA) has regulated the discharge of 

pollutants from construction and development activities since November 16, 1990, when the 

Agency established permit application requirements for ‘‘storm water discharges associated with 

industrial activity.’’ EPA published a final Phase I regulation on September 29, 1990 (55 FR 

47990) that established permit application requirements for “large” construction sites whose 

activities, either individually or as part of a larger common plan of development or sale, disturb at 

least five acres of land and have point source discharges to waters of the US. Phase II of the 

stormwater program was published on December 8, 1999 and required NPDES permits for 

discharges from “small” construction sites whose activities, either individually or as part of a larger 

common plan of development or sale, disturb at least one acre, but less than five acres (64 FR 

68722). 

Beginning in 1998, EPA has issued a series of National Pollutant Discharge Elimination System 

(NPDES) general permits covering stormwater from construction and development activities 

(“construction general permits,” or CGPs) for areas where EPA is the NPDES permitting authority. 

EPA reissued the CGP in 2003 and 2008. EPA is re-issuing its CGP to become effective upon 

expiration of the existing 2008 CGP. Effluent limitations included in the 1998 through 2008 CGPs 

have been issued based on EPA’s Best Professional Judgment (BPJ), which EPA can use as the 

basis for setting effluent limitations in cases where national, technology-based effluent limitation 

guidelines (ELGs) have not been promulgated. However, for the upcoming permit, EPA will be 

required to incorporate effluent limitations, including new source performance standards (NSPS), 

that are consistent with the Agency’s final ELGs (74 FR 62995) for the Construction and 

Development Industry Point Source Category (the “C&D Rule”), which were promulgated on 

December 1, 2009, the upcoming CGP will be required to include the C&D rule requirements. The 

C&D Rule included a regulatory definition of “new source” and developed effluent limitations for 

new sources (New Source Performance Standards, or NSPS). 

Issuance of a “new source” NPDES permit under Section 402 of the Clean Water Act (CWA) is 

considered a “federal action” that is subject to the National Environmental Policy Act (NEPA), and 

EPA regulations at 40 CFR 122.29(c) specify that the issuance of a NPDES permit for a new source 

is subject to the review provisions under NEPA as set forth at 40 CFR Part 6. 
Construction and Development NPDES General Permit Environmental Assessment 

8 

1.2 SUMMARY OF THE PROPOSED ACTION 

The Proposed Action is EPA’s issuance of the 2012 CGP. Like previous versions of the CGP, the 

permit will authorize the discharge of pollutants in stormwater from new and existing sources 

associated with construction sites greater than one acre where EPA is the permitting authority. 

EPA’s existing 2008 CGP became effective on June 30, 2008 (see 74 FR 40338), and will expire on 

February 15, 2012. The 2012 CGP will replace the 2008 CGP as well as the 2003 CGP for 

construction sites covered under the administratively continued permit. 

The proposed new CGP incorporates the requirements of the final C&D rule in addition to 

clarifying a number of administrative, procedural, and technical requirements that are carried 

forward from the 2008 CGP. The proposed CGP closed for public comment on July 11, 2011. 

A summary of the major changes in the proposed 2012 permit, compared to the 2008 CGP, are as 

follows. 

1.2.1 STRUCTURE/APPEARANCE OF PERMIT

EPA attempted to restructure its CGP so that it would be better organized to present requirements in 

a generally more readable manner. It is EPA’s hope that this structure will enhance the permittees’ 

understanding of and compliance with the permit’s requirements. For instance, the permit’s 

stormwater control requirements are organized into distinct and related categories, such as erosion 

and sediment control requirements, stabilization requirements, and pollution prevention 

requirements. 

1.2.2 ELIGIBILITY FOR COVERAGE

Geographic Coverage of the Proposed Permit. Changes to the permit’s area of coverage consists 

of: Indian Country lands in EPA Region 4 and Denali National Park and Preserve (EPA Region 10) 

will be added to the proposed permit’s area of coverage and construction sites within the State of 

Alaska will no longer be covered under EPA’s CGP due to the authorization of the State NPDES 

program. 

Categories of Facilities That Can Be Covered Under This Permit. The proposed permit will 

authorize stormwater discharges associated with construction sites located in the coverage area of 

the permit that disturb one or more acres of land, or will disturb less than one acre, but are part of a 

common plan of development or sale that will ultimately disturb one acre or more. Eligibility for 

coverage by the permit is available to the following: 

 New projects 

 Existing projects 

 New operators of new or existing projects, and 

 Operators of emergency-related projects. 

Eligibility for Emergency-Related Construction. The proposed permit would provide immediate 

authorization for construction activities required for response to public emergencies (e.g., natural 

disasters such as a tornado or hurricane, widespread disruptions in essential public services). 

Immediate authorization will enable work that is necessary to avoid imminent endangerment to 

human health, public safety, or the environment, or to reestablish essential public services, to 
Construction and Development NPDES General Permit Environmental Assessment 

9 

proceed without administrative delay. The construction operator would still need to comply with 

the terms of the permit, and must submit an NOI and develop a stormwater pollution prevention 

plan (SWPPP) within a set period of time after commencing earth-disturbing activities, whereas 

typically operators are required to submit NOIs prior to commencing earth-disturbing activities. 

Treatment Chemicals . Treatment chemicals must be used in conjunction with conventional 

erosion and sediment controls to minimize reliance on its use. Options for the use of cationic 

treatment chemicals under the CGP were considered such as requiring an individual permit, or 

including additional, site-specific controls that may apply. In the proposed permit, EPA 

contemplates prohibiting the discharge of cationic chemicals, establishing maximum dosage rates, 

and, if the operator intends to use chitosan, residual testing requirements. EPA could provide 

coverage under the CGP for the use of cationic treatment chemicals, or, if it was determined that 

site-specific considerations and the toxicity concerns associated with some polymers warrant, the 

Agency could require coverage under an individual NPDES permit. Under either the CGP or an 

individual permit, EPA anticipates that the requirements affecting the use and storage of cationic 

treatment chemicals would be the same.

1.2.3 NOTIFICATION CHANGES 

Authorization Process/ Notice of Intents (NOIs). EPA proposes to increase the “waiting period” 

for construction site operators seeking coverage under this permit. The new timeframe is intended 

to better reflect the endangered species-related reviews that must take place prior to authorization. 

EPA is also hoping to maximize the use of its electronic NOI, or eNOI, process for authorizing 

construction discharges by requiring that construction operators seek coverage using the eNOI 

system. Certain case-by-case exceptions, i.e., instances in which a “paper NOI” will be allowed, 

will still exist, but approval by the applicable EPA Region will be necessary first. 

Notice of Termination. The proposed permit consists of additional requirements that affect 

termination of coverage under the CGP beyond site stabilization, such as removal of temporary 

stormwater controls and construction materials, waste, and waste handling devices. 

1.2.4 NON-NUMERIC REQUIREMENTS CHANGES

Sediment and Erosion Controls. The proposed permit includes specific requirements that 

implement the C&D rule’s sediment and erosion control limits. While many of these requirements 

are already included in the 2008 CGP, the proposed permit includes more detail in order to properly 

implement the C&D rule. The proposed permit has specific requirements that implement the C&D 

rule’s sediment and erosion control limits. While many of these requirements are in the 2008 CGP, 

the proposed permit provides additional specifics to properly implement the C&D rule. The most 

significant requirements in the renewed 2012 CGP will be: 

 Installation of vegetative buffers or equivalent controls, 

 Installation of sediment controls prior to earth-disturbing activities, 

 General maintenance requirements 

 Perimeter controls, 

 Exit point stabilization, 
Construction and Development NPDES General Permit Environmental Assessment 

10 

 Storm drain inlet control installation and maintenance, 

 Additional requirements for use of chemical treatments, and 

 Dewatering practice controls and discharge restrictions. 

Stabilization Requirements. The proposed permit modifies stabilization requirements that define 

more specifically EPA’s criteria for temporary and final vegetative and non-vegetative stabilization. 

Pollution Prevention. Beyond the C&D rule requirements for pollution prevention and the 

prohibition of certain discharges, the proposed permit contains specific control requirements that 

ensure pollutant dischargers are eliminated or minimized. The pollution prevention requirements 

restrict the discharge of fertilizers at construction sites. 

Water Quality-Based Effluent Limits. The proposed permit specifies additional requirements that 

apply to sites discharging to waters impaired for pollutants commonly associated with construction 

activities, such as sediment and nutrients. Additional requirements include tighter stabilization 

deadlines and more frequent site inspections. The proposed permit also includes additional 

requirements for waters identified as Tier 2, Tier 2.5, or Tier 3 for antidegradation purposes. 

Site Inspections. EPA proposes to explicitly require operators to visually assess the quality of the 

discharge if the site inspection occurs during a discharge-generating rain event (e.g. color, odor, 

floating, settled, or suspended solids). EPA also proposes to modify the storm size that triggers site 

inspections for those sites that elect to conduct inspections on a bi-weekly basis from 0.5 inches to 

0.25 inches. 

Corrective Actions. Although the 2008 CGP required corrective action, it did not include specific 

requirements instructing the permittee as to what conditions trigger specific corrective actions and 

what deadlines apply. The proposed permit specifies triggering conditions for corrective action, 

deadlines for such corrective actions, and documentation of what corrective action(s) were 

performed. 

Stormwater Pollution Prevention Plans (SWPPP). The SWPPP requirements are modified in 

accordance with the changes discussed above. In general, the requirements are more specific, but 

consistent with the 2008 CGP. 

1.3 CLEAN WATER ACT, NPDES GENERAL PERMITS, AND EFFLUENT 

LIMITATION GUIDELINES 

Section 301 of the Clean Water Act (CWA) provides that the discharge of pollutants is unlawful 

except in accordance with an NPDES permit. The Water Quality Act of 1987 added a section to the 

CWA that directed EPA to develop a phased approach to regulate stormwater discharges under the 

NPDES program. EPA published its final Phase I regulation on November 16, 1990 (55 FR 47990) 

that established permit application requirements for ‘‘storm water discharges associated with 

industrial activity.’’ 

EPA comprehensively defined “industrial activity,” which covered discharges from “construction 

activity,” including clearing, grading, or excavating. Phase I regulated “large” construction activity, 

covering activities that, either individually or as part of a larger common plan of development or 

sale, disturb at least five acres of land and have point source discharges to waters of the US. Phase 
Construction and Development NPDES General Permit Environmental Assessment 

11 

II of the stormwater program was published on December 8, 1999 and required NPDES permits for 

discharges from “small” construction sites, including activities that, either individually or as part of 

a larger common plan of development or sale, disturb at least one acre, but less than five acres (64 

FR 68722). 

The vast majority of stormwater discharges associated with construction activity are covered under 

NPDES general permits. EPA’s regulations authorize the issuance of general permits to categories 

of related discharges, such as discharges from the same type of source in a common geographic area 

(40 CFR 122.28). EPA, states, and tribes use general permits to cover a group of similar dischargers 

under one permit. General permits simplify the process for dischargers to obtain authorization to 

discharge, provide permit requirements for any discharger that files a Notice of Intent (NOI) to be 

covered, and reduce the administrative workload for NPDES permitting authorities. General 

permits, including the fact sheet describing the rationale for permit conditions, are issued by 

NPDES permitting authorities after considering public comments on the draft permit. 

Typically, to obtain authorization to discharge under a construction general permit, a discharger (the 

owner or operator of the construction site, usually a developer, builder, or contractor) submits to the 

permitting authority an NOI to be covered under the general permit. By submitting the NOI, the 

discharger certifies that it is eligible for coverage under the general permit and that it agrees to the 

effluent limitations and other conditions in the published general permit. 

For background, the first NPDES “construction general permit” (CGP) was issued by EPA in 

February 1998 (63 FR 7858; EPA Region 6 issued their final CGP in July 1998, 63 FR 36490). 

Upon expiration, the “1998 CGP” was replaced by a single, five-year national1

 CGP, published 

final in July 2003 (68 FR 39087). The 2003 CGP made a number of administrative, technical, and 

procedural changes to the 1998 permit and incorporated comments received on the draft CGP, 

published in December 2002. The 2003 CGP expired on June 30, 2008 and was replaced with the 

2008 CGP, which was issued for a 2-year term and included provisions that were substantially 

similar to the 2003 CGP. The 2-year 2008 CGP was subsequently extended to February 15, 20122) 

that included primarily administrative and procedural changes to the 2003 CGP. The 1998, 2003, 

and 2008 CGPs regulated stormwater discharges from construction activities primarily through 

“Best Management Practices” (BMPs) and non-numeric effluent limitations. These permit terms 

and conditions were based on EPA’s Best Professional Judgment (BPJ), which EPA can use as the 

basis for setting effluent limitations in cases where national, technology-based effluent limitation 

guidelines (ELGs) have not been promulgated. 

NPDES regulations require an NPDES permitting authority (either EPA or a delegated state 

NPDES program) to incorporate any newly promulgated ELG into applicable NPDES permits. EPA 

published its final C&D Rule (74 FR 62995) on December 1, 2009. ELGs can include several 

different types of technology-based pollution control, based on the type of pollutant, the type of 

source of the discharge, and level of control required by the CWA. The highest level of technology-

 

1

 EPA’s CGP provides coverage to areas of the country where EPA is the permitting authority. In the past, 

EPA Region 4 issued its own CGP, but starting with the new CGP, Region 4 areas will be covered under that 

permit. 

2

 On January 28, 2010, EPA extended the term of the 2008 CGP from June 30, 2010 to June 30, 2011 (75 FR 

4554). EPA extended the 2008 CGP to expire on February 15, 2012 to provide the Agency adequate time to 

finalize the new CGP. 
Construction and Development NPDES General Permit Environmental Assessment 

12 

based pollution controls are Best Available Technology (BAT) for existing sources and a New 

Source Performance Standard (NSPS) for new sources. NSPS can be the most stringent because the 

costs of retrofits are greater than the costs of new installations — pollution control technology that 

may be too expensive to install in existing sources can be cost-effectively installed in new sources. 

The C&D rule included BMPs covering erosion and sediment control measures and pollution 

prevention practices covering stormwater discharges from construction sites that commenced 

construction after February 1, 2010, which is the date upon which the C&D rule became effective. 

In addition, the C&D rule promulgated a requirement for larger construction sites to meet a numeric 

turbidity limit, effective August 2011 for sites disturbing 20 acres or more at a time, and February 

2014 for sites disturbing 10 acres or more at a time. 

Subsequent to the promulgation of the C&D rule, EPA received petitions for reconsideration of the 

numeric turbidity limit, which identified a potential error in its calculation. EPA re-examined the 

data and concluded that it had improperly interpreted the data upon which the numeric limit was 

based. In January 2011, EPA stayed the provisions of the C&D rule related to the numeric 

limitation and associated monitoring requirements until the Agency has completed a new 

rulemaking to correct the numeric limitation on turbidity. EPA plans to issue a corrected turbidity 

limit in a future rulemaking. 

The proposed permit is directly affected by the stay. EPA’s proposed permit indicates that if the 

numeric limit was finalized prior to the issuance of the final CGP, the limit will be included along 

with associated monitoring and reporting provisions. Because EPA is still in the process of 

collecting data to support the recalculation of the numeric turbidity limit, and therefore it appears 

that a final numeric turbidity limit will not be available in time to implement in the final permit, it is 

unlikely that EPA will include a numeric limit and related monitoring and reporting requirements in 

the final permit. EPA has proposed, however, to implement the remaining portion of the C&D rule 

that were not affected by the stay of the numeric limit. Based on public comments on the draft 

permit, EPA made changes to the proposed permit. 

1.3.2 DEFINITION OF NEW SOURCE

The regulations in 40 CFR Part 122.2 define “new source” as follows: 

New Source means any building, structure, facility or installation from which there is or 

may be a ‘discharge of pollutants,’ the construction of which is commenced: 

(a) After promulgation of standards of performance under section 306 of CWA which are 

applicable to such sources, or 

After proposal of standards of performance in accordance with section 306 of CWA 

which are applicable to such source, but only if the standards are promulgated in 

accordance with section 306 within 120 days of their proposal. 

The regulations at 40 CFR 122.29(b)(4) define what constitutes “construction” of a new source, 

stating that: 

Construction has commenced if the owner or operator has: 

(b)(i) Begun, or caused to begin as part of a continuous on site construction program: 

(A) Any placement assembly, or installation of facilities or equipment; or 

(B) Significant site preparation work; or 
Construction and Development NPDES General Permit Environmental Assessment 

13 

(b)(ii) Entered into a binding contractual obligation for the purchase of facilities or 

equipment intended to be used in its operation with a reasonable time. 

EPA also has the authority to provide specialized definitions of “new source” to particular point 

source categories (40 CFR 122.29(b) and 401.10). 

NSPS for the C&D point source category were promulgated in the final C&D Rule on December 1, 

2009. EPA defined a new source as “any source, whose discharges are defined in 40 CFR 

122.26(b)(14)(x) and 40 CFR 122.26 (b)(15) that commences construction activity after the 

effective date of this rule.” Under this definition, the only construction sites that are not “new 

sources” are those sites that commenced construction activity before the effective date of the final 

rule, which was 60 days after promulgation, or February 1, 2010. The proposed permit incorporates 

this definition of new source: 

“New source – a construction project that commenced construction activities after February 1, 

2010, and that requires NPDES permit coverage for its construction discharges under Part 1.2 [of 

the CGP].”

1.4 PURPOSE AND NEED FOR THE PROPOSED ACTION 

The purpose of the proposed action — the issuance of the NPDES general permit for stormwater 

discharges associated with construction sites greater than an acre where EPA is the permitting 

authority (the construction general permit, or CGP) — is to replace the existing NPDES general 

permit whose limits, terms, and conditions are based on BPJ effluent limitations with a new permit 

that is based on BAT-based effluent limits that are consistent with the C&D rule requirements for 

new and existing sources. The proposed action is needed because under NPDES regulations, EPA is 

required to incorporate technology-based effluent limitation guidelines (ELGs) into NPDES permits 

upon their promulgation. The existing permit was issued in 2008; since its issuance, final BAT and 

NSPS ELGs covering construction and development activities were published in 2009. 

Consequently, EPA must incorporate these new requirements into the CGP. 

1.5 DOCUMENTS INCORPORATED BY REFERENCE 

Documents that are incorporated by reference include the three major technical support documents 

for the C&D Rule; the Preamble and Proposed New CGP and the Fact Sheet to the Proposed new 

CGP; and the technical support documents for the revision to the numeric limit for final BAT and 

NSPS ELGs, the Preamble to the revised numeric limits, and the final numeric ELGs for C&D 

operations. Throughout this EA these documents are referenced as follows: 

EPA 2009a. Development Document for Proposed Effluent Guidelines and Standards for the 

Construction and Development Category. November 2009. EPA-821-R-08-007. 

EPA 2009b. Environmental Impact and Benefits Assessment for Final Effluent Guidelines and 

Standards for the Construction and Development Category. November 2009. EPA-821-R09-012 

EPA 2009c. Economic Analysis of Proposed Effluent Guidelines and Standards for the 

Construction & Development Industry. November 23, 2009. EPA-821-R-08-008. 

EPA 2011a. CGP 

EPA 2011b. CGP Fact Sheet 
Construction and Development NPDES General Permit Environmental Assessment 

14 

EPA 2011c. Final BAT and NSPS Numeric Effluent Limitation Guidelines for the Construction 

and Development Industry Point Source Category 

 

 
Construction and Development NPDES General Permit Environmental Assessment 

15 

2. ALTERNATIVES 

2.1 BACKGROUND 

Congress passed the Federal Water Pollution Control Act of 1972, or Clean Water Act (CWA) with 

the stated objectives of restoring and maintaining the chemical, physical, and biological integrity of 

the Nation's waters [33 USC 1251(a)] and of attaining ‘water quality which provides for the 

protection and propagation of fish, shellfish and wildlife [33 USC 1251(a)(2)]. The CWA provides 

that “the discharge of any pollutant by any person shall be unlawful” except in compliance with 

other provisions of the statute [CWA Section 301(a)]. EPA is authorized under the CWA to control 

discharges through the issuance of NPDES permits. 

NPDES permits are required under Section 402(a)(1) of the CWA to include conditions for meeting 

technology-based effluent limits established under CWA Section 301 and where applicable, under 

Section 306. When technology-based effluent limitations guidelines (ELGs) or new source 

performance standards (NSPS) are promulgated, EPA must incorporate these technology-based 

limits into applicable NPDES permits [40 CFR 122.44(a)(1)]. Prior to promulgation of final ELGs 

or NSPS, permitting authorities base technology-based effluent limitations on best professional 

judgment (BPJ) [CWA Section 402(a)(1)(B); 40 CFR 125.3(a)(2)(ii)(B)]. Where technology-based 

effluent limitations are insufficient for the discharge to meet applicable water quality standards, 

NPDES permits must also contain water quality-based effluent limitations as necessary to meet 

those standards. 

The technology-based effluent limits in the existing 2008 CGP are based on EPA’s BPJ since, at the 

time of permit issuance, the C&D Rule had not been promulgated. However in December of 2009, 

EPA promulgated final ELGs and NSPS covering the construction and development industry, 

which included a numeric effluent limitation for turbidity and defined the effective date of NSPSs 

as February 1, 2010. Upon promulgation of the final C&D Rule, all subsequent NPDES permits 

must incorporate these technology based limitations and standards. Thus, the proposed CGP 

includes the limitations of the C&D Rule to comply with the CWA and NPDES regulations.3

 

2.2 PROPOSED ACTION AND ALTERNATIVES CONSIDERED FOR REVIEW 

The purpose of this Environmental Assessment (EA) is to analyze, document and make public the 

potential direct, indirect, and cumulative environmental impacts that may arise from the 

implementation of the Proposed Action or the No Action alternative considered by EPA in the 

issuance of a new source NPDES general permit. The scope of this EA is limited to the 

environmental resources that may be affected by the No Action Alternative or the Proposed Action. 

Thus, the scope of this EA is limited both geographically to those coverage areas specified in the 

CGP (i.e., in which EPA is the permitting authority for the stormwater general permit), and 

categorically to cover only new sources. 

2.2.1 NO ACTION ALTERNATIVE: NO NPDES CONSTRUCTION GENERAL PERMIT 

ISSUED

 

3

 One provision in the C&D Rule — the numeric standard for turbidity — has been stayed 

following judicial review. EPA is currently in the process of collecting data to recalculate a new 

numeric standard. 
Construction and Development NPDES General Permit Environmental Assessment 

16 

The “No Action” alternative would be to not issue a general permit to replace the expiring CGP. 

Normally, in a case such as this, the Agency uses its authority under the NPDES regulations to 

administratively continue the existing permit. Permittees that have coverage under a valid NPDES 

permit at the time of its expiration may maintain their authorization to discharge under the terms 

and conditions of the expired permit. This authority to administratively continue NPDES permits 

works satisfactorily for permittees who have continuing operations at a defined location or within a 

defined area. However, the authorization to continue to discharge will not extend to facilities or 

operations that were not covered at the time the valid permit expired. Therefore, only stormwater 

discharges at C&D sites that were covered under the 2008 CGP as of midnight, February 15, 2012 

would continue to be covered until site activities are terminated, at which time their authorization to 

discharge under the 2008 CGP would also be terminated. Any stormwater discharges at C&D sites 

that are not covered as of midnight, February 15, 2012 will require coverage under another NPDES 

permit. 

The C&D Rule has established C&D activity commencing after February 11, 2010 as a new source. 

Unlike most operations covered under NPDES permits, which are generally continuing operations 

at a single site or within a defined circumscribed area, C&D activities are generally relatively shortlived (less than a year). As site operations that began prior to February 11, 2010 and are still 

ongoing become completed, the number of C&D operations considered existing sources will 

continue to diminish. EPA’s NOI data for C&D activities indicate that sites considered “existing 

sources,” (i.e., those where site activity began prior to the February 11, 2010 new source effective 

date, is covered under the existing CGP, and for which coverage is scheduled to expire after the 

anticipated effective date of the proposed CGP of February 15, 2012) will start small and diminish 

rapidly. At the end of the first year of the proposed CGP, the number of existing sources is 

projected to constitute 3% to 5% of annual CGP activity; by the expiration of the proposed permit, 

less than 1% of annual CGP activity will be existing sources (Table 2-1) 

Table 2-1. Projected Existing Source CGP-Covered Sites Over the Term of the 

 Proposed CGP 

Year Projected Number 

of Existing Sources (a) 

Low Activity 

Projection (b) 

Mean Activity 

Projection 

High Activity 

Projection 

2013 286 8% 5% 4%

2014 193 5% 3% 3%

2015 109 3% 2% 1%

2016 65 2% 1% 1%

2017 50 1% 1% 1%

(a) Based on data retrieved from EPA’s NOI database on May 23, 2011; sites whose coverage began 

prior to 02/11/10 and scheduled to expire after 02/15/12. 

(b) Based on data retrieved from EPA’s NOI database on May 23, 2011; the low activity projection is 

the minimum annual number of CGP covered sites from 2004 through 2011 (2011, estimated at 

3,800); the mean activity projection of 5,846 CGP covered sites is based on the annual number of 

covered sites from 2004 through 2010 and the estimated number for 2011; the high activity 

projection is the maximum annual number of 7,316 CGP covered based on the annual number of 

covered sites from 2004 through 2010 and the estimated number for 2011 

Thus, by January 31, 2012, nearly all C&D activities would be ineligible for coverage under an 

administratively continued 2008 CGP, meaning that operators at virtually all C&D sites would be 

required to apply for coverage under individual NPDES permits. Based on data from 2004 through 

2011, the No Action Alternative would result in submission of approximately 4,000 to 7,000 
Construction and Development NPDES General Permit Environmental Assessment 

17 

individual permit applications annually. These individual permits would include essentially the 

same terms, conditions, and limitations found in the proposed CGP as discussed under the Proposed 

Action. Thus, the environmental benefits and costs to the regulated industry would not be 

improved under this alternative. However, the increased effort and uncertainties of this alternative 

on the part of both the C&D industry and EPA would be enormous, especially because at present, 

EPA’s NOI website is processing the thousands of annual notifications efficiently. The industry 

would need to commit far greater resources to preparing applications, and EPA would need to 

commit far greater resources to reviewing these applications, preparing and publishing draft permits 

for public review and comment, and responding to comments before issuing final individual 

permits. Industry would have no clear idea of when their permits would be finalized, and project 

schedules would be at considerable risk. 

Hypothetically, a potential benefit under an individual permit program would be the increased 

opportunity for public review and comment for each permitted site. EPA believes, however, that 

any advantage to the public resulting from individualized public and comment opportunities would 

be outweighed by the negative impacts that would result from the delays in the permitting process 

that EPA anticipates would result. Based on the above discussion of the additional administrative 

burden and lack of additional environmental benefit, the alternative of not issuing the CGP would 

render the permitting of construction sites impracticable. 

EPA provided for notice and comment for the proposed CGP issued on April 25, 2011. Therefore, 

the public is already given a substantive opportunity to provide comments on the draft permit 

conditions that will be required of construction sites, which is similar to the type of opportunity 

they would have under an individual permit. The effluent limits in the permit, based as they are on 

the C&D Rule requirements, have also been subject to prior notice and comment during the 

promulgation of the C&D Rule. After the general permit is issued, the public can track the 

coverage of individual sites by monitoring the electronic Notice of Intent (eNOI) website and have 

the ability during the authorization waiting period to provide comments to EPA for consideration. 

2.2.2 PROPOSED ACTION: ISSUE A REVISED NPDES GENERAL PERMIT

The Alternative of issuing a revised CGP that incorporates the requirements of the C&D Rule 

complies with the statutory requirements of the CWA and the requirements of the NPDES 

regulations. The Agency has promulgated final ELGs and NSPS for the Construction and 

Development Industry Point Source Category in the C&D Rule. Therefore, EPA must incorporate 

the requirements of the C&D Rule4

 into any issued permit covering C&D activities where EPA is 

the permitting authority. This includes four states (Idaho, Massachusetts, New Hampshire, and 

New Mexico), the District of Columbia, Puerto Rico, all other U.S. territories with the exception of 

the Virgin Islands, federal facilities in four states (Colorado, Delaware, Vermont, and Washington), 

 

4

 EPA’s proposed permit indicates that if the numeric limit was finalized prior to the issuance of the 

final CGP, the limit will be included along with associated monitoring and reporting provisions. 

Because EPA is still in the process of collecting data to support the recalculation of the numeric 

turbidity limit, and therefore it appears that a final numeric turbidity limit will not be available in 

time to implement in the final permit, it is unlikely that EPA will include a numeric limit and 

related monitoring and reporting requirements in the final permit. 
Construction and Development NPDES General Permit Environmental Assessment 

18 

most Indian lands and a couple of other specifically designated activities in specific states (e.g., oil 

and gas activities in Texas and Oklahoma). This requirement also applies to any permit issued by a 

state with delegated general permit authority for an NPDES permit program. 

2.2.3 DESCRIPTION OF THE PROPOSED ACTION: ISSUE A REVISED NPDES GENERAL 

PERMIT 

The proposed CGP requires operators at eligible construction sites to comply with the final ELG 

and NSPS requirements found at 40 CFR Part 450. The proposed CGP includes effluent limits that 

fall into four basic categories: erosion and sediment control; stabilization requirements; pollution 

prevention requirements; and water quality-based effluent limits. The following is a summarization 

of these effluent limitations. 

2.2.3.1 Non-numeric Effluent Limitations in the Proposed CGP 

The non-numeric effluent limitation requirements are technology-based and apply to all discharges 

from construction activities eligible for coverage under this permit. They are organized in three 

major sections: 

• Erosion and Sediment Control; 

• Site Stabilization; and 

• Pollution Prevention. 

The proposed non-numeric effluent limits require operators to “first prevent the discharges of 

sediment and other pollutants through the use of effective planning and erosion control measures; 

and second, to control discharges that do occur through the use of effective sediment control 

measures.” See C&D rule at 74 Fed. Reg. 63016 (December 1, 2009). The effluent limits also 

require the permittee to implement a range of pollution prevention measures to limit or prevent 

discharges of other types of non-sediment discharges. 

2.2.3.1.2 Erosion and Sediment Control Requirements 

The proposed CGP require operators to design, install, and maintain erosion and sediment controls 

that minimize the discharge of pollutants from earth-disturbing activities. In order the accomplish 

this, operators must take into account certain design, installation and maintenance considerations 

when implementing stormwater controls at their site. 

Design considerations include the site’s soil and precipitation characteristics and the nature of the 

stormwater run-off and run-on. The operator is also required to direct non-concentrated or nonchannelized discharges from stormwater controls to vegetated areas of the site, including any 

naturally vegetated buffers established, unless infeasible. Installation of stormwater controls must 

be completed prior to each phase of earth-disturbance, and operators must use good engineering 

practices and follow manufacturer’s specifications. Operators are required to keep stormwater 

controls in effective operating condition; frequent inspections are required including implementing 

and documenting corrective actions immediately if problems occur. 

Examples are summarized in Table 2-2. 
Construction and Development NPDES General Permit Environmental Assessment 

19 

Table 2-2. Proposed CGP Erosion and Sediment Control Requirements 

 Sites with surface waters located on or immediately adjacent to the property must provide 

and maintain a naturally vegetated 50-foot buffer between the area of earth disturbance 

and any surface water or install controls that achieve a sediment load reduction that is 

equivalent to that of a 50-foot buffer. The proposed permit includes a buffer guidance to 

assist operators in complying with this requirement. 

 Sediment controls must be installed around perimeter areas of your site that will receive 

stormwater from earth disturbing activities; sediment must be removed before it has 

accumulated to a height of one-third of perimeter controls. 

 Minimize track-out of sediment from site exit points through use of appropriate 

stabilization techniques. 

 Minimize the disturbance of steep slopes and preserve native topsoil, unless infeasible; if 

infeasible, divert flows around steep slope disturbances and use specialized controls. 

 Controls must address both total volume and peak flow rates; discharges must be directed 

to vegetated areas; and non-stormwater must be directed to sediment control features. 

 Sediment must be managed appropriately as specified (e.g., do not wash sediment into 

stormwater conveyances, storm sewer inlets, or waters of the U.S.; control discharges 

from sediment or soil piles; minimize generating and offsite tracking of dust; minimize 

soil compaction). 

 Conveyance channels must be designed to avoid disturbed areas; concentrated flows must 

be diverted both within and from disturbed soils to prevent further erosion, with special 

attention to reducing velocity. 

 Controls must be established to remove sediment before entering any storm drain inlets on 

the site. 

 Dewatering is only permitted from site accumulations if sediment controls/filters have 

been successfully administered and discharged in compliance with permit requirements 

for water, sediment, and oil and grease or other pollutants.

 Treatment chemicals must be used in conjunction with conventional erosion and sediment 

controls to minimize reliance on its use. Use must comply with dosing specifications as 

well as good engineering and storage practices. Additional, site-specific controls would 

apply to the use of cationic treatment chemicals than to other types of chemicals.5

 

5

 In the proposed permit, EPA contemplates prohibiting the discharge of cationic chemicals, 

establishing maximum dosage rates, and, if the operator intends to use chitosan, residual testing 

requirements. EPA could provide coverage under the CGP for the use of cationic treatment 
Construction and Development NPDES General Permit Environmental Assessment 

20 

2.2.3.1.3 Stabilization Requirements

Stabilization refers to covering ground exposed through the construction process to reduce erosion 

and sedimentation. Stabilization may be temporary or final. Temporary stabilization refers to 

covering exposed soil in areas until final stabilization can be achieved or until the area is disturbed 

again in the future. Final stabilization refers to using practices to provide permanent cover (either 

vegetative or non-vegetative) of exposed portions of the site and qualifies the site for permit 

termination. Temporary and final stabilization can be achieved through the use of vegetative cover 

and non-vegetative cover (e.g., hydromulch, erosion control blankets, riprap) methods. For 

vegetative stabilization, the proposed permit requires the operator to provide uniform vegetation 

that covers 70% or more of the area that was covered by native vegetation prior to the commencing 

of construction activities. Non-vegetative cover for temporary and final stabilization must provide 

effective stabilization of exposed portions of the site. 

The following are the proposed deadlines for initiating and completing stabilization: 

 Immediately initiate stabilization if construction activities in areas of the site have 

permanently or temporarily ceased for 14 or more days, and complete within 14 days 

after the temporary or permanent cessation of earth-disturbing activities. 

 Operators discharging to sensitive waters (i.e., impaired for sediment or nutrients, or 

designated as Tier 2, 2.5, or 3 for antidegradation purposes) are required to complete 

certain stabilization activities in half the time of sites not discharging to such waters. 

 Sites in arid and semi-arid areas are provided with greater flexibility in consideration 

of the unique climatic and soil conditions that are prevalent in these areas. 

2.2.3.1.4 Pollution Prevention Requirements

The proposed CGP contains pollution prevention standards that prohibit certain pollutants from 

being discharged from construction sites including wastewater from concrete washout, fuels and 

oils, soaps/solvents used in vehicle washing, and toxic or hazardous substances from a spill. The 

proposed CGP restricts five types of pollutant-generating activities: 

 Fueling and maintenance of equipment and vehicle; 

 Washing of equipment and vehicles; 

 Staging and storage areas for building materials, equipment, and vehicles; 

 Washing of containers used for paint, concrete, and other materials; and 

 Storage, handling, and disposal of construction waste. 

 

chemicals, or, if it was determined that site-specific considerations and the toxicity concerns 

associated with some polymers warrant, the Agency could require coverage under an individual 

NPDES permit. Under either the CGP or an individual permit, EPA anticipates that the 

requirements affecting the use and storage of cationic treatment chemicals would be the same. 
Construction and Development NPDES General Permit Environmental Assessment 

21 

If an operator will conduct fueling and/or maintenance of equipment or vehicles at the site, an 

effective means must be provided to eliminate the discharge of spilled or leaked chemicals from the 

area designated for this activity. This includes immediate cleanup of contaminated surfaces and 

elimination of the source of the spill using adequate supplies to handle spills, leaks, and disposal of 

liquids. Requirements also include using dry clean up measures where possible and not cleaning 

surfaces by hosing the area down. Additionally, operators must provide an effective means of 

minimizing the discharge of pollutants from equipment and vehicle washing and eliminate the 

discharge of soaps, detergents, or solvents used in vehicle and equipment washing. 

Exposure of products, materials, or wastes stored at the site to stormwater, except for those that are 

either not a source of contamination to stormwater or are designed to be exposed to stormwater, 

must be minimized. Operators must provide cover or similarly effective means to prevent 

discharges. Additional requirements are implemented for storage of particular products, materials 

or wastes such as pesticides, fuel, oil, hydraulic fluids, hazardous waste and domestic waste. These 

products must be stored in sealed, water-tight containers away from exposure to stormwater and 

operators must use dry methods of cleanup where possible in conjunction with proper disposal. 

Where operators will use paint or concrete or conduct other washout activities on site, they must 

provide an effective means of eliminating the discharge of water from these activities. To comply 

with this requirement, washout or cleanout activities must be located as far away as possible from 

surface waters and stormwater inlets or conveyance and all washwater must be directed into a leakproof container or leak-proof pit. The container or pit must be designed so that no overflows can 

occur due to inadequate sizing or precipitation. Additionally, all washout or cleanout wastes must 

not be dumped in storm sewers and hardened concrete wastes must be removed and disposed of 

consistent with construction waste provisions. The proposed CGP also requires immediate 

cleanups of spills, emergency spill notification and reporting requirements for toxic or hazardous 

substance spills, and restrictions on fertilizers containing nitrogen or phosphorus except for 

compost, manure, or other natural fertilizers.

2.2.3.1.5 Best Management Practices (BMPs) to Achieve Non-Numeric Effluent 

Limitations 

Construction site operators comply with the proposed CGP through the implementation of a variety 

of BMPs, which minimize the discharge of pollutants from construction site stormwater discharges 

when selected, implemented, and managed as required. The proposed permit does not dictate that 

any specific BMP be installed on a site; construction site operators have the discretion of choosing 

the BMPs that meet the requirements of the permit and of their project. A more detailed discussion 

of the common BMPs used on construction sites and effectiveness data is included in Section 4.3. 

BMPs selected by construction operators to comply with the proposed permit fall into five general 

categories: 

 Construction Site Planning and Management 

 Erosion Control 

 Runoff Control 

 Sediment Control 
Construction and Development NPDES General Permit Environmental Assessment 

22 

 Good Housekeeping/Materials Management 

Construction Site Planning and Management BMPs emphasize the importance of construction 

sequencing in the specified work schedule to coordinate the timing of land-disturbance and the 

installation of erosion and sediment control measures. The reduction of on-site erosion and off-site 

sedimentation by performing land-disturbing activities and installing erosion and sediment control 

practices in accordance with a planned schedule is the goal of the BMP (Smolen et al., 1988). The 

BMP includes self-inspection and maintenance programs to ensure that the BMP is functioning 

properly to prevent pollution discharges. Awareness and education of general soil and sediment 

controls through this BMP expedites the repair and maintenance efforts by raising issues early. The 

BMP promotes the preservation of natural vegetation (existing trees, vines, brushes, and grasses) 

when possible to provide water quality benefits by intercepting rainfall, filtering stormwater runoff, 

and preventing sediments and other pollutants from leaving the site (USEPA 2011a). 

Construction Site Planning and Management BMPs also emphasize the minimization of clearing 

and grading activities. The intent of this BMP is to manage the terrestrial activities to ensure the 

protection of waterways through a phased construction approach that limits soil exposure. Soils 

that are exposed are intended to be immediately stabilized. The protection of steep slopes and cuts; 

the installation of perimeter controls to filter sediments; and the use of advanced sediment settling 

controls are physical measures described in this BMP category to minimize terrestrial impacts. The 

control of waste at the construction site along with site inspections and maintenance of the BMP 

minimizes terrestrial impacts (USEPA 2011). 

Erosion Control Measure BMPs identify the physical and chemical measures that can be 

implemented on a site to control erosion. Fourteen specific control measures are identified in this 

BMP category: 

 Compost Blankets  Sodding 

 Dust Control  Soil Retention 

 Geotextiles  Soil Roughening 

 Gradient Terraces  Temporary Slope Drain 

 Mulching  Temporary Stream Crossings 

 Riprap  Wind and Sand Fences 

 Seeding  Chemical Stabilization 

When selected and implemented as designed, these control measures minimize the discharge of 

sediment by controlling erosion on sites. 

Runoff Control BMPs emphasize the implementation of rock check dams, grass-lined channels, 

slope diversion channels, and temporary diversion dikes to control runoff. Rock check dams are 

recommended for long channels. Check dams are most effective when used in a series, creating 

multiple barriers to sediment-laden runoff. Rock check dams are more effective than silt fences or 

straw bales to stabilize wet-weather ditches. Grass-lined channels can effectively transport 

stormwater from construction areas if they are designed for expected flow rates and velocities and if 

they do not receive sediment directly from disturbed areas. Permanent slope diversions are 

designed to transport runoff down a slope in a manner that minimizes the potential for erosion. 
Construction and Development NPDES General Permit Environmental Assessment 

23 

Diversions can be constructed by creating channels laterally across slopes to intercept the downslope flow of runoff. The channels have a supporting earthen ridge on the bottom sides to reduce 

slope length, collect stormwater runoff, and deflect the runoff to outlets that convey it without 

causing erosion. When properly placed and maintained, earth dikes used as temporary diversions 

can control the velocity and direction of stormwater runoff. Used by themselves, they do not have 

any pollutant removal capability. They must be used with an appropriate sediment-trapping device 

at the outfall of the diversion channel. These runoff control BMPS are designed to minimize 

impacts by controlling runoff (USEPA 2011). 

Sediment Control BMPs identify the physical measures and devices that can be implemented on a 

site to control sediment. Thirteen specific control measures are identified in this BMP category: 

 Brush barrier  Sediment filters and sediment chambers 

 Compost filter berms  Sediment traps 

 Compost filter socks  Silt fences 

 Construction entrances  Storm drain inlet protection 

 Fiber rolls  Straw or hay bales 

 Filter berms  Vegetated buffers 

 Sediment basins and rock dams 

When selected and implemented as designed, these control measures minimize the impacts to the 

quality of the discharge by controlling sediment on sites. 

Good Housekeeping/ Materials Management BMPs address concrete washout, building 

materials/site waste, spill prevention/control plans, and vehicle maintenance/washing activities. 

Concrete washout BMPs are used to contain concrete and liquids when the chutes of concrete 

mixers and hoppers of concrete pumps are rinsed out after delivery. The washout facilities 

consolidate solids for easier disposal and prevent runoff of liquids. The wash water is alkaline and 

contains high levels of chromium, which can leach into the ground and contaminate groundwater. 

It can also migrate to a storm drain, which can increase the pH of area waters and harm aquatic life. 

Solids that are improperly disposed of can clog storm drain pipes and cause flooding. Installing 

concrete washout facilities not only prevents pollution but also is a matter of good housekeeping at 

the construction site (USEPA 2011). 

Building materials and other construction site wastes must be properly managed and disposed of to 

reduce the risk of pollution from materials such as surplus or refuse building materials or hazardous 

wastes. Practices such as trash disposal, recycling, proper material handling, and spill prevention 

and cleanup measures can reduce the potential for stormwater runoff to mobilize construction site 

wastes and contaminate surface or ground water. Waste management practices are effective only 

when they are regularly practiced at a construction site. In storage and use areas, it is recommended 

to post the guidelines for proper handling, storage, and disposal of construction site wastes; the 

training of workers is recommended in these practices to ensure that everyone is knowledgeable 

enough to participate (USEPA 2011). 

Spill Prevention and Control Plans (SPCP) clearly state measures to stop the source of a spill, 

contain the spill, clean up the spill, dispose of contaminated materials, and train personnel to 
Construction and Development NPDES General Permit Environmental Assessment 

24 

prevent and control future spills. An SPCP can be highly effective at reducing the risk of surface 

and ground water contamination; however, to ensure that procedures are followed, a construction 

site operator should provide worker training, appropriate materials and equipment for cleanup, and 

adequate staff time (USEPA 2011). 

Vehicle maintenance and washing occurs in garages and wash facilities, not on active construction 

sites. However, if these activities must occur onsite, operators should follow appropriate BMPs to 

prevent untreated nutrient-enriched wastewater or hazardous wastes from being discharged to 

surface or ground waters. These techniques effectively reduce discharges of untreated automotive 

wastes and wash water to receiving waters. Their effectiveness highly depends on personnel's 

training and level of commitment to follow procedures (USEPA 2011). 

BMPs, when selected and implemented as designed, offer an effective approach in minimizing 

discharges of pollutants from construction site stormwater discharges. 

2.2.3.2Water Quality­Based Effluent Limitations

The 2012 CGP includes provisions for meeting water quality standards in three categories. One 

category includes the general effluent limitation to meet applicable water quality standards. The 

second category includes discharge limitations for impaired waters, defined as those identified on 

the CWA Section 303(d) list or waters with an EPA-approved or established TMDL. The third 

category includes the discharge requirements for waters identified by a state, tribe, or EPA as Tier 3 

(outstanding national resource waters) or Tier 2/2.5 waters (high quality waters) for the purpose of 

non-degradation determinations. The proposed permit requires more stringent requirements for 

sites discharging to impaired or to high-quality waters, including more stringent stabilization 

deadlines and more frequent site inspections to supplement the permits non-numeric technology 

based effluent limits discussed above. 

2.2.3.2.2 General Water Quality-based Effluent Limitations 

Discharges must be controlled to meet applicable water quality standards, as well as any further 

state or tribal requirements that are included in the proposed CGP as part of the state or tribe’s 

CWA Section 401 certification. EPA has made an affirmative determination that, absent any 

information demonstrating otherwise, compliance with the terms and conditions of the proposed 

permit is sufficient to control stormwater discharges to comply with water quality standards. If the 

operator or EPA become aware that stormwater discharges are not meeting applicable standards, 

corrective action will be required. EPA may also impose additional water quality-based site-specific 

requirements or require coverage under an individual permit if information is provided that 

indicates water quality standards are not met due to insufficiently controlled stormwater discharges 

from a C&D site covered under the CGP. 

2.2.3.2.3 Water Quality-based Discharge Limitations for Impaired Waters 

A construction site will be considered to discharge to an impaired water if the first water of the U.S. 

to which it discharges is identified by a state, tribe, or EPA pursuant to Section 303(d) of the CWA 

as not meeting an applicable water quality standard, or is included in an EPA-approved or 

established total maximum daily load (TMDL). For discharges that enter a storm sewer system 

prior to discharge, the first water of the U.S. to which the site discharges is the waterbody that 
Construction and Development NPDES General Permit Environmental Assessment 

25 

receives the stormwater discharge from the storm sewer system. If the site discharges to an 

impaired waterbody, the construction site operator must provide: a list of all impaired waters, the 

pollutants causing impairment, and a reference to any approved or established TMDL. 

If the site discharges to a surface water that is impaired for sediment or a sediment-related 

parameter such as total suspended solids (TSS) or turbidity, and/or nutrients, including impairments 

for nitrogen and/or phosphorus, the proposed permit requires the site operator to meet the following 

additional requirements: 

 Comply with any additional state or tribal impairment-related requirements included in the 

permit. 

 Meet deadlines for stabilization that are shorter than for other sites not discharging to such 

waters. 

 Conduct more frequent site inspections. 

The stabilization requirements described above (Section 2.2.3.1.3) are superseded by the following 

requirement for sites discharging to waters impaired for sediment, sediment-related, or nutrients: 

 Immediately begin stabilization when earth-disturbing activities permanently or temporarily 

cease for at least 7 calendar days 

Construction site operators must comply with the following site inspection requirement for sites 

discharging to waters impaired for sediment, sediment-related, or nutrients: 

 Inspect the site at a minimum of once every 7 calendar days and within 24 hours of 0.25 

inch or greater storm event. 

2.2.3.2.4 Water Quality-based Discharge Limitations for Tier 2, 2.5, or 3 

Waters 

A construction site will be considered to discharge to a Tier 3, Tier 2, Tier 2.5, or 3 water if the first 

water-body to which it discharges is designated as a Tier 3, 2, or 2.5 water. For sites that discharge 

to a storm sewer system, they would be considered to discharge to a Tier 3, 2, or 2.5 water if the 

first surface water receiving the discharge from the sewer system is designated as a Tier 3, 2, or 2.5 

water. The proposed permit requires construction sites discharging to these waters to comply with 

the same requirements as those required of discharges to sediment or nutrient-impaired waters. 

2.2.3.3 Site Inspections and Corrective Actions 

Inspections must be conducted by a “qualified person”, who is knowledgeable in the principles and 

practice of erosion and sediment controls, and pollution prevention, who possesses the skills to 

assess conditions at the construction site that could impact stormwater quality, and the skills to 

assess the effectiveness of any stormwater control measures selected to control the quality of 

stormwater discharges from the construction activity. This may be conducted by an authorized 

representative of the EPA, or another federal, state, local or tribal agency. While the proposed 

permit establishes the required minimum inspection frequency of once every 7 calendar days or 

once every 14 days and within 24 hours of the occurrence of a storm event of 0.25 inches or greater, 

increases and decreases in inspections can occur and are outlined in the permit depending on site 
Construction and Development NPDES General Permit Environmental Assessment 

26 

conditions. Inspection frequency increases for sites that discharges to a sediment or nutrientimpaired water or to a water that is identified by your state, tribe, or EPA as Tier 2, Tier 2.5, or 

Tier 3 for antidegradation purposes and decreases for certain arid and semi-arid areas and frozen 

conditions. Additionally, the proposed permit lays out the required areas and activities to be 

inspected; including requirements for an inspection report to be completed within 24 hours of any 

site inspection. 

Operators must immediately take all reasonable steps to minimize or prevent the discharge of 

pollutants until a permanent solution and corrective action is installed and made operational, or if 

applicable, clean up any contaminated surfaces so that the material will not discharge in subsequent 

storm events. Within 7 days of discovery, operators must institute corrective actions followed by a 

corrective action report and progress update within one week of implementing the corrective action. 

Any corrective actions required by EPA as a result of a permit violation during inspection must be 

complied with. 

2.2.3.4 Stormwater Pollution Prevention Plan (SWPP) Requirements 

In order to gain coverage under the proposed CGP, operators must develop a stormwater pollution 

prevention plan (SWPPP) prior to submitting their NOI that describes the nature and location of the 

construction activities, including the physical attributes of the site, a list of pollutants and pollutantgenerating activities occurring on the site, certain characteristics of the stormwater discharge, and 

the people responsible for implementation activities under this permit. Additional information must 

be included in the SWPPP on the selection, design, installation, and maintenance of stormwater 

control measures used to control pollutants in discharges from the site in order to satisfy the effluent 

limitations in the permit. The SWPPP must include documentation of compliance with other 

federal requirements such as the Endangered Species Act (ESA). SWPPP’s must be available on 

site or at an easily accessible location so that is can be made available during site inspections and 

upon request. 

 
Construction and Development NPDES General Permit Environmental Assessment 

27 

3. AFFECTED ENVIRONMENT

3.1 INTRODUCTION 

This chapter describes the physical, biological, and socioeconomic resources that may be affected 

by stormwater discharges from large and small construction activities covered under the proposed 

2012 CGP. To satisfy the requirements of 1502.2(b) of CEQ’s NEPA implementing regulations, 

this EA focuses on resource values potentially subject to impact and critical elements of the human 

environment unless they are either not present in the affected environment, or present but not 

affected. 

When considering the affected environment, it is necessary to define the geographic scope of the 

proposed action. Since the proposed action of issuing a revised Construction General Permit is only 

applicable where EPA is the permitting authority, the geographic scope includes four states (Idaho, 

Massachusetts, New Hampshire, and New Mexico), the District of Columbia, Puerto Rico, all other 

U.S. territories with the exception of the Virgin Islands, federal facilities in four states (Colorado, 

Delaware, Vermont, and Washington), most Indian lands and other specifically designated activities 

in specific states (e.g., oil and gas activities in Texas and Oklahoma). 

3.2 PHYSICAL RESOURCES 

EPA estimates that construction takes place on 853,000 acres annually in the continental US and 

that stormwater discharges from these sites release more than 5 billion pounds of sediment into 

surface waters (USEPA 2009a). All major surface water types receive construction discharges, 

including streams, rivers, wetlands, lakes, estuaries, and coastal waters. In any given year, some 

level of construction activity occurs in the majority of U.S. watersheds. However, EPA’s review 

found most construction acreage is concentrated in a relatively limited number of watersheds in any 

given year. Based on analysis of the watersheds associated with more than 62,000 surface water 

reaches in the conterminous United States, between 1992 and 2001 more than 50% of all C&D 

activity occurred in less than 5% of U.S. watersheds (USEPA 2007). A common development 

pattern from this analysis of where C&D activity occurred was that new construction concentrated 

in rural and suburban watersheds adjacent to more densely developed urban areas. However, 

because C&D activity is of a temporary nature, the locations of the most highly impacted 

watersheds in the US shift over time. 

Typical construction activities include clearing vegetation; excavating, moving, and compacting 

earth and rock. Since, soil and sediment are composed of organic matter, nutrients such as 

phosphorus and nitrogen, metals, and other natural and synthetic compounds. Many of these 

components travel with soil particles that have eroded and are discharged to surface waters. 

3.2.2 WATER RESOURCES

EPA used the National Land Cover Dataset (NLCD) to estimate the amount of newly developed 

land occurring annually in the continental United States (CONUS) between 1992 and 2001 

(USEPA 2009a). By overlaying geographic information system (GIS) layers of states and 

watersheds with the NLCD data, EPA was able to estimate the annual number of acres of new 

development at both the state and watershed level between 1992 and 2001. EPA estimated annual 

development rates between 1992 and 2001 for approximately 44,000 watersheds where a net 

increase in urban land cover was identified. Approximately 7,800 additional watersheds showed 
Construction and Development NPDES General Permit Environmental Assessment 

28 

either no change or a minor decrease in urban land uses between 1992 and 2001 (USEPA 2009a). 

While stormwater discharges from construction activity are generally related to effects on 

freshwater watersheds, both freshwater and marine ecosystems are affected. 

3.2.2.1Freshwater Ecosystems

EPA defines a freshwater ecosystem as an aquatic system which contains drinkable water or water 

of almost no salt content (http://www.epa.gov/bioiweb1/aquatic/freshwater.html). Freshwater 

resources include streams, rivers, ponds, lakes, reservoirs, wetlands, and groundwater. These 

freshwater resources provide source water for drinking, agriculture, industry, and sanitation; 

support recreation, e.g., swimming, fishing, and boating; and are a source of food, e.g., fish, 

crustaceans, and shellfish. Lakes, ponds, and reservoirs act as deposition zones (ecological sinks) 

for sediments. Longer flow residence times also mean that an influx of turbid water can persist for 

longer periods of time than would occur in streams or rivers. Residence times vary widely among 

lakes, ponds, and reservoirs (USEPA 2009b). Table 3-1 indicates general characteristic differences 

between lakes, ponds and reservoirs. 

Table 3-1. Some Characteristic Differences between Lakes, Ponds, and Reservoirs 

Lakes Ponds Reservoirs 

Larger Smaller Varying sizes but usually larger 

May have dramatically different 

temperatures from surface to bottom 

waters 

Top to bottom waters generally 

have the same temperature 

Similar to lakes may have 

dramatically different temperatures 

from surface to bottom waters 

Light generally does not reach bottom at 

deeper points 

Light generally will reach the 

bottom in all areas of the pond 

Light generally does not reach 

bottom at deeper points 

Generally can only support rooted plants 

at shoreline 

Can support rooted plants across 

the entire pond 

Generally can only support rooted 

plants at shoreline 

Lakes are natural Ponds are usually man-made Man-made 

Can affect local climate if large enough Tend to be greatly affected by local 

climate 

Can affect local climate if large 

enough 

Source: EPA 2009b

Lakes are inland bodies of fresh water and can range in size from less than one acre to several 

thousands of acres. Reservoirs are lakes, often man-made, that control water flow for hydroelectric 

power generation, flood control, and/or municipal water supplies. 

Lakes vary physically in terms of light levels, temperature, and water currents; chemically, in terms 

of nutrients, major ions, and contaminants; biologically, in terms of community structure and 

function; and dynamically, in terms of biomass, population numbers, and growth rates. 

A fundamental set of properties of lakes is the interaction among light, temperature and wind 

mixing. The absorption and attenuation of light by the water column control temperature and 

photosynthesis, which provides food and much of the dissolved oxygen in the water. Solar radiation 

is nearly always the major source of heat and is a major factor in the wind patterns of the lake basin 

and lake water movements. 

Rivers and streams are general terms used to describe bodies of moving water. Rivers are larger 

than streams and empty into larger waterbodies such as oceans and lakes. River and stream systems 
Construction and Development NPDES General Permit Environmental Assessment 

29 

consist of numerous tributaries. Streams are typically identified by their stream order, categorized 

in three main types: 

 Ephemeral streams regularly exist for short periods of time, usually during a rainy period, 

and may have defined channels even when they are dry 

 Intermittent streams flow at different times of the year, or seasonally, when there is enough 

water from rainfall, springs, or other surface sources such as melting snow or even discharge 

from a wastewater treatment facility 

 Perennial streams are those that flow year-round. 

Silt and organic materials settle and accumulate in the streambed of slowly flowing rivers and 

streams. These materials decay and become the primary food resource for the invertebrates 

inhabiting the streambed. Nutrient levels and sediment loads often vary throughout the different 

locations along the course of a mature river/stream and, therefore, affect velocity and current. 

Wetlands are natural sediment deposition zones. Water flow volumes and velocities are smaller 

than in most other surface water types, allowing time for settling of sediment from the water 

column. However, because of lower flow volumes and speeds, influxes of turbid and sedimentladen water also typically remain for a longer period of time in a wetland than they do in a stream 

or river channel. Wetland ecosystem structure is heavily influenced by the type of vegetation the 

wetland supports, which is influenced by water and sediment distribution in the wetland. 

Sedimentation levels can change the types of vegetation in the wetland, with consequences for the 

organisms the wetland supports. 

3.2.2.2  Marine Ecosystems

Marine ecosystems are a part of the largest aquatic system on the planet, covering over 70% of the 

Earth's surface. The habitats that make up this system range from highly productive nearshore 

coastal regions to the relatively barren ocean floor. Some examples of important marine ecosystems 

are: 

 Oceans 

 Estuaries and salt marshes 

 Coral reefs and other tropical communities (e.g., mangrove forests) 

 Coastal areas like lagoons, kelp and seagrass beds, and intertidal systems (rocky, sandy, and 

muddy shores). 

Marine ecosystems are highly diverse, with species ranging from tiny planktonic organisms that 

form the base of the marine food web (i.e., phytoplankton and zooplankton) to large marine 

mammals such as whales, manatees, and seals. Numerous fish species reside in marine ecosystems, 

and birds, including shorebirds, gulls, wading birds, and terns, are equally plentiful. 

Like other aquatic ecosystems, marine ecosystems require nutrients and light to produce food and 

energy and are limiting factors in marine ecosystem productivity. Like many other aquatic plants, 

photosynthetic marine organisms rely on sunlight and chlorophyll to produce food and energy. 

However, light penetration decreases with increasing water depth similar to freshwater systems, but 

given the much greater depths of the oceans, photosynthesis can only take place in a very small 

fraction of ocean waters near the surface, called the photic zone. 

Nutrient availability also varies very widely spatially. Nearshore waters, such as estuaries and 

marshes, are often rich in nutrients, allowing primary production to be very high and to support 
Construction and Development NPDES General Permit Environmental Assessment 

30 

diverse and abundant ecological communities. However, excess nutrient loads can cause an overstimulation of primary production whose decomposition results in depleted oxygen levels causing 

eutrophic conditions, or “dead zones, in coastal and nearshore habitats. 

Estuaries vary widely in benthic geometries, residence times, flushing rates, vertical mixing, 

stratification, wave exposure, and other factors that govern sediment transport and deposition. 

When turbid, sediment-laden freshwater decelerates and encounters tidal cycles in the estuary, a 

zone forms where the channel discharge and tidal action largely cancel each other out, resulting in 

deposition of suspended sediment (Chapra 1997). Additionally, increasing salinity favors 

flocculation of fine sediments. As a result, large deltas often form where rivers deposit sediments in 

coastal waters. 

Marine ecosystems are very important to the health of both marine and terrestrial environments. 

Mangroves, reefs, and seagrass beds provide physical protection to coastlines; salt marshes and 

estuaries act as sediment sinks and filter terrestrial runoff; coastal habitats alone account for 

approximately one-third of all marine biological productivity. Estuarine ecosystems (i.e., salt 

marshes, seagrasses, mangrove forests, etc) are among the most biologically productive regions on 

the planet. 

3.2.2.3  Human Use

There are many human uses of surface waters such as transportation, reservoirs, drinking water and 

recreation which should be considered. Navigable waterways, including rivers, lakes, bays, harbors, 

and shipping channels and canals are an integral part of the Nation’s transportation and commerce 

infrastructure. The US Army Corps of Engineers (USACE) operates and maintains 12,000 miles of 

navigable channels in the US’s inland and intracoastal waterways; operates 192 commercial lock 

and dam sites; and is responsible for ports and waterways in 41 states (USACE 2009). 

Reservoirs are water impoundments that provide drinking water, flood control, hydropower supply 

and recreational opportunities. The National Inventory of Dams includes more than 75,000 dams 

and an estimated 375,000–750,000 additional man-made impoundments in the United States 

(Renwick et al. 2005). Smaller impoundments are used for recreation, livestock water supply, 

sediment trapping and erosion control, and other purposes. 

There are approximately 155,000 public water systems in the United States. EPA classifies these 

water systems according to the number of people they serve, the source of their water, and whether 

they serve the same customers year-round or on an occasional basis (USEPA 2011b). 

Lastly, a variety of recreational activities take place in or near surface waters including boating; 

swimming; hunting; and outings to hike, jog, picnic, camp, and view wildlife. 

3.3 BIOLOGICAL RESOURCES 

The overwhelming majority of direct and indirect environmental impacts resulting from stormwater 

discharges are felt in the aquatic environment. Therefore, EPA’s discussion is primarily focused on 

aquatic ecosystems. 

3.3.1 AQUATIC VEGETATION AND WILDLIFE RESOURCES

Freshwater (including both fresh water and estuarine species) and saltwater aquatic organisms share 

more than the common bond of living in water media. Freshwater and marine ecosystems are 

similar in most aspects, with the most obvious difference in the salinity of the aquatic media they 

inhabit. From primary producers like algae and seagrasses, to macro-invertebrates, to the top 
Construction and Development NPDES General Permit Environmental Assessment 

31 

carnivores, freshwater and marine organisms share the same ancestry and ecological functions. The 

marine ecosystem is more biologically diverse, but the species that dominate in shallow coastal 

waters, estuaries, lakes, and rivers tend to be from the same phylum. Estuarine and marine species 

that C&D industry-related stormwater could impact occupy similar niches and generally perform 

the same community functions as those found in freshwater ecosystems. Organisms within coastal 

and estuarine ecosystems that are biologically similar to their freshwater counterparts include 

vertebrates (e.g., fish, amphibians, reptiles, birds, and mammals), invertebrates (e.g., zooplankton, 

crustaceans, worms, mollusks), and algae and occupy similar niches in the marine ecosystems as 

they do in the freshwater environment. 

Some major groups of organisms known to inhabit aquatic ecosystems include algae, fungi, 

bacteria, plants, invertebrates (e.g., protozoan, rotifers, worms, mollusks), and vertebrates (e.g., 

fish, amphibians, reptiles, birds, and mammals). Infectious agents such as viruses are also present. 

Phytoplankton and zooplankton form the base of the food chain in aquatic environments. 

Periphyton, macrophytes (aquatic plants), insects (although only found in freshwater and estuarine 

ecosystems), fish, and amphibians are found in both freshwater and marine environments. Various 

bird species such as ducks, gulls, pelicans, eagles and ospreys also are supported by freshwater and 

marine systems. 

Primary producers, including algae, phytoplankton, submerged aquatic vegetation, and other 

macrophytes, are found in most aquatic ecosystems. Aquatic ecosystems vary in the degree to 

which they derive energy and resources from primary producers. Some systems (e.g., small streams 

in forested watersheds) derive a large proportion of their energy from external sources (e.g., leaf 

debris) (Bilotta and Brazier 2008). Other systems are heavily dependent on the productivity of 

primary producers (e.g., seagrass beds). 

Aquatic invertebrates, including zooplankton, insects, crustaceans, annelids, are widely distributed 

among aquatic ecosystems and can be found in even the smallest surface waters. They are filter 

feeders, suspension feeders, predators and scavengers. These organisms inhabit the bottom 

substrates of ponds, lakes, rivers, streams, estuaries, and nearshore coastal waters. They also play a 

vital role in maintaining sediment and water quality. They provide an important link in the aquatic 

food chain between primary producers and larger organisms such as amphibians, reptiles, fish, 

birds, and mammals (Waters 1995). Table 3-2 lists the major classification of aquatic organisms, 

and common names for species within each classification. 

The freshwaters of North America are populated by a rich array of native fishes. While names such 

as trout and bass are well-embedded into the American vernacular, less familiar groups such as 

darter, madtom, and dace remain relatively unknown. Freshwater fishes comprise eight Orders in 

the taxonomic classification with over 1,000 species. 

The freshwater fishes of North America occupy a variety of habitats, ranging from narrow roadside 

ditches to large rivers and lakes. The factors that dictate the distribution of a particular species 

include climate, physiography, hydrology, stream size, biogeography, geochemistry, and human 

disturbance. The last factor has become increasingly important as a growing human population 

increases its demands on the natural environment (USEPA 2008). 

Table 3-2. Common Names of Prevalent Freshwater, Estuarine, and Saltwater 

Organisms 
Construction and Development NPDES General Permit Environmental Assessment 

32 

Classification Freshwater Estuarine/Marine 

Algae Diatoms, Stonewarts, Green Algae, 

Dinoflagettes, Euglenoids Green algae, Blue-green algae, Kelp 

Macrophytes Water lily, Pondweed, Wild celery, 

Water hyacinth, Water lettuce 

Turtle grass, Eel grass, Widgeon 

grass 

Invertebrates Mayfly, Stonefly, crawfish, Isopods, 

Snails, Clams Shrimp, Blue crab, Oysters, Clams 

Vertebrates Frogs, Newts, Salamanders, Osprey, 

Bald eagles, Fishes1 

Green sea Turtles, leatherback 

turtles, Manatees, Least terns, 

Pelicans, Fishes

Like freshwater fishes of North America, coastal/estuarine fishes occupy a variety of habitats, 

ranging from small tidal creeks to open ocean. The size of coastal/estuarine fishes ranges from a 

few millimeters to over three meters. Most are free swimming, live in close relationship with the 

bottom or burrow into the bottom. They may be herbivores, carnivores, and/or scavengers. Coastal 

and estuarine fishes encompass more than 16 Orders in the taxonomic classification, and like 

freshwater fishes, range from herbivores to piscivores in trophic classification. 

Nearshore coastal ecosystems are influenced by terrestrial activities, such as C&D, through river 

drainage to rivers, estuaries and bays. Near coastal ecosystems provide recreational and commercial 

catch far out of proportion to the marine ecosystem as a whole. The National Marine Fisheries 

Service (NMFS) reported that 39% of the commercial fisheries harvest (3.3 billion pounds) was 

taken within 3 miles of shore. Inland catch (e.g., fishing in sounds, rivers and/or bays) represented 

45% of total marine recreational catch, while 29% of total recreational catch was from shore. 

NMFS also notes that the top five species either harvested or released were species commonly 

found within the 0-3 mile zone (NMFS 2009). 

3.3.2 TERRESTRIAL VEGETATION AND WILDLIFE RESOURCES

Terrestrial ecosystems differ from aquatic ecosystem by the lower availability and consequent 

importance of water as a limiting factor. Organisms in a terrestrial ecosystem are adapted to obtain 

and retain water. 

Plants of the terrestrial ecosystem include mosses, liverworts, non-vascular and vascular plants, 

with the vascular plants providing the majority of primary productivity. They range from deep 

forest to grasslands to desert ecosystems. Terrestrial plants provide nutrient transport and ground 

cover. They are a valuable food source for wildlife and humans, as well as a source of beauty to our 

landscape. 

Invertebrates live in most terrestrial ecosystem and are primarily from two Classes, Insecta and 

Arachnida, within the Phylum Arthropoda. Invertebrate adults and larvae are an important food 

source for much of both aquatic and terrestrial wildlife. They also can be as much of a nuisance — 

consuming crops and food stored for human consumption, as well as serving as vectors for many 

human pathogens — as they are ecologically beneficial. 

Vertebrates include birds, mammals, reptiles, and amphibians and are the top consumers of the 

terrestrial ecosystem. These organisms use both terrestrial and aquatic systems for shelter, 
Construction and Development NPDES General Permit Environmental Assessment 

33 

reproduction and food. Some vertebrates, such as mammals and birds, are mobile, while others, 

such as reptiles and amphibians, are tied directly and closely to aquatic systems. 

3.3.3 THREATENED & ENDANGERED SPECIES

The current U.S. Fish and Wildlife Service (USFWS) list of threatened and endangered (T&E) 

species includes 580 animal species and 795 plant species in the U.S. and 1,976 plant and animal 

species both foreign and domestic (USFWS 2011a). The National Marine Fisheries Service 

(NMFS) is responsible for the stewardship of the nation's living marine resources, anadromous fish, 

and their habitat. NMFS has jurisdiction over 74 listed species (NMFS 2011a). NMFS is 

responsible for the management, conservation and protection of living marine resources within the 

United States' Exclusive Economic Zone (water three to 200 miles offshore). 

A species is federally listed as “endangered” when it is likely to become extinct within the 

foreseeable future throughout all or part of its range if no immediate action is taken to protect it. A 

species is listed as “threatened” if it is likely to become endangered within the foreseeable future 

throughout all or most of its range if no action is taken to protect it. The 1973 ESA outlines detailed 

procedures used by the Services to list a species, including listing criteria, public comment periods, 

hearings, notifications, time limits for final action, and other related issues. 

A species is considered to be federally threatened or endangered if one or more of the following 

listing criteria apply: 

 The species’ habitat or range is currently undergoing or is jeopardized by destruction, 

modification, or curtailment. 

 The species is overused for commercial, recreational, scientific, or educational purposes. 

 The species’ existence is vulnerable because of predation or disease. 

 Current regulatory mechanisms do not provide adequate protection. 

 The continued existence of a species is affected by other natural or manmade factors. 

Information on federally listed T&E species is available from the USFWS Threatened and 

Endangered Species System (TESS) database (USFWS 2011a), available at: 

http://ecos.fws.gov/tess_public/ and from NMFS at 

http://www.nmfs.noaa.gov/pr/species/esa/ (NMFS 2011a). Additional information on state-listed 

species is available from state T&E species coordinators. 

The ESA also requires the federal government to designate “critical habitat” for any species it lists 

under the ESA. Critical habitat is defined as: 

 Specific areas within the geographical area occupied by the species at the time of listing, if 

they contain physical or biological features essential to conservation, and those features may 

require special management considerations or protection; and 
Construction and Development NPDES General Permit Environmental Assessment 

34 

 Specific areas outside the geographical area occupied by the species if the agency 

determines that the area itself is essential for conservation of a threatened or endangered 

species and that may require special management and protection. Critical habitat may 

include an area that is not currently occupied by the species but that will be needed for its 

recovery. 

Critical habitat designations must be based on the best scientific information available, in an open 

public process, within specific timeframes. The final boundaries of the critical habitat area are also 

published in the Federal Register. 

Under Section 7 of the ESA, all Federal agencies must ensure that any actions they authorize, fund, 

or carry out are not likely to jeopardize the continued existence of a listed species, or destroy or 

adversely modify its designated critical habitat. Critical habitat has been designated for 607 species 

listed as threatened or endangered under USFWS and 24 species listed as threatened or endangered 

under NMFS (NMFS 2011a; USFWS 2011a). 

3.4 SOCIOECONOMIC RESOURCES 

The C&D industry plays an integral role in the nation’s economy, contributing approximately 5% 

of the Gross Domestic Product. Approximately 10% of the nation’s nearly 7 million total business 

establishments are in the C&D industry. The number of paid employees in the C&D industry 

accounts for 6.6% of total US employment (US Census Bureau 2005a). Establishments in this 

industry are involved in a wide variety of activities, including land development and subdivision, 

homebuilding, remodeling, construction of nonresidential buildings and other structures, and heavy 

construction work (including roadways and bridges). Establishments are also involved in myriad 

special trades, such as plumbing, roofing, electrical, excavation, and demolition work. Some of 

these activities result in land disturbance, which can cause erosion and transport of soil and 

sediment in stormwater discharges. In developing the C&D Rule, EPA conducted a comprehensive 

study of the socioeconomic impacts of the Rule. Since the CGP must incorporate the requirements 

of the C&D Rule, some of the analysis of the socioeconomic impacts have been incorporated by 

reference into the EA. (USEPA, 2009b) 

3.4.1 LAND USE

According to the Department of Agriculture’s Economic Research Service, the largest proportion 

(51%) of land use in the US continues to be agriculture; the next largest category of land use, at 

22%, is forests. In 2002, urban land comprised only 3% of total US land use. However, urban area 

increased by 13% between 1990 and 2002. In addition, the estimated acreage of rural land used for 

residential purposes increased by 30% (17 million acres) from 1980 to 1997 and by 29% (21 

million acres) from 1997 to 2002 (USDA, 2006)

For the C&D Rule economic impact analysis, EPA considered two categories of land use affects: 

(1) impacts to existing land uses due to changes in water quality from construction activity 

discharges; and (2) direct land disturbing acreage due to development as a measure of C&D 

activity. 
Construction and Development NPDES General Permit Environmental Assessment 

35 

EPA estimates that as C&D activities continue in areas close to or adjoining agricultural land, 

impacts from C&D activities may impact agricultural areas, particularly water sediment levels. 

Agriculture depends on water for irrigation, which may require treatment to lower particulate levels 

to the degree needed to avoid pump and delivery system problems, particularly for drip and fine 

spray systems. 

The C&D industry inherently changes land use by either demolishing existing structures and 

constructing different ones, such as roads and highways, or changing rural or agricultural land into 

developed land. The C&D industry, as defined by EPA for this permit analysis, comprises three 

main industry groups: 

 Building construction, including 

▫ Residential: single-family, multifamily, remodelers, and operative construction 

▫ Non-Residential: industrial and commercial/institutional building construction 

 Heavy and civil engineering construction 

 Specialty trade contractors: wrecking and demolition contractors, and all other heavy 

construction. 

Of these three industry groups, EPA considers only the first two as likely to engage in landdisturbing activities requiring coverage under the proposed CGP. The activities EPA considers to be 

land-disturbing activities include site clearing or preparation activities, such as tree removal, 

excavation, blasting, scraping, grading, etc. These activities can destabilize soils and create 

conditions that allow stormwater to accumulate and flow across the site. This increase in 

stormwater flow can cause erosion and lead to the transport of soil particles (USEPA, 2009c).

Within the building construction category, EPA considers residential remodelers as a category that 

would not be likely to engage in land-disturbing activities. 

EPA’s C&D Rule economic analysis estimated construction activity in terms of acreage developed 

and how that activity was distributed geographically and across C&D industry segments. EPA used 

development rates and types in different areas of the US from previous years to describe past trends 

and future activity. EPA utilized US Census data and economic activity data to determine the 

geographic levels of construction and development activity. 

EPA characterized potentially affected acreage into various future land uses, construction project 

sizes, and project durations as the basis for developing mathematical models to represent broad 

sectors of the C&D industry. Beginning with the 2003 CGP, the C&D industry submitted Notices 

of Intent (NOIs) to cover their stormwater discharges under the NPDES general permit. NOI 

records were characterized on the basis of land use, site construction acreage, and project duration 

information. EPA identified 36 C&D project groupings based on 12 site size categories, three major 

land-use types, and 12 categories of project duration . EPA then developed a distribution of model 

projects in these various categories that represented construction projects developed annually and 

that covered the major C&D industry project types. To develop the baseline profile of acreage 

activity by state and construction activity sector, EPA distributed the approximately 853,000 acres 

affected by C&D activity as projected in the model project matrix in proportion to the total 2008-

trend value of construction estimated to occur in each category. 

3.4.2 POPULATION AND HOUSING

In 2009, EPA used The National Land Cover Database (NLCD) as a national source of data on land 

cover change. NLCD data are publicly available for the years 1992 and 2001(see: 
Construction and Development NPDES General Permit Environmental Assessment 

36 

http://edc2.usgs.gov/pubslists/factsheets/fs10800.pdf for 1992 and http://www.mrlc.gov/ pdf/nlcd_ 

fact_sheet_2001.pdf for 2001). The USGS prepared and released a comparative land use analysis, 

the NLCD 1992/2001 Retrofit Land Cover Change Product (see http://www.epa.gov/mrlc; 

http://www.mrlc.gov/). USGS developed this product to offer more accurate direct change analysis 

between the 2001 and 1992 individual maps. EPA used this product to estimate the amount and 

geographic areas of land converted to urban land uses in the US between 1992 and 2001. Appendix 

A graphically presents the NLCD development change for each of the 10 EPA regions. 

The geographic data from the NLCD overlay maps shows that the most intensive development, 

represented by the greatest percentage urban change, tends to occur in and around existing 

metropolitan areas. However, regional-scale population shifts also have occurred, for example 

greater population growth in the Southeast versus less growth in the Northeast, and such population 

shifts also coincide with increases in housing development. However, the time period of the NLCD 

mapping precedes the real estate downturn of 2008 – 2010 and the significant drop in housing 

development, particularly for California and Florida. 

The trends shown in the NLCD maps were also corroborated by summary 2010 Census Data. 

According to the Census data, regional population growth trends seem to continue with the largest 

increases in population in the Southern and Western United States. However, growth rates from 

2000 to 2010 were not nearly as dramatic as in the 2000 census. Other factors related to stormwater 

discharge impacts also affect housing demand, such as the aesthetic quality of water bodies and the 

land adjacent to water bodies receiving runoff from C&D activity that may increase sediment 

loadings. Aesthetic degradation of land and water resources resulting from sediment and other 

pollutant discharges (e.g., increased water turbidity) have resulted in reduced market value of 

property. For example, a hedonic price study by Bejranonda et al. (1999) found that “the rate of 

sediment inflow entering the lakes has a negative influence on lakeside property rent” (p. 216) 

(USEPA, 2009b). 

Discharges from C&D activities can also negatively affect the quality and cost of providing 

drinking water. Sediment and other discharged pollutants adversely affect water quality, and require 

increased treatment expenditures such as settlement ponds, filtration, and chemical treatment. There 

also is the additional disposal cost of removing sludge that is created during the treatment process 

(USEPA 2007b). 

3.4.3 TRANSPORTATION

Increased sedimentation can lead to increased navigational difficulties and inefficiencies such as 

groundings and delays (Osterkamp et al. 1998). Shipping companies may switch to lighter loads or 

smaller vessels, which are generally less efficient. Removing sediment to keep navigable waterways 

passable requires dredging, which can be costly. The U.S. Army Corps of Engineers (USACE) 

spent more than $9 billion (2008$) from 1995 through 2008 to remove more the 2,600 million cubic 

yards of sediment to keep waterways passable (USACE 2009). EPA considered the possible 

impacts that increased waterway sedimentation resulting from C&D activities could have on 

navigable waterways. One of the most important considerations of sedimentation is the required 

dredging and removal of sediment to keep navigable waterways passable. The USACE spent more 

than $9 billion over 14 years and removed over 2,615 million cubic yards of sediment/material to 

dredge waterways and keep them passable (USACE 2009). 

3.4.5 CULTURAL RESOURCES 
Construction and Development NPDES General Permit Environmental Assessment 

37 

EPA is subject to Section 106 of the National Historic Preservation Act of 1966 and 1996 (NHPA; 

16 U.S.C 470). Under Section 106 of the National Historic Preservation Act and its implementing 

regulations at 36 CFR Part 800 and EO 11593, Federal agencies must take into account effects of 

their undertakings on historic properties listed on or eligible for listing on the National Register of 

Historic Places. Currently, more than 80,000 properties have been listed in the National Register. 

Together these records hold information on more than 1.4 million individual resources--buildings, 

sites, districts, structures, and objects. 

Additionally, the proposed action covers many of the tribal lands within the United States. Tribal 

lands in particular have unique cultural resources that are vulnerable to development and 

construction activities. EPA recognizes that local governments and tribal councils are the best 

source of identifying cultural resources within their communities. 

3.4.6 RECREATION

The Nation’s surface water resources — rivers, streams, lakes, ponds, reservoirs, estuaries, bays, 

and nearshore waters — are vitally important to the Nation’s recreational activities. These uses rely 

on, and are in part due to, the environmental health of our surface water resources. Polluted or 

sediment-laden water, however, greatly reduces the aesthetic appeal of a variety of recreational 

activities such as boating; skiing, boarding and tubing; swimming; diving; fishing; trapping; 

hunting; and outings to hike, jog, picnic, camp, and view natural resources and wildlife. Turbidity 

and suspended sediments are highly visible pollutants. Murky waters and odors are highly visible 

and notable detractions from the enjoyment gained through outdoor activities. Sedimentation in 

surface water bodies reduces their depth and thus their capacity for boating and swimming

(Osterkamp et al. 1998). Sedimentation and turbidity also can create dangers to boaters and water 

skiers, boarders, and tubers by concealing submerged hazards. 

Sediment-related nutrient loading can lead to algal blooms and oxygen-stressed waters that do not 

support higher value recreational and commercial fisheries. Sediment and other discharges from 

C&D sites also can greatly reduce fish populations by inhibiting reproduction and survival of an 

aquatic species (USEPA 2009b). Fish populations are important for subsistence anglers, 

commercial anglers and fish sellers, and consumers of fish and fish products. Recreational fishing is 

an important part of the US economy, generating more than $125 billion in economic output and 

more than one million American jobs. The economic contributions of recreational fishing have 

grown steadily over the last several decades (http://www.asafishing. 

org/statistics/saleco_trends/index.html). According to the American Sportfishing Association, there 

were nearly 40 million anglers in the United States in 2006. 

Table 3-3. Economic Contributions by Type of Fishing 

All Fishing Freshwater Saltwater Great Lakes 

Anglers, million 29.951. 23.04 8.53 1.51 

Expenditures/ Retail Sales 

($million) 45,335 31,182 11,051 2,524 

Total Multiplier Effect 

(Econ Output), ($million) 124,959 87,954 30,327 7,089 
Construction and Development NPDES General Permit Environmental Assessment 

38 

Salaries, Wages, and Business 

Earnings ($ million) 38,359 26,468 9,407 2,189 

Jobs 1,035,639 709,508 263,898 58,291 

Federal, Sates, and Local 

Taxes ($million) 116,359 11,495 4,017 910 

Source: American Sportfishing Association, 2008. Sportfishing in America, An Economic Engine and Conservation 

Powerhouse. January 2008. Online at: www.asafishing.org 1. Although there are 29.9 million anglers over the age of 16, the USFWS reports there are an additional 8.4 million youths aged 6-15 who fish, so the cited total number of anglers is nearly 40 million. 

 
Construction and Development NPDES General Permit Environmental Assessment 

39 

4. ENVIRONMENTAL CONSEQUENCES 

4.1 INTRODUCTION 

In discussing the environmental consequences of the proposed CGP, EPA is drawing a clear 

distinction between the CGP and the C&D Rule. NPDES regulations require the CGP to 

incorporate the requirements of the C&D Rule as a national, technology-based effluent limitation 

guideline for the construction and development point source industry. During the development and 

finalization of the C&D Rule, EPA assessed and evaluated the costs and benefits that derive from 

the C&D Rule. In the CGP, EPA is implementing the requirements of the C&D Rule. Thus, when 

considering the costs and benefits of issuing the proposed CGP, EPA attributes these costs and 

benefits to the technology-based requirements of the C&D Rule, and not to the issuance of the 

general permit, which is the Federal action triggering this NEPA review. 

In presenting the potential environmental impacts from the CGP, EPA points out the distinction 

between those that derive from, and are an inherent part of, the C&D Rule and those that are 

attributable to the CGP itself. An analysis of the requirements of the proposed CGP concluded that 

other than requirements included in the C&D Rule or the existing CGP, and other existing EPA 

regulations, the CGP has only one additional, new requirement: an increase in inspection frequency 

for some permittees and more detailed requirements regarding inspections during storm events 

causing discharge. From this new requirement, there is neither material cost nor immediate, direct 

environmental benefit. Thus in the remainder of this chapter, although environmental costs and 

benefits related to issuing the proposed CGP are discussed, these costs and benefits derive primarily 

from the incorporation and implementation of the C&D Rule, and are not directly attributable to 

the CGP itself. 

4.2 BASIS FOR COMPARISON OF ALTERNATIVES AND APPROACH TO 

ALTERNATIVES ANALYSIS 

The proposed CGP contains a number of changes in administrative, procedural, and reporting 

requirements. However, these changes are primarily intended to streamline and or clarify the 

requirements of the proposed CGP and are negligible factors in assessing the costs or environmental 

consequences of the proposed CGP. The new technical requirements of the proposed CGP derive 

overwhelmingly from the implementation of the C&D Rule. The costs and benefits of the C&D 

Rule were subject to extensive public review and comment from stakeholders and Federal and state 

agencies, and were considered and addressed in the promulgation of the final C&D Rule. 

However, implementation of the C&D Rule through the proposed CGP nonetheless represents a 

material change as compared to the requirements of the current CGP. These changes are substantial 

enough that ignoring the environmental impacts, costs, and benefits of the C&D Rule is 

inappropriate in the context of performing a NEPA review of this Federal action. In preparing this 

EA for the proposed CGP, EPA has relied on the data collection, review, and analyses performed 

by the Agency in developing the C&D Rule. EPA considers its reliance on the C&D rulemaking 

record a valid approach to performing a NEPA review of the environmental impacts of the 

proposed CGP in this EA. 

4.2.1 BACKGROUND ON THE C&D RULE

The C&D Rule considered four regulatory options in the development of the final Rule. For the 

baseline (i.e., then current conditions) and each regulatory option, EPA performed a series of 

analyses. EPA estimated technology-based reductions in sediment discharges from constructions 
Construction and Development NPDES General Permit Environmental Assessment 

40 

sites, relative to baseline, as described in Development Document for the final Rule (USEPA 

2009a). EPA estimated changes in in-stream sediment and nutrient concentrations accruing from 

these reductions in sediment loadings, relative to baseline, to estimate environmental benefits as 

described in the Benefits Assessment for the final rule (USEPA 2009b). EPA also estimated the 

compliance costs to the industry to achieve these reductions in sediment loadings, relative to 

baseline, as described in Economic Assessment for the final rule (USEPA 2009c).

EPA selected the technologies described under Option 1 as the BPT level of control for toxic 

pollutants and BCT level of control for conventional pollutants. EPA made this selection because 

the specified nonnumeric requirements of Option 1 represent a level of control that is 

technologically available and economically practicable and represents the average of the best 

performance of construction sites in the C&D industry. For national, technology-based pollution 

control, EPA selected Option 4 as the basis for both BAT and NSPS because the requirements of 

Option 4 were demonstrated to be technologically available, economically achievable, pose no 

barrier to entry, and have acceptable non-water quality environmental impacts. 

Subsequent to promulgation of the final C&D Rule, several petitioners submitted comments on the 

appropriateness of the data analysis that EPA used to derive the numeric turbidity limits. Upon 

review of the submitted comments, EPA agreed that the data and analysis performed in the 

development of the final numeric limit did not support the final limit. EPA has stayed 

implementation of the numeric turbidity limit portion of the rule pending its re-analysis. 

Option 4 has identical requirements for BAT and NSPS. Thus, the practical effect of the final C&D 

Rule is that NSPS is the industry standard of performance for stormwater runoff from C&D sites. 

One reason is that all sites, whether existing or new sources, are required to meet BAT limitations. 

A second reason is that is the majority of C&D industry projects are of a relatively short-term 

nature, with a median project duration of 9.4 months6

. 

Over the anticipated life of the proposed CGP (5 years from issuance), EPA NOI application data 

indicate that existing sources will decrease from a range of 4% - 8% in 2013 to approximately 1% 

by 2017 (see Table 2-1). Thus, EPA has determined that for the purposes of this NEPA review all 

C&D industry activity is from new sources and, therefore, the EA only discusses the results of 

EPA’s analyses for Option 4 of the C&D Rule as relevant to potential environmental consequences. 

4.2.2 APPROACH TO THE COMPARISON OF ALTERNATIVES

The C&D Rule developed national, industry-wide estimates of pollutant reductions, compliance 

costs, and benefits to assess the impacts of a national effluent limitations guideline rulemaking. In 

contrast, the proposed CGP only covers a small portion of C&D industry activity, defined by the 

scope of coverage of the proposed CGP. Thus, the EA presents an analysis of impacts based on the 

estimated C&D activity projected to be covered under the proposed CGP, i.e., only affecting C&D 

activities in four states, the District of Columbia, US territories, Indian lands, and some Federal 

lands. The qualitative impacts of the CGP and C&D Rule are identical; they only differ 

quantitatively. 

To review the potential environmental consequence of the proposed CGP, EPA has disaggregated 

the C&D activity for the proposed CGP from the national-level assessments developed for the C&D 

Rule. To determine the portion of C&D activity covered under the proposed CGP, EPA compared 

 

6

 Based on an analysis of data from 46,740 available NOI applications. 
Construction and Development NPDES General Permit Environmental Assessment 

41 

the C&D activity under the existing CGP, based on data from CGP NOI applications submitted to 

EPA to the national estimate of C&D activity developed in the economic assessment for the C&D 

Rule (Table 4-1). The annual number of NOI applications was obtained from EPA’s eNOI database 

covering the period 2004 through 2011. Because the C&D Rule economic assessment analyses 

were normalized to 2008 dollars, EPA used the NOI data for 2008 for comparison to the C&D Rule 

assessments. 

The economic assessment for the C&D Rule projected a national C&D industry activity of 128,536 

projects; and the C&D activity covered under the existing CGP covering essentially the same year 

totaled 5,960 projects, or 4.6% of the national C&D activity. There is about a two-fold difference in 

annual activity between 2004 and 2011, ranging from 3,730 to 7,316 projects. However, the 8-year 

average activity is 5,846 projects, nearly identical to the projects reported in 2008. To maintain the 

consistency for this analysis, EPA is using the figures from 2008, and an estimated percentage of 

CGP C&D activity of 4.5% of total national C&D activity, applied to the projected benefits and 

costs presented in the C&D Rule national assessment to estimate CGP impacts. 

4.3 IMPLEMENTATION OF BEST MANAGEMENT PRACTICES (BMP’s) 

Construction site operators comply with the CGP through the implementation of variety of Best 

Management Practices (BMPs) which minimize the discharge of pollutants from construction site 

stormwater discharges when selected, implemented, and managed as intended. Construction site 

operators have the discretion of choosing the BMPs that meet the requirements of the permit and of 

their project. While the CGP does not dictate that any specific BMP be installed on a site; operators 

must meet both non-numeric and water quality-based effluent limitations to gain coverage under the 

CGP which includes meeting restrictions on erosion and sediment controls, pollution prevention, 

and site stabilization as required by the C & D rule. Therefore, through implementation of BMP’s 

Table 4-1. eNOI Statistics on C&D Industry Applications Under the Existing CGP 

Year No. NOI Applications 

2004 5,293 

2005 7,316 

2006 6,392 

2007 6,091 

2008 5,960 (4.6%) 

2009 5,091 

2010 4,778 

20111 3,730 

Average, 2004-2010 5,846 (4.5%) 

National Total C&D Activity2 2008 128,536 

1. The projected number is based on NOI applications through June 30, 2011, prorated to 49% (the average 

percentage of applications submitted from January 1 through June 30, 2004-2010). 

Source: EPA 2009c
Construction and Development NPDES General Permit Environmental Assessment 

42 

by operators, the adverse environmental and socio-economic impacts to resources discussed 

throughout this chapter are minimized. 

There are five categories of stormwater BMPs for construction activities. These are listed at: 

http://cfpub.epa.gov/npdes/stormwater/menuofbmps/index.cfm?action=min_measure&min_

measure_id=4. These include: construction site planning and management, erosion control, runoff 

control, sediment control and good housekeeping/materials management. The information EPA 

presents for each stormwater BMP generally includes, with some exceptions: a description, 

applicability, siting/design considerations, limitations, maintenance considerations effectiveness, 

and cost considerations. This information also includes potential adverse environmental effects 

related to the BMP. This information on listed construction site stormwater BMPs is summarized 

below. 

4.3.1    Construction Site Planning and Management  

Construction sequencing is a specified work schedule that coordinates the timing of landdisturbing activities and the installation of erosion and sediment control measures to reduce on-site 

erosion and off-site sedimentation by performing land-disturbing activities and installing control 

practices according to a planned schedule (Smolen et al. 1988). Construction site phasing involves 

disturbing only part of a site at a given time to prevent erosion from dormant areas; site phasing 

needs to be considered early in overall site planning. Construction sequencing can be used to plan 

earthwork and erosion/sediment control activities where land disturbance may affect water quality 

in a receiving waterbody. The erosion and sediment control plan should state the proposed 

schedule and a protocol to make changes for unforeseen problems. 

Construction sequencing can be an effective tool for erosion and sediment control because it 

ensures that management practices are installed where necessary and when appropriate. Flexibility 

allows for updating the plan to maximize the effectiveness of erosions and sediment control BMPs 

under changing conditions. A comparison of sediment loss from a typical development and from a 

comparable phased project showed a 42 percent reduction in sediment export in the phased project 

(Claytor 1997). 

Construction Site Operator BMP Inspections and Maintenance are essential to managing 

construction site stormwater runoff. Three types of BMP inspections are performed: routine 

inspections and inspections performed before and after rain events. Routine inspections are integral 

parts of regular maintenance activities to ensure the integrity and effectiveness of BMPs and to 

observe whether site conditions have changed and rendered initial BMP designs inadequate. 

Awareness and education of general soil and sediment controls through this BMP expedites the 

repair and maintenance efforts by raising issues early. 

Land Grading involves reshaping the ground surface to planned grades as determined by an 

engineering survey, evaluation, and layout. Land grading provides more suitable topography for 

buildings, facilities, and other land uses and helps to control surface runoff, soil erosion, and 

sedimentation during and after construction. Land grading is applicable to sites with uneven or 

steep topography or easily erodible soils, because it stabilizes slopes and decreases runoff velocity. 

Grading activities should maximally maintain existing drainage patterns. Land grading is a key 

consideration for Construction Sequencing. Improper grading practices can disrupt natural 
Construction and Development NPDES General Permit Environmental Assessment 

43 

stormwater patterns and lead to poor drainage, high-runoff velocities, and increased peak flows 

during storm events. Clearing and grading the entire site without vegetated buffers promotes offsite 

transport of sediments and other pollutants. However, land grading is an effective way to reduce 

steep slopes and stabilize highly erodible soils when properly implemented with stormwater 

management and erosion and sediment control practices. 

Preserving Natural Vegetation protects desirable trees, vines, bushes, and grasses from damage 

during site development. Vegetation provides erosion control, stormwater detention, biofiltration, 

and adds aesthetic values during and after construction activities. Preserving natural vegetation is 

applicable where predevelopment vegetation exists. The practice can be especially beneficial for 

floodplains, wetlands, stream banks, steep slopes, and other areas where erosion controls would be 

difficult to establish, install, or maintain. Natural vegetation (existing trees, vines, brushes, and 

grasses) can provide water quality benefits by intercepting rainfall, filtering stormwater runoff, and 

preventing sediments and other pollutants from leaving the site. 

4.3.2 Erosion Control 

Chemical Stabilizers (soil binders or soil palliatives) provide temporary soil stabilization to reduce 

soil erosion from runoff and wind where vegetation cannot be established, and provide immediate 

protection. Chemical stabilizers are used alone, where other stabilization methods are ineffective 

due to environmental constraints, or used along with vegetative or perimeter practices to enhance 

erosion/sediment control. Chemical stabilization is usually more expensive than vegetative 

practices. In general, the effectiveness of polymer stabilization methods ranges from 70 percent to 

90 percent. The effectiveness of a polymer depends on soil type, application method, and the 

polymer's individual chemical characteristics (Aicardo 1996). 

Compost Blankets are a layer of loosely applied compost or composted material, placed on soil in 

disturbed areas to control erosion and retain sediment due to sheet-flow runoff. These blankets 

prevent stormwater erosion by presenting a more permeable surface to oncoming sheet flow and 

facilitating infiltration; by filling in small rills and voids to limit channelized flow; and by 

promoting establishment of surface vegetation. Compost blankets can be placed on any soil surface: 

rocky, frozen, flat, or steep and are made from a variety of feedstocks, including municipal yard 

trimmings, food residuals, separated municipal solid waste, biosolids, and manure. Advantages 

provided by compost blankets include the following (Alexander 2003; Faucette 2004): 

• The compost retains a large volume of water, which helps reduce runoff, prevents or reduces 

sheet and rill erosion, and aids in establishing vegetation in the blanket. 

• The compost blanket acts as a buffer to absorb rainfall energy, which prevents soil 

compaction and crusting and facilitates rainfall infiltration. 

• Compost blankets facilitate plant growth by capturing and retaining moisture and providing 

a suitable microclimate and nutrients for seed germination. 

• The compost stimulates microbial activity, which increases decomposition of organic 

matter, increases nutrient availability for plants, and improves the soil structure. 

• Compost can remove pollutants, such as heavy metals; nitrogen; phosphorus; oil and grease; 

and fuel, from stormwater, thus improving downstream water quality (W&H Pacific 1993; 

USEPA 1998). 
Construction and Development NPDES General Permit Environmental Assessment 

44 

Numerous studies conducted by a variety of universities and State DOTs have reported the 

effectiveness of compost blankets. A University of Georgia research trial (Faucette and Risse 2002) 

reported that correctly applied compost blankets provide almost 100 percent soil surface coverage, 

while other methods (e.g., straw mats and mulches) provide only 70 to 75 percent coverage. 

Uniform soil cover by the compost blanket is a key component to effective erosion and sediment 

control because it helps maintain sheet flow and prevents stormwater from forming rills under the 

blanket. Compost blankets also help protect the structural stability of the slope, particularly when 

vegetated. 

An Iowa State University study (Glanville et al. 2003), sponsored by the Iowa Department of 

Natural Resources and Iowa DOT, compared compost-treated road embankments to conventionally 

treated embankments (i.e., topsoil added to surface). The results showed that the 2- and 4-inch thick 

compost blankets reduced runoff from the embankment by 80 percent. The erosion rate from the 

compost blanket was less than 1 percent of that from the non-composted areas, and weed growth on 

compost-treated areas was approximately 25 percent of that on untreated areas. 

Dust Control BMPs reduce surface activities and air movement that generate dust from disturbed 

soil surfaces. Dust control measures at a site depend on site topography and land cover, site soil 

characteristics, and rainfall. Earthmoving activities are the major source of dust from construction 

sites, but traffic and general disturbances can also be major contributors (WA Dept. of Ecology 

1992). Construction sequencing and disturbing only small areas at a time can greatly reduce dust 

from a site. Control measures and design criteria include: sprinkling/irrigation; vegetative cover; 

mulching; wind breaks; deep tillage; stone; and spray-on chemical soil treatments. 

The effectiveness of various dust control BMP’s include: 

• Mulch. Can reduce wind erosion by up to 80 percent. 

• Wind Breaks/Barriers. For each foot of vertical height, an 8- to 10-foot deposition zone 

develops on the leeward side of the barrier. The permeability of the barrier will change its 

effectiveness at capturing windborne sediment. 

• Tillage. Roughening the soil can reduce soil losses by approximately 80 percent in some 

situations. 

• Stone. The size of the stones can affect the amount of erosion to take place. In areas of high 

wind, small stones are not as effective as 20 cm stones. 

• Spray-on Chemical Soil Treatments (palliatives). Effectiveness of polymer stabilization 

methods range from 70 percent to 90 percent. 

 

Geotextiles are porous fabrics also known as filter fabrics, road rugs, synthetic fabrics, construction 

fabrics, or simply fabrics. Geotextiles are used for many purposes, e.g., separators, reinforcement, 

filtration and drainage, and erosion control (USEPA 1992). Geotextiles can aid plant growth by 

holding seeds, fertilizers, and topsoil in place. Fabrics are made to match specific site needs and are 

relatively inexpensive for some applications. Geotextiles can be used in various ways for erosion 

control on construction sites. Use them as matting to stabilize the flow of channels or swales or to 

protect seedlings on recently planted slopes until they become established. Use matting on tidal or 

stream banks, where moving water is likely to wash out new plantings. Geotextiles can be used to 

protect exposed soils immediately and temporarily, such as when active piles of soil are left 
Construction and Development NPDES General Permit Environmental Assessment 

45 

overnight. They can also be used as a separator between riprap and soil, which prevents the soil 

from being eroded from beneath the riprap and maintains the riprap's base. 

Gradient Terraces are earthen embankments or ridge and channel systems that reduce erosion by 

slowing, collecting and redistributing surface runoff to stable outlets that increase the distance of 

overland runoff flow. Terraces hold moisture and help trap sediments, minimizing sediment-laden 

runoff. Gradient terraces are most effective in barren areas with an existing or expected water 

erosion problem. They are effective only if suitable runoff outlets are available, e.g., grassed 

waterways, vegetated areas, or tile outlets. 

Mulching is an erosion control practice using materials such as grass, hay, wood chips, wood 

fibers, straw, or gravel to stabilize exposed or recently planted soil surfaces. Mulching is highly 

recommended and most effective used along with vegetation, although it is often used where 

vegetation cannot be established. In addition to soil stabilization, mulching can reduce stormwater 

velocity and improve the infiltration. Mulching can aid plant growth by holding seeds, fertilizers, 

and topsoil in place; preventing birds from eating seeds; retaining moisture; and insulating plant 

roots. Mulching effectiveness varies according to the type of mulch used. Soil loss reduction for 

different mulches ranges from 53 to 99.8 percent. Water velocity reductions range from 24 to 78 

percent (Harding 1990). 

Riprap is a layer of large stones used to protect soil from erosion in areas of concentrated runoff. 

Riprap can also be used on slopes that are unstable because of seepage problems. Riprap stabilizes 

cut-and-fill slopes; channel side slopes and bottoms; inlets and outlets for culverts, bridges, slope 

drains, grade stabilization structures, and storm drains; and stream banks and grades. Steep slopes 

limit the applicability of riprap: slopes greater than 2:1 can cause riprap loss from erosion and 

sliding and if used improperly, can increase erosion. 

Seeding is used to control runoff and erosion on disturbed areas by establishing perennial 

vegetative cover. It reduces erosion and sediment loss and provides permanent stabilization. 

Seeding is economical and adaptable to different site conditions, allowing selection of a variety of 

plant materials. Perennial vegetative cover from seeding has been shown to remove between 50 

and 100 percent of total suspended solids from stormwater runoff, with an average removal of 90 

percent (USEPA 1993). The effectiveness of seeding can be limited by high erosion during 

establishment, the need to reseed areas that fail to establish, limited seeding times, or unstable soil 

temperature and soil moisture content during germination and early growth. Seeding does not 

immediately stabilize soils, thus requiring temporary erosion and sediment control measures to 

prevent pollutants from disturbed areas from being transported off the site. 

Sodding is a permanent erosion control practice and involves laying a continuous cover of grass sod 

on exposed soils. Sodding stabilizes disturbed areas and reduces stormwater runoff velocity. 

Sodding is useful for any graded or cleared area that may erode or requires immediate vegetative 

cover or stabilize channels or swales that convey concentrated flows and reduce flow velocities. 

Sod removes up to 99 percent of total suspended solids in runoff, but its sediment trapping 

efficiency is highly variable depending on hydrologic, hydraulic, vegetation, and sediment 

characteristics. 
Construction and Development NPDES General Permit Environmental Assessment 

46 

Soil Retention measures are structures or practices that hold soil in place or keep it contained 

within a site boundary. They include grading or reshaping the ground to lessen steep slopes or 

shoring excavated areas with wood, concrete, or steel structures. Some soil-retaining measures are 

used only for erosion control; others are also used to protect workers during excavations. When 

sites have very steep slopes or loose, highly erodible soils that render other methods ineffective, 

reinforced soil-retaining structures are used. Soil-retention structures, if properly designed and 

installed, can effectively prevent erosion in areas with steep slopes and erodible soils. The potential 

for failure depends on the design, installation, and maintenance of the structures, and the likelihood 

of catastrophic events such as heavy rains, earthquakes, and landslides. 

Soil Roughening is a temporary erosion control practice often used with grading. Soil roughening 

increases the relief of bare soil surfaces with horizontal grooves by stair-stepping (parallel to soil 

contours) or tracking with construction equipment. Slopes left in a roughened condition or not fine 

graded can also reduce erosion. It reduces runoff velocity, increases infiltration, reduces erosion, 

traps sediment, and prepares the soil for seeding and planting by giving seed an opportunity to take 

hold and grow. 

Temporary Slope Drains are flexible, temporary conduits for stormwater that extend the length of a 

disturbed slope to eliminate gully erosion from concentrated flows and divert flow. Constructing 

and removing more permanent drains usually disturb the surrounding area; erosion and downstream 

soil movement often occur. Temporary slope drains, also called pipe slope drains, convey runoff 

without causing erosion on or at the bottom of the slope. They are used during grading until 

permanent drainage structures are installed and slopes permanently stabilized. Temporary slope 

drains can be used on most disturbed slopes. 

Temporary stream crossings provide for safe, stable construction vehicle traffic crossing of 

watercourses. Temporary stream crossings provide stream bank stabilization, reduce the risk of 

damage to the streambed or channel, and minimize sediment loading from construction traffic. 

Culverts obstruct stream flows, interfere with migrating fish, and are vulnerable to washout. 

Excavating the streambed and approach to lay riprap or other stabilization material causes major 

stream disturbance, with mud and other debris transported directly into the stream unless conducted 

only during periods of low flow. 

Sand Fences are barriers made of small, evenly spaced wooden slats or fabric, erected to reduce 

wind velocity and to trap blowing sand. Sand fences can be used as perimeter controls around open 

construction sites to keep sediments from being blown offsite. They prevent offsite damage to 

roads, streams, and adjacent properties. Wind fences are appropriate on areas with loose, finetextured soils that can be transported offsite by winds. The spaces between the fence slats allow 

wind and sediment to pass through but reduce the wind's speed, causing sediment to deposit along 

the fence. 

4.3.3 Runoff Control 

Check Dams are relatively small, temporary structures constructed across a swale or channel. They 

slow the velocity of concentrated water flows, reducing erosion. As stormwater runoff flows 

through the channel, check dams catch sediment from the channel itself or the contributing drainage 

area. They are typically constructed out of gravel, rock, sandbags, logs or treated lumber, or straw 
Construction and Development NPDES General Permit Environmental Assessment 

47 

bales and are most effective when used with other stormwater, erosion, and sediment-control 

measures. Field experience has shown that rock check dams are more effective than silt fences or 

straw bales to stabilize wet-weather ditches (VDCR 1995). For long channels, check dams are most 

effective when used in a series, creating multiple barriers to sediment-laden runoff. 

Grass-lined Channels convey stormwater runoff through a stable conduit and slow concentrated 

runoff through vegetation lining the channel. Grassed channels are not usually designed for peak 

runoff control by themselves but are often used with other BMPs (e.g., subsurface drains; riprap 

stabilization). On moderately steep slopes needing drainage, grassed channels can include 

excavated depressions or check dams for enhanced runoff storage, decreased flow rates, and 

improved pollutant removal, or by temporarily retaining runoff in the channel. Pollutants can be 

removed from stormwater by filtration through vegetation, by deposition, or in some cases by 

infiltration of soluble nutrients into the soil. The degree of pollutant removal in a channel depends 

on how long the water stays in the channel and the amount of contact with vegetation and the soil 

surface. 

Permanent Slope Diversions are designed to transport runoff down slopes in a way that minimizes 

potential erosion. Diversions are constructed by creating channels laterally across slopes to 

intercept down-slope runoff flows. Channels have supporting earthen ridges on the bottom sides to 

reduce slope length, collect stormwater runoff, and deflect runoff to outlets that won’t cause 

erosion. Diversions can also promote vegetation growth by redirecting flows while vegetation 

becomes established. Diversions should be where uncontrolled runoff may cause property damage 

from erosion or resulting sedimentation. 

Temporary Diversion Dikes are earthen perimeter controls consisting of a ridge of compacted soil, 

often accompanied by a ditch or swale with a vegetated lining. They occur at the top or base of a 

sloping disturbed area or along and within the perimeter of the disturbed part of a site. They are also 

called earth dikes or interceptor dikes. They all serve to control the velocity and/or route of 

sediment-laden stormwater runoff. Dikes are effective at diverting sediment-laden stormwater 

runoff around a disturbed area; however, concentrated channel runoff has increased erosion 

potential. 

4.3.4 Sediment Control 

Brush Barriers are perimeter sediment control structures constructed of material from site clearing 

and grubbing, e.g., small tree branches, root mats, stone, or other debris. Brush barriers can be 

covered with filter cloth to stabilize the structure and improve barrier efficiency. Brush barriers 

provide temporary storage for large amounts of cleared material from a site, however, this material 

should be removed after construction activities cease and the site is stabilized. Brush barriers can 

be effective at reducing offsite sediment transport, and their effectiveness is greatly increased with 

the use of a fabric cover on the up-slope side of the brush barrier. 

Compost Filter Berms are dikes of compost or a compost product, placed perpendicular to sheet 

flow runoff to control erosion in disturbed areas and retain sediment. They are used in place of 

traditional sediment and erosion controls, such as a silt fence or straw bale barrier. The compost 

filter berm is trapezoidal in cross section, and provides a three-dimensional filter that retains 

sediment and other pollutants while allowing cleaned water to flow through. A compost filter berm 
Construction and Development NPDES General Permit Environmental Assessment 

48 

can be used as a check dam in small drainage ditches. Using compost in the berm provides 

additional benefits, including the retention of large volumes of water, sediments, and pollutants that 

improve water quality downstream and reduce erosion. Nutrients and hydrocarbons trapped by 

compost filters can be naturally cycled and decomposed through bioremediation by microorganisms 

commonly found in the compost matrix (USEPA 1998). A study conducted in Portland, Oregon 

(W&H Pacific 1993) compared the effectiveness of a silt fence and a mixed yard debris compost 

filter berm to a control plot during five storm events. The study found that the filter berm was over 

90 percent effective in removing settleable and total suspended solids when compared to the control 

plot and was approximately 66 percent more effective than the silt fence. Another quantitative 

study performed by the Snohomish County, Washington, Department of Planning and Development 

Services (Caine 2001) showed no decrease in turbidity with a silt fence but a 67 percent reduction 

in turbidity using a compost filter berm. 

Compost Filter Socks are a contained compost filter berm. They are mesh tubes filled with 

composted material, placed perpendicular to sheet-flow runoff. The compost filter sock provides a 

three-dimensional filter that retains sediment and other pollutants while allowing cleaned water to 

flow through (Tyler and Faucette 2005). Filter socks are used in place of traditional sediment and 

erosion controls such as a silt fence because: installation does not require disturbing the soil surface 

which reduces erosion, it is easily removed and the operator must dispose of only a relatively small 

volume of material (the mesh). Filter socks, due to their flexibility, are especially useful on steep or 

rocky slopes where installation of other erosion control tools is not feasible. In addition to retaining 

sediment, compost can retain pollutants and improve the downstream water quality. Absorbed 

and/or trapped nutrients or pollutants can be naturally cycled and decomposed through 

bioremediation by microorganisms commonly found in the compost matrix. 

A large number of qualitative studies have reported the effectiveness of compost filter socks in 

removing settleable solids and total suspended solids from stormwater (McCoy 2005; Tyler and 

Faucette 2005). These studies have consistently shown that compost filter socks are at least as 

effective as traditional erosion and sediment control BMPs and often are more effective. Compost 

filter socks are often used in conjunction with compost blankets to form a stormwater management 

system. Together, these two BMPs retain a very high volume of stormwater, sediment, and other 

pollutants. The compost in the filter sock can also improve water quality by absorbing various 

organic and inorganic contaminants from stormwater, including motor oil. Tyler and Faucette 

(2005) conducted a laboratory test using 13 types of compost in filter socks. They found that half of 

the compost filter socks removed 100 percent of the motor oil introduced into the simulated 

stormwater and the remaining compost filter socks removed over 85 percent of the motor oil from 

the stormwater. 

Construction Entrance Stabilization serves to minimize the amount of sediment leaving the area as 

mud/ sediment attached to vehicles. Installing a pad of gravel over filter cloth where construction 

traffic leaves a site helps stabilize a construction entrance and removes mud/sediment from the 

wheels, reducing soil offsite transport. The filter cloth separates gravel from the soil below so 

gravel isn’t ground into the soil and reduces rutting caused by vehicle tires by spreading the 

vehicle's weight over a soil area larger than the tire width. Site entrance stabilization should be used 

at any roadway or where vehicles enter or leave the site and should be in place before construction 

and further site disturbance begin. 
Construction and Development NPDES General Permit Environmental Assessment 

49 

Fiber Rolls (also called fiber logs or straw wattles) are tube-shaped erosion-control devices filled 

with straw, flax, rice, coconut fiber material, or composted material. Each roll is wrapped with UVdegradable polypropylene netting for longevity or with 100% biodegradable materials like burlap, 

jute, or coir. Fiber rolls complement permanent BMPs for source control and re-vegetation. When 

installed in combination with straw mulch, erosion control blankets, hydraulic mulches, or bounded 

fiber matrices for slope stabilization, these devices reduce the effects of long or steep slopes. Fiber 

rolls also help to slow, filter, and spread overland flows, which helps prevent erosion and minimizes 

rill and gully development. Fiber rolls also help reduce sediment loads to receiving waters by 

filtering runoff and capturing sediments. 

Unlike other BMPs that could cause water to back up and flow around the edges, fiber rolls allow 

water to flow through while capturing runoff sediments. Fiber rolls placed along the shorelines of 

lakes and ponds provide immediate protection by dissipating the erosive force of small waves. As 

an alternative to silt fences, fiber rolls have some distinct advantages, including the following 

(Earth Saver 2005): 

• They install more easily, particularly in shallow soils and rocky material. 

• They are more adaptable to slope applications and contour installations than other erosion 

and sediment control practices. 

• They are readily molded to fit the bank line. 

• They blend in with the landscape and are less obtrusive than other erosion and sediment 

controls such as silt fence. 

• They do not obstruct hydraulic mulch and seed applications. 

• They can be removed or left in place after vegetation is established. 

Fiber rolls can provide slope protection for 3 to 5 years (California Straw Works 2005). They 

slowly decompose into mulch, and the netting breaks down into small pieces. The San Diego State 

University Soil Erosion Research Laboratory reported that the use of fiber roll products reduced 

offsite sediment delivery by 58 percent (International Erosion Control Association 2005). 

Gravel or Stone Filter Berms are temporary ridges made of loose gravel, stone, or crushed rock. 

They slow and filter flow and divert it from open traffic areas and are considered an efficient form 

of sediment control. One type of filter berm is the continuous berm, a geosynthetic fabric berm that 

captures sand, rock, and soil. Gravel or stone filter berms are most suitable in areas where traffic 

needs to be rerouted because roads are under construction, or in traffic areas within a construction 

site. Berms are intended to be used only in gently sloping (<10%) areas. The effectiveness has 

been rated at up to 95 percent for sediment removal and depends on local conditions such as 

hydrologic, hydraulic, topographic, and sediment characteristics. 

Sediment Basins and Rock Dams can be used to capture sediment from stormwater runoff before it 

leaves a construction site. Both structures allow a pool to form in an excavated or natural 

depression, where sediment can settle. The pool is dewatered through a single riser and drainage 

hole leading to a suitable downstream outlet or through the gravel of a rock dam, releasing water 

more slowly than without the control structure. A sediment basin is constructed by excavation or 

erecting an earthen embankment across a low area or drainage swale. Some sediment basins are 
Construction and Development NPDES General Permit Environmental Assessment 

50 

designed to drain completely during dry periods while others retain a shallow pool of water 

between storm events. Rock dams are similar to sediment basins with earthen embankments except 

constructed of rock and gravel. They release water from the settling pool gradually through the 

spaces between the rocks. 

The effectiveness of a sediment basin depends primarily on the sediment particle size and the ratio 

of basin surface area to inflow rate (Smolen et al. 1988). Basins with a large surface area-to-volume 

ratio are the most effective. USEPA (1993) estimates an average total suspended solids removal 

rate for all sediment basins of 55 percent to 100 percent with an average effectiveness of 70 percent. 

Sediment Filter Systems and Chambers can be confined or unconfined, on-line or off-line, and 

aboveground or belowground. Confined sediment filters are constructed with the filter medium 

contained in a structure, often a concrete vault. Unconfined sediment filters are made without a 

confining structure. On-line systems retain stormwater in its original stream channel or storm drain 

system. Off-line systems divert stormwater. Sediment filters are usually limited to removing 

pollutants from stormwater runoff. 

Treatment effectiveness depends on factors like treatment volume; whether the filter is on-line or 

off-line, confined or unconfined; and the type of land use in the contributing drainage area. 

MWCOG (1992) states that sand filter removal rates are "high" for sediment and trace metals and 

"moderate" for nutrients, biochemical oxygen demand, and fecal coliform bacteria. Removal rates 

can be increased slightly by using a peat/sand mixture as the medium because peat has adsorptive 

properties (pollutants attach to it) (MWCOG, 1992). The estimated pollutant removal capabilities 

for various filter systems are shown below: 

Pollutant removal efficiencies for sand filters 

Source

Filter 

system

TSSa

(%)

TPa

(%)

TNa

(%)

Other 

pollutants

Claytor and 

Schueler, 

1996 

Surface sand 

filter 85 55 35 

Bacteria: 

40%-80% 

Metals: 35%-

90% 

Perimeter 

sand filter 80 65 45 Hydrocarbons: 80% 

Livingston, 

1997 

Sand filter 

(general) 60-85 30-75 30-60 Metals: 30%-80% a

TSS=total suspended solids; TP=total phosphorus; TN=total nitrogen. 

Sediment Traps are small impoundments that allow sediment to settle out of construction runoff. 

They are usually installed in a drainage way or other point of discharge from a disturbed area. 

Temporary diversions can be used to direct runoff to the sediment trap (USEPA 1993). Sediment 

traps detain sediments in stormwater runoff to protect receiving streams, lakes, drainage systems, 

and the surrounding area. Sediment traps are commonly used at the outlets of stormwater diversion 

structures, channels, slope drains, construction site entrance wash racks, or any other runoff 

conveyance that discharges waters containing sediment and debris. Although sediment traps allow 
Construction and Development NPDES General Permit Environmental Assessment 

51 

eroded soils to settle, their detention periods are too short for removing fine particles like silts and 

clays. 

Sediment trapping efficiency is a function of surface area and peak inflow rate (Smolen et al. 1988). 

Traps that provide pools with large length-to-width ratios have a greater chance of success. 

Sediment traps have a useful life of about 18 to 24 months (USEPA 1993), but their effectiveness 

depends on the amount and intensity of rainfall and erosion, and proper maintenance. USEPA 

(1993) estimates an average total suspended solids removal rate of 60 percent. 

Silt Fences are used as temporary perimeter controls around sites where construction activities will 

disturb the soil and apply to construction sites with relatively small drainage areas. Silt fences 

consist of a length of filter fabric stretched between anchoring posts spaced at regular intervals 

along the site at low/downslope areas. The filter fabric should be entrenched in the ground between 

the support posts. When installed correctly and inspected frequently, silt fences can be an effective 

barrier to sediment leaving the site in stormwater runoff. 

USEPA (1993) reports the following effectiveness ranges for silt fences constructed of filter fabric 

that are properly installed and well maintained: average total suspended solids removal of 70 

percent, sand removal of 80 to 90 percent, silt-loam removal of 50 to 80 percent, and silt-clay-loam 

removal of 0 to 20 percent. Removal rates are highly dependent on local conditions and 

installation. 

Storm Drain Inlet Protection measures prevent soil and debris from entering storm drain drop 

inlets and are usually temporary and implemented before a site is disturbed. Inlet protection can be: 

excavating around the perimeter of the drop inlet; fabric barriers around inlets; and block and gravel 

protection. Sandbags also are used to create temporary sediment barriers at inlets. Excavated drop 

inlet protection can be used to improve the effectiveness and reliability of other sediment traps and 

barriers, such as fabric or block and gravel inlet protection. The effectiveness of inlet protection 

alone is low for erosion and sediment control, long-term pollutant removal, and habitat and stream 

protection. 

Straw or Hay Bales have historically been used on construction sites for erosion and sediment 

control as check dams, inlet protection, outlet protection, and perimeter control. Many applications 

of straw bales for erosion and sediment control are proving ineffective due to the nature of straw 

bales degrading and rotting, inappropriate placement, inadequate installation, or a combination of 

all three factors (Fifeld 1999). Since many applications of straw and hay bales have been 

ineffective, EPA recommends that other BMP options are considered such as silt fences, rock check 

dams, fiber rolls, compost blankets or gravel bags. 

Vegetated Buffers are areas of natural or established vegetation maintained to protect water quality 

of neighboring areas. Buffer zones slow stormwater runoff, provide an area where runoff can 

permeate the soil, contribute to ground water recharge, and filter sediment. Slowing runoff helps 

prevent soil erosion and stream bank collapse. Several studies indicate greater than 90 percent 

reductions in sediment and nitrate concentrations when vegetated buffers are used. Buffer/filter 

strips do a reasonably good job of removing phosphorus attached to sediment, but they are not so 

effective at removing dissolved phosphorus (Gilliam 1994). 
Construction and Development NPDES General Permit Environmental Assessment 

52 

4.3.5 Good Housekeeping/Materials Management 

Concrete Washouts are used to contain concrete and liquids when the chutes of concrete mixers 

and hoppers of concrete pumps are rinsed out after delivery. The washout facilities consolidate 

solids for easier disposal and prevent runoff of liquids. The wash water is alkaline and contains high 

levels of chromium, which can leach into the ground and contaminate groundwater. It can also 

migrate to a storm drain, which can increase the pH of area waters and harm aquatic life. Solids that 

are improperly disposed of can clog storm drain pipes and cause flooding. Installing concrete 

washout facilities not only prevents pollution but also is a matter of good housekeeping at your 

construction site. 

General Construction Site Wastes must be properly managed and disposed of to reduce the risk of 

pollution from materials such as surplus or refuse building materials or hazardous wastes. Practices 

such as trash disposal, recycling, proper material handling, and spill prevention and cleanup 

measures can reduce the potential for stormwater runoff to mobilize construction site wastes and 

contaminate surface or ground water. Handle all solid wastes, hazardous materials and wastes, 

pesticides and fertilizers, petroleum products and detergents accordingly. The only way to be sure 

that waste management practices are being followed is to be aware of worker habits and to inspect 

storage areas regularly. 

 

Spill Prevention and Control Plans (SPCP) should clearly state measures to stop the source of a 

spill, contain the spill, clean up the spill, dispose of contaminated materials, and train personnel to 

prevent and control future spills. SPCPs are applicable to construction sites where hazardous wastes 

are stored or used. Hazardous wastes include pesticides, paints, cleaners, petroleum products, 

fertilizers, and solvents. Make equipment and materials for cleanup readily accessible, and mark 

them clearly so workers can follow procedures quickly and effectively. A SPCP can be highly 

effective at reducing the risk of surface and ground water contamination. 

 

Vehicle Maintenance and Washing occurs in garages and wash facilities, not usually at 

construction sites. If these activities must occur onsite, operators should follow appropriate BMPs 

to prevent untreated wastewater or hazardous wastes from being discharged to surface or ground 

waters. Vehicle maintenance and washing BMPs prevent construction site spills of wash water, 

fuel, or coolant from contaminating surface or ground water. Using a covered, paved area for 

washing, ensuring that areas are properly connected to a storm drain system, and properly handling 

and disposing of vehicle wastes and wash water should all be taken into consideration when 

implementing this BMP. These techniques effectively reduce discharges of untreated automotive 

wastes and wash water to receiving waters. 

 4.4 PHYSICAL RESOURCES 

4.4.1 EARTH RESOURCES

Constructing a building or facility involves a variety of activities, including the use of equipment 

that alters the site’s environmental conditions. Construction activities typically involve excavating 

and clearing existing vegetation, top soil removal, re-grading, and drainage pattern alterations. 

Pollutants associated with C&D industry stormwater discharges can adversely affect the 

environment in a number of ways. Potential effects include impairment of water quality, destruction 

of aquatic life habitats, and enlargement of floodplains. Soil and groundwater disturbance can 
Construction and Development NPDES General Permit Environmental Assessment 

53 

mobilize pollutants already present on a C&D site due to a broad range of human activities and land 

uses that can contaminate a site’s soil and groundwater. 

 Industrial activities can directly deposit a wide range of pollutants in soil and groundwater, 

including metals, nutrients, and toxic organic compounds (Folkes et al. 2001; Seattle and 

King County Public Health 2001; Area Wide Soil Contamination Task Force 2003; Blanco 

et al. 2009). 

 Agricultural lands can contain elevated levels of pesticide residues, nutrients from fertilizers 

and manure (particularly phosphorus), and salts from irrigation waters (New Jersey DEP 

1999; Area Wide Soil Contamination Task Force 2003; Renshaw et al. 2006; Robinson et al. 

2007; Stone and Anderson 2009) and constitute a large (approximately 40%) portion of 

currently developed land (NRC 2008). 

 In urban areas, construction often begins with demolition and removal of existing buildings 

and other structures. Materials in preserved wood (e.g., creosote, chromated copperarsenate); paint chips and dust (including lead-based paints); brick and wood scraps; 

concrete debris; asbestos-based insulation and other materials; polychlorinated biphenyls 

(PCBs) from old electricity transformers; metal scrap; waste solvents; historic fuel spills; 

and fill material composed of coal ash and clinkers, brick and concrete demolition debris, 

and other industrial by-products may be present (Blanco et al. 2009). Pesticides have been 

widely used in urban areas, as well, and residues may persist in soil and other materials 

(Folkes et al. 2001). Erosion and leachate from these materials may elevate pH, metals, and 

toxic organic compounds levels in stormwater runoff. 

 Atmospheric deposition is a source for several contaminants, including metals (e.g., copper, 

chromium, lead, mercury, and zinc), nutrients (nitrogen, phosphorus), and organic 

compounds (e.g., PAHs, PCBs, and pesticides). These contaminants are generated by both 

stationary and mobile sources, e.g., smelters, power plants, motor vehicles, and wind-borne 

dusts (Folkes et al. 2001; NRC 2008). Although atmospheric deposition from such sources 

is more likely to occur downwind near urbanized areas, atmospheric deposition can be very 

widespread and affect undeveloped areas (e.g., undisturbed forest). Atmospheric deposits of 

persistent pollutants may accumulate to significant levels (Seattle and King County Public 

Health 2001, Area Wide Soil Contamination Task Force 2003), e.g., from leaded fuels that 

have elevated lead levels in many urban soils. 

In addition to adverse physical effects of sedimentation, sediments are associated with a variety of 

other types of pollutants. Stormwater runoff from cleared and exposed areas may also contain 

hazardous contaminants or pollutants, whether naturally occurring or from previous land use, can 

increase pollutant transport to surrounding waterbodies. For example, nitrogen and phosphorus are 

common, sediment-associated soil constituents that can also pollute receiving waters as excess 

nutrients. 

Other pollutants come from construction equipment and materials or from historic contamination at 

construction sites. These pollutants include metals, trash and debris, nutrients, organic matter, 

pesticides, petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and other toxic 

organics, and pathogens (USEPA 2009a). Construction activity can also affect receiving waters by 

increasing the volume and intensity of stormwater runoff from a site. These flows can erode 

receiving water banks and beds, particularly when pipes, ditches, or other stormwater conveyances 

concentrate discharges. Surface water erosion can alter waterbody morphology and elevate 

sediment and turbidity levels downstream (USEPA, 2009b).
Construction and Development NPDES General Permit Environmental Assessment 

54 

Different land uses produce differing levels of sediment loads to watersheds. Forested watersheds in 

the US are estimated to yield 0.02 tons to 1 ton sediment/acre/year. Cropland in the US is estimated 

to yield 15- to 30-fold higher sedimentation rates, ranging from 0.65 tons to 15 tons 

sediment/acre/year (Vice et al. 1969; Yorke and Herb 1978; Osterkamp et al. 1998; Faucette et al. 

2007). C&D activity generally increases sedimentation 100- to 10,00-fold greater than forested 

areas, with reported sediment yields of 0.009 tons to 219 tons sediment/acre/year from catchments 

containing construction (Paul and Meyer 2001). All studies of construction site sediment yield 

report that construction activity increases sediment discharges from sites. 

Because of the importance of precipitation and its subsequent flow over land to the transport of soil, 

most sediment and turbidity discharges take place during or shortly after precipitation events. Once 

a precipitation event ceases, discharges from construction sites generally cease within a relatively 

short time period unless site terrain or stormwater management systems, such as stormwater ponds, 

attenuate discharge flows. This dynamic creates an intermittent discharge of pollutants from most 

construction sites. 

During the construction period, the affected land is usually stripped and the soil compacted, leading 

to the potential for increased stormwater runoff and high rates of erosion. If the exposed areas 

contain either naturally occurring hazardous contaminants or pollutants from previous land uses, 

pollutants can be carried at increased rates to surrounding waterbodies by stormwater runoff. 

Although the cleared construction site is only a temporary condition (usually lasting less than 6 

months), the landscape is permanently altered even after the land has been restored by replanting 

vegetation due to the intrinsic nature of development. 

Vegetation plays such an important part in erosion control that re-vegetation is an important, n 

effective stormwater/erosion mitigation technique. Vegetative stabilization measures employ 

plantings to protect soil exposed to the erosive forces of water and wind. Selected vegetation can 

reduce erosion by more than 90 percent (Fifield 1999b). Natural plant communities that are adapted 

to the site provide a self-maintaining cover that is less expensive than structural alternatives. Plants 

provide erosion protection to vulnerable surfaces (Heyer no date) by: 

• Protecting soil surface from the impact of raindrops 

• Holding soil particles in place 

• Maintaining the soil’s capacity to absorb water 

• Using living root systems to hold soil in place, increasing overall bank stability 

• Directing flow velocity away from the streambank 

• Acting as a buffer against abrasive transported materials 

• Causing sediment deposition that reduces sediment load and reestablishes the stream bank. 

4.4.2 WATER RESOURCES

C&D activities can generate a broad range of environmental impacts by introducing new sources of 

contamination and by altering the physical characteristics of the affected land area. These activities 

can result in both short- and long-term adverse effects on surface water quality in streams, rivers, 

and lakes in the affected watershed by increasing the loads of various pollutants in receiving 

waterbodies, including sediments, metals, organic compounds, pathogens, and nutrients. Ground 

water also can be adversely affected through diminished recharge capacity. Other potential effects 

include the physical alteration of existing streams and rivers due to the excessive flow and velocity 

of stormwater runoff (USEPA 2009a). 
Construction and Development NPDES General Permit Environmental Assessment 

55 

Precipitation events are the primary cause of construction site sediment and turbidity discharges to 

surface waters. Raindrop impact energy and overland water flow detach soil particles from the land 

surface, suspend them in surface flow, and transport them to other locations on the construction site 

or to discharge points. Suspended soil particles in the stormwater flow create turbidity. 

 Construction sites discharge sediment and turbidity to all major surface water categories —lakes, 

reservoirs, ponds, and other impoundments; streams and rivers; wetlands and estuaries; and bays 

and other coastal waters. Some waterbodies have flow regimes and physical structures that allow 

them to purge or absorb excess sediment and turbidity inputs within relatively short time frames. 

Other surface water regimes allow excess sediment and turbidity to persist for long periods of time. 

The ability of individual surface waters to transport sediment varies as precipitation and other 

factors modify the nature of their flow. Surface waters also vary widely in their size relative to 

construction site discharges. Larger surface waters generally have more capacity for dilution of 

soluble pollutant discharges and dispersion of particulate and particulate-associated pollutants. 

Sediment and turbidity movement within surface waters is highly variable. Factors influencing 

sediment and turbidity movement and persistence in surface waters include the intensity, quantity, 

and composition of sediment and turbidity discharges and the nature of the receiving waters. 

Important waterbody characteristics include type, size, and flow rate. 

Sediments and turbidity migrate with surface water flow downstream and, therefore, can affect 

waters beyond the initial receiving water. Migration of construction sediment typically benefits the 

initial receiving water but impacts downstream waters. Several studies have documented 

improvements in stream conditions once construction site sediment and turbidity discharges cease 

and accumulated sediments migrate downstream from the initial point of entry. The sediments, 

however, remain within the surface water network and are redistributed to new waterbodies 

downstream. Because of sediment’s ability to persist and migrate downstream, surface waters 

downstream of a watershed containing a consistent level of construction activity from year to year 

can experience a relatively consistent level of impact from construction sediment and turbidity 

discharges, even though the timing of individual precipitation events and the locations of individual 

construction sites within the watershed change from year to year. 

The degree to which soil particles remain suspended helps to determine the degree to which it will 

be able to move with water flow within a surface water or whether it will be deposited on a surface 

water bed. It also determines whether or not a sediment particle will contribute to surface water 

turbidity, since only suspended particles increase turbidity levels. Particles smaller than 0.063 mm 

(silt and clay) tend to remain suspended in flowing freshwater systems and are the primary 

contributors to water turbidity (USEPA 2009b). 

4.4.2.1 Freshwater Ecosystems 

The transport and fate of mobilized sediment depends on the flow characteristics of the receiving 

water and the settling characteristics of the sediment, and the most fundamental physical 

characteristic of sediments is their settling velocity. Lake, pond, and reservoir flow environments 

more closely approximate the still-water conditions under which Stokes’ law (USEPA 2009b) 

applies to sediment particles to predict settling velocity. The assumption of Stokes-type settling is 

often used to predict the rate of sedimentation by comparing the time required for a particle to settle 

with the particle’s transit time through the waterbody. Several surface water characteristics 

influence settling and transit times, including size, shape, depth, and regulation of outflow (USEPA 

2009b) and these characteristics vary widely among lakes, ponds, and reservoirs. 
Construction and Development NPDES General Permit Environmental Assessment 

56 

Streams and rivers have a strong, primarily unidirectional flow as a distinguishing characteristic. 

Stream and river sediment transport is predominantly controlled by stream transport capacity, and 

the sediment physiochemical characteristics and supply rate. Larger sediments generally experience 

more episodic movement over longer time scales through watersheds. Smaller sediments generally 

move more continuously and within a shorter time scale. 

Sediments transported by rivers and streams are typically described as bed load and suspended load. 

The boundary separating these categories changes with flow conditions. Sediments not in transport 

at a given time are often referred to as bedded sediments. If flow conditions change, these 

sediments can become bed load or suspended load. Sediment particle size is the primary 

distinguishing factor among these categories, with the largest particles deposited as bedded 

sediments, larger particles moving as bed load, and finer particles moving as suspended load. Total 

sediment load consists of the sum of bed load and suspended load (USEPA 2009b) 

The variation in soil types found in the United States is a significant factor in estimating sediment 

discharges. EPA used soil coverage data provided in the State Soil Geographic Database 

(STATSGO) (Wolock 1997; USDA 2007) and the CONUS-SOIL data layers (Miller and White 

1998) for the loadings analysis. STATSGO component and layer tables were accessed through the 

Pennsylvania State University’s active archive 

(http://www.soilinfo.psu.edu/index.cgi?soil_data&index.html). EPA extracted data for only the 

portions of RF1 watersheds where development change has been documented by NLCD. EPA used 

an urbanization change mask to create RF1 watershed parameter values. The geographic limits of 

the soil coverage evaluated were determined by superimposing indicator city urban area 

boundaries—from the U.S. Census Bureau’s 2000 Urbanized Areas Cartographic Boundary Files 

(U.S. Census Bureau 2000)—on intersecting RF1 watersheds. 

 The resulting list of RF1 watersheds intersecting the rapidly developing indicator city urban areas 

was used to spatially identify underlying STATSGO soil coverage Map Unit Identifiers (MUIDs). 

Soil data associated with the surface soil layer within the selected MUIDs were extracted from 

STATSGO to produce the suite of data evaluated for each indicator city. EPA also used GIS data to 

determine the percentage of each hydrologic soil group (HSG) for each RF1 watershed using the 

urban masking approach. The percentages for RF1 HSGs were then used to estimate runoff 

coefficients for each RF1 watershed (USEPA 2009a). 

EPA (waters (http://www.epa.gov/waters/ir/index.htm) also performed a set of analyses using the 

Assessment TMDL Tracking and Implementation System (ATTAINS) to assess the relative 

contribution of sediment and turbidity as causes of impairment in impaired rivers and streams, lakes 

and reservoirs, and bay and estuaries. Of the approximately 935,120 total river and stream reach 

miles analyzed, 458,209 miles (49%) have been identified as impaired. Sediment contributes to 

impairment in 107,231 miles (23%) of impaired river and stream waters; turbidity/suspended solids 

contribute to impairment in 26,278 miles (5.7%) of impaired river and stream waters. For lakes and 

reservoirs, of the approximate total 17,492,935 acres analyzed, 11,545,337 acres (66%) are 

identified as impaired. Sediment contributes to impairment in 715,558 lake acres (6.2%); 

turbidity/suspended solids contribute to impairment in 1,008,276 acres (8.7%). For bays and 

estuaries, of the approximate total 11,400,127 acres analyzed 7,182,080 acres (63%) are identified 

as impaired. Sediment contributes to impairment in 133,760 acres (1.9%) of impaired bay and 

estuary waters; turbidity/suspended solids contribute to impairment in 153,699 acres (2.1%) of 

impaired bay and estuary waters. 
Construction and Development NPDES General Permit Environmental Assessment 

57 

EPA assessed changes in water quality for the C&D Rule using the U.S. Geological Survey’s 

SPARROW modeling (Spatially Referenced Regressions on Watershed attributes). For the analysis 

described in EPA 2009b, SPARROW was used to evaluate the effectiveness of a range of 

regulatory options for controlling construction related runoff and improving water quality as 

measured by in-stream Total Suspended Solids (TSS), TN and TP concentrations. SPARROW 

models for the conterminous United States for sediment, nitrogen, and phosphorus were used to 

characterize baseline water quality conditions. 

EPA performed extensive SPARROW modeling for total suspended sediment (TSS) and the 

nutrients total nitrogen (TN) and total phosphorus (TP) for the conterminous US, described in 

Schwarz (2008a). EPA’s approach relied on empirical relationships between baseline in-stream 

TSS/TN and TSS/TP concentrations to derive estimates of the post-compliance nutrient reductions.

The TSS analysis was based on mass flux estimates compiled from more than 1,800 long-term 

monitoring stations operated by the USGS during the period 1975-2007. SPARROW modeling is 

structured on the RF1 stream network, consisting of approximately 62,000 reach segments and 

more than 4,000 reservoirs. The model identifies six sources of sediment, including the stream 

channel and five classes of land use (urban, forested, federal non-forested, agricultural and other). 

Table 4-2 presents the results, which show, per unit area, Federal non-forested and urban lands are 

the largest landform sediment sources. 

Table 4-2. Estimation Results for the SPARROW Suspended Sediment Model 

Parameter Units Estimate Standard Error 

Federal Non-forested land 

Urban land 

Agricultural land 

Other land 

Forested Land 

Streambed (reach length) 

kg/km2/yr 

kg/km2

/yr 

kg/km2/yr 

kg/km2

/yr 

kg/km2

/yr 

kg/m/yr 

64,344 

47,130 

18,047 

11,343 

634 

28.80 

12,411 

9,925 

3,623 

3,186 

898 

6.40 

Source: Schwarz as reported in EPA 2009b 

Reducing soil erosion and sediment runoff from construction sites not only reduces sediment 

loadings into streams, but can also reduce concentration of other pollutants that are present in the 

soil. To evaluate the water quality benefits of these ancillary reductions, EPA developed an 

approach that relies on the empirical relationship observed between baseline in-stream suspended 

sediment concentrations and Total Nitrogen (TN) and Total Phosphorous (TP) concentrations to 

derive estimates of the post-compliance nutrient reductions. 

USGS developed SPARROW models for TN and TP transport for the non-tidal conterminous 

United States as described in Smith et al. (1997). Observed TN and TP transport rates were derived 

from water-quality records for 414 stations in the National Stream Quality Accounting Network. 

Nutrient sources identified in the regression equations include point sources, applied fertilizer, 

livestock waste, nonagricultural land, and (for TN only) atmospheric deposition. Surface 

characteristics found to be significant predictors of land-water delivery include soil permeability, 

stream density, and (for TN only) air temperature. 

The nutrient/TSS ratio was calculated using SPARROW model outputs of TSS, TN, and TP mass 

flux related to land-based runoff for the baseline conditions; ratios were calculated for each 
Construction and Development NPDES General Permit Environmental Assessment 

58 

individual reach. EPA averaged the reach-level ratios to the HUC8 watershed level to obtain a 

nutrient-to-sediment ratio that represents the average relationship between in-stream nutrients and 

suspended sediments within each basin. EPA later uses these watershed-average ratios to estimate 

reach-specific changes in suspended sediment concentrations for each scenario to yield estimated 

reach-level changes in nutrient concentration. 

EPA also estimated impacts on waterbody TSS levels using SPARROW. Table 4-3 summarizes 

sediment loadings for current CGP and proposed CGP scenarios based on the national baseline 

annual estimated sediment loading of 2,580,000 tons, the estimated current CGP estimated 

sediment loadings (based on the current CGP’s 4.6% share of national C&D activity), and the 

projected sediment loadings of the proposed CGP that incorporates the C&D Rule. The proposed 

CGP is expected to result in a reduction of 40,020 tons, a 34% reduction compared to the current 

estimated CGP sediment loadings of 118,680. 

Table 4-3. Baseline C&D Stormwater Loading Summary and Post-Compliance Reductions 

Analysis Sediment Loading, tons Sediment Reduction, tons Percentage Reduction 

from Current CGP 

Current CGP 118,680 

Proposed CGP 78,660 40,020 34% 

Source: total US baseline sediment loadings (2,580,000 tons) and total US reach miles post-compliance BAT/NSPS,

sediment loadings (600,000 tons), EPA 2009b

Table 4-4 summarizes national average reach-length weighted TSS concentrations in RF1 reaches 

as estimated by SPARROW under the C&D Rule and the pre- and post- proposed CGP scenarios. 

Information is presented for all reaches in the RF1 network that receive sediment loading from 

construction sites. Table 4-4 also presents information on the distribution of TSS concentrations for 

the median (50th percentile) TSS concentration for the current CGP (289.3 mg/L) and proposed 

CGP (288.6 mg/L, for a decrease of 0.7 mg/L). 

Table 4-4. Distribution of TSS Concentration based on SPARROW Output for RF1 Reaches 

Receiving C&D Stormwater Discharges 

Scope of Analysis Reach 

Count 

Reach 

Miles 

Modeled 

Average 

TSS 

(mg/L)1 

Reduction in 

Average TSS 

(mg/L)1

Median TSS 

Concentration

(mg/L)1

Reduction in 

Median TSS 

(mg/L)1 

Current CGP 1,469 18,955 956.4 - 289.3 - 

Proposed CGP 1,469 18,955 955.0 1.5 288.6 0.7 

1. Reach length-weighted 

Source: total US baseline reach count (31,927) and reach miles modeled (412,062 mi), EPA 2009b 

Table 4-5 describes the number of RF1 reach miles improved and the distribution of TSS 

concentration reductions for the proposed CGP relative to the current CGP TSS. Table 4-5
Construction and Development NPDES General Permit Environmental Assessment 

59 

summarizes projected sediment reduction in terms of reach miles improved at various levels of TSS 

reduction for the current CGP and proposed CGP. Proposed CGP issuance improvements in TSS 

concentrations of > 50 mg/L are projected for 16 reach miles; improvements of 10-50 mg/L are 

projected for 84 reach miles; improvements of 5 - 10 mg/L are projected for 138 reach miles; 

improvements of 1 -5 mg/L are projected for 1,087 reach miles; improvements of 0 -1 mg/L are 

projected for 16,632 reach miles; reach miles with improved TSS concentrations total 17,957 miles. 

In evaluating these improvements, however, SPARROW modeling of the reduction in loadings and 

concentrations in reaches that receive construction sediment discharge directly does not account for 

the decreased loadings and concentrations in downstream reaches. The total number of reach miles 

and degree of improvement that are analyzed and presented in Table 4-5, therefore, are 

underestimates. Table 4-6 summarizes average, reach-length weighted TN and TP concentrations 

for the current CGP, and the proposed CGP for reaches receiving C&D sediment discharges. TN 

and TP concentrations in the RF1 network vary over a wide range. The average TN concentration is 

18.22 mg/L under the current CGP while for the proposed CGP the TN level decreases 0.01 mg/L 

to 18.21 mg/L. The average TP concentration is 3,921.6 mg/L under the current CGP while for the 

proposed CGP the TN level decreases 5.3 mg/L to 3,916.3 mg/L. 

Table 4-6. Distribution of TN and TP Concentrations Based on SPARROW Output 

for RF1 Reaches Receiving Direct C&D Stormwater Discharges 

Scope of Analysis Reach 

Count 

Reach 

Miles 

Average 

TN 

(mg/L)1 

Reduction in 

Average TN 

(mg/L)1

Average 

TP 

(mg/L)1 

Reduction in 

Average TP 

(mg/L)1 

Current CGP 1,469 18,955 18.22 - 3,921.6 - 

Proposed CGP 1,469 18,955 18.212 0.022 3,916.32 5.32

1. Reach-length weighted 

2. Rounding of significant numbers may result in inconsistent values within the text and tables. 

Source: total US baseline reach count (31,927) and reach miles (412,062 mi), EPA 2009b 

Table 4-5. Total RF1 Miles that Receive Direct C&D Loadings with Improvements in TSS 

Concentrations 

Scope of 

Analysis 

Total RF1 

Miles 

Total Miles 

with Reduced 

TSS1

Reach Miles Improved 

 Ranges of Reductions in TSS Concentration (mg/L) 

0 - 1 1 – 5 5 - 10 10 - 50 ≥ 50 

Current CGP 18,955 17,957 - - - - - 

Proposed CGP 18,955 17,957 16,632 1,087 138 84 16 

1. Not included in the total are 40 reaches (422 reach miles) where SPARROW did not predict concentrations. 

The 99.9% fraction represents all reach miles over which SPARROW calculates TSS concentrations. 

Source: total US baseline reach miles (412,062) and total US post-compliance BAT/NSPS reach miles with 

reduced TSS (390,374), EPA 2009b 
Construction and Development NPDES General Permit Environmental Assessment 

60 

Note that these numbers represent national, CGP-wide concentration reductions, and do not reflect 

the wide geospatial variability in TN and TP concentration reductions. Also, changes in nutrient 

concentrations are based on in-stream sediment reductions. Therefore, the distribution and 

magnitude of percent change in reach miles will be the same as for TSS (USEPA 2009b). 

4.4.2.2  Water Quality Index

To link water quality changes from reduced sediment discharge to effects on human uses and 

support for aquatic and terrestrial species habitat for the C&D Rule, EPA utilized a water quality 

index (WQI). The index translates water quality measurements, gathered for multiple parameters 

that are indicative of various aspects of water quality, into a single numerical indicator. The 

parameters used in formulating the WQI were determined based on waterbody type, scientific 

understanding of ecosystem response to varying conditions, and available data. The WQI provides 

the link between pollutant levels and both the presence of aquatic species and the suitability for 

particular recreational uses. The WQI value is measured on a scale from 0 to 100 and reflects water 

quality ranging from 0 for poor quality to 100 for excellent quality. 

To support the analysis of changes in sediment loadings from construction sites relative to baseline 

conditions, EPA adapted Cude’s (Cude 2001) methodology to a national scale by developing subindex curves for TSS at the level of ecoregions. EPA also further modified the WQI methodology 

to apply to estuarine reaches, building on prior applications of WQI concepts to saltwater 

environments (Harrison et al. 2000; Canadian Council of Ministers of the Environment 2001; 

Carruthers and Wazniak 2003; Gupta et al. 2003; and USEPA 2007a). 

EPA implemented the WQI methodology by using three key steps: (1) obtaining water quality 

measurements for each parameter included in the WQI; (2) transforming measurements to subindex values expressed on a common scale; and (3) weighting and aggregating the individual 

parameter sub-indices to obtain an overall WQI value that reflects waterbody conditions across the 

parameters. These steps are described in full in EPA 2009b. The freshwater WQI used by EPA to 

evaluate water quality in rivers and streams included six parameters selected to represent major 

stream impairment categories: dissolved oxygen (DO), biochemical oxygen demand (BOD), fecal 

coliform (FC), total nitrogen (TN), total phosphorus (TP), and total suspended solids (TSS). 

The estuarine WQI included parameters that are common to both freshwater and saltwater 

systems— dissolved oxygen, nitrogen, phosphorus, fecal coliform, and suspended solids—and 

replaced biochemical oxygen demand with chlorophyll-a (ChA). ChA is a measure of amount of 

phytoplankton present in the waterbody. While phytoplankton are a natural component of a 

waterbody’s food web, changes in its abundance (e.g., high ChA), species composition, and 

productivity are commonly the first biological response to nutrient enrichment (Chesapeake Bay 

Program 2008, as cited in EPA 2009b). Subsequent decomposition of the phytoplankton may 

reduce available dissolved oxygen and induce hypoxia and anoxia. 

Baseline freshwater WQI values are based on baseline data for 60,017 reaches in the coterminous 

United States. Baseline concentrations for all WQI parameters were available for a total of 9,444 

reaches. EPA used a successive average approach to address the data gaps in the remaining 

freshwater reaches. For estuaries and coastal reaches, EPA used a similar approach to estimate 

missing concentration values based on the average concentrations available for reaches within 

consecutively coarser HUC levels. Due to the smaller scale of estuarine waterbodies, EPA used the 
Construction and Development NPDES General Permit Environmental Assessment 

61 

average of concentration values for HUC8, HUC6, and HUC 4 to estimate average parameter 

concentrations for reaches where data gaps existed and did not estimate values based on HUC2 

averages. 

Each RF1 reach that had an improved WQI value relative to its baseline WQI value contributed to 

estimated economic benefits. Based on the estimated WQI value under the baseline scenario, EPA 

categorized each RF1 reach using four WQI ranges (WQI < 25, 25≤WQI<50, 50≤WQI<70, and 

70≤WQI). WQI values of less than 25 indicate that water is not suitable for boating (the recreational 

use with the lowest required WQI), whereas WQI values greater than 70 indicate that waters are 

swimmable (the recreational use with the highest required WQI). For each WQI category under the 

baseline scenario, EPA estimated the weighted average WQI using reach miles as weights. 

The difference in WQI between baseline conditions and CGP-related conditions (ΔWQI) is a 

measure of the change in water quality. To monetize benefits of the regulation, EPA used three 

ranges of water quality improvements 0.01< ΔWQI ≤ 0.1, 0.1 < ΔWQI ≤ 0.5, and 0.5 < ΔWQI). For 

each baseline water quality category and improvement range combination, EPA estimated the 

average ΔWQI and the corresponding percentage of total reach miles. 

In this analysis, the numbers of reach miles improved, .i.e., that experience a change in the WQI 

value, differ from the numbers presented in Section 4.4.2.1, which used absolute changes in TSS, 

TN, or TP concentrations. An additional difference is that the data presented cover all reaches 

within the RF1 network, including those that do not receive construction discharge directly but may 

nevertheless see improvement due to changes in water quality in upstream reaches. Changes in 

water quality under the current CGP and the proposed CGP are presented in Table 4-7. 

4.4.2.3  Human Use

Ultimately, changes in sediment and other pollutant loadings from construction sites related to the 

final regulation affect humans through influences on the production of goods and services that enter 

into individuals’ utility functions. Table 4-8 summarizes some of the important ways in which 

sediment and other pollutant discharges from construction sites affect the quantity and quality of 

services provided by the natural environment and how these services in turn provide economic 

value to society through various use and nonuse related societal welfare mechanisms. Underlying 

this table is a conceptual framework based on the valuation of ecosystem services (Daily 1997; 

Simpson and Christensen 1997; van Houtven et al. 2005, as cited in EPA 2009b). EPA was not 

able to bring the same depth of analysis to all of the environmental services affected by the 

regulation categories, however, because of imperfect understanding of the link between discharge 

Table 4-7. Estimated Pre-Proposed CGP and Post-Proposed CGP Water Quality Improvements

Scope of 

Analysis 

Baseline 

Scenario, 

Total Reach 

Miles Modeled 

0.01< ΔWQI ≤ 0.1 0.1 < ΔWQI ≤ 0.5 0.5 < ΔWQI Total Improved 

Reaches 

Reach Miles Reach Miles Reach Miles Reach Miles 

Current CGP 28,873 - - - - 

Proposed 

CGP 28,873 2,773 449 139 3,361 

Source: total US baseline total reach miles modeled (650,043) and total reach miles modeled (627,679), EPA, 

2009b
Construction and Development NPDES General Permit Environmental Assessment 

62 

reductions and benefit categories, and how society values some of the benefit events. EPA was able 

to quantify and monetize some benefits (including maintenance to navigable waterways, reservoir 

dredging, drinking water treatment, and WTP for improvements in large river and streams and some 

coastal waters), quantify but not monetize other benefits (changes in pollutant concentrations in 

lakes), and assess still other benefits only qualitatively (e.g., commercial fishing, flood damages, 

and property values) (EPA 2009b). 

Table 4-8. Summary of Benefits from Reducing Sediment and Other Pollutants in Stormwater Discharges 

from C&D Sites 

Activity 

Environmental Service 

Flows Potentially Affected 

by Discharges from 

Construction Sites 

Entities Affected by Environmental Changes 

Methods Used in 

EPA’s Analysis of 

Benefits from the 

Regulation Firms Governments Individuals 

Recreation: 

Outings, boating, 

swimming, fishing 

Aesthetics, water clarity, 

water safety, degree of 

sedimentation, 

eutrophication, weed 

growth, fish and shellfish 

populations 

Y Use & Nonuse 

Values Benefits Transfer 

Commercial fishing 

and shellfishing 

Fish and shellfish 

populations Y Y Use & Nonuse Values Qualitative Discussion 

Property ownership 

Aesthetics, safety of 

property from flooding, 

property value 

Y Y Use & Nonuse 

Values Benefits Transfer 

Water conveyance and 

supply; 

Water storage; 

Water treatment 

Turbidity, degree of 

sedimentation Y Y Use Values 

Avoided cost to 

governments, 

including: 

Reservoir dredging, 

Drinking water 

treatment 

Water Transportation 

Degree of sedimentation of 

navigational channels, 

harbors, and other 

waterways 

Y Y Use Values Avoided cost to firms 

and governments 

Water use: 

industrial, 

municipal, 

agricultural 

Turbidity Y Y Use Values Qualitative Discussion 

Knowledge 

(no direct uses) Environmental health Nonuse Benefits Transfer 

Source: EPA 2009b

Transportation

Implementation of the regulation is expected to result in less frequent dredging of navigable 

waterways due to reduced sediment runoff from construction sites. This will result in avoided costs 

to the government and private entities responsible for maintenance of navigational shipping 
Construction and Development NPDES General Permit Environmental Assessment 

63 

channels, harbors, rivers, and other waterways (EPA 2009b). For the period 1995–2008, including 

dredging performed by USACE and dredging contracted to other firms, USACE funded nearly 

3,400 dredging occurrences, worth more than $9 billion (2008$). This dredging removed more than 

2.6 billion cubic yards of sediment from more than 1,100 navigable reaches (EPA 2009b). 

Location information provided by USACE Dredging Information System was given by latitude–

longitude coordinates for some jobs, but for others, location information was limited to the name of 

the job (usually the waterway dredged) and the USACE district that performed the job. To identify 

the nearest reach segment, EPA used ERF 1.2 (Enhanced Reach File) from USGS. For this analysis, 

EPA researched latitude/longitude coordinates for jobs where they were not provided and linked 

them to Reach File Version 1.0 (RF1) reaches. Each latitude/longitude of interest was matched to 

the nearest point in the ERF 1.2 universe of points using a spherical model of the earth and a 

standard haversine distance formula. To associate the point with an RF1 reach number, EPA used 

the “RR” (River Reach) attribute from the ERF 1.2 attribute table. No reach types were excluded 

from consideration in the nearest reach calculation. Because these coordinates may be inexact, 

dredging activity was aggregated to the state level for the calculations in this analysis and is 

presented at a regional level (EPA 2009b). 

EPA assumed that navigable waterways that are regularly dredged would benefit from reducing the 

amount of sediment that needs to be dredged up. Although other waterways may benefit from 

reduced sedimentation, EPA based its estimation of reduced dredging activity based on historic 

dredging data from USACE. For dredging jobs that occurred only once between 1995 and 2008, 

EPA assumed that this job or one similar to it will occur over the same time frame in the future. 

However, these single occurrence jobs are excluded from the low range estimate of the analysis 

(EPA 2009b). 

The total quantity of sediment dredged for each job (single location) over the past 14 years was 

divided by the number of occurrences of that job to calculate an average quantity of sediment 

dredged for an occurrence of that job. EPA assumed that this quantity of sediment would be 

dredged each time the job occurs in the future under the baseline scenario, and that it would be 

reduced due to the regulation (EPA 2009b). 

EPA estimated changes in sediment deposition in navigable waterways under different regulatory 

scenarios using output from SPARROW. For the post-compliance scenarios, EPA calculated the 

percentage change in sediment yield from the baseline for each RF1 reach in the SPARROW 

analysis. The quantity of sediment for each dredging job was multiplied by this percentage change 

in sediment yield to obtain a post-compliance quantity of sediment to be dredged each time a job 

occurs in the next 14 years (EPA estimated future dredging for 14 years to reflect the 14 years of 

historic data provided by USACE). If an RF1 reach was not assigned to a dredging job due to data 

limitations or the reach assigned to that dredging job was not included in the SPARROW model 

(such as coastal reaches), the state-wide average reduction in sediment yield was applied to that job 

(EPA 2009b). 

To account for uncertainty in projecting future dredging costs, EPA adjusted the assumptions to 

provide a range of benefits estimates. EPA estimated low, midpoint, and high levels of dredging 

activity for this sensitivity analysis as follows: 

 Low estimate: 
Construction and Development NPDES General Permit Environmental Assessment 

64 

▫ Assuming a minimum recurrence interval (below which occurrences are assumed to be 

continuations of the previous occurrence of the same job) of 180 days 

▫ Assigning 10th percentile cost and cubic yards dredged estimates for jobs lacking these 

data 

▫ Excluding jobs with only one occurrence over the 14 years from 1995 to 2008. 

 Midpoint estimate: 

▫ Assuming a minimum recurrence interval of 90 days to include jobs with more closely 

spaced recurrences 

▫ Using 50th percentile (median) cost and cubic yards dredged estimates for jobs lacking 

these data 

▫ Including jobs with only one occurrence over the 14 years from 1995 to 2008 under the 

assumption that these jobs or similar jobs will occur once over the next 14 years. 

 High estimate: 

▫ Assuming a minimum recurrence interval of 30 days 

▫ Using 90th percentile cost and cubic yards dredged estimates for jobs lacking these data 

▫ Including jobs with only one occurrence between 1995 and 2008 under the assumption 

that these jobs or similar jobs will occur once over the next 14 years. 

EPA annualized its 14-year dredge projection in order to facilitate the comparison of these costs to 

other costs calculated for the analysis of the regulation that are measured on an annual time frame 

(costs associated with sediment removal are reported in Section 4.5). Table 4-9 presents estimated 

total annualized dredging (cubic yards removed) for navigable waterway dredging for the current 

and proposed CGPs. The table provides projected low, midpoint, and high estimates. Table 4-9 also 

presents annualized low, midpoint, and high estimates of navigable waterways dredging avoided 

under the proposed CGP. The avoided dredging activity considered the benefit to navigation 

resulting from the proposed CGP. 

Table 4-9. Annualized Navigable Waterway Dredging, Pre- and Post-CGP Issuance 

Scope of Analysis Total Sediment Dredged (million cubic yards) 

Low Midpoint High 

Current CGP 96.3 120.3 127.9 

Proposed CGP 95.9 119.9 127.5 

 Reduction in Sediment Dredged (million cubic yards) 

Proposed CGP 0.4 0.4 0.4 

Source: total US baseline low (2,093), midpoint (2,616), and high (2,781) estimated navigable waterways dredging, 

EPA 2009b

Reservoirs

EPA also examined impacts of C&D stormwater discharges on reservoir locations, uses, and 

historic sedimentation rates. Information is available from the Reservoir Sedimentation Survey 

Information System (RESIS) database (USGS 2007b). Formally known as RESISII, this database 

was initially developed by the USDA Natural Resources Conservation Service, and was provided to 

EPA by USGS. The database includes 4,227 sedimentation survey results from 1,818 reservoirs 
Construction and Development NPDES General Permit Environmental Assessment 

65 

located across the conterminous US. Results from 1775 to 1992 are represented, with the majority 

of measurements covering the mid-20th century and later. RESIS does not include all US 

reservoirs, nor does it contain information about dredging activity in reservoirs or about any other 

methods for recapturing lost water storage capacity. RESIS documents the total sediment deposition 

per reservoir is more than 1,360,252 tons annually (EPA 2009b). 

C&D stormwater discharges affect not only sediment concentrations in receiving water bodies, but 

also affect the amount of sedimentation occurring in reservoirs. EPA estimated annual sediment 

attenuation rates in each reservoir using output data from SPARROW modeling for all reservoirs on 

reaches modeled by SPARROW. The amount of sediment settling in reservoirs is the basis for 

estimating the quantity of sediment dredged from reservoirs and the cost of this dredging (EPA 

2009b). The difference between estimated dredging under the current CGP and projected dredging 

under the proposed CGP provides the benefit attributed to the proposed CGP from the reduction in 

dredging activity. Table 4-10 presents current CGP and proposed CGP dredging and projected 

reductions in dredging. For more than 4,000 reservoirs distributed throughout the RF1 network, 

SPARROW modeling estimated more than 444 million cubic yards accumulate annually under 

C&D Rule baseline conditions (EPA 2009b). Relative to the pre-CGP issuance reservoir 

sedimentation baseline of 20.4 million cubic yards, post-CGP issuance reservoir sedimentation is 

reduced 25,723 cubic yards. 

Table 4-10. Estimated Sediment Removed by Reservoir Dredging Under the Baseline 

Scenario and CGP-related Reductions 

Scope of Analysis Baseline Sediment 

Dredged (yd3

) 

Current CGP 20,451,885 

Proposed CGP 20,426,162 

Estimated Reduction (yd3) 25,723 

Drinking Water

Drinking water treatment plants provide the essential services of removing contaminants from water 

taken from surface and ground sources, making the water potable. Sediment is one of the 

contaminants that must be removed from drinking water before it can be consumed, so a reduction 

in sediment levels in water taken up by drinking water treatment plants is expected to result in 

lower treatment costs for these plants (cf. Boardman et al. 2001). 

The primary concern of sediment in terms of drinking water treatment is the turbidity that results 

from suspended sediment in the water column. As turbidity increases in drinking water influent, the 

variable costs of water treatment to mitigate this turbidity increase. 

EPA modeled sediment concentrations in RF1 stream reaches under both the current and final 

scenarios using the SPARROW model. Drinking water treatment facilities located on waterbodies 

with typically higher levels of TSS and turbidity may have systems in place that reduce total 

suspended solids and turbidity levels in influent water before it is chemically treated. EPA assumed, 

as per Ngo and Nichols (1998), that facilities with baseline TSS concentrations exceeding 1,000 

mg/L would employ a process such as plain sedimentation, during which influent water is allowed 

to settle for extended periods of days or weeks. The effectiveness of this process depends on the 

size of the sedimentation basin and the amount of time the water is left to settle. Studies by Yao 
Construction and Development NPDES General Permit Environmental Assessment 

66 

(1973) and DeZuane (1997) suggest that the effectiveness of plain sedimentation ranges from 30 

and 90% with a midpoint estimate of 60%. Thus, EPA varied the effectiveness of plain 

sedimentation basins between 90, 60, and 30% TSS removal for the low, mid, and high benefit 

estimates, respectively. The more effective the plain sedimentation process, the lower the treatment 

costs to the affected facilities, and consequently, the lower their potential savings from reduced 

influent turbidity (USEPA 2009b). 

This reduction is applied to influent water TSS concentrations at facilities that are estimated to have 

influent water with TSS concentrations exceeding 1,000 mg/L in the baseline. Table 4-11 presents 

the low, midpoint, and high estimates of treated turbidity under the baseline scenario and the 

current CGP, and under the proposed CGP, as well as the projected reduction of treated turbidity 

under the proposed CCP. 

Table 4-11. Drinking Water Turbidity Under the Baseline Scenario and Reduction of Drinking 

Water Turbidity Under Option 1 and Option 4 

Scope of Analysis Average Treated Turbidity (NTU) 

Low Midpoint High 

Current CGP 104.0 205.9 486.0 

Proposed CGP 103.8 205.5 485.1 

Reduction in Treated Turbidity (NTU 0.2 0.4 0.9 

Source: : total US estimated baseline and post-compliance BAT/NSPS low (2,093), midpoint (2,616), and high 

(2,781) average treated turbidity, EPA 2009b

Recreation

EPA did not quantify direct impacts of this rule to recreational uses. However, removal of sediment 

deposited within navigable waterways or decreasing turbidity in reservoirs and drinking water 

inherently increases the recreational use of streams, rivers, reservoirs, lakes, bottomlands, and 

estuaries. Table 4-11 through 4-13 provide the reduction in sedimentation and turbidity and that 

would directly impact the recreational use of waterways within the United States. 

Sediment and other discharges from construction sites can directly impact reproduction and survival 

of aquatic species. Impacts to aquatic species can have a profound effect on subsistence anglers, 

commercial anglers, and consumers, as well as recreational anglers. 

4.4.3 CUMULATIVE IMPACTS

The above discussion of impacts of the proposed re-issuance of the CGP on physical resources 

intrinsically addresses cumulative impacts for several reasons. As the Federal action of issuing a 

new source NPDES permit, a general permit explicitly addresses cumulative impacts by evaluating 

impacts, costs, and benefits at the Agency’s best estimate of projected industry activity that will 

occur under the proposed general permit. Thus, the discussions presented above fully anticipate and 

specifically include analyses at the sum total projected level of C&D activity that EPA expects 

under the proposed CGP. 

In developing the proposed CGP, EPA has addressed the entire span of C&D industry activity, i.e., 

from the level of individual sites to aggregated industry activity at the national level. Also, by 

addressing sediment and nutrient loadings for streams, rivers, lakes and estuaries from individual 

waterbodies to a national level, EPA also has addressed the entire span of environments most 
Construction and Development NPDES General Permit Environmental Assessment 

67 

affected by stormwater discharges form C&D sites. EPA modeled 31,927 RF1 reach segments, and 

more than 1,819 reservoirs to determine reduction of sediment, TSS, and nutrient loadings from 

construction activity. EPA also used background data from 729 estuaries and modeled for TSS 

loadings for 43 estuaries to calculate Water Quality Index values for estuaries. 

Furthermore, EPA has addressed individual site-specific concerns by incorporating specific features 

into the permitting process. Also, when a NOI is received, designated EPA regional contacts are 

notified of the application so they can review the individual C&D site activity if needed. By 

incorporating such protections into the NOI process, EPA has ensured “no significant cumulative 

effect” will occur because the process for obtaining coverage has been developed with specific, 

appropriate, conditions and requirements that anticipate the consequences of multiple C&D sites as 

each individual application is received and reviewed. 

4.5 BIOLOGICAL RESOURCES 

EPA provided a qualitative approach to effects of construction site stormwater runoff on biological 

resources and reviewed the literature to identify potential effects to biological resources. Any 

removal of “non-natural” sedimentation and turbidity will benefit the aquatic environment. A 

variety of organisms, including aquatic plants, invertebrates, amphibians, and fish, are affected by 

elevated sediment and turbidity levels. High levels of sediment and turbidity reduce photosynthetic 

activity and food availability, bury habitat, directly harm organisms, and alter the composition of 

the aquatic community. 

Naturally occurring levels of sediment or turbidity vary from waterbody to waterbody. Some 

aquatic ecosystems are adapted to higher levels of sediment or turbidity (e.g., some large coastal 

floodplain rivers), whereas other ecosystems are adapted to lower levels of sediment or turbidity 

(e.g., alpine lakes, headwater streams). Short-term increases in suspended sediment and turbidity 

levels can naturally occur during spring thaws, storms, and other high flow events. Both the 

magnitude and duration of sediment and turbidity exposure are important. 

Because organisms vary in their ability to tolerate and recover from exposure proportion of 

sensitive species declines in waterbodies affected by increased sedimentation and turbidity. 

However, even organisms adapted to relatively high sediment or turbidity can be harmed by 

significantly higher levels of sediment and turbidity than that to which they have adapted or if their 

resiliency is taxed by other stressors. 

Many construction sites have been documented to discharge other pollutants in addition to sediment 

and turbidity such as nitrogen, phosphorus, metals, and other organic and inorganic compounds. A 

number of these other pollutants travel with sediment as it erodes and moves through the surface 

water network. In addition, many construction sites discharge to surface waters already impacted by 

stressors including pollutant discharges from other sources, invasive species, and flow modification. 

Interactions among sediment, turbidity, and other stressors and their cumulative effects on aquatic 

organisms have not been fully characterized (USEPA 2009b). 

Sediments and turbidity can also affect chemical, fungal, and microbial decomposition processes in 

aquatic ecosystems. Depending on the source and nature of the sediments, sedimentation can 

change the organic content of surface water sediment, which can alter fungal and microbial 

community activity. Rapid sediment deposition over an organic sediment layer can also cause a 

shift to anaerobic conditions in the isolated strata and an accompanying shift in microbial 

metabolism, methane generation, and nutrient dynamics (USEPA 2009b). In wetlands, depressed 
Construction and Development NPDES General Permit Environmental Assessment 

68 

levels of algal and microbial biomass and density can indicate chronically elevated sedimentation 

levels (USEPA 2009b). 

4.5.1 AQUATIC VEGETATION AND WILDLIFE RESOURCES

4.5.1.1  Primary Producers

Primary producers transform sunlight into energy and provide food for other aquatic organisms. 

Primary producers, including algae, phytoplankton, submerged aquatic vegetation, and other 

macrophytes (plants with large leaves), are found in most aquatic ecosystems. Primary producers 

can grow in a variety of forms: rooted to surface water substrate, free-floating, or attached to rocks, 

aquatic plants, or other structures. The term periphyton refers to the algae, small plants, bacteria, 

microbes, and detritus attached to submerged surfaces in aquatic ecosystems. 

Aquatic ecosystems vary in the degree to which they derive energy and resources from primary 

producers. For example, some systems are heavily dependent on the productivity of primary 

producers (e.g., sea grass beds) while others (e.g., small streams in forested watersheds) derive a 

large proportion of their energy from external sources, such as leaf debris) (USEPA 2009b). 

Several studies have indicated that increased turbidity results in decrease of primary production 

through light reduction, physical damage and substrate modification (Kerr et al. 1995). Aquatic 

macrophytes and algae influence water column chemistry, including dissolved oxygen, pH, and 

nutrient levels; provide important habitat for many organisms; and reduce waterbody flow velocity. 

Loss of algae and macrophytes due to elevated sediment and turbidity levels can compound the 

effects of these pollutants as fewer plant structures are available to slow the water flow that 

facilitates settling of suspended sediment from the water column. This compounding effect can 

result in elevated suspended sediment and turbidity levels persisting further downstream (USEPA 

2009b). 

4.5.1.2  Aquatic Invertebrates

Aquatic invertebrates, including zooplankton, insects, crustaceans, and bivalves (e.g., mussels and 

clams), are widely distributed among aquatic ecosystems and can be found in even the smallest 

surface waters. They provide an important link in the aquatic food chain between primary producers 

and larger organisms such as amphibians, reptiles, fish, birds, and mammals (USEPA 2009b). 

Because many benthic macroinvertebrates are relatively stationary and have limited powers to 

evade polluted waters, their abundance, diversity, and species composition is widely used as an 

indicator for overall aquatic ecosystem health (USEPA 2009b). 

Increased sedimentation can directly and indirectly cause invertebrate mortality. The effects of 

elevated sediment and turbidity levels on invertebrates, particularly on benthic macroinvertebrates, 

have been the focus of a large number of studies over the past several decades. Aquatic 

invertebrates can be affected by loss of habitat and inability to feed as well as causing direct 

mortality. In both freshwater and marine ecosystems most macroinvertebrates are limited by their 

mobility and any increased sedimentation can impact their habitat by smothering, changes within 

substrate composition and their ability to forge for food (Waters 1995; Berry et al. 2003). Changes 

within the substrate composition can also affect the food source for macroinvertebrates, while 

increased turbidity can impede filter feeders ability to remove food from the water column (Kerr 

1995; Waters 1995). 

The severity of sediment and turbidity impacts on invertebrate populations is related to the intensity 

and duration of exposure (USEPA 2009b). If disturbance to a macroinvertebrate community is 
Construction and Development NPDES General Permit Environmental Assessment 

69 

intense enough, it may impact the ability of the community to recover its former condition, 

particularly if sensitive organisms are eliminated from surrounding areas, as well, or habitat has 

been modified to the point where it is no longer able to support the former community (USEPA 

2009b). Healthy invertebrate populations in unaffected parts of a surface water system can provide 

organisms to re-colonize disturbed areas once construction activity has ceased (USEPA 2009b). 

4.5.1.3  Fishes

Both freshwater and marine/estuarine fishes can be affected by suspended sediments, turbidity and 

increased sedimentation. Possible impacts are loss of habitat, loss of a food source and loss of 

spawning habitat. Many fishes use the river, steam and estuarine bottoms for cover, spawning mats, 

and food foraging areas. Increased turbidity reduces both foraging and avoidance capabilities while 

increased suspended sediments can cause physical damage and mortality. Increased sedimentation 

or suspended sediments can create a complete shift in population dynamics (Berry et al. 2003; 

Barton 1977; Reid et al. 2003; Kerr 1995; Hedrick et al. 2006). 

Like invertebrates, fish use crevices in waterbody beds for feeding, shelter from predators and high 

flow events, and reproduction. Loss of these interstitial spaces degrades fish habitat (USEPA 

2006b). Sediment can also decrease the depth of or eliminate other important habitats such as 

stream pools and wetlands adjacent to surface waters. Riparian wetlands are particularly important 

for fish spawning. Fish are also affected by loss or decline in aquatic macrophytes, which are 

important sources of shelter and food for a number of fish species. Coral reef bleaching and decline 

severely impact fish habitat in coral reef ecosystems. 

The level of impact on fishes from suspended sediments and turbidity is a function of the 

interaction of many factors, including natural sediment and turbidity levels for the area in question. 

Short-term increases in suspended sediment and turbidity levels naturally occur and aquatic 

ecosystems also vary in their natural sediment and turbidity levels. Studies have found that, in 

general, fish typically found in environments with naturally high turbidity preferred more turbid 

environments in the laboratory (USEPA 2009b). Other fish species are very sensitive to elevated 

sediment levels (e.g., entire salmonid fisheries have been destroyed by elevated sediment levels) 

(USEPA 2009b). 

The level of impact on fishes from suspended sediments and turbidity also depends on other factors, 

including pollutant concentration; exposure duration; particle size; ambient temperature; physical 

and chemical properties of the sediments; associated toxins; co-occurring stressors; and fish 

acclimatization, life history stage, migration, and breeding season (USEPA 2009b). In general, 

longer duration and higher level exposures produce greater effects. Milder, primarily behavioral 

effects are observed at lower magnitude and duration exposure levels. As exposure and duration 

levels increase, effects become sublethal and lethal (USEPA 2009b). Several efforts to construct 

models linking varying levels and durations of sediment exposure to fish responses, but responses 

vary widely among different species, and data are generally insufficient at this time to fully 

characterize many of them (USEPA 2009b). 

A construction project may produce sediment and turbidity levels significantly higher those 

associated with natural events, for longer periods of time, and at times when an aquatic ecosystem 

is unaccustomed to receiving such sediment inputs. Many fish species have seasonal migration and 

breeding behaviors which can be disrupted by elevated sediment levels. Younger fish are more 

vulnerable to sediment impacts and are more prevalent within a population at certain times of the 

year (USEPA 2009b). 
Construction and Development NPDES General Permit Environmental Assessment 

70 

4.5.2 TERRESTRIAL VEGETATION AND WILDLIFE RESOURCES

There are few studies available on the effects of elevated sediment and turbidity levels in aquatic 

ecosystems on fundamentally terrestrial wildlife that utilize aquatic ecosystems. Most available 

studies examine effects on birds. Loons appear to need clear water for hunting fish and may avoid 

turbid waters for nesting. Other studies documented birds modifying their fish hunting behaviors 

and distribution on a surface water in order to avoid more turbid areas, probably because of 

increased foraging difficulty (USEPA 2009b). 

Birds, mammals, reptiles, and amphibians that consume aquatic plants, invertebrates, fish, and other 

aquatic organisms or otherwise utilize aquatic habitats for shelter and reproduction can also be 

affected by elevated sediment and turbidity levels in surface waters. Some species are sufficiently 

mobile that they can avoid impacted aquatic communities and seek substitutes, if available and 

accessible (USEPA 2009b). 

Sedimentation can also affect or eliminate riparian wetlands, important habitats for the laying of 

amphibian egg masses (USEPA 2009b). 

4.5.3 THREATENED & ENDANGERED SPECIES

The Endangered Species Act (ESA) of 1973 (16 U.S.C. 1531 1543) establishes a national policy to 

protect and conserve threatened and endangered species and the ecosystems upon which they 

depend. The ESA prohibits Federal agencies from jeopardizing threatened or endangered species or 

adversely modifying habitats essential to their survival. The ESA is administered by the USFWS 

and the NMFS. Section 7 of the ESA governs interagency cooperation and consultation. EPA has 

coordinated with the USFWS and the NMFS, both collectively known as the “Services.” 

Coverage under the proposed CGP is available only if stormwater discharges, allowable nonstormwater discharges, and stormwater discharge-related activities are not likely to jeopardize the 

continued existence of any species that are federally-listed as endangered or threatened (“listed”) 

under the ESA or result in the adverse modification or destruction of habitat that is federallydesignated as critical under the ESA (“critical habitat”). Operators have an independent ESA 

obligation to avoid prohibited “take” of listed species under ESA Section 9. Many of the 

requirements and procedures in the CGP to protect listed species will assist operators in avoiding 

prohibited take. Additionally, a C&D site is eligible to discharge under the CGP only if stormwater 

discharges, allowable non-stormwater discharges, or stormwater discharge-related activities would 

not cause a prohibited “take” of federally-listed endangered or threatened species (as defined under 

section 3 of the ESA and 50 CFR 17.3), unless such takes are exempted/authorized under sections 7 

or 10 of the ESA. 

The proposed CGP contains the both permit provisions and also establishes a process through 

operator selection of eligibility criteria in an appendix of the permit which is focused exclusively on 

protection of threatened and endangered species and their critical habitat. A C&D site is only 

eligible for coverage under the CGP if it properly complies with the terms and conditions of the 

permit; including implementing Best Management Practices (BMPs) discussed in Section 4.3 to 

meet the non-numeric and water quality-based effluent limitations. This includes implementing a 

myriad of restrictions on erosion and sediment controls, pollution prevention, and site stabilization; 

all which reduce impacts of the stormwater discharge from construction activities on T&E species. 
Construction and Development NPDES General Permit Environmental Assessment 

71 

Operators must certify to one of the endangered species eligibility criteria listed in the appendices 

of the permit. If an operator cannot certify to one of the endangered species eligibility criteria, they 

cannot submit an NOI to gain coverage under the CGP; instead they must apply to EPA for an 

individual NPDES permit. As appropriate, EPA will conduct ESA Section 7(a)(2) consultations 

when issuing individual permits. If there are concerns that CGP coverage for a particular facility 

may result in adverse effects to listed species or critical habitat, EPA may hold up discharge 

authorization until such concerns are adequately addressed. Documentation of both the BMP’s and 

supporting information for the selection of the appropriate eligibility criteria must be kept with the 

SWPPP and the terms and conditions of the permit are legally enforceable. 

Additionally, the permit provides the Services with the opportunity to review all NOIs and their 

associated certifications. Once an operator submits its NOI, its authorization to discharge is stayed 

during a “waiting period”. Contacts at EPA, USFWS, and NMFS within a region or state, receive 

an email automatically generated by EPA’s eNOI system that an NOI requesting coverage for a 

C&D site activity within their area of jurisdiction has been submitted and certified. This 

notification initiates the review period for the agencies to confirm, reject, or put a hold on the CGP 

coverage pending further review. The waiting period provides for an opportunity for review by the 

Services and EPA to ensure that the operator’s certification of eligibility is appropriate. If the 

Services have concerns or questions regarding an individual discharger’s certification of eligibility, 

they may request that EPA delay permit coverage for the identified facility. When permit coverage 

is delayed, the Services and EPA will work with the affected operator to resolve any concerns. If 

concerns cannot be resolved, the Services can recommend that EPA deny coverage under the CGP. 

Based on the above provisions, the eligibility criteria built into the proposed permit and their 

reduction of impacts to water quality from stormwater discharges from construction activities on T 

& E species, EPA concludes that the proposed action will not have a significant adverse effect on 

threatened and endangered species or critical habitat present in the coverage area of the proposed 

CGP. 

4.5.4 TERRESTRIAL IMPACTS FROM BMP REQUIREMENTS OF THE PROPOSED GCP 

The implementation of the requirements of the C&D Rule in the proposed GCP require permittees 

to follow Best Management Practices that are described extensively in the C&D Rule. The primary 

focus of these BMPs is the protection of the quality of the stormwater discharge. Consequently, 

there may be environmental trade-offs from some of the BMPs EPA recommends that may affect 

resources at C&D sites other than aquatic resources. 

EPA has considered the impacts of these recommended BMPs to resources other than aquatic 

resources. Table 4-12 presents recommended BMPs and the types of potential adverse impacts that 

may result from their implementation. EPA expects adverse impacts from BMPs to be highly 

localized, limited in scope, and highly transient. 

Table 4-12. EPA Menu of Stormwater BMPs for Construction Activities and the Potential for 

 BMP-Generated Environmental Impacts 

Construction Site Stormwater BMP Potential for Adverse Environmental Impacts 
Construction and Development NPDES General Permit Environmental Assessment 

72 

Construction Site Planning and Management

 Construction Sequencing No BMP-generated impact 

 Construction Site BMP Inspection & Maintenance No BMP-generated impact 

 Land Grading No BMP-generated impact 

 Preserving Natural Vegetation No BMP-generated impact 

Erosion Control 

 Biodegradability; soil microbiology 

 Increased nutrients/metals runoff; 

 Dust Control Nominal impacts, depending on extent 

 Geotextiles Nominal impacts 

 Gradient Terraces Excavation; grading of new areas 

 Invasive/noxious plant species 

 Riprap Nominal impacts, depending on extent 

 Seeding Invasive/noxious plant species 

 Sodding Invasive/noxious plant species 

 Soil Retention Excavation; grading of new areas 

 Soil Roughening Excavation; grading of new areas 

 Temporary Slope Drain Berm area impacts 

 Excavation 

 Wind Fences and Sand Fences Nominal; restricted wildlife mobility if extensive 

Runoff Control

 Check Dams Nominal impacts 

 Excavation 

 Excavation 

 Excavation 

Sediment Control

 Shallow trenching 

 Compost Filter Berms Increased nutrients/metals runoff; Invasive/noxious plants if 

 Compost Filter Socks Increased nutrients/metals runoff; Invasive/noxious plants if 

 Construction Entrances Nominal impacts 

 Fiber Rolls Shallow trenching 

 Filter Berms Nominal impacts 

 Sediment Basins and Rock Dams Excavation 

 Sediment Filters and Sediment Chambers Excavation 

 Sediment Traps Excavation 

 Silt Fences Nominal; restricted wildlife mobility if extensive 

 Storm Drain Inlet Protection Nominal impacts 

 Straw or Hay Bales Nominal impacts 

 Vegetated Buffers Nominal impacts 

Good Housekeeping/Materials Management

 Concrete Washout No BMP-generated impact 

 General Construction Site Waste Management No BMP-generated impact 

 No BMP-generated impact 

 No BMP-generated impact 

4.5.5 CUMULATIVE IMPACTS

EPA has not quantified impacts from stormwater discharges from C&D sites for two reasons. One 

is that the state of the science is such that although there sufficient date to support qualitative 
Construction and Development NPDES General Permit Environmental Assessment 

73 

statements of impact, the ability to make sufficiently reliable projections of potential quantitative 

impacts across the span of environments that may be affected is not sufficiently reliable. The 

numerous factors and their inter-relationships that must be considered to describe cause and effect 

relationships are not adequately advanced to make projections with sufficient confidence to 

quantify and monetize costs and benefits to these biological resources. 

The second reason is that the proposed CGP will cover a very wide range of aquatic resources, and 

the available information and analytic tools are not sufficiently reliable to attempt a bottom-up 

analysis that aggregates impacts of all the potentially affected ecosystems. Rather, for the proposed 

CGP, similar to the C&D Rule, EPA is addressing potential impacts by assessing costs and benefits 

on a national level and projecting these to the subset of C&D sites covered under the limited scope 

of the proposed CGP. EPA has confidence in its quantification and monetization of the impacts, 

costs, and benefits to physical resources: 

• Modeling conducted by EPA projects an annual reduction of sediment loadings from 

118,680 tons to 78,660 tons, a 34% reduction (40,020 tons) annually (see Table 4-3); 

• The proposed CGP is projected to reduce average TSS concentrations by 1.5 mg/L; average 

TP concentrations by 5.3 mg/L, and average TN concentrations by 0.02 mg/L (see Tables 4-

4 and 4-6); 

• The proposed CGP is projected to improve the water quality index in nearly 15% of reach 

miles potentially affected under the proposed CGP Table 4-7). 

Section 4.4 provided the estimated reductions in loadings of TSS, Turbidity, TN, and TP that are 

projected under the proposed CGP. All of these potential pollutants have been studied in the 

literature and have been proven to have impacts on aquatic organisms. The removal of these 

pollutants will reduce unwanted sedimentation in spawning areas, prevents smothering aquatic 

plants and sessile invertebrates, and allow for natural light penetration and natural predator/prey 

relationships. Thus, although EPA has only quantified the impacts to physical resources, the 

available information on qualitative impacts to biological resources supports the conclusion that 

the improvements resulting from the proposed CGP to physical resources will result in 

improvements to biological resources as well, even if not quantifiable at this time. 

Also as discussed in Section 4.4.5 above, in developing the proposed CGP, EPA has addressed the 

entire span of C&D industry activity and the entire span of environments most affected by 

stormwater discharges from C&D sites by addressing impacts to streams, rivers, lakes and estuaries. 

As the Federal action of issuing a new source NPDES permit, a general permit explicitly addresses 

cumulative impacts by evaluating impacts, costs, and benefits at the Agency’s best estimate of 

projected industry activity that will occur under the proposed general permit. In developing the 

CGP EPA has addressed individual site-specific concerns by incorporating specific features into the 

permitting process that include a review of CGP applications that will ensure “no significant 

cumulative effect” will occur because of specific, appropriate, conditions and requirements that 

anticipate the consequences of multiple C&D sites as each individual application is received and 

reviewed. 

4.6 SOCIOECONOMIC RESOURCES 

EPA has reviewed the impacts of C&D site stormwater discharges on socioeconomic resource costs 

and benefits. EPA has considered both direct industry compliance costs and indirect market effects 

from the proposed CGP due to decreased sedimentation and turbidity associated with the issuance 
Construction and Development NPDES General Permit Environmental Assessment 

74 

of the proposed CGP. EPA considered the following specific market effects that could occur in 

response to the proposed CGP: 

1. Regulatory requirements may increase construction costs and lengthen project construction 

periods, which further increases total project costs. Increased project costs may in turn 

adversely affect the financial performance of construction projects and the firms that 

undertake these projects and/or increase the prices paid by consumers of C&D industry 

output. Increased prices will increase sale prices or rents of completed projects. The extent to 

which increased construction costs manifest as higher sales prices and rents will depend on 

supply and demand elasticities in specific construction product markets. These elasticities 

may vary substantially both over time, across regional markets, and within regional markets 

according to supply and demand conditions in specific product segments. 

2. Consumers’ response to increased project prices can affect the overall bundle of 

characteristics (e.g., size, technical design and finished product specifications) that determine 

consumers’ value of, and price paid for, the finished real estate product. Faced with increased 

construction costs and potential price increases for a finished product, consumers (and project 

developers as their surrogate) may select lower cost specifications on other aspects of final 

project design. The flexibility to adjust project design specifications can buffer consumers 

from the construction cost increase and upward price pressure resulting from regulatory 

requirements, but may also result in trade-offs of valuable attributes. Such flexibility is 

particularly important if the potential construction cost and price increases are substantial and 

consumers faced income-based constraints on the price (or rent) that may be paid for the 

finished product. 

3. If producers are unable to pass all increased costs along to consumers in the form of higher 

prices, this could lead to weakened financial performance of, and lower employment among, 

C&D industry businesses. Affected businesses may lose business value and could face 

financial stress, leading potentially to reductions in business activity and, in the worst case, 

closure of individual businesses. Given the relative fluidity of the C&D industry sectors 

expected to be affected by this regulation, idled economic resources – i.e., labor and capital – 

might be redeployed relatively quickly into other existing C&D industry businesses or new 

industry entrants. Regional and temporal variation in market response to increased 

construction costs and potential price effects may lead to substantial variation in the extent 

and character of impacts within the C&D industry. 

All of these regulatory response effects – increased construction costs from regulation compliance; 

distribution of compliance costs among owners of undeveloped property, construction businesses, 

and consumers; changes in the characteristics of C&D industry finished product; and potential 

effects on the timing and configuration of property development – reflect the internalization of 

construction-related costs to society that are currently not accounted for in the private transactions 

of property purchase, development, and sale/rent. These cost and price effects, and the decision 

responses by property owners, producers and consumers, are indicative of the correction of 

production costs and market prices to account for the costs to society that were previously 

unaccounted for in the various affected transactions. 

4.6.1 LAND USE

Increased sedimentation in streams, rivers, and lakes from construction activities can affect various 

land uses. Irrigation water that contains sediment or other pollutants from construction sites can 
Construction and Development NPDES General Permit Environmental Assessment 

75 

harm crops and reduce agricultural productivity. Suspended sediment can result in formation of a 

crust over a field and reduce water absorption, inhibit soil aeration, and prevent emergence of 

seedlings. Sediment transported via spray irrigation water can also coat the leaves of plants, 

inhibiting plant growth and reducing crop value and marketability. Also, irrigation water 

containing dissolved salts or pollutants can harm crops and damage soil quality (Clark et al. 1985). 

Pumps are often used for the movement of irrigation water, and excess sediment levels may require 

the use of filters to improve water quality (USEPA 2009b). Erosion and deposition of sediment in 

surface waters has led to failure of pumping equipment Wolman and Schick (1967). 

Surface water sedimentation also can block irrigation water intake structures or require periodic 

dredging or relocation. Sedimentation can cause sediment build-up in irrigation water canals and 

other transport systems (Osterkamp et al. 1998), reducing their efficiency. Sediment build up can 

also accumulate in livestock water supply impoundments and reduce their capacity (USEPA 

2009b). 

4.6.2 WATER RESOURCES USES

4.6.2.1  Water Quality Index

In assessing the potential benefits of reduced construction-generated sedimentation due to the 

promulgation of the C&D Rule, EPA considered non-market benefits such as improved aquatic life, 

wildlife, and habitat designated uses. These benefits will be implemented through their 

incorporation into the requirements of the proposed CGP. As described in Section 4.4.2.2 above, 

EPA utilized a water quality index (WQI) to provide a link between specific pollutant levels (such 

as dissolved oxygen) and the presence of aquatic species and the suitability for particular 

recreational uses. EPA estimated state-level household mean, lower 10th percentile bound, and 

upper 90th percentile bound willingness-to-pay for expected changes in WQI and aggregated 

benefits to the national level. 

EPA estimated that the total annual benefits (in 2008$) of water quality improvement resulting from 

reduced sediment discharges from C&D sites range from a low estimate of $55 million to a high 

estimate of $430 million, with a mean estimate of $210 million. 

4.6.2.2  Human Uses

Transportation

The primary effect of pollutant discharges from construction sites on navigation and transportation 

is the accumulation of sediment in navigational channels and harbors (USEPA 2004b). Keeping 

these areas passable requires extensive dredging, which can be costly. Issuance of the proposed 

CGP is expected to result in less frequent dredging of navigable waterways due to reduced sediment 

discharges from construction sites. As a result, cost savings will accrue to government and private 

entities responsible for maintenance of navigational shipping channels, harbors, and other 

waterways. EPA used the avoided cost of navigational waterways dredging as a measure of benefits 

resulting from the issuance of the CGP. 

EPA’s analysis of benefits to navigation included four primary steps: 

 Identify navigable waterways that are regularly dredged and estimate the frequency of 

dredging in each waterway; 

 Estimate the navigable waterway maintenance cost per cubic yard of sediment dredged; 
Construction and Development NPDES General Permit Environmental Assessment 

76 

 Estimate the total cost of navigable waterway maintenance under the baseline and postcompliance scenarios and, 

 Estimate avoided costs from decreased dredging of navigable waterways due to the 

reduction in sediment discharged from construction sites. 

EPA made assumptions regarding low, midpoint, and high estimates for the baseline dredging that 

will be affected by the permit in order to provide a range of benefits values. The avoided costs, 

based on the baseline and BAT/NSPS national projections, are calculated as the difference in total 

annualized dredging costs between the current CGP and the proposed CGP, and are considered as 

the benefits to navigation resulting from the proposed CGP. Table 4-13 presents annualized 

avoided cost estimates for navigable waterway dredging. Only the midpoint estimate for cost 

reductions and a 3% annual discount rate to discount and annualize costs is presented as this a 

reasonably conservative amount under each of these scenarios. 

Annualized savings from reduced dredging activity under the proposed CGP represents a savings of 

$132,250 at the midpoint estimate. The total reduction in sediment dredged from navigable waters 

is expected to be nearly a million cubic yards. Table 4-13 presents the avoided costs estimated 

under the proposed CGP from implementing the requirements of the C&D Rule. 

Table 4-13. Annualized Reductions in Navigable Waterways Dredging 

Sediment Dredged, million cubic yd3

 Low Midpoint High 

Current CGP 96.3 120.3 127.9 

Proposed CGP 95.9 119.9 127.5 

Reduction 0.40 0.40 0..40 

Costs, 2008$ 

Low Midpoint High 

Current CGP $ 21,827,000 $ 28,538,400 $ 30,116,200 

Proposed CGP $ 21,779,772 $ 28,480,569 $ 30,054,933 

Reduction $ 47,228 $ 57,831 $ 61,267 

Source: total US baseline low (2,093), midpoint (2,616), and high (2,781) estimated sediment dredged and 

post-compliance BAT/NSPS low ($474.5 million), midpoint $620.4 million), and high ($654.7million) 

estimated costs, EPA 2009b 

Reservoirs

Reservoirs are water impoundments, often manmade, that serve many functions, including 

providing drinking water, flood control, hydropower supply, and recreational opportunities. The 

C&D Rule analyzed and quantified the benefits of the reduced sedimentation from implementing 

the rule. As in the analysis above for reduction in dredging for navigable waterways, the reduced 

sedimentation from the implementing the requirements of the C&D Rule in the proposed CGP 

reduced the frequency of dredging needed to maintain reservoirs. Likewise, EPA estimated the 

savings in the form of avoided costs associated with reduced reservoir dredging.. 
Construction and Development NPDES General Permit Environmental Assessment 

77 

EPA assumed that all sediment entering reservoirs must be removed in order to maintain the current 

water storage capacity in the United States. The frequency of dredging is highly site-specific, 

depending on many factors including the average sediment concentration of the river or stream, the 

size of the reservoir and excess storage capacity, and any sediment routing practices. EPA chose a 

general frequency of 6 years for a midpoint estimate of a low of 2 years and a low 10 year. For this 

analysis, EPA assumed that the average unit cost of dredging sediment from a navigable waterway 

is approximately equal to the average unit cost of dredging sediment from a reservoir Table 4-14

presents annualized avoided cost estimates reservoir dredging implementing the C&D Rule in the 

proposed CGP. 

Table 4-14. Annualized Reductions in Reservoir Dredging 

Sediment Dredged, 

million cubic yd3

Estimated Costs, 2008$

Low Midpoint High 

Current CGP 444,606,867 $ 1,051,600,000 $ 1,596,800,000 $ 1,696,000,000 

Proposed CGP 443,283,323 $ 1,048,596,400 $ 1,593,606,100 $ 1,692,609,600 

Reduction 1,322,867 $ 3,003,600 $ 3,193,900 $ 3,390,400 

Source: total US baseline (444,606,867) and post BAT/NSPS compliance estimated sediment dredged 

(443,283,323) and baseline low ($1,051.6 million), midpoint ($1,596.8 million), and high ($1,696.0 million) EPA 

2009b

Drinking Water

As mentioned above in Section 4.4.2.3, the primary concern of sediment that would accumulate 

from unabated increase in construction site runoff in terms of drinking water treatment is the 

turbidity that results from suspended sediment in the water column. As turbidity increases in 

drinking water influent, the variable costs of water treatment to mitigate this turbidity increase. The 

variable costs associated with treating drinking water for turbidity are twofold: (1) Adding chemical 

coagulants that bond to the sediment particles and foster precipitation from the water column and 

(2) disposing of the sludge resulting from this treatment (Table 4-15). EPA’s analysis in estimating 

the avoided costs for decreased sedimentation from the C&D rule consisted of modeling sediment 

concentrations and reductions, identifying reaches with drinking water intakes and their intake 

volumes, then estimating of chemical turbidity treatment cost and sludge disposal costs. 

Recreation

EPA did not quantify and monetize certain potential benefits from the proposed CGP. This 

qualification was primarily directed at benefits to biological resources. However, several nonquantified benefits are identified that relate to sediment and turbidity impacts on the recreational 

uses of surface waters. 

Aesthetically, polluted water greatly reduces the aesthetic appeal of a variety of recreational 

activities that take place in or near surface waters, including boating, swimming, hunting, and 

outings to hike, jog, picnic, camp, and view wildlife. Turbidity caused by sediment discharges may 

affect the safety of boating. 

Turbidity contributes to increased water hazards. It creates safety hazards for swimmers and divers 

by reducing the ability to see underwater hazards; for divers by impairing the ability to gauge water 

depth; and for any distressed contact water user who become submerged by making their location 

more difficult (USEPA 2009b). For boaters, turbidity may obscure underwater obstacles, which 
Construction and Development NPDES General Permit Environmental Assessment 

78 

increases the likelihood of collisions; increased sedimentation levels may create sandbars, which 

increase the chances of running aground. Clark et al. (1985) estimated that turbidity (from all 

sources) may be responsible for as many as 200 boating fatalities and many more injuries each year. 

The C&D Rule analysis estimated that the value for a statistical life was approximately $7 million. 

At 200 boating fatalities from turbidity from all sources, based on the C&D activity estimated to be 

covered under the proposed CGP, the face value of preventing these fatalities is approximately $64 

million per year. As noted, however, this figure derives from turbidity from all sources, and that due 

to C&D activity is only a portion of this. Still, given that this figure does not include any accounting 

for turbidity-related boating injuries, the potential monetary value of preventing boating accidents 

by reducing sedimentation and turbidity from C&D activities may be quite substantial (USEPA 

2009b). 

Table 4-15. Annualized Reductions in Drinking Water Treatment Costs 

Average Reduction of Treated Turbidity, (NTU) 

Low Midpoint High 

Current CGP 104.0 205.9 486.0 

Proposed CGP 103.8 205.5 485.1 

Reduction 0.2 0.4 0.9 

Costs, 2008$

 Low Midpoint High 

Current CGP $ 15,764,200 $ 23,961,400 $ 29,959,800 

Proposed CGP $ 15,719,194 $ 23,906,209 $ 29,901,569 

Reduction $ 45,006 $ 55,191 $ 58,231 

Source: total US baseline low (104 NTU), midpoint (205.9 NTU), and high (486.0 NTU) and estimated treated 

turbidity and baseline low ($3,42.7 million), midpoint (520.9 million), and high ($651.3 million), EPA 2009b

Recreational fishing may also be negatively affected by sedimentation and turbidity. Stormwater 

discharges from construction sites can reduce fish populations by inhibiting reproduction and 

survival by stressing predator/prey relationships. This may lead to fewer and smaller game fish. In 

addition, turbidity caused by sediment and other pollutant discharges may lower catch rates of game 

fish for recreational anglers by reducing the distance over which fish can see lures. Although EPA 

has not quantified the potential decrease in fish populations due to construction site stormwater 

discharges, EPA anticipates that issuing the proposed CGP will decrease sedimentation and 

turbidity in surface waters and result in non-quantified benefits for a variety of surface water 

recreational activities. 

There are also indirect benefits that accrue to improving recreational uses. For example, a 2006 

study of Maryland’s marine recreation businesses shows recreational water users can significantly 

contribute to economic growth in the coastal communities in which they are based. A study 

undertaken under a Sea Grant Extension Program documented the value of recreational boating 

activity in Maryland at well over a billion dollars a year — excluding the sale price of boats 
Construction and Development NPDES General Permit Environmental Assessment 

79 

(http://www.mdsg.umd.edu/programs/extension/communities/boating/index.php). According to the 

report, approximately every 6.5 boats registered in Maryland lead to more than one full-time job 

somewhere in the state's economy, and each boat contributes over $8,600 a year in economic 

activity. When factoring in boats that simply visit Maryland (are not registered in MD), boating’s 

total impact on the Maryland economy for 2006 was estimated at approximately $2.0 billion with 

over 34,500 jobs provided.

4.6.3 POPULATION AND HOUSING

The residential subsector of the construction industry comprises over one-third of the overall 

construction acreage subject to the proposed CGP. EPA considered potential increases in the cost of 

housing construction and resulting price (or rent) of housing. For the C&D Rule EPA performed a 

regional-level analysis (i.e., level of Metropolitan Statistical Areas , or MSAs) to estimate the 

number and fraction of potential single-family home buyers whose purchasing decisions may be 

affected by the potential increase in the price of newly constructed, single-family housing. 

An MSA-level affordability analysis is preferred to regional- or national-level analyses because it 

captures the high variability in housing market prices and household incomes across and within 

states. For this analysis, EPA used MSA-level single-family new home prices and household 

income distributions to determine the number of prospective home-purchasing households that are 

at or above the income level estimated to be necessary to qualify for the financing of a newly 

constructed single-family home. The results of the analysis at the national level were calculated by 

aggregating the number of potentially affected households across the MSAs in each state and are 

summarized in Table 4-16. Results of this analysis, unmodified, are applicable to the potential 

effects of the CGP because of the MSA-level analysis. 

Table 4-16. National Results from the MSA-Level Affordability Lowest New Home Price AnalysisPrice and Household Affordability Effects

Weighted Average baseline Lowest New Home Price $100,000 

National Average Price Change per New SingleFamily Home Price Change / Percentage Change $130.19 / 0.14% 

Number of Households Whose Purchasing 

Decision for a New Single-Family Lowest Priced 

Home Would be Affected by a Permit-Induced 

Increase in Housing Prices 

Number of Households 680 

Percentage of SF home buyers 

qualifying for the new, in-scope 

lowest-priced home 0.03% 

Percentage of SF home buyers 

qualifying for the lowest-priced home 0.01% 

Number of Affected Households (from above), 

Adjusted to Account for Estimated Number of 

Households Whose Empirically Observed 

Purchase Terms Indicate Ability to Increase 

Housing Payments and Remain Under 29% 

Housing Payment-to-Income Ratio 

Number of Households 324 

Percentage of SF home buyers 

qualifying for the new, in-scope, 

lowest-priced home 0.02% 

Percentage of SF home buyers 

qualifying for the lowest-priced home 0.00% 

Source: EPA 2009b 

A number of studies, however, have identified benefits that decreasing sedimentation and turbidity 

can have that positively affect housing process. For example, aesthetic degradation of land and 

water resources resulting from sediment and other pollutant discharges (e.g., increased water 
Construction and Development NPDES General Permit Environmental Assessment 

80 

turbidity) can reduce the market value of property and thus affect the financial status of property 

owners: hedonic price study by Bejranonda et al. (1999) found that “the rate of sediment inflow 

entering the lakes has a negative influence on lakeside property rent.” 

Sediment discharges also have an impact on stream morphology, e.g., higher coarse sediment loads 

increase river bed width and resulting bank erosion (Wheeler et al. 2003). A 1993 study of Lake 

Erie’s housing market found that “erosion-prone lakeshore property will be discounted” (Kriesel et 

al. 1993). Stabilization of stream banks leads to an increase in the value of surrounding property 

(Streiner and Loomis 1996). Therefore, the final regulation is expected to enhance nearby property 

value in two ways: (1) by improving the aesthetic quality of land and water resources (e.g., reduced 

turbidity) and (2) by improving stream morphology and stabilizing river banks (USEPA, 2009b) 

Due to data limitations, EPA did not estimate changes in market values of properties located near 

water bodies expected to benefit from reduced sediment discharges from construction sites as a 

result of this regulation. Also, the nonmarket component (i.e., increased satisfaction with the 

property) may be implicitly accounted for the willingness-to-pay for improvements in 

environmental services provided by surface waters affected by construction site discharges. 

4.6.4 DEMOGRAPHICS

For the C&D Rule, EPA assessed those areas that are more or likely to have construction activity. 

For the most part, the greatest amount of change is in and around urban areas and benefit both the 

urban economically disadvantaged as well as the more affluent, middle class suburban residents. If 

this generalization is widely valid, certain groups will be more or less exposed to the costs and 

benefits from the proposed CGP. For example, this generalization is more likely to hold for those 

states covered under the proposed CGP where EPA has general permit authority, but less likely to 

hold in other areas covered by the proposed CGP, e.g., tribal lands and territories. In these latter 

areas, development is less likely and the expected impacts, both positive and negative, relatively 

less. In either case, however, there does not appear to be any disproportionate distribution of either 

costs or benefits among various demographic categories potentially affected by the proposed CGP. 

An indirect demographic affect may be the increased house prices as construction companies pass 

on the cost of permit compliance to the consumers in the form of higher housing prices. This may 

discourage those populations that are marginally capable of qualifying for new housing financing 

and could skew the buyers’ demographics to those with greater economic means. A more in depth 

analysis of housing prices was presented above in Section 4.6.3. 

4.6.5 CULTURAL RESOURCES

To address potential impacts to cultural resources from the proposed action in a programmatic 

approach, which is needed when issuing a general permit, EPA is coordinating with the Advisory 

Council on Historic Preservation (ACHP) concerning approaches to compliance with the NHPA. 

4.6.6 CUMULATIVE IMPACTS

Similar to the discussions on cumulative impacts presented above, the proposed re-issuance of the 

CGP on physical resources intrinsically addresses cumulative impacts for several reasons. One 

reason is that the proposed CGP explicitly addresses cumulative impacts by evaluating impacts, 
Construction and Development NPDES General Permit Environmental Assessment 

81 

costs, and benefits at the Agency’s best estimate of projected industry activity that will occur under 

the proposed general permit. A second reason is that EPA has addressed the entire span of C&D 

industry activity, i.e., from the level of individual sites to aggregated industry activity and by 

addressing the entire span of environments most affected by stormwater discharges from C&D 

sites, e.g., streams, rivers, lakes and estuaries. Furthermore, EPA has addressed individual sitespecific concerns by incorporating specific features into the permitting process, e.g., the prohibition 

of coverage for C&D sites discharging to a waterbody impaired for sediment, sediment-related 

pollution, or nutrients, or regional notification of applications to review the potential for a site to 

affect threatened or endangered species, historic resources, or culturally valuable resources. By 

incorporating such protections into the NOI process, EPA has ensured “no significant cumulative 

effect” will occur because the process for obtaining coverage has been developed with specific, 

appropriate, conditions and requirements that anticipate the consequences of multiple C&D sites as 

each individual application is received and reviewed. 

 
Construction and Development NPDES General Permit Environmental Assessment 

82 

5. OTHER CONSIDERATIONS 

5.1 CONSISTENCY WITH OTHER FEDERAL, STATE, AND LOCAL PLANS, 

POLICIES, AND REGULATIONS 

The scope of EPA’s environmental review includes the requirements of Federal statutes and 

policies other than the NPDES permit program. EPA has reviewed the proposed CGP with respect 

to a number of these other Federal statutes and policiesEPA has identified those statutes and 

policies that the proposed CGP may potentially affect, and EPA addresses the consistency of the 

proposed CGP with these statutes and policies in this section as described below. 

5.1.1 CLEAN WATER ACT §401 WATER QUALITY CERTIFICATION BY STATE WATER 

QUALITY AGENCIES

States adopt surface water quality standards pursuant to Section 303 of the CWA. All permits for 

discharges to the navigable waters of the US must include effluent limitations at least as stringent as 

needed to maintain established beneficial uses and to attain the quality of water designated by states 

for their water. Under Section 401 of the CWA, a state has the authority to grant or deny 

“certification” for any discharge originating in that state from a federally permitted or licensed 

facility or activity. If a state denies certification, the Federal permitting or licensing agency is 

prohibited from issuing a permit or license. 

The proposed CGP will comply with the requirements of CWA Section 401 because the proposed 

CGP will be submitted to the affected states and tribes prior to finalization. Part 10 of the proposed 

CGP will include any additional permit conditions required by states and tribes that result from the 

401 certification process. The provisions of Part 10 provide modifications or additions to the 

applicable conditions of the permit to reflect specific additional conditions required as part of the 

state or tribal CWA Section 401 certification process, or the Coastal Zone Management Act 

(CZMA) certification process, or as otherwise established by the permitting authority. The specific 

additional revisions and requirements will only apply to activities in those specific states, Indian 

lands, and federal facilities. States, Indian lands, and federal facilities that are not included in Part 

10 have no modifications or additions required in the final CGP. 

5.1.2 ENDANGERED SPECIES ACT OF 1973 

The Endangered Species Act of 1973 (ESA) establishes a national policy to protect and conserve 

threatened and endangered species and the ecosystems upon which they depend. The ESA is 

administered by the FWS and the NMFS. Section 7 of the ESA governs interagency cooperation 

and consultation. Based on information in Chapter 4 on the provisions, the eligibility criteria built 

into the proposed permit and their reduction of impacts to water quality from stormwater discharges 

from construction activities on T & E species, EPA concludes that the proposed action will not have 

a significant adverse affect on threatened and endangered species or critical habitat present in the 

coverage area of the proposed CGP. 

5.1.3 SECTION 106 OF THE NATIONAL HISTORIC PRESERVATION ACT 

EPA is subject to Section 106 of the National Historic Preservation Act of 1966 and 1996 (NHPA; 

16 U.S.C 470). Under Section 106 of the National Historic Preservation Act and its implementing 

regulations at 36 CFR Part 800 and EO 11593, Federal agencies must take into account effects of 

their undertakings on historic properties listed on or eligible for listing on the National Register of 
Construction and Development NPDES General Permit Environmental Assessment 

83 

Historic Places. Currently, more than 80,000 properties have been listed in the National Register. 

Together these records hold information on more than 1.4 million individual resources--buildings, 

sites, districts, structures, and objects. 

Additionally, the proposed action covers many of the tribal lands within the United States. Tribal 

lands in particular have unique cultural resources that are vulnerable to development and 

construction activities. EPA recognizes that local governments and tribal councils are the best 

source of identifying cultural resources within their communities. 

To address potential impacts to cultural resources from the proposed action in a programmatic 

approach, which is needed when issuing a general permit, EPA is coordinating with the ACHP 

concerning approaches to compliance with the NHPA. 

5.1.4 ENVIRONMENTAL JUSTICE

Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations 

and Low-Income Populations directs Federal agencies to identify and address, as appropriate, 

disproportionately high and adverse health or environmental effects of their programs, policies, and 

activities on minority populations and low-income populations. Environmental justice refers to the 

―fair treatment and meaningful involvement of all people regardless of race, color, national origin, 

or income with respect to the development, implementation, and enforcement of environmental 

laws, regulations, and policies. 

EPA has incorporated requirements into the proposed CGP that will decrease sedimentation and 

turbidity effects to surface waters. No high and adverse health or environmental effects, to either 

the general population, or minority and low-income populations, are expected from issuance of the 

CGP. 

 
Construction and Development NPDES General Permit Environmental Assessment 

84 

6. REFERENCES 

Aicardo, R. 1996. Screening of Polymers to Determine Their Potential Use in Erosion Control on 

Construction Sites. In Proceedings from Conference held at College of Southern Idaho: 

Managing Irrigation-Induced Erosion and Infiltration with Polyacrylamide, May 6-8, 1996, 

Twin Falls, ID. University of Idaho Miscellaneous Publication No. 101-96. 

Alexander, R. 2003. Standard Specifications for Compost for Erosion/Sediment Control, developed 

for the Recycled Materials Resource Center , University of New Hampshire, Durham, New 

Hampshire. Available at: www.alexassoc.net

Area Wide Soil Contamination Task Force. 2003. Area Wide Soil Contamination Task Force 

Report Submitted to: Washington State Department of Agriculture, Washington State 

Department of Ecology, Washington State Department of Health, Washington State 

Department of Community, Trade and Economic Development. June 30, 2003. 

Barton, B.A. 1977. “Short-term effects of highway construction on the limnology of a small stream 

in southern Ontario.” Freshwater Biology 7: 99-108. 

Bejranonda, S. F.J. Hitzhusen; and D. Hite. 1999. “Agricultural Sedimentation Impacts on Lakeside 

Property Values.” Agricultural and Resource Economics Review 28(2): 208-18. 

Berry, W., N. Rubinstein, B. Melzian, and B. Hill. 2003. The Biological Effects of Suspended and 

Bedded Sediment (SABS) in Aquatic Systems: A Review. Internal Report of the U.S. EPA 

Office of Research and Development. Narragansett, RI. Available at 

http://www.epa.gov/waterscience/criteria/sediment/appendix1.pdf

Bilotta, G.S. and R.E. Brazier. 2008. “Understanding the influence of suspended solids on water 

quality and aquatic biota.” Water Research 42: 2849-2861. 

Blanco, H., D. Carlson, M. Chalana, F. Wagner, and C. Wolfe. 2009. Final Report Linking Toxics 

Cleanup and Redevelopment Across the States: Lessons for Washington State. Prepared for 

The Toxics Cleanup Program, Washington State Department of Ecology. 

Boardman, A.E., D.H. Greenberg, A.R. Vining, and D.L. Weimer. 2001. Cost-Benefit Analysis: 

Concepts and Practice, 2nd edition. Upper Saddle River, NJ: Prentice Hall. 

Caine, E. 2001. Quilceda-Allen Watershed Erosion Control Program, Water Quality Monitoring 

Report, Snohomish County, Washington, Department of Planning and Development Services, 

Building Division. 

California Straw Works. 2005. Straw Wattles. (http://www.strawwattles.com/index.html). 

Canadian Council of Ministers of the Environment (CCME). 2001. Canadian water quality 

guidelines for the protection of aquatic life: CCME Water Quality Index 1.0, Technical 
Construction and Development NPDES General Permit Environmental Assessment 

85 

Report. In: Canadian environmental quality guidelines, 1999, Canadian Council of Ministers 

of the Environment, Winnipeg. 

Carruthers, T. and Wazniak, C. 2003. Development of a Water Quality Index for the Maryland 

Coastal Bays. Maryland’s Coastal Bays: Ecosystem Health Assessment, Chapter 4.4. 2003. 

Chapra, S.C. 1997. Surface water-quality modeling. McGraw-Hill, New York. 844 p. As cited in 

Schwarz et al. 2006. 

Clark, E., J.A. Haverkamp, and W.Chapman. 1985. “Eroding Soils: The Off-Farm Impacts.” 

Washington, DC: The Conservation Foundation. 

Claytor, R. 1997. Practical Tips for Constrcution Site Phasing. Article Number 54 in The Practice 

of Watershed Protection. Center for Watershed Protection, Ellicott City, MD. 2000. 

Claytor, R., and T. Schueler. 1996. Design of Stormwater Filtering Systems. Center for Watershed 

Protection, Silver Spring, MD. 

Cude, C. G. 2001. Oregon Water Quality Index: “A Tool for Evaluating Water Quality 

Management Effectiveness.” Journal of the American Water Resources Association 

37(1):125-137. 

DeZuane, John. 1997. Handbook of Drinking Water Quality, 2nd Ed. New York: John Wiley & 

Sons. 

Earth Saver Erosion Control Products. 2005. Rice Straw Wattles. (http://www.earthsavers.com/pages/applictn.html#Anchor-Capture-47857 ). Accessed May 19, 

2005. 

Faucette, B. 2004. Evaluation of Environmental Benefits and Impacts of Compost and Industry 

Standard Erosion and Sediment Controls Measures Used in Construction Activities, 

Dissertation, Institute of Ecology, University of Georgia, Athens, Georgia. 

Faucette, B. and M. Risse. 2002. Controlling Erosion with Compost and Mulch. BioCycle, June 

2002, pages 26–28. 

Faucette L.B., J. Governo, C.F. Jordan, B.G. Lockaby, H.F. Carino, and R. Governo. 2007. 

“Erosion control and storm water quality from straw with PAM, mulch, and compost blankets 

of varying particle sizes.” Journal of Soil and Water Conservation 62(6): 404-413. 

Fifeld, J.S. 1999. When best management practices become "bad management practices." In 

International Erosion Control Association Proceedings of Conference 30, February 22-26, 

1999, Nashville, Tennessee, p. 189-203. 

Fifield, J. 1999b. Designing Effective Sediment and Erosion Control for Construction Sites. 

Forester Press, Santa Barbara, CA.
Construction and Development NPDES General Permit Environmental Assessment 

86 

Folkes, D.J., S.O. Helgen, and R.A. Litle. 2001. “Impacts of Historic Arsenical Pesticide Use on 

Residential Soils in Denver, Colorado.” In: Proc. 4th Int. Conf. On Arsenic Exposure and 

Health Effects, SanDiego. 

Gilliam, J.W. 1994. Reparian Wetlands and Water Quality. Journal of Environmental Quality

23:896-900. Cited in Michigan Department of Environmental Quality. 1998. Guidebook of 

Best Management Practices for Michigan Watersheds. Michigan Department of 

Environmental Quality, Surface Water Quality Division, Lansing, MI. 

Glanville et al. 2003. Impacts of Compost Blankets on Erosion Control, Revegetation, and Water 

Quality at Highway Construction Sites in Iowa, T. Glanville, T. Richard, and R. Persyn, 

Agricultural and Biosystems Engineering Department, Iowa State University of Science and 

Technology, Ames, Iowa. 

Gupta, A.K., Gupta, S.K., and Patil, R.S. 2003. “A Comparison of Water Quality Indices for 

Coastal Water.” Journal of Environmental Science and Health 38(11): 2711-2725. 2003. 

Harding, M.V. 1990. Erosion Control Effectiveness: Comparative Studies of Alternative Mulching 

Techniques. Environmental Restoration, pp. 149-156, as cited in USEPA. 1993. Guidance 

Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters. EPA 

840-B-92-002. U.S. Environmental Protection Agency, Office of Water, Washington, DC. 

Hedrick, K.P., R.B. Robinson, B. Tschantz, and S.E. Moore. 2006. “Impact of Tunnel 

Reconstruction on Stream Water Quality in Great Smoky Mountains National Park.” Journal 

of Hydrologic Engineering 11(6): 570-577. 

Heyer, T. No Date. Vegetative Measures for Streambank Stabilization. U.S. Department of 

Agriculture, U.S. Forest Service, St, Paul, MN.

Kerr, S. J. 1995. Silt, Turbidity and Suspended Sediments in the Aquatic Environment: An 

Annotated Bibliography and Literature Review. Ontario Ministry of Natural Resources, 

Southern Region Science & Technology Transfer Unit Technical Report TR-008. 

Kriesel, W., A. Randall, and F. Lichtkoppler. 1993. “Estimating the Benefits of Shore Erosion 

Protection in Ohio’s Lake Erie Housing Market.” Water Resources Research. 29(4). 795-801. 

Livingston. 1997. Operation, Maintenance, and Management of Stormwater Management Systems. 

Watershed Management Institute, Ingleside, MD. 

McCoy, S. 2005. Filter Sock Presentation provided at Erosion, Sediment Control and Stormwater 

Management with Compost BMPs Workshop, U.S. Composting Council 13th Annual 

Conference and Trade Show, January 2005, San Antonio, Texas. 

Miller, D.A., and R.A. White. 1998. A conterminous United States multilayer soil characteristics 

data set for regional climate and hydrology modeling. Earth Interactions 2(2):1–26.
Construction and Development NPDES General Permit Environmental Assessment 

87 

MWCOG (Metropolitan Washington Council of Governments). 1992. A Current Assessment of 

Urban Best Management Practices: Techniques for Reducing Non-Point Source Pollution in 

the Coastal Zone. Metropolitan Washington Council of Governments, Department of 

Environmental Programs, Washington, DC. 

National Marine Fisheries Service (NMFS). 2011a. Endangered Species Act. Available at: 

 http://www.nmfs.noaa.gov/pr/laws/esa/. Accessed August 2011. 

National Research Council (NRC). 2008. Urban Stormwater Management in the United States. 

Washington, D.C.: National Academies Press. 553 pp. 

New Jersey Department of Environmental Protection (DEP). 1999. Findings and Recommendations 

for the Remediation of Historic Pesticide Contamination. Historic Pesticide Contamination 

Task Force. 

Ngo, D. and J. Nichols. 1998. Design of Sedimentation Basins. Water Treatment Primer: CE 4124: 

Environmental Information Management. Civil Engineering Department, Virginia Tech. 

Accessed September 29, 2008. Available at 

http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/sedimen/sedimen.html. 

Osterkamp, W.R., P. Heilman, and L.J. Lane. 1998. “Economic Considerations of a Continental 

Sediment-monitoring Program.” International Journal of Sediment Research 13(4): 12-24. 

Paul, M.J. and J.L. Meyer. 2001. “Streams in the Urban Landscape.” Annual Review of Ecology and 

Systematics 32: 333-65.

Reid, S.M., G. Isaac, S. Metikosh and J. Evans. 2003. “Physiological Response of Rainbow Trout 

to Sediment Released during Open-Cut Pipeline Water Crossing Construction.” Water Quality

Resources Journal of Canada 38(3): 473-481. 

Renshaw, C.E., B.C. Bostick, X. Feng, C.K. Wong, E.S. Winston, R. Karimi, C.L. Folt, and C.Y. 

Chen. 2006. “Impact of Land Disturbance on the Fate of Arsenical Pesticides.” Journal of

Environmental Quality 35: 61-67. 

Renwick, W.H., S.V. Smith, J.D. Bartley, and R.W. Buddemeier. 2005. “The role of impoundments 

in the sediment budget of the conterminous United States.” Geomorphology 71(1-2): 99-111. 

Robinson, G.R., P. Larkins, C.J. Boughton, B.W. Reed, and P.L. Sibrell. 2007. “Assessment of 

Contamination from Arsenical Pesticide Use on Orchards in the Great Valley region, 

Virginia and West Virginia, USA.” Journal of Environmental Quality 36: 654-663. 

Seattle and King County Public Health. 2001. Vashon/Maury Island Soil Study 1999-2000, Final 

Report. 

Schwarz, G.E (USGS). 2008a. A Preliminary SPARROW model of suspended sediment for the 
Construction and Development NPDES General Permit Environmental Assessment 

88 

conterminous United States: U.S. Geological Survey Open-File Report 2008–1205, 8 p., 

Available at http://pubs.usgs.gov/of/2008/1205

Smith, R.A., G.E. Schwarz, and R.B. Alexander. 1997. “Regional interpretation of water-quality 

monitoring data.” Water Resources Research 33: 2781-2798. As cited in Schwarz et al. 

2006. 

Smolen, M.D., D.W. Miller, L.C. Wyall, J. Lichthardt, and A.L. Lanier. 1988. Erosion and 

Sediment Control Planning and Design Manual. North Carolina Sedimentation Control

Commission and North Carolina Department of Natural Resources and Community

Development, Raleigh, NC.

Stone, D. and K. Anderson. 2009. Yesterday’s Orchard... Today’s Home: Legacy Pesticides on 

Former Orchard Properties. Oregon State University Extension Service. EC1513-E. 

Streiner, C.F. and Loomis, J.B. 1996. “Estimating the Benefits of Urban Stream Restoration Using 

the Hedonic Price Method.” Rivers. 5(4): 267-278. 

Tyler, R. and B. Faucette. 2005. Organic BMPs used for Stormwater Management—Filter Media 

Test Results from Private Certification Program Yield Predictable Performance, U.S. 

Composting Council 13 th Annual Conference and Trade Show, January 2005, San Antonio, 

Texas. 

U.S. Army Corps of Engineers. 2009. Inland Waterway Navigation, Value to the Nation. 

http://www.iwr.usace.army.mil/docs/VTN/VTNInlandNavBro_lores.pdf 

U.S. Census Bureau. 2000. 2000 Urbanized Areas Cartographic Boundary Files. U.S. Census 

Bureau, Washington, DC. <http://www.census.gov/geo/www/cob/ua2000.html.>. Accessed 

January 2008. 

U.S. Census Bureau. 2005a. 2002 Economic Census: Construction. Various Reports. Available 

online at: http://www.census.gov/econ/census02/guide/INDRPT23.HTM 

USDA (U.S. Department of Agriculture). 2006, Major Uses of Land in the United States, 2002. 

Electronic report found at: http://www.ers.usda.gov/Publications/EIB14/)

USDA (U.S. Department of Agriculture). 2007. U.S. General Soil Map (STATSGO) (Database). 

U.S. Department of Agriculture, Natural Resources Conservation Service, Washington, DC. 

<http://soildatamart.nrcs.usda.gov/USDGSM.aspx>. Updated July 11, 2007. 

U.S. Environmental Protection Agency (USEPA). 1992. Stormwater Management for Industrial 

Activities: Developing Pollution Prevention Plans and Best Management Practices. U.S. 

Environmental Protection Agency, Washington, DC. 
Construction and Development NPDES General Permit Environmental Assessment 

89 

U.S. Environmental Protection Agency (USEPA). 1993. Guidance Specifying Management 

Measures for Sources of Nonpoint Pollution in Coastal Waters. EPA 840-B-92-002. U.S. 

Environmental Protection Agency, Office of Water, Washington, DC. 

U.S. Environmental Protection Agency (USEPA). 1998. An Analysis of Composting as an 

Environmental Remediation Technology. U.S. Environmental Protection Agency, Solid 

Waste and Emergency Response (5305W), EPA530-R-98-008, April 1998. 

U.S. Environmental Protection Agency (USEPA). 2004b. Development Document for Final Action 

for Effluent Guidelines and Standards for the Construction and Development Category. 

EPA-821-B-04-001. 

U.S. Environmental Protection Agency (USEPA). 2007a. Aquatic Life Ambient Freshwater Quality 

Criteria-Copper: 2007 Revision. Office of Water. EPA-822-R-07-001. Feb. 2007. 

U.S. Environmental Protection Agency (USEPA). 2007b. “Identification and Characterization of 

Typical Drinking Water Treatment Residuals.” Peer Involvement for the Drinking Water 

Treatment Effluent Guidelines. September 2007. 

U.S. Environmental Protection Agency (USEPA). 2007e. U.S. EPA Reach File 1 (RF1) for the 

Conterminous United States in BASINSRF1. Available at: 

http://www.epa.gov/waterscience/BASINS/metadata/rf1.htmMetadata_Reference_Information. 

U.S. Environmental Protection Agency (USEPA). 2008. An Introduction to Freshwater Fishes as 

Biological Indicators, EPA No. 260-R-08-016. Available at: 

http://www.epa.gov/bioiweb1/pdf/EPA-260-R-08-

016AnIntroductiontoFreshwaterFishesasBiologicalIndicators.pdf 

U.S. Environmental Protection Agency (USEPA). 2009a. Development Document for Proposed 

Effluent Guidelines and Standards for the Construction and Development Category. EPA821-R-08-007. 

U.S. Environmental Protection Agency (USEPA). 2009b. Environmental Impact and Benefits 

Assessment for Final Effluent Guidelines and Standards for the Construction and 

Development Category. November 2009. EPA-821-R-09-012 

U.S. Environmental Protection Agency (USEPA). 2009c. Economic Analysis of Proposed Effluent 

Guidelines and Standards for the Construction & Development Industry. November 23, 

2009. EPA-821-R-08-008. 

U.S. Environmental Protection Agency (USEPA). 2011a. Construction Site Stormwater Runoff 

Control. Available at: 

http://cfpub.epa.gov/npdes/stormwater/menuofbmps/index.cfm?action=min_measure&min_

measure_id=4
Construction and Development NPDES General Permit Environmental Assessment 

90 

U.S. Environmental Protection Agency (USEPA). 2011b. Drinking Water Program website. 

Available at: http://water.epa.gov/infrastructure/drinkingwater/pws/factoids.cfm

U.S. Fish and Wildlife Service (USFWS). 2011a. Endangered Species Program: Species 

Information. Available at http://www.fws.gov/endangered. Accessed August 2011. 

U.S. Geological Survey (USGS). 2007b. National Hydrography Dataset (NHD). Available at 

http://nhd.usgs.gov/data.html

VDCR (Virginia Department of Conservation and Recreation). 1995. Virginia Erosion & Sediment 

Control Field Manual. 2nd ed. Virginia Department of Conservation and Recreation, 

Division of Soil and Water Conservation, Richmond, VA. 

Vice, R.B., H.P. Guy, and G.E. Ferguson (USGS). 1969. Sediment Movement in an Area of 

Suburban Highway Construction, Scott Run Basin, Fairfax County, Virginia, 1961-64. 

Geological Survey Water-Supply Paper 1591-E. U.S. Government Printing Office.

W&H Pacific. 1993. Demonstration Project Using Yard Debris Compost for Erosion Control, 

Final Report, presented to Metropolitan Service District, Portland, Oregon. 

Washington State Department of Ecology. 1992. Stormwater Management Manual for the Puget 

Sound Basin. Washington State Department of Ecology, Olympia, WA. 

Waters, T. F. 1995. Sediment in Streams: Sources, Biological Effects, and Control. Bethesda, MD; 

American Fisheries Society Monograph 7. 

Wheeler, A.P., A.E. Keiter Rosenberger and P.L. Angermeier. 2003. Potential Impacts of I-73 on 

Stream Habitat and Biota,with Emphasis on the Federally Endangered Roanoke Logperch. 

Department of Fisheries and Wildlife services, Virginia Polytechnic Institute and State 

University. 

Wolman, M.C., and A.P. Schick. 1967. “Effects of Construction on Fluvial Sediment, Urban and 

Suburban Areas of Maryland.” Water Resources Research 3(2): 451-464. 

Wolock, D.M. 1997. STATSGO soil characteristics for the conterminous United States: 

U.S. Geological Survey Open-File Report 97-656. U.S. Geological Survey, Reston, VA. 

<http://water.usgs.gov/GIS/metadata/usgswrd/muid.html>. Accessed December 2007. 

Yao, K.M. (ASCE). 1975. “Extended Plain Sedimentation.” Journal of the Environmental 

Engineering Division 101(3): 413-423. 

Yorke, Thomas H., and William J. Herb (USGS). 1978. Effects of Urbanization on Streamflow and 

Sediment Transport in the Rock Creek and Anacostia River Basins, Montgomery County, 

Maryland, 1962-74. Geological Survey Professional Paper 1003. 

 
Construction and Development NPDES General Permit Environmental Assessment 

91 

APPENDIX A 

NATIONAL LAND COVER DATABASE DEVELOPMENT CHANGE, BY EPA REGION 

Figure 1. EPA Region 1 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

92 

Figure 2. EPA Region 2 - Percentage urban change 1992–2001 by ERF1_2 watershed

Figure 3. EPA Region 3 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

93 

\ 

Figure 4. EPA Region 4 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

94 

Figure 5. EPA Region 5 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

95 

Figure 6. EPA Region 6 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

96 

Figure 7. EPA Region 7- Percentage urban change 1992–2001 by ERF1_2 Watershed
Construction and Development NPDES General Permit Environmental Assessment 

97 

Figure 8. EPA Region 8 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

98 

Figure 9. EPA Region 9 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

99 

Figure 10. EPA Region 10 - Percentage urban change 1992–2001 by ERF1_2 watershed 
Construction and Development NPDES General Permit Environmental Assessment 

100