FINAL NMC Approved Mar. 4, 2010 

Tampa Bay Nitrogen Management Consortium Comments and 

Request Regarding the Development of Protective Loads for the 

Tampa Bay Estuary as It Relates to Establishing Numeric 

Nutrient Criteria for Lakes, Flowing Waters and Estuaries in 

Florida 

March 4, 2010 

Comments provided by the Tampa Bay Nitrogen Management Consortium. 

Participants include: 

Tampa Bay Estuary Program 

U.S. Environmental Protection Agency 

MacDill Air Force Base 

Florida Department of Environmental Protection 

Fl. Dept. of Agriculture & Consumer Services 

Florida Department of Transportation 

Southwest Florida Water Management District 

Tampa Bay Regional Planning Council 

Tampa Port Authority 

Hillsborough County 

Manatee County 

Pasco County 

Pinellas County 

Polk County 

City of Bradenton 

City of Clearwater 

City of Gulfport 

City of Lakeland 

City of Largo 

City of Mulberry 

City of Oldsmar 

City of Palmetto 

City of Plant City 

City of Safety Harbor 

City of St. Petersburg 

City of Tampa 

Mosaic Company 

Kinder Morgan Bulk Terminals, Inc. 

Tampa Electric Company 

CF Industries 

CSX Transportation 

Eastern Associated Terminals Co., LLC 

Tropicana Products, Inc. 

Kerry I&F Contracting 

Tampa Bay Water 

Trademark Nitrogen 

Yara North America 

Alafia Preserve, LLC 

Eagle Ridge, LLC 

LDC Donaldson Knoll Investments, LLC
FINAL NMC Approved Mar. 4, 2010 

i 

CONTENTS 

CONTENTS.......................................................................................................................................i

Summary ......................................................................................................................................... 1

1. Introduction ............................................................................................................................... 1

2. Tampa Bay’s Road to Recovery ............................................................................................... 2

3. Development of the Tampa Bay Nutrient Management Strategy ............................................. 5

4. Concerns with EPA’s Draft Rule ............................................................................................... 8

5. Recommended Protective Nutrient Loads for the Tampa Bay Estuary.................................... 9

LIST OF ATTACHMENTS............................................................................................................. 16
FINAL NMC Approved Mar. 4, 2010 

1 

Summary 

The Tampa Bay Nitrogen Management Consortium (NMC) asserts that the 

nutrient loads approved by EPA and FDEP as regulatory goals for Tampa 

Bay are more appropriate than EPA’s draft protective loads for the Tampa 

Bay estuary and provide for the full aquatic life protection and support for 

all designated uses in the estuary. Furthermore, the Tampa Bay NMC 

requests that EPA finalize the Tampa Bay estuary’s protective loads when 

establishing downstream protective values for flowing waters in the Tampa 

Bay watershed as part of the second phase of this rulemaking process in 

coordination with the proposal and finalization of numeric criteria for 

estuarine and coastal waters that is anticipated to occur in 2011.

1. Introduction 

This paper provides comments from the Tampa Bay Nitrogen Management Consortium 

(NMC) on the protective loads proposed for the Tampa Bay estuary in EPA’s draft 

numeric nutrient criteria for lakes and flowing waters in the State of Florida (Docket ID 

No. EPA-HQ-OW-2009-0596). And, as was requested by EPA in the draft rule, this 

document and supporting attachments serve to provide EPA with an alternative, 

resource-based approach to address protection of downstream water quality that 

attains and maintains the State’s designated uses in the Tampa Bay estuary. 

The Tampa Bay NMC approach that has established state and federally-approved 

nutrient loading targets for the estuary follows EPA’s technical guidance that quantitative 

stressor-response relationships are the most preferred methodology in establishing 

numeric nutrient criteria. Multiple lines of empirical evidence justify maintaining existing 

total nitrogen (TN) and total phosphorus (TP) loads to the Tampa Bay estuary. Water 

quality and clarity in the Bay has improved tremendously since significant management 

actions were initiated starting in the 1980s, seagrass acreage has increased to the 

highest levels observed since the 1950s and continues to increase, and economicallyimportant fish and wildlife populations have been maintained since routine monitoring 

programs began in the 1990s. 

The Tampa Bay NMC thanks EPA for recognizing that, for particular estuaries, sitespecific analyses should be used instead of EPA’s general approach for establishing 

protective estuarine loads and downstream protective values in the final lakes, flowing 

waters, and estuaries rules. We believe the documentation provided in this public 

comment clearly shows that the analyses conducted by the Tampa Bay NMC provide a 

defensible and protective alternative for inclusion in the final numeric nutrient criteria for 

lakes, flowing waters and estuaries in the State of Florida. 

Based on these findings, the Tampa Bay NMC requests that EPA acknowledge that 

existing TN and TP loads to the Tampa Bay estuary are appropriate and defensible 

protective loads. The Tampa Bay NMC recommends that EPA finalize the Tampa Bay 

estuary’s protective loads when establishing downstream protective values for flowing 

waters in the Tampa Bay watershed as part of the second phase of this rulemaking 

process in coordination with the proposal and finalization of numeric criteria for estuarine 

and coastal waters that is anticipated to occur in 2011. 
FINAL NMC Approved Mar. 4, 2010 

2 

The Tampa Bay NMC is providing this technical feedback to EPA to: 

1. describe the improvements in the Tampa Bay ecosystem in response to the 

development and implementation of an adaptive nutrient management strategy 

for the Tampa Bay estuary; 

2. describe the adaptive nutrient management strategy developed by the 

stakeholder-driven process spearheaded by the Tampa Bay NMC and facilitated 

by the Tampa Bay Estuary Program (TBEP); 

3. demonstrate that appropriate protective loads for the Tampa Bay estuary should 

be established to maintain TN and TP loads at existing levels consistent with 

Tampa Bay’s adaptive nutrient management strategy; and, 

4. provide EPA with the Tampa Bay NMC’s recommended protective loads for the 

Tampa Bay estuary that should be promulgated into the final numeric nutrient 

criteria for lakes, flowing waters and estuaries in the State of Florida. 

2. Tampa Bay’s Road to Recovery 

Water quality in Tampa Bay declined from the 1950s-1970s as population growth led to 

increased discharges of partially treated sewage with large amounts of nutrients directly 

to Tampa Bay. Algae blooms and fish kills were common throughout the latter part of 

this period and almost 50% of the seagrass in the bay died off as a result of insufficient 

light and poor water quality. Unregulated dredge and fill operations further contributed to 

the problem by clouding the water and physically removing portions of bay bottom from 

being re-colonized by seagrass. 

A significant turning point for Tampa Bay occurred in the 1980s when implementation of 

state legislation known as the Grizzle-Figg Act (Florida Statute 403.086), which was first 

adopted in the early 1970s, came into effect requiring more stringent treatment 

standards for wastewater plants discharging to Tampa Bay and its watershed. Upgrades 

to the City of Tampa’s Howard F. Curren Plant at Hookers Point during the late 1970s to 

advanced wastewater treatment increased nutrient removal and significantly reduced the 

amount of nitrogen being discharged into the bay. Also across the bay, the City of St. 

Petersburg pioneered the country’s first large-scale reclaimed wastewater program, 

reusing treated wastewater for irrigation of lawns and golf courses rather than 

discharging it into the bay. The advanced treatment and reuse standards set forth in 

Grizzle-Figg legislation provided the bay with a kick start for its turnaround. 

The quality of bay waters initially responded quickly to the reductions in nutrient loadings 

from point sources discharging to the bay in the early 1980s (Figure 1). Water quality in 

the bay has been further enhanced with the 1985 enactment of state legislation requiring 

more stringent stormwater treatment regulations (Florida Administrative Code: 40D-4; 

40E-40), additional upgrades of sewage treatment plants in the watershed to advanced 

wastewater standards and/or to reuse disposal, and voluntary nutrient reduction projects 

implemented through the Tampa Bay NMC. The Tampa Bay NMC is an ad-hoc publicprivate partnership that includes federal and state regulators, local governments, and 

key-industry stakeholders focused on managing nutrient inputs to the Tampa Bay 

estuary. Currently, the NMC has proactively developed nutrient loading limits for all 

major nutrient sources discharging to Tampa Bay. Collectively, both the voluntary 

actions of the Tampa Bay NMC and state regulatory actions adopted in the Tampa 

Bay watershed have served as the adaptive nutrient management strategy in the 

bay over the past quarter century.
FINAL NMC Approved Mar. 4, 2010 

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As a result of this adaptive nutrient management approach in Tampa Bay, existing total 

nitrogen and phosphorus loadings are currently half the levels of what was 

discharged to the bay in the 1970s (Figure 2) despite an increase in population to 

about 2.5 million residents in the Tampa Bay region (Figure 3). Maintenance of 

existing nutrient loads to Tampa Bay has currently resulted in the bay meeting its 

designated uses and supporting full aquatic life protection. This includes the restoration 

and preservation of important seagrass resources, as well as maintaining and balancing 

the phytoplankton-based food web critical to the production of fish and wildlife 

populations in Tampa Bay. 

For instance, concentrations of chlorophyll-a – a key indicator of eutrophication and a 

parameter used in assessing progress in managing nutrient inputs to Tampa Bay – 

dropped dramatically in all major segments of the bay during the early 1980s. In 

Hillsborough Bay alone, the average chlorophyll-a concentrations decreased from 

37 μg/L in 1982 to less than 15 μg/L (Figures 1.A. & 3). Since 1992, the major bay 

segments of Tampa Bay have met chlorophyll-a targets appropriate to support the 

expansion of seagrass nearly 80% of the time (Figure 4). For those years when 

targets were not met, anomalous rainfall events (El Niño years) likely contributed to 

exceedences. 

Historically, events such as unseasonable heavy rains or unanticipated spills have 

occasionally resulted in the Bay not meeting water quality thresholds indicative of the 

maintenance of existing nutrient inputs for a short period of time. Most recently in 2009, 

anomalous May rainfall served as a catalyst for a nuisance algae bloom (Pyrodinium 

bahamense) in upper Tampa Bay. The bloom resulted in water discoloration and 

reduced clarity during June and July 2009 and excessive chlorophyll-a concentrations 

during these months in the Old Tampa Bay segment; however, fish kills and humanhealth impacts were not reported during this time. 

As part of the adaptive nutrient management strategy employed in Tampa Bay, resource 

managers, scientists and researchers swiftly responded to the 2009 algae bloom event. 

In August 2009, the TBEP convened a special technical session to examine potential 

causes of the bloom, and more importantly, how best to address the causes in order to 

reduce the future possibility of nuisance algae blooms in Old Tampa Bay. Academic and 

agency scientists specializing in algae blooms in Florida hypothesized that the pulsed 

flow and associated nutrient flush from the heavy, unseasonal May rainfall resulted in 

conditions conducive to bloom formation, but that additional information was needed to 

determine the root causes of its initiation and persistence during the summer of 2009. 

Additionally, several significant actions by local governments and the TBEP have 

occurred since the 2009 algae bloom to support the adaptive nutrient management 

strategy for Tampa Bay. In January 2010, Pinellas County (a highly urbanized county 

located in the watershed of Old Tampa Bay) approved a residential fertilizer 

management ordinance. This ordinance includes a ban on nitrogen residential fertilizer 

application during the rainy summer months (June 1- September 30) and also includes a 

ban on the retail sales of these products during the rainy season. The application ban 

will be in effect for 2010, followed by enforcement of the retail ban in 2011. In addition, at 

their February 2010 meeting, the elected officials of the TBEP Policy Board approved 

funding for additional studies as recommended by TBEP technical advisors to determine 

the causes of bloom formation. The studies will be used to identify appropriate, specific 
FINAL NMC Approved Mar. 4, 2010 

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and effective management actions to reduce the potential for future bloom formations in 

this portion of Tampa Bay. 

Since 1982, with improved water clarity resulting from nutrient management 

actions, nearly 8,000 acres of seagrass have been naturally recovered in Tampa 

Bay. Recent estimates also indicate that the rate of seagrass expansion has increased 

over the past decade (Figure 5). From 1999-2008 seagrass have expanded at a rate of 

about 509 acres per year compared to approximately 428 acres per year for the 1988-

1998 period. 

Maintaining adequate conditions for seagrass growth and expansion has not been the 

only goal for the adaptive nutrient management strategy developed for Tampa Bay. As 

for other estuaries, Tampa Bay supports a phytoplankton-based food web critical for 

supporting the designated uses of maintaining and enhancing fish and wildlife 

production. Nutrient load reductions, as well as other restoration efforts have promoted 

the long-term maintenance of a balanced ichthyofaunal assemblage in Tampa Bay1

. As 

for species that are directly dependent on phytoplankton production in the bay, young-ofthe-year abundance of striped mullet, Mugil cephalus, has remained relatively constant 

over the recent period (Figure 6). Striped mullet are an algae-eating species that are 

economically important in Florida and serve as key trophic intermediates of balanced 

phytoplankton-based food webs in southeastern US estuaries2

. Notably, peak indices of 

abundance for this species have occurred when chlorophyll-a concentrations in the bay 

have exceeded targets due to anomalous events. 

Likewise, other trophic levels dependent upon a balanced phytoplankton-based food 

web show peaks in abundance during anomalous nutrient loading events. Baitfishfeeding bird species nesting in Tampa Bay, including the brown pelican (Pelecanus 

occidentalis) follow the patterns observed for striped mullet (Figure 7). Increases in 

nesting pairs were observed in the El Niño years when high nutrient loads and 

chlorophyll-a levels were observed in Tampa Bay. 

Based on these lines of empirical evidence, the Tampa Bay NMC asserts that the 

existing adaptive nitrogen management strategy developed for Tampa Bay has been 

shown to support full aquatic life protection and designated uses in Tampa Bay. The 

premise of this strategy is to maintain existing TN and TP loads at levels that will 

support a balanced ecosystem. This balance has resulted in the recovery of seagrass 

resources by maintaining appropriate water clarity in the Bay while supporting and 

maintaining the Bay’s fish and wildlife populations through an adequate phytoplanktonbased food web. The evolution and justification of this strategy for Tampa Bay is 

described in the next section. 

 

1

 Matheson, R.E., R.H. McMichael, T.C. MacDonald & G.E. McLaughlin. In Press. A Brief History of the Fish Fauna of 

Tampa Bay. Proceedings of the 5th Tampa Bay Area Scientific Information Symposium, St. Petersburg, FL. 

October 20-23, 2009. 18 pp. 2

 Wenner, C.A., W.A. Roumillat, J.E. Moran M.B. Maddox, L.B. Daniel and J.W. Smith. 1990. Investigations on the life 

history and population dynamics of marine recreational fishes in South Carolina, part 1. South Carolina Marine 

Resources Research Institute, Completion reports, Project F-37, Charleston and Project F-31, Brunswick. 
FINAL NMC Approved Mar. 4, 2010 

5 

3. Development of the Tampa Bay Nutrient 

Management Strategy 

The Tampa Bay Estuary Program (TBEP) was established in 1991 to help local 

governments, agencies, and other stakeholders in the Tampa Bay area develop a plan 

to sustain the recovery of Tampa Bay. The TBEP partners adopted a Comprehensive 

Conservation and Management Plan in December 1996 (subsequently updated in 2006; 

Attachment A) that included measurable goals for the achievement of the Bay’s 

designated uses and to support full aquatic life protection. Among these goals was the 

restoration of bay water quality to support the recovery of seagrass resources while 

maintaining and enhancing the Bay’s fisheries production and other designated uses 

through bottom-up processes. 

Significant resources, commitments, and investments have been made by TBEP 

partners to achieve these goals with measured success. Public and private parties that 

comprise the TBEP management and policy boards unanimously adopted a strategy that 

limits nutrient loading to the major bay segments of Tampa Bay. These limits ensure that 

adequate water clarity and light levels are maintained in the bay on an annual basis to 

promote seagrass recovery. These limits also provide a balance between the recovery of 

seagrass resources and maintaining and enhancing the phytoplankton-based food web 

and fisheries production long recognized in Tampa Bay. To further reinforce their 

commitment in maintaining these ecosystem-based restoration goals for Tampa Bay, 

local government and agency partners formally adopted an Interlocal Agreement in 1998 

(Attachment B). 

Simultaneously in August 1996, the Tampa Bay Estuary Program’s governmental 

partners joined with key industries in the Tampa Bay region to create an ad-hoc 

public/private partnership known as the Tampa Bay Nitrogen Management Consortium. 

The Consortium’s intent and mission was to implement an Action Plan to meet the 

protective nutrient load targets developed for Tampa Bay. During development of the 

targets, bioassay experiments, empirically-derived nutrient-response relationships, and 

water quality modeling simulations indicated that controlling nitrogen loads to the bay 

should be the primary watershed management focus to limit phytoplankton production 

and allow for improvements in bay water clarity (Attachment C). These early studies 

clearly established that nitrogen loads were the limiting nutrient in the Tampa Bay 

estuary and that phosphorus loadings to the bay from the enriched Bone Valley 

region were not controlling estuarine production.

The original Consortium Action Plan, entitled Partnership for Progress (Attachment D), 

consisted of more than 100 projects that collectively reduced or precluded nitrogen 

discharges to the bay by an estimated 134 tons each year between 1995 and 1999. 

Since 1999, an additional 138 projects have been implemented to reduce nitrogen loads 

to the bay by about 298 tons each year. In total, from 1992-present, Consortium 

participants have invested over $430 million in projects and actions to reduce 

nutrient loads to Tampa Bay in order to adaptively manage for and meet the 

protective load targets for the bay (Attachment E).

The commitments and projects implemented by Consortium participants have served as 

the core of a larger nutrient management strategy for Tampa Bay that includes: 
FINAL NMC Approved Mar. 4, 2010 

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1) achieving a resource-based management goal of restoring/preserving baywide 

seagrass resources and habitats while maintaining and enhancing fisheries 

production in the bay (Attachment F); 

2) achieving chlorophyll-a and nutrient reduction targets specific for each major 

bay segment that support the recovery of seagrass resources (Attachment G); 

3) identifying a general apportionment of responsibility for meeting the nutrient 

reduction targets within the major bay segments (Attachment D & H); and 

4) tracking whether adequate water quality is being maintained and, as a result, 

seagrass resources are being restored (Attachment I) and full aquatic life support 

is protected (Attachment J). 

In November 2002, the Florida Department of Environmental Protection (FDEP) 

concluded that the Tampa Bay Nitrogen Management Consortium’s nitrogen 

management strategy provided reasonable assurance that the state water quality criteria 

for nutrients would be met in Tampa Bay (Attachment K). Prior to this state 

determination, the U.S. Environmental Protection Agency (EPA) recognized a 1998 

action by FDEP that proposed a total maximum load (“federally-recognized 

TMDL”) of nitrogen that could be discharged to the bay annually and still meet 

state water quality standards related to nutrients (Attachment L). Both FDEP’s 

reasonable assurance determination and the total maximum nitrogen loading recognized 

by EPA are based on statistical modeling and data analyses peer-reviewed by the 

TBEP, its partners, and state and federal regulators (Attachment M). Thus, the 

Consortium’s nutrient loading targets developed for the major bay segments of Tampa 

Bay (Figure 8) have been acknowledged by both FDEP and EPA as protective nutrient 

loads for this estuary. 

In 2007, additional local governments, industries and agencies located within the Tampa 

Bay watershed were invited to: 1) become participants in the Consortium; 2) continue to 

develop and implement the collaborative watershed approach to nutrient management 

for Tampa Bay; and 3) help further meet the regulatory requirements of FDEP and EPA 

in maintaining protective nutrient loads for Tampa Bay. To date, more than 50 entities 

now actively participate in the Consortium. As a result of this renewed effort and interest 

in maintaining protective nutrient loads for the Tampa Bay estuary, Consortium 

participants submitted a 2007 Reasonable Assurance update to FDEP on January 28, 

2008 (Attachment N) with the expressed intent to develop permit-specific nitrogen load 

allocations for all major dischargers to Tampa Bay by summer 2009. The FDEP 

accepted this updated nitrogen management strategy (Attachment O) with the 

acknowledgment that the Consortium would proactively develop an equitable process 

and define the suggested nitrogen load allocations to all major sources and permitteddischargers within the Tampa Bay watershed that would meet the protective nutrient 

loads defined in the 1998 federally-recognized TMDL (Attachment L). 

Most recently on September 11, 2009, the Consortium approved protective 

nitrogen load allocations for all major sources in the Tampa Bay watershed and 

later finalized the 2009 Reasonable Assurance Addendum: Allocation and 

Assessment Report (on January 22, 2010) for submittal to FDEP (Attachment P) to 

fulfill FDEP’s 2007 reasonable assurance determination (Attachment O) and meet 

the protective estuarine nitrogen loads established in the 1998 federallyrecognized TMDL (Attachment L). This accomplishment will ensure that nutrient loads 

will be managed to support the continued recovery of the Tampa Bay estuary. The 

successful nutrient management strategy that has evolved from the efforts of local 
FINAL NMC Approved Mar. 4, 2010 

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governments, agencies, and industry participants of the Tampa Bay NMC since the 

1990’s, has ensured that the designated uses of the Tampa Bay estuary are and will 

continue to be met in the future. 

To date, this strategy has documented proven results (Attachment Q). The recovery of 

the Tampa Bay ecosystem after decades of decline is unprecedented among urban 

estuaries worldwide and has been cited in numerous peer-reviewed publications3

 as a 

successful nutrient management strategy that has produced desired results. The 

improved water quality and ecological health of the bay is even more remarkable in light 

of strong population growth that has occurred during the recovery period (Figure 3). Bay 

water quality initially responded quickly to reductions in nitrogen loading, and has since 

been maintained at levels that promote the recovery of seagrasses in the bay. From 

1982 to 2008, nearly 8,000 acres of seagrasses have been naturally recovered in the 

bay (Attachment R). The reductions in nitrogen loads to Tampa Bay and resulting 

recovery of seagrasses has also led to overall improvements for other designated uses 

and the support of full aquatic life protection (Attachment H). 

The overall variability in annual dissolved oxygen (DO) concentrations (the difference 

between the observed maximum and minimum values) appears to be declining over 

time, and median DO conditions in all major bay segments are protective of aquatic life 

support (Attachment H). These patterns are consistent with the observed response to 

the reductions in nutrient loadings and algal biomass that have occurred during the past 

quarter century in Tampa Bay. Likewise, fish and wildlife populations in Tampa Bay have 

either shown stable or increasing trends in abundance due to the overall ecosystem 

improvements that have occurred in response to nitrogen load reductions in Tampa Bay 

(Attachment J). The Tampa Bay ecosystem has indeed shown a balanced response to 

the nutrient management strategy employed by TBEP partners; however, it is 

recognized that anomalous events are still occasionally observed in the system and 

continuing adaptive management strategies will need to be employed (Attachment S). 

Regardless of these temporary perturbations, Tampa Bay has seen consistent 

improvement in its water quality and associated designated uses largely through the 

efforts of this stakeholder-driven initiative and state legislation to improve wastewater 

and stormwater treatment. Given the three decades of cooperative and collaborative 

experience that has driven these improvements and understanding of nutrient 

 

3

 Badylak, S. & E.J. Phlips 2008. Spatial and temporal distributions of zooplankton in Tampa Bay, Florida, including observations during a 

HAB event. J. of Plankton Resarch. 30(4):449-465. 

Bricker, S.B. & 6 others. 2008. Effects of nutrient enrichment in the nation’s estuaries: A decade of change. Harmful Algae. 8:21-32. 

Cloern, J.E. & A.D. Jassby. 2009. Patterns and Scales of Phytoplankton Variability in Estuarine–Coastal Ecosystems. Estuaries and 

Coasts. 1559-2731. doi. 10.1007/s12237-009-9195-3. 

Duarte, C.M., D.J. Conley, J. Carstensen & M. Sánchez-Camacho. 2009. Return to Neverland: Shifting baselines affect 

eutrophication restoration targets. Estuaries and Coasts. 32:29-36. 

Johansson, J.O.R. and Lewis III, R.R. 1992. Recent improvements of water quality and biological indicators in Hillsborough Bay, a highly 

impacted subdivision of Tampa Bay, Florida, USA, in Marine Coastal Eutrophication, The Response of Marine Transitional 

Systems to Human Impact: Problems and Perspectives for Restoration, edited by: Vollenweider, R. W., Marchetti, R., and Viviani,

R., Elsevier Press, New York, 1191–1215, 1992. 

Morrison, G., E.T. Sherwood, R. Boler & J. Barron. 2006. Variations in water clarity and chlorophyll a in Tampa Bay, Florida, in 

response to annual rainfall, 1985–2004. Estuaries and Coasts. 29(6):926-931. 

National Research Council. 2000. Clean Coastal Waters – Understanding and Reducing the Effects of Nutrient Pollution, National 

Academy Press, Washington, DC, 2000. 

Nixon, S.W. 2009. Eutrophication and the macroscope. Hydrobiologia. 629:5-19 

Paerl, H.W. 2009. Controlling eutrohpication along the freshwater-marine continuum: Dual nutrient (N and P) reductions are essential. 

Estuaries and Coasts. 32:593-601. 

Rabalais, N.N. & 5 others. 2009. Dynamics and distribution of natural and human-caused coastal hypoxia. Biogeosciences Discussions. 

6:9359–9453. 

Testa, J.M., W.M. Kemp, W.R. Boynton & J.D. Hagy. 2008. Long-Term Changes in Water Quality and Productivity in the Patuxent River 

Estuary: 1985 to 2003. Estuaries and Coasts. 31:1021-1037. 

Waycott, M. & 13 others. 2009. Accelerating loss of seagrass across the globe threatens coastal ecosystems. Proceedings of the 

National Academy of Science. 106(30):12377-12381
FINAL NMC Approved Mar. 4, 2010 

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management for the Tampa Bay estuary, the Tampa Bay Nitrogen Management 

Consortium requests that EPA utilize this adaptive nutrient management strategy for 

defining protective nutrient loads for the Tampa Bay estuary in its proposed rules for 

lakes, flowing waters and estuaries of the State of Florida. As demonstrated above, 

there is considerable evidence that existing loads to the major bay segments of Tampa 

Bay provide for the full aquatic life protection and support for all designated uses in the 

estuary and are therefore within the estuary’s assimilative capacity. 

4. Concerns with EPA’s Draft Rule 

The Tampa Bay NMC has concerns regarding the draft rule for numeric nutrient criteria 

for flowing waters within the Tampa Bay watershed. This rule is based on the initial 

premise that Tampa Bay nutrient loads are above its assimilative capacity. The Tampa 

Bay NMC’s adaptive nutrient management approach in establishing the state and 

federally-approved loading targets for the Tampa Bay estuary followed EPA’s technical 

guidance. The Tampa Bay NMC approach utilizes bay segment specific quantitative 

stressor-response relationships to establish nutrient loading targets for the Tampa 

estuary which, according to EPA guidance, is considered the most preferred method for 

establishing numeric nutrient criteria. Specifically, the Tampa Bay NMC has defined the 

quantitative relationship between nutrient loads and chlorophyll-a levels in each of the 

major bay segments of the Tampa Bay estuary. As demonstrated above, there is 

considerable evidence that existing loads to the major bay segments of Tampa Bay 

provide for the full aquatic life protection and support for all designated uses in the 

estuary. 

The Tampa Bay NMC has other concerns specifically with the application of the USGS 

Spatially Referenced Regression on Watershed Attributes (SPARROW) model for the 

Southeastern US in the Tampa Bay watershed. This model was used to calculate both 

existing and baseline loads for the Tampa Bay watershed and these values were then 

used to estimate the protective loads for the Tampa Bay estuary. While the SPARROW 

model may be appropriate for its expressed purpose (i.e., to examine landscape 

characteristics that influence delivery of nitrogen from sources within the watersheds in 

the Southeastern US), its application to the Tampa Bay watershed is questionable. 

While the peer-reviewed load estimates developed by the Tampa Bay NMC are driven 

by local data sources (e.g., particularly point sources, atmospheric deposition, and 

product handling; Attachment T) the SPARROW coefficients are based on regional 

(southeastern US) data. Thus, the scaling of SPARROW to much smaller basins needs 

to be validated. 

Lastly, the SPARROW estimates do not fully reflect the time-varying loads to an estuary 

and its resulting ecosystem response to nutrient loads derived from the watershed. The 

protective loads for the Tampa Bay estuary, as defined by EPA’s application of the 

SPARROW model, are normalized to hydrologic conditions of a single year (2002), and 

are thus inappropriate for accounting for variations in the Tampa Bay estuary’s 

ecosystem response to nutrient loads and hydrologic residence times. This is particularly 

evident in EPA’s development of a single protective load for the Tampa Bay estuary, 

when the Tampa Bay NMC and other federal and state regulators have recognized the 

need to establish protective nutrient loads for each of the major bay segments of the 

Tampa Bay estuary. These significant concerns, as well as the successful demonstration 

of the approved nutrient management strategy employed in Tampa Bay, were repeatedly 

voiced at EPA’s February 2010 listening sessions in Florida (e.g., Attachment U). 
FINAL NMC Approved Mar. 4, 2010 

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5. Recommended Protective Nutrient Loads for the 

Tampa Bay Estuary 

In order to maintain consistency in the adaptive resource-based nutrient management 

approach utilized in Tampa Bay that ensures: 

1) the protection of the estuary from degradation associated with excessive 

nutrient loadings; 

2) a balance of full aquatic life support being sustained and enhanced; and, 

3) the attainment of all designated uses, 

the Tampa Bay NMC requests that EPA establish the nitrogen and phosphorus loading 

(Table 1), recognized by both FDEP and EPA as being protective of the Tampa Bay 

estuary through separate administrative actions, as the protective nutrient loads for the 

Tampa Bay estuary. As such, the Tampa Bay NMC requests that EPA finalize the 

existing TN and TP loads (specified for each major bay segment in Table 1), as the 

protective loads used in determining downstream protective values for flowing waters 

and as the protective Estuarine Nutrient Criteria for the Tampa Bay estuary. 

Furthermore, the Tampa Bay NMC requests that EPA finalize the protective estuarine 

loads established in Table 1 for nutrients in flowing waters as part of the second phase 

of this rulemaking process in coordination with the proposal and finalization of numeric 

criteria for estuarine and coastal waters that is anticipated to occur in 2011. 

Table 1: Protective nutrient loads for the Tampa Bay estuary established by the 

Tampa Bay Nitrogen Management Consortium, and accepted through 

separate administrative action by FDEP (acceptance of the 2002 RA, 

2007 RA Update & 2009 RA Addendum) and EPA (establishment of the 

1998 federally-recognized TMDL for Tampa Bay). 

Bay Segment 

EPA’s Protective Load to the 

Tampa Bay Estuary Defined in 

the Jan. 14th, 2010 Draft Rule 

for Total Nitrogen Load 

expressed as tons/year 

(kilograms/year) 

Tampa Bay NMC 

Proposed Alternative 

Total Nitrogen Load 

expressed as 

tons/year 

(kilograms/year) 

Tampa Bay NMC 

Proposed Total 

Phosphorus Load 

(Attachment V) 

expressed as 

tons/year 

(kilograms/year) 

Old Tampa Bay None specified 486 (440,892) 104 (94,127) 

Hillsborough Bay None specified 1,451 (1,316,325) 1,093 (993,755) 

Middle Tampa Bay None specified 799 (724,841) 140 (127,673) 

Lower Tampa Bay None specified 349 (316,607) 52 (47,564) 

Remainder of Lower Tampa Bay None specified 629 (570,619) 112 (101,464) 
FINAL NMC Approved Mar. 4, 2010 

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Figure 1: Observed improvements in annual average chlorophyll-a (μg/L; A) and light 

attenuation (m-1; B) for the four main bay segments of Tampa Bay (1974-2008). 

A

B
FINAL NMC Approved Mar. 4, 2010 

11 

1.066 0.812

5.973

0.980

2.370

2.615

0.489

0.024

0.004

0.002

0.002

0.099

0

2

4

6

8

10

1976

(Worst Case Loadings)

2003-2007

(Annual Averages) Time Period

Total Nitrogen Load (1000s tons/year)

Springs

Groundwater

Material Losses

Nonpoint Sources

Point Sources

Atmospheric Deposition

Total: 9,904 tons/yr

Total: 4,533 tons/yr

Figure 2: Contributions of the various sources of nitrogen loads to Tampa Bay in the 1970s 

compared to the most recent estimates available for the 2003-2007 period 

(Source: TBEP 1994; Janicki Environmental, Inc. 2008). 

Figure 3: Comparison of population growth in the three counties bordering Tampa Bay and 

an indicator of bay eutrophication (annual average chlorophyll-a concentrations). 
FINAL NMC Approved Mar. 4, 2010 

12 

Figure 4: Historic attainment of Florida Department of Environmental Protection 

chlorophyll-a thresholds (μg/L) for the main bay segments of Tampa Bay in 

comparison to key adaptive nutrient management strategy milestones. Annual 

average chlorophyll-a threshold concentrations for each of the bay segments 

based on long-term monitoring stations maintained by the Environmental 

Protection Commission of Hillsborough County are: Old Tampa Bay = 9.3 μg/L; 

Hillsborough Bay = 15 μg/L; Middle Tampa Bay = 8.5 μg/L; and Lower Tampa 

Bay = 5.1 μg/L. 

Advanced Wastewater Treatment & 

Reuse Standards Implemented in 

Tampa Bay according to GrizzleFigg Legislation (F.S. 309.086) 

Enhanced Stormwater Regulations 

required through the Southwest 

Florida Water Management 

District’s Permitting Process (F.A.C. 

40D-4, 40E-40) 

Tampa Bay Nitrogen Management 

Consortium formed to manage 

nutrient loads at 1992-1994 levels in 

Tampa Bay through implementation 

of reduction/preclusion projects in 

the watershed. 
FINAL NMC Approved Mar. 4, 2010 

13 

Slope = 428 acres/yr

Slope = 509 acres/yr

20

22

24

26

28

30

32

34

36

38

40

1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Year

Seagrass Acreage (1,000's of acres)

Initial Estimate (Worst Case)

Previous Decade

Recent

Tampa Bay Seagrass Recovery Goal (38, 000 acres)

Figure 5: Seagrass acreage estimates for Tampa Bay from 1982 – 2008. An increase in 

the rate of seagrass expansion was seen for the 1999-2008 period in comparison 

to the previous decade’s estimates (1988-1996) (Source: SWFWMD). 

Figure 6: Variation in young of the year striped mullet, Mugil cephalus, abundance in the 

Tampa Bay estuary. Peak indices of abundance were observed in 1998 and 

2006 (Source: FWRI). 

Indices of Abundance 
FINAL NMC Approved Mar. 4, 2010 

14 

0

500

1000

1500

2000

2500

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Nesting Pairs of Pelican

s

Figure 7: Observed number of brown pelican, Pelecanus occidentalis, nesting pairs in the 

Tampa Bay estuary. Minimal counts observed in 2003 and 2004 were attributed 

to interactions with mammalian predators (Source: Hodgson et al 2006). 
FINAL NMC Approved Mar. 4, 2010 

15 

Figure 8: Watershed boundaries draining to the major bay segments of Tampa Bay. The 

nutrient loading (TN=total nitrogen; TP=total phosphorus) and chlorophyll-a 

concentration targets are listed for each bay segment. For Lower Tampa Bay, the 

remainder nutrient loads are for the combined subwatersheds of the Lower Boca 

Ciega Bay, Terra Ceia Bay, and Manatee River bay segments.
FINAL NMC Approved Mar. 4, 2010 

16 

LIST OF ATTACHMENTS 

ATTACHMENT TITLE DIGITAL FILE NAME

A 

Holland, N., M. Kelley Hoppe & L. Cross. 2006. Charting the Course: The 

Comprehensive Conservation and Management Plan for 

Tampa Bay. Prepared by the Tampa Bay Estuary Program, May 

2006. 151pp. 

ATTACHMENT_A_Final_2006_TBEP_CCMP.pdf 

B 

Tampa Bay Estuary Program. 1998. Tampa Bay National Estuary 

Program: Interlocal Agreement. Prepared by the Tampa Bay 

Estuary Program, February 1998. 54pp. 

ATTACHMENT_B_TBEP_Interlocal_Agreement.pdf 

C 

C.1.: Johansson, J.O.R. 1991. Long-term trends of nitrogen loading, 

water quality and biological indicators in Hillsborough Bay, 

Florida in Treat, S.F. and P. Clark, eds. Proceedings, Tampa Bay 

Area Scientific Information Symposium 2. Feb. 27 – Mar. 1, 1992, 

Tampa, FL. 528pp.

C.2.: Johansson, J.O.R. and R.R. Lewis. 1992. Recent improvements of 

water quality and biological indicators in Hillsborough Bay, a 

highly impacted subdivision of Tampa Bay, Florida, USA pp. 

1199-1215 in R.A. Vollenwedier et al., eds. Marine Coastal 

Eutrophication: The Response of Marine Transitional Systems to 

Human Impact: Problems and Perspectives for Restoration. 

Proceedings of an International Conference, Bologna, Italy, 21-24 

March 1990. 

C.3. Zarbock, H., A. Janicki, D. Wade, D. Heimbuch & H. Wilson. 1994. 

Estimates of Total Nitrogen, Total Phosphorus, and Total 

Suspended Solids Loadings to Tampa Bay, Florida. Prepared 

by Coastal Environmental, Inc. for the Tampa Bay Estuary 

Program. TBEP Technical Publication #04-94. 388pp. 

C.4. Wang, P.F., J. Martin & G. Morrison. 1999. Water quality and 

eutrophication in Tampa Bay, Florida. Estuarine, Coastal and 

Shelf Science. 49:1-20. 

C.5. Dixon, L.K. & 4 others. 2009. Trends and explanatory variables for 

the major phytoplankton groups of two southwestern Florida 

estuaries, U.S.A. Journal of Sea Research. 61:95–102. 

C.6. Johansson. J.O.R. 2009. Nutrient Enrichment Studies of Natural 

Phytoplankton Populations in Tampa Bay: A Summary of 

Results, June 1993-August 2009. City of Tampa, Bay Study 

Group. November 16, 2009.

ATTACHMENT_C1_Johansson_N_Loads_BASIS2.p

df 

ATTACHMENT_C2_Johansson_Lewis_1992.pdf 

ATTACHMENT_C3_TBEP_04_94_TNEstimates.pdf 

ATTACHMENT_C4_Tampa_Bay_WASP_Model_199

9.pdf 

ATTACHMENT_C5_Dixon_Vargo_Johansson_2009.

pdf 

ATTACHMENT_C6_Johansson_Bioassay_1993-

2009.pdf 

D 

Tampa Bay Nitrogen Management Consortium. 1999. Partnership for 

Progress: The Tampa Bay Nitrogen Management Consortium 

Action Plan, 1995-1999. Prepared by the Tampa Bay Estuary 

Program, October 1999. 104pp. 

ATTACHMENT_D_TBEP_Partnership_for_Progress.

pdf 

E Tampa Bay Action Plan Database. 2010. Maintained by the Tampa Bay 

Estuary Program. 

ATTACHMENT_E_TBEP_Action_Plan_02192010.md

b 

F 

Janicki, A.J., D.L. Wade & D.E. Robison. 1995. Habitat Protection and 

Restoration Targets for Tampa Bay. Prepared by Coastal 

Environmental, Inc. for the Tampa Bay Estuary Program. TBEP 

Technical Publication #07-93. 163pp. 

ATTACHMENT_F_TBEP_07_93HabitatRestoreTarge

ts.pdf 

G 

F.1.: Final Action taken by TBNEP Management and Policy Committees, 

June 14, 1996, adopting goals for seagrass acreage, targets for 

segment specific chlorophyll-a concentrations, and a five-year 

nitrogen management strategy to “hold the line” on nitrogen 

loadings for each bay segment. 

F.2.: Final Action taken by TBEP Management and Policy Boards, May 11, 

2001, extending through 2005 the previously adopted chlorophyll 

a concentrations for each bay segment, and the nitrogen 

management strategy to “hold the line”.

ATTACHMENT_G1_RA_F1_FinalAction_June14199

6.pdf 

ATTACHMENT_G2_RA_F2_FinalAction_May112001

.pdf

H 

Janicki Environmental, Inc. 2003. Nitrogen Loadings to Tampa Bay: 

Model Based Estimates of 1998 and 2010 Loads to Major 

Basins, and TN Load Reduction/Preclusion Apportionment.

TBEP Technical Publication #04-03. 27pp. 

ATTACHMENT_H_TBEP_04_03LoadApportionment.

pdf 
FINAL NMC Approved Mar. 4, 2010 

17 

ATTACHMENT TITLE DIGITAL FILE NAME

I 

Janicki, A.J., D.L. Wade & R.J. Pribble. 2000. Developing and 

Establishing a Process to Track the Status of Chlorophyll-a 

Concentrations and Light Attenuation to Support Seagrass 

Restoration Goals in Tampa Bay. TBEP Technical Publication 

#04-00. 70pp. 

ATTACHMENT_I_TBEP_04_00Chlor-A.pdf 

J Poe, A., ed. 2006. Baywide Environmental Monitoring Report, 2002-

2005. TBEP Technical Publication #06-06. 202pp. ATTACHMENT_J_TBEP_06_06_BEMRFinal.pdf 

K 

K.1. D. Joyner (FDEP) letter to H. Greening (TBEP). November 5, 2002. 

Acceptance of the Tampa Bay nitrogen management plan and the 

scientific basis for key plan elements to meet state reasonable 

assurance guidelines. 

K.2. Tampa Bay Estuary Program. 2002. 2002 Reasonable Assurance 

Submittal to the Florida Department of Environmental 

Protection: Tampa Bay Watershed Management Summary. 

Prepared by the Tampa Bay Estuary Program. 

17pp.+attachments. 

ATTACHMENT_K1_RA2002_FDEPLetter.pdf 

ATTACHMENT_K2_2002_RA_Submittal_w_Attachm

ents.pdf

L US Environmental Protection Agency. 1998. Federally-recognized TMDL 

for Tampa Bay. 

ATTACHMENT_L_EPA_TMDL_Tampa_Bay_1998.p

df 

M 

M.1. Janicki, A.J. and D.L. Wade. 1996. Estimating Critical External 

Nitrogen Loads for the Tampa Bay Estuary: An Empirically 

Based Approach for Setting Management Targets. TBEP 

Technical Publication #06-96. 200pp. 

M.2. Morrison, G., and 5 others. 1996. Estimated nitrogen fluxes and 

nitrogen-chlorophyll relationships in Tampa Bay, 1985-1994 

pp. 249- 268 in Treat, S.F., ed. Proceedings of the 3rd Tampa Bay 

Area Scientific Information Symposium, October 21-23, 1996, 

Clearwater, FL.

M.3. Janicki Environmental, Inc. 2001. Tampa Bay Estuary Program 

Model Evaluation and Update: Chlorophyll a – Light 

Attenuation Relationship. TBEP Technical Publication #06-01. 

35pp. 

M.4. Janicki Environmental, Inc. 2001. Tampa Bay Estuary Program 

Model Evaluation and Update: Nitrogen Load – Chlorophyll a 

Relationship. TBEP Technical Publication #07-01. 21pp. 

ATTACHMENT_M1_TBEP_06_96ExternalTNLoads.p

df 

ATTACHMENT_M2_Morrison_BASIS3_Nitrogen_Flu

x.pdf 

ATTACHMENT_M3_TBEP_06_01-CHL-LIGHT.pdf 

ATTACHMENT_M4_TBEP_07_01-TN-CHL.pdf

N 

Tampa Bay Nitrogen Management Consortium. 2008. 2007 Reasonable 

Assurance Update Submittal to the Florida Department of 

Environmental Protection: Tampa Bay Watershed 

Management Summary. Prepared by the Tampa Bay Estuary 

Program. 45pp.+attachments. 

ATTACHMENT_N_2007_RA_Update_Submittal_w_A

ttachments.pdf 

O 

D. Joyner (FDEP) letter to H. Greening (TBEP). May 28, 2008. Acceptance 

that adequate progress has been maintained in achieving the 

Tampa Bay nitrogen management plan and the scientific basis for 

key plan elements to meet state reasonable assurance guidelines. 

ATTACHMENT_O_FDEP_RA_Approval_Letter_5280

82.pdf 

P 

Tampa Bay Nitrogen Management Consortium. 2009. 2009 Reasonable 

Assurance Addendum: Allocation and Assessment Report. 

Prepared by the Tampa Bay Estuary Program. 89pp.+appendices. 

ATTACHMENT_P_2009_RA_Addednum_Submittal_

w_Appendices.pdf 

Q 

Greening, H. and A. Janicki. 2006. Toward reversal of eutrophic 

conditions in a subtropical estuary: Water quality and 

seagrass response to nitrogen loading reductions in Tampa 

Bay, Florida, USA. Environmental Management. 38(2):163-178. 

ATTACHMENT_Q_Greening&JanickiEnv_Man_2006-

Toward_Reversal_of_Eutrophic_Conditions.pdf 

R 

Greening, H., L. Cross, and E. Sherwood. 2010. A multi-scale approach to 

seagrass recovery in Tampa Bay, Florida, USA. In K.A. 

McGraw and R. M. Thom, (eds). Restoration and Protection: Are 

We Having An Effect? Ecological Restoration, forthcoming. 

ATTACHMENT_R_Greening,Cross,SherwoodEnv_Res_2010-

Tampa_Bay_Seagrass_Recovery.pdf 

S 

Greening, H. 2010. Memo to E. King, D. Keehner, J. Keating and J. 

Giatinna (US EPA) regarding the 2010 Algae bloom in Tampa 

Bay. February 23, 2010, Washington, D.C. 

ATTACHMENT_S_Greening_2010_Memorandum_R

egarding_TB_Bloom.pdf 
FINAL NMC Approved Mar. 4, 2010 

18 

ATTACHMENT TITLE DIGITAL FILE NAME

T 

T.1. Zarbock, H., A. Janicki and S. Janicki. 1996. Estimates of Total 

Nitrogen, Total Phosphorus, and Total Suspended Solids 

Loadings to Tampa, Bay, Florida. Technical Appendix: 1992-

94 Total Nitrogen Loads to Tampa Bay. TBEP Technical 

Publication #19-96. 50pp. 

T.2. Pribble, J.R., A. Janicki, K. Hackett, and S. Janicki. 2001. Estimates of 

Total Nitrogen, Total Phosphorus, and Total Suspended 

Solids Loadings to Tampa, Bay, Florida. Technical Appendix: 

1995-1998 Total Nitrogen Loads to Tampa Bay. TBEP 

Technical Publication #05-01. 227pp. 

T.3. Poe, A., Hackett, K., Janicki, S., Pribble, R., and A. Janicki. 2005. 

Estimates of Total Nitrogen, Total Phosphorus, Total 

Suspended Solids, and Biochemical Oxygen Demand 

Loadings to Tampa Bay, Florida: 1999-2003. TBEP Technical 

Publication #02-05. 374pp. 

T.4. Janicki Environmental, Inc. 2008. Estimates of Total Nitrogen, Total 

Phosphorus, Total Suspended Solids, and Biochemical 

Oxygen Demand Loadings to Tampa Bay, Florida: 2004-2007. 

Prepared for: Florida Department of Environmental Protection. 

86pp.

ATTACHMENT_T1_TBEP_19_96_Load_Estimates_

TBay.pdf 

ATTACHMENT_T2_TBEP_05_01-95-98_LOADS.pdf 

ATTACHMENT_T3_TBEP_02_05_Loadings99_03.pd

f 

ATTACHMENT_T4_TB_Loads_2004-2007_Final.pdf 

U 

U.1. Greening, H. 2010. Presentation to US EPA Public Listening 

Sessions entitled “Downstream Protective Loads to Tampa 

Bay: Public comment from the Tampa Bay Nitrogen 

Management Consortium.” February 17, 2010, Orlando, FL.

U.2. Janicki, T. 2010. Presentation to US EPA Public Listening Sessions 

entitled “Downstream Protective Loads to Tampa Bay: Public 

comment from the Tampa Bay Nitrogen Management 

Consortium.” February 16, 2010, Tallahassee, FL. 

ATTACHMENT_U1_GreeningPublic_Comments_to_EPA_Orlando_Feb172010.

pdf 

ATTACHMENT_U2_JanickiPublic_Comments_to_EPA_Tallahassee_Feb162

010.pdf 

V 

Janicki Environmental, Inc. 2010. Development of Proposed Tampa Bay 

Protective Total Phosphorus Loads. TBEP Technical 

Publication #04-10. 4pp. 

ATTACHMENT_V_

TBEP_04_10_Final_Development_of_Protective_

TP_Loads.pdf