Review of the EPA’s Economic Analysis of Final Water Quality 

Standards for Nutrients for Lakes and Flowing Waters in Florida 

 

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NOT FOR PUBLIC RELEASE BEFORE 

March 6, 2012 

11:00 a.m. EST 

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Review of the EPA’s Economic Analysis of Final Water Quality 

Standards for Nutrients for Lakes and Flowing Waters in Florida 

Committee to Review EPA's Economic Analysis of Final Water Quality Standards for 

Nutrients for Lakes and Flowing Waters in Florida 

Water Science and Technology Board 

Division on Earth and Life Studies 

THE NATIONAL ACADEMIES PRESS 

Washington, D.C. 

www.nap.edu 
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EP-C-09-003, task order 15. Any opinions, findings, conclusions, or recommendations 

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COMMITTEE TO REVIEW EPA’S ECONOMIC ANALYSIS OF 

FINAL WATER QUALITY STANDARDS FOR NUTRIENTS 

FOR LAKES AND FLOWING WATERS IN FLORIDA 

GLEN T. DAIGGER, Chair, CH2M Hill, Englewood, Colorado 

OTTO C. DOERING, Vice Chair, Purdue University, West Lafayette, Indiana 

LEONARD A. SHABMAN, Vice Chair, Resources for the Future, Arlington, Virginia 

WALTER L. BAKER, Utah Division of Water Quality, Salt Lake City 

ALLEN P. DAVIS, University of Maryland, College Park 

K. WILLIAM EASTER, University of Minnesota, St. Paul 

WENDY D. GRAHAM, University of Florida, Gainesville 

ARTURO A. KELLER, University of California, Santa Barbara 

DAVID J. MULLA, University of Minnesota, St. Paul 

KEVIN M. SHERMAN, Quanics, Inc., Crestwood, Kentucky 

KURT STEPHENSON, Virginia Polytechnic Institute and State University, Blacksburg 

MICHAEL B. TATE, Kansas Department of Health and Environment, Topeka 

ALAN H. VICORY, Ohio River Valley Water Sanitation Commission, Cincinnati, Ohio 

LAJUANA S. WILCHER, English, Lucas, Priest, & Owsley, L.L.P., Bowling Green, Kentucky 

NRC STAFF 

LAURA J. EHLERS, Study Director 

JEFFREY JACOBS, Scholar 

MICHAEL J. STOEVER, Research Associate 

ANITA A. HALL, Senior Program Associate 
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WATER SCIENCE AND TECHNOLOGY BOARD 

DONALD I SIEGEL, Chair, Syracuse University, New York 

LISA ALVAREZ-COHEN, University of California, Berkeley 

EDWARD J. BOUWER, Johns Hopkins University, Baltimore, Maryland 

YU-PING CHIN, Ohio State University, Columbus 

OTTO C. DOERING, Purdue University, West Lafayette, Indiana 

M. SIOBHAN FENNESSY, Kenyon College, Gambier, Ohio 

BEN GRUMBLES, Clean Water America Alliance, Washington, D.C. 

GEORGE R. HALLBERG, The Cadmus Group, Watertown, Massachusetts 

KENNETH R. HERD, Southwest Florida Water Management District, Brooksville, Florida 

GEORGE M. HORNBERGER, Vanderbilt University, Nashville, Tennessee 

KIMBERLY L. JONES, Howard University, Washington, D.C. 

LARRY LARSON, Association of State Floodplain Managers, Madison, Wisconsin 

DAVID H. MOREAU, University of North Carolina, Chapel Hill 

DENNIS D. MURPHY, University of Nevada, Reno 

MARYLYNN V. YATES, University of California, Riverside 

STAFF 

JEFFREY JACOBS, Director 

LAURA J. EHLERS, Senior Program Officer 

STEPHANIE E. JOHNSON, Senior Program Officer 

LAURA E. HELSABECK, Senior Program Officer 

M. JEANNE AQUILINO, Financial and Administrative Associate 

ANITA A. HALL, Senior Program Associate 

MICHAEL J. STOEVER, Research Associate 

SARAH E. BRENNAN, Senior Program Assistant 
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Acknowledgment of Reviewers 

 This report has been reviewed in draft form by individuals chosen for their diverse 

perspectives and technical expertise, in accordance with procedures approved by the National 

Research Council’s Report Review Committee. The purpose of this independent review is to 

provide candid and critical comments that will assist the institution in making its published 

report as sound as possible and to ensure that the report meets institutional standards for 

objectivity, evidence, and responsiveness to the study charge. The review comments and draft 

manuscript remain confidential to protect the integrity of the deliberative process. We wish to 

thank the following individuals for their review of this report: 

ROBERT K. DAVIS, University of Colorado, Boulder (emeritus) 

PATRICK L. BREZONIK, University of Minnesota, Minneapolis (emeritus) 

ROBIN K. CRAIG, Florida State University, Tallahassee 

ANDREW FISK, Connecticut River Watershed Council, Greenfield, Massachusetts 

J. WALTER MILON, University of Central Florida, Orlando 

PATRICIA E. NORRIS, Michigan State University, East Lansing 

DAVID E. RADCLIFFE, University of Georgia, Athens 

DAVID STENSEL, University of Washington, Seattle 

ROBERT G. TRAVER, Villanova University, Villanova, Pennsylvania 

MYRON F. UMAN, Science and Technology for Public Policy LLC, West Palm Beach, Florida 

 Although the reviewers listed above have provided many constructive comments and 

suggestions, they were not asked to endorse the conclusions or recommendations nor did they 

see the final draft of the report before its release. The review of this report was overseen by

Robert A. Frosch, Harvard University and John J. Boland, Johns Hopkins University. 

Appointed by the National Research Council, they were responsible for making certain that an 

independent examination of this report was carried out in accordance with institutional 

procedures and that all review comments were carefully considered. Responsibility for the final 

content of this report rests entirely with the authoring committee and the institution. 
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Contents 

SUMMARY 1 

1 INTRODUCTION 10 

 Technical Challenges of Nutrient Management in Florida, 10 

Impairment of Florida’s Inland Streams, Lakes, and Springs, 16

 Water Quality Standards and the TMDL Process, 20

 Numeric Nutrient Criteria in Florida, 23

 Request for National Research Council Study, 27

 References, 29 

2 ASSESSMENT AND COMMENTARY ON EPA’S ANALYSIS 32 

 EPA Cost Analysis Methods: Overview, 32

 Sector Cost Assessments, 41

 Findings and Recommendations, 70

 References, 74

3 A FRAMEWORK FOR INCREMENTAL COST ANALYSIS 79

OF A RULE CHANGE 

 Introduction, 79

 Comparing the Narrative and Numeric Nutrient Criteria Rules, 80

 A Cost Analysis Framework, 87

 Transparency and Dispute Resolution Under the Proposed Framework, 99

 Findings, 101

 References, 102

ACRONYMS 103

 

APPENDIXES 

A Narrative, Numeric, and Proposed Florida Nutrient Criteria Processes 105 

Illustrated

B Biographical Sketches of Committee Members and Staff 112 

 
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Summary 

INTRODUCTION 

Nutrients such as nitrogen and phosphorus have long been known to cause degradation of 

surface waters, as manifested by harmful algal blooms, the loss of submersed aquatic vegetation, 

and fish kills in waterbodies around the country. Stemming from agricultural operations, urban 

landscapes, wastewater, and atmospheric deposition, nutrients pollution often is addressed under 

the Clean Water Act through the use of narrative standards. However, States have recently been 

pushed toward numeric nutrient criteria under the assumption that this will accelerate and 

standardize the restoration of nutrient-impaired waters. In Florida, numeric criteria for nitrogen 

and phosphorus were proposed by the U.S. Environmental Protection Agency (EPA) following a 

2009 lawsuit maintaining that Florida’s narrative standard was not protective of Florida’s waters. 

Replacing the narrative standard with numeric nutrient criteria may result in new Florida 

waters being listed as impaired and the reevaluation of the Total Maximum Daily Load (TMDL) 

calculations for waters that are currently listed as impaired. These actions may lead to new or 

revised discharge permits for point sources such as municipal and industrial wastewater 

treatment plants, and/or nutrient control requirements for nonpoint sources of nutrients. Because 

of these implications, EPA was required to produce an economic analysis of the potential 

incremental implementation costs that might be incurred if numeric nutrient criteria replaced 

Florida’s narrative standard for nutrients. In late 2010, EPA estimated the incremental cost to 

range from $135.5 to $206.1 million per year. Other stakeholder groups produced their own 

estimates of the cost of implementing the numeric nutrient criteria, with some estimating annual 

costs as high as $12 billion.

Shortly after producing its cost estimate, EPA requested that a committee of the National 

Research Council review the Agency’s economic analysis of the incremental costs of state 

implementation of numeric nutrient criteria for lakes and flowing waters in Florida. Specifically, 

the Committee was asked to review and comment on the implications of: 

1. EPA’s assumption that costs should be determined only for waters that will be “newly 

impaired” as a result of the numeric nutrient criteria. 

2. EPA’s decision to estimate the costs of only those sources of pollution that would directly 

affect a “newly impaired” water—in particular the number of wastewater treatment plants, 

the acreage of agricultural land, the acreage of urban areas, and the number of septic systems 

included in the EPA analysis. 
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3. EPA’s assumptions about the levels of control that could be used by certain point and 

nonpoint sources, such as wastewater treatment plants, industrial point sources, agricultural 

activities, and septic systems. Examples of these assumptions could include a decision to 

seek a regulatory exemption, implement reverse osmosis technology, or use conventional 

best management practices (BMPs) rather than more expensive water treatment options. 

Item #1 is addressed primarily in Chapter 3 of this report, while Chapter 2 addresses the second 

and third items. 

Several constraints were placed on the Committee that were necessary in order for it to 

produce its report by March 2012. First, the Committee was not asked to review the numeric 

nutrient criteria themselves. Second, the Committee was not asked to address the benefits of 

implementing the numeric nutrient criteria, such as potential improvement in water quality, nor 

the indirect costs associated with implementing the criteria, such as the number of jobs lost or 

gained, or how certain sectors of the economy will fare under the numeric nutrient criteria. 

Finally, the Committee was not asked to produce its own cost estimate. Rather, the report 

tackles the validity of the assumptions found in the EPA report (and those of various 

stakeholders) and provides findings and recommendations on the methods to be used in any 

future cost analyses. The Committee concluded that EPA was correct to calculate the costs of 

meeting the numeric nutrient criteria on an incremental basis. However, the Committee 

questioned how the incremental effect of the rule was defined by EPA, as described in detail in 

this report. 

Although determining the incremental cost of the rule change (from narrative to numeric) 

was the correct analytical focus for EPA to have taken, presentations made to the Committee and 

later communication from stakeholders often confused the incremental costs of the rule change 

with the total costs to meet the designated uses of impaired waters, under any rule. Many of 

Florida’s thousands of river miles and lakes and hundreds of springs already suffer from chronic 

nutrient pollution because of high population growth rates and resulting demands for water, land 

use changes from wetlands and forests to agriculture and urban areas, the state’s tropical climate 

and flat topography, the potential for soil and geologic materials to serve as sources of nutrients, 

and the buildup of legacy nutrients. These factors have made and will continue to make nutrient 

management in Florida an important but formidable and costly challenge, regardless of the 

regulatory paradigm used. Indeed, the total costs to meet Florida water quality goals will exceed 

the reported incremental costs of the EPA analysis and also may exceed the costs of 

implementing the suite of practices currently used to control point and nonpoint source 

dischargers of nutrients. A statement to this effect from the FDEP could further the public’s 

understanding of the scope of nutrient pollution in Florida and the challenges to its management, 

and overcome misunderstandings that have arisen during debate about EPA’s numeric nutrient 

criteria.

Florida is in the process of trying to develop its own numeric criteria for nutrients that 

would supersede EPA’s, if approved by the Florida Environmental Regulatory Commission, the 

Florida legislature, and EPA. As of the writing of this report, the FDEP has developed a hybrid 

approach that includes aspects of both the narrative and the numeric criteria. Although it is 

unclear whether the newly proposed Florida rule for nutrients will be accepted, the 

recommendations in this report should be useful regardless of what rule is ultimately adopted. 
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REVIEW OF EPA’S COST ANALYSIS 

 Chapter 2 provides the Committee’s assessment of the EPA cost analysis, focusing on the 

efforts made by EPA to (1) identify permitted point sources that would be incrementally affected 

by the numeric nutrient criteria (NNC) rule, (2) define incrementally impaired waters and their 

associated watersheds, and (3) estimate the costs of reducing nutrient loads from those point 

sources and/or to those waters. Costs to comply with the NNC rule were estimated for the 

following sectors: municipal wastewater facilities, industrial wastewater facilities, agriculture 

lands, urban stormwater, and on-site septic systems. The associated costs of governmental 

administration were also estimated. Key assumptions made by EPA include the following: 

 The definition of the incremental effect of the NNC rule was defined and limited to (1) 

waterbodies that would be newly listed and determined to be stressed by nutrients and (2) 

municipal and industrial sources that would receive certain concentration limits in their 

discharge permits; 

 EPA assessed the incremental effect of the NNC rule at a single point in time, assuming 

no further changes would occur under the narrative process, rather than comparing the 

future outcomes of both processes over time; 

 Waters currently listed as impaired based on the narrative criteria (either with or without 

a TMDL) were not considered in the cost analysis, because it was assumed that a TMDL 

exists or would be developed, and that this TMDL would serve as the basis for a sitespecific alternative criteria (SSAC) determination; and 

 Municipal and industrial wastewater treatment plants discharging at 3 mg/L for total 

nitrogen (TN) and 0.1 mg/L for total phosphorus (TP) were considered in compliance 

with the NNC rule. 

Incrementally Impaired Waters and Watersheds

One component of how EPA defined the incremental effect of the NNC rule was to 

estimate the number of new waterbodies that would be in noncompliance with the numeric 

nutrient criteria, as well as to estimate the location and amount of land area that would need 

attention in the form of runoff controls to return those waterbodies to compliance. The following 

findings are made regarding this portion of the EPA analysis: 

It is not valid to assume that the percent of unassessed waters that would be 

incrementally affected is zero. A more defensible approach would take into consideration the 

characteristics of the unassessed waterbodies and their drainage areas to predict the likelihood 

that they would fail to meet the narrative criteria or the numeric nutrient criteria. This 

conclusion has implications for the urban stormwater, agriculture, septic system, and government 

sector analyses.
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The HUC10 delineation used to assess the acreage of various land uses that 

contribute to the potential impairment is too coarse. EPA should use the more refined 

HUC12 delineation to generate a more precise estimate of the acres to consider for BMPs in the 

agricultural and urban stormwater sectors.

Sector Analyses 

 For each sector that discharges to inland waters, EPA’s method for determining the 

incremental cost of the NNC rule was based on calculating the product of (1) the number of 

newly affected units (or area) and (2) the unit cost to “treat” the discharge in those additional 

units. For municipal and industrial point sources, EPA identified the number of point sources 

that would have to improve treatment in response to the NNC rule, made assumptions about the 

technological upgrades that would be necessary, and assigned a cost for the upgrades. For the 

stormwater and agricultural sources, EPA estimated the corresponding acreage draining to the 

potential incrementally impaired waterbodies, reduced the acreage considered based on BMP 

programs that were already in place, selected a set of BMPs deemed to be adequate and costeffective to comply with the NNC rule, and then assigned a unit cost to the resulting acreage to 

estimate the total cost for the two sectors. For septic systems, EPA determined the number of 

systems within 500 feet of a potential incrementally impaired waterbody and multiplied this 

number by the unit cost to upgrade septic systems to reduce their nutrient loads. Government 

costs were based solely on estimates of the administrative costs of developing additional 

TMDLs. 

Municipal Wastewater Treatment Plants 

There is significant uncertainty in the cost estimate for municipal wastewater 

treatment plants. First, the assumption that no plant will be required to treat to levels more 

stringent than 3 mg/L TN and 0.1 mg/L TP is unrealistic. Although it is uncertain what 

proportion of plants will be permitted to treat to 3 mg/L TN and 0.1 mg/L TP, it appears likely 

that at least some plants will have to treat to more stringent levels. Second, there is significant 

uncertainty in the cost estimate for municipal wastewater treatment plants because the unit 

treatment costs were not verified by comparison to the existing and extensive Florida advanced 

wastewater treatment experience. Efforts should be made to compare the unit costs used by EPA 

with cost data from Florida, and also to better estimate the percentage of plants that will be 

required to reach discharge limits more stringent than 3 mg/L TN and 0.1 mg/L TP by 

performing mass balance and dilution calculations for at least a representative proportion of 

plants, if not for all of the plants included in this analysis.

Industrial Plants 

There is significant uncertainty about the incremental cost of the NNC rule for 

industrial plants for several reasons. EPA based its estimates on one or two selected facilities 

from each sector. This extrapolation led to some low-flow facilities exerting a disproportionate 
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influence on the overall industrial costs. Furthermore, the same cost model and treatment 

processes were used for industrial facilities as were employed for municipal plants. For facilities 

with highly variable flows, flow equalization may be a more cost-effective solution than 

mechanical/chemical treatment, such that EPA may have overestimated costs for these facilities. 

On the other hand, some industrial facilities have higher unit costs than municipal plants. 

Finally, industries covered under general permits were not investigated, raising the question of 

whether there may be costs from those facilities that were not captured in EPA’s estimates. 

Given the small number of industries involved, the cost analysis should be improved by 

analyzing each plant rather than extrapolating the results of one or two plants to the entire sector. 

As with the municipal wastewater treatment plants, efforts should be made to compare the unit 

costs used by EPA with cost data from Florida and to better estimate the percentage of plants that 

will be required to reach discharge limits more stringent than 3 mg/L TN and 0.1 mg/L TP. 

Urban Stormwater 

For the urban stormwater sector, the costs of complying with the NNC rule in those 

watersheds determined by EPA to be incrementally impaired are expected to be higher 

than EPA estimates. However, high uncertainty is prevalent throughout all aspects of this 

sector analysis. Published studies indicate that most traditional Florida urban BMPs will not be 

sufficient to comply with the numeric nutrient criteria. Furthermore, the per-acre costs of such 

BMPs are highly variable. EPA estimates of the affected land area are highly dependent on 

unverified existing BMP performance and compliance with urban stormwater rules. To improve 

the analysis, higher-efficiency BMPs should be considered, which have higher costs than 

traditional BMPs. The costs of retrofitting BMPs on developed land should also be considered.

Agriculture 

For the agricultural sector, the costs of complying with the NNC rule in those 

watersheds determined by EPA to be incrementally impaired are likely to be higher than 

EPA estimates. The incremental land area needing treatment was likely underestimated, 

individual costs for the BMPs assumed to be sufficient were underestimated, and the more 

effective and costly BMPs and regional treatment systems likely required to meet numeric 

nutrient criteria were not included in the analysis. The need for more stringent BMPs and 

treatment systems has been demonstrated in many of the Basin Management Action Plans 

(BMAPs) developed for impaired waters in Florida. Other critical omissions that could lead to 

increased costs include the degree of actual BMP program participation by agricultural producers 

and the costs of maintaining BMPs over time. 

Septic Systems 

For septic systems, the costs of complying with the NNC rule in those waterbodies 

determined by EPA to be incrementally impaired are likely to be substantially higher than 

EPA estimates. The exclusion of septic systems in springsheds is a significant deficiency of 
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EPA’s analysis. EPA received cost estimates from vendors of equipment capable of meeting a 

TN of 20 mg/L and TP of 10 mg/L, values which are much higher than EPA’s numeric nutrient 

criteria. Efforts should be made to consider septic systems in springsheds and a wider range of 

treatment systems including permeable reactive barriers, which are known to be more effective 

in removing nutrients to levels consistent with the numeric nutrient criteria. 

Government Costs 

The incremental costs for the government sector are expected to be higher than 

EPA estimates. Unit costs were based on low-end estimates of costs from a 2001 study that 

focused on a broad range of TMDL work not specifically related to either Florida TMDL 

development or nutrient TMDL development. Efforts should be made to quantify costs for 

Florida-specific and/or nutrient-specific TMDLs to provide more accurate unit costs for TMDL 

development. Additional government costs should also be considered, including costs for 

developing or approving SSACs and variances, costs associated with downstream protective 

values effectively reducing upstream criteria, and consideration of additional waters becoming 

impaired in the future. 

A FRAMEWORK FOR INCREMENTAL COST ANALYSIS OF A RULE CHANGE 

In Chapter 2, the Committee accepted the EPA definition of the incremental effect of a 

rule change and provided a critique of the methods by which the incremental costs were 

estimated. Chapter 3, in contrast, proposes an alternative framework for cost analysis. In 

accordance with what is required in EPA guidelines for preparing economic analyses, the chapter 

first provides a comprehensive analysis of the differences between the narrative and numeric 

nutrient criteria rules, organized by five broad stages of water quality management. Indeed, 

discrepancies in the cost estimates of EPA and other analysts can be traced to different 

assumptions about how the rules would affect actions taken in each of those five stages. That 

discussion is followed by presentation of the alternative framework for predicting the 

incremental costs of the various rules. Use of the framework can highlight differences in 

assumptions, help to narrow differences in the cost estimates if similar assumptions can be 

agreed upon, and highlight how uncertainties can be reduced analytically or by clarification of 

ambiguities in the rules. 

Comparing the Narrative and Numeric Nutrient Criteria Rules 

For the purposes of comparison, water quality management was divided into five stages: 

(1) listing waters as impaired, (2) establishing the stressor as nutrients, (3) defining the level of 

nutrient load reduction and calculating the TMDL, (4) TMDL/BMAP implementation, and (5) 

the determination of use attainment. Table 3-1 summarizes the differences in how these five 

stages occur under the narrative rule (which is considered the baseline), under the EPA’s NNC 
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rule that was the motivation for this report, and, for completeness, under the recently proposed 

Florida rule. The following broad findings regarding these differences are made: 

 Administrative costs for listing and TMDL development will be lower under the NNC 

rule than under the narrative or proposed Florida rules because there would be no 

biological assessment. 

 Compared to the narrative and proposed Florida rules, under the NNC rule the pace of 

listing and the number of waters listed will increase, but the rate at which TMDLs and 

BMAPs are developed and implemented will not necessarily increase. 

 Municipal and industrial wastewater dischargers may face substantial near-term increases 

in cost under the NNC rule. 

 Over time, there is significant uncertainty in nonpoint source load control costs under all 

three rules because of uncertainty about the incremental increase in the number of listed 

waters, about the nutrient target levels for N or P, and about cost and effectiveness of 

nonpoint source load control actions. 

How the Alternative Cost Analysis Works 

A more comprehensive cost analysis requires comparing the future time paths of costs at 

each stage of water quality management under either the NNC rule or proposed Florida rule vs. 

the narrative rule (the baseline). The analysis would be comprised of several tasks: 

Task 1 is to predict the decisions that would be made in each stage, for each rule. The 

predictions would be for specified time intervals, such as for five-year increments. The 

differences among the rules can lead to different decisions at each stage of water quality 

management, such as which waters are impaired. Prediction of these decisions requires making 

assumptions about both the likelihood of any particular decision and the relationship of that 

decision to others that follow in sequence. 

Task 2 is to estimate the administrative and load control costs under each rule and for 

each future time period. Chapter 2 provides a detailed review of the EPA estimate of unit costs 

and lengthy discussion of the effectiveness of the load control methods. In the broader 

framework, there should also be at least a narrative statement of the predicted water quality 

outcomes at each point in time. 

Task 3 is to characterize the uncertainties in Tasks 1 and 2 to determine if the costs of 

uncertainty are likely to be high. If so, formal probability analysis or scenario analysis should be 

conducted. Scenario analysis requires describing different combinations of uncertain future 

conditions that taken together can create different outcomes. Building scenarios can be a group 

activity that facilitates knowledge exchange and mutual understanding of central issues 

important to the results of the analysis. 

Task 4 is to calculate the incremental difference in total costs (costs of proposed rule 

minus the costs of narrative rule) and relate this to the incremental differences in water quality 

outcomes at each time period. 
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All of the metrics mentioned above can be recorded in a decision-making template (such 

as Figure 3-1). The template can be used, for example, to describe when and how many 

waterbodies would be listed over a fixed time period, some metric of stressor evaluation, the 

number of TMDL plans developed, some metric of plan implementation, and the number of 

waterbodies meeting the designated use. The basis of the metrics should be explained (i.e., 

derived from trend analysis of historical records, predictive models, statistical equations, expert 

judgment) and should be based on how the rule governs these stages and the available funding. 

Costs are calculated by multiplying the load reduction effort by the cost per unit of effort and are 

also recorded in the template. Once complete, the template will reveal the total cost difference of 

a rule change, which could be compared to the incremental differences in water quality outcomes 

and interpreted in light of the uncertainty of the cost estimates. This can be done for each time 

period and would provide information important to formulating annual public budgets and 

forecasting when water quality results might be realized. 

Findings about the Alternative Cost Analysis 

The incremental costs of the NNC rule are attributable to more than an increase in 

waterbodies listed and a requirement that all NPDES-permitted municipal and industrial sources 

discharging to surface water have certain effluent concentration limits. In computing the 

incremental effect, the appropriate baseline should have been defined as what would have 

occurred over time under the existing (narrative) rule. Thus, an incremental cost is the difference 

in implementation costs between two (or more) alternative future implementation time paths. 

Future cost analyses of rule changes would more fully represent areas of possible 

costs differences if they were more explicit in describing the differences between the rules 

over time. Administrative, load control, and water quality opportunity costs could be analyzed 

and reported as a cash flow over time, showing what sectors bear the costs as nutrient load 

reductions at different levels are pursued. Comparing the rules over time also can provide an 

opportunity to present a realistic picture of how the timing of water quality improvement actions 

might unfold with alternative rules, by illustrating the time lags between listing and achievement 

of water quality standards. Most importantly, reporting on timing would provide useful 

information for predicting annual budgetary requirements. 

Uncertainty is pervasive in estimating the incremental cost of implementing the 

NNC rule and is inadequately represented in the EPA analysis. In future analyses, reporting 

the difference in the time paths for implementation of water quality management rules, and 

associated uncertainties, would provide a more transparent and realistic way to compare costs of 

the different rules and provide more useful information about where, when, and how costs 

diverge. 

Some Florida stakeholders viewed the EPA cost analysis as being superficial or of 

limited scope, leading to reduced credibility. The result was to foster disagreement about 

embedded assumptions rather than using the analysis to isolate and possibly reconcile sources of 

disagreement. Cost analysis as outlined above can help convey cost estimates in a more 
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transparent way and thus facilitate learning, reduce misunderstandings among stakeholders, and 

increase public confidence in the results.

Conducting an alternative cost analysis, with increased attention to careful 

assessment of rule differences, stakeholder engagement, and uncertainty analysis, might 

not have been possible with the budget and time EPA spent on it cost analysis. Any critique 

of the existing EPA cost analysis should recognize that some deficiencies may be traced to time 

and budget limitations. 
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Chapter 1 

Introduction 

Nutrients such as nitrogen and phosphorus have long been known to cause degradation of 

surface waters when supplied at rates above the assimilative capacity of the waterbody. Excess 

nutrient loading leads to the proliferation of algae, which are in turn degraded by bacteria that 

can deplete waters of their dissolved oxygen. Nutrient enriched waters exhibit a variety of 

ecological symptoms, from harmful algal blooms to loss of submersed aquatic vegetation to fish 

kills. Waterbodies suffering from nutrient enrichment are evident in every region of the United 

States, from lakes and streams in the Midwest, to the Chesapeake Bay estuary, to coastal waters 

of the Gulf of Mexico. Although there can be considerable debate about the relative sources of 

nutrients in any given location, nutrients are widely known to stem from agricultural operations, 

urban landscapes, municipal and some industrial wastewater, mining activities, and atmospheric 

deposition. 

For decades Florida has experienced its share of nutrient related pollution issues, 

highlighted by pollution in Lake Okeechobee and the Everglades stemming principally from 

agriculture. Not surprisingly given its warm climate, topography, intense and varied agriculture, 

and rapid urbanization, hundreds of freshwater lakes and streams in Florida are polluted by 

nutrients to such an extent that natural populations of flora and fauna are out of balance. Florida 

has managed these waters using a narrative standard for nutrients. At the urging of the U.S. 

Environmental Protection Agency (EPA), states are moving toward the use of numeric water 

quality criteria for nutrients in an attempt to accelerate and standardize the restoration of 

nutrient-impaired waters. This report was written by a committee of the National Research 

Council charged with reviewing the economic implications of new numeric nutrient criteria 

developed by EPA for Florida’s inland waters. In particular, the Committee was asked to 

evaluate EPA’s method for estimating the incremental costs of implementing numeric criteria 

compared to the existing narrative standard. The issue has focused national attention on Florida, 

which is often the case in matters of water resources. 

TECHNICAL CHALLENGES OF NUTRIENT MANAGEMENT IN FLORIDA 

Florida has more than 11,000 miles of rivers and streams, over 7,700 lakes, and 27 firstmagnitude springs (stateofflorida.com; see Figure 1-1 for the state’s major water features). 

Many of these waterbodies suffer from nutrient pollution due to a unique convergence of human 

and environmental conditions. These include high population growth rates and resulting 

demands for water, land use changes from wetlands and forests to agriculture and urban areas, a 

tropical climate and flat topography, predominantly sandy soils and transmissive geologic 
Introduction 11

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FIGURE 1-1 Major Florida lakes, rivers, and springs. 

SOURCE: USGS National Hydrography Dataset 2011. http://nhd.usgs.gov/

materials, buildup of legacy nutrients, and competing value systems that influence perceptions of 

costs and risks of water quality impairment by Florida’s diverse population. Combined with the 

fact that treatment technologies to restore nutrient-impaired waters can be very expensive, these 

issues have made and will continue to make nutrient management in Florida an important but 

formidable and costly challenge, regardless of the regulatory paradigm used.

Population Growth 

Florida’s population increased from 12.9 million people in 1990 to 18.8 million in 2010 

(BEBR, 2010). In the next 20 years, Florida’s population is expected to increase 15 to 35 

percent (Figure 1-2), or to between 21.8 and 26.0 million people (BEBR, 2010). Population 

growth has the potential to affect transport of nitrogen and phosphorus from urban and suburban 

areas to surface waterbodies through increased discharge of stormwater and wastewater and loss 

of natural assimilative capacity. 
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FIGURE 1-2 Projected changes in Florida population between 2010 and 2030 for moderate growth 

scenario. 

SOURCE: BEBR (2010). 

Land Use Change

As Florida’s population increases, there will be secondary changes in land use (Figure 1-

3) and land management practices that will affect water quality. Expansion of urban and 

suburban land uses into former agricultural land will cause shifts in agricultural production, 

primarily in citrus, vegetable, row crop, and cow/calf operations. Expansion of urban and 

suburban areas into forested landscapes will replace perennial vegetation on relatively permeable 

soils with urban landscapes that have more impervious surface area, potentially increasing 

nutrient exports. The specific impacts of these secondary changes are difficult to assess, as they 

depend specifically on which landscapes are affected and the connectivity between these 

landscapes and nearby surface waterbodies. Nonetheless, one can expect that nutrient loads to 

surface waters will increase as forested areas are converted to urban and suburban land (USGS, 

1998). As agricultural lands are converted to urban and suburban land, a decrease in nutrient 

loads can be expected, although the exact direction and magnitude of the impact depends on 

many factors, including the type of agriculture practiced before conversion and the nature of the 

urban land use (e.g., industrial, low density residential, high density residential, park or golf 

course).
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FIGURE 1-3 FDEP compiled Florida land cover data for 2004. 

Climate and Topography 

The effects of excess nutrients applied to the land surface, whether in agricultural or 

urban activities, are exacerbated by the climatic and topographic conditions particular to Florida. 

High temperatures prevail throughout a significant fraction of the year, oscillating from 61 o

F to 

well over 95 o

F, and can be a powerful driver for the growth of aquatic vegetation. Florida 

annually receives significant amounts of precipitation throughout the state, ranging from nearly 

40 to over 60 inches (see Figure 1-4). Half of this precipitation occurs in a relatively short 

period from June to September in the form of highly localized intense thunderstorms as well as 

tropical storms, although there is variation in this seasonal distribution from north to south. 

Intense rainfall can produce heavy runoff (and associated pollutant loads) over short periods of 

time. Also, precipitation is a significant source of infiltration and groundwater recharge, which 

can carry excess nutrients to Florida’s lakes, springs, and rivers. 
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FIGURE 1-4 Annual Rainfall Distribution in Florida. Legend units are in inches. 

SOURCE: ERD (2007). 

Florida has relatively low-lying, flat topography (Figure 1-5), with a mean elevation of 

100 feet. Heavy rainfall and a shallow water table are responsible for large areas of the state 

being covered historically by shallow swamps, wetlands, and marshes. In order to use the land 

for agriculture, many of these areas have been hydrologically altered such that excess nutrients 

are transported to surface waters through tile drains or drainage ditches and are no longer stored 

or processed in-situ. Thus, water quality management strategies in Florida often take on the 

challenging and expensive task of restoring drained swamps, wetlands, and marshes to regain 

their nutrient assimilation capabilities.
Introduction 15

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FIGURE 1-5 Florida elevation patterns. 

SOURCE: USGS Digital Elevation Map Resources. http://data.geocomm.com/dem/demdownload.html 

Soil and Geology 

Florida water quality is strongly affected by natural variability in soil and geologic 

materials, as manifested in clear differences in lake physical, chemical, and biological 

characteristics across Florida’s 47 Lake Ecoregions (Griffith et al., 1997). Florida’s geology has 

been influenced by fluctuations in sea level. Because low-lying Florida was covered by oceans 

for millions of years, bedrock is composed mainly of carbonate rocks overlain by beach or dune 

sand. There are extensive localized deposits of phosphate rock that formed in ancient coral reefs. 

Lakes and rivers in these areas typically have elevated natural background levels of total 

phosphorus. Carbonate rocks have weathered to produce karst landscapes with many sinkholes 

and springs across wide regions of Florida. The majority of Florida lakes were formed in basins 

affected by dissolution of carbonate rock (Schiffer, 1998). Most of the inflow to these lakes 

arises from groundwater discharge rather than surface runoff. 

Soils in Florida are primarily spodosols or entisols, with a smaller portion being histosols 

and ultisols (Collins, 1985). Spodosols are coarse textured soils with an amorphous mixture of 

organic matter and aluminum, underlain by a gray eluvial (leached) layer where water has 

removed most of the organic matter. These soils are often used for production of citrus, and in 
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the wet season are artificially drained to lower the water table. Entisols are poorly developed 

sandy soils without horizons. They have rapid infiltration and are often irrigated. Both soil and 

geologic conditions can produce high background levels of nutrients in Florida waterbodies that 

make meeting numeric water quality criteria a challenge (as discussed in a subsequent section). 

Legacy Nutrients 

Legacy nutrients, primarily stemming from agriculture, exist in large quantities in many 

Florida soils, wetlands, lakes, streams, and aquifers. These legacy nutrients are the result of 

many decades of phosphorus transport from upland contributing areas in the case of lakes and 

wetlands, or many decades of nitrate leaching to aquifers, which has resulted in a significant 

impact on spring water quality. Legacy nutrient flows can dominate a watershed’s nutrient flows 

decades after nutrient additions have been curtailed. For example, Reddy et al. (2010) estimated 

total phosphorus (TP) storage in upland and wetland soils in the Lake Okeechobee basin to be 

215,000 metric tons. Approximately 80 percent of the stored phosphorus (or 169,800 metric 

tons) was estimated to be located in soils and stream sediments, with the remainder stored in lake 

sediments in the Upper Chain of Lakes, Lake Istokpoga, and Lake Okeechobee. Reddy et al. 

(2010) evaluated the potential long-term role of this legacy phosphorus on loading to Lake 

Okeechobee. Based on conservative estimates of phosphorus leaching rates and the amount of 

stored reactive phosphorus in the watershed, the authors predicted that legacy phosphorus could 

maintain a phosphorus load to Lake Okeechobee of 500 metric tons per year for the next 22 to 55 

years. This loading rate considers only legacy phosphorus stored in the soils and sediments and 

does not take into account new phosphorus additions in the basin. 

Internal nutrient loads from sediments in Lake Okeechobee to the water column are also 

significant. Based on several earlier research reports, Reddy et al. (2010) estimated the internal 

flux from mud sediments to the water column to be 112 metric tons of phosphorus per year 

continuing for 12 to 31 years. 

Waterbodies suffering from legacy nutrients generally require very stringent and costly 

BMPs in order to meet water quality goals similar to the numeric nutrient criteria. Examples of 

this situation, highlighting the more expensive actions required, are presented in Box 2-1 for 

Lake Okeechobee and for the Everglades Agricultural Area. 

IMPAIRMENT OF FLORIDA’S INLAND STREAMS, LAKES, AND SPRINGS 

Given the conditions described above, it is not surprising that impairment of Florida 

waters caused by nutrient overenrichment is widespread and mostly growing. Determinations of 

waterbody impairment for each State are required by the Clean Water Act Section 305b every 

two years. For the Florida 2008 305b report, there were sufficient data to evaluate (by area or 

length) 53 percent of the state’s rivers and streams and 81 percent of its lakes (FDEP, 2008); 

poor water quality (for all causes except mercury) was found in 28 percent of the river and 

stream miles and 25 percent of the lake acres. Approximately 2,565 total maximum daily load 

(TMDL) calculations will be required for 1,688 Florida waters. The 2008 report revealed that 

nutrients are the most prevalent pollutant in lakes, accounting for 349,248 impaired lake acres 

(157 lakes). For rivers and streams, nutrients are preceded by dissolved oxygen deficits (which 
Introduction 17

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can be driven by nutrients), mercury, and fecal coliform bacteria as major pollutants. At least 

128 rivers and streams, accounting for 1,049 stream miles, violate the narrative nutrient standard. 

Median phosphorus in monitored Florida waters is around 0.05 mg/L, after having risen steadily 

in the 20th century until the mid-1980s when the state adopted its Stormwater Rule (FDEP, 

2011). Water quality in many springs has also declined steadily since the 1970s. Thirty six (36) 

springs that have been monitored over the last 30 years have had increasing levels of nitrate-N, 

such that the combined median value has doubled (and ranges from 1 to 5 mg/L). 

Regarding the number of waterbodies requiring a TMDL because of nutrients, EPA 

(2010) states that there are approximately 168 waterbodies (denoted WBIDs1 in Florida) covered 

under nutrient TMDLs in Florida, 117 of which are for lakes and flowing waters. An accounting 

of those waterbodies in the EPA report reveals 89 TMDLs because most TMDLs cover more 

than one WBID (see Exhibit 2-8 in EPA, 2010). Another 497 waterbodies in Florida are listed as 

impaired and await nutrient TMDL development (EPA, 2010, Exhibit 2-7). Higher values are 

reported by the Florida Department of Environmental Protection (FDEP). FDEP considers 720 

WBIDs as impaired and in need of a TMDL; most have been listed as impaired based on a 

nutrient assessment, but others are impaired based on violations of the dissolved oxygen standard 

(personal communication, Frank Nearhoof, FDEP, 2011). There are 122 WBIDs for which a 

TMDL has already been developed (personal communication, Frank Nearhoof, FDEP, 2011). 

 As shown in Figure 1-6, the state has adopted nine Basin Management Action Plans 

(BMAPs) to implement dozens of TMDLs across the state (not just for nutrient-impaired waters). 

This process requires that pollutant loads be allocated among various sectors, including point 

sources like industrial and wastewater treatment plants, as well as more diffuse sources such as 

agriculture, stormwater from urban areas, and septic systems. The contributions of nitrogen and 

phosphorus vary substantially by sector and by basin; examples are given in Figures 1-7 and 1-8 

of nutrient loadings to the Wekiva River and the lower St. Johns River. Furthermore, each 

polluting sector operates under different legal and regulatory requirements, as described in 

greater detail in Chapter 2. 

 

1

 WBID refers to a Water Body Identification Number, but it includes more than just a waterbody. For a multitude 

of water resource purposes, Florida was divided up into polygons that roughly delineate the drainage basins 

surrounding individual waterbody assessment units, and each polygon was assigned a unique Water Body 

Identification Number. The assessment units are lakes or portions of lakes, springs, rivers and streams, segments of 

rivers and streams, and coastal, bay and estuarine waters in Florida. Thus, each WBID contains both water and the 

surrounding drainage basin. Note that many FDEP documents use the term WBID when discussing impaired 

waters; this use of the term should not be confused to mean that a WBID is only the waterbody. 
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FIGURE 1-6 TMDL Project implementation via Basins Management Action Plans. 

SOURCE: Florida Department of Environmental Protection (2011). 
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FIGURE 1-7 Relative Contribution of the Nitrogen Load by Sector to the Wekiva River in the middle St. 

Johns basin. OSTDS = on-site sewage treatment and disposal system (septic system). Legacy nutrients 

were not specified in this analysis. 

SOURCE: MACTEC (2010).

 FIGURE 1-8 Relative Contribution of the Nitrogen Load and Phosphorus Load by Sector to the Lower St. 

Johns River. Legacy nutrients were not specified in this analysis. 

SOURCE: Hendrickson et al. (2002).

 

Natural

Nonpoint

34%

Agricultur

al

Nonpoint

8%

Urban

Nonpoint

13% Other

Nonpoint

0%

Point

Source

45%

Lower St Johns River Total N Loads

(Estimated 1995‐1999 ave)

Natural

Nonpoint

14%

Agricultur

al

Nonpoint

12%

Urban

Nonpoint

17%

Other

Nonpoint

0%

Point

Source

57%

Lower St Johns River Total P Loads

(Estimated 1995‐1999 ave)
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WATER QUALITY STANDARDS AND THE TMDL PROCESS 

The Clean Water Act (CWA) addresses the protection and restoration of the nation’s 

waters through four major programs—water quality standards, point source permitting of 

wastewater dischargers via the national pollutant discharge elimination system (NPDES), total 

maximum daily loads (TMDLs), and the implementation of best management practices to control 

nonpoint sources of pollution. In their water quality standards, States establish the objectives for 

how waters are used (i.e., designated beneficial uses), along with the chemical, physical, and 

biological qualities of those same waters that would protect their designated uses. Designated 

uses include aquatic life support, recreation, drinking water supply, etc. The chemical, physical, 

and biological qualities of waters are collectively referred to as criteria. The criteria can be 

narrative, i.e., a description of the desired condition, or they can be specific numeric values. The 

CWA specifies that individual states set their own water quality standards, with those standards 

subject to approval by EPA. EPA can promulgate water quality standards for states if EPA 

determines that state standards are insufficient to meet the requirements of the CWA. 

When waterbodies fail to meet their standards, the TMDL program is implemented, the 

objective of which is attainment of water quality criteria by controlling both NPDES-permitted 

point sources and nonpoint sources of pollution. Nonpoint sources primarily consist of 

agricultural runoff, unregulated urban runoff, and atmospheric deposition of pollutants. A 

TMDL establishes the total pollutant load for both point and nonpoint sources. Load reductions 

for point sources are referred to as waste load allocations (WLA) while load reductions for 

nonpoint sources are referred to as load allocations (LA). Due to the uncertainty in the response 

of the waterbody to loading reductions, a margin of safety (MOS) is also included in the TMDL 

calculation. The pollutant load reduction required to meet the TMDL is the difference between 

the existing watershed loads and the loads specified by the TMDL. 

Load reductions for point and nonpoint sources are spelled out in TMDL implementation 

plans. In Florida, the Department of Environmental Protection develops comprehensive TMDL 

implementation strategies through BMAPs. BMAPs define permit limits for wastewater 

facilities to address the WLA portion of the TMDL as well as identifying urban, suburban, and 

agricultural best management practices and regional treatment systems required to meet the LA 

established by the TMDL. BMAPs are developed in conjunction with local stakeholders and 

seek to equitably allocate load reductions necessary to meet the TMDL. BMAPs rely on local 

involvement for successful implementation and once developed are adopted as enforceable 

documents by the FDEP Secretary. 

Because the CWA authorizes states to develop and implement water quality programs, 

each state implements those authorities subject to its own state laws and regulations. In general, 

however, Figure 1-9 provides a simplified diagram illustrating the general interaction of water 

quality standards, NPDES permitting, and TMDLs applicable to all states. Box 1-1 contains 

definitions of important water quality management terms. 
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State Places Impaired Waters on

the Impaired Waters (303d) List

State Develops Water Quality

Standards (WQS)

State Develops Wastewater

(NPDES) Permits Based on

Approved WQS

State Develops Total Maximum

Daily Load for Impaired Waters

State Monitors and Assesses

Waters for Compliance w/WQS

EPA Approves/Disapproves State’s

303d List

EPA Approves/Disapproves State’s

Total Maximum Daily Load

State Develops Implementation

Plan for Total Maximum Daily

Load

EPA Approves/Disapproves State’s

WQS

FIGURE 1-9 General Overview of the Clean Water Act WQS and TMDL Process.
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Box 1-1 Definitions of Selected Water Quality Management Terms 

1. Water Quality Standards—State or Federal regulatory requirements for surface and ground waters falling 

under the jurisdiction of the Clean Water Act. The standards consist of three parts - a designated use or 

uses, water quality criteria based upon on designated uses, and an antidegradation policy. 

2. Criteria—Elements of State water quality standards, expressed as constituent concentrations, levels, or 

narrative statements, representing a quality of water that supports a particular designated use. 

3. Designated Uses—Elements of State water quality standards that specify the uses for each water body 

whether or not a specific use is currently being attained. Mandatory Clean Water Act uses include aquatic 

life and recreation support. Other common uses are drinking water, irrigation, and industrial water supply 

support. 

4. Numeric Nutrient Criteria—Criteria that define the maximum nitrogen and/or phosphorus concentration in a 

water body that will maintain its designated use. 

5. Narrative Criteria—Narrative statements that define a desired condition of a water. For nutrients, in Florida 

the narrative criterion has been “no imbalance of flora or fauna" which can be determined by measuring 

biota, changes in dissolved oxygen, changes in pH, or other indicators related to nutrient pollution. 

6. Biological Criteria or Biocriteria—Numeric values or narrative expressions of the desired biological 

condition of aquatic communities in a waterbody. 

7. Independent Applicability—A concept put forth in EPA policy that states an exceedance of either chemical 

or biological water quality criteria provides irrefutable evidence of nonattainment of water quality standards 

regardless of the results of other types of assessments. 

8. Target—Generally, a non-regulatory narrative or numeric goal established to achieve or maintain a water’s 

designated uses. 

9. Nutrient Threshold—A concentration of nutrients against which ambient nutrient concentrations are 

compared to assess impairment of a water’s designated uses. In Florida’s proposed rules, nutrient 

thresholds only apply to streams. 

10. Water Body Identification Number (WBID)—Florida was divided up into polygons that roughly delineate the 

drainage basins surrounding individual waterbody assessment units, and each polygon was assigned a 

unique Water Body Identification Number. The assessment units are lakes or portions of lakes, springs, 

rivers and streams, segments of rivers and streams, and coastal, bay, and estuarine waters in Florida. 

Thus, each WBID contains both water and the surrounding drainage basin. Note that many FDEP 

documents use the term WBID when discussing impaired waters; this use of the term should not be 

misinterpreted to mean that a WBID is only the waterbody. 

11. Total Maximum Daily Load (TMDL)—the maximum pollutant load that a waterbody can receive and not 

violate its water quality standard. The TMDL also specifies how the load will be allocated among point and 

nonpoint source dischargers to that waterbody.

12. Basin Management Action Plan (BMAP)—A plan that outlines how a TMDL will be implemented. BMAPs 

can include revised permit limits for point sources as well as new pollutant control requirements for 

nonpoint sources. 

13. Site-Specific Alternative Criteria (SSAC)—If the characteristics of a receiving water allow attainment of 

designated uses with nutrient concentrations higher than EPA’s numeric nutrient criteria, site specific 

alternative criteria may be developed that could result in less stringent effluent limitations. Because 

dischargers may be required to obtain additional data to assess the appropriateness of SSAC, the extent to 

which dischargers use this mechanism to obtain regulatory relief is uncertain. 

 
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NUMERIC NUTRIENT CRITERIA IN FLORIDA 

Like most other states, Florida currently uses a narrative criterion to protect its waters 

from nutrient pollution, which states that “[in] no case shall nutrient concentrations of a body of 

water be altered so as to cause an imbalance in natural populations of aquatic flora and fauna.” 

Implementing this standard entails detailed biological assessments for individual waterbodies. 

Thus, this criterion has been implemented on a case-by-case and site-by-site basis for identifying 

and listing impaired waters, establishing TMDLs, and deriving appropriate NPDES permit limits 

for point sources. 

In 2009 EPA determined that numeric, rather than narrative, nutrient criteria would be 

necessary in Florida to meet the requirements of the CWA (EPA, 2009). This determination 

stemmed from a Consent Decree between EPA and several environmental organizations (the 

Florida Wildlife Federation, the Conservancy of Southwest Florida, the Environmental 

Confederation of Southwest Florida, St. John’s Riverkeeper, and the Sierra Club) that had sued 

EPA, maintaining that Florida’s narrative nutrient criteria were not protective of Florida’s 

waters. Their argument was that the narrative, site-by-site approach to address nutrient pollution 

problems in Florida was taking too much time and too many resources to allow the state to 

effectively and expeditiously address its thousands of stream miles and lake acres that violate the 

narrative nutrient standard. The environmental groups cited EPA’s 1998 National Strategy for 

the Development of Regional Nutrient Criteria calling for states to develop numeric nutrient 

criteria by 2003 as the rationale for requiring such criteria for Florida’s waters. Furthermore, 

they cited section 303 of the CWA, which requires EPA to “promptly prepare and publish” new 

or revised water quality standards “in any case where the Administrator determines that a revised 

or new standard is necessary to meet the requirements of this Act [the Clean Water Act].” 

The main fundamental difference between the narrative and numeric nutrient standards is 

that under the narrative standard waters are listed as impaired because of an imbalance of flora 

and fauna, which is based on biological condition assessment. Only subsequently are nutrients 

investigated as the cause of unacceptable biological conditions, and, if that determination is 

made, the state creates targets for N or P or both either in terms of allowable loads or 

concentrations. Under the numeric nutrient standard, simple chemical monitoring of a 

waterbody when compared to the numeric standards can lead to a water being listed as impaired, 

regardless of the associated biological condition of the water. (The reader is referred to the 

beginning of Chapter 3 for a more in-depth explanation of the differences between the narrative 

and numeric nutrient criteria.) The numeric nutrient standards established for Florida by EPA on 

November 14, 2010, are for nitrogen and phosphorus in lakes and flowing waters for different 

regions of the state, as shown in Table 1-1 (Federal Register, December 6, 2010, 75 FR 75762). 

This report does not evaluate the underlying scientific basis of the numeric nutrient 

criteria found in Table 1-1. Nonetheless, it is useful to consider the overall feasibility of meeting 

the given numeric nutrient criteria in Florida’s inland lakes under current conditions. As 

discussed in Box 1-2, a cursory analysis of lake data suggests that the numeric nutrient criteria 

will be difficult to attain in some (but not all) ecoregions due to differences in natural geology, 

soil, landscape, and hydrologic factors. Whether these results apply to streams as well is 

uncertain. Interestingly, a comparison of the numeric nutrient criteria with typical TMDL targets 

in impaired streams and lakes suggests that the numeric criteria are usually less stringent than the 

TMDL targets that have been developed under the narrative process, except for lakes with 

phosphorus pollution (see Box 3-1 in Chapter 3). 
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TABLE 1-1 Numeric Nutrient Criteria for Lakes and Flowing Waters in Florida 

Region/ 

Type of Water

Chlorophyll-a

(mg/L)

TN Criteria 

(mg/L)

TP Criteria 

(mg/L)

Nitrate + Nitrite 

Criteria (mg/L)

Colored Lakes1 0.020 1.27 0.050 NA 

Clear Lakes (high 

alkalinity)2 

0.020 1.05 0.031 NA 

Clear Lakes (low 

alkalinity)3 

0.006 0.50 0.011 NA 

Panhandle East 

Flowing Waters 

NA 1.03 0.18 NA 

Panhandle West 

Flowing Waters 

NA 0.67 0.06 NA 

North Central 

Flowing Waters 

NA 1.87 0.30 NA 

West Central 

Flowing Waters 

NA 1.65 0.49 NA 

Peninsula Flowing 

Waters 

NA 1.54 0.12 NA 

Springs NA NA NA 0.35 

NA = not applicable 

1Long-term Color > 40 Pt-Co 

2Long-term Color ≤ 40 Pt-Co and Alkalinity > 20 mg/L CaCO3

. 

3Long-term Color ≤ 40 Pt-Co and Alkalinity ≤ 20 mg/L CaCO3 

.

SOURCE: EPA (2010). 

It should be noted that Florida is still in the process of trying to develop its own numeric 

criteria for nutrients that would supersede Table 1-1 if approved by the Florida Environmental 

Regulatory Commission (which occurred December 8, 2011), the Florida legislature, and EPA. 

As of the writing of this report, FDEP has developed a hybrid criteria approach that includes 

aspects of both the current Florida narrative criteria and the EPA numeric criteria. The FDEP 

proposal would establish generally applicable numeric nutrient “thresholds” as an additional 

interpretation of the Florida narrative criteria for streams, but would only use the threshold 

values to make impairment decisions if there is concurrent confirmation of biological 

impairment. In addition, if a site-specific “numeric nutrient interpretation” exists, such as a sitespecific numeric criterion or an approved numeric TMDL target, the site-specific interpretation 

is used in lieu of the applicable numeric nutrient threshold. Compared to the EPA’s numeric 

nutrient criteria, this hybrid approach has more flexibility for dealing with natural background 

nutrient sources and variability in site-specific conditions at finer scales. 

The newly proposed FDEP criteria would also include a new antidegradation-type 

provision for assessing impairment. This provision would place waters on the State’s impaired 

waters planning list if they show an adverse or worsening trend in biological response variables 

or dissolved oxygen (DO)—even if waters did not fail any of the biological indicators. The 

listing of waters based on adverse nutrient response trends would provide FDEP the opportunity 

to proactively address worsening nutrient conditions prior to observing an actual impairment of 

waters’ designated uses. The incremental costs of implementing Florida’s hybrid criteria 

approach are being evaluated by Florida State University—an effort for which the results of this 

report should be useful. 
Introduction 25

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Box 1-2 

Challenges in Meeting the Numeric Nutrient Criteria in Lakes

The Committee conducted a cursory analysis of lake data (which incidentally were not used by 

EPA in its economic analysis) to determine what percentage of Florida lakes would likely violate the 

numeric nutrient criteria (NNC). Note that this analysis was approximate because the lake data did not 

necessarily use the same threshold values as the NNC. Nonetheless, the analysis suggests that it will be 

challenging to meet the NNC in many Florida lakes. 

Florida has over 7,700 lakes (Griffith et al., 1997). The aquatic ecoregion framework developed 

nationally by Omernik (1987) has proven useful for lake water quality assessment and management in 

Minnesota (Heiskary and Walker, 1988; Hatch et al., 2001; Birr and Mulla, 2002) and Ohio (Fulmer and 

Cooke, 1990). Griffith et al. (1997) divided Florida into 47 level IV aquatic ecoregions to describe regional 

variations in Florida lake water quality characteristics. For each ecoregion, lake water quality 

characteristics were summarized. 

For colored lakes the numeric nutrient criteria proposed by EPA (2010) are 0.050 mg/L TP and 

1.27 mg/L TN. Using data compiled by Griffith et al. (1997) these standards can be met by most lakes in 

ten of thirteen of Florida’s level IV aquatic ecoregions having colored lakes. The greatest difficulty will be 

in the Southwestern Flatlands ecoregion, where 75% of the lakes exceed 0.075 mg/L TP and 1.25 mg/L 

TN. This is a coastal lowland region, with citrus, pasture and urban development. Numeric criteria will 

also be difficult to attain in the Northern Peninsula Karst Plains ecoregion, where 50% of the lakes exceed 

0.074 mg/L TP. There are widespread phosphatic sand deposits in this region. In the Central Valley 

ecoregion 50% of lakes exceed 1.4 mg/L TN, so the numeric criteria for TN will be widely violated. This is 

a region of large, shallow eutrophic lakes with nutrient enriched soils. 

For clear alkaline lakes the numeric nutrient criteria proposed by EPA are 0.031 mg/L TP and 

1.05 mg/L TN. There are eight level IV aquatic ecoregions with these types of lakes in Florida. Numeric 

criteria can likely be met in six of these ecoregions. The remaining ecoregions are characterized by 

extensive geologic deposits of phosphatic sands or clays, where attaining numeric nutrient criteria is 

probably difficult. In the Lakeland/Bone Valley ecoregion, for example, there is extensive mining for 

phosphate deposits. The vast majority of lakes in this ecoregion exceed 0.12 mg/L TP and 1.7 mg/L TN. 

In the Orlando Ridge ecoregion half of the lakes exceed 0.031 mg/L TP. 

For clear non-alkaline lakes the numeric nutrient criteria proposed by EPA are 0.011 mg/L TP and 

0.5 mg/L TN. There are thirteen Level IV aquatic ecoregions in Florida with these types of lakes. The 

numeric nutrient criteria can likely be met in six of these ecoregions. Attaining these criteria in the other 

seven ecoregions will be challenging, if feasible at all. For example, 75% of lakes in the North Brooksville 

Ridge ecoregion exceed 0.008 mg/L TP and 0.57 mg/L TN. This area is characterized by thick sands 

underlain by phosphatic deposits. In the Weeki Wachee Hills ecoregion, 75% of the lakes exceed 0.009 

mg/L TP and 0.63 mg/L TN. 

The results of this analysis suggest that meeting the NNC in lakes of Florida will be challenging, 

because TP concentrations in some lakes are controlled by natural geologic, soil and hydrologic factors 

(Bachmann et al., 2010) in addition to anthropogenic factors. It will be especially challenging to meet the 

NNC for TP in lakes within ecoregions where phosphatic deposits occur (e.g., North Peninsula Karst 

Plains, Lakeland/Bone Valley, and North Brooksville Ridge). It should be noted that FDEP rules allow for 

exceptions to meeting numeric standards given natural background conditions, using the site-specific 

alternative criteria (SSAC) process. 
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Estimates of the Incremental Cost to Implement the Numeric Nutrient Criteria 

EPA’s numeric nutrient criteria for Florida may result in new impaired waters listings 

and reevaluation of the TMDLs for the waters that are currently listed as impaired. These 

actions may lead to new or revised NPDES permit conditions for point source dischargers, 

and/or nutrient control requirements or best management practice (BMP) guidance on other 

pollutant sources, although the numeric nutrient criteria rule itself does not establish 

requirements directly applicable to such entities. Therefore, EPA was required to produce an 

economic analysis of the potential incremental costs and benefits that may be associated with 

implementation of the numeric nutrient criteria rule, taking into account existing federal and 

Florida regulations. 

EPA’s economic analysis (EPA, 2010) is an assessment of the potential incremental cost 

of implementing the numeric nutrient criteria, taking into account technologies and other 

controls that may be used to meet the criteria in waters newly identified as impaired as a result of 

the new criteria. The analysis assumes that affected parties will make use of various site-specific 

criteria adjustment processes and Florida’s ability to re-designate beneficial uses, grant 

variances, and establish load allocations in TMDLs. EPA’s stated annual combined incremental 

cost estimates range from $135.5 to $206.1 million per year, which is a total of $1.4 to $2.2 

billion over a 20-year period (EPA, 2010). 

Other stakeholder groups have produced their own estimates of the cost of implementing 

the numeric nutrient criteria, with some having estimated costs as high as to $12 billion (FDEP, 

2010). Like the EPA report, reports from FDEP (2010) and Cardno ENTRIX (2010a,b) on 

behalf of the Florida Water Quality Coalition cover all pollutant sectors. Other groups targeted 

specific portions of the EPA economic analysis, including reports from the Florida Water 

Environment Association Utility Council (municipal point sources; Carollo Engineers, 2010), the 

Florida Department of Agriculture and Consumer Services (agriculture; Budell et al., 2010), the 

Florida Pulp and Paper and the Florida Phosphate reports (industrial point sources; AWARE 

Environmental Inc. and AquAeTer Inc., 2010, and ENVIRON, 2010, respectively).

The discrepancies between the EPA and other analyses arise from many factors (as 

discussed in greater detail in Chapter 2). First, EPA considers only those additional waters that 

that are newly identified as impaired based on the numeric nutrient criteria and does not consider 

waters that Florida has already determined to be impaired based on existing FDEP assessment 

methodologies. Second, EPA and other stakeholders made different assumptions about which 

point and nonpoint source activities to include in their cost analyses. Third, there are differing 

opinions about the level of technology that will be needed and thus the cost necessary to meet the 

numeric criteria. The EPA economic analysis assumes that available regulatory exemptions will 

be sought, while other analyses assume that more expensive technologies will be required. The 

cost discrepancies between the EPA analysis and others are presented in Table 1-2. 

Part of the controversy in Florida has been that the media, the public, and also perhaps 

decision makers have been misinterpreting the EPA incremental cost estimate as the total cost 

needed to reduce nutrient loads to levels that would meet designated uses within impaired 

waterbodies. Indeed, several of the competing stakeholder analyses that approach the billion 

dollar annual level (see Table 1-2) are clearly a reflection of attempts to estimate the total cost, 

not the incremental cost. A second point of controversy is that EPA implicitly assumes that the 

implementation activities included in its cost analysis would be adequate to meet the numeric 

nutrient criteria in both the incrementally impaired waters and in those already be identified as 
Introduction 27

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TABLE 1-2 Cost Discrepancies between the EPA Economic Analysis and other reports. 

Nutrient Source Stakeholder 

Estimates

EPA (2010) Cardno ENTRIX 

(2011b)

Municipal WWTPs $2–4.6 billion/yr 

(Carollo, 2010)

$22.3–38.1 million/yr $41–395 million/yr

Industrial Facilities $2.1 billion/yr1

(FDEP, 2010) 

$25.4 million/yr $270–1,973 million/yr 

Urban Stormwater $2.0 billion/yr 

(FDEP, 2010) 

$60.5–108 million/yr $61–629 million/yr

Agriculture $0.9–1.6 billion/yr 

(Budell et al., 2010)

$19.9–23 million/yr $33–969 million/yr

Septic Systems $0.9–2.9 billion/yr 

(FDEP, 2010) 

$6.6–10.7 million/yr $8–65 million/yr

Government 

Expenditures 

 $0.9 million/yr $1–11 million/yr2

1

This does not include the costs determined by the Pulp and Paper Industry and the Phosphate Industry found in 

AWARE Environmental Inc. and AquAeTer Inc., 2010, and ENVIRON, 2010, respectively. 2

These numbers came from a spreadsheet Cardno ENTRIX made available at their ftp site. The range is the low end 

of their "BMP/LOT" analysis and the high end of their "End of Pipe" analysis. 

nutrient stressed under the narrative process. That is, the EPA cost analysis fails to acknowledge 

the possibility that what Florida historically required will be insufficient to achieve the numeric 

nutrient criteria. Chapter 2 makes it clear that what has been implemented in the past has made 

some water quality improvements in some sectors, but in general has not led to attainment of 

designated uses. 

This is not meant to suggest that the EPA analysis was wrong in focusing on the 

incremental costs; indeed, this was the most appropriate approach to take (although EPA was not 

comprehensive—see Chapter 3). Nonetheless, subsequent to EPA releasing its economic 

analysis a period of confusion ensued, during which stakeholders argued primarily about the total 

cost and confused incremental cost with total cost. It is certain that the total costs of attaining 

water quality standards in Florida waters impaired by nutrients will be enormous, not only 

because of ongoing polluting activities and the current state of water quality impairment in 

Florida but because of natural background sources of nutrients, legacy sources that are unlikely 

to be remediated by common nonpoint source BMPs, and ongoing changes in population, land 

use, and the economy. These total long-term costs of restoring impaired surface waterbodies are 

going to be much higher than either the incremental costs of the EPA’s numeric nutrient criteria 

or the historic costs already incurred for TMDLs and BMAPs in waters impaired under Florida’s 

narrative criteria, regardless of the future regulatory framework. If FDEP made a statement to 

that effect, it would further the public’s understanding of the scope of nutrient pollution in 

Florida and the challenges to its management, and overcome misunderstandings that have arisen 

during debate about EPA’s numeric nutrient criteria. 

REQUEST FOR NATIONAL RESEARCH COUNCIL STUDY 

Resolution of the discrepancies between various stakeholders described above is critical 

to moving forward with implementation of the numeric nutrient criteria. Thus, EPA requested 
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that the National Research Council (NRC) conduct a review of the Agency’s economic analysis 

of the incremental costs of state implementation of final numeric nutrient criteria for lakes and 

flowing waters in Florida. In response to this request, the NRC formed a committee to evaluate 

the cost estimates of implementing the numeric criteria, including the relevance and validity of 

certain assumptions and methodologies used in the economic analysis. The Committee’s 

statement of task is found in Box 1-3. 

There were a number of constraints placed on the Committee that were necessary in order 

for it to produce a report by the March 2012 deadline imposed by EPA. First, it should be noted 

that the Committee was not asked to do an assessment of the rule per se. This is important 

because the actual numeric values have been the source of considerable controversy in Florida 

for the last few years, and at one point the State of Florida requested the NRC’s involvement in 

determining what the numbers should be (although this request was never fully realized). For the 

purposes of this study, the numeric criteria in Table 1-1 were assumed to be unmovable. An 

EPA Science Advisory Board panel has issued a report evaluating the scientific merit of the 

proposed numeric standards (EPA, 2011). 

Second, the Committee was not asked to address the benefits of implementing the 

numeric nutrient criteria, despite the existence of a chapter in the EPA report devoted to a 

consideration of benefits and considerable interest from some stakeholders. Nor does the 

Committee address the important but indirect costs associated with implementing the numeric 

criteria, such as the number of jobs lost or gained, how certain related sectors of the economy 

will fare under the numeric criteria like real estate and tourism, etc. The committee considered 

all of these topics beyond the scope of the study given the statement of task and the very short 

time frame in which it was operating. 

Finally, the Committee was not asked to do its own cost estimate; i.e., there is no new 

calculation of the estimated costs of implementing the criteria in this report. Rather, the report 

focuses on the methods to be used in any future analyses, and it evaluates the validity of 

assumptions found in the EPA report and the reports of various stakeholders. 

The Committee made use of a wide variety of sources, most importantly the economic 

analyses produced by EPA and other stakeholder groups. The Committee held two open 

meetings, one in Orlando, Florida, in July 2011, and one in Washington, DC, in October 2011, to 

hear from these groups, including open-microphone sessions to take comments from the 

interested public at both meetings. The third committee meeting held in December 2011 was 

entirely in closed session. Additional background materials were also gathered from the Florida 

Department of Environmental Protection, the main agency responsible for water quality 

management in Florida, and from the EPA Office of Science and Technology. Given the 

detailed technical and regulatory nature of the subject, the primary audience for this report is 

EPA, FDEP, and the stakeholder groups mentioned above. 

 Chapter 2, which addresses the second and third items in the statement of task, 

comprehensively discusses the EPA’s and others’ assumptions and incremental cost estimates for 

five pollutant sectors, including municipal and industrial wastewater treatment plants, 

agriculture, urban stormwater, and septic systems. The incremental costs to government of 

implementing the NNC rule are also considered. Chapter 3 tackles the first item in the statement 

of task by providing an alternative framework for the cost analysis that could be used by EPA for 

future work in Florida and elsewhere. The conceptual framework provides an alternative way to 

(1) more accurately characterize baselines and consequently the incremental effect of the NNC 

Rule and (2) address the timing and uncertainty of costs of a proposed rule change. Taking into 
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Box 1-3 

NRC Committee Statement of Task 

In response to a request from the U.S. Environmental Protection Agency, this study undertaken 

by a special committee organized and overseen by the NRC’s Water Science and Technology Board is 

reviewing EPA’s analysis of the costs of state implementation of final numeric nutrient criteria for lakes 

and flowing waters in Florida. Because the numeric nutrient criteria rule is scheduled to take effect March 

6, 2012, the EPA needs input quickly on a number of important issues. The committee will evaluate the 

cost estimates of implementing the numeric criteria, including the relevance and validity of certain 

assumptions and methods used in the economic analysis. The evaluation will give special attention to 

those assumptions that may account for discrepancies between EPA’s analysis and those of several 

stakeholder groups. Specifically, the committee will review and comment on the implications of: 

1. EPA’s assumption that costs should only be determined for waters that will be “newly impaired” as a 

result of the numeric nutrient criteria. 

2. EPA’s decision to estimate the costs of only those sources of pollution that would directly affect a 

“newly impaired” water—in particular the number of wastewater treatment plants, the acreage of 

agricultural land, the acreage of urban areas, and the number of septic systems included in the EPA 

analysis. 

3. EPA’s assumptions about the levels of control that could be used by certain point and nonpoint 

sources, such as wastewater treatment plants, industrial point sources, agricultural activities, and septic 

systems. Examples of these assumptions could include a decision to seek a regulatory exemption, 

whether to implement reverse osmosis technology, or to use conventional best management practices 

rather than more expensive water treatment options. 

 

consideration the narrative process, the numeric nutrient criteria, and the proposed FDEP hybrid 

approach, the chapter highlights the importance of evaluating the key differences in the three 

processes and the resulting implications for overall cost, including the critical issue of timing. 

The findings and recommendations in this report should be useful regardless of whether the 

EPA’s NNC rule or the proposed FDEP rule is ultimately adopted. 

REFERENCES 

AWARE Environmental Inc. and AquAeTer Inc. 2010. Treatment Technologies Assessment 

for Removal of Nitrogen and Phosphorus in Pulp and Paper Wastewater. Prepared for 

the Florida Pulp and Paper Association. April 2010. 

Bachmann, R. W., M. V. Hoyer and D. E. Canfield, Jr. 2010. Draft alternative nutrient criteria 

for Florida lakes. Florida LAKEWATCH whitepaper. Univ. Florida. Gainesville, Fl. 

Birr, A. S., and D. J. Mulla. 2002. Relationship between lake and ground water quality patterns 

and Minnesota agroecoregions. Hydrological Sci. Tech. 18(1-4):31-41. 

Budell, R., et al., A. W. Hodges et al., and D. Bottcher. 2010. Economic Impacts and 

Compliance Costs of Proposed EPA Water Quality Standards for the State of Florida’s 

Lakes and Flowing Waters. April 27, 2010. 
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Bureau of Economic and Business Research (BEBR). 2010. Population studies. 

http://www.bebr.ufl.edu/ Univ. FL. Gainesville, FL. 

Cardno ENTRIX. 2011a. Economic Analysis of the Proposed Federal Numeric Nutrient 

Criteria for Florida. Prepared for the FL Water Quality Coalition by Cardno ENTRIX, 

June 2011. 

Cardno ENTRIX. 2011b. Addendum to the Economic Analysis of the Federal Numeric Nutrient 

Criteria for Florida. Prepared for the Florida Water Quality Coalition by Cardno 

ENTRIX, July, 2011. 

Carollo Engineers. 2010. Costs for Utilities and Their Ratepayers to Comply With EPA 

Numeric Nutrient Criteria for Freshwater Dischargers. Prepared for the Florida Water 

Environment Association Utility Council. November 2010. 

Collins, M. E. 1985. Key to Soil Orders in Florida. Gainesville, FL: University of Florida. 

ENVIRON. 2010. Assessment of Financial Impact on Phosphate Mining and Mineral 

Processing: Complying with EPA’s Proposed Nutrient Water Quality Standards for 

Florida. Prepared for the Florida Phosphate Industry. April 2010. 

Environmental Research & Design, Inc. 2007. Evaluation of Current Stormwater Design 

Criteria within the State of Florida. Final Report prepared for Florida Department of 

Environmental Protection, Orlando, FL. 

http://www.dep.state.fl.us/water/nonpoint/docs/nonpoint/SW_TreatmentReportFinal_719

07.pdf 

Florida Department of Environmental Protection (FDEP). 2008. Integrated Water Quality 

Assessment for Florida: 2008 305(b) Report and 303(d) List Update, October 2008. 

FDEP. 2010. Review of EPA’s “Preliminary Estimate of Potential Compliance Costs and 

Benefits Associated with EPA’s Proposed Numeric Nutrient Criteria for Florida.” April 

28, 2010. 

FDEP. 2011. An Overview of Nutrient Management in Florida, Working Draft – April 2011. 

Fulmer, D. G., and G. D. Cooke. 1990. Evaluating the restoration potential of 19 Ohio 

reservoirs. Lake Reserv. Manage. 6:197-206. 

Griffith, G. E., D. E. Canfield, Jr., C. A. Horsburgh, and J. M. Omernik. 1997. Lake regions of 

Florida. EPA/R-97/127. US EPA. NHREEL. Western Ecology Division. Corvallis, 

OR. 

Hatch, L. K., A. P. Mallawatantri, D. Wheeler, A. Gleason, D. J. Mulla, J. A. Perry, K. W. 

Easter, P. Brezonik, R. Smith, and L. Gerlach. 2001. Land management at the major 

watershed - agroecoregion intersection. J. Soil Water Conservation 56:44-51. 

Heiskary, S., and W. W. Walker, Jr. 1988. Developing phosphorus criteria for Minnesota lakes. 

Lake Reserv. Manage. 4:1-9. 

Hendrickson, J., N. Trahan, E. Stecker, and Y. Ouyang. 2002. Estimation and assessment of the 

current and historic external load of nitrogen, phosphorus and organic carbon to the 

Lower St. Johns River for the fulfillment of TMDL and PLRG objectives. Palatka, 

Florida: St. Johns River Water Management District, Department of Water Resources 

MACTEC. 2010. Final Report Wekiva River Basin Nitrate Sourcing Study. Prepared for the 

SJRWMD and FDEP. March 2010. 

Omernik, J. M. 1987. Ecoregions of the conterminous United States. Annals Assoc. Am. Geog. 

77:118-125. 
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Reddy, K. E., S. Newman, T. Z. Osborne, J. R. White, and C. Fitz. 2010. Legacy phosphorus in 

the Everglades ecosystem: Implications to management and restoration. Critical Reviews 

in Environmental Science Technology (in review). 

Schiffer, D. 1998. Hydrology of Central Florida lakes-A primer. U.S. Geological Survey 

circular 1137. Denver, CO. U.S. Govt. Printing Office. 

U.S. Environmental Protection Agency (EPA). 2009. Letter from Benjamin Grumbles, 

Assistant Administrator, Office of Water to Michael Sole, Secretary, Florida Department 

of Environmental Protection. January 14. 

http://www.epa.gov/waterscience/standards/rules/fl-determination20090114.pdf. 

U.S. EPA. 2010. Economic Analysis of Final Water Quality Standards for Nutrients in Lakes 

and Flowing Waters in Florida. Environmental Protection Agency; November, 2010. 

U.S. EPA. 2011. Methods and Approaches for Deriving Numeric Criteria for 

Nitrogen/Phosphorus Pollution in Florida’s Estuaries, Coastal Waters, and Southern 

Inland Flowing Waters. US EPA. Washington, DC. 

http://yosemite.epa.gov/sab/sabproduct.nsf/fedrgstr_activities/DCC3488B67473BDA852

578D20058F3C9/$File/EPA-SAB-11-010-unsigned.pdf. 

USGS. 1998. Water Quality in the Georgia-Florida Coastal Plain, Georgia and Florida, 1992-

96. By Marian P. Berndt, Hilda H. Hatzell, Christy A. Crandall, Michael Turtora, John 

R. Pittman, and Edward T. Oaksford. U. S. Geological Survey Circular 1151. 
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Chapter 2 

Assessment and Commentary on EPA’s Analysis 

 As indicated in Chapter 1, the intent of the U.S. Environmental Protection Agency’s 

(EPA) analysis was to assess the differential costs of nutrient load reduction under the numeric 

nutrient criteria (NNC) rule vs. Florida’s narrative rule. This chapter accepts the EPA definition 

of the incremental effect of the NNC rule and focuses on the way EPA estimated that effect and 

the costs for different sectors including municipal wastewater facilities, industrial facilities, 

agriculture lands, urban stormwater, and septic systems. The associated costs of governmental 

administration are also discussed. This chapter also includes some initial descriptions of the 

current regulatory requirements for each sector and how regulatory uncertainties can lead to 

different assumptions about the effect of the NNC rule on the level and timing of costs. Chapter 

3 provides an expanded discussion of the incremental effect of the rule and how uncertainty 

about the rule change can affect incremental costs. 

EPA COST ANALYSIS METHODS: OVERVIEW 

 The first part of EPA’s analysis was conducted for point sources, identifying the number 

of point sources that would have to improve treatment in response to the NNC rule, the likely 

technological upgrades that would be implemented, and the cost of upgrades based on unit costs 

multiplied by the actual flow rate of each point source. The next step in the EPA analysis was to 

determine the potential incrementally impaired waterbodies—that is, an estimate of those waters 

that may be expected to be in noncompliance with the numeric nutrient criteria, but that would 

not be impaired under the narrative rule. Once this set of waters was defined, the analysis 

proceeded to estimate the location and amount of land area that would require load controls to 

meet the numeric nutrient criteria in the waterbody. For the stormwater and agricultural sources, 

EPA identified the corresponding acreage draining to the potential incrementally impaired 

waterbodies, reduced the acreage considered based on best management programs that were 

already in place, selected a set of BMPs that EPA staff deemed adequate and cost-effective, and 

then applied a unit cost to the resulting acreage to estimate the total cost for the two sectors. For 

septic systems EPA determined the number of systems within 500 feet of a potential 

incrementally impaired waterbody and multiplied this number by unit cost to upgrade septic 

systems to reduce their nutrient loads. 

 Several key regulatory assumptions were made by EPA and are discussed in the 

subsequent sector analyses only if the Committee took issue with them. These assumptions 

include: 
Assessment and Commentary on EPA’s Analysis 33 

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 Impaired waterbodies where a total maximum daily load (TMDL) has already been 

developed based on the narrative criteria were not considered, assuming that the 

TMDLs would serve as the basis for site-specific alternative criteria (SSAC), if 

needed; 

 Waters that are currently listed as impaired based on the narrative criteria were also 

not considered, because it was assumed that a TMDL for nitrogen (N) and/or 

phosphorus (P) would be developed and that this TMDL would serve as the basis for 

an SSAC determination; 

 Municipal and industrial plants discharging at 3 mg/L for total nitrogen (TN) and 0.1 

mg/L for total phosphorus (TP) were considered “in compliance”; and 

 The cost of actions to reduce pollutant loads associated with implementation of the 

statewide Stormwater Rule, the Urban Turf Fertilizer Rule, the Florida Department of 

Environmental Protection (FDEP) Dairy Rule, and Concentrated Animal Feeding 

Operation (CAFO) Requirements would not necessarily be accruable to the NNC 

rule, since these programs are already in place. 

Three analytical assumptions of the EPA analysis were accepted for this chapter (and are 

returned to in Chapter 3): 

 The definition of the incremental effect of the NNC rule was defined and limited to 

(1) waters that would be newly listed and determined to be stressed by nutrients and 

(2) National Pollutant Discharge Elimination System (NPDES) municipal and 

industrial sources that would receive certain concentration limits in their discharge 

permits; 

 EPA assessed the incremental effect of the NNC rule at a single point in time, 

assuming no further changes would occur under the narrative process (which was the 

baseline), instead of comparing the future outcomes of both processes over time; and 

 The analysis assumed constant temporal conditions in such factors as population, land 

use, crop types, management practices, industrial activities, and climate were 

assumed, even though the analysis acknowledged that the effects would occur over 

time (for example, there was a 20-year horizon for amortizing capital costs). 

Determination of Incrementally Impaired Waters 

 EPA defined one incremental effect of the NNC rule as the number of waterbodies that 

would be listed as impaired under the numeric nutrient criteria but not under the narrative 

criteria. Had monitoring data for N and P concentrations been available for all waterbodies, this 

would be a simple exercise. However, out of a total of 3,765 freshwater stream segments in 

Florida, a very large fraction (84 to 89 percent) lacks sufficient monitoring data on N and P 

concentrations to make an assessment, based on the application of Florida’s Impaired Waters 

Rule (IWR) (FDEP, 2011). For the 1,444 lake segments in Florida, 59 to 78 percent lack 

sufficient information to be assessed (FDEP, 2011), which covers a substantial area of the state, 

particularly in the north and northwest (see Figure 2-1). Thus, of the 5,209 freshwater WBIDs in 

Florida (see Chapter 1 for the definition of a WBID), approximately 77 to 86 percent cannot 
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currently be assessed.1 Despite a long record of water quality monitoring in Florida, the vast 

majority of the waterbodies have insufficient information to determine whether action is needed. 

FIGURE 2-1 WBIDS with insufficient data to assess impairment. 

SOURCE: Karen Milam, EPA.

 

                                                           

1

 The range in unassessed segments reflects the difference in the amount of information required to assess under the 

current narrative criteria (one year of data) compared to the NNC (three years), as well as differences in the quality 

of the data that EPA and FDEP considered necessary to determine whether a WBID can be assessed. Furthermore, 

the sentence is not implying that 77 to 86 percent of Florida waters have no monitoring data, just that there is not 

enough data to make a determination of impairment based on the requirements of the IWR.
Assessment and Commentary on EPA’s Analysis 35 

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Streams and Lakes2

 Faced with this limitation, EPA opted for the following approach to estimate the number 

of incrementally impaired streams and lakes. Using the FDEP database of WBIDs and 

monitoring data for the past five years from IWR Run 40 (a subset of Florida’s water quality 

data), EPA first identified potentially impaired waterbodies by comparing their monitoring data 

to the numeric nutrient criteria. WBIDs where a nutrient-related TMDL had already been 

established were excluded, based on the assumption that FDEP would seek SSACs for those 

WBIDs and/or that “controls to reduce nutrients already required in the absence of EPA’s rule 

would be sufficient”. In addition, EPA identified WBIDs adjacent to lakes to which downstream 

protective values could apply3. Finally, all of the unassessed waters were excluded by EPA from 

consideration as potentially impaired due to the new rule by assuming that unassessed 

waterbodies are likely to be unimpaired, given Florida’s focus on monitoring the most polluted 

streams and lakes. In other words, EPA assumed that if a waterbody were likely to be impaired, 

Florida would have already known about it and monitored it under the existing program of 

narrative criteria. Using these assumptions, EPA determined that only 325 WBIDs potentially 

exceed the numeric nutrient criteria [see Exhibit ES-4 in EPA (2010)]. Given EPA’s 

assumptions, the Committee considers the EPA estimate to be a lower bound on the number of 

incrementally impaired waters that would be listed due to the new rule4

. 

FDEP used a different approach for estimating the number of potentially impaired waters 

that would be listed due to the new rule and determined that there are between 424 and 546 

incrementally impaired WBIDs under the NNC rule (FDEP, 2011). The FDEP approach was 

based on a statistical analysis, using the failure rate of assessed waterbodies under the current 

narrative criteria to predict the number of unassessed waterbodies that would fail under the 

numeric nutrient criteria. FDEP developed different statistics for the various “nutrient watershed 

regions” identified by EPA in the new rule (see Table 1-1). While using regionalized statistics 

acknowledges biogeographic and climate differences, no other consideration was given to the 

characteristics of a watershed that may result in impairment. It is unknown whether prior 

information from the currently listed WBIDs is a good predictor of the status of the unassessed 

WBIDs. The size and land use composition of WBIDs varies substantially, which can lead to a 

significant over- or underestimate of the impaired acreage. Thus, it is not possible to determine 

whether this approach represents an upper bound on the incremental number of potentially 

impaired waters due to the new rule. 

A more defensible approach than either of the previous ones would take into 

consideration the characteristics of the various WBIDs to predict the likelihood that they would 

fail to meet the narrative criteria or the numeric nutrient criteria. For example, using the land use 

data and land use management statistics of the assessed WBIDs, one could establish a 

relationship between the likelihood of impairment and the level of urbanization, number of septic 

systems, loading from NPDES-permitted sources, agricultural production, the level of adoption 

                                                           

2 In this section, WBID and waterbody are interchangeable.  WBID is used when citing data on the number and

status of impaired waterbodies from the EPA and FDEP documents.  Also, TMDLs are developed for individual or

groups of WBIDs, so this term is also used when discussing the TMDL process. 3 The NNC rule requires the application of a downstream protective value when choosing the criterion for a stream

segment that enters directly into a lake.  That is, if a stream directly enters a lake and the lake criterion is more

stringent, then the lake criterion would apply to the stream. 4 Assuming EPA’s definition of incrementally impaired.
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of agricultural and stormwater BMPs in a given WBID, etc. The land use information for such 

an analysis is readily available in GIS format. FDEP has a database of septic systems in each 

WBID. Land management information could be obtained from FDACS (for agricultural BMPs 

implemented) or from MS4 permittees (for stormwater BMP adoption). While this approach 

also entails a certain level of uncertainty, the uncertainty should be easier to estimate and report. 

In addition, since the potential incrementally impaired WBIDs can be identified, their specific 

acreage can be considered for the analysis, reducing this source of uncertainty. 

Springs 

EPA identified springs with any monthly geometric mean nitrate-nitrite concentration 

greater than the numeric nutrient criterion as impaired. As with streams and lakes, EPA removed 

from the resulting list of springs those that are currently on Florida’s 303(d) list of impaired 

waters. This analysis resulted in 24 incrementally impaired springs (see Exhibit ES-4 in EPA, 

2010a). Waters with insufficient data to determine compliance were assumed to be unimpaired 

under the numeric nutrient criteria. Thus, the same issues that were discussed above for lakes 

and streams regarding unassessed waters also potentially hold for springs (in terms of the EPA 

number being a lower bound). 

Acreage of Land Draining to Incrementally Impaired Watersheds 

After estimating the incrementally impaired WBIDs, the next step was to determine the 

acreage of various land uses that contribute to the potential impairment. EPA used a relatively 

coarse “grid”, by considering the 10-digit hydrologic units code (HUC10) watersheds, as defined 

by the USGS. Because WBIDs may not fall within a single HUC10, to estimate the incremental 

acreage EPA considered all the HUC10 watersheds containing at least 10 percent of an 

incrementally impaired lake or stream, which may lead to a significant overestimate of the 

incremental acreage (EPA, 2010a). On the other hand, EPA excluded all of those HUC10 

watersheds that contain at least 10 percent of a lake or stream that are currently impaired or 

under a TMDL. This could lead to an underestimate of the incremental acreage. The 

Committee’s evaluation of maps showing the incrementally impaired WBIDs and their 

associated HUC10s did not lead to an obvious conclusion that the HUC10 units are an over- or 

under-estimate of the acreage. 

The HUC10 watersheds are generally too coarse for TMDL analysis, which is typically 

done with a delineation closer to the USGS HUC12 subwatershed level. Figure 2-2 provides an 

example of the resolution of the WBIDs for the Santa Fe River in Central Florida. As can be 

seen, there are dozens of WBIDs within this single basin, of varying sizes. Figure 2-3 presents 

the HUC10s for this same region. There are only seven large HUC10s within this basin. Figure 

2-4 presents the HUC12 delineation for the region. Although there is no direct correspondence 

between the HUC12s and Florida’s WBIDs, the size of the WBIDs is generally much closer to 

the HUC12s. Thus, a more precise estimate of the potential incrementally affected acreage due 

to the new rule could have been performed using the same assumptions but with the HUC12 

delineation of the areas contributing to the various WBIDs. Alternatively, EPA could have used 

the area for each specific WBID for their analysis. 
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FIGURE 2-2 WBIDs in the Santa Fe River. 

SOURCE: McKee (2011).
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FIGURE 2-3 HUC 10 delineation for the Santa Fe river in Central Florida. 

SOURCE: McKee (2011). 
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FIGURE 2-4 Comparable HUC 12 delineation for the Santa Fe river in Central Florida. SOURCE: McKee 

(2011). 

In addition to considering a relatively coarse grid for the analysis, EPA considered that 

every acre of agricultural and urban land in a HUC10 contributes equally to in-stream loading. 

While it is likely that the characteristics of Florida’s WBIDs in some regions, such as artificial 

drainage and highly transmissive soils, may lead to contributions from fields further away from 

the WBID than in other regions around the United States, the coarseness of the grid makes this 

assumption much less valid. While a robust analysis would require a full fate-and-transport 

calculation, an intermediate approach would have considered a distance/travel time weighting 

factor between the contributing croplands and the WBIDs. Using the more refined HUC12 

delineation of subwatersheds would also reduce the error in these estimates of land areas that 

contribute to water quality degradation. 

To estimate the urban areas, agricultural land, and septic systems that may need controls 

to attain the numeric nutrient criteria for springs, EPA obtained GIS data on land areas where 

groundwater aquifers supply water to springs (spring recharge areas or springsheds) from 

FDEP’s Florida Geological Survey. EPA identified incrementally impaired spring recharge 

areas as those vulnerable to surface sources of contamination by the Florida Geological Survey 

Florida Aquifer Vulnerability Assessment (Arthur et al., 2007). The Committee has no concerns 

with this approach. 
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Determination of Incrementally Affected 

NPDES-Permitted Municipal and Industrial Sources 

EPA made the conservative assumption that municipal and industrial wastewater point 

sources would be potentially affected by the NNC rule regardless of the impairment status of the 

WBID in which they are located. To determine the incremental effect of the NNC rule on these 

sources, EPA assumed that wastewater treatment plants (WWTPs) would be considered to be in 

compliance with the NNC rule if they could treat their discharges with advanced wastewater 

treatment (AWT) to reach 3 mg/L for TN and 0.1 mg/L for TP as annual averages. This level of 

performance was selected based on a judgment regarding demonstrated technology that has been 

used at sufficient scale and can be reasonably applied in Florida (see discussion below under the 

subsection entitled “Effectiveness of Control Methods”). These targets for WQBELs for all 

WWTP permittees assume some dilution and assimilation within the receiving waters to meet the 

numeric nutrient criteria at the point of compliance. Whether more stringent effluent limits will 

be required, approaching or in fact equaling the appropriate numeric nutrient criterion, is a matter 

of dispute and is discussed further in this chapter and in Chapter 3.

From the Committee’s reading of EPA (2010), it appears that only municipal and 

industrial point sources that discharge to freshwater lakes and streams were considered in the 

analysis. Municipal and industrial point sources that discharge to groundwater via effluent spray 

fields or rapid infiltration basins were not considered, although they have the potential to lead to 

nitrate impairment in springs. For example, both Ichetucknee and Wakulla springs are suspected 

to be impacted by municipal wastewater effluent spray fields. Lake City’s spray field disposes 3 

MGD of wastewater effluent in the Ichetucknee springshed. The City of Tallahassee’s municipal 

effluent sprayfield disposes of about 20 MGD in the Wakulla springshed. A more conservative 

analysis would have identified all municipal and industrial facilities with effluent sprayfields and 

rapid infiltration basins in incrementally impaired springsheds and assumed that some level of 

additional treatment might be required before disposal of their wastewater. Discussions with 

EPA indicated that they were aware of this possibility, but that available data did not allow them 

to unambiguously identify all relevant municipal dischargers that would affect springs (although 

the data suggested that the number of such dischargers and their capacity was relatively small). 

Thus, EPA judged that exclusion of these dischargers from the cost analysis would not materially 

affect the total cost estimate. The quantitative assessment on which this assumption was based 

was not presented by EPA, making it difficult to determine whether the assumption was 

reasonable, especially from a water quality (as opposed to a cost) standpoint. 

A potential additional industrial cost could exist due to the large number of general 

permits utilized by Florida. A footnote on Page 2-15 of the EPA analysis states there are 34,508 

dischargers covered under general permits in Florida and that EPA did not include those 

dischargers in the analysis. General permits are used to cover a common class of dischargers in a 

streamlined fashion with minimal cost to the permitting authority and the permittee. There is no 

further information regarding the classes of dischargers covered by the general permits. 

However, if any of those general permits relate to industrial facilities discharging nutrients, those 

facilities could potentially lose general permit coverage and be required to obtain individual 

permits. Compliance costs for holders of individual permits are generally higher than for general 

permits. A related uncertainty of this type arises with stormwater sources. At present, most of 

these sources are deemed to be outside the NPDES-regulated process where WQBELs apply. 

However, if this changes due to regulation or third party lawsuits and if the discharge limits that 
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would result are more stringent under the NNC rule than under the narrative rule, then these 

sources could realize greater costs. 

What is assumed about all these regulatory uncertainties has a direct influence on the cost 

estimates reported by EPA and others. Chapter 3 provides a discussion of the regulatory setting, 

and how to best incorporate regulatory and other uncertainties in a cost analysis. The sections 

that follow here focus on uncertainty related to unit costs and effectiveness of controls by sector.

SECTOR COST ASSESSMENTS 

 This review of the EPA economic analysis considered the following issues for each 

sector. First, the overall methods to determine costs were analyzed, focusing on the number of 

affected units and the per unit cost of treatment. For example, for the agricultural sector the 

review considers whether EPA estimated the affected agricultural acreage correctly and the costs 

of BMPs that would be needed for that acreage. Each section discusses the effectiveness of the 

proposed control methods, where appropriate. In doing so, the Committee used the numeric 

nutrient criteria as a threshold for to evaluating the efficacy of BMPs, in the absence of any other 

logical benchmark. Each section describes the relevant sources of uncertainty in the cost 

estimate, including variability in per unit costs, uncertainty in BMP performance, and regulatory 

behaviors. It should be noted that some of the uncertainties discussed are not unique to using 

numeric nutrient criteria (as opposed to narrative criteria); nonetheless, they are discussed here 

because of their potential effect on the cost estimate for a given sector. Finally, the results of 

other competing cost analyses are given and compared to those of EPA. 

Municipal Wastewater Discharges

EPA estimated that $22.3 to $38.1 million/year would be the cost to municipal 

wastewater sources to comply with the proposed NNC rule in Florida. The EPA analysis 

assumed that municipal wastewater dischargers would be in compliance with the NNC rule if 

they could meet the definition of AWT as presented above (discharge limits of 3 mg/L for TN 

and 0.1 mg/L for TP as annual averages). It is important to note the use of an annual averaging 

period for TN and TP in EPA’s cost estimate. Annual averaging means that seasonal variability 

in wastewater discharge pollutant concentrations is averaged out over the course of a year. There 

has been some effort at EPA to enforce average monthly and weekly permit limits based on 

interpretation of 40 CFR 122.45(d) requiring average monthly and weekly permit limits if 

“practicable”. Monthly and weekly limits are not as applicable for pollutants such as TN and TP, 

which do not exhibit toxic effects, as they are for other pollutants typically regulated by NPDES 

permits and which exert their impacts over shorter timeframes than do TN and TP. However, if 

monthly and/or weekly permits were required for TN and TP, the cost of compliance would 

increase due to the need to build increased reliability into treatment plant design. 
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Methods to Determine Costs 

EPA considered that every municipal WWTP had “reasonable potential” under the NNC 

rule, meaning that they might discharge pollutants at levels that would prevent associated 

receiving waters from achieving the numeric nutrient criteria. Thus, their analysis focused on 

determining whether existing plants had already installed removal technologies that could meet 

the targets of 3 mg/L for TN and 0.1 mg/L for TP as annual averages. When both TN and TP 

removal technologies were already installed at a particular WWTP, it was assumed that 

additional modifications were unnecessary and that no cost was associated with these facilities to 

comply with NNC rule. Likewise, when either TN or TP removal technology was installed, only 

the cost to install and operate technology to remove the alternate nutrient was attributed to these 

facilities. This approach is reasonable, as costs for nutrient removal capabilities already in place 

can be attributed to existing nutrient control requirements, not the proposed NNC rule. 

Effectiveness of Control Measures 

AWT technology, as defined by EPA, is an effective and proven approach to achieve the 

specified level of performance, 3 mg/L TN and 0.1 mg/L TP on an annual average basis. 

Effluent TP can be further lowered with similar chemical treatment technology, although at 

increasing cost. TN removal is limited for existing biological treatment technology by the 

presence of soluble, non-biodegradable organic nitrogen which remains in biological treatment 

effluents and is not removable using treatment approaches conventionally applied at municipal 

WWTPs. Soluble non-biodegradable organic nitrogen represents one component of the effluent 

TN and is present at a concentration which is generally in the 1 to 2 mg/L as N range, which is 

sufficiently high to prevent reliable compliance with TN effluent limits below about 3 mg/L. 

Removal technologies such as RO and activated carbon either with or without advanced 

oxidation are available but are in various stages of development and have not been generally 

applied for this purpose in municipal applications. Microfiltration (MF) followed by RO has 

been proposed by some and has been implemented for potable quality reuse applications in 

Orange County, California, and other locations overseas. 

In situations where treatment beyond AWT standards might be required, it is also 

possible that reuse of various types might be an attractive alternative. In fact, reuse is widely 

practiced in Florida to both augment water supplies and to limit direct surface water discharges 

(although reuse for irrigation can infiltrate surficial groundwater and indirectly discharge to 

lakes, streams, and springs). 

These possibilities suggest that simply assuming that MF/RO will have to be applied to 

all municipal dischargers affected by the NNC rule, which is the position taken by the Florida 

Water Environment Association Utility Council (Carollo Engineers, 2010), is also not a 

reasonable assumption. In circumstances such as these, costs to municipal dischargers are often 

limited to established affordability criteria, which would represent one approach to estimate 

upper bound costs for this class of dischargers. 

The footnotes to EPA’s Exhibit 4-3 indicate that WWTPs with the MLE, A2

/O, or 

modified UCT processes5

, and oxidation ditches were considered to be able to comply with the 3 

                                                           

5 MLE = Modified Ludzack-Ettinger; A2

/O = anaerobic-anoxic oxidation; and UCT = University of Cape Town.
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mg/L TN limit; consequently, no costs for TN removal were attributed to them. However, 

evidence exists that MLE, A2

/O, and modified UCT processes are not able to reliably comply 

with a 3 mg/L TN effluent limit (Grady et al., 2011; WEF, 2009), such that further upgrade 

would likely be required for these facilities. Subsequent discussions with EPA made it clear that 

the footnotes were inaccurate, and that in all cases it was assumed that the four-stage or fivestage Bardenpho process was required to comply with the 3 mg/L TN limit. 

Range of Unit Costs 

Unit costs were applied to those NPDES-permitted facilities that were identified by EPA 

as needing upgrades to comply with AWT discharge requirements (see EPA, 2010a, Appendix 

C). EPA estimated the costs for a variety of nutrient control upgrades to existing WWTPs using 

a computerized cost estimating program called CAPDETWorks. Capital, operation and 

maintenance (O&M), and annual costs were determined and expressed on a unit cost basis 

($/gpd of capacity). The detailed basis for their unit cost development is not presented in the 

economic analysis, but the results can be evaluated as outlined below. 

A variety of upgrade approaches was assumed for the three types of required upgrades, 

including TN only, TP only, and TN and TP, as summarized in EPA’s Exhibit 4-4. A reasonable 

range of technologies appears to have been assumed for the TP-only and TN-and-TP upgrade 

scenarios. The range of approaches was used to establish a range of upgrade costs for each 

category of reduction needed and are summarized in EPA’s Exhibit 4-5. 

As noted by EPA, numerous AWT facilities exist in the state of Florida. Logically the 

costs associated with these Florida-specific upgrades would provide the primary source of data to 

establish unit costs. Conversations with EPA indicated that efforts were made to compare their 

CAPDETWorks results with Florida-specific data, and this limited effort indicated that the 

CAPDETWorks data were consistent with Florida experience. As noted by EPA in these 

discussions, the costs specifically associated with nutrient upgrades must be segregated from 

other project costs when analyzing actual cost data. Alternate data were supplied by the Florida 

Water Environment Association Utility Council suggesting significantly higher AWT upgrade 

unit costs. This Committee is not in a position to determine which set of unit costs are correct, 

although as noted by EPA such data must segregate nutrient upgrade-related costs from other 

costs included in the subject projects. It does suggest, however, that direct examination of actual 

state of Florida AWT upgrade unit costs could resolve this matter. Collaboration between EPA 

and the Florida Water Environment Association Utility Council seems a prudent step forward. 

Sources of Uncertainty 

Two sources of uncertainty are potentially significant for this sector. The first relates to 

the unit treatment costs. Significant and relevant experience exists in the State of Florida 

concerning the costs required to upgrade municipal WWTPs to comply with AWT treatment 

requirements of 3 mg/L TN and 0.1 mg/L TP. This information could have been compared to 

the unit costs estimated using CAPDETWorks to determine whether the estimates developed 

using CAPDETWorks were of the proper order of magnitude. Data provided by the Florida 
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Water Environment Association Utility Council suggests that Florida-specific unit costs may be 

significantly greater than those based on CAPDETWorks and used by EPA in their analysis. 

The second significant source of uncertainty is regulatory, specifically the proportion of 

WWTPs that would be required to treat to levels more stringent than 3 mg/L TN and 0.1 mg/L 

TP, perhaps approaching numeric nutrient criteria values in their discharge. EPA assumed that 

no WWTP would be required to treat to levels more stringent than AWT. While this assumption 

makes the analysis simpler to complete, it has been challenged by others, and the basis for those 

critiques is explained as follows (and explored further in Chapter 3). 

Past experiences suggest that the “default” expectation for municipal WWTPs that are 

discharging to waters not meeting established ambient water quality criteria is for them to treat 

their effluent to levels equal to the established ambient water quality criteria. There is no reason 

to suppose this expectation to be different if numeric nutrient criteria are established. 

Nonetheless, EPA assumed that SSACs, variances, or use designation modification would be 

pursued and obtained. (Variances are a regulatory tool to temporarily waive the numeric nutrient 

criteria and they are typically used to relax point source permit limits while the point source 

accrues capital to make treatment upgrades.) However, even if approved, these decisions are 

subject to third-party law suits. Thus, it is reasonable to think that, in at least some instances, 

treatment to levels beyond the specified AWT performance standards would be required, 

resulting in greater cost. 

As noted above, treatment technologies to achieve end-of-pipe compliance with the 

numeric nutrient criteria are not well developed and demonstrated, suggesting that significant 

advances in technology would be required before this becomes an option for municipal 

dischargers to reliably pursue. Also, past experience suggests that pursuing SSAC, variances, 

and use designation modifications can be a long and expensive process with little certainty of a 

successful outcome. Developing alternate effluent management options such as reuse has been 

successfully pursued in Florida, but this requires time as they must achieve public acceptance 

and must be integrated into an overall water supply and management strategy for the community. 

Furthermore, one must consider the possible indirect movement of enriched reuse water through 

the subsurface to receiving waterbodies. 

Other Analyses 

An alternate analysis of the costs associated with municipal wastewater discharges 

complying with the NNC rule was developed for the Florida Water Environment Association 

Utility Council (FWEAUC) by Carollo Engineers (2010). Carollo’s estimate was significantly 

higher than EPA’s for several reasons: 

 85 municipal WWTPs were included in the EPA analysis, while 110 were included in the 

Carollo analysis. 

 The unit costs for upgrading WWTPs to AWT used by Carollo were significantly higher 

than those used by EPA. 

 Carollo assumed that municipal WWTPs would need to meet the numeric nutrient criteria 

at the “end-of-pipe” and thus assumed that microfiltration and reverse osmosis (MF/RO) 

along with brine processing would be needed for all municipal WWTPs. In contrast, 

EPA assumed that municipal WWTPs would not need to meet numeric nutrient criteria at 

the “end of pipe,” but rather the targets of 3 mg/L for TN and 0.1 mg/L for TP as annual 
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averages. Clearly a more thorough analysis than either of these would indicate that some, 

but not all, plants included in this evaluation would be required to upgrade to effluent 

limits more stringent than 3 mg/L for TN and 0.1 mg/L for TP. Efforts could, and 

should, have been made by both parties to estimate the proportion of plants for which this 

would be the case. 

 Because of their assumption about the needed technology, and in some cases the unit 

costs, the overall costs estimated by Carollo were significantly higher than those of EPA. 

Industrial Facilities

 EPA estimated that $25.4 million/year would be the cost to industrial wastewater sources 

to comply with the proposed NNC rule in Florida. The agency identified 108 industrial 

dischargers that would have the potential to be affected by the NNC rule by assuming that any 

dischargers with a Standard Industrial Classification (SIC) that matched those of another plant 

with either existing numeric effluents limits for nutrients or a monitoring requirement for 

nutrients would have similar potential. The potentially affected industrial dischargers 

represented six major industrial categories and 29 different SIC codes. The 108 was winnowed 

down by eliminating 38 plants that have a Waste Load Allocation (WLA) under the existing 

TMDL program. As with municipal WWTPs, EPA assumed that site-specific alternative criteria 

would be granted to those dischargers. EPA also found that 14 of the 108 plants discharge to 

waters already deemed impaired, and thus did not include these plants in their analysis, resulting 

in 56 remaining plants. 

Methods to Determine Costs 

 For the 56 industrial plants, EPA estimated implementation costs by reviewing design 

and performance data from 12 “representative” plants gleaned from the permit compliance 

system. For each industrial category, EPA calculated the average treatment unit cost per MGD 

of flow treated by dividing the total cost for the representative facility by the total flow of that 

facility. EPA then multiplied the average unit cost by the total flow reported in the permit 

compliance system for each of the potentially affected facilities in the applicable category. For 

example, ten mining industrial discharges were evaluated. Two of the ten were sampled to 

develop a cost per MGD of treated discharge, and these numbers were then multiplied by the 

total flow of all ten plants to determine the total cost to this industrial category (about $16 

million). The average unit cost, in $/MGD/year, depended on (1) the nutrient concentration in 

the discharge of the representative plant and how those concentrations compared to the targets of 

3 mg/L N and 0.1 mg/L P, (2) the combined flows within the sampled industrial category, and 

(3) the annualized cost of the technology chosen to treat those discharges. For example, the 

Packaging Corporation of America was chosen as the representative plant for the pulp and paper 

category. That plant was determined to only need P reductions to meet the targets, and chemical 

addition and filtration were the chosen technologies. 

 Limiting the total industry sample size to 12 restricted the primary data (principally flow) 

from which EPA established unit costs and overall industrial point source cost estimates. Given 

the diversity of industries and the variability of their operations and discharges, use of the 
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broader resource database that is available under the permit compliance system would have been 

useful for establishing more accurate cost estimates for the individual industries. It is not clear 

why EPA did not conduct the analysis for all 56 plants. Note that in many cases Basin 

Management Action Plans (BMAP) for existing TMDLs may also provide a broad resource for 

nutrient control cost estimates for both point and nonpoint sources. 

 Additional effort should be put into estimating the costs and impacts of the significant 

dischargers. There are 29 phosphate rock major dischargers (SIC 1475) and 13 phosphate 

fertilizer majors and 17 minors (SIC 2874), as per Exhibit 2-3 of EPA’s economic analysis 

report. Excluding wastewater treatment plants, this is half of the major facilities determined by 

EPA to have nutrient effluent limits or having nutrient monitoring requirements and, according 

to Exhibit 5-3, constitutes 65 percent of the total industrial cost and 8.5 percent of the total 

affected flow. However, a single facility (Mosaic Fertilizer) was used for the entire cost estimate 

for this industrial category with an average flow of 5.24 MGD. Ultimately Mosaic Fertilizer, 

with a flow contribution of less than 0.44 percent of the total industrial flow, exerted a hugely 

disproportionate bearing on the final industrial cost figure. 

 In the industrial analysis (Appendix D of EPA, 2010a), it was suggested that end-of-pipe 

effluent limits should be based on the assimilative capacity of the receiving stream (see examples 

for Pilgrim’s Pride, the Packaging Corporation of America, and St. Mark’s Powder). It is 

unclear if or how assimilative capacity was accounted for in the unit cost development; it should 

only be considered on a site-specific basis and not toward broad industrial sector cost estimation. 

Effectiveness of Control Measures 

 The issues discussed previously for the municipal wastewater discharges also apply to 

industrial wastewater discharges. 

Range of Unit Costs 

 EPA used the same nutrient control unit cost data established for municipal wastewater 

treatment to estimate industrial treatment costs (Exhibit 4-4). The principal problem with 

applying the Exhibit 4-4 data to industrial wastewater treatment costs is the 10 MGD flow basis 

used to establish the unit costs. Industrial wastewater flow rates tend to be much less than 10 

MGD, generally in the 1 MGD or smaller range, such that unit costs tend to be higher and highly 

variable. For example, in Utah’s 2009 nutrient cost study (CH2M Hill, 2010), unit costs to 

upgrade 1 MGD plants for P removal only to an effluent concentration of 0.1 mg/L had an 

average unit cost of about $3.50 per gallon per day design capacity with a range of about $0.50 

to $4 per gallon per day design capacity. Above 10 MGD, the average unit cost was about $2 

per gallon per day design capacity and the range narrowed to about $1.50 to $2.50 per gallon per 

day design capacity. EPA’s unit costs for treatment were generally about $1 per gallon per day 

design capacity, significantly lower than the unit cost in the Utah study. 

 EPA’s cost estimate to add chemical addition and filters for the 55 MGD Packaging 

Corporation of America was $17.7 million, which is low compared to the Utah nutrient cost 

study (CH2M Hill, 2010), where costs to implement similar improvements at five municipal 

facilities of comparable size ranged from $55 to $110 million. 
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Sources of Uncertainty6

 Industrial wastewater treatment cost estimates did not take into account nutrient loadings, 

which can be considerably more variable and dynamic in industrial treatment facilities than in 

municipal wastewater treatment facilities. Differences in nutrient loading, even within an 

industrial category, are extremely difficult to characterize at this level of analysis. One simple 

way of establishing a safety factor to account for industrial discharger load variations would be 

to estimate the requirements for flow attenuation via equalization and include this in the cost 

model. EPA recognized that representative discharger Mosaic Fertilizer (Appendix D) had 

highly variable flows, but it specifically excluded equalization costs from the cost estimate for 

this industry. 

 As suggested above, there is considerable uncertainty in sampling only a subset of the 

industries that would be affected by the NNC rule and using it to derive the cost estimate. For 

the Chemical and Allied Products category, Mosaic Fertilizer’s flow contribution towards the 

total flow of the two samples in that sector was 95 percent [13.9 MGD/14.69 MGD] but no 

nutrient removal cost was determined to be necessary at that facility; only for St. Marks Powder, 

Inc. ($206,800/year). Yet the latter’s flow contribution was only 0.79 MGD. Thus the average 

unit cost for that sector was estimated to be $14,077 [($206,800 + $0)/(0.79 MGD + 13.9 

MGD)]. This figure is skewed considerably lower due to using the cost figure from St. Marks 

Powder but the combined flow from both facilities. Had the average unit cost been determined 

using solely the cost and flow elements from St. Marks Powder, the average unit cost for that 

sector would have increased nearly twenty fold to $261,772 [$206,800/0.79 MGD] and the 

resulting total annual sector cost would have been approximately $20,760,000, not $1,116,800. 

On the other hand, some 34 percent of industrial dischargers reported no flows in the permit 

compliance system. Averaging within the category and discharge type was conducted, which 

tended to bias the costs high, particularly for the major discharger type. EPA should more 

carefully consider how the total annual sector costs may be skewed either higher or lower due to 

cost or flow elements of a small number of individual sector facilities. 

 In its random selection of “representative” dischargers, the Anguila Fish Farm was not 

included by EPA. The flows from this fish farm constitute one-third of the food sector’s flows. 

It is not unreasonable to assume that a fish farm may need to remove significant amounts of 

phosphorus and nitrogen to achieve the numeric nutrient criteria. Thus, not including this single 

facility in the sector sample may have significantly underestimated the total annual cost for the 

food sector. 

Other Analyses 

Several alternate cost analyses, of varying detail, were performed to estimate industry 

costs to meet EPA’s numeric nutrient criteria including Environ International Corp. (EIC), on 

behalf of the Florida Phosphate Industry; Cardno ENTRIX, on behalf of the Florida Water 

Quality Coalition; and FDEP. These cost estimates were significantly higher than EPA’s 

estimate of $25.4 million/year because EPA underestimated both the capital and O&M costs to 

meet the numeric nutrient criteria, while the other stakeholders overestimated the costs by 

                                                           

6 The same NPDES regulatory uncertainty that was described for the municipal sources applies here as well.
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making very conservative assumptions about the technology that would need to be employed and 

the number of facilities that would need to be upgraded. 

 EIC’s analysis was limited to the phosphate industry. Its analysis considered treatment 

endpoints of 1.479 mg/l for TN and 0.359 mg/l for TP and included the cost of treatment for both 

process water and stormwater. On the other hand, EPA considered treatment endpoints of 3.0 

mg/l for TN and 0.1 mg/l for TP and evaluated only industries which have either numeric 

effluent limits and/or monitoring requirements for TN and TP. EIC’s cost estimate was $1.6 

billion in capital costs and $59 million/year for O&M which, when combined, equates to an 

annualized cost of $163.1 million/year (this figure was not presented in its report but rather was 

calculated, for comparison purposes, assuming a 30-year payment period and 5% PVDR). 

 In the Cardno ENTRIX cost estimate, mean annual costs for industrial discharges were 

calculated to be $1.97 billion to meet EPA’s numeric nutrient criteria at the “end-of-pipe,” or just 

$270 million/year for those plants in newly impaired areas to reach the less stringent goal of 

“limits of technology” treatment. Cardno ENTRIX applied a 25 percent contingency factor to its 

estimated cost of compliance, which inflated the results. 

 FDEP’s cost analysis assumed reverse osmosis, a costly treatment alternative, rather than 

biological nutrient removal and chemical precipitation. A second difference is that EPA 

assumed a 20-year payment period and FDEP assumed a 30-year payment period. Thus, FDEP 

estimated the cost of implementing EPA’s numeric nutrient criteria for industrial plants to be 

$2.1 billion/year. 

Urban Stormwater

In the EPA analysis of costs, the urban stormwater sector was the most expensive, 

accounting for approximately 50 percent of the total costs (EPA, 2010a, p. 11-1). To calculate 

this cost, EPA determined the land areas thought to be incrementally impaired under the NNC 

rule and then, based on GIS data, estimated the acreage of urban land that would contribute to a 

potential impairment. 

Methods to Determine Costs 

Some of the challenges to estimating urban stormwater costs for compliance with the 

NNC rule are related to the amount of urban land that drains to incrementally impaired waters, 

the type of urban development, and the historical timeline of that development. First, EPA 

considered that any area urbanized after 1982 would comply 100 percent with FDEP’s existing 

Stormwater Rule (Florida Administrative Code Chapter 62-40.432). This Rule states that 

stormwater management systems must “achieve at least 80 percent reduction of the annual 

average load of pollutants that would cause or contribute to violations of state water quality 

standards;” the requirement for “Outstanding Florida Waters” is 95 percent. Any pollutant that 

can cause impairment to state waters, including N and P, falls under this standard (EPA, 2010a). 

Thus, EPA excluded from its analysis all land developed after 1982, which comprised 28 percent 

of the urban areas in Florida. In doing so, they assumed that stormwater control measures 

(SCMs) designed according to the required state criteria are in compliance with the 80 percent 

reduction standard. 
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Second, EPA assumed that all low-density residential areas would fully comply with the 

existing Urban Turf Fertilizer Rule, and thus should be excluded from the analysis. Because low 

density residential areas represent 58 percent of Phase II MS4 urban areas and 65 percent of nonMS4 urban land, another significant fraction of the acreage was taken out of consideration. 

Scientifically, it is not possible to know the impact of this Rule on meeting the numeric nutrient 

criteria. Nutrient prevention programs are notoriously difficult to quantify, especially when 

stormwater nutrient concentrations rather than load reductions are sought. 

The Phase I MS4 permitting program requires municipalities of greater than 100,000 to 

reduce their stormwater discharges to the maximum extent practicable by a variety of measures 

(NRC, 2009). Given the qualitative nature of the Phase I MS4 permitting program, EPA was 

unsure about whether the acreage covered under that program should be considered to be already 

complying with the NNC rule. To address this uncertainty, EPA used a range in affected land 

area from the assumption of no Phase I MS4 areas to the assumption all Phase I MS4s, and this 

range was propagated through the entire cost analysis. 

While it is true that if these existing state rules were fully implemented the nutrient 

contributions from these areas would be much lower, possibly leading to attainment of the 

numeric nutrient criteria in the corresponding waters, a more robust analysis would assume a 

certain level of non-compliance. The urban areas that may require additional expenditures to 

meet the numeric nutrient criteria may thus be significantly greater than the 23 to 41 percent 

estimated by EPA. On the other hand, it is also unlikely that 100 percent of urban areas would 

be affected due to the new NNC rule, in part because stormwater control measures (SCMs) have 

already been implemented in many urban areas (especially Phase 1 MS4s), and in part because 

not all urban areas contribute equally to the loading of nutrients to potential incrementally 

impaired waters. The use of the more refined HUC12 delineation of sub watersheds would 

improve the estimates of the contributing areas. 

Although EPA acknowledges that urban runoff can be a significant source of nutrient 

pollution to Florida springs, they assume that “efficient land application of nitrogen” will be an 

effective means of addressing nutrients from urban runoff and cite the Urban Turf Fertilizer 

Rule, city- or county-wide fertilizer ordinances, and public outreach and education campaigns as 

good examples of such nutrient source control efforts. Thus, EPA assumed that implementation 

of existing requirements would be sufficient to reduce nitrate-nitrite loads to springs from urban 

stormwater enough to achieve compliance with the 0.35 mg/L NO3-N criteria. Unfortunately, 

there is little empirical evidence that the nutrient source control efforts cited above will reduce 

nitrate from urban runoff/infiltration in springsheds to levels which (when combined with 

nonpoint source nitrate from agricultural land uses in the springshed) will achieve less than 0.35 

mg/L in springs.

Effectiveness of Control Measures 

The efficiencies of SCMs vary widely depending on their type, design, placement, and 

age. Correspondingly, the costs of implementing SCMs to manage urban areas in Florida will 

vary widely on a per-acre basis. Whether the SCMs proposed in EPA (2010) will be sufficient to 

comply with the NNC rule is evaluated by considering the quality of urban stormwater and what 

is known about the effectiveness of SCMs in Florida. 
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Florida Urban Water Quality. A detailed report on urban stormwater in Florida was 

completed in 2007 for the FDEP (ERD, 2007). This document provides a wealth of information 

relevant to Florida stormwater quality and treatment. Detailed evaluation of water quality for N 

and P was presented for six types of urban land use (along with other land uses). Urban 

stormwater pollutant concentrations typically vary by more than an order of magnitude from 

storm to storm and tend to be log-distributed (NRC, 2009). Average concentrations of N and P 

runoff discharge in Florida from urban land uses are presented in Table 2-1.

All nutrient concentrations listed in Table 2-1 are means, taken from various Florida 

research studies. The variability in these concentrations, presented as the standard deviation, was 

calculated from the mean for each individual study evaluated in the report, and is relatively high, 

on the order of 50 percent of the mean value. Although unlikely, it is possible that all land use 

sectors would be required to directly meet the numeric nutrient criteria in their discharges (see 

subsequent section on agriculture). The proposed numeric nutrient criteria range from 0.5 to 

1.87 mg/L TN and from 0.01 to 0.49 mg/L TP, depending upon waterbody type and region. As 

demonstrated in Table 2-1, the urban runoff means for TN ranges from about equal to several 

times higher than the numeric nutrient criteria. For P, the runoff is generally about 3 to 16 times 

greater than the proposed numeric nutrient criteria. 

Stormwater Control Measures. The science and engineering of understanding SCM 

performances is still in its infancy. Specific performance of SCMs for pollutant removals are 

notoriously difficult to quantify due to variations in design, configuration, drainage area land use, 

climate and weather, and surrounding hydrogeology. As a result, from a regulatory perspective, 

urban stormwater control technologies have long been used and operated in a “narrative” mode 

with performance inferred based only on compliance to designing technologies based on specific 

requirements. Most states do this, including Florida. Jurisdictional legislation requires a percent 

TABLE 2-1 Average ± Standard Deviation Nitrogen and Phosphorus Concentrations in Runoff from 

Various Land Uses in Florida 

Urban Land 

Use Category 

Mean Runoff Concentration (mg/L) 

Total N 

80% N 

Reduction 

25% N 

Reduction Total P 80% P 

Reduction 

65% P 

Reduction 

Single-Family 2.07±1.02 0.41 1.55 0.327±0.126 0.065 0.114 

Multi-Family 2.32±1.24 0.46 1.74 0.520±0.017 0.104 0.182 

Low Intensity 

Commercial 1.13±0.045 0.24 0.89 0.188±0.064 0.036 0.063 

High Intensity 

Commercial 2.40±1.03 0.48 1.80 0.345±0.329 0.069 0.121 

Light Industrial 1.20±0.015 0.24 0.90 0.260±0.178 0.052 0.091 

Highway 1.64±0.85 0.33 1.23 0.220±0.146 0.044 0.077 

SOURCE: ERD (2007, pg 4-12, 4-15, 4-16, 4-17, 4-18, 4-19). 

Standard Deviations calculated from data in ERD (2007). 
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reduction of a specific pollutant (e.g., 80 percent removal), but does not specify required numeric 

pollutant concentrations. Because of the variability of natural wet weather events, the use of 

percent removal to describe SCM performance is scientifically weak, and performance 

summaries based on percent removal exhibit high variability. Use of percent removal, however, 

is prevalent and the science to move to another metric is not yet mature. 

Both national and local databases have been created for quantitative monitoring studies of 

urban SCMs. In many cases, the data sets remain small. In all cases, the data are highly 

variable. Different rainfall events will have variable stormwater runoff water quality due to land 

activities, climate, antecedent dry period, and other parameters that remain poorly understood. 

Small, short duration storms may be treated effectively and discharge low pollutant 

concentrations, or even produce no discharge at all. However, large events will result in short 

effective treatment times and resulting poor performance. 

In Florida, variability in urban runoff quality and SCM performance is expected 

geographically throughout the state (ERD, 2007). Most of this is due to variability in annual 

rainfall (Figure 1-4), which averages from about 38 to 66 inches per year. Higher areas of 

rainfall require more expensive treatment, or treatment will be less effective. More runoff is 

expected in the panhandle than in other parts of the state because of the higher annual rainfall, 

requiring greater investment in treatment. Note from EPA Exhibit 3-2 that this region has the 

most stringent numeric nutrient criteria. 

Feasibility of Achieving the Numeric Criteria. Table 2-1 indicates that a reduction of 

80 percent in the N concentration, which is required by the Florida stormwater regulations, 

would on average reduce the N concentration below the proposed numeric nutrient criteria. An 

80 percent reduction of the average P concentration would not comply with the numeric nutrient 

criteria for all regions. (While this simple analysis has disputed scientific support, it is currently 

the best tool available for an analysis such as this.) Because of the log-distribution of runoff 

concentrations and treated SCM discharges, meeting specific concentration criteria for urban 

stormwater runoff would need to be evaluated on the basis on probability and exceedence 

distributions.

A large amount of evidence is available to suggest that 80 percent removal of pollutants, 

including P, is difficult to meet with current SCM technology. EPA (2010) acknowledges the 

wide range of pollutant removal efficiencies expected for SCMs (5 to 85 percent, p.7-2). The 

EPA report assumes that 50 percent N and P reduction would result in nutrient reduction 

necessary to meet proposed numeric nutrient criteria, but Table 2-1 suggests that this is not the 

case. The recent FDEP evaluation of commonly used Florida SCMs (ERD, 2007) suggests that 

wet ponds can accomplish a 65 percent annual mass removal for total P and 25 percent removal 

of TN. A recent NRC report on urban stormwater indicates 45 percent removal for TP and 20 

percent removal for TN for wet ponds and wetlands (NRC, 2009). For dry retention, Florida 

estimates about 53-63 percent P removal; NRC reports 10-20 percent P removal for dry ponds. 

The differences in dry retention pond performances are primarily due to expected greater 

infiltration in Florida soils. Table 2-1 shows that these treatment efficiencies are mostly 

inadequate for reaching the proposed numeric nutrient criteria. 

A removal performance of greater than 93 percent for TP and from 58 to 80 percent for 

TN would be necessary to meet the most stringent numeric nutrient criteria. Traditional 

technologies may not be available to consistently meet these criteria. Greater probability of 

meeting these higher treatment efficiencies could likely be obtained through the use of more 
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advanced SCMs, such as bioretention (up to 80 percent removal of TN and 85 percent removal 

of TP in high-infiltration soils) or other vegetated infiltration practices (NRC, 2009), which may 

be more costly than the per-acre costs populating the existing FDEP database. 

Range of Unit Costs 

The range of costs for stormwater SCMs varies greatly because of the differing value of 

urban lands, the difficulties of construction in (sub)urban areas, and different technologies 

employed as the SCM. Currently, SCMs used in Florida are predominantly detention and 

retention ponds (personal communication, Eric Livingston, FDEP; ERD, 2007). 

A small but valuable database on costs for stormwater control is held by FDEP and was 

used in the EPA analysis. Costs for 40 projects were evaluated; more than half were wet 

detention ponds, followed by dry ponds. The mean is $12,570 per acre, with a standard 

deviation of $14,509 per acre. The median is $6,836 per acre, which is the fixed value used in 

the EPA analysis. (The 10 and 90 percentiles are $863 and $34,350 per acre, demonstrating the 

large variability in unit costs.) 

Traditional SCMs like detention and retention ponds may not be able to meet the numeric 

nutrient criteria themselves, such that urban retrofit of other technologies may be necessary. 

New and evolving technologies may be able to provide better performance for N and P removal. 

Such filtration and infiltration SCMs can have significantly greater per-area costs than traditional 

pond and storage systems (Weiss et al., 2007). A recent article has quoted costs between 

$125,000 and $200,000 per impervious acre for urban retrofit in the Washington, DC suburbs in 

attempts to meet more stringent Chesapeake Bay water quality criteria (Medina and Curtis, 

2011). In retrofit situations, costs for land acquisition must also be included and could be 

significant in urban areas. 

Sources of Uncertainty 

The focus of uncertainty in the EPA report was entirely based on the area of land 

impacted. While this uncertainty is real, it may not be the only or largest uncertainty in the 

stormwater analysis, especially when one considers the inherent variability of rainfall and 

pollutant accumulations on the landscape, in conjunction with variable SCM treatment 

performance. There are several sources of uncertainty other than the one EPA addressed. 

With respect to the land area considered, EPA appropriately considered the urban land 

area developed prior to the 1982 stormwater regulations separately from land developed later. 

An uncertainty, however, is the extent to which land developed after 1982 is actually complying 

with the required 80 percent reduction of N and P; as discussed already, recent studies indicate 

that much poorer performance has been measured (along with a significant degree of variability). 

In addition, new stormwater regulations are anticipated in the next few years that are expected to 

provide greater environmental protection. Gathering information on regulatory compliance and 

SCM longevity and maintenance [all of which can be poor (NRC, 2009)] would provide another 

layer of detail to the cost analysis. 

As noted earlier, the unit area costs for urban SCMs have a very large range. The EPA 

analysis selected only the median value from the FDEP database. Unit costs will vary widely 

depending on the technology selected, on the cost of the land being used for the SCM, and other 
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factors. This cost category is expected to be the greatest uncertainty in the stormwater analysis. 

Interestingly, the EPA analysis used unit cost variability as a prime uncertainty metric for other 

sectors, such as agriculture, but did not carry this methodology to the urban sector. In analyzing 

the other sectors, the land area or unit was always fixed by EPA and the variability was captured 

in the unit cost. 

Finally, refining the cost analysis geographically (by considering rainfall distributions), 

based on the type of urban development and by regional numeric nutrient criteria, would reduce 

uncertainty. 

Other Analyses 

Two stakeholder reports with cost estimates for urban stormwater were made available to 

the Committee, one by the Florida Department of Environmental Protection and the other by 

Cardno ENTRIX (which included a 2011 Addendum). A simple summary of the differences 

among the reports is provided in Table 2-2. The large difference between costs results from the 

land area assumed to require stormwater management. The land areas used by FDEP and the 

Cardno ENTRIX EOP scenario incorrectly include all urban area developed before 1982. These 

two analyses do not limit their focus to incrementally affected areas. The Cardno ENTRIX 

BMP/LOT scenario and EPA appropriately used estimates of the incrementally affected urban 

area only. 

TABLE 2-2 Comparison of Urban Stormwater Costs for the EPA Analysis and Two Others. 

Cost Analysis 

Approximate 

Affected 

Acres 

(thousands) 

Approximate 

Cost per 

Affected 

Acre 

Approximate 

Total Capital 

Costs (M) 

Estimated 

O&M 

Approximate 

Annual Cost (M) 

EPA 61.3–109.4 $6,800 $419–$748 5% $61–$108 

Cardno 

ENTRIX 

BMP/LOT 

scenario 

180 $5,120 $922 5% $61 

Cardno 

ENTRIX 

EOP scenario 

1,878 $5,120 $9,620 5% $630 

FDEP 2,344 $7,295 $17,100 5% $1,967 

BMP/LOT scenario entails Best Management Practices for diffuse sources and the Limits of Technology 

for point sources. EOP scenario assumes that both point and diffuse sources would be required to meet 

the numeric nutrient criteria at the end-of-pipe or edge-of-field. 
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Agriculture 

Agricultural nonpoint sources known to cause nutrient pollution to nearby waterways (as 

identified in Florida TMDL studies) include animal livestock (dairy, cow/calf pastures, poultry), 

citrus, vegetable, and sod farms. For years, BMPs have been developed and implemented for 

agricultural activities to reduce nutrient discharges to nearby waterbodies. A BMP is defined as 

a practice or combination of practices that is technologically and economically effective in 

reducing pollutant loads generated by nonpoint sources to a level that meets water quality goals 

(Mulla et al., 2008)7

. Typically, a BMP reduces pollutant loads while maintaining agricultural 

productivity and being economically feasible to adopt. Adoption of agricultural BMPs is 

voluntary in Florida. Agricultural BMPs have been adopted on over 3 million acres of 

agricultural land in Florida (FDACS Office of Water Policy, 2011a). 

Methods to Determine Costs 

In addressing agriculture, EPA (2010) acknowledges that Florida’s implementation of the 

NNC rule may result in additional BMP requirements to control agricultural nonpoint nutrient 

sources. A primary assumption made by EPA is that the BMPs for agricultural nutrients detailed 

in the Florida Department of Agriculture and Consumer Services’ (FDACS) BMP manuals will 

reduce agriculture’s contribution to the problem sufficiently to meet the NNC rule when 

combined with other source control strategies. 

EPA estimated the incremental cost of new agricultural BMPs only for those agricultural 

lands in “incrementally impaired watersheds”—some 805,793 acres (as estimated by EPA) of the 

13+ million acres in agriculture throughout the state (EPA, 2010a, p. 8-1). EPA also estimated 

that there is an additional 1.1 million acres of crop or specialty agriculture that would be required 

to adopt nutrient management BMPs to attain EPA’s numeric nutrient criteria for springs. In 

terms of the per acre costs, EPA recognized three levels of activities that agricultural producers 

might undertake to make nutrient reductions: the “owner” program which would likely be 

adopted without compensation, the “typical” program which would include government or NGO 

incentives or cost sharing, and the “alternative” program which would be more aggressive and 

costly (and also involve cost sharing). In their analysis EPA assumed that implementing 

“owner” and “typical” BMPs on all agricultural acres in the incrementally impaired watersheds 

and springsheds would be sufficient. The BMP cost estimates of “owner” and “typical” BMPs 

were taken from SWET (2008a). 

                                                           

7

 Florida defines BMPs as cost-effective and practicable management actions for improving water quality and water 

conservation, developed through research, field testing, and expert review. They can be structural (e.g., fencing, 

stormwater ponds) or nonstructural (e.g., managing fertilization and irrigation rates), and may be developed for both 

urban and agricultural use. Agricultural BMPs focus on managing inputs (fertilizer, water, pesticides, herbicides) to 

provide for economic, environmental and agronomic efficiency in production agriculture. SOURCE: FDACS 

(2011b). 
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Effectiveness of Control Measures 

BMP effectiveness can be evaluated through a variety of techniques, including water 

quality trend monitoring and analysis, plot or farm-scale evaluations, paired watershed studies, 

or watershed modeling (Mulla et al., 2008). Each of these approaches has strengths and 

weaknesses. Many farm-scale BMP field studies suffer from (1) a lack of replication; (2) spatial 

heterogeneity in crop management, crop productivity, soils and aquifer properties; (3) year-toyear climate variability; and (4) budget constraints that limit the spatial extent and temporal 

duration of sampling and thus confound rigorous statistical analysis. Nevertheless these studies 

can provide representative examples of surface and groundwater nutrient concentrations 

measured on farms. 

Table 2-3 summarizes some representative water quality measurements from farm-scale 

BMP studies in Florida. In general these measurements represent on-farm measured or modeled 

water quality after BMP implementation. In almost all cases the studies indicate that on-farm 

surface and groundwater samples significantly exceed the EPA numeric nutrient criteria. (As a 

point of reference in reviewing Table 2-3, the numeric nutrient criteria range from 0.5-1.27 mg/l 

TN and 0.011-0.050 mg/l TP for lakes, 0.67-1.87 mg/l TN and 0.06-0.49 mg/l TP for flowing 

waters, and 0.35 mg/l NO3+NO2-N for springs.) These data, along with experience in ongoing 

efforts to reduce nutrient loads to the Everglades and Lake Okeechobee (see Box 2-1), Lake 

Apopka (Bachmann et al., 1999), and the Lower St. Johns River Basin (FDEP, 2008a), do not 

support the EPA’s assumption that typical “owner” implemented on-farm BMPs will achieve the 

proposed numeric nutrient criteria. Rather, Table 2-3 suggests that treatment measures beyond 

typical on-farm BMPs will be required to achieve the proposed numeric nutrient criteria. This is 

further supported by a recent assessment of BMP costs and impacts on water quality in the 

Caloosahatchee River and St. Lucie River watersheds in Florida (SWET, 2008a). Discussed 

extensively in the next section with regard to costs, information on BMP effectiveness in SWET 

(2008a) suggests that the percent reduction in nutrient concentration typically required in a 

Florida TMDL could not be achieved by the implementation of “owner,” “typical,” or 

“alternative” BMPs (see Table 2-4). 
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TABLE 2-3 Representative Water Quality Measurements and Model Predictions from Farm-Scale BMP 

studies in Florida. 

Crop Range of measured 

[N] (mg/l) 

Range of measured 

[P] (mg/l) Situation Reference 

Central Florida 

Ridge Citrus 

(Groundwater) 

4.6-14.0 mg/l 

NO3-N 

NA Measured Post-Nutrient 

and Irrigation 

Management BMPs 

Lamb et al., 1999 

Central Florida 

Ridge Citrus 

(Groundwater) 

3-8 mg/l NO3-N NA Modeled Post-Nutrient 

and Irrigation 

Management BMPs 

Harrison et al., 

1999 

Central Florida 

Flatwoods Citrus 

(Groundwater) 

0.01-0.07 mg/l 

NO3-N 

NA Measured Post-Nutrient 

and Irrigation 

Management BMPs 

Lamb et al., 1999 

Okeechobee Basin 

Cow-Calf (SW) 

2.39-4.26 mg/l TN 0.94-2.25 mg/l TP Measured Post-ditch 

fencing and wetland 

water retention BMPs 

Shukla et al., 

2011a,b 

Okeechobee Basin 

Cow-Calf 

Improved Summer 

Pastures (SW) 

3.35-3.9 mg/l TKN 0.58-0.69 mg/l TP Measured over range of 

stocking densities 

Capece et al., 2007 

Okeechobee Basin 

Cow-Calf semiimproved winter 

Pastures (SW) 

3.16-3.88 mg/l TKN 0.11-0.19 mg/l TP Measured over range of 

stocking densities 

Capece et al., 2007 

Suwannee River 

Basin Row Crops 

(Groundwater) 

23.2-26.5 mg/l 

NO3-N 

NA Measured Post-Nutrient 

and Irrigation 

Management BMPs 

Graetz et al., 2008 

Suwannee River 

Basin Dairy 

(Groundwater) 

0.8-159.5 mg/l 

NO3-N 

0.01-81.44 mg/l 

NH4-N 

0.04-8.45 g/l 

SRP 

Measured over range of 

land uses with Dairy 

Farm 

Graetz et al., 2008 

Suwannee River 

Basin Poultry 

(Groundwater) 

1.6-19.2 mg/l 

NO3-N 

0.01-0.09 mg/l 

NH4-N 

0.01-0.09 g/l SRP Measured over range of 

land uses with Poultry 

Farm 

Graetz et al., 2008 

Sugarcane Everglades Agricultural 

Area (SW)

NA 0.044-0.170 mg/l TP Measured Post-Nutrient 

and Water Management 

BMPs 

Daroub et al., 2011 

Mixed Sugarcane 

and vegetables 

Everglades Agricultural Area (SW) 

NA 0.101-0.165 mg/l TP Measured Post-Nutrient 

and Water Management 

BMPs 

Daroub et al., 2011 

TriCounty 

Agricultural Area 

Row Crops Lower 

St Johns River 

Basin. (SW) 

1-30 mg/l TN 1-14 mg/l TP Measured Post-Nutrient 

and Water Management 

BMPs 

Livingston-Way et 

al., 2001 

TriCounty 

Agricultural Area 

Row Crops, Lower 

St. Johns River 

Basin (SW) 

4-15 mg/l TN 0.36-0.99 mg/l TP Modeled Post-Nutrient 

and Water Management 

BMPs 

Livingston-Way et 

al., 2001 

NA = not applicable; SW = surface water; SRP = soluble reactive phosphorus 
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Box 2-1 

Case Studies of Water Quality Improvements Resulting from 

Implementation of Agricultural BMPs in Florida 

In 1987, the Surface Water Improvement and Management (SWIM) Act was passed by the 

Florida Legislature as a framework for protecting and restoring Florida waters. Its primary focus at the 

time was the restoration of Lake Okeechobee, which is upstream of the Everglades National Park. On 

the northern side of Lake Okeechobee, the primary source of TP to the lake at that time was dairy 

operations (Bottcher et al., 1995). The primary BMPs for controlling this source of pollution are (1) 

collection, pumping, and treatment of drainage waters from High Intensity Areas of grazing to adjacent 

cropland (60-95% reduction in TP concentrations at a cost of $15 to $40/lb of P; SWET, 2008b), and (2) 

collection and land application of barnyard manure on adjacent cropland based on soil testing (10-90% 

reduction in TP). Implementation of diary BMPs on half the land in Taylor Creek, a tributary to Lake 

Okeechobee, was started in 1981. By 1991, these BMPs produced an 84% reduction in TP 

concentrations and a 40% reduction in TP loads discharged to Lake Okeechobee from this tributary 

(Anderson and Flaig, 1995). Additional measures required to further reduce TP loads included 

construction of a 30,000 ac-ft. reservoir to intercept and treat discharge from Taylor Creek (EPA, 2008). 

South of Lake Okeechobee is the 700,000 ac Everglades Agricultural Area (EAA). An extensive 

series of agricultural BMPs were installed for sugar cane and vegetable production in this region from 

1991 through the present (Wan et al., 2001), including both water and nutrient management BMPs. 

Water management BMPs included spatial and temporal water table level controls to reduce drainage 

losses from EAA farms. Nutrient management BMPs included reductions in rate of phosphorus 

application and adjustments in placement and timing of application. Tens of thousands of acres have 

constructed to be Stormwater Treatment Areas. As a result of these actions, TP concentrations declined 

from 173 ppb in the period from 1980-1991 to 69 ppb in Water Year 2004 (Daroub et al., 2005). This 

corresponds to a 64% reduction in TP loads from the EAA. Despite these improvements in water quality, 

the U.S. Sugar Corp. entered an agreement in 2010 to sell the State of Florida 73,000 ac (10%) of sugar 

cane and citrus land in the EAA at a cost of $536 million ($7,400/ac). These lands are to be used for 

wetland restoration and water storage and treatment practices that will further improve water quality in the 

EAA.

TABLE 2-4 Comparison between % reductions in TN or TP required by TMDL studies for Florida lakes or 

rivers and % reductions potentially achievable with implementation of Owner, Typical or Alternative 

agricultural BMPs. 

TMDL Study Percent Reduction in TN Percent Reduction in TP 

Lake TMDL Reductions 24-80 10-85 

River TMDL Reductions 8-45 11-90 

BMP Scenario 

Owner 10-20 9-40 

Typical 5-40 5-29 

Alternative 30-52 25-52 

SOURCE: SWET (2008a). The numbers in the columns are the nutrient reduction percentages actually 

achieved by different types of BMPs (bottom three rows) as compared to that percentage reduction 

required by the TMDL (top two rows).
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Range of Unit Costs 

EPA estimated only the costs associated with the “owner” and “typical” BMPs currently 

practiced in Florida that were assumed to be required in the incrementally impaired watersheds 

and springsheds. A more complete analysis would have also considered the costs for 

downstream regional treatment efforts that may be required to further reduce nutrient levels and 

are often much more expensive. In addition, agricultural land acquisition to limit nutrient 

intensive activities may be a part of a nutrient reduction strategy and, depending on the crop 

produced on the land being restored, that can be very expensive. For example, evidence from the 

Everglades Agricultural Area, Lake Okeechobee, and Lake Apopka restoration programs 

indicates the need to acquire and convert significant areas of agricultural production land into 

regional treatment systems at land costs ranging from $5,575/ac to $7,400/ac. 

The basis for EPA’s unit costs was SWET (2008a), a recent assessment of BMP costs and 

impacts on water quality in the Caloosahatchee River and St. Lucie River watersheds in Florida. 

The dominant land uses in these watersheds are pasture and citrus in the west and urban and 

residential areas in the east. Unfortunately, these watersheds are not necessarily representative 

of the soils, geology, and land uses in large portions of Florida, including the Panhandle, North 

and West Central, and West Central Regions. 

According to SWET (2008a), “BMP implementation costs were typically not provided 

with the research studies and therefore had to be developed by SWET, Inc. Cost estimates took 

into account the following factors: saved fertilizer, equipment and construction, operation and 

maintenance, energy/fuel, crop yield reduction, crop displacement, and land purchases. In 

agriculture, when a BMP requires additional land, such as for retention/detention systems, the 

area is typically carved out of existing land holdings such that there are costs are associated with 

lost crop production (displacement).” Based on these statements it is apparent that SWET 

(2008a) estimated costs contain considerable uncertainty, especially if they are extrapolated from 

southern Florida to the rest of the state. 

 As mentioned above, there are three scenarios for BMP implementation: owner 

implemented, typical cost share incentives, and alternative BMPs including regional treatment 

systems and other practices that take crop land out of production. Cost and effectiveness 

information on all three strategies is given in Tables 2-5 and 2-6 for N and P. “Owner” initiated 

BMPs are the least costly, but result in the smallest water quality benefits. “Typical” BMP 

programs are more costly, but should result in larger water quality benefits. “Alternative” BMP 

programs are more costly than the “typical” incentive-based BMPs, but would also result in 

larger water quality benefits. 

There are many limitations of the approach taken by EPA (2010) to estimate costs of 

BMP implementation in agricultural areas incrementally affected by numerical nutrient criteria. 

First is that the costs of implementing BMPs for water quality benefits are likely to vary 

considerably in different regions of Florida. The SWET (2008a) estimates are based primarily 

on experience with BMPs in the Lake Okeechobee region of southern Florida. Second, is that 

EPA (2010) assumed that BMPs described in the SWET (2008a) owner or typical incentive BMP 

scenarios would be sufficient (in combination with nutrient reduction efforts from other sectors) 

to attain numerical nutrient water quality goals. BMP practices in the alternative BMP scenario 

described by SWET (2008a) will almost certainly be needed in many locations in order to attain 

the numeric nutrient criteria. Thus, it is likely that the actual annual per acre costs of 
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TABLE 2-5 Percent Reductions in Nitrogen and BMP Costs for Three Levels of BMP Implementation in Different Crop an

Systems 

Owner Initiated BMPs Typical Incentivized BMPs A

Production System 

% Reductions Cost ($/ac) Establishment 

Costs ($/ac) 

% Reductions Cost ($/ac) Establishment 

Costs ($/ac) 

% Reductions 

Cow/Calf Production Improved Pastures 

17 4 11 10 12 38.5 30 

Unimproved Pastures 

11 1 2.2 8 4 11 43 

Row Crops 30 3.5 11 30 66.9 209 50 Sugar Cane 10 1 3 23 34 108 52 Citrus 10 6.4 20 5 150.4 470 52 Dairy Production 

20 0.7 2.2 40 334 1043 48 

Hay Production 

15 4 11 25 15 47 36 

SOURCE: SWET (2008a). TABLE 2-6 Percent Reductions in Phosphorus and BMP Costs for Three Levels of BMP Implementation in Different Crop 

Systems 

Owner Initiated BMPs Typical Incentivized BMPs A

Production System 

% Reductions Cost ($/ac) Establishment 

Costs ($/ac) 

% Reductions Cost ($/ac) Establishment 

Costs ($/ac) 

% Reductions 

Cow/Calf Production Improved Pastures 

11 4 11 19 12 38 38 

Unimproved Pastures 

11 1 2.2 29 4 11 43 

Row Crops 30 3.5 11 30 66.9 209 50 Sugar Cane 10 0 2.2 23 34 108 52 Citrus 12 0 5.5 5 24.6 77 52 Dairy Production 

9 2 2.2 28 334 1043 48 

Hay Production 

40 15.8 50 15 4 11 25 

SOURCE: SWET (2008a). 
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implementing BMPs on agricultural land to meet EPA’s proposed numerical nutrient criteria will 

be much larger than their estimates. 

Sources of Uncertainty

An underlying assumption by EPA is that the agricultural lands that would require 

TMDLs and BMAPs under existing state narrative standards would require the same controls to 

meet the proposed numeric nutrient criteria. There is uncertainty as to whether more restrictive 

(or less restrictive) controls would have to be implemented in order to meet the numeric criteria. 

Indeed, one could ask whether the application of “owner” and “typical” BMPs to agricultural 

lands in Florida would actually be sufficient to allow lakes and flowing waters to meet either the 

narrative or numeric standards. If “alternative” measures are required to meet the numeric 

nutrient criteria, the costs and complexities of such efforts increase dramatically. Such measures 

would likely include off-site treatment and the retiring of agricultural lands, as was necessary in 

some of the examples referred to above. 

A second source of uncertainty relates to the effectiveness of the FDACS BMP program. 

Producers who implement and maintain FDACS-adopted BMPs receive a presumption of 

compliance with state water quality standards. The FDACS Office of Agricultural Water Policy 

employs a small staff to follow up with producers to confirm that they are conducting the BMPs 

applicable to their operations. However, enforcement is difficult, and it is not yet possible to get 

an accurate assessment of whether the BMPs selected by the producers are being properly 

implemented and effectively maintained, and to what degree they are improving water quality. 

Other reasons for limited effectiveness include the fact that system complexity and 

implementation costs can be high, labor and especially management requirements are usually 

underestimated, planning horizons tend to be short, and the availability and accessibility of 

supporting resources is limited (Nowak, 1992). Critical to effectiveness are successful 

implementation and then long-term maintenance for the practice or technology. While a farm in 

Florida in an impaired watershed is required to adopt BMPs, which BMPs the grower must 

implement are not specified. There is a substantial gap between what may be required, what may 

be economically feasible, and what may be sufficient to meet the NNC rule that may not be filled 

by voluntary action. 

Other Analyses 

The EPA analysis estimated significantly lower costs for the agriculture sector than the 

analyses of Cardno ENTRIX and FDACS. EPA grouped its agriculture land uses somewhat 

differently: (1) EPA had three classes of cow calf production compared to one for Cardno 

ENTRIX and (2) EPA classified what Cardno ENTRIX calls sugarcane land use as cropland and 

pasture land. This is a fairly important difference because the cost for sugarcane BMPs is about 

twice as much as that for cropland and pasture. Furthermore, the sugarcane land use accounts for 

30 percent of Cardno ENTRIX’s costs of meeting the NNC rule. 

Citrus and hay are the other two large contributors to the cost (about 50 percent), and 

they were treated quite differently by EPA and Cardno ENTRIX. Hay is important because it 

covers a large number of acres, and citrus is important because of the relative high assumed costs 
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per acre for BMPs. In Cardno ENTRIX’s BMP/LOT scenario, their high estimate was that 

937,513 acres of hay land would be affected by the NNC rule compared with 284,378 acres 

estimated by EPA. For citrus, Cardno ENTRIX’s high estimate was 90,142 acres as compared 

with EPA’s 27,343. This discrepancy resulted from Cardno ENTRIX including additional acres 

draining to waters that were “unassessed” and thus not included by EPA. Repeating this across 

all agricultural land use categories resulted in a total difference of about 1.8 million acres 

between the EPA land estimate and that of Cardno ENTRIX. The differences in per acre BMP 

costs cited by EPA and Cardno ENTRIX are large for two reasons: (1) different cost estimates 

for the same BMPs and (2) because of which BMPs were considered necessary to meet the 

nutrient criteria. Furthermore, it is not clear whether the EPA costs included the same extent of 

maintenance and other cost components as Cardno ENTRIX did. While EPA almost surely 

underestimated costs by choosing low-cost BMPs, Cardno ENTRIX’s “end-of-pipe” scenario is 

beyond what would likely be required to meet the NNC rule and represents an overestimation of 

BMP costs (and acres to be treated). 

Both the number of acres requiring BMPs and the cost per acre for BMPs are clearly 

highly uncertain. It is always difficult to predict which BMPs farmers will elect to adopt and 

how well they will maintain them even when they are mandated by regulatory programs. 

Furthermore it is uncertain whether Florida can effectively enforce the adoption and maintenance 

of agricultural BMPs. Both the need for farmer cost-share incentives and the need for effective 

state enforcement will result in transaction costs that neither EPA nor Cardno ENTRIX have 

adequately considered. How much these transaction costs will add to total costs is unclear, but it 

could be as high as an additional 25 to 35 percent (McCann and Easter, 2000). 

On-site Septic Systems

Onsite Sewage Treatment and Disposal Systems (OSTDS) refer to conventional septic 

tank soil absorption systems and include more complex technologies called Performance-Based 

Treatment Systems. Regardless of their complexity, OSTDS have the following fundamental 

distinguishing feature: they treat and return wastewater to the hydrologic cycle close to the point 

where the wastewater was generated (Crites and Tchobanoglous, 1998. pg 2). This commonality 

was schematically represented by Bouma (1979) and is reproduced below as Figure 2-5. The 

figure has been modified to represent septic tank requirements in Florida and to demonstrate a 

septic-tank soil absorption system adjacent to a flowing stream. 

As shown in Figure 2-5, renovated septic tank effluent (percolate) rejoins groundwater 

immediately below the soil absorption area. Due to the slight groundwater table gradients found 

in Florida, a plume of septic-influenced groundwater moves very slowly away from the 

discharge point. 

The average home in Florida on an OSTDS discharges approximately 11 pounds of 

nitrogen per person per year (FDOH, 2010a), and approximately 4 pounds of phosphorus per 

person per year (Lowe et al., 2009). As percolate from an OSTDS moves down gradient, 

microbiological and chemical reactions convert nearly all the nitrogen to nitrate while 

phosphorus is held back in the effluent plume due to adsorption and precipitation reactions 

(Wilhelm et al., 1994). 
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 FIGURE 2-5 Idealized Individual On-Site Sewage Treatment and Disposal System Flow Diagram. 

SOURCE: Bouma (1979). 

Methods for Determining Costs 

To determine the costs of implementing the NNC Rule for septic systems, EPA 

considered the 793,697 active septic systems in the FDEP database, and then determined which 

of those systems lie within the potential incrementally impaired WBIDs. Acknowledging that 

septic systems contribute differentially depending on subsurface transport distance to the 

waterbody, EPA considered only those septic systems that are within 500 feet of a potential 

incrementally impaired waterbody. This reduced the number of septic systems considered for 

the EPA cost analysis to 8, 224, or just over 1 percent of all the systems in the state of Florida. 

For the 8,224 OSTDS, EPA assumed that they would require upgrades for nitrogen and 

phosphorus removal to comply with the NNC rule. 

Although necessary to facilitate their analysis, choosing 500 feet as the cutoff distance for 

OSTDS nitrogen and phosphorus impacts is a critical and as-yet unsubstantiated assumption in 

EPA’s analysis. A greater distance (e.g., 1000 ft) would take into consideration the specific 

hydrogeologic conditions in Florida. For example, in areas within the Biscayne Aquifer or in 

karst geologies, groundwater velocities are so rapid that a 500-ft setback distance could be 

traversed in just a few days. However, for the vast majority of the state 500 feet is a realistic 

starting point. That is, it would require months for nutrients discharged 500 ft from a stream or 

lake to reach the waterbody and in that intervening time, both dilution and removal (adsorption 

of P, denitrification of N) would likely reduce the ultimate concentration discharged. 

EPA assumed that no additional controls would be needed for septic systems to attain the 

nitrate-nitrite criterion for springs, claiming that the contribution of nitrogen from septic systems 

is highly uncertain and likely site specific. They cited Brown et al. (2008) as indicating that the 

preponderance of nitrogen pollution in Florida springs appears to be from fertilizer sources, not 

septic tanks and wastewater sprayfields. Although Brown et al. (2008) do state that the 

preponderance of N pollution appears to be from fertilizer sources, they also explain that there 

are several reasons to treat this finding as an over-generalization, and point out that there remains 

significant uncertainty about the interpretation of bulk stable isotope measurements (that are used 

to distinguish nitrate from mineral sources versus municipal effluent or septic tanks) in complex 

karst hydrologic systems. A more conservative assumption would have been for EPA to assume 
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that all septic tanks in incrementally impaired springsheds would require upgrade to advance 

nutrient removal systems.

Effectiveness of Control Measures 

 EPA recommended the use of advanced nutrient removal systems for the 8,224 OSTDS 

that would require upgrades to comply with the proposed NNC rule. The effluent standards for 

this designation were not given and EPA said it was unclear whether retrofit technologies could 

be used. The Performance-Based Treatment Systems technologies mentioned in EPA’s report 

are capable of meeting advanced secondary effluent standards of 20 mg/L TN and 10 mg/L TP. 

Although further reduction in both parameters are likely in soil absorption and transport, 

achievement of the actual numeric nutrient criteria is not guaranteed before an OSTDS plume 

reaches the property line. 

 EPA did not consider the use of permeable reactive barriers, which were found to be low 

cost in the Chesapeake Bay watershed and able to achieve a nitrate discharge of 5 mg/L (EPA, 

2010b). They are the only known technology likely to be able to approach the proposed numeric 

nutrient criteria in their discharge. However, permeable reactive barriers have their own 

limitations, since they have to be replaced on a timed schedule and the longevity of the media is 

not well understood (Robertson and Cherry, 1995). In the Florida Keys a layer of phosphorusabsorbing media 24 inches thick was used directly beneath the soil absorption area to achieve 

phosphorus removal to less than 1 mg/L (Ayres Associates, 2000); it was predicted to have a 

lifespan of 10 years. Unfortunately, no media performs both nitrogen and phosphorus removal 

simultaneously. 

Range of Unit Costs 

 Using interviews with manufacturers and published cost data, EPA estimated the 

annualized capital cost of upgrades, assuming 7 percent interest over 20 years, to be between 

$800 and $1,300 per OSTDS. It is not clear that this simple analysis took in account a number of 

important factors that should be included in estimating the costs of OSTDS upgrades. Under 

Florida law, all such upgrades would be considered Performance-Based Treatment Systems, 

which must be designed by a Florida Licensed Professional Engineer. Typical design fees range 

from $1,000 to $2,000. Permit fees for Performance-Based Treatment Systems are $125 for the 

initial application and $100 for a biennial operating permit. Performance monitoring of 

Performance-Based Treatment Systems, including laboratory analysis, can be expected to range 

from $400 to $800 per year. In the Florida Keys, which has the highest proportion of 

Performance-Based Treatment Systems in the state, total annual construction and operational 

costs for nitrogen and phosphorus reducing systems were estimated at between $1,730 and 

$2,841 (Ayres Associates, 2000). 

 In order to install a permeable reactive barrier a hydrologic survey including 

determination of groundwater elevations would be necessary. Typical fees for such services 

range from $500 to $1500. In the Chesapeake Bay watershed (EPA, 2010b) anticipated 

installation costs of permeable reactive barriers ranged from $5,000 to $15,000 per home. 
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Sources of Uncertainty 

Of the two metrics that need to be estimated to determine the range of costs for septic 

systems to implement the NNC rule, the number of units affected is the more uncertain than the 

per unit cost because springs areas were excluded from the analysis. There is also regulatory 

uncertainty. Unlike for the other sectors, implementation of the NNC rule for septic systems 

could not occur as quickly and unilaterally because the FDEP must work through the Florida 

Department of Health (FDOH), which has responsibility for regulating OSTDS in the state of 

Florida. The two agencies interact formally through an interagency Memorandum of 

Understanding (MOU) and meet monthly to discuss issues of mutual interest. FDOH rulemaking 

involves the in-depth participation of a stakeholder group called the Technical Review Advisory 

Panel (TRAP). All meetings of the TRAP are conducted in accordance with Florida’s Sunshine 

Law. Any person can bring forward proposed rule revisions for consideration by the FDOH and 

discussion by the TRAP. Florida’s OSTDS rule (64E-6, Florida Administrative Code) has been 

revised approximately once every two to four years over the last decade. 

Other Analyses 

In responding to EPA (2010), FDEP made several extreme assumptions regarding actions 

needed to make septic systems compliant with the NNC rule. First, it assumed that conventional 

septic systems on lots larger than three acres would automatically comply with the NNC rule, 

and thus assumed no additional costs on three-acre or larger lots. A review of the FDOH 

permitting databases indicates that approximately 83 percent of new septic systems and 

approximately 90 percent of older systems were on lots less than 3 acres. FDEP chose an overall 

estimate that 85 percent of septic systems were on lots less than three acres. 

Rather than assume a specific cutoff distance from an incrementally impaired waterbody, 

FDEP assumed that 75 percent of all septic systems discharge to groundwater that eventually 

becomes surface water. Thus, the number of septic systems in Florida that they included in the 

cost estimate was 1,687,500 (as opposed to EPA’s estimate of 8,224) (FDOH, 2010b). Although 

EPA’s assumption of a 500-ft setback can be criticized as an arbitrarily low cut-off for septic 

systems that might contribute nutrients (given the prevalent and highly transmissive soils and 

karst geology), FDEP’s assumption that nutrient contributions from throughout the state will 

impact flowing waters in Florida equally is also questionable. 

FDEP assumed that all affected septic systems would be upgraded in the first year (called 

instant replacement), which is extremely expensive. Even assuming a more reasonable 5 percent 

per year replacement over 20 years, FDEP’s annual cost estimates ranged from $0.9 to 2.9 billion 

because of the larger number of systems considered. 

Cardno ENTRIX revised their economic analysis in July 2011 and made major changes 

in their analysis regarding septic systems to take into account additional geospatial data on septic 

tanks and new FDOH information on the likely incremental compliance costs associated with 

septic systems. Cardno ENTRIX accepted a 500-ft setback in refining the number of septic 

systems affected. Their overall estimate of annual compliance costs for septic systems was 

between $2 to $18 million dollars, with a mean estimated annual cost of $8 million dollars. This 

estimate is much closer to the $1.3 to $2.2 million estimated by EPA. 
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Government Costs

EPA (2010) assumed all incremental costs to government associated with the 

promulgation of the NNC rule would accrue exclusively in the development of total maximum 

daily loads (TMDLs). EPA reviewed potential incremental costs associated with developing 

site-specific alternative criteria and ambient monitoring, but determined these costs were 

insignificant. The incremental cost of TMDL development was reduced to a function of the 

numbers of incrementally impaired waters requiring TMDLs and the estimated cost of TMDL 

development. As noted previously, the key cost variable is likely to be the number of impaired 

waters. The potential number of incrementally impaired waters varies widely depending on the 

assumptions used to identify impairment. Thus, the number of impaired water/pollutant 

combinations significantly affect the government cost component as well as have a cascading 

effect on the overall cost estimate. 

Methods for Determining Costs 

The methodology for determining government costs is found in Chapter 10 of EPA’s 

economic analysis performed in support of promulgation of numeric nutrient criteria for Florida 

(EPA, 2010a). Since the primary variable in the cost analysis is the number of incrementally 

impaired waters, Chapter 10 ties back directly to Chapter 6 where the estimate of incrementally 

impaired waters requiring TMDLs can be found. Exhibit 6-1 of the EPA analysis presents data 

in a tabular format summarizing EPA’s analysis of incrementally impaired waters and arrives at 

a total of 325 waters that include streams, lakes, and springs. EPA further assumed that multiple 

waters would be included in a single TMDL document. Based on the average of previous 

Florida TMDLs, EPA estimated two waterbodies would be incorporated into each TMDL 

bringing the number of new TMDLs associated with the NNC rule incremental impairment to 

163. 

Several assumptions are used to estimate the number of incrementally impaired waters, 

including two key assumptions that eliminate certain groups of waters. Those key groups 

include waters with existing or proposed TMDLs for nutrients and those waters with insufficient 

data. If EPA accepts all existing nutrient TMDLs as a means for reaching endpoints compatible 

with the NNC rule, then the assumption that no additional TMDL work will be required for those 

waters with preexisting TMDLs is valid. If any of those existing TMDLs are challenged as not 

reaching suitable endpoints, then there will be added cost for modifying those TMDLs. 

The larger uncertainty lies with the elimination of waters determined by EPA to lack 

sufficient nutrient data. As reported in EPA’s Exhibit 6-1, only 34 percent of the waters without 

existing or pending TMDLs were thought to have sufficient data. Thus, 66 percent or 3,169 

waters were eliminated for lack of sufficient data. As described earlier in this chapter, FDEP 

later tried to determine which of the 3,169 waters with insufficient data would potentially be 

identified as impaired using EPA’s numeric nutrient criteria and concluded that 1,018 of the 

3,169 currently un-assessed waters would potentially be listed as impaired and require TMDLs 

when assessed against the numeric nutrient criteria. Using EPA’s estimate of two waters per 

TMDL, an additional 509 TMDLs would potentially need to be developed, more than tripling the 

current EPA cost estimate. This Committee advocates for an alternate approach to determining 
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the number of unassessed waters likely to be out of compliance with the numeric nutrient 

criteria, which takes into consideration the characteristics of the various WBIDs. 

Range of Unit Costs 

The cost estimate for completing a TMDL was estimated based on a draft EPA document 

evaluating TMDL program costs (EPA, 2001a). EPA utilized an average cost per impairment of 

$28,000 based on a range of $6,000 to $154,000 per impairment. Those costs represent an 

aggregate of costs for all pollutants with no indication as to whether nutrient TMDLs would be 

more or less costly than other pollutants. EPA further assumed that each TMDL would be 

written for two impairments, TN and TP. This is a reasonable assumption because most of the 

incrementally impaired waters would be impaired for both TN and TP. The cost of the second 

impairment was discounted because much of the background information would have been 

collected for the first impairment. The second impairment was estimated to cost $6,000 (the low 

end from the 2001 EPA document). The costs of the two impairments were added and the total 

was brought forward to 2010 dollars resulting in a unit cost of $47,000 per TMDL. 

The EPA (2001a) document included multiple cost ranges for developing TMDLs: the 

cost for single impairments; the cost for waterbodies with single to multiple impairments; and the 

cost per state submission which included multiple TMDLs for clustered waters. Interestingly, in 

the Executive Summary of the 2001 document, EPA references only the waterbody cost estimates 

in approximating aggregate national TMDL unit costs. Those unit costs utilized for the national 

estimate range from $26,000 to $500,000 per TMDL with an average of $52,000 dollars. 

Inflating that average cost to 2010 dollars using EPA’s multiplier yields an average cost of 

$72,000, or 1.5 times the cost used in EPA’s analysis. It is not clear why the 2010 EPA 

economic analysis did not use the $52K cost, as the 2001 document is frequently cited, which 

implies that $52K is the best overall nationwide estimate of TMDL development costs. Perhaps 

there was a sound reason for the selection of a lower unit cost, however no reason was stated. 

The 2010 cost analysis also notes that the additional costs for monitoring needed to develop 

TMDLs were not included in the cost estimates. 

Although not cited in the EPA analysis, the support document for the TMDL program 

costs (EPA, 2001b) provided additional detail on the methodology used to compute costs. A 

matrix of costs was developed based on the degree of complexity of a TMDL and the efficiencies 

realized by performing TMDLs for multiple pollutants and/or waterbodies versus single 

pollutants. The data indicate the cost for a single pollutant, single waterbody TMDL ranged 

from $36,284 for a simple TMDL to $69,924 for a moderately complex TMDL to $123,476 for a 

complex TMDL. All costs are in 2000 dollars. Those costs inflated to 2010 dollars are $50,240; 

$96,500; and $170,400, respectively. Costs for a second parameter at each of the complexity 

levels are estimated to be $11,978; $28,779; and $56,741 in 2000 dollars, respectively. Inflating 

those costs to 2010 dollars and adding them to the costs for the original parameters yields the 

total costs for two parameter TMDLs on single waterbodies as $66,800 for a simple TMDL, 

$136,200 for a moderately complex TMDL, and $249,000 for a complex TMDL. These 

estimates range from 1.4 to 5.3 times higher than the analysis used in EPA (2010). 

Regardless of the unit cost selected, the TMDL cost data discussed above are over a 

decade old. Bringing the cost of the original estimates up to current dollars may be acceptable as 

an estimate. However, use of contemporary or Florida-specific data may have provided a more 
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accurate estimate of actual TMDL costs. The FDEP Office of Inspector General (FDEP, 2008b) 

produced a report detailing FDEP TMDL program costs, including operations funding, for the 

program through 2007. Based on operations funding and the numbers of TMDLs completed, it 

appears a Florida-specific cost estimate for TMDL development could have been developed. To 

develop a crude but rapid understanding of what the number would have been, the following 

calculations are provided: 

 Operations costs from FY02-06 were 21.51% of the total TMDL program costs. 

Operations costs included “...expenditures such as staff salary, travel, monitoring, 

contractor services, TMDL development and BMAP implementation.” The BMAP 

implementation and follow up monitoring would go beyond TMDL development costs, 

but the numbers provided in the report did not go into additional detail. 

 Total TMDL costs through FY08 totaled $156.5M. So the estimate of operating costs = 

$156.5M X 0.2151 = $ 33,663,150.00 

 As of the 2008 OIG report, there are 156 TMDLs adopted, 100 TMDLs in the process of 

being adopted, and 83 TMDLs being developed. So one could estimate 256–339 TMDLs 

developed. Thus, the range of average cost = $33.6M/339 to $33.6M/256 or $99,000 - 

$131,000/TMDL. 

In terms of more contemporary data, EPA has contracted with various consultants for 

TMDL development throughout the country. It is likely contemporary cost estimates for TMDL 

development could be calculated based on those contractual arrangements. It may also be 

possible to parse out the specific cost of developing nutrient TMDLs from those data. At a 

minimum, the value of the contracts could be used to gauge the general accuracy of the 2000 cost 

estimates. 

Other Cost Considerations 

Other costs associated with complying with the NNC rule could have potential fiscal 

impacts to government bodies other than TMDL development. This document will not attempt 

to quantify those costs, only to identify the possible additional costs to government. In addition 

to the potential costs mentioned below, there could conceivably be new administrative, 

monitoring, and enforcement costs if FDEP ramps up its efforts to address waters newly 

impaired under the numeric nutrient criteria, but these are not discussed further. 

SSAC Development Costs. In the section on municipal and industrial wastewater 

treatment plants, the EPA analysis assumed there would be liberal acceptance of variances or 

SSACs to replace the promulgated numeric nutrient criteria on a case-specific basis. SSAC 

development costs could be borne by government sector or the private sector, but the possibility 

of the former was not factored into the government sector analysis done by EPA. Regardless of 

who develops the SSAC, government time and resources would have to be spent evaluating and 

ruling on the acceptance or denial of the SSAC, and on evaluating variance requests, but these 

costs were not considered in the EPA analysis. The history of using SSACs and variances for 
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nutrient issues is virtually unwritten on a national level. Thus, their use in Florida would be 

breaking new ground. 

Second round and later costs for TMDLs. EPA assumes all TMDL costs occur over a 

nine-year period and then end. In reality, many adaptively managed TMDLs will have to be 

evaluated after the nine-year period and adjustments made to the TMDL to further reduce 

nutrients. While not as costly as the original TMDL development, there are costs involved in the 

re-evaluation of those TMDLs. 

Potentially Lower Stream Criteria Based on Downstream Protective Values. Once 

EPA promulgates numeric nutrient criteria for estuaries, those criteria could force lower nutrient 

concentrations in streams in order to meet the estuary criteria. Lower mandatory stream 

concentrations could result in additional waters being assessed as impaired, thus increasing the 

number and complexity of the TMDLs which must be developed. 

Sources of Uncertainty 

Government costs as analyzed by EPA are tied exclusively to TMDL development. 

Thus, a significant uncertainty for the government sector is the number of waterbodies that may 

be impaired and require a TMDL. Different estimates put that number between 325 and 1,018. 

While there is also a large percentage difference in the unit cost of each TMDL estimated by 

EPA as compared to others, the gross cost per TMDL is small in comparison to implementation 

costs in other sectors.

Another significant unknown is that FDEP maintains they will be unable to develop 

TMDLs and BMAPs for waters deemed impaired according to the EPA numeric nutrient criteria 

due to Florida state law prohibitions on the use of criteria not contained in state rule (FDEP, 

2010). If that is the case, EPA will be forced to take the lead in both identifying nutrient 

impaired waters and developing TMDLs and BMAPs. Since EPA has no track record of 

developing nutrient TMDLs, it is unclear what an EPA TMDL would look like, how it would be 

implemented, and what it would cost. All of EPA cost estimates assume the State of Florida will 

implement the numeric nutrient criteria. It is anticipated that costs could be significantly higher 

if EPA were responsible for a nutrient TMDL program because EPA would have initial start up 

costs in establishing an infrastructure capable of assessing Florida’s waters, developing TMDLs, 

and following up on BMAP implementation. 

Other Analyses 

Cardno ENTRIX (2011) performed an analysis of government cost as a part of their 

overall review of EPA’s cost analysis. Their Monte Carlo analysis of the data led to a prediction 

of 902 additional waters would be listed as impaired under the numeric nutrient criteria. The 

analysis also estimated a higher unit cost for each TMDL using EPA’s minimum and maximum 

unit costs as model inputs. Based on the analysis, Cardno ENTRIX estimated a TMDL unit cost 

of $64,000 as opposed to the EPA estimate of $47,000. 
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To determine the total government costs, Cardno ENTRIX considered two scenarios—(1) 

Best Management Practices for diffuse sources and the Limit of Technology for point sources 

(BMP/LOT) and (2) End-of-Pipe (EOP) assumption that both point and diffuse sources would be 

required to meet the numeric nutrient criteria at the end-of-pipe or edge-of-field. The results of 

the Monte Carlo simulation, which provide a range of cost from low to high, are given in Table 

2-7 and range from $1 million to $11 million with a mean of $6 million. The EPA cost estimate 

of $0.9 million is near the low-end Cardno ENTRIX estimate. 

While the difference between $0.9 million and $6 million is very significant in terms of 

state government budgeting, the government costs are a small fraction of the overall cost of 

implementation—less than 1 percent. Therefore, the government costs play an insignificant role 

in terms of the total costs for implementing numeric nutrient criteria. 

TABLE 2-7 Cardno ENTRIX Total Government Cost Analysis 

Millions $  

Estimated Annualized Cost

Estimated Present Value Cost:

2011‐2040   

Assumption

5th

Percentile

95th

Percentile Mean

5th

Percentile

95th

Percentile Mean

Monte Carlo

Output

BMP & LOT   $1 $4 $2 $11 $65 $32 $29

End of Pipe

Criteria $3 $11 $6 $43 $175 $93 $85
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FINDINGS AND RECOMMENDATIONS 

The first set of findings and recommendations pertain to the determination of the number 

of incrementally impaired waters, and as such have repercussions for several of the sector 

analyses. A second set of findings and recommendations are provided that are specific to each 

sector, preceded by a summary table. All of these findings and recommendations are based on 

the assumption that EPA would use the same basic method for any future economic analyses, 

with the intent of making suggestions for improvements. 

Incrementally Impaired Waters and Watersheds

FINDING: The HUC10 delineation used to assess the acreage of various land uses that 

contribute to the potential impairment is too coarse. 

RECOMMENDATION: EPA should use the more refined HUC12 delineation to generate a 

more precise estimate of the acres to consider for the BMPs in the various land uses. 

FINDING: It is not valid to assume that the percent of unassessed waters that would be 

incrementally affected is zero. A more defensible approach would take into consideration the 

characteristics of the various WBIDs to predict the likelihood that they would fail to meet the 

narrative criteria or the numeric nutrient criteria. 

Sector Analyses 

Table 2-8 summarizes the Committee’s assessment of EPA’s economic analysis by 

sector. The color coding of Table 2-8 entries reflects the Committee consensus of the accuracy 

of the EPA evaluation. Green indicates a satisfactory job in addressing the issue, yellow 

indicates only moderate agreement, and pink indicates unsatisfactory assessment. 

The table is based on the cost method used in the EPA analysis, in which the total sector 

cost was calculated as the product of the number of affected units (or area) and the unit cost. The 

second column refers to how well EPA determined the number of affected units, including 

judgments on assumptions used for the number of point discharges that will require treatment 

upgrades and land areas that will need to have new BMP technologies implemented. The third 

column deals with the accuracy of unit costs assessments. 

The fourth column considers whether the numeric nutrient criteria could be met by 

existing technologies at the “end-of-pipe” or “edge-of-field” for each sector. The EPA analysis 

assumes that in every case assimilative capacity exists somewhere in the watershed or 

waterbody, or that administrative relief is available, such that the each sector does not have to 

meet the numeric nutrient criteria at the end-of-pipe or edge-of-field. Yet the EPA has not 

employed watershed modeling to determine if implementing all assumed technologies would 

allow the numeric nutrient criteria to, in fact, be met. From the regulatory standpoint, if a 

waterbody violates the numeric nutrient criteria, its assimilative capacity is considered to already 

be exceeded. Thus, the numeric nutrient criteria were used in this column because no other 
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TABLE 2-8 Summary of Key Findings by Sector 

EPA estimate of

the area affected

or number of units

EPA estimate of the

unit cost of BMPs

Can chosen tech‐

nologies/BMPs

meet the NNC?

Strategies to improve the

analysis

Municipal

Plants

All WWTPs

included due to

“reasonable

potential”

provisions of

regulations

CAPDET Works cost

estimates not

verified using

Florida‐specific

experience

Assumed that

WWTPs would

only be required

to treat to 3 mg/L

TN and 0.1

mg/LTP and none

will treat to NNC

at end of pipe

1.  Ground truth unit costs

based on significant existing

Florida experience.

2.  More realistically reflection

of the proportion of WWTPs

receiving administrative relief

to avoid treating beyond 3

mg/L TN and 0.1 mg/L TP.

Industrial

Plants

Established by

averaging flows

from only a limited

number of facilities

and extrapolating

to others.

CAPDET Works

program (used for

municipal facilities)

was misapplied to

industries.

Same as for

municipal WWTPs

Should not have investigated

only 1 or 2 plants per SIC but

rather analyzed each plant

Agriculture EPA likely under

estimated the area

of incrementally

impaired

watersheds as well

as the number of

springs affected

Costs from SWET

report not

representative;

need more site‐

specific cost

estimates  

No.  Alternative

BMPs will likely

be required along

with land

retirement

Use existing TMDLs and

restoration plans to identify

the BMPs and regional

treatment needed to meet

the criteria

Urban

Stormwater

Assumed Urban

Turf Rule would

insure compliance

on all low‐density

residential land and

that all land after

1982 is already in

compliance.  

EPA used low end

of a very wide

range of unit costs  

Assumed

traditional BMPs

would meet NNC

and assumed

100% compliance

and functionality

for urban BMP

implementation.  

NNC may

necessitate more

advanced BMPs.

Consider advanced BMP

implementation throughout

most developed land area.

Septic

Systems

Excluded systems

beyond 500 ft and

springs areas

Reasonable for

technologies

evaluated.

Not necessarily,

but other

technologies may.  

Consider wider range of

systems and updated per unit

costs.

Government

Costs

Did not consider

other government

costs like SSAC

approval, variances,

etc.

Used old TMDL cost

data not specific to

FL

NA 1.  Use contemporary, Florida

and nutrient‐specific TMDL

development costs.

2.  Consider costs of SSACs,

TMDL revision, etc.

logical benchmark is available with which to compare the performance of technologies and 

BMPs. 

An important consideration not well captured in this summary table (but returned to in 

Chapter 3) is the degree of uncertainty and variability expected in each of the sector categories. 
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In many cases, uncertainty is expected to be exceedingly high. While some uncertainty is 

captured in the EPA analysis, it is not considered to be adequate to describe the vast complexity 

inherent in many of the parameters critical to the economic analysis. In some of the sectors, 

especially with agriculture and with urban stormwater, technology and implementation unit costs 

can vary by factors approaching two orders of magnitude. Placing the assessment accuracy 

results summarized in Table 2-8 in the context of the high uncertainty and variability of many of 

the categories leads to even greater concern with the EPA economic analysis. 

Municipal Wastewater Treatment Plants 

FINDING: There is significant uncertainty in the cost estimate for municipal wastewater 

treatment plants because (1) the unit treatment costs were not verified by comparison to the 

existing and extensive Florida AWT treatment experience and (2) the assumption that no plant 

will be required to treat to levels more stringent than 3 mg/L TN and 0.1 mg/L TP is unrealistic. 

While the proportion that will be able to avoid treating to levels more stringent than 3 mg/L TN 

and 0.1 mg/L TP is uncertain, there is a real possibility that at least some WWTPs will have to 

treat to more stringent levels. 

RECOMMENDATION: Efforts should be made to compare the unit costs of CAPDETWorks 

with cost data from Florida. Efforts should also be made to better estimate the percentage of 

plants that will be required to reach discharge limits more stringent than 3 mg/L TN and 0.1 

mg/L TP by performing mass balance and dilution calculations for at least a representative 

proportion of plants, if not for all of the plants included in this analysis. 

Industrial Plants 

FINDING: There is significant uncertainty about the incremental cost of the NNC rule for 

industrial plants for several reasons. EPA based its estimates on one or two selected facilities 

from each sector and ignored the diversity of industrial facilities within a sector. This 

extrapolation led to some low-flow facilities exerting a disproportionate influence on the overall 

industrial costs. Furthermore, the same cost model and treatment processes were used for 

industrial facilities as was employed for municipal WWTPs. For facilities with highly variable 

flows, flow equalization may be a more cost-effective solution than mechanical/ chemical 

treatment, such that EPA may have overestimated costs for these facilities. On the other hand, 

some industrial facilities have higher unit costs than municipal WWTPs. Finally, industries 

covered under general permits were not investigated, raising the question of whether there may 

be costs to remove nutrients from those facilities that were not captured in EPA’s estimates. 

RECOMMENDATION: Given the small number of industries involved, the cost analysis should 

be improved by analyzing each plant rather than extrapolating the results of one or two plants to 

the entire sector. As with the municipal wastewater treatment plants, efforts should be made to 

compare the unit costs of CAPDETWorks with cost data from Florida and to better estimate the 

percentage of plants that will be required to reach discharge limits more stringent than 3 mg/L 

TN and 0.1 mg/L TP. 
Assessment and Commentary on EPA’s Analysis 73 

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Urban Stormwater 

FINDING: For the urban stormwater sector, the costs of complying with the NNC rule in those 

watersheds determined by EPA to be incrementally impaired are expected to be higher than EPA 

estimates. However, high uncertainty and variability is prevalent throughout all aspects of this 

sector analysis, which would lead to a wide cost range and costs that are highly dependent on 

several critical assumptions. Most traditional Florida urban SCMs will not likely be able to 

comply with stringent numeric nutrient criteria, but newer, novel (and more expensive) 

technologies may. Per acre costs for traditional Florida SCMs are highly variable; broadening 

the SCM options increases the cost range even more. Many simplifying assumptions are 

employed to estimate urban land area incrementally affected by the NNC rule. Actual affected 

land area estimates are highly dependent on unverified existing SCM performance and 

compliance with urban stormwater rules and regulations. 

RECOMMENDATION: To improve the cost analysis, higher-efficiency SCMs should be 

considered, which have costs higher than traditional SCMs. Costs of retrofitting SCMs into 

already-developed land should be considered. 

Agriculture 

FINDING: For the agricultural sector, the costs of complying with the NNC rule in those 

watersheds determined by EPA to be incrementally impaired are likely to be higher than EPA 

estimates. The incremental land area needing treatment was likely underestimated, individual 

costs for the BMPs assumed to be sufficient were underestimated, and the more effective and 

costly BMPs and regional treatment systems likely required to meet numeric nutrient criteria 

were not included in the analysis. The need for more stringent BMPs and treatment systems has 

been demonstrated in many of the BMAPs developed for impaired waters in Florida. 

Furthermore, there were some critical omissions that could well lead to increased costs, 

including the degree of actual participation by agricultural producers and the costs of 

maintaining BMPs over time. 

RECOMMENDATION: To improve the cost analysis, actual experience from existing TMDLs 

should be used to identify the BMPs and regional treatment systems that were sufficient or 

insufficient to meet certain numeric targets. 

Septic Systems 

FINDING: For septic systems, the costs of complying with the NNC rule in those waterbodies 

determined by EPA to be incrementally impaired are likely to be substantially higher than EPA 

estimates. The Committee was comfortable with the 500-ft threshold assumption made by EPA; 

however, the exclusion of septic systems in springsheds is a significant deficiency of EPA’s 

analysis. EPA received cost estimates from vendors of equipment capable of meeting a total 

nitrogen target of 20 mg/l and a total phosphorus target of 10 mg/L, values which are much 

higher than EPA’s numeric nutrient criteria.
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RECOMMENDATION: Efforts should be made to consider septic systems in springsheds and a 

wider range of systems including permeable reactive barriers, which are known to be more 

effective in removing nutrients to levels consistent with the numeric nutrient criteria. 

Government Costs 

FINDING: The incremental costs for the government sector are expected to be higher than EPA 

estimates. The key factors in determining government cost are the number of incrementally 

affected units (WBIDs requiring a TMDL) and the unit cost of a TMDL. In the EPA analysis, 

WBIDs with insufficient data were not used, thus potentially underestimating the number of 

incrementally impaired waters requiring TMDLs. Unit costs were based on low-end estimates of 

costs from a 2001 study that focused on a broad range of TMDL work not specifically related to 

either Florida TMDL development or nutrient TMDL development. The unit cost selected was 

less than the national unit cost referenced in the 2001 report. 

RECOMMENDATION: Effort should be made to quantify costs for Florida-specific and/or 

nutrient-specific TMDLs to provide more accurate unit costs for TMDL development. 

Additional government costs should also be considered, including costs for developing or 

approving SSACs and variances, costs associated with downstream protective values effectively 

reducing upstream criteria, future costs of adaptively managed TMDLs, and consideration of 

additional waters becoming impaired in the future.

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Chapter 3 

A Framework for Incremental Cost Analysis of a Rule Change 

INTRODUCTION 

EPA’s estimate of the incremental cost from implementing numeric nutrient criteria in 

Florida was reviewed in Chapter 2. The EPA analysis first estimated which waters would be 

listed as impaired under the numeric nutrient criteria (NNC), but were not yet listed under the 

existing narrative rule. That estimation assumed that these waters would not have been listed as 

impaired under the narrative rule. The corresponding watersheds for these incrementally 

affected waters were then delineated, and their land uses were determined in order to predict the 

additional nutrient control actions various source sectors in that watershed would need to take for 

the numeric nutrient criteria to be met. In addition, EPA estimated how many National Pollutant 

Discharge Elimination System (NPDES)-permitted municipal and industrial sources that 

discharge to inland surface waters anywhere in the state would have revised concentration limits 

for nitrogen (N) and phosphorus (P) in their discharge permits. These two changes were how 

EPA defined the incremental effect of the NNC rule. 

In writing its review in Chapter 2, the Committee accepted the EPA definition of the 

incremental effect and provided a critique of the methods by which that incremental effect was 

empirically developed. Chapter 2 reviewed the EPA estimates of the unit costs and effectiveness 

of EPA’s chosen load reduction methods, concluding that there was much uncertainty about both 

the costs and effectiveness of the methods. Of course, that uncertainty would be present under 

any rule. 

This chapter proposes an alternative framework for conducting a cost analysis, with an 

emphasis on defining the implementation time paths of the various rules and consideration of 

uncertainty. The chapter begins by describing the difference in the rules according to what is 

required in EPA’s 2010 Guidelines for Preparing Economic Analysis (EPA, 2010a). Those 

guidelines call for first establishing a baseline “defined as the best assessment of the world 

absent the proposed regulation”, including identifying starting and ending points over time for 

the baseline scenario (EPA, 2010a, p. 5-1, 5-2). To develop such a baseline for this chapter, the 

water quality management process is divided into five broad stages, and a description is provided 

of how the narrative rule, the NNC rule, and the proposed Florida rule would affect each stage 

over time. By comparing the three implementation time paths, with the narrative rule as a 

baseline, one can isolate the differences in the rules in order to determine how these differences 

might affect costs. In fact, many of the differences in cost estimates made by EPA and others 

can be traced to different assumptions made about how the rules would affect actions taken in 

each of the stages. 
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That discussion is followed by presentation of a framework for predicting incremental 

costs of the various rules. In describing the logic of the framework and graphically illustrating 

its application, the text demonstrates that predictions of costs over time depend on many 

assumptions about (1) current and future regulatory agency behavior, (2) future political and 

legal decisions and interpretations, (3) waterbody response to load reductions, (4) unit costs of 

current load reduction activities, (5) changes in cost and effectiveness of load reduction 

activities, and (6) socioeconomic, demographic, and land use change. Indeed, what was assumed 

about these various factors explains the differences in the EPA and stakeholder estimates of the 

cost of the NNC rule. Use of this framework can highlight differences in assumptions, help to 

narrow differences in the cost estimates if similar assumptions can be agreed to, and highlight 

how uncertainties can be reduced analytically or by clarification of ambiguities in the rules. 

What the framework also suggests is that the results of all cost analyses are contingent on the 

assumptions made by the analysts and that it is an unrealistic expectation of any analysis to 

produce a single, agreed upon cost estimate. 

COMPARING THE NARRATIVE AND NUMERIC NUTRIENT CRITERIA RULES 

For the purposes of this comparison, the water quality management process shown in 

Figure 1-8 was divided into five stages. This section summarizes the actions taken during those 

five stages under the narrative rule (which is considered the baseline), under the NNC rule that 

was the motivation for this report, and under the recently proposed Florida rule which EPA has 

agreed to consider as an acceptable replacement for the NNC rule. The following descriptions of 

the rules were derived from detailed flow charts created by the Committee for each rule (see 

Appendix A). 

Description of the Rules 

The five stages begin with the identification of impaired waters and end with an 

evaluation to ascertain when the designated use is met. The stages are shown as row headings in 

Table 3-1. The cells in the table are abbreviated descriptions of the rules’ content. 

Stage 1: List Waters as Impaired 

Stage 1 establishes whether a waterbody is going to be listed as impaired. The narrative 

rule uses various biological condition indices (depending on the type of water body) as criteria to 

serve as a proxy measure for the designated use. The water is listed when evidence that the 

biological condition is unacceptable becomes compelling. To be deemed compelling, the data 

must be adequate in quantity and quality. If the monitoring data are deemed inadequate, the 

water is placed on a planning list for further evaluation, before it can be placed on the verified 

list of impaired waters. 

The proposed Florida rule also requires violation of biological criteria for placement on 

the verified list, but streams will be placed on the planning list if nutrient concentrations exceed a 

threshold value. To move a waterbody from the planning list to the verified list requires 
A Framework for Incremental Cost Analysis of a Rule Change 81 

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confirmation of biological impairment. In addition, the proposed Florida rule includes a 

provision to place waters on the planning (not verified) list if they show an adverse trend in 

biological response variables or dissolved oxygen (DO), even if waters did not fail any of the 

biological indicators. 

The NNC rule measures ambient concentrations of nutrients (N and P) in the water and 

compares those to ambient concentration criteria that were established for reference water bodies 

in the region, according to water body type. If the monitored concentration exceeds either 

criterion then the water is deemed to be impaired, even though there may be no measured 

biological impairment. 

Because the NNC rule offers explicit limits for ambient nutrient concentrations, listing 

proceeds at a faster pace than under the narrative or the proposed Florida rule due to the more 

complex evaluation that is required under that latter two for biological assessments. However, 

the proposed Florida rule will place streams on a planning list if they exceed a nutrient threshold 

or show adverse trends in measurements of dissolved oxygen or biological condition. Thus, the 

proposed Florida rule could expedite the identification of waters that are likely to be impaired 

due to nutrients as well as the development of TMDLs and Basin Management Action Plans 

(BMAPs) for those waters, relative to the narrative (but not the NNC) rule. 

Stage 2: Establish Stressor 

Stage 2 in the narrative rule determines whether nutrients are the stressor causing the 

impairment. This determination is based on analytical procedures (stressor–response 

relationships) to establish whether N, P, or both are causing the impairment and at what levels 

might they be creating unacceptable biological conditions. The FDEP may also presume that 

nutrients are one stressor if the level of N or P is above a threshold concentration in reference 

waters. If the narrative rule determines that one or both nutrients are the cause of unacceptable 

biological conditions, nutrient targets as loads or concentrations are established as an outcome of 

the TMDL process during Stage 3. The proposed Florida rule is essentially the same as the 

narrative rule for this stage. 

Stage 2 under the NNC Rule is less explicit because during Stage 1 the NNC Rule has 

already listed a water as impaired based on the presence and level of nutrients. However, the 

NNC Rule does recognize the possibility that there may be site-specific conditions that warrant 

different criteria and it allows for any entity to petition EPA for approval of site-specific 

alternative criteria (SSAC) for a specific location (http://www.epa.gov/region4/water/wqs/). The 

petition could result in a change in the nutrients to be controlled (to either N or P, as opposed to 

both) and/or changes to the ambient concentrations of either nutrient. This petition can be filed 

with EPA at Stage 2 (or at any other stage) after a water is listed as violating the numeric nutrient 

criteria. According to draft EPA guidelines (EPA, 2011), the FDEP can submit any waterbody 

with an existing TMDL-derived target (if expressed as a concentration) for approval as an SSAC. 

It is uncertain whether the TMDL targets will be accepted as SSACs, although EPA cites a 

memo that says targets can be SSACs for the interim purpose of setting NPDES permit limits. 
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TABLE 3-1 Comparison of Narrative, Numeric, and Newly Proposed Florida Rule For Nutrients. 

Stage Narrative Rule Numeric Nutrient Criteria Rule Proposed Flo1. List Waters as Impaired 

Based on biological impairment for streams, lakes, and springs 

N and P assumed to cause impairment if criteria are exceeded and water automatically placed on verified 303(d) list. Streams and Lakes: 

 N and/or P exceeding criteria  Point sources subject to permits 

containing N and/or P limits 

Springs: Nitrate exceeding criterion 

Streams and La

 Based on 1) 

nutrient threimpairment, 

Springs: Nitrate 

2. Establish Stressor Determine if N and/or P are stressor(s) 

causing biological impairment 

Petitioners have opportunity to seek EPA approval of site specific alternative criteria (SSAC) to replace the NNC for P, N or both. 

Streams and Lastressor(s) causi

 If stressor i

303(d) list fadditional s

 If adverse n

water w/in study list 

 If adverse n

water w/in 303(d) list 

Springs: No streexceeded

3. Define Level of 

Nutrient Reduction/Write TMDL 

Model water quality conditions to relate desired biological condition to N and/or P loads; Determine N and or P targets 

Model water quality to determine loads of N and P that result in ambient N and P numeric criteria concentrations 

Streams and Lato relate desired levels; DeterminSprings: Load rthreshold

4. Develop TMDL/ 

BMAP Implementation 

BMAP process seeks WLA/LA load reduction balance across sources 

WLA set by NPDES permitting process/ LA the remainder for non-point source. 

BMAP process balance across 

5. Determine Use 

Attainment 

Biological condition attained; N and P targets revised to be consistent with meeting required biological condition. 

N and/or P ambient concentration of NNC or SSAC must be met. Biology may or may not remain impaired. 

Biological condrevised to be cobiological cond
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Stage 3: Define Level of Nutrient Reduction/Write TMDL 

At Stage 3, a narrative-rule-driven TMDL will establish concentration or load targets that 

are predicted to secure an appropriate biological index. The targets may be for N or P, but not 

necessarily both. It is also at this stage that the waste load allocation and load allocation are 

established. This division between the waste load allocation and load allocation is based on 

Florida policy (FDEP, 2001). 

Stage 3 occurs similarly under the proposed Florida rule. As currently written, the 

proposed Florida rule affirms that a numeric TMDL target approved by EPA under the current 

narrative rule would be the numeric nutrient target for that waterbody. This is not a change from 

the narrative rule, but under the NNC rule the waters that already had a TMDL and a nutrient 

target would have still been required to define that target as a concentration (if it was only a load 

limit in the TMDL), relate the concentration to biological response, and submit that 

concentration as a proposed site-specific alternative criteria (SSAC) to EPA. 

The TMDL analysis under both the narrative rule and the proposed Florida rule requires 

models that relate loads to ambient chemistry and then to the biological conditions. These will 

be more complex than the models required for an NNC-derived TMDL. The difference in 

TMDL model complexity and the different ways that the waste load allocation is defined 

between the NNC and the narrative rule may allow for the development of a TMDL more 

quickly under the NNC rule. Also, the NNC rule may accelerate the reduction of loads from 

NPDES-permitted municipal and industrial sources because a water quality-based effluent limit 

(WQBEL) may be set for those discharges independent of and prior to the TMDL. 

The NNC-based TMDL will be established using models that relate nutrient loads to the 

ambient concentrations, as defined by the criteria. The NNC rule will establish a TMDL to 

assure that concentrations are met for both N and P, unless there is approval of a SSAC. These 

WQBELs may define the WLA with the residual load allocation being given to the non-NPDES 

permitted sources. 

Stage 4: TMDL Development/BMAP Implementation 

At Stage 4, the narrative rule and the proposed Florida rule implement load reductions by 

writing NPDES permit limits as a part of the BMAP to implement the TMDL. As the NPDES 

permits are issued to secure the waste load allocation, the plans for the non-NPDES sectors are 

prepared and implementation begins, employing the various tools available, to meet the load 

allocation. 

Under the NNC rule, it is possible that permit limits for point sources may be established 

as early as Stage 1, thus focusing the TMDL on defining the load allocation. A key difference of 

opinion about the requirements in Stage 4 hinges on what is assumed about the way the NNC 

rule affects the NPDES permit limits and when that effect occurs. Otherwise the pace of 

development for the implementation plans is the same for all three rules. 
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Stage 5: Determine Use Attainment 

Stage 5 tracks implementation and continues monitoring of ambient waterbody 

conditions. If the criteria are met then a determination is made that the designated use has been 

attained. However, monitoring does not stop and loads limits must continue to be maintained in 

the face of population and economic growth to assure that the water does not become impaired at 

a future date. The narrative rule and the proposed Florida rule focus their determination of 

attainment on ongoing bioassessment along with measurement of all stressors. If the TMDL 

target concentration is met, but biological conditions are not, the TMDL and implementation 

plan are revised to require further reductions in load, unless a Use Attainability Analysis is 

submitted and approved. If the biological criteria are met before the nutrient targets are met, the 

TMDL and implementation plan may be revised and further load reductions would not be 

required. 

Under the NNC rule, monitoring for nutrient concentrations and load reductions will 

continue until the numeric nutrient criteria are met. There is always the opportunity to petition 

EPA for an SSAC to shows that reductions are no longer needed to meet the designated use. 

Key Differences Among the Rules 

Listing and Stressor Assessment 

The selection of the biological criteria that best represent the designated use and the 

determination of “data sufficiency” to determine impairment are central to the execution of the 

narrative rule. If the criteria are acceptable proxies for the designated use1

, the determination of 

whether the data are sufficient to establish impairment is, in effect, a decision on acceptable error 

when making a listing and stressor assessment. 

The narrative rule makes an impairment determination based on biological conditions and 

then moves to further analysis to determine if that the impairment is attributable to nutrients (N 

or P or both) and at what levels. This further analysis defines targets for N and P that are 

predicted to protect the designated use. A listing based on numeric nutrient criteria 

simultaneously concludes that either or both nutrients N and P (depending on ambient nutrient 

concentrations) are the cause of failure to meet the designated use. 

In the language of statistics, the null hypothesis is that the water is not impaired. A type I 

error is concluding that the water is impaired when it is not. A type II error is concluding that 

the water is not impaired when it is. The likelihood of error is not of interest in itself; what is of 

interest is the cost of making that error. The cost of a type I error is making load control 

expenditures from a limited budget that were not necessary to meet the designated use of one or 

more waterbodies—called the cost of over-control. The cost of type II error is the water quality 

benefits that are lost when a waterbody is not listed as impaired when it is impaired and so load 

controls are inadequate—called the cost of under-control. 

 

1

 The extent to which the biological criteria are adequate in representing the designated use is one concern of critics 

of the narrative rule; that is, if the criteria are inadequate then the criteria may be met, but the designated uses will 

not be. The result will be that water quality benefits will be forgone, even as the criteria are met. 
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While it is not possible to clearly conclude which rule is more prone to which type of 

error, there are some general observations that can be made. The advocates for the narrative rule 

want to avoid making a type I error (that is, they want to avoid over-control). The proposed 

Florida rule continues this focus on avoiding type I error, but in an effort to recognize and 

accommodate the type II error it includes the modification to Stage 1 and 2, described earlier, in 

which waters with downward trends in chemical condition are put on a planning list. The NNC 

rule advocates want to avoid type II error (i.e., under-control), and in an effort to recognize and 

accommodate the possibility of a type I error, it includes the SSAC rule. 

Table 3-2 further describes the differences in the rules as responses to the cost of error. 

Case 2 suggests that if the SSAC rule is not employed, the NNC-listed waters may be listed 

incorrectly for N, P, or both, leading to a misallocation of TMDL planning and load reduction 

efforts and costs. Cases 2, 3, or 4 suggest that the NNC rule can be too limiting, or not limiting 

enough, on discharges of P, N, or both. If the NNC rule were to replace the narrative rule, and if 

the SSAC option was not employed, there could be cases of both over control and under control, 

with the associated costs of each error. These are not hypothetical possibilities; rather a 

comparison of TMDL nutrient targets with the numeric nutrient criteria suggests these 

differences are real possibilities (see Box 3-1). All of this suggests that the SSAC rule, including 

its likely use and cost, is very important when describing the differences in the rules. 

According to the draft guidelines (EPA, 2011), the SSAC rule would be based on 

analytical approaches that provide evidence, satisfactory to the EPA, that alternative levels of N, 

P, or both will protect the biological designated uses for both the waterbody and any downstream 

waters. It is reasonable to conclude from the draft guidelines that the analytical approaches that 

might be used to support a request for an SSAC are similar to those analyses already in use in the 

narrative rule. For example, a place-based stressor response analysis might be prepared for the 

SSAC application to demonstrate that a concentration of nutrients different from the numeric 

nutrient criteria would support the designated use. In the narrative rule, a similar place-based 

stressor response analysis is often used to identify what nutrient levels could exist and still be 

supportive of the designed uses (Stage 2). 

TABLE 3-2 Narrative and Numeric Nutrient Criteria Rules Differences for a given waterbody. 

NNC not Exceeded NNC Exceeded

Biological Condition 

Acceptable in WBID 

and downstream 

Case 1. Neither rule would list the 

waterbody as impaired.

Case 2. Numeric rule would list the 

waterbody as impaired for N, P or 

both; some entity could petition 

EPA for a SSAC. Narrative rule 

would not list the water as impaired. 

Biological Condition 

Not Acceptable in 

WBID and 

downstream

Case 3. NNC rule would not list the 

water as impaired. Narrative rule 

would list the waterbody, then 

ascertain if the stressor was nutrients 

and if so it would set nutrient targets. 

Case 4. Both rules would list the 

waterbody. Narrative rule would 

develop targets that could be 

greater, equal to, or lower than 

NNC. 
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Box 3-1 

Do Numeric Nutrient Criteria Differ Significantly From 

Nutrient TMDL Targets Developed Under Narrative Criteria? 

Data were provided in Appendix H (Exhibit 2-8) by EPA (EPA, 2010b) for waters that have been 

through Stage 3 of the narrative process and already have nutrient targets assigned by the FDEP. These 

data were examined to draw a preliminary conclusion about whether the numeric nutrient criteria would 

differ from the nutrient targets. However, these conclusions cannot be extended to waters that have not 

been through Stage 3 of the narrative process because the results are not based on a random sample of 

impaired waters but rather are based on data from those waters that are already have targets. The 

narrative rule will put a priority on the places where the impairments are most obvious and so the existing 

narrative targets may not be representative of the targets that would be established for other waters in the 

future. Within this limitation, the results showed the following: 

 Narrative TMDL targets for river nitrogen are generally lower (i.e., more stringent) than numeric 

criteria 

 Narrative TMDL targets for river phosphorus are lower than numeric criteria 

 Narrative TMDL targets for lake nitrogen are generally lower than numeric criteria 

 Narrative TMDL targets for lake phosphorus are generally higher than numeric criteria 

In general, additional load reductions will be required for lakes determined to be impaired for phosphorus 

under the NNC rule compared to the narrative rule. However, in the case of impairments for river nitrogen 

or phosphorus, or for lake nitrogen, lesser load reductions would be required by the NNC rule than with 

the narrative target. 

There are other key differences between the rules at Stage 2, if not in the analyses 

themselves. The SSAC occurs after a waterbody is listed as impaired for nutrients and is only 

completed at the discretion of a petitioner (such as a state agency, discharge source, or a 

nongovernmental organization, NGO) who would seek an alternative to the numeric nutrient 

criteria. Therefore, even though the SSAC opportunity exists, it may not be taken and so there 

may be no costs for the SSAC. In addition, under the NNC rule, waters that have an established 

nutrient TMDL target that is less stringent than the numeric nutrient criteria with respect to N or 

P loads would need to be submitted to EPA for approval as SSAC. 

NPDES Permitting and BMAP Differences 

The EPA economic analysis assumed that there would be no differences in NPDES 

permit concentration limits or when the limits would be established if the narrative criterion was 

replaced by the numeric nutrient criteria. Under the CWA, the presence of a numeric limit for an 

ambient concentration of a pollutant (in this case N and P) may replace the best-availabletechnology requirement in setting an NPDES permitted source effluent limit with a water quality 

based effluent limit (WQBEL). The WQBEL may come into effect as soon as a water is listed as 

impaired by the NNC rule (Stage 1), even if a TMDL has not been written and a BMAP put in 

place. Also the NNC rule creates the possibility that the ambient numeric nutrient criteria 

becomes an end-of-pipe concentration limit, or a limit that must be met at the edge of a defined 

mixing zone, if a mixing zone is allowed. For these reasons, it is reasonable for point source 
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dischargers to assume that the numeric nutrient criteria, derived from outside a TMDL, 

eventually must become NPDES effluent concentration limits, although temporary variances are 

possible. This temporary relief may be extended if the source seeks and gains approval for a use 

attainability analysis or SSAC. Conversely, in the narrative rule the effluent limit for a point 

source is developed integral with the TMDL process, so until the TMDL is in place, the NPDES 

permit is based on the best available technology. 

The TMDL process, once completed, assigns a waste load allocation to the NPDESregulated sources; the waste load allocation may or may not result in effluent concentration 

limits equivalent to the numeric nutrient criteria, even for waters where the ambient target is 

more stringent than the numeric nutrient criteria, under the FDEP allocation (FDEP, date). At 

this point the TMDL and follow-on BMAP can allocate responsibility for load reduction to nonNPDES sources that might otherwise have been assigned to the NPDES sources under the NNC 

rule. 

A COST ANALYSIS FRAMEWORK 

The various cost estimations of EPA and other stakeholders differed according to the 

assumptions made about how the different rules are implemented. Conceptually, the incremental 

costs of adopting the NNC rule or the proposed Florida rule is the change in costs over what 

would have occurred under the existing narrative rule during all five stages of water quality 

management. Defining the baseline involves identifying both current and future conditions that 

would exist without the regulatory change over the period of analysis (EPA, 2010a). This 

requires making assumptions about the magnitude and timing of outcomes and costs for three 

alternative futures: one guided by the narrative rule, one under the NNC rule, and one under the 

proposed Florida rule. 

Costs Defined 

For the purposes of the new framework proposed in this section, three costs are defined 

as follows. 

 Nutrient load control costs are the capital, operation, maintenance, and replacement costs 

incurred by dischargers to implement any action to reduce the discharge of N or P into a 

waterbody. These were the principal costs considered in the EPA analysis. 

 Administrative costs are borne by public or private entities for ambient monitoring, 

assessment, developing plans (e.g., SSAC application and review, TMDL development, 

establishing a BMAP), permit issuance, permit compliance reporting and monitoring, 

negotiating and gaining agreement by landowners to implement BMPs, engaging in legal 

rules and challenges, etc. 

 Water quality opportunity costs are the forgone benefits from not improving water quality 

to some particular level (see Box 3-2). 
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Box 3-2 

Water Quality Benefits 

The committee was asked to review those analyses that reported on the costs of possible nutrient 

load reduction actions. Other parts of the EPA (2010) report, not included in the committee task 

statement, included estimates of the water quality benefits from adoption of the NNC rule. By implication, 

the broader analysis implies that failure to adopt the NNC rule would result in water quality benefits being 

forgone; these forgone benefits being a “water quality opportunity cost” of continuing with the narrative 

rule. This opportunity cost argument was made to the Committee in several letters and presentations by 

Florida-based and national NGOs. They asserted that it was inappropriate and perhaps misleading to 

review only incremental load reduction and administrative costs. The Committee did not review the EPA 

described benefits of the NNC rule. 

The continuing interest in this topic warranted the presentation in this chapter of the way to frame 

future analyses to accommodate these concerns. However, this is not a call for detailed water quality 

modeling for large and complex systems, followed by quantification of benefits (as was done in the EPA 

analysis). It is, rather, a recognition that a cost analysis will also need to report on assumptions about 

how different actions taken at different times are more or less likely to protect designated uses, with 

considerations to response lag times, legacy loads, and demographic and economic growth and change. 

Timing and Cost Uncertainty 

As discussed in the first section of this chapter, the three rules differentially affect the 

timing of the five stages of water quality management, and as a result, also the realization of 

administrative and load control costs and water quality outcomes. However, timing was not 

considered in the EPA and other reports. The EPA estimates the incremental cost of the NNC 

rule as the annualized present value of nutrient control costs to fully meet the numeric criteria for 

the incrementally impaired waters and for the incrementally affected point sources. No date is 

given when this level of implementation would be achieved, but the impression that is given is 

that these costs would be faced soon after implementation. 2 

In fact, timing was not considered even though the proposed NNC rule was explicitly 

described by EPA as a way to “increase the pace of listing,” with the implication that this would 

then accelerate the TMDL and implementation stages (King, 2011)3

, and despite the well 

understood reality that implementation under either narrative or numeric rules is constrained by 

the time required to conduct the necessary studies and by limited budgets and staff. Articulating 

when costs would be incurred and what level of implementation across the two rules can be 

expected would provide a more realistic and transparent means to compare the two rules in order 

to estimate the incremental costs and water quality outcomes. Furthermore, a more explicit and 

quantitative consideration of timing in the cost analyses would acknowledge that predictions of 

future conditions under various rules have to be made and that any such predictions is 

accompanied by substantial uncertainty. 

 

2

 Note that EPA’s guidance on conducting economic analysis (EPA, 2010a) discusses the need to identify both a 

start and end point for comparing baseline and alternative policy scenarios. 3

 The environmental NGO community has made a similar argument in letters to the Committee and in other public 

statements. 
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In general, predictions of administrative and load control costs over time, and the 

resulting water quality outcomes, depend on many assumptions including (1) regulatory agency 

behavior, (2) future political and legal decisions/interpretations, (3) watershed response to load 

reductions, (4) unit costs of currently known load reduction activities, (5) changes in cost and 

effectiveness of control technologies, and (6) socioeconomic, demographic and land use change. 

Uncertainty can be attributed to a lack of knowledge about the cost of relatively untried 

technologies or the level of implementation required to meet water quality criteria. Uncertainty 

can also arise because of unknown future economic conditions and how behavior may change 

when program rules and incentives change. For instance, substantial uncertainty exists on how 

the implementation of the numeric nutrient criteria will be translated into effluent limits for point 

sources. Many of these key uncertainties cannot be eliminated by more data collection or 

analysis. 

Of course, uncertainty does not need to be taken into account when making a water 

quality management decision if the future costs of being wrong are trivial. It is only when the 

future costs of a wrong decision are significant that uncertainty takes on relevance when making 

the initial decision, and demands that an analysis characterize and communicate those 

uncertainties. Analysts can characterize and communicate these decision relevant uncertainties 

(i.e. uncertainties that affect costs) in different ways. EPA’s analysis included some discussion 

of uncertainty about the assumptions used in its analysis. Cardno ENTRIX performed an 

uncertainty analysis on the level of treatment and unit costs, relying on a data-limited MonteCarlo simulation. A cost analysis framework that fully recognizes and incorporates timing and 

uncertainty is presented next. 

The Framework Description 

A cost analysis requires comparing the future time paths of costs at each stage under 

either the NNC rule or proposed Florida Rule to the narrative rule (the baseline). This means 

predicting of the level of activities at each stage for a series of future dates, under each rule, and 

in turn the timing of future costs. The analysis would be comprised of several tasks. 

Task 1. Predict the decisions that would be made in each stage, for each rule. The 

predictions would be for specified time intervals, such as for five-year increments. This 

prediction requires a clear understanding of the differences in the rules, as described in the 

beginning of this chapter. The differences among the three rules can lead to different decisions 

at each stage of water quality management including which waters are impaired; which waters 

are stressed by nutrients, and which nutrients are the stressors; at what level do the nutrients 

become a stressor and how this level gets reflected in the TMDL; what are the implementation 

actions for load reduction, when are the actions required, and what sectors bear the responsibility 

and costs for those actions; and when has the designated use been attained so that additional load 

controls are not needed. Prediction of these decisions requires making assumptions about both 

the likelihood of any particular decision, and the relationship of that decision to others that 

follow in sequence. These different assumptions about both the ways the rules will work in 

practice, as well as about the cost estimates for certain load control practices, are the source of 

the very different cost estimates found in the EPA report compared to the competing analyses. 

In addition, these same differences of view lead the environmental NGO community to assert 
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that the narrative rule and the proposed Florida rule will result in significant loss of water quality 

benefits. 

Task 2. Estimate administrative and load control costs under each rule and for each 

future time period. Chapter 2 provides a detailed review of the EPA estimate of unit costs and 

lengthy discussion of the effectiveness of the load control methods. In the broader framework, 

there should be at least a narrative statement of the predicted water quality outcomes at each 

point in time. 

Task 3. Characterize uncertainties in Tasks 1 and 2. Determine if the costs of uncertainty 

are likely to be high. If so, determine whether it is possible to assign probabilities to outcomes 

and compute expected values (and other moments of the cost distribution) or whether to conduct 

scenario analysis. Scenario analysis is a method for considering the importance of the most 

uncertain future conditions affecting an analytical outcome. Unlike single factor sensitivity 

analysis, scenario analysis requires describing different combinations of uncertain future 

conditions that taken together can create different outcomes. Building scenarios can help to 

isolate those combinations of possible future conditions that are most likely to have significant 

effects on (in this case) costs. Building scenarios can be a group activity that facilitates 

knowledge exchange and mutual understanding of central issues important to the results of the 

analysis. 

Task 4. Calculate the incremental difference in total costs (costs of the proposed NNC 

rule less costs of narrative rule) and relate this to the incremental differences in water quality 

outcomes at each time period. The costs for the existing narrative rule would serve as the 

baseline for any comparisons. 

Task 5. Record each result in a decision-making display. Figure 3-1 illustrates a 

template for a single set of assumptions. The rows in grey are decisions and actions at each stage 

in a rule and are identical to the rows in Table 3-1. There would be templates created for each 

set of assumptions for the narrative rule (the baseline) and then one for each set of assumptions 

under the alternative rule (here the NNC). 

The content of the grey shaded cells is a description of the level of administrative and 

load control effort and when the effort is predicted to occur. For example, the cells in each 

figure can be used to describe when and how many waterbodies would be listed (Stage 1) over a 

fixed time period. The metrics used for each stage [e.g., the number of waterbodies assessed and 

listed as impaired (Stage 1), metrics of the stressor evaluation (Stage 2), the number of TMDL 

plans developed (Stage 3), metrics of the implementation of plans (Stage 4), and the number of 

waterbodies meeting the designated use (Stage 5)] should be predicted and the prediction 

explained, based on how the rule governs these stages and the available funding. Costs are 

calculated by multiplying the load reduction effort (grey cells) by the cost per unit of effort. This 

is how the EPA analysis was completed, but unlike the EPA analysis, this framework would 

make explicit that costs will occur at different times under the two rules. 
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FIGURE 3-1 Timeline of Stages and Related Costs for a Rule Year 0 

Year 5 Year 10 Year 15 Year 20 Year 25 Year n 

Stage 1 List Waters as Impaired

Stage 2 Establish Stressor

Stage 3 Define Level of Nutrient 

Reduction/Write TMDL

Stage 4 Develop TMDL/BMAP Implementation 

Stage 5 Determine Use Attainment

 

Administrative Costs $___ $___ $___ $___ $___ $___ $__ 

Load Control Costs $___ $___ $___ $___ $___ $___ $__ 

Administrative plus Load Control Costs $___ $___ $___ $___ $___ $___ $__ 

Water quality outcomes 

 

The content of the cells, as well as the costs and outcomes, can be based on trend analysis 

of historical records, predictive models, statistical equations, and expert judgment. Once 

complete, the costs of the narrative process could be subtracted from the numeric process to get a 

total cost difference, which could be compared to the incremental differences in water quality 

outcomes and interpreted in light of the uncertainty of the total cost estimates of each process. 

This can be done for each time period and would provide information on the implication for 

annual public budgets and when water quality results might be realized. Of course the total cost 

of either rule can still be calculated as the difference in the present value of the annual total cost 

between the two rules.4

If uncertainty was not going to be considered in the analysis, then the grey cells simply 

would record what assumptions were made to warrant the costs shown. However, if there are 

different assumptions made, then the analysis described above would be repeated for each set of 

assumptions and cost estimates and water quality outcomes for the narrative process, and then 

for the NNC process and the array of different outcomes described. These different outcomes 

might be assigned a probability of occurrence and an expected value, or they may be left as 

individual scenarios (see Task 3). 

Most importantly, the framework encourages decision participants and analysts to 

explicitly discuss and test assumptions and transparently articulate the differences in costs that 

might result from these assumptions. For instance, the number of permits modified and 

stringency of controls within the permits over the period of analysis can be compared with and 

without the NNC rule. Such a comparison would clearly define what might occur under the 

 

4

 Also other outcomes of interest such as effects on employment could be made and reported in the same format. 
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baseline condition and transparently illustrate how the level and pace of activities would differ 

under an alternative rule and alternative assumptions. 

How to Use the Cost Estimation Framework 

This section offers illustrative examples of how an analyst might fill out the rows in the 

general framework described by Figure 3-1, for both the narrative (baseline) and the NNC rules. 

Because differences in the assumptions underlying how this might be done are often the source 

of disagreement, discussing how these tables are filled out can be an important means to clarify 

issues and create transparency in the evaluation of the various options. For exposition purposes, 

the proposed Florida rule is not included in this illustration. 

Illustration 1: The Incremental Difference in Nutrient-Stressed Waters 

This discussion illustrates how the incremental differences of the NNC rule at the end of 

Stage 3 can be described. Under the NNC rule EPA estimates that new waters would be listed 

(EPA, 2010b, p. 6-3) as nutrient impaired presumably almost immediately after the numeric 

nutrient criteria rule is adopted. However, it also is reasonable to assume that additional waters 

would be listed as nutrient impaired under the NNC rule in future years, since more than half of 

all waters could not be assessed due to insufficient data (note that EPA assumed no additional 

waters would be listed under the NNC rule beyond the initial assessment). An example of the 

time path of the number of nutrient-impaired waters listed (at the end of Stage 2) under the NNC 

rule is shown graphically by the blue line in Figure 3-2. The dashed lines indicate uncertainty 

bands on the estimate of new waters listed under the NNC rule. 

Absent the implementation of the NNC rule, additional waters would also have been 

listed as biologically impaired under the narrative rule (in Stage 1), deemed to be stressed by 

nutrients (in Stage 2) and then assigned nutrient targets (in Stage 3). The total number of new 

waters deemed stressed by nutrients in the future under the narrative rule can also be estimated, 

as shown by the black line in Figure 3-2 (with associated uncertainty bars). The black line shows 

that a number of waters assessed and identified as stressed by nutrients will steadily be added to 

the impaired waters list under the narrative standard. FDEP conducts a number of WBID 

assessments each year and adds biologically impaired waters that are deemed nutrient stressed to 

its 303(d) impaired waters listed annually. Projecting this historical pace into the future, the 

number of new waterbodies assessed, listed, and identified as nutrient stressed under the existing 

Florida narrative rule could be estimated. 

The incremental effect of the NNC rule on Stages 1-3 is the difference between the blue 

and black lines over time (see Figure 3-2). Because EPA’s analysis did not evaluate an 

implementation time path, EPA effectively assumed that the only incremental change was the 

initial new listing of waters (the difference between the blue line and black lines at a single point 

in time). 
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FIGURE 3-2 Illustration of Incrementally Listed Waters 

A more complete analysis also would recognize that the narrative rule may list different 

waterbodies than the NNC rule and ultimately the narrative may require different nutrient targets 

than the numeric nutrient criteria. Conceptually more waters could be deemed nutrient stressed 

under the narrative rule at the end of the evaluation period if the NNC rule misses waters that are 

biologically impaired. Conversely, the NNC rule may deem more waters as nutrient stressed at 

the end of the evaluation period if the NNC rule includes waters that are not biologically 

impaired, or if the resource intensive, but budget constrained, narrative rule moves at a slow 

pace. These and other possibilities are the basis for creating the uncertainty bands. Assumptions 

and analysis regarding the different possible outcomes produced by the two rules will ultimately 

have consequences on estimates of nutrient control costs that will be incurred. 

Illustration 2: Administrative Costs for Listing and Stressor Assessment 

As described above, the two rules entail a number of activities, each requiring a resource 

commitment to assess and perhaps re-assess waters for possible nutrient impairments. These 

costs were not estimated in the EPA analysis, but as described above represent important 

differences between the two rules. These differences in turn, will generate incremental 

administrative cost differences between the narrative rule and proposed alternatives. 

An illustrative example of the possible relative magnitude and time path of some 

administrative costs incurred by the narrative and NNC rules is shown in Figure 3-3. Two 

administrative costs are shown, one representing the cost of listing waters as impaired and the 

possible administrative costs of an SSAC rule. In each illustrative graph, the time path of annual 

administrative costs under the narrative rule is show in black while the time path of costs under 

Incrementally

stressed 

WBIDs 

 time in years 

# WBIDs 

stressed by 

nutrients 

NNC

Narrative
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A B 

FIGURE 3-3 Illustration of Select Administrative Costs. 

the NNC rule is shown in blue (the difference between the two represents the incremental cost of 

the proposed NNC rule). 

Figure 3-3(A) shows the timing and uncertainty of possible future listing administrative 

costs under the narrative rule and NNC rule. The narrative rule requires a substantial 

commitment of staff and monitoring resources to identify waters of potential concern, biological 

monitoring, and stressor-response analysis to identify the cause of the biological impairment. 

Over time, the annual cost of listing activities may be fairly stable, but could increase or decrease 

over time (as shown by the uncertainty bands). The NNC rule avoids many of these costs and 

accelerates the determination of whether a waterbody is to be listed as nutrient impaired. The 

cost of making that determination is limited to the cost of chemical water quality monitoring and 

determined through a predefined sampling procedure. While the magnitude and direction of 

these listing costs under the NNC rule is uncertain, the relevant point is that it is reasonable to 

conclude that the NNC rule would produce a net incremental cost savings in the administrative 

costs associated with the listing (difference between two cost time paths). 

The NNC rule allows numeric criteria to be adjusted to take site-specific conditions into 

account through an SSAC rule. Public and private costs, including administrative, analytical, 

and legal costs, would be incurred for the SSAC and need to be considered as a part of a cost 

analysis of the NNC rule. The SSAC cost would represent a potentially significant, but highly 

uncertain, new cost borne by those who would be expected to petition for an SSAC. Figure 3-

3(B) illustrates what SSAC costs could be under the assumption that petitioners will challenge a 

portion of a large increase in newly listed waters under the NNC rule (solid blue line). SSAC 

administrative costs could then gradually decrease as the number of cases declines. By 

comparison, SSAC costs are modest under the narrative rule (black line). Also, as has been 

noted elsewhere, SSAC costs may also be incurred for waters already listed as impaired under 

time in years time in years 

Narrative

$

Nutrient Listing Costs 

NNC

Narrative NNC

SSAC Administrative Costs 

$
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the narrative standard. Possible legal challenges for the existing TMDLs could also potentially 

escalate SSAC administrative costs further. 

The uncertainty bands surrounding SSAC costs under the NNC process are shown as 

large (especially the upper bound) because of higher type I (over-control) error rates under the 

NNC and the highly contentious nature of water policy in Florida, which might inflate legal and 

administrative costs of conducting SSACs.5 On the other hand, the administrative costs incurred 

in the SSAC rule might be low because either type I errors are low or the barriers to SSAC 

participation are so high that petitioners avoid the rule entirely.6 Regardless, this discussion 

illustrates that the NNC rule potentially creates significant new SSAC-related administrative 

costs. 

EPA did not include costs for the SSAC process in its analysis, because it asserted that 

the SSAC-like costs associated with site-specific biological assessments are similar to those 

undertaken under the narrative rule [in other words, the higher costs in Figure 3-3(B) offset the 

lower costs in Figure 3-3(A)]. However, there are various legitimate reasons to believe this will 

not be the case. Given the untested nature of the SSAC rule, it is not clear that the total SSAC 

and administrative listing costs would ever be the same, yet it is certain that the party that would 

bear the costs is different. 

Illustration 3: Timing of Municipal and Industrial Permits and Nutrient Control Costs 

Chapter 2 reviewed the estimation of nutrient control costs and uncertainties for 

municipal and industrial wastewater plants with NPDES permits. This analysis builds on the 

previous chapter by highlighting the substantial cost differences between the narrative and NNC 

rule related to the timing of point source control costs. The general pattern of the timing of 

permit modification and future compliance costs under the NNC and narrative rules is shown in 

Figure 3-4. According to EPA’s assumptions, all industrial and municipal point without 

sufficiently stringent nutrient limits would face new nutrient effluent limits in their permits under 

the NNC rule. Presumably, these permits would be modified within five years of adopting the 

NNC rule and implemented independently of a TMDL. Thus, the point source control costs 

would also be incurred soon after the NNC rule is adopted, with a WQBEL being set possibly at 

the level of the numeric nutrient criteria. Under the narrative rule, some point source permits 

would also be incrementally tightened, but this would occur gradually as TMDL plans are 

developed and implemented in watersheds with these point sources. The number of future 

permit modifications under the narrative rule could be estimated by obtaining the historical 

pattern of permit modifications. Figure 3-4(A) suggests that point sources would likely bear the 

brunt of cost increases in the initial stages of NNC Rule implementation. 

The difference in point source control costs between the narrative and NNC rules is a 

function of the rate of permit modifications and differences in unit costs. Cost differences are 

magnified further when considering that the two rules will likely produce different levels of 

 

5

 Similarly, administrative SSAC costs could be higher if the N or P targets in the existing TMDLs are not accepted 

as SSACs. If the TMDLs are not accepted as SSACs then there will be additional administrative and control costs 

by either conducting a new SSAC or due to additional nutrient targets imposed by the NNC.

6

 Given high administrative barriers and high type 1 errors, the NNC process could potentially increase the control 

costs faced by the different source sectors (see below) by increasing the amount of area covered by a TMDL. 
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A B 

FIGURE 3-4: Illustration of the Timing and Uncertainty of Point Source Costs 

control requirements; that is, at Stages 4 and 5 there might be significant differences in which 

nutrients have targets for a given waterbody and by how the targets differ from the numeric 

nutrient criteria. As Chapter 2 highlights, the upper bound estimates of costs to meet the numeric 

nutrient criteria themselves in plant discharges could be very high [see upper bound dashed blue 

line on Figure 3-4(B)]. Point source costs would increase more slowly under the narrative 

standard both because permit requirements are phased in over time and effluent limits would be 

established under Florida TMDL and BMAP rules (which historically has not required end-ofpipe level controls). Arguably there is less cost uncertainty under the narrative rule than the 

proposed NNC rule. 

Illustration 4: Control Costs for Nonpoint Sources 

A stated objective of the NNC rule is to accelerate the implementation of nutrient 

controls (King, 2010). Assuming that sources outside the NPDES program dominate loadings, 

under either the narrative or numeric process the majority of nutrient control efforts will be 

initiated via TMDL development and BMAP implementation (Stage 4 in Figure 3-1). EPA 

estimated the incremental costs of developing TMDLs and BMAPs that would occur under the 

NNC rule with no implementation time frame given and with no consideration to what would 

have occurred in the absence of the proposed rule. 

If one considers the difference in costs across time, it is clear that the NNC process would 

create a larger number of listed waters immediately. However, conducting a TMDL analysis and 

developing a TMDL/BMAP plan are resource- and time-intensive, with the rate of 

implementation linked to the level of public cost share support for staff resources and the 

adoption of control practices. Faced with limited budgets, there already exists a backlog of listed 

Narrative

#

time in yrs 

# NPDES Permits Modified to 

Control for Nutrients 

NNC 

Narrative

Annual Point Source Nutrient 

Control Costs 

$

NNC

time in yrs 
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waters without an implementation plan. Currently, only a relatively small portion of all waters 

listed as nutrient impaired have completed a TMDL and even fewer are under an active BMAP 

(EPA, 2010b, p. 2-23). Based on past rates of implementation, waters that might be listed 

immediately under a numeric rule may require years to develop TMDLs and BMAPs. Thus, the 

pace of TMDL/BMAP development under both rules is expected to be similar and to gradually 

increase over time [see the black and blue lines in Figure 3-5(A)]. The time path of plan 

development is shown as slightly lower under the narrative process because TMDLs may be 

more analytically challenging due to having biological endpoints. Nonetheless, the relevant 

point is that the incremental difference between the two rules in terms of when and how many 

waters will be under an active BMAP plan is predicted to be relatively small due to the existing 

implementation bottleneck [difference between the blue and black lines in Figure 3-5(A)].

The cost implication of these constraints and limitations on the TMDL/BMAP 

implementation process is that the cost differences between the NNC and the narrative rules 

could be small. Figure 3-5(B) shows the differences in nonpoint source control costs of 

implementing actions to meet the numeric nutrient criteria relative to meeting the narrative 

targets. Under both rules, nonpoint source control costs will be incurred and these costs will 

likely increase over time as more expensive efforts are pursued to achieve the water quality 

criteria. Yet, the difference between the NNC and narrative nonpoint source control curves, 

which is the incremental cost of the proposed rule, is small, assuming the funding and staffing 

constraints will be similar across processes. 

Figure 3-5(B) also illustrates the substantial uncertainty associated with nonpoint source 

administrative and load control cost under either rule. Chapter 2 discussed the uncertainty 

surrounding nonpoint unit control costs for both agricultural and urban sources, as well as the 

level of application (number, type and effectiveness of BMPs) needed to achieve nutrient 

targets/criteria. However, these uncertainties exist under either future process and are arguably 

substantial. On the other hand, there are possible differences among rules that may lead to 

different costs for nonpoint sources. For example, the NNC rule requires the achievement of 

both nitrogen and phosphorus targets in a TMDL plan while the narrative standard may only 

target one nutrient. Achieving two targets will be more costly than achieving just one, thus 

increasing the incremental cost of the NNC rule (holding other factors constant). However, the 

stringency of the final nutrient limits that emerge in the TMDL process under the narrative 

process is itself uncertain. It is possible that more stringent nutrient requirements would be 

necessary to achieve biological criteria under the narrative rule (see Box 3-1), increasing the 

potential costs under the narrative and reducing or eliminating the cost differences between the 

two processes. What this suggests, and what is shown in Figure 3-5(B), is that the incremental

increase in nonpoint control costs is highly uncertain. 

Finally, such an analysis also clearly distinguishes between the incremental and the total 

cost of achieving nutrient standards. While the difference between nonpoint source control costs 

under the two rules can be analyzed and debated, it should be clear that the costs to reduce 

nonpoint source discharges to meet water quality standards under either rule are going to be high 

and the costs are only likely to increase over time if water quality criteria are to be achieved. 
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A B 

FIGURE 3-5: Illustration of the TMDL and NPS Control Costs Time Paths 

Illustration 5: Ambient Water Quality Outcomes 

A final illustration is provided regarding the pace of water quality outcomes under the 

narrative vs. the numeric process. In seeking to reduce the likelihood of type II error 

(undercontrol), the NNC rule accelerates both the pace of listing and the imposition of controls 

and costs for point sources. It is possible that reducing the delay in getting to the implementation 

stage under the NNC rule will reduce the risk of a loss of water quality benefits over the short or 

long term. That is, the NNC rule might be expected under some assumptions to result in 

incremental improvement in water quality outcomes and in more waterbodies meeting their 

designated uses at certain points in the future (see Figure 3-6). 

On the other hand, the discussion above indicates that because the NNC rule does not 

alter the regulatory and budgetary constraints on nonpoint source controls, the acceleration of 

water quality improvements that occurs over time could be modest. Furthermore, as Chapter 2 

points out, considerable uncertainty exists as to the extent and intensity of controls that will be 

necessary to achieve designated uses in impaired waters. This uncertainty has the potential to 

push achievement of water quality objectives further out into the future, such that the differences 

between the rates at which waters meet designated uses under the two rules might be modest or 

even nonexistent (see Figure 3-6). 

Narrative

NNC

Narrative

#

Time in yrs 

# BMAP Plans Developed 

Time in yrs 

Annual BMAP Implementation Costs 

$

NNC
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FIGURE 3-6: Progress toward Meeting the Designated Uses 

TRANSPARENCY AND DISPUTE RESOLUTION 

UNDER THE PROPOSED FRAMEWORK 

As has been emphasized, it is only when the future costs of a wrong decision are 

significant that analytical uncertainty is relevant to making a decision. In the water quality 

management context, one possible cost consequence of analytical error is that assessment 

decisions and subsequent control actions may lead to control of nutrients in places where 

nutrients were not the stressor or at levels that exceed those required to meet the designated use. 

If this was the result there would have been unnecessary load control costs placed on limited 

public budgets and on the financial viability of businesses. On the other hand, the argument 

offered by the environmental NGOs and supported by the EPA is that the narrative rule, in 

minimizing the possible error of over control of nutrients, makes water quality management too 

slow and inadequate in protecting designated uses. The dispute over the EPA cost analysis that 

was the reason for the formation of this Committee can be understood as a difference of 

viewpoints among agencies and stakeholders about the likelihood that different rules will lead to 

errors of over control or under control of nutrients and the cost consequences of those errors. 

The cost analysis framework presented in the previous section can help to narrow 

disagreements over the assumptions that might be made to accommodate uncertainty over unit 

costs, effectiveness of load control, water quality response, and rule design. Thus, a report to 

decision makers organized around the likelihood and costs of analytical error serves a different 

purpose than the role often played by a traditional benefit–cost analysis, as represented by the 

EPA report. In the EPA analysis the rule was written and proposed and then a benefit–cost 

analysis was conducted to determine the justification for the rule as written. This is a standard 

application of benefit–cost analysis that proposes to answer a single question: “Is the rule change 

justified, or is it not?” To answer this question, different analyses had to make different 

assumptions (implicit or explicit) about how the rule would be implemented over time. The 

uncertainties in those assumptions could be reported in some fashion, as EPA and Cardno 

ENTRIX attempted to do in different ways. However, simply reporting uncertainty over benefits 

and costs, when the question is framed only as whether a predefined rule change is justified, does 

not contribute to stakeholders’ appreciation of uncertainty nor does it help develop water quality 

time in years 

Index of WQ 

improvements 

NNC

Narrative 
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management processes to minimize the likelihood of both under-control and over-control of 

nutrients. 

The analytical framework proposed in this chapter could be used in support of rule design 

and could then be transformed to provide an analysis of the justification of any given design. In 

fact, Florida’s newly proposed alternative to the NNC rule remains focused on minimizing the 

possibility of load control cost error, although it seeks to address the criticism that the state has 

ignored the possibility of too little control on nutrients by having new listing and stressor 

assessment components during Stages 1 and 2. However, whether these modifications will 

achieve the desired result is unanalyzed, with the result that environmental NGOs are likely to 

oppose the new Florida rule. This is not to suggest that had EPA (and FDEP) followed the 

framework presented in this chapter that there would have been no opposition; however, it is the 

case that the analyses done to date have done little to bridge gaps that exist between 

stakeholders. Indeed, EPA conducted its cost analysis in a manner that led some Florida 

stakeholders to have concerns over its salience, legitimacy, and credibility (Jordan et al., 2011; 

Maguire, 2003). 

The following are examples of different ways that reaching agreement on how the water 

quality management process would change under the various rules might have reduced 

differences in assumptions and narrowed the estimated cost differences: 

 Increases in administrative budgets for assessment and monitoring could reduce the 

expected size of, and concern over, the costs of both type I and II errors (Shabman 

and Smith, 2003; NRC, 2001). 

 The uncertainty about the SSAC guidelines led to wholly different assumptions by 

different stakeholder groups. Greater clarity and understanding about the SSAC 

process, which is central to the NNC rule, might lead to less divergence in 

assumptions about the cost of applying for SSAC and the likelihood of SSAC 

approval. 

 There were different assumptions made regarding whether the numeric nutrient 

criteria would become WQBELs for NPDES permitted sources, with the EPA cost 

analysis assuming less stringent levels of control and being silent on when they would 

be imposed on NPDES regulated sources. Greater clarity and understanding of the 

way in which the NNC rule would affect NPDES permit limits might lead to less 

divergence in assumptions made about the resulting WQBELs. 

 The implied assumptions in all analyses were that the TMDL and BMAP once set in 

motion by the NNC rule could not be altered by new information on costs, 

effectiveness, and water quality response. A more explicit inclusion of principles of 

adaptive implementation, and an associated budget commitment, may have lessened 

concerns about the costs type I and II errors (NRC, 2001; Shabman et al., 2007). 

In the end, the “cost” of error depends on what a decision maker believes about the 

likelihood of an effect of the rule change and their own judgment about the future severity of the 

adverse consequences. Analysis can narrow, but not eliminate, differences of view about the 

uncertainty surrounding these two determinants of costs. Some stakeholders will have 

preferences that make them unwilling to accept the possibility of costs of over-control, while 

others will not accept a rule that they believe will bring about a possible loss of water quality 

benefits. Analysis cannot bridge such gaps in preferences. 
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FINDINGS

FINDING: The incremental costs of the NNC rule are attributable to more than an increase in 

waterbodies listed and a requirement that all NPDES-permitted municipal and industrial sources 

discharging to surface water have certain effluent concentration limits. In computing the 

incremental effect, the appropriate baseline should have been defined as what would have 

occurred over time under the existing (narrative) rule. Thus, an incremental cost is the difference 

in implementation costs between two (or more) alternative future implementation time paths. 

 Future cost analyses of rule changes would more fully represent areas of possible costs 

differences (administration, load control, and water quality opportunity costs) if they were more 

explicit in describing the differences between the rules over time. This could be done by 

analyzing and reporting costs as a cash flow over time, showing what sectors bear the costs as 

nutrient load reductions at different levels are pursued. Comparing the rules over time also can 

provide an opportunity to present a realistic picture of how the timing of water quality 

improvement actions might unfold with alternative rules, by illustrating the time lags between 

listing and achievement of water quality standards. Most importantly, reporting on timing would 

provide useful information for predicting annual budgetary requirements. 

FINDING: Uncertainty is pervasive in estimating the incremental cost of implementing the NNC 

rule and is inadequately represented in the EPA analysis. In future analyses, reporting the 

difference in the time paths for implementation of water quality management rules, and 

associated uncertainties, would provide a more transparent and realistic way to compare costs of 

the different rules and provide more useful information about where, when, and how costs 

diverge. 

FINDING: Some stakeholders viewed the EPA cost analysis as being superficial or of limited 

scope, leading to reduced credibility. The result was to foster disagreement about embedded 

assumptions rather than use the analysis to isolate and possibly reconcile sources of 

disagreement. Cost analysis as outlined in this chapter can help convey cost estimates in a more 

transparent way and thus facilitate learning, reduce misunderstandings among stakeholders, and 

increase public confidence in the results. 

FINDING: Based on the conceptual reviews in this chapter and on the content of Chapter 2, the 

following broad findings are made about the differences between the NNC and narrative rules: 

 Administrative costs for listing and TMDL development for FDEP will be lower under 

the NNC rule because there would be no biological assessment (unless FDEP is the 

SSAC petitioner). In part, this administrative cost reduction is made possible by the 

NNC rule shifting the responsibility for SSAC-like analyses to SSAC petitioners and 

away from the FDEP. 

 Compared to the narrative rule, under the NNC rule the pace of listing and the number of 

waters listed will increase, but the rate at which TMDLs and BMAPs are developed and 

load controls implemented to meet the designated use will not necessarily increase.

 Municipal and industrial wastewater dischargers may face substantial near-term increases 

in cost under the NNC rule. 

 Over time, there is significant uncertainty in nonpoint source load control costs under 

either rule because of uncertainty about the incremental increase in the number of listed 
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waters, about the nutrient target levels for N or P, and about cost and effectiveness of 

nonpoint source load control actions. 

FINDING: Conducting the cost analysis as outlined in this chapter, with increased attention to 

careful assessment of rule differences, stakeholder engagement, and uncertainty analysis, might 

not have been possible with the budget and time EPA spent on its cost analysis. Any critique of 

the existing EPA cost analysis should recognize that some deficiencies may be traced to time and 

budget limitations. 

REFERENCES 

FDEP. 2001. A Report to the Governor and the Legislature on the Allocation of Total 

Maximum Daily Loads in Florida. 

Jordan, N. R., C. Shively Slotterback, K. V. Cadieux, D. J. Mulla, D. G. Pitt, L. Schmitt Olabisi, 

J. Kim. 2011. TMDL implementation in agricultural landscapes: A communicative and 

systemic approach. Environ. Management. 48(1):1-12. 

King, E. 2011. Presentation to the NRC Committee. July 25, 2011 Orlando, FL. 

Maguire, L. A. 2003. Interplay of Science and Stakeholder Values in Neuse River Total 

Maximum Daily Load Process. Journal of Water Resources Planning and Management 

129(4):261-270. 

National Research Council (NRC). 2001. Assessing the TMDL Approach to Water Quality 

Management. Washington, DC: National Academies Press. 

Shabman, L., and E. Smith. 2003. Implications of Applying Statistically Based Procedures for 

Water Quality Assessment. Journal of Water Resources Planning and Management 

129(4):330-336. 

Shabman, et al. 2007. Adaptive Implementation of Water Quality Improvement Plans: 

Opportunities and Challenges. Durham, NC: Duke University Nicholas School of the 

Environment and Earth Sciences. 

U.S. Environmental Protection Agency (EPA). 2010a. Guidelines for Preparing Economic 

Analyses. Washington, DC: EPA National Center for Environmental Economics, Office 

of Policy. 

U.S. EPA. 2010b. Economic Analysis of Final Water Quality Standards for Nutrients in Lakes 

and Flowing Waters in Florida. Environmental Protection Agency; November, 2010. 

U.S. EPA. 2011. Technical Assistance for Developing Nutrient Site-Specific Alternative 

Criteria in Florida. June 2011. Interim Draft. 
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Acronyms

AWT advanced wastewater treatment 

BMAP Basin Management Action Plan 

BMP best management practice 

CAFO concentrated animal feeding operation 

CWA Clean Water Act 

DO dissolved oxygen 

DPV downstream protection value 

EPA Environmental Protection Agency 

FDACS Florida Department of Agriculture and Consumer Services 

FDEP Florida Department of Environmental Protection 

FDOH Florida Department of Health 

FWEAUC Florida Water Environment Association Utility Council 

FWRA Florida Watershed Restoration Act 

GIS geographic information system 

HUC hydrologic unit code 

IWR Impaired Waters Rule 

LA load allocation 

MF microfiltration 

MGD million gallons per day 

MLE Modified Ludzack-Ettinger 

MOS margin of safety 

MOU memorandum of understanding 

NGO nongovernmental organization 

NNC numeric nutrient criteria 

NOI notice of intent 

NPDES National Pollutant Discharge Elimination System 

NRCS Natural Resources Conservation Service 

OIG Office of Inspector General 

O&M operation and maintenance 

OSTDS onsite sewage treatment and disposal systems 

PRB permeable reactive barrier 

RO reverse osmosis 

SCM stormwater control measure 

SIC Standard Industrial Classification 

SSAC site specific alternative criteria 
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SW surface water 

SWIM Surface Water Improvement and Management Act 

TMDL Total Maximum Daily Load 

TN total nitrogen 

TP total phosphorus 

TRAP Technical Review Advisory Panel 

UCT University of Cape Town 

USDA U.S. Department of Agriculture 

WBID Waterbody Identification Number1

WLA waste load allocation 

WQBEL water quality-based effluent limit 

WWTP wastewater treatment plants 

 

1

 WBID is used colloquially to refer to certain impaired waters, but technically the term also includes the 

surrounding drainage basin. 
105 

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Appendix A 

Narrative, Numeric, and Proposed Florida 

Nutrient Criteria Processes Illustrated 

Figures A-1, A-2, and A-3 at the end of this Appendix describe the narrative, numeric, 

and proposed Florida nutrient criteria processes, respectively. The Committee was unable to find 

similar flow diagrams developed by either EPA or FDEP, so the diagrams were developed 

internally as a means to better understand the differences in the processes. The Committee does 

not contend that these diagrams precisely illustrate the manner in which EPA or FDEP would 

implement any of the three processes. Rather, the diagrams were developed at a level of detail 

sufficient to compare key steps in the processes and understand the sequence and timing of 

events necessary to implement nutrient criteria under each. 

In each of the figures, common flow charting symbols are 

used. Rectangles represent processes, diamonds represent binary 

decision points (yes or no), while ovals represent terminal points 

in the process – a beginning or an ending. Circles and pentagons 

transfer the reader to other points in the processes where the next 

sequential step occurs if it does not directly follow the previous 

step in the overall process. 

Figures A-1, A-2, and A-3 all reflect the continuing assessment process expected under 

the Clean Water Act (CWA). They begin with the identification and assessment of a waterbody. 

If that water is listed as impaired, steps follow leading to the development of a TMDL for the 

stressor; implementation of actions to reduce the pollutant loading (the basin management action 

plan or BMAP as required under Florida law); and finally a process to ascertain when the 

designated use is met (delisting in the CWA process). Beyond this general similarity, however, 

there are significant differences in the sequence of actions that occur in the three processes and 

what is assumed about the activities and the decisions encountered in each. These differences in 

assumptions can lead to differences in cost estimates. 

In the current Florida narrative process (Figure A-1), it is apparent the process has 

additional steps for determining impairment compared to the EPA numeric nutrient criteria 

process (Figure A-2). First, the narrative process requires impairment identification for the 

narrative nutrient criteria – an imbalance of flora and fauna as determined by surrogate 

indicators. Once a determination is made regarding whether sufficient data exist and whether the 

data point to nutrients as a stressor, then the water is listed as impaired, a TMDL developed, and 

load reduction implemented through a BMAP. By contrast, the EPA numeric process (Figure A2) simply determines impairment based on whether the N and P criteria are exceeded in ambient 

waters. If so, and if site-specific alternative criteria (SSAC) have not been developed, the water 

is listed as impaired and a TMDL developed and implemented. 
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In both processes, waters are determined to return to compliance and removed from the 

impaired waters list if the ambient water quality criteria are met. In the case of the narrative 

process, the water is removed once the water supports its biological use, while in the numeric 

process the waters are removed if the N and P criteria are met. The processes then begin another 

iteration of evaluating the waters for compliance with either the narrative or numeric criteria. 

The proposed Florida process (Figure A-3) is significantly more complex than either the 

current narrative or EPA numeric nutrient criteria processes. The proposed process first 

ascertains if SSACs or TMDLs have been approved for a given waterbody. If a TMDL has 

already been developed, the process jumps forward to TMDL implementation or the BMAP 

process. If a TMDL has not been developed, but an SSAC has been approved, the waterbody is 

assessed against the SSAC. If an SSAC has not been approved, the waterbody is evaluated 

against “numeric interpretations of narrative nutrient criteria” (interpretations) and numeric 

nutrient thresholds. The thresholds are similar to numeric nutrient criteria in that numeric values 

are established for N and P. The main difference is that a failure of a threshold begins a process 

of additional study to see if biological impairments are manifested in the waterbody. If not, the 

waterbody is not deemed as impaired. If there is a biological impairment signal, the water is 

listed as impaired, a TMDL developed, and a BMAP developed and implemented. 

Additionally, waters can be identified as impaired if there is an adverse trend in nutrients 

or nutrient indicators. In other words, if long-term data show a decline in water quality as 

evidenced by an adverse trend in either nutrient or nutrient indicator monitoring data, the water is 

studied further. If modeling indicates the adverse trend will result in a waterbody impairment 

within five years, the water is listed as impaired, a TMDL developed, and a BMAP developed 

and implemented. 

Once a TMDL is triggered in the proposed process, the steps taken from that point on are 

essentially the same as the current narrative process. A TMDL will be developed and plan to 

implement the TMDL will be developed through the BMAP process. 

As described in Chapter 3 of the report, both the narrative process and the proposed 

Florida process opt to minimize Type I error – listing a waterbody as impaired that is not truly 

impaired. Therefore, more study is required to identify biological impairments and to identify 

nutrients as stressors for the impairment. This additional study necessarily results in added time 

required to reach the TMDL stage in the overall process. The EPA numeric process opts to 

minimize Type II error – not listing a waterbody as impaired that is truly impaired. That practice 

moves more quickly to the TMDL stage of the process, but there is no apparent increase in the 

speed at which TMDLs will be developed and implemented. 

Links to additional information on the three processes can be found as follow: 

I. The current Florida narrative nutrient criteria process 

 A. General historical information 

 http://www.dep.state.fl.us/water/wqssp/nutrients/

 B. Rule 62-302 – Surface Water Quality Standards 

 http://www.dep.state.fl.us/legal/Rules/shared/62-302/62-302.pdf

 C. Rule 62-303 - Identification of Impaired Surface Waters 

 http://www.dep.state.fl.us/legal/Rules/shared/62-303/62-303.pdf

II. The EPA numeric nutrient criteria process 

 A. General historical information 

http://edocket.access.gpo.gov/2010/2010-29943.htm

B. EPA final rule adopting the Florida numeric nutrient criteria 
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http://water.epa.gov/lawsregs/rulesregs/florida_index.cfm 

III. The proposed Florida nutrient criteria process 

 A. General historical information 

 http://www.dep.state.fl.us/water/wqssp/nutrients/

 B. Proposed Rule 62-302 – Surface Water Quality Standards 

 http://www.dep.state.fl.us/water/wqssp/nutrients/docs/meetings/62_302_final.pdf

C. Proposed Rule 62-303 - Identification of Impaired Surface Waters 

 http://www.dep.state.fl.us/water/wqssp/nutrients/docs/meetings/62_303_final.pdf
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Assess Imbalanced Flora and

Fauna by Biological Condition

Indices (BCI)

Lakes - TSI (Trophic State

Index)

Streams - Chlorophyll-a, or

algal mat presence

Springs - Nuisance algae

2

Ambient BCI

Attained?

4

Water is not

impaired

15

Water Body, Region, and Type

1

No

303d Verified

List

5

Establish TMDL

Targets for N

and/or P

10

Implement

N and/or P

reductions

13

TMDL Target Met?

14

Yes

303d Planning

List

3a

No

No

Initiate TMDL

Development

6

Sufficient Data?

3

No

N and/or P a

Stressor?

9

Yes

ID Stressor

7

Stressor ID’d?

8

Yes

Establish

TMDL for the

ID’s Stressor

10a

Implement

stressor

reductions

12a

TMDL Target Met?

13a

Yes

No

No

Acquire Sufficient

Data

3b

Yes

Yes

Develop Basin

Management

Action Plan

 (BMAP) 11a

Develop NPS

Implementation Based

LA

12b

Develop N and/or P

NPDES Permit

Limits Based on

WLA

12a

Develop Basin

Management

Action Plan

 (BMAP) 11a
Appendix A 109

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Determine NNC

(reference

method)

2

Assess Ambient

Nutrient Stream

Concn

5

Ambient Concn>

Crit?

6

Water is not impaired

10

Water Body, Region, and Type

1

Establish

TMDL for N

and/or P

9

De-list

9e

 SSAC?

7

Yes No

Yes

SSAC

Approved?

7b

No

Develop and

Submit SSAC

Proposal

7a

Assess Ambient

Nutrient Stream

Concn.

7c

Ambient Concn

< SSAC?

7d

Determine DPV

2a

Select Most

Stringent

3

Yes

Yes

No

No

303d Listed

for N and/or P

8

Develop TMDL

Implementation

Plan for N and/or

P

9a

Implement

N and/or P

reductions

9b

Ambient Concn<

Crit?

9d

No

Yes

Assess Ambient

Nutrient Stream

Concn.

9c

1

 SSAC?

9f

No

1

Yes

1 = Reference to a process

elsewhere on the page

Develop

NPDES Permt

w/N & P Limits

4
110 Review of the EPA’s Economic Analysis of Final Water Qu

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Place on

Planning List

5

 Fail Biological Health

Assessment (BHA) or Nutrient

Impairment (NI) Thresholds?

4

Place on

Study List

5a

Evidence of WQS

Nonattainment, But Insufficient

Information on Causative

Pollutant?

4a

Yes

No

Water Body is Confirmed to

be Biologically Impaired?

6

Yes

Nutrient is Causative

Pollutant?

7

Yes

No

No

No

Yes

Nutrient is Causative

Pollutant?

6a

Increasing Pollutant

Trend w/Impairment

Expected w/in 10 yr?

4b

Yes

No

Yes 

Go to TM

Developm

9

Assess Biological Health,Nutrient Impairment Thresholds,SSAC and Nutrient Trend*

3

Water Body, Region, and Type

1

No

TMDL Loads or Yes

Concns. Developed?

2b

No SSAC No

 Developed?

2

Yes

Develop SSAC?

2a

Yes

No

No

Go to BMAP

Development

2c 

* See no

Place o

Verified 
Appendix A 

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Establish TMDL

Targets for N

and/or P

12

Implement

N and/or P

reductions

15

TMDL Target Met?

16

Yes

Initiate TMDL

Development

11

Develop NPS

Implementation Based

LA

14b

Develop N and/or P

NPDES Permit

Limits Based on

WLA

14a

From Page

1, Step 9

10

Develop Basin

Management

Action Plan

 (BMAP) 13

To Step 1,

Pg. 1

17

No

Notes: Biological Health Assessme

Interpretation of Narrative 

I. Biological Health Assessment = Stream 

Lake Vegetation Index (LVI), or ShannoIndex.

II. Numeric Interpretations of Narrative 

A. Lakes = chlorophyll aB. Spring Vents = 0.35 mg/L of nitratC. Streams = chlorophyll a levels, alg

nuisance macrophyte growth, or ccomposition indicating imbalanceeither:1. SCI exceeded2. Nutrient thresholds exceeded

D. Estuary = site-specific numeric int

BMAP Developed?

11a

No

Yes

From Page

1, Step 2c

10a
112 

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Appendix B 

Biographical Sketches of Committee Members and Staff 

Glen T. Daigger (National Academy of Engineering), Chair, is senior vice president with 

CH2M HILL in Englewood, Colorado. He serves as Chief Wastewater Process Engineer and is 

responsible for wastewater process engineering on both municipal and industrial wastewater 

treatment projects on a firmwide basis. Dr. Daigger is the first Technical Fellow for the firm, an 

honor which recognizes the leadership he provides for CH2M HILL and for the profession in 

development and implementation of new wastewater treatment technology. He is also the Chief 

Technology Officer for the firm’s Civil Infrastructure Client Group, which includes the firm’s 

water, transportation, and operations businesses. F rom 1994-1996, Dr. Daigger served as 

Professor and Chair of the Department of Environmental Systems Engineering at Clemson 

University. Dr. Daigger is a registered professional engineer in the states of Indiana and 

Arizona, and a board certified environmental engineer. Dr. Daigger received his B.Sc.E. degree, 

his M.S.C.E. degree, and his Ph.D. degree, all in environmental engineering, from Purdue 

University. 

Otto C. Doering, Vice Chair, is a professor in the department of agricultural economics at 

Purdue University. He is a public policy specialist and has served the U.S. Department of 

Agriculture working on the 1977 and 1990 Farm Bills. In 1997, he was the Principal Advisor to 

USDA’s Natural Resources Conservation Service for implementing the 1996 Farm Bill. In 

1999, he was team leader for the economic analysis of the White House’s National Hypoxia 

Assessment. Dr. Doering has overseas experience with the Ford Foundation and the National 

Academy of Sciences, primarily in Southeast Asia. He has been a Director of the American 

Agricultural Economics Association and Chairman of the National Public Policy Education 

Committee. He twice has received the AAEA’s Distinguished Policy Contribution Award, as 

well as its Extension Economics Teaching Award. His recent publications have focused on 

economic linkages driving the responses to nitrogen over-enrichment, rationale of U. S. 

agricultural policy, and integrating biomass energy into existing energy systems. He served on 

the NRC Committee on the Mississippi River and the Clean Water Act. Dr. Doering received his 

M.S. degree in economics from the London School of Economics and his Ph.D. degree from 

Cornell University. 

Leonard A. Shabman, Vice Chair, joined Resources for the Future in 2002 as a resident scholar 

after three decades on the faculty at Virginia Tech. His research and communications efforts are 

focused on programs and responsibilities for flood and coastal storm risk management, design of 

payment for ecosystem services programs, and development of evaluation protocols for 

ecosystem restoration and management projects, with special focus on the Everglades, Coastal 
Appendix B 113 

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Louisiana and Chesapeake Bay. Among the specific topics related to these broader themes is 

applied research on permitting under Section 404 of the Clean Water Act, creating market-based 

incentives for water quality management and provision of ecosystem services, and design of 

collaborative water management institutions. He served for eight years on the National Research 

Council's Water Science and Technology Board, has chaired or been a member of several NRC 

committees and has been recognized as an Associate of the National Academy of Sciences. 

Walter L. Baker is the director of the Division of Water Quality (DWQ) for the State of Utah, 

where he has worked for the past 26 years. He currently serves as the Vice-President of the 

Association of State and Interstate Water Pollution Control Administrators; as Chair of the Water 

Quality Committee of the Western States Water Council; as a member of the Utah Lake 

Commission; as a member of the Utah Soil Conservation Commission; and as the Executive 

Secretary of the Utah Water Quality Board. Mr. Baker is a licensed professional engineer and a 

graduate of Utah State University. 

Allen P. Davis is a professor in the Department of Civil and Environmental Engineering at the 

University of Maryland. Dr. Davis' research interests are in aquatic environmental chemistry. 

He has been working on various issues related to urban storm water quality and the concept of 

low impact development (LID). Dr. Davis received the 2010 A. James Clark School of 

Engineering Faculty Outstanding Research Award, recognizing influential research 

accomplishments related to urban storm water quality, its management, and the LID concept. 

From 2001-2010, Dr. Davis served as the director of the Maryland Water Resources Research 

Center. He also has served as associate editor of Chemosphere, Science for Environmental 

Technology (2004-2010). Dr. Davis is a recipient of the National Science Foundation Young 

Investigator Award. He teaches courses in engineering sustainability, environmental process 

dynamics, and environmental engineering unit operations. He received his B.S. degree, his 

M.C.E. degree, and his Ph.D. degree from the University of Delaware. 

K. William Easter is a professor of applied economics and has been on the faculty of the 

University of Minnesota since 1970. One of his positions at Minnesota was serving as Director 

of the Center for International Food and Agricultural Policy (1999-2003). His research interests 

include resource economics, economic development and environmental economics, with a focus 

on water and land problems and resource pricing issues. Dr. Easter received his B.S. and M.S. 

degrees from the University of California-Davis and his Ph.D. degree at Michigan State 

University. 

Wendy D. Graham is the Carl S. Swisher Eminent Scholar in Water Resources in the 

Department of Agricultural and Biological Engineering at the University of Florida and director 

of the University of Florida Water Institute. Her research is focused on coupled hydrologicwater quality-ecosystem modeling; water resources evaluation and remediation; evaluation of 

impacts of agricultural production on surface- and groundwater quality; and development of 

hydrologic indicators of ecosystem status. She has previous NRC committee experience, having 

served on the Committee on Seeing Into the Earth: Non-Invasive Techniques for 

Characterization of the Shallow Subsurface for Environmental Engineering Applications, and as 

a member of the third Committee on Independent Scientific Review of Everglades Restoration 

Progress. Dr. Graham received her B.S.E. degree in environmental engineering from the 
114 Review of the EPA’s Economic Analysis of Final Water Quality Standards in Florida 

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University of Florida and her Ph.D. degree in civil engineering from the Massachusetts Institute 

of Technology. 

Arturo A. Keller is professor of biogeochemistry at the Bren School at the University of 

California, Santa Barbara. He holds a joint appointment in Mechanical and Environmental 

Engineering at UCSB. His research and teaching interests focus on water quality management 

and the fate and transport of pollutants in the environment. Dr. Keller also was the facilitator for 

the award-winning Nitrogen TMDL process for the Santa Clara River. He is also well-known 

for his expertise in the fate and transport of pollutants, including nanoparticles, organic liquids 

(NAPLs), and persistent organic pollutants associated with clay particles. Dr. Keller received a 

B.A. degree in chemistry and a B.S. degree in chemical engineering from Cornell University, an 

M.S. degree in civil engineering from Stanford University, and a Ph.D. degree in civil 

engineering from Stanford University. 

David J. Mulla is professor and the W. E. Larson Chair for Soil and Water Resources in the 

Department of Soil, Water, and Climate at the University of Minnesota. He is also the director 

of the university’s Precision Agriculture Center. Dr. Mulla’s research covers a wide variety of 

topics regarding agriculture, soil erosion, and water quality, including: (1) nonpoint source 

surface water pollution and watershed management, (2) transport and modeling of water, solutes, 

trace metals, and organic chemicals in soil, surface and groundwater, (3) impacts of biofuel and 

alternative crop production systems, (4) measurement, modeling, and management of soil 

erosion, (5) phosphorus and nitrogen transport in soils, (6) agricultural best management 

practices, (7) soil, landscape, and terrain modeling for precision conservation, and (8) field-scale 

variability for precision farming. In 2007 he was appointed a Founding Fellow in the University 

of Minnesota’s Institute on Environment. Dr. Mulla received his B.S. degree in Earth Sciences 

(with emphasis in geophysics) from the University of California at Riverside, and his M.S. and 

Ph.D. degrees in agronomy (emphasis in soil chemistry and physics) from Purdue University. 

Kevin M. Sherman is the Director of Engineering at Quanics, Inc. in Campellsburg, Kentucky. 

Dr. Sherman has 24 years experience working as a researcher, regulator, educator, and designer 

in the onsite wastewater treatment industry. Dr. Sherman is a former president of the National 

Onsite Wastewater Recycling Association (NOWRA). From 1985-1999, he was a member of 

the staff at the Florida Department of Health and Rehabilitative Services, working in several 

capacities in the epidemiology and environmental health sections. He also served as a former 

president of the Florida Onsite Wastewater Association. Dr. Sherman received his B.S. degree in 

biology from the State University of New York at Stony Brook, another B.S. degree (civil 

engineering) from Florida State University, his M.S. degree in biology from the University of 

South Carolina, and his Ph.D. degree in oceanography from Florida State University. 

Kurt Stephenson is an associate professor of environmental and natural resource economics in 

the Department of Agricultural and Applied Economics at the Virginia Polytechnic Institute and 

State University. His professional objective is to better integrate economic perspectives and 

analysis into decision-making related to water resource issues. Dr. Stephenson is particularly 

interested in application of economic analysis to interdisciplinary research of policy issues. The 

design and implementation of market-based policies to secure environmental objectives is a 

primary area of study within this context. He is currently involved in determining effective 
Appendix B 115 

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strategies for reducing nutrient loads in the Opequon Watershed in Virginia and West Virginia, 

including evaluating the cost effectiveness and feasibility of using urban nonpoint source 

controls (including stormwater management) as an offset to growth in point source loads. Dr. 

Stephenson received his B.S. degree in economics from Radford University, his M.S. degree in 

agricultural economics from Virginia Tech, and his Ph.D. degree in economics from the 

University of Nebraska. 

Michael B. Tate is the Chief of Technical Services at the Kansas Department of Health and 

Environment. Mr. Tate is a licensed professional engineer with 20+ years experience in the 

environmental field. His technical expertise is in water quality and wastewater permitting, with 

additional experience in drinking water, solid waste, and hazardous waste. He manages a section 

responsible for establishing and enforcing water quality standards, and wastewater permitting in 

Kansas. Mr. Tate received his B.S. degree in civil engineering and his M.S. in bioenvironmental 

engineering, both from Oklahoma State University. 

Alan H. Vicory serves as executive director and Chief Engineer for the Ohio River Valley Water 

Sanitation Commission (ORSANCO). His previous responsibilities were with the Commission 

staff as environmental engineer and manager of technical services which included establishment 

of regulatory requirements for discharges, water quality and biological monitoring systems, 

detection and response to spills, applied research, coordination of states and federal programs 

and public education and involvement. He is a Registered Professional Engineer and Board 

Certified in environmental engineering (water and wastewater) by the American Academy of 

Environmental Engineers. He is Past Chairman of the Board of the Water Environment 

Research Foundation (WERF) and former Chairman of the International Water Association’s 

(IWA) Watershed and River Basin Management Specialist Group. He also is a Past President of 

the American Academy of Environmental Engineers (AAEE) and the Association of State and 

Interstate Water Pollution Control Administrators (ASIWPCA). Mr. Vicory received a B.S. 

degree in Civil Engineering from Virginia Military Institute. 

LaJuana S. Wilcher is a Partner with the law firm English, Lucas, Priest & Owsley, L.L.P. in 

Bowling Green, Kentucky. Her previous positions included work with two international law 

firms in Washington, D.C.—Winston & Strawn (1993-1996) and LeBoeuf, Lamb, Greene & 

Mac Rae, L.L.P. (1996-2002). Ms. Wilcher served as the Assistant Administrator of Water for 

the United States Environmental Protection Agency from 1989 to 1993. While at the Office of 

Water (1989-1993), the agency promulgated new regulations addressing storm water, drinking 

water, biosolids (sewage sludge) and water quality standards for toxics, among other things. Ms. 

Wilcher helped lead EPA’s watershed protection approach and Clean Water Act section 319 

nonpoint source grant program. She also led EPA’s involvement in the Exxon Valdez oil spill 

litigation negotiations. She received her B.S. degree in biology from Western Kentucky 

University, and her J.D. degree from Salmon P. Chase College of Law, Northern Kentucky 

University. 
116 Review of the EPA’s Economic Analysis of Final Water Quality Standards in Florida 

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STAFF

Laura J. Ehlers is a senior staff officer for the Water Science and Technology Board of the 

National Research Council. Since joining the NRC in 1997, she has served as the study director 

for 16 committees, including the Committee to Review the New York City Watershed 

Management Strategy, the Committee on Bioavailability of Contaminants in Soils and Sediment, 

the Committee on Assessment of Water Resources Research, and the Committee on Reducing 

Stormwater Discharge Contributions to Water Pollution. Ehlers has periodically consulted for 

EPA’s Office of Research Development regarding their water quality research programs. She 

received her B.S. from the California Institute of Technology, majoring in biology and 

engineering and applied science. She earned both an M.S.E. and a Ph.D. in environmental 

engineering at the Johns Hopkins University.