# DRAFT

Chesapeake Bay Total Maximum Daily Load

September 24, 2010

U.S. Environmental Protection Agency

Region 3
Water Protection Division Office of Regional Counsel Philadelphia, Pennsylvania

U.S. Environmental Protection Agency

Region 3 Chesapeake Bay Program Office Annapolis, Maryland

and

U.S. Environmental Protection Agency

Region 2 Division of Environmental Planning and Protection

New York, New York

in coordination with

U.S. Environmental Protection Agency

Office of Water Washington, D.C.

and in collaboration with

Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia and the District of ColumbiaDRAFT Chesapeake Bay TMDL

ii September 24

, 2010 

### Draft Chesapeake Bay TMDL Executive Summary

Introduction The U.S. Environmental Protection Agency has released the draft Chesapeake Bay Total Maximum Daily Load (TMDL), a ―pollution diet‖ that will compel sweeping actions to restore the Chesapeake Bay and its vast network of streams, creeks and rivers.

The TMDL was prompted by insufficient restoration progress over the last several decades in the Bay. The TMDL is required under federal law and responds to consent decrees in Virginia and D.C. dating ba ck to the late 1990s. It is also a keystone commitment of a federal strategy to meet President Obama‘s Executive Order to restore and protect the Bay.

The draft TMDL

– the largest ever developed by EPA

– includes pollution limits to meet water quality sta ndards in the Bay and its tidal rivers. The TMDL is designed to ensure that all pollution control measures to fully restore the Bay and its tidal rivers are in place by 2025, with 60 percent of the actions completed by 2017. The final TMDL will be establis hed December 31.

On July 1, EPA set draft Bay watershed limits for nitrogen and phosphorus at 187.4 million and 12.5 million pounds per year, respectively, and on Aug. 13 set a range of allowable sediment pollution levels at between 6.1 and 6.7 billion pounds per year. These pollution limits were further divided by jurisdiction and major river basin based on state

- of

- the

- art modeling tools, extensive monitoring data, peer

- reviewed science, and close interaction with state partners.

The TMDL is supported by accountability measures to ensure cleanup commitments are met, including short

- and long

- term benchmarks, a tracking and accounting system, and additional federal backstop measures, if necessary, to spur progress.

EPA incorporated federal backstop me asures into the draft TMDL because of deficiencies in the majority of draft pollution reduction plans submitted by the states and District of Columbia in early September. Most of these draft Watershed Implementation Plans (WIPs) did not identify
programs t o sufficiently reduce pollution to meet TMDL allocations and provide assurance the programs could be implemented. As a result, EPA‘s backstop measures focus on tightening controls on federally permitted point sources of pollution, such as wastewater treatm ent plants, large animal agriculture operations and municipal stormwater systems.

EPA proposed more extensive backstop allocations for Pennsylvania, Virginia, New York, Delaware and West Virginia. Only minor changes were made to the plans for Maryland an d the District of Columbia. The jurisdictions will have the opportunity to revise and strengthen their plans before final versions are due on November 29. During this time, EPA will engage jurisdictions to share best approaches from the WIPs across the jurisdictions and provide EPA

g uidan ce on the most effective pollution controls. When those final WIPs are submitted, EPA will again evaluate the plans to determine if EPA backstop allocations can be replaced with sufficiently improved sta te commitments

.

The release of the draft TMDL begins a 45

- day public comment period that will include 18 public meetings in all six watershed states and the District of Columbia. The public meetingDRAFT Chesapeake Bay TMDL

iii September 24

, 2010

schedule, including registration links for webinars, is at http://www.epa.gov/chesapeakebaytmdl

. The website provides instructions for accessing the draft TMDL and providing comments.

T MDL Background The Clean Water Act sets as a goal that all waters in the U nited States be ―fishable‖ and ―swimmable,‖ and requires states and the District of Columbia to establish water quality standards to measure the health of water bodies relative to these primary environmental goals. The Clean Water Act also requires jurisdi ctions to develop a list of waterways that are impaired by pollutants and do not meet water quality standards. A Total Maximum Daily Load (TMDL) must be developed for certain waterways on the impaired list. A TMDL is essentially a ―pollution diet‖ that ide ntifies the maximum amount of a pollutant the waterway can receive and still meet water quality standards.

Most of the Chesapeake Bay and its tidal waters are listed as impaired because of excess nitrogen, phosphorus and sediment. These pollutants cause a lgae blooms that consume oxygen and create ―dead zones‖ where fish and shellfish cannot survive, block sunlight that is needed for underwater grasses, and smother aquatic life on the bottom. The high levels of nitrogen, phosphorus and sediment enter the wa ter from agricultural operations, urban and suburban runoff, wastewater facilities, air pollution and other sources, including septic systems. Despite some reductions in pollution during the past 27 years of restoration due to extensive efforts by federal, state and local governments; non

- governmental organizations; and stakeholders in the agriculture, urban/suburban and wastewater sectors, there has been insufficient progress toward meeting the water quality goals for the Chesapeake Bay and its tidal water s.

Since 2000, the seven jurisdictions in the Chesapeake Bay watershed (Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia) and the U.S. Environmental Protection Agency, who along with the Chesapeake Bay Commissi on are partners in the Chesapeake Bay Program, have been planning for a Chesapeake Bay TMDL.

Since September 2005, the seven jurisdictions have been actively involved in decision

- making to develop the TMDL. In the October 2007 meeting of the Chesapeake B ay Program‘s Principals‘ Staff Committee, the jurisdictions and EPA agreed that EPA would establish the TMDL. Since 2008, EPA has sent official letters to the jurisdictions detailing all facets of the TMDL, including: schedules for developing the TMDL and pollution reduction plans, EPA‘s expectations and evaluation criteria for jurisdiction plans to meet the TMDL pollution limits, reasonable assurance for controlling nonpoint source pollution, and backstop actions that EPA could take to ensure progress.

Th e TMDL also resolves commitments made in a number of consent decrees , Memos of Understanding, and settlement agreements dating back to the late 1990s that address certain

waters identified as impaired in the District of Columbia, Delaware, Maryland and Vir ginia

.

Additionally, President Obama issued Executive Order 13508 on May 12, 2009, which directed the federal government to lead a renewed effort to restore and protect the Chesapeake Bay and its watershed. The Chesapeake Bay TMDL is a keystone commitmen t in the strategy developed by federal agencies to meet the President‘s Executive Order.DRAFT Chesapeake Bay TMDL

iv September 24

, 2010

More than 40,000 TMDLs have been completed across the United States, but the Chesapeake Bay TMDL will be the largest and most complex thus far

– it is designed to achieve significant reductions in nitrogen, phosphorus and sediment pollution throughout a 64,000

- square

- mile watershed that includes the District of Columbia and large sections of six states. The TMDL is actually a combination of 92 smaller TM DLs for individual Chesapeake Bay tidal segments and includes pollution limits that are sufficient to meet state water quality standards for dissolved oxygen, water clarity , underwater grasses and chlorophyll

- a , an indicator of algae levels. It is importan t to note that the pollution controls employed to meet the TMDL will also have significant benefits for water quality in the tens of thousands of streams, creeks and rivers throughout the region. EPA will establish the final Chesapeake Bay TMDL, after cons idering public comments and additional input from the jurisdictions, by December 31, 2010.

Developing the Chesapeake Bay TMDL Development of the Chesapeake Bay TMDL required know ledge of the stream flow

characteristics of t he watershed, sources of polluti on, distribution and acrea ge of the various land

uses, approp riate best management practices, the transport and fate of pollutants, precipitation data and many other factors. The TMDL uses a series of models, calibrated to decades of water quality and other data, and refined based on input from dozens of Chesapeake Bay scientists. Modeling is an approach that uses observed and simulated data to replicate what is occur ring in

t he environment, and was a critical and valuable tool to develop the Chesapeake Bay TMDL.

The development of the TMDL consisted of three major steps.

1. EPA provided allocations to the jurisdictions and major basins for nitrogen, phosphorus

and sediment.

2. Ju risdictions developed draft Phase 1 Watershed Implementation Plans to achieve those

basin

- jurisdiction allocations. In these WIPs, jurisdictions made decisions on how to

further sub

- allocate the basin

- jurisdiction loadings to various individual point sourc es and a number of point and nonpoint source sectors.

3. EPA evaluated the draft WIPs and where deficiencies existed, EPA provided backstop allocations in the draft TMDL that consisted of a hybrid of the jurisdiction WIP allocations modified by EPA allocation s for some source sectors to fill gaps in the WIPs.

These draft TMDL loadings to the basin

- jurisdictions are provided in table ES

- 1. These loadings were determined using the best peer

- reviewed science and through extensive collaboration with the jurisdict ions and informed by the Watershed Implementation Plans.DRAFT Chesapeake Bay TMDL

v September 24

, 2010

Table ES

- 1. Chesapeake Bay TMDL watershed nutrient and sediment draft allocations by jurisdiction and by major river basin [proposed standards]

Jurisdiction Basin Nitrogen draft
allocations (milli on lbs/year) Phosphorus

draft allocations (million lbs/year) Sediment draft

allocations ( m illion lbs /year)

Pennsylvania Susquehanna 71.74 2.31 1,758.20

Potomac 4.72 0.42 233.93

Eastern Shore 0.28 0.01 21.12

Western Shore 0.02 0.001 0.37

PA Total 76.77 2.74 2,013.62

Maryland Susquehanna 1.08 0.05
62.94

Eastern Shore 9.71 1.09 169.70

Western Shore 9.74 0.46 170.38

Patuxent 2.85 0.21 90.12

Potomac 15.70 0.90 682.33

MD Total 39.09 2.72 1,175.47 Virginia Eastern Shore 1.21 0.16 10.91

Potomac 17.46 1.47 810.07 Rappahannock 5.84 0.90 688.51

York 5.41 0.54 107.09

James 23.48 2.34 852.77

VA Total 53.40 5.41 2,469.35

District of Columbia Potomac 2.32 0.12 11.16

DC Total 2.32 0.12 11.16

New York Susquehanna 8.23 0.52 292.96

NY Total 8.23 0.52 292.96

Delaware Eastern Shore 2.95 0.26 57.82

DE Total 2.95 0.26 57.82 West Virginia Potomac 4.67 0.74 248.11

James 0.02 0.01 16.65

WV Total 4.68 0.75 264.76

Total Basin/Jurisdiction Draft Allocation 187.44 12.52 6,285.14
Atmospheric Deposition Draft Allocation 15.70

-- -- Total Basinwide Draft Allocation 203.14 12.52 6,285.14

a. Cap on atmospheric deposition loads direct to Chesapeake Bay and tidal tributary surface waters to be achieved by federal air regulations through 2020.

Since nitrogen and phosphorus loadings from all parts of the Bay watershed have an impact on most segments of the Bay, it was necessary for EPA to allocate the nitrogen and phosphorus loadings in an equit able manner to the states and basins. There were 3 basic guides that were

used to divide these loads.DRAFT Chesapeake Bay TMDL

vi September 24

, 2010

A l located loads should protect living resources of the Bay and its tidal tributaries and result in all segments of the Bay mainstem, tidal tributaries and embayments meeting water quality standards for dissolved oxygen, chlorophyll a, water clarity and underwater

grasses. Tributary ba sins that contribute the most to the Bay water quality problems must do the most to resolve those problems (on a pound per pound basis). All tracked and reported reductions in nitrogen, phosphorus and sediment loads are credited toward achieving final assi gned loads.

In addition, EPA is committing to reducing air deposition of nitrogen to the tidal waters of the Chesapeake Bay to 15.7 million pounds per year. The reductions will be achieved through implementation of federal air regulations during the comi ng years.

To insure that these pollutant loadings will attain and maintain water quality standards, the TMDL calculations were developed to account for critical environmental conditions a waterway

would face , future growth, and seasonal variation. An impl icit margin of safety was also

included in the TMDL

.

The TMDL is designed to ensure that by 2025 all practices necessary to fully restore the Bay and its tidal river are in place, with 60 per cent of the actions taken by 2017. As mentioned above, a TMDL must be based on achieving established state water quality standards. In the case of the Bay TMDL, as the TMDL is being developed, the state water quality standards are being proposed for modification. So the loadings allocated to the states as

identified above and the state WIPs are based on loadings to achieve the proposed state
standards.

However, the Chesapeake Bay TMDL document also provides allocations for attaining the current water quality standards. In order to achieve the current standards, the allocations happen to be more stringent that the allocations identified above. This set of TMDL allocations are important if the state standards are not modified before the completion of the Bay TMDL.

Furthermore, this TMDL provides information on the po llution control levels for a full backstop TMDL, in case such controls are needed in the final TMDL.

EPA expects that the water quality standards and state WIPs are likely to change before this TMDL is finalized. So offering information on possible TMDL loadings under each of these options provides EPA with the flexibility, informed by the final WIPs and public comment, to

finalize this TMDL based on the relevant information at the time the TMDL is finalized. And the final TMDL allocations could range fro m full WIP based loads to full backstop loads, depending on the strength of the final state WIPs.

Accountability and Goals The Chesapeake Bay TMDL is unique because of the extensive measures included to ensure accountability for reducing pollution and meeting deadlines for progress. T he TMDL will be implemented using an accountability framework that includes W atershed Implementation Plans (WIPs), two

- year milestones, EPA‘s tracking and assessment of restoration progress and, asDRAFT Chesapeake Bay TMDL

vii September 24

, 2010

necessary, specific fede ral backstop actions if the jurisdictions do not meet their commitments. The accountability framework is being established in part to provide demonstration of the reasonable assurance provisions of the Chesapeake Bay TMDL pursuant to both the Clean Water

A ct and the Chesapeake Bay Executive Order, but i s not part of the TMDL itself.

When EPA establishes or approves a TMDL that allocates pollutant loads to both point and nonpoint sources, it determines whether there is a ―reasonable assurance‖ that the non point source load allocations will be achieved and water quality standards will be attained. Reasonable assurance for the Chesapeake Bay TMDL is provided by the numerous federal, state and local regulatory and non

- regulatory programs identified in the acco untability framework that EPA believes will result in the necessary point and nonpoint source controls and pollutant reduction programs. The most prominent program is the CWA‘s National Pollutant Discharge Elimination System (NPDES) permit program that reg ulates point sources throughout the nation. Many nonpoint sources are not covered by a similar federal permit program; as a result, financial incentives and other voluntary programs are used to achieve nonpoint source reductions. These

federal tools are su pplemented by a variety of state regulatory and voluntary programs and other commitments of the federal government set forth in the Executive Order s trategy and identified in the accountability framework discussed above.

Beginning in 2012, j urisdictions ( including the federal government) are expected to develop two

year milestones to track progress toward reaching the TMDL‘s goals

. In addition, the milestones

will demonstrate the effectiveness of the jurisdictions‘ WIPs by identifying specif ic near

- term

p ollutant reduction controls and a schedule for implementation (see next section for further description of WIPs). EPA will review these two

- year milestones and evaluate whether they are sufficient to achieve necessary pollution reductions and, through the use of a Bay Tracking and

Accounta bility System, determine if milestones are met.

If a jurisdiction‘s plans are inadequate or its progress is insufficient, EPA can invoke a suite of backstop actions to ensure pollution redu ctions. These include expanding coverage of NPDES permits to sources that are currently unregulated, increasing oversight of state

- issued NPDES permits, requiring additional pollution reductions from point sources such as wastewater treatment plants, increasing federal enforcement and co mpliance in the watershed, prohibiting new or expanded pollution discharges, redirecting EPA grants, and revising water quality standards to better protect local and downstream waters.

Watershed Implementation Plans The cornerstone of the accountability framework is the jurisdictions‘ development of Watershed Implementation Plans (WIPs), which serve as roadmaps for how and when a jurisdiction plans to

m eet its pollution allocations under the TMDL. In their draft Phase I WIPs, the jurisdictions were
expect ed to subdivide the Bay TMDL allocations among pollutant sources; evaluate their current legal, regulatory, programmatic and financial tools available to implement the allocations; identify and rectify potential shortfalls in attaining the allocations; des cribe mechanisms to track and report implementation activities; provide alternative appro aches; and outline a schedule f or implementation.DRAFT Chesapeake Bay TMDL

viii September 24

, 2010

EPA provided the jurisdictions with detailed expectations for WIPs in November 2009 and April

2010

. To assist with WIP preparation, EPA provided considerable technical and financial

assistance . Also last year, EPA announced target loads to allow the jurisdictions t o begin developing WIPs. EPA worked with the jurisdictions to evaluate various ―what if‖ scenarios

– combinations of practices and programs that could achieve their pollution allocations.

After the draft Phase I WIP submittal deadline of September 1, a team of EPA sector experts conducted an intense evaluation process, com paring the submissions with EPA expectations

. Two goals were p aramount in the EPA WIP review: achieving the basin

- jurisdiction pollution

allocations and providing a high level of assurance that reductions would be achieved, particularly for non

- permitted sources like runoff from agricult ural lands and currently unregulated stormwater from urban and suburban lands.

The EPA evaluation concluded that the pollution controls identified in two of the seven jurisdictions‘ WIPs could meet nitrogen and phosphorus allocations and five of the seven jurisdictions‘ WIPs could meet sediment allocations for the jurisdiction as a whole. The evaluation by jurisdiction is: Maryland: Some deficiencies

– Meets overall statewide allocations for n itrogen (at allocation), phosphorus (at allocation) and sediment (0 percent under)

, but several

individual river basins exceed the allocations for nitrogen, phosphorus or sediment

. District of Columbia: Some deficiencies

– Meets allocation for nitrogen (5 percent under) and phosphorus (3 percent under), but does not me et the sediment allocation (25 percent over).

Delaware: Serious deficiencies

– Does not meet allocations for nitrogen (17 percent over) and phosphorus (8 percent over), but does meet allocations for sediment (20 percent under).

New York: Serious deficienci es

– Does not meet allocations for nitrogen (15 percent over) and phosphorus (14 percent over), but does meet allocations for sediment (17 percent under. Pennsylvania: Serious deficiencies

– Does not meet allocations for nitrogen (0 percent under) and phos phorus (11 percent over), but does meet allocations for sediment (1 percent over). Virginia: Serious deficiencies

– Does not meet allocations for nitrogen (6 percent over) and phosphorus (7 percent over), but does meet allocations for sediment (12 percent under). West Virginia: Serious deficiencies

– D oes not meet allocation for nitrogen (18 percent over) or sediment (38 percent over), but does meet the allocation for phosphorus (6 percent under).

The EPA evaluation also concluded that n one of the seven WIPs provided sufficient reasonable

assurance that pollution controls i dentified could actually be implemented to achieve the nitrogen, phosphorus and sediment reduction targets by 2017 or 2025. The shortfalls of the WIPs, which varied by jurisdiction, inc luded: Vague or n o strategy for filling recognized program or resources gaps Few enforceable or otherwise binding commitmentsDRAFT Chesapeake Bay TMDL

ix September 24

, 2010

Discrepancies between implementation levels in model input decks and strategies

described in WIP

Reliance on pollution trading pro grams but no commitment to adopt critical trading drivers such as new regulations Few dates for key actions and program

- building milestones

EPA Backstop Allocations

Once EPA evaluated a WIP and found shortfalls in pollution loading reductions and/or assur ance that reductions would be achieved, EPA included only the parts of the WIP that it determined to be adequate and appropriate in its TMDL allocation. EPA then determined h ow to make up that

shortfall and/or insufficient amount of reasonable assurance fo r the remainder of the allocation. EPA considered varying levels of federal backstop allocations that adjusted loads delivered to the Bay to ensure water quality standards are met. The result is a draft TMDL that merge s jurisdictions‘ WIP allocations with varying degree s of federal backstop allocations in all seven jurisdictions, as well identification of additional federal a ctions that EPA is pr epared to take if jurisdictions do not achieve milestones on schedule

. For the most part in making the hybrid

all ocations, EPA decreased the allocations to the point sources (over which EPA has or could assert regulatory control) and increased the load allocations to unregulated nonpoint sources.

EPA identified b ackst op allocations at three levels:

Minor: EPA adjuste d WIP pollution sector allocations to achieve the jurisdiction‘s overall and major river basin nitrogen, phosphorus and sediment allocations.

Moderate: WIP aggregate point source allocations for stormwater and animal agriculture (CAFO) sectors were adjusted to equate to the best approach that was proposed and determined adequate in other jurisdiction WIP s. More stringent wasteload allocations were applie d to point source wastewater sources (regulated via federal programs); other nonpoint source allocations increased as feasible if there was insufficient assurance that

reductions would be achieved. High: WIP aggregate allocations for point source stormwa ter and animal agriculture sectors were adjusted downward to equate to the best approach that was proposed and determined adequate in other jurisdiction WIP s; Very stringent wastewater allocations were applied to point source wastewater sources based on l i mit of tec hnology concentrations (regulated via federal programs); other nonpoint source allocations

increased as feasible if there was insufficient assurance that reductions would be

achieved.

Backstop allocations focus on areas where EPA has the federal authority to control pollution allocations through NPDES permits . These backstops involve substituting a j urisdiction‘s proposed point source allocations with more stringent EPA ―backstop allocations‖ for point

sources including wastew ater treatment plants, stormwater permits, and animal agriculture operations. The draft TMDL reflects the following level of backstops for each jurisdiction:

Maryland : Minor

- level backstop allocations primarily for Maryland‘s nonpoint source

load allocati ons to meet nitrogen, phosphorus and sediment allocations in each major basin within Maryland. No changes to point source wasteload allocations that would

affect NPDES permit conditions.DRAFT Chesapeake Bay TMDL

x September 24

, 2010

District of Columbia: Minor

- level backstop allocations to District of Columbia‘s wasteload allocations for urban stormwater so that the District meets upper range of

sediment allocation. EPA will ensure that all allocations , including sediment, are met through the NPDES permits issued within the District

.

Virginia: Mode rate

- level backstop allocations for Virginia point sources

o Wastewater treatment plants : 4 mg/L TN and .3 mg/L TP and design flow for significant municipal plants consistent with most aggressive WIP proposal (Maryland ENR Strategy).

o MS4s: 50 percent of urba n MS4 lands meet aggressive performance standard

thro ugh retrofit/ redevelopment; 50 percent of unregulated land t reated as regulated, so that 25 percent of unregulated land meets aggressive performance standard; designation as necessary

.

o Construction: Ero sion and sediment control on all lands subject to Construction

General Permit

.

o CAFO production areas: Waste management, barnyard runoff control, mortality composting. Precision feed management for all animals. Same standards apply to

AFOs no t subject to CAFO permit except no feed management on da iries; designation as necessary.

o Additional adjustments to agriculture nonpoint sources as necessary to exactly

meet nitrogen, phosphorus and sediment allocations

.

Delaware: High

- level backstop allocations for De laware point sources

o Wastewater treatment plants : limit of technology ( 3 mg/L TN and .1 mg/L TP ) and design flow for significant municipal plants

.

o MS4s: 50 percent of urban MS4 lands meet aggressive performance standard

thro ugh retrofit/ redevelopment; 50 percent of unregulated land t reated as regulated, so that 25 percent of unregulated land meets aggressive performance standard; designation as necessary

.

o Construction: Erosion and sediment control on all lands subject to Construction

General Permit

.

o CAFO production areas: Waste management, barnyard runoff control, mortality composting. Precision feed management for all animals. Same standards apply to

AFOs no t subject to CAFO permits except no feed management on dairies; designation as necessary.

o Additiona l reductions from agricultural nonpoint sources necessary to meet nitrogen and phosphorus al locations that EPA will ensure occurs through

addi tional federal backstop actions.

New York: High

- level backstop allocations for New York point sources

o Wastewater treatment plants: limit of technology (3 mg/L TN and .1 mg/L TP) and design flow for significant municipal plants.

o MS4s: 50 percent of urban MS4 lands meet aggressive performance standard through retrofit/ redevelopment; 50 percent of unregulated land trea ted as regulated, so that 25 percent of unregulated land meets aggressive performance standard; designation as necessary.DRAFT Chesapeake Bay TMDL

xi September 24

, 2010 o Construction: Erosion and sediment control on all lands subject to Construction

General Permit.

o CAFO production areas: Waste managemen t, barnyard runoff control, mortality composting. Precision feed management for all animals. Same standards apply to AFOs not subject to CAFO permits except no feed management on dairies; designation as necessary.

o Additional reductions from agricultural no npoint sources necessary to meet nitrogen, phosphorus and sediment allocations that EPA will ensure occurs through additional federal backstop actions.

o Finer scale wasteload and load allocations (same level of detail as tidal states) to ensure NPDES permi ts will be consistent with Chesapeake Bay TMDL wasteload

allocations.

Pennsylvania: High

- level backstop allocations for Pennsylvania point sources

o Wastewater treatment plants : limit of technology ( 3 mg/L TN and .1 mg/L TP ) and design flow for significant municipal plants

.

o MS4s: 50 percent of urban MS4 lands meet aggressive performance standard

throu gh retrofit/ redevelopment; 50 percent of unregulated land t reated as regulated, so that 25 percent of unregulated land meets aggressive performance standard; designation as necessary

.

o Construction: Erosion and sediment control on all lands subject to Construction

General Permit

.

o CAFO production areas: Waste management, barnyard runoff control, mortalit y composting. Precision feed management for all animals. Same standards apply to AFOs not subject to CAFO permits except no feed management on dairies;

de signation as necessary.

o Load from point source reductions redistributed to forest, septic, and agricul ture

sources as possible while still meet ing nitrogen, phosphorus and sediment

allocations

.

o Finer scale wasteload and load allocations (same level of detail as tidal states) to ensure NPDES permits will be consistent with Chesapeake Bay TMDL wasteload

allo cations

.

West Virginia: High

- level backstop allocations for West Virginia point sources

o Wastewater treatment plants: limit of technology (3 mg/L TN and .1 mg/L TP) and design flow for significant municipal plants.

o MS4s: 50 percent of urban MS4 lands meet aggressive performance standard through retrofit/ redevelopment; 50 percent of unregulated land treated as regulated, so that 25 percent of unregulated land meets aggressive performance standard; designation as necessary.

o Construction: Erosion and sediment control on all lands subject to Construction

General Permit.

o CAFO production areas: Waste management, barnyard runoff control, mortality composting. Precision feed management for all animals. Same standards apply to AFOs not subject to CAFO permits except no feed management on dairies; designation as necessary.DRAFT Chesapeake Bay TMDL

xii September 24

, 2010 o Additional reductions from agricultural nonpoint sources necessary to meet July 1 and August 13 nitrogen, phosphorus and sediment allocations that EPA will ensure occurs through additional federal b ackstop actions.

o Finer scale wasteload and load allocations (same level of detail as tidal states) to ensure NPDES permits will be consistent with Chesapeake Bay TMDL wasteload

allocations.

The jurisdictions are encouraged to revise and strengthen their draft Phase I WIPs before final

versions are due November 29 to meet the basin

- state pollution allocations and provide

reasonable assurance the allocations will be achieved

. During this time, EPA will engage jurisdictions to share best approaches from the WIPs across the jurisdictions and provide EPA

g uidan ce on the most effective pollution controls. When final Phase I WIPs are submitted, EPA will again evaluate the plans to determine if EPA backstop allocations can be replaced with sufficiently improved st ate commitments

.

In 2011, the jurisdictions are expected to submit Phase II WIPs that allocate the pollutant loads on a geographically smaller scale. Phase III WIPs in 2017 are expected to be designed to provide

additional detail of restoration actions b eyond 2017 and ensure that the 2025 goals are met.

Public Participation The release of the draft Chesapeake Bay TMDL on September 24, 2010 began a 45

- day public comment period that concludes on November 8, 2010. During the public comment period, there

are 18 public meetings in all six watershed states and the District. A full public meeting schedule, including registration links for an online broadcast in each jurisdiction, is available at http://www.epa.g ov/chesapeakebaytmdl . The website also provides a link for accessing and formally commenting on the draft TMDL.

The TMDL is available for viewing at EPA Region III

, 1650 Arch Street, Philadelphia, PA 19103 with arrangements made in advance with the Regio n 3 library (215

- 814

- 5254 or library

reg3@epa.gov), EPA Chesapeake Bay Program Office at 410 Severn Avenue Suite 112, Annapolis, MD 21403 (Contact Debbie Embleton 410

- 267

- 9856 or Embleton.debbie@epa.gov) or EPA Docket Center, EPA/DC, EPA West, Room 3334, 1 301 Constitution Ave., NW., Washington, DC (Docket Number EPA

- R03

- OW

- 2010

- 0736 and reading room phone number (202) 566

- 1744).

Options for comment are: Electronically, visit: www.regulations.gov

. Docket ID No. EPA

- R03

- OW

- 2010

- 0736 In writing, mail to: Water Docket, EPA, Mail code : 2822T, 1200 Pennsylvania Ave.

, NW., Washington, D.C., 20460. By hand, drop o ff from 8:30 a.m.

- 4:30 p.m.: EPA Dock et Center Public Reading Room,

EPA Headquarters West, R oom 3340, 1301 Constitution Ave., NW, Washington, D.C.DRAFT Chesapeake Bay TMDL

xiii September 24

, 2010 

## Contents

SECTION 1. Introduction

................................ ................................ ................................ ..... 1

- 1

1.1. TMDLs and the CWA

................................ ................................ ................................ ............ 1

- 2

1.2 History of the Chesapeake Bay TMDL

................................ ................................ ................. 1

- 3

1.2.1 Regulatory and Management Initiatives

................................ ................................ ............................ 1

- 3

1.2.2 Pa rtnership Commitment to Develop the Chesapeake Bay TMDL

................................ ................... 1

- 5

1.2.3 President‘s Chesapeake Bay Executive Order

................................ ................................ ................... 1

- 6

1.3 Bay TMDL Process, Partner Coordination and Responsibilities

................................ ....... 1

- 7

1.3.1 CBP Partnership and Organizational Structure

................................ ................................ .................. 1

- 8

1.4 Legal Framework for the Chesapeake Bay TMDL

................................ ........................... 1

- 11

1.4 .1. What is a TMDL?

................................ ................................ ................................ ................................ . 1

- 11 1.4.2. Why is EPA establishing this TMDL?

................................ ................................ ................................ . 1

- 12

SECTION 2. WATERSHED and Impairment Description

................................ ................. 2

- 1

2.1 Ge neral Watershed Setting

................................ ................................ ................................ .... 2

- 1

2.2 Chesapeake Bay TMDL Scope

................................ ................................ .............................. 2

- 7

2.2.1 Pollutants of Concern

................................ ................................ ................................ ......................... 2

- 8

2.2.2 Chesapeake Bay Program Segmentation Scheme

................................ ................................ .............. 2

- 8

2 .2.3 Jurisdictions‘ 2008 303(d) Listings

................................ ................................ ................................ . 2

- 15

2.2.4 2008 303(d) Listing Segments Compared to Consent Decree and MOU Segments

........................ 2

- 16

SECTION 3. Chesapeake Bay Water Quality Standards

................................ .................... 3

- 1

3.1 Chesapeake Bay Water Quality Criteria and Designated Uses

................................ .......... 3

- 1

3.1.1 Tidal Water Designated Uses

................................ ................................ ................................ ............. 3

- 4

3.1.2 Dissolved Oxygen Criteria

................................ ................................ ................................ ................. 3

- 9

3.1.3 Chlorophyll a Criteria

................................ ................................ ................................ ...................... 3

- 11

3.1.4 Water Clarity/Underwater Bay Grasses Criteria

................................ ................................ .............. 3

- 12

3.2 Jurisdictions’ Current Chesapeake Bay Water Quality Standards Regulations

........... 3

- 15

3.2.1 District of Columbia

................................ ................................ ................................ ........................ 3

- 16

3.2.2 Delaware

................................ ................................ ................................ ................................ .......... 3

- 17

3.2.3 Maryland

................................ ................................ ................................ ................................ .......... 3

- 17

3.2.4 Virginia

................................ ................................ ................................ ................................ ............ 3

- 17

3.3 Jurisdictions’ Pending Revisions to Chesapeake Bay Water Quality Standards Regulations

................................ ................................ ................................ ................................ ......... 3

- 18

3.3.1 District of Columbia

................................ ................................ ................................ ........................ 3

- 18

3.3.2 Delaware

................................ ................................ ................................ ................................ .......... 3

- 18

3.3.3 Maryland

................................ ................................ ................................ ................................ .......... 3

- 18

3.3.4 Virginia

................................ ................................ ................................ ................................ ............ 3

- 19

3.4 Assessing Attainment of Chesapeake Bay Water Quality Standards

.............................. 3

- 19

3.4.1 Defining Total Exceedances

................................ ................................ ................................ ............ 3

- 19

3.4.2 Defining Allowable Exceedances

................................ ................................ ................................ .... 3

- 21

3.4.3 Assessin g Criteria Attainment

................................ ................................ ................................ ......... 3

- 23

SECTION 4. Sources of Nutrients and Sediment to the Chesapeake Bay

......................... 4

- 1

4.1 Jurisdiction Loading Contributions

................................ ................................ ...................... 4

- 1DRAFT Chesapeake Bay TMDL

xiv September 24

, 2010

4.2 Major River Basin Contributions

................................ ................................ ......................... 4

- 3

4.3 Pollutant Source Sector Contributions

................................ ................................ ................. 4

- 6

4.4 Regulated Point Sources

................................ ................................ ................................ ........ 4

- 7

4.4.1 Significant and Nonsignificant Municipal and Industrial Facilities

................................ ................... 4

- 8

4.4.2 Basinwide NPDES Permitting Approach

................................ ................................ .......................... 4

- 9

4.4.3 Data Sources

................................ ................................ ................................ ................................ .... 4

- 10

4.5 Regulated Point Source Load Summaries

................................ ................................ .......... 4

- 12

4.5.1 Municipal Wastewater Discharging Facilities

................................ ................................ ................. 4

- 13

4.5.2 Industrial Discharge Fa cilities

................................ ................................ ................................ ......... 4

- 17

4.5.3 Combined Sewer Overflows

................................ ................................ ................................ ............ 4

- 21

4.5.4 Sanitary Sewer Overflows

................................ ................................ ................................ ............... 4

- 24

4.5.5 NPDES Permitted Stormwater

................................ ................................ ................................ ......... 4

- 24

4.5.6 Concentrated Animal Feeding Operations

................................ ................................ ....................... 4

- 28

4.6 Nonpoint Sources

................................ ................................ ................................ .................. 4

- 30

4.6.1 Data Sources

................................ ................................ ................................ ................................ .... 4

- 30

4.7 Nonpoint Source Load Summaries

................................ ................................ ..................... 4

- 31

4.7.1 Agriculture

................................ ................................ ................................ ................................ ....... 4

- 31

4.7.2 Atmospheric Deposition

................................ ................................ ................................ .................. 4

- 35

4.7.3 Forest Lands

................................ ................................ ................................ ................................ ..... 4

- 39

4.7.4 On

- site Wastewater Treatment Systems

................................ ................................ .......................... 4

- 39

4.7.5 Nonregulated Stormwater Runoff

................................ ................................ ................................ .... 4

- 41

4.7.6 Oceanic inputs

................................ ................................ ................................ ................................ . 4

- 41

4.7.7 Streambank and Tidal Shoreline Erosion

................................ ................................ ......................... 4

- 43

4.7.8 Tidal Resuspension

................................ ................................ ................................ .......................... 4

- 45

4.7.9 Wildlife

................................ ................................ ................................ ................................ ............ 4

- 46

4.7.10 Natural Background

................................ ................................ ................................ .................... 4

- 46

SECTION 5. Chesapeake Bay Monitoring and Modeling Frameworks

............................ 5

- 1

5.1 Technical Monitoring and Modeling Requirements

................................ ........................... 5

- 1

5.2 Bay Monitoring Framework Overview

................................ ................................ ................ 5

- 2

5.2.1 Partnership‘s Chesapeake Bay Tidal Monitoring Network

................................ ................................ 5

- 2

5.2.2 Partnership‘s Watershed Monitoring Network

................................ ................................ .................. 5

- 8

5.2.3 Data Quality and Access

................................ ................................ ................................ .................. 5

- 11

5.2.4 Data Submission and Quality Assurance

................................ ................................ ......................... 5

- 12

5.2.5 Monitoring Applications in Chesapeake Bay TMDL Develop ment

................................ ................ 5

- 15

5.3 Modeling Framework Overview

................................ ................................ ......................... 5

- 15

5.4 Chesapeake Bay Airshed Model

................................ ................................ .......................... 5

- 17

5.5 Chesapeake Bay Land Change Model

................................ ................................ ................ 5

- 20

5.5.1 Motivations for Developing Future Land Use Estimates

................................ ................................ . 5

- 20

5.5.2 Scale of Chesapeake Bay Land Change Model Future Land Use Estimates

................................ ... 5

- 21

5.5.3 Components of Chesapeake Bay Land Change Model Future Land Use Estimates

........................ 5

- 23

5.6 Chesapeake Bay SPARROW Model

................................ ................................ ................... 5

- 24

5.7 Scenario Builder

................................ ................................ ................................ ................... 5

- 26

5.8 Phase 5 Chesapeake Bay Watershed Model

................................ ................................ ....... 5

- 27

5.8.1 Segmentation

................................ ................................ ................................ ................................ ... 5

- 29

5.8.2 Model Setup

................................ ................................ ................................ ................................ ..... 5

- 2 9

5.8.3 Pollutant Source Representation

................................ ................................ ................................ ...... 5

- 34DRAFT Chesapeake Bay TMDL

xv September 24

, 2010

5.8.4 Calibration

................................ ................................ ................................ ................................ ....... 5

- 35

5.9 Chesapeake Bay Water Quality and Sediment Transport Model

................................ .... 5

- 37

5.9.1 Nonpoint Source Loads

................................ ................................ ................................ ................... 5

- 39

5.9.2 Point Source Loads

................................ ................................ ................................ .......................... 5

- 39

5.9.3 Atmospheric Loads

................................ ................................ ................................ .......................... 5

- 39

5.9.4 Bank Loads

................................ ................................ ................................ ................................ ...... 5

- 39

5.9.5 Wetlands

................................ ................................ ................................ ................................ .......... 5

- 39

5.9.6 Model Setup

................................ ................................ ................................ ................................ ..... 5

- 39

5.10 CHESAPEAKE BAY CRITERIA ASSESSMENT PROGRAM

................................ .......... 5

- 40

5.11 CLIMATE CHANGE SIMULATION

................................ ................................ .................... 5

- 41

SECTION 6. Chesapeake Bay TMDL Development

................................ ........................... 6

- 1

6.1 Establishing Model Parameters

................................ ................................ ............................ 6

- 1

6.1.1 Hydrologic Period

................................ ................................ ................................ .............................. 6

- 1

6.1.2 Critical Conditions

................................ ................................ ................................ ............................. 6

- 3

6.1.3 Water Quality Standards

................................ ................................ ................................ .................... 6

- 4

6.1.4 Seasonal Variation

................................ ................................ ................................ ............................. 6

- 5

6.2 Interpreting Model Results

................................ ................................ ................................ .... 6

- 7

6.2.1 Criteria Assessment Procedures

................................ ................................ ................................ ......... 6

- 7

6.2.2 Addressing Reduced Sensitivity to Load Reductions at Low Nonattainment Percentages

............... 6

- 9

6.2.3 Mar gin of Safety

................................ ................................ ................................ .............................. 6

- 12

6.2.4 Temporary Reserve

................................ ................................ ................................ .......................... 6

- 14

6.2.5 Daily Loads

................................ ................................ ................................ ................................ ...... 6

- 15

6.3 Establishing Allocation Rules

................................ ................................ .............................. 6

- 18

6.3.1 Nutrient Allocation Methodology

................................ ................................ ................................ .... 6

- 18

6.3.2 Sediment Allocation Methodology

................................ ................................ ................................ .. 6

- 29

6.4 Assessing Attainment of Proposed Amended Chesapeake Bay WQS

............................. 6

- 30

6.4.1 Establishing Nutrient Load Caps to Attain the Proposed Amended Water Quality Standards

........ 6

- 30

6.4.2 Determining the Sediment Load Caps to Achieve the Proposed Amended Water Quality Standards

. 6

- 46

6.5 Assessing Attainment of Current WQS

................................ ................................ .............. 6

- 50

6.5.1 Establishing Nutrient Basin

- Jurisdiction Load Caps

................................ ................................ ....... 6

- 50

6.5.2 Establishing Sediment Load Caps

................................ ................................ ................................ ... 6

- 53

6.6 Setting Draft Basin

- jurisdiction Allocations

................................ ................................ ...... 6

- 54

6.6.1 Basin

-

jurisdiction Allocations to Achieve the Proposed WQS

................................ ........................ 6

- 54

6.6.2 Basin

-

jurisdiction Al locations to Achieve the Current WQS

................................ .......................... 6

- 56

SECTION 7. Reasonable Assurance and Accountability Framework

................................ 7

- 1

7.1 Reasonable Assurance

................................ ................................ ................................ ............ 7

- 1

7.2 Accountability Framework

................................ ................................ ................................ .... 7

- 4

7.2.1 Watershed Implementation Plans

................................ ................................ ................................ ...... 7

- 5

7.2.2 Two

- Year Milestones

................................ ................................ ................................ ........................ 7

- 8

7.2.3 Chesapeake Bay TMDL Accountability Tracking System

................................ ................................ 7

- 9

7.2.4 Federal EPA Actions

................................ ................................ ................................ ...................... 7

- 11DRAFT Chesapeake Bay TMDL

xvi September 24

, 2010

SECTION 8. WATERSHED IMPLEMENTATION PLAN EVALUATION AND DRAFT

BACKSTOP ALLOCATIONS

................................ ................................ ................................ .... 8

- 1

8.1 WIP Evaluation Methodology

................................ ................................ ................................ . 8

- 2

8.2 WIP Evaluation Results

................................ ................................ ................................ .......... 8

- 4

8.2.1 Target Nutrient/Sediment Allocation Gaps

................................ ................................ ........................ 8

- 5

8.2.2 Insufficient Reasonable Assurance

................................ ................................ ................................ .... 8

- 6

8.2.3 Summary of Results of EPA Evaluation of Draft Phase I WIPs

................................ ........................ 8

- 7

8.3 Draft Backstop Allocations

................................ ................................ ................................ ...... 8

- 8

8.3.1 Methodology for Backstop Allocations

................................ ................................ ............................. 8

- 9

8.3.2 Assumptions Supporting the Draft Bay TMDL Backstop Allocations

................................ ........... 8

- 12

8.3.3 Summary of Backstop Allocations

................................ ................................ ................................ .. 8

- 17

SECTION 9. Chesapeake Bay TMDLs

................................ ................................ ................ 9

- 1

9.1 Bay Segment Annual and Daily Allocations to Meet Proposed Amended WQS

.............. 9

- 1

9.2 Bay Segment Annual and Daily Allocations to Meet Current WQS

............................... 9

- 42

SECTION 10. TMDL Implementation and Adaptive Management

................................ .... 10

- 1

10.1 Future Growth

................................ ................................ ................................ ...................... 10

- 1

10.1.1 Designating Target Loads for New or Increased Sources

................................ ........................... 10

- 1

10.1.2 Offset Programs

................................ ................................ ................................ .......................... 10

- 1

10.1.3 Additional Offset Program Features

................................ ................................ ........................... 10

- 2

10.1.4 EPA‘s Oversight Role of State Offset Program

................................ ................................ .......... 10

- 3

10.2 Water Quality Trading

................................ ................................ ................................ ........ 10

- 3

10.3 Future Modifications to the Chesapeake Bay TMDL

................................ ....................... 10

- 4

10.4 Federal Facilities and Lands

................................ ................................ ................................ 10

- 5

10.5 Factoring in Effects from Continued Climate Change

................................ ..................... 10

- 7

10.6 Sediments behind the Susquehanna River Dams

................................ .............................. 10

- 7

10.7 Filter Feeders

................................ ................................ ................................ ........................ 10

- 8

SECTION 11. Public Participation

................................ ................................ ...................... 11

- 1

11.1 Stakeholder and Local Government Outreach and Involvement

................................ .... 11

- 1

11.1.1 Open Collaboration with Stakeholders

................................ ................................ ....................... 11

- 1

11.1.2 Outreach to Local Governments and Elected Officials

................................ ............................... 11

- 1

11.1.3 Local Pilots

................................ ................................ ................................ ................................ . 11

- 2

11.2 Public Outreach

................................ ................................ ................................ .................... 11

- 2

11.2.1 Public Meetings

................................ ................................ ................................ .......................... 11

- 2

11.2.2 Webinars to Expand Audiences

................................ ................................ ................................ .. 11

- 4

11.2.3 Chesapeake Bay TMDL Web Site

................................ ................................ .............................. 11

- 4

11.2.4 Public Notices

................................ ................................ ................................ ............................. 11

- 5

11.3 Responses to Pu blic Comments

................................ ................................ ........................... 11

- 5

SECTION 12. References

................................ ................................ ................................ ..... 12

- 1DRAFT Chesapeake Bay TMDL

xvii September 24

, 2010

SECTION 13. Glossary

................................ ................................ ................................ ......... 13

- 1

SECTION 14. Abbreviations

................................ ................................ ................................ . 14

- 1



### Appendices

Appendix A Chesapeake Bay TMDL Contributors

Appendix B Index of Documents Supporting the Chesapeake Bay TMDL

Appendix C Record of Chesapeake Bay TMDL Related Chesapeake Bay Program Committee,

Team and Workgroup and Partner/Stakeholder Meetings

Appendix D Evaluation of the Most Protective Chesapeake Bay Dissolved Oxygen Criteria

Appendix E Summary of Initial Climate Chang e Impacts on the Chesapeake Bay Watershed

Flows and Loads

Appendix F Determination of the Hydrologic Period for Model Application

Appendix G Determination of Critical Conditions for the Chesapeake Bay TMDL

Appendix H Criteria Assessment Procedures using Model Scenario Output with Bay

Monitoring Data

Appendix I Documentation of the Reduced Sensitivity to Load Reductions at Low

Nonattainment Percentages

Appendix J Key Chesapeake Bay TMDL Reference and Management Model Scenarios:

Definitions and Descriptions

Appendix K Allocation Methodology for Relating Relative Impact to Needed Controls

Appendix L Setting the Chesapeake Bay Atmospheric Nitrogen Deposition Allocations

Appendix M Chesapeake Bay Water Quality/Sediment Transport Model Management Scenario

Attainment Assessment Results and 2008 303(d) Chesapeake Bay List

Assessment Results

Appendix M

- 1 Chesapeake Bay Dissolved Oxygen Criteria Attainment

Assessment Results

Appendix M

- 2 Chesapeake Bay Chlorophyll a Criteria Attainment

Assessment Resul ts

Appendix M

- 3 Chesapeake Bay Water Clarity/SAV Criteria Attainment

Assessment Results

Appendix M

- 4 Chesapeake Bay Segments 2008 303(d) List Assessment

Results

Appendix N Resolution of Segments Failing to Attain the Applicable Criteria

Appendix N

- 1 Resol ution of Segments Failing to Attain the Dissolved

Oxygen CriteriaDRAFT Chesapeake Bay TMDL

xviii September 24

, 2010 Appendix N

- 2 Resolution of Segments Failing to Attain the SAV/Water

Clarity Criteria

Appendix O Setting the Chlorophyll a Criteria

- Based Nutrient Allocations for the James River

Watershed

A ppendix P Setting the Water Clarity/SAV Criteria

- Based Sediment Allocations

Appendix Q Detailed Annual Chesapeake Bay TMDL WLAs and LAs

Appendix R Chesapeake Bay TMDL Daily WLAs and LAs

Appendix S Offsets for New or Increased Loadings of Nitrogen, Phosphorus and Sediment to

the Chesapeake Bay Watershed

Appendix T Sediments behind the Susquehanna Dams Technical Documentation

Appendix U Accounting for the Benefits of Filter Feeder Restoration Technical

Documentation

Appendix V Responses to Public C omments Received on the September 24, 2010

, Draft

Chesapeake Bay TMDLDRAFT Chesapeake Bay TMDL

xix September 24

, 2010 

## Tables

Table 1

- 1. URLs for accessing the seven Chesapeake Bay watershed jurisdictions‘ tributary strategies

................................ ................................ ................................ ................................ ...... 1

- 4

Table 1

- 2. Summary of Ch esapeake Bay TMDL relevant actions agreed to by the CBP‘s Principals‘ Staff Committee during its October 1, 2007, meeting

................................ ............... 1

- 6

Table 1

- 3. Virginia consent decree (CD) waters impaired for dissolved oxygen (DO) and/or

nutrients that w ill be addressed by the Chesapeake Bay TMDL

................................ ............... 1

- 15

Table 1

- 4. District of Columbia consent decree (CD) waters impaired for pH that will be addressed by the Chesapeake Bay TMDL

................................ ................................ ................. 1

- 16

Table 2

- 1 . The Chesapeake Bay 303(d) tidal segments with consent decree (CD)/memorandum of understanding (MOU) and 303(d) listing status by major river basin and jurisdiction

......... 2

- 10

Table 2

- 2. Comparison of consent decree/MOU segments with tot al number of Bay segments

.. 2

- 16

Table 3

- 1. Chesapeake Bay water quality criteria and designated use related documentation and

addenda

................................ ................................ ................................ ................................ ........ 3

- 2

Table 3

- 2. Five Chesapeake Bay tidal waters designated uses

................................ .................... 3

- 4

Table 3

- 3. Current tidal water designated uses by Chesapeake Bay segment

............................. 3

- 6

Table 3

- 4. Current Chesapeake Bay DO criteria

................................ ................................ ....... 3

- 11

Table 3

- 5. Summary of Chesapeake Bay water clarity criteria for application to shallow

- water bay grass designated use habitats

................................ ................................ ............................... 3

- 12

Table 3

- 6. Chesapeake Bay SAV restoration acreages and application depths

— current WQS 3

- 13

Table 3

- 7. Links for accessing the current WQS regulations for Delaware, the District of Columbia, Maryland, and Virginia

................................ ................................ ............................ 3

- 16

Table 3

- 8. District of Columbia designated uses for surface waters

................................ ......... 3

- 16

Table 3

- 9. Numeric criteria for the District of Columbia‘s tidally influenced waters

............... 3

- 16

Table 3

- 10. Segment

- specific chlorophyll a criteria for Virginia‘s tidal James River waters

.. 3

- 18

Table 3

- 11. Estimated perc ent spatial criteria exceedances and associated cumulative probabilities

................................ ................................ ................................ ................................ 3

- 20

Table 4

- 1. Percentage of total nitrogen from each major pollutant source sector by jurisdiction 4

- 6

Table 4

- 2. Percentage of total phosphorus from each major pollutant source sector by jurisdiction

................................ ................................ ................................ ................................ ...................... 4

- 6

Table 4

- 3. Percentage of sediment from each source sector by jurisdiction

............................... 4

- 7

Table 4

- 4. Jurisdiction

- specific definitions of significant municipal and industrial wastewater discharge facilities

................................ ................................ ................................ ....................... 4

- 8

Table 4

- 5. Significant and nonsignificant municipal and industrial wastewater discharging facilities by jurisdiction

................................ ................................ ................................ ................ 4

- 8

Table 4

- 6. Nutrient permit tracking summary under the Basinwide NPDES Wastewater Permitting Approach, through June 2010

................................ ................................ .................. 4

- 10

Table 4

- 7. Municipal wastewater facilities by jurisdiction

................................ ........................ 4

- 13

Table 4

- 8. Model estimated 2009 municipal wastewater loads by jurisdiction delivered to Chesapeake Bay

................................ ................................ ................................ ......................... 4

- 13

Table 4

- 9. Model estimated 2009 municipal wastewater loads by major r iver basin delivered to Chesapeake Bay

................................ ................................ ................................ ......................... 4

- 14

Table 4

- 10. Industrial wastewater facilities

................................ ................................ ............... 4

- 17

Table 4

- 11. 2009 Load estimates of industrial facility discharges

................................ ............ 4

- 17DRAFT Chesapeake Bay TMDL

xx September 24

, 2010

Table 4

- 12. 2009 Flow, total nitrogen, and total phosphorus load estimates of industrial

wa stewater facility discharges by major river basin

................................ ................................ .. 4

- 18

Table 4

- 13. Combined sewer system communities in the Bay watershed

................................ . 4

- 21

Table 4

- 14. NPDES stormwater permittees by jurisdiction and in the Chesapeake Bay watershed,

summer 2009

................................ ................................ ................................ .............................. 4

- 27

Table 4

- 15. Federal numeric thresholds for small, medium, and large CAFOs

........................ 4

- 28

Table 4

- 16. Estimated number of state or federal permitted CAFOs

................................ ........ 4

- 30

Table 4

- 17. Estimated portion of deposited NOx loads on the Chesapeake watershed from four

source sectors

— EGUs, mobile sources , industry, and all other sources in 1990 and 2020

...... 4

- 38

Table 4

- 18. Chesapeake Bay WQSTM simulated SAV acres under a range of sediment scoping scenarios compared with the 2010 Tributary Strategy scenario

................................ ................ 4

- 46

Table 5

- 1. Modeling tools supporting developmen t of the Chesapeake Bay TMDL.

............... 5

- 16

Table 5

- 2. Phase 5.3 Chesapeake Bay Watershed Model land uses

................................ .......... 5

- 30

Table 6

- 1. Tributary strategy and proposed amended Bay WQS

- based allocation scenarios TSS loads (millions of pounds) by jurisdiction

................................ ................................ ................... 6

- 8

Table 6

- 2. Differ ent approaches available under the explicit and implicit MOS types

............. 6

- 13

Table 6

- 3. Nitrogen and phosphorus temporary reserves by Chesapeake Bay watershed jurisdiction.

................................ ................................ ................................ ................................ 6

- 15

Table 6

- 4. Annual/Daily Maximum (ADMs) for calculating daily maximum loads

- ............... 6

- 17

Table 6

- 5. Relative effectiveness (measured as DO concentration per edge

- of

- stream pound reduced) for nitrogen and phosphorus for watershed jurisdictions by major river basin and above

and below the fall line

................................ ................................ ................................ ................ 6

- 21

Table 6

- 6. Pollutant sources as defined fo r the No Action and E3 model scenarios

................. 6

- 27

Table 6

- 7. Chesapeake Bay designated use segments showing percent nonattainment of the applicable Bay DO WQS under the proposed basinwide nutrient target loadings (shaded column)

................................ ................................ ................................ ................................ .................... 6

- 37

Table 6

- 8. Percent nonattain ment of the current Chesapeake SAV

- water clarity WQS for the Back, Chester and middle Pocomoke (Maryland) rivers under a range of nutrient and sediment

reduction load scenarios

................................ ................................ ................................ ............. 6

- 54

Table 6

- 9. Chesapeake Bay watershed nutrient and sediment draft allocation s by major river basin by jurisdiction to achieve the proposed Chesapeake Bay WQS.

................................ ...... 6

- 55

Table 6

- 10. Chesapeake Bay watershed nutrient and sediment draft allocations by jurisdiction by major river basin to achieve the proposed Chesapeake Bay WQS.

................................ ........... 6

- 56

Table 6

- 11. Chesapeake Bay Allocations for Existing WQS by Jurisdiction

............................ 6

- 58

Table 7

- 1. Eight elements of the jurisdictions‘ WIPs

................................ ................................ .. 7

- 6

Table 7

- 2. Comparison of elements within the Chesapeake Bay TMDL and Phase I, II, and III

WIPs

................................ ................................ ................................ ................................ ............. 7

- 7

Table 8

- 1. Thresholds for fo ur evaluation tiers for assessing whether a jurisdiction met its nitrogen, phosphorus, and sediment target allocations

................................ ................................ 8

- 3

Table 8

- 2. Thresholds for the four Phase I WIP evaluation tiers for the reasonable assurance

assessment

................................ ................................ ................................ ................................ .... 8

- 4

Table 8

- 3. Comparison of the nitrogen, phosphorus, and sediment jurisdiction

- wide allocations in the jurisdictions‘ draft Phase I WIPs with the target allocations for each pollutant

.................... 8

- 5

Table 8

- 4. Comparison of the nitrogen, phosphorus, and sediment basinwide allocations in the ju risdictions‘ draft Phase I WIPs with the basinwide target nutrient (in millions of pounds per year [mpy]) and sediment allocations (mpy) for 2025

................................ ................................ . 8

- 6DRAFT Chesapeake Bay TMDL

xxi September 24

, 2010

Table 8

- 5. Draft Phase I WIP evaluation ratings by jurisdiction by the three major pollutant loading sourc e sectors

................................ ................................ ................................ .................. 8

- 8

Table 8

- 6. Definitions of the backstop allocation options that EPA considered to replace jurisdictions‘ WIP point source allocations

................................ ................................ ............... 8

- 11

Table 8

- 7. Summary of backstop allocations applied to the seven watershed jurisdictions in developing th e draft Bay TMDL WLAs and LAs

................................ ................................ ..... 8

- 18

Table 8

- 8. Chesapeake Bay watershed nutrient and sediment draft backstop allocations by jurisdiction and by major river basin to achieve the proposed amended Chesapeake Bay WQS

. 8

- 20

Table 8

- 9. Chesapeake Bay watershed nutrient and sediment draft allocations by jurisdiction and by major river basin to achieve the current Chesapeake Bay water quality standards.

............. 8

- 21

Table 9

- 1. Draft Chesapeake Bay TMDL total nitrogen (TN) annual allocations a (pounds per year) by Chesapeak e Bay segment for the proposed amended Chesapeake Bay WQS 9

- 2

Table 9

- 2. Draft Chesapeake Bay TMDL total phosphorus (TP) annual allocations a (pounds per year) by Chesapeake Bay segment for the proposed amended Chesapeake Bay WQS

.............. 9

- 9

Table 9

- 3. Draft Chesap eake Bay TMDL sediment (SED) annual allocations a (thousands of pounds per year) by Chesapeake Bay segment for the proposed amended Chesapeake Bay WQS

................................ ................................ ................................ ................................ .................... 9

- 15

Table 9

- 4. Individual WLAs (Annual) for the 483 significant permitted dischargers to meet

TMDLs to ad dress the proposed amended Chesapeake Bay WQS

................................ ........... 9

- 21

Table 9

- 5. Draft Chesapeake Bay TMDL total nitrogen (TN) annual allocations a (pounds per year) by Chesapeake Bay segment for the current Chesapeake Bay WQS

............................... 9

- 42

Table 9

- 6. Draft Chesapeake Bay TMDL total p hosphorus (TP) annual allocations a (pounds per year delivered to tidal waters) by Chesapeake Bay segment for the current Chesapeake Bay WQS

................................ ................................ ................................ ................................ .................... 9

- 49

Table 9

- 7. Draft Chesapeake Bay TMDL sediment (SED) annual allocations a (thousands of pounds per year) by Chesa peake Bay segment for the current Chesapeake Bay WQS

............ 9

- 55DRAFT Chesapeake Bay TMDL

xxii September 24

, 2010 

## Figures

Figure 1

- 1. CBP‘s organizational structure

. ................................ ................................ ................ 1

- 8 Figure 2

- 1. The Chesapeake Bay watershed with major rivers and cities.

................................ .. 2

- 2 Figure 2

- 2. Hydrogeomorphic regions of the Chesapeake Bay watershed.

................................ . 2

- 4 Figure 2

- 3. Chesapeake Bay watershed land cover.

................................ ................................ .... 2

- 6 Figure 2

- 4. Reported and projected human population growth in the Chesapeake Bay watershed

1950

– 2030.

................................ ................................ ................................ ................................ ... 2

- 7 Figure 2

- 5. The 92 Chesapeake Bay segments.

................................ ................................ ........... 2

- 9 Figure 2

- 6. The 92 Chesapeake Ba y segment watersheds.

................................ ........................ 2

- 14 Figure 3

- 1 . Conceptual illustration of the five Chesapeake Bay tidal water designated use zones.

................................ ................................ ................................ ................................ ...................... 3

- 5 Figure 3

- 2. DO (mg/L) concentrations required by different Chesapeake Bay speci es and biological communities.

................................ ................................ ................................ ............. 3

- 10 Figure 3

- 3. Example cumulative frequency distribution (CFD) curve.

................................ ..... 3

- 20 Figure 3

- 4. Default reference curve used in the attainment assessment of Chesapeake Bay water qualit y criteria for which biologically based reference curves have not yet been derived.

....... 3

- 22 Figure 3

- 5. Example reference and assessment curves showing allowable and non

- allowable

exceedances

................................ ................................ ................................ ................................ 3

- 23 Figure 3

- 6. Di rect model assessment of open water (a), and deep water and deep channel (b)

criteria.

................................ ................................ ................................ ................................ ....... 3

- 25 Figure 4

- 1. Modeled estimated total nitrogen loads delivered to the Chesapeake Bay by jurisdiction in 2009.

................................ ................................ ................................ ..................... 4

- 1 Figure 4

- 2. Model estimated total phosphorus loads delivered to the Chesapeake Bay by jurisdiction in 2009.

................................ ................................ ................................ ..................... 4

- 2 Figure 4

- 3. Model estimated total sediment loads delivered to the Chesapeake Bay by jurisdiction in 2009.

................................ ................................ ................................ ..................... 4

- 3 Figure 4

- 4. Model estimated total nitrogen loads delivered to the Chesapeake Bay by major tributary in 2009.

................................ ................................ ................................ .......................... 4

- 4 Figure 4

- 5. Model estimated total phosphorus loads delivered to the Chesapeake Bay by major

tr ibutary in 2009.

................................ ................................ ................................ .......................... 4

- 5 Figure 4

- 6. Model estimated total sediment loads delivered to the Chesapeake Bay by major tributary in 2009.

................................ ................................ ................................ .......................... 4

- 5 Figure 4

- 7. Significant wastewater treatment facilities in the Chesapeake Bay watershed.

...... 4

- 15 Figure 4

- 8. Nonsignificant m unicipal wastewater treatment facilities in the Chesapeake Bay

watershed.

................................ ................................ ................................ ................................ .. 4

- 16 Figure 4

- 9. Significant industrial wastewater discharge facilities in the Chesapeake Bay

watershed.

................................ ................................ ................................ ................................ .. 4

- 19 Figure 4

- 10. Nonsignificant industrial wastewater discharge facilities i n the Chesapeake Bay

watershed.

................................ ................................ ................................ ................................ .. 4

- 20 Figure 4

- 11. CSO communities in the Chesapeake Bay watershed.

................................ .......... 4

- 23 Figure 4

- 12. Phase I and II MS4s in the Chesapeake Bay watershed.

................................ ....... 4

- 26 Figure 4

- 13. 1985 and 2009 modeled total nitrogen, phosphorus, and sediments loads from agricultural lands across the Chesapeake Bay watershed.

................................ ......................... 4

- 32 Figure 4

- 14. 2007 Chesapeake Bay watershed poultry populations by jurisdiction.

................. 4

- 33 Figure 4

- 15. 2007 Chesapeake Bay watershed livestock populations by jurisdiction.

.............. 4

- 34DRAFT Chesapeake Bay TMDL

xxiii September 24

, 2010

Figure 4

- 16. Principle area of NO X emissions (outlined in blue) that contribute nitrogen deposition to the Chesapeake Bay and its watershed (solid blue fill) (the Bay airshed).

.......... 4

- 37 Figure 4

- 17 Trend of estimated average nitrate and ammonia deposition concentrations i n the

Phase 5 Model domain from 1984 to 2005. .

................................ ................................ ............. 4

- 38 Figure 4

- 18. Estimated 2001 annual total deposition of nitrogen (kg

- N/ha) to North America and adjacent coastal ocean.

................................ ................................ ................................ ............... 4

- 43 Figure 4

- 19. Relative estimates of sources of erosion from land sources (crop, forest, or construction) or bank sources banks and ditch beds).

................................ ................................ 4

- 44 Figure 4

- 20. Sources of total suspended solids in the Chesapeake including the two components of shoreline erosions, fastland and nearshore erosion.

................................ .............................. 4

- 45 Figure 4

- 21. Estimated tidal sedi ment inputs for 1990 from the Chesapeake Bay watershed and from shore erosion. Shoreline sediment inputs (here labeled bank load) are estimated to be about equal to watershed inputs (here labeled as nonpoint source).

................................ .................... 4

- 45 Figure 5

- 1. Tidal monitoring netwo rk stations.

................................ ................................ ........... 5

- 4 Figure 5

- 2. Shallow

- water monitoring illustrating segment completion and latest rotation for Maryland.

................................ ................................ ................................ ................................ ..... 5

- 6 Figure 5

- 3. Example of results from the probability

- based sampling distribution, 1998, to estimate habitat impairment through benthi c community condition assessment.

........................ 5

- 7 Figure 5

- 4. One way of illustrating SAV mapping results.

................................ ......................... 5

- 8 Figure 5

- 5. Watershed monitoring network.

................................ ................................ .............. 5

- 10 Figure 5

- 6. Chesapeake Bay tidal and watershed water quality monitoring networks‘ participants arrayed by thei r role in sample collection, laboratory analysis, or data reporting.

.................... 5

- 14 Figure 5

- 7. Chesapeake Bay TMDL modeling framework.

................................ ...................... 5

- 17 Figure 5

- 8. Atmospheric deposition monitoring stations used in the airshed regression model.

.. 5

- 18 Figure 5

- 9. The CMAQ 12 km grid over the Phase 5 domain.

................................ .................. 5

- 19 Figure 5

- 10. The Land Change Model.

................................ ................................ ...................... 5

- 22 Figure 5

- 11. An example of SPARROW Model output showing delivered yield of total nitrogen in the Chesapeake Bay watershed during 1987.

................................ ................................ ........ 5

- 25 Figure 5

- 12. Scenario Builder conceptual process.

................................ ................................ ... 5

- 26 Figure 5

- 13. Segmentation and reach simulation of the Phase 5.3 Chesapeake Bay Watershed

Model.

................................ ................................ ................................ ................................ ........ 5

- 28 Figure 5

- 14. Phase 5.3 Chesapeake Bay Watershed Model hydrology (upper panel) and water quality (lower panel) monitoring calibration station s overlaid on the Phase 5.3 river segments.

. 5

- 36 Figure 5

- 15. The detailed 57,000 cell grid of the Chesapeake Bay Water Quality and Sediment Transport Model.

................................ ................................ ................................ ........................ 5

- 38 Figure 6

- 1. Graphic comparison of allowable exceedance compared to actual exceedance.

.... 6

- 10

Fi gure 6

- 2. Example of DO criteria nonattainment results from a wide range of nutrient load

reduction model scenarios.

................................ ................................ ................................ ......... 6

- 10 Figure 6

- 3. A graphical representation of how the persistent 1% nonattainment may arise in the criteria assessment of the Chesapeake B ay WQS.

................................ ................................ ..... 6

- 12 Figure 6

- 4. Relative effectiveness for nitrogen for the watershed jurisdictions and major rivers basins, above and below the fall line, in descending order.

................................ ....................... 6

- 22 Figure 6

- 5. Relative effectiveness illustrated geographically by subbasins across the Chesapeake Bay watershed for nitrogen.

................................ ................................ ................................ ....... 6

- 24DRAFT Chesapeake Bay TMDL

xxiv September 24

, 2010

Figure 6

- 6. Relative effectiveness for illustrated geographically by subbasins across the Chesapeake Bay watershed for phosphorus.

................................ ................................ .............. 6

- 25 Figure 6

- 7. Allocation methodology example showing the hockey stick and straight line reductions approaches, respectively, to wastewater (red line) and all other sources (blue line) for nitrogen.

................................ ................................ ................................ ................................ ..... 6

- 29 Figure 6

- 8.Principal areas of nitrogen oxide (blue line) and ammonia (red line) emissions that contribute to nitrogen depositi on to the Chesapeake Bay and its watershed (dark blue fill).

.... 6

- 31 Figure 6

- 9. Chesapeake Bay water quality model simulated DO criteria attainment under various nutrient loading scenarios.

................................ ................................ ................................ ......... 6

- 34 Figure 6

- 10. Example allocation methodology application for pho sphorus.

............................. 6

- 35 Figure 6

- 11. Example allocation methodology application for nitrogen.

................................ .. 6

- 36 Figure 6

- 12. Potomac River chlorophyll a monitoring data compared with the District‘s chlorophyll a water quality criteria.

................................ ................................ ........................... 6

- 41 Figure 6

- 13. James River nonattainment of the chlorophyll a standards at various load scenarios.

................................ ................................ ................................ ................................ .................... 6

- 42 Figure 6

- 14. Tidal James River monitoring data for chlorophyll a at station TF5.5 (located in the upper tidal James River near Hopewell, Virginia) compared to Virginia‘s James River segment

se ason specific chlorophyll a criteria.

................................ ................................ ........................ 6

- 43 Figure 6

- 15. Total nitrogen:total phosphorus exchanges based on anoxic volume days and varying total phosphorus loads.

................................ ................................ ................................ . 6

- 45 Figure 6

- 16. Total nitrogen (TN): total phosphorus (TP) exchanges based on chlorophyll a concentrations and varying total phosphorus loads.

................................ ................................ .. 6

- 46 Figure 6

- 17. Chesapeake Bay SAV/Water Clarity WQS attainment from monitoring data

assessment.

................................ ................................ ................................ ................................ . 6

- 47 Figure 6

- 18. Model simulated sediment loads by scenario compared with the draft range of

sediment all ocations (billions of pounds per year as total suspended sediments).

.................... 6

- 48 Figure 6

- 19. Observed SAV acres in Virginia‘s lower Potomac River segment.

...................... 6

- 50 Figure 7

- 1. Relationship between WIPs and 2

- year milestones.

................................ ................. 7

- 9DRAFT Chesapeake Bay TMDL

xxv September 24

, 2010 

## Foreword

This document describes the technical, legal, and policy underpinnings of the Chesapeake Bay Total Maximum Daily Load (TMDL). While EPA Regions 2 and 3 are establishing this TMDL, it represents the product of decades of monitoring and model development, and years of foc used dialogue and analysis among EPA, our state partners, and numerous stakeholders. This document has benefited from input of hundreds of professionals dedicated to the restoration of the Chesapeake Bay. In accordance with the Clean Water Act and Executive Order 13508 (signed by President Obama on May 12, 2009), the Bay TMDL provides a critical plan to restore and maintain the living resources of the Chesapeake Bay.

A TMDL is required by the Clean Water Act for waters that are on state lists identi fying waters that are not attaining state adopted water quality standards. Most of the waters of the Bay and its tidal tributaries are on the states‘ lists of impaired waters because of excess nitrogen, phosphorus, and sediment. The Chesapeake Bay TMDL ide ntifies the loadings of nitrogen, phosphorus, and sediment that are necessary to achieve the applicable state water quality standards for the Bay and its tidal tributaries for dissolved oxygen, chlorophyll  ̳a‘ (an indication of algae), water clarity, and s ubmerged aquatic vegetation (SAV, or underwater Bay grasses). For this reason, the Chesapeake Bay TMDL has been described as a pollution diet of pollutant loadings necessary to attain water quality and restore the aquatic life resources of the Chesapeake B ay.
The Chesapeake Bay drains streams and rivers from many jurisdictions in the mid

- Atlantic region of the United States including: Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia. Since these waters drain to the Chesapeake Bay and therefore contribute to the pollutant loadings to the Bay, the Chesapeake Bay TMDL will establish total maximum daily loads allowable for these waters and jurisdictions. These loadings are further divided to each of the 92 segments t hat comprise the waters of the Chesapeake Bay and its tidal tributaries. Thus, the Chesapeake Bay TMDL is actually an assemblage of 92 TMDLs, one for each segment, and also one for each pollutant including nitrogen, phosphorus

and sediment.

The focus of th e Chesapeake Bay TMDL is to identify the pollutant loadings needed to restore the Bay, and it thus allocates loading reductions to all source sectors in all parts of the Bay watershed. Because of the Bay

- wide nature of these loading reductions, the water q uality benefits from these reductions will not be limited to the Bay and its tidal tributaries. In fact, all waters from the point the reductions are made to the point that they enter the Bay should benefit from some measure of improved water quality. The controls necessary to reduce nutrients and sediment are also likely to reduce other pollutants.

While the Chesapeake Bay TMDL establishes the pollutant loadings for nitrogen, phosphorus, and sediment needed to restore and maintain a healthy Bay, the TMDL i s an information and planning tool and does not by itself implement the needed controls. Other provisions of the Clean Water Act and state laws, regulations, and funding are needed to achieve these loading levels.

T he Bay TMDL will be implemented using an accountability framework that includes state Watershed Implementation Plans (WIPs) , two

- year milestones, EPA‘s track ing and assess ment
of restoration progress and, as necessary, specific federal actions if the Bay jurisdictions do not

meet their commitment s . The WIPs are the opportunity for each state to set up a system of controls and allocations to attain the respective loading cap for that state basin, which EPA willDRAFT Chesapeake Bay TMDL

xxvi September 24

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consider in making its TMDL allocation decisions. The accountability framework is being

established in part to provide demonstration of the reasonable assurance provisions of the Chesapeake Bay TMDL pursuant to both Section 117(g)(1) of the CWA and Executive Order 13508, but is not part of the Chesapeake Bay TMDL itself. The accountability fr amework is designed to help ensure that these nutrient goals and water quality requirements, as embodied in the Chesapeake Bay TMDL, are met.

An executive summary provides an overview of the TMDL, highlighting its more important aspects. For more specific information, readers should consult the main document which describes each aspect of the Chesapeake Bay TMDL in detail. Finally, for additional background and supportive material, the reader is referred to the numerous appendices and references

contained i n the main document.

____________ _________________________________________ Date Shawn M. Garvin, Regional Administrator EPA Region III

_____________ _________________________________________ Date Judith A. Enck, Regional Adminis trator EPA Region IIDRAFT Chesapeake Bay TMDL

xxvii September 24

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## Acknowledgements

This document was developed through the collaborative efforts of the U.S. Environmental Protection Agency (EPA) and its seven Chesapeake Bay watershed partners

— Delaware, District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia

— principally through the Chesapeake Bay Program‘s (CBP‘s) Water Quality Goal Implementation Team (WQGIT) (formerly the Water Quality Steering Committee), its principal workgroups and the

former Nutrient Subcommittee. The CBP‘s Principals‘ Staff Committee made decisions on behalf of the partnership and provided policy direction to the WQGIT. Advice, direction and independent peer review were provided by the CBP‘s Scientific and Technical Advisory Committee (STAC), the Local Government Advisory Committee (LGAC) and the Citizen‘s Advisory Committee (CAC). Comments and recommendations gathered through the November

– December 2009 public meetings and webinars were instrumental in ensuring that the published allocations provid e the most benefits to local streams and rivers and still achieve the jurisdictions‘ Chesapeake Bay water quality standards.

The document resulted from the collaborative expertise, input, and feedback of many individuals from the multitude of CBP partnerin g agencies and institutions, local governments, nongovernmental organizations, businesses, and many other involved stakeholders. Their individual and collective contributions are hereby acknowledged. Appendix A provides a detailed member listing of the var ious groups and committees who were instrumental in completing the Chesapeake Bay t otal m aximum d aily l oad or TMDL.

Special acknowledgment is made to past and present members the following CBP committees: WQGIT, Principals‘ Staff Committee , Management Board, STAC, LGAC, CAC, Agriculture Workgroup, Forestry Workgroup, Sediment Workgroup, Urban Stormwater Workgroup, Wastewater Treatment Workgroup, Watershed Technical Workgroup, TMDL Workgroup (formerly Reevaluation Technical Workgroup), and the former Nut rient Subcommittee.

Special acknowledgement is also made to the following individuals (in alphabetical order): Katherine Antos, EPA Region 3 CBP Office; Mike Barnes, Chesapeake Research Consortium/CBP Office; Rich Batiuk, EPA Region 3 CBP Office; Benita Be st

- Wong, EPA Office of Water; Carin Bisland, EPA Region 3 CBP Office; Chris Brosch, University of Maryland/CBP Office; Jon Capacasa, EPA Region 3 Water Protection Division; Peter Claggett, U.S. Geological Survey/CBP Office; Jeff Corbin, EPA Region 3 Office of Regional Administrator; Jim Curtin, EPA Headquarters, Office of General Counsel ; Christopher Day, EPA Region 3 Office of Regional Counsel ; Helene Drago, EPA Region 3 Water Protection Division; Mark Dubin, University of Maryland/ CBP Office ; Jim Edward, EPA Region 3 CBP Office ; J. Charles Fox, EPA Headquarters Office of the Administrator; Shawn Garvin, EPA Regional Administrator; Kelly Gable, EPA Region 3 Office Regional Counsel; Aaron Gorka, Chesapeake Research Consortium/CBP Office; Mike Haire, EPA Offi ce of Water; Suzanne Hall, EPA Region 3 Water Protection Division ; Ruth Izraeli, EPA Region 2 Division of Environmental Planning and Protection; Jeni Keisman, University of Maryland/CBP Office; Victoria Kilbert, Chesapeake Research Consortium/CBP Office; B ob Koroncai, EPA Region 3 Water Protection Division; Lewis Linker, EPA Region 3 CBP Office ; Felix Locicero , EPA Region 2 Division of Environmental Planning and Protection ; Travis Loop, EPA Region 3 CBP Office; Larry Merrill, EPA Region 3 Water Protection D ivision; Linda Miller, EPA Region 3; Jenny Molloy, EPA Region 3 CBP Office/Water Protection Division; Sucharith Ravi, University of Maryland/CBPDRAFT Chesapeake Bay TMDL

xxviii September 24

, 2010

Office ; Jennifer Sincock, EPA Region 3 Water Protection Division; Gary Shenk, EPA Region 3

CBP Office ; Kell y Sh enk, EPA Region 3 CBP Office ; Rachel Streusand, Chesapeake Research Consortium/CBP Office; Jeff Sweeney, University of Maryland/CBP Office; Nita Sylvester

, EPA Region 3 CBP Office ; Peter Tango, U.S. Geological Survey/CBP Office; Tom Wall, EPA Headquarters Office of Water; Ping Wang, University of Maryland/CBP Office; Jing Wu, University of Maryland/CBP Office; John Wolf, U.S. Geological Survey/CBP Office; Rob Wood, EPA Region 3 CBP Office; and Ning Zhou, Virginia Polytechnical and State University/EPA Regio n 3 CBP Office.DRAFT Chesapeake Bay TMDL

xxix September 24

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Members of the CBP‘s Water Quality Goal Implementation Team gather in Lancaster, Pennsylvania, in April 2009 to discuss development of the Chesapeake Bay TMDL.DRAFT Chesapeake Bay TMDL

1

- 1 September 24

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## SECTION 1. INTRODUCTION

This document establishes t otal m aximum d aily loads (TMDLs) for n utrients (nitrogen and phosphorus) and s ediment for the Chesapeake Bay and its tidal tributaries and embayments as required by section 303(d) of the Clean Water A ct (CWA) and its implementing regulations at

Title 40 of the Code of Federal Regulations (CFR) section 130.7. This TMDL represents the culmination of decades of collaboration among many partners and stakeholders and is the result of an analysis of water qu ality pollution and its solution on an unprecedented geographic, scientific, and political scale. While all TMDLs are unique, this TMDL is distinguished by the magnitude of the watershed it addresses and the wealth of data developed and analyses

conducted over the course of the past decades that support its conclusions.

In an effort to keep the Bay TMDL document as clear and succinct as possible, discussion of the technical analyses and modeling that support the pollutant allocations are reasonably summary in nature with links provided to the more detailed technical support documentation. Because of the large size of the watershed and the many individual sources, load allocations (LAs) and wasteload allocations (WLAs) that are summarized in Section 9 are pre sented in greater detail in supporting appendices.

This document is organized into 11 sections as follows :

Section 1: CWA and regulatory, statutory, and historical background of the Chesapeake Bay T MDL

Section 2: Description of the Chesapeake Bay watershed , the Bay, and its impaired
segments
Section 3: The jurisdictions‘ Chesapeake Bay water quality standards (WQS)

Section 4: The major sources of nutrients and sediment in the Bay, its watershed and its

airshed

Section 5: The modeling tools used to develop t he WLAs and LA s
Section 6: How the TMDL was developed, including the allocation methodology and

related considerations

Section 7: Discussion of reasonable assurance, Bay TMDL implementation, and the Bay TMDL accountability framework

Section 8: The evaluation of jurisdictions‘ Watershed Implementation Plans (WIP) and decisions on backstop allocations

Section 9: The individual TMDLs for the 92 Bay tidal segments

Section 10: Adaptive management approach to Bay TMDL implementation

Section 11: Documentat ion of public participation, comments, and responsesDRAFT Chesapeake Bay TMDL

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- 2 September 24

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This document also contains three additional sections providing: a list of references (Section 12), a glossary (Section 13), and a list of abbreviations (Section 14).

Additional supporting information th at is not part of this document, or its appendices, can be

found as follows:

Technical documentation for each of the Chesapeake Bay TMDL models

— airshed, land change, Scenario Builder, SPARROW, watershed, Bay water quality/sediment transport, oyster filter feeder and menhaden filter feeder

— are provided via URL in Section 5.

Each of the jurisdictions‘ Phase I Watershed Implementation Plans (WIPs) is provided via URL in Section 7. The WIPs are part of the accountability framework meant to implement the Bay TMD L, but they are not part of the Bay TMDL itself. EPA also is reviewing the WIPs as part of the information to inform its allocation decisions.

Publicly accessible agreements, documents, reports, papers, meeting summaries, and correspondence developed durin g the decades and more recent years leading up to the Chesapeake Bay TMDL, which were instrumental in setting the scientific, policy, and legal foundation on which the Bay TMDL is built, are provided via URL in Appendix B

.



### 1.1. TMDL s and the CWA

Section 303(c) of the 1972 CWA requires states, including the District of Columbia, (collectively

referred to as jurisdictions ) to establish WQS that identify each waterbody‘s designated uses and the criteria needed to support those uses. The CWA establish es a rebuttable presumption that all waters can attain beneficial aquatic life uses, i.e., fishable and recreational uses, i.e., swimmable

.
Section 303(d) of the CWA requires states, including the District of Columbia, (collectively

referred to as jurisdic tions ) to develop lists of impaired waters that fail to meet WQS set by jurisdictions even after implementing technology

- based and other pollution controls. EPA‘s regulations for implementing CWA section 303(d) are codified in the Water Quality Planning

an d Management Regulations at 40 CFR Part 130. The law requires that jurisdictions establish priority rankings and develop TMDLs for waters on the lists of impaired waters (40 CFR 130.7).

A TMDL specifies the maximum amount of a pollutant that a waterbody ca n receive and still meet applicable WQS. A mathematical definition of a TMDL is written as the sum of the individual WLAs for point sources, the LAs for nonpoint sources and natural background, and a margin of safety [CWA section 303(d)(1)(C)]:

TMDL = Σ WLA + Σ LA + MOS

where

WLA = wasteload allocation, or the portion of the TMDL allocated to existing and/or future point sources.

LA = load allocation, or the portion of the TMDL attributed to existing and/or future nonpoint sources and natural backgroun d.

MOS = margin of safety, or the portion of the TMDL that accounts for any lack of knowledge concerning the relationship between effluent limitations and water quality, such as uncertainty about the relationship between pollutant loads andDRAFT Chesapeake Bay TMDL

1

- 3 September 24

, 2010 receiving wat er quality, which can be provided implicitly by applying conservative analytical assumptions or explicitly by reserving a portion of loading capacity.

The process of calculating and documenting a TMDL involves a number of tasks and

— especially for a large, complex, multijurisdictional waterbody with multiple impairments

— can require substantial effort and resources

. Major tasks involved in the TMDL develop ment process include the following:

Characterizing the impaired waterbody and its watershed

Identifying and inventorying the relevant pollutant source sectors

Applying the appropriate WQS

Calculating the loading capacity using appropriate modeling analyses to link pollutant loads to water quality

Identifying the required source allocations

The Bay TMDL report presents the results of the numerous analyses and model simulations and documents the informational elements described above. Because the Chesapeake B ay watershed is so large, and the analysis required for developing the Bay TMDL so extensive, the Chesapeake Bay TMDL and its supporting documentation consists of this report and additional supporting materials in the numerous appendices referenced through out the report. The Bay TMDL is also supported by an extensive list of significant documents (Appendix B).



### 1.2 History of the Chesapeake Bay TMDL

The Chesapeake Bay watershed has been inhabited for thousands of years, but the population

started to increase significantly with the arrival of European settlers in the 1600s

. Settlers began clearing forests for timber and to make room for expanding agricultural activities, increasing soil erosion and nutrient delivery to the Bay and its tributaries (Curtin et al . 2001; Rountree et al. 2007)

. As early as 1900, the oyster population began to decline. Throughout the 20 th c entury, urban development and agricultural activities increased throughout the watershed. In the late 1970s, Maryland Senator Charles Mathias spon sored a c ongressionally funded, 5

- year study to analyze the rapid loss of aquatic life that was affecting the Bay. That study identified e xcess nutrient pollution as the main source of the Bay ‘ s degradation (USEPA 1982, 1983a, 1983b, 1983c, 1983d)

.



### 1.2.1 R egulatory and Management Initiatives

In response to the Bay‘s decline, various regulatory and management initiatives have been undertaken aimed at Bay restoration, ranging from cooperative agreements among surrounding jurisdictions to regulatory and policy programs. Through the years, the agreements and alliances have become more formalized and inclusive to address the multitude of factors contributing to the deterioration in Chesapeake Bay water quality. The following paragraphs outline the major policy, l egislative, and programmatic events that have led to the development of the Bay TMDL, including the management agreements and regulatory requirements that form the underpinning

of the TMDL.DRAFT Chesapeake Bay TMDL

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1983 Chesapeake Bay Agreement

I n 1983 the governors of Maryland, V irginia, and Pennsylvania ; the mayor of the District of

Columbia ; the chairman of the Chesapeake Bay Commission; and EPA‘s Administrator signed

the first Chesapeake Bay Agreement. In th at agreement, the signatories acknowledged the decline in living resour ces of the Chesapeake Bay and agreed to establish the Chesapeake

Executive Council (CEC) to ―assess and oversee the implementation of coordinated plans to improve and protect the water quality and living resources of the Chesapeake Bay estuarine systems‖ ( Chesapeake Bay Partnership 1983 ).

1987 Chesapeake Bay Agreement

Faced w ith the need to take a more comprehensive and coordinated approach to restoring water quality and living resources of the Chesapeake Bay, the signatories to the 1983 a greement
entered i nto the 1987 Chesapeake Bay Agreement (CEC 1987 ). The 1987 Chesapeake Bay

A greement set priority goals and commitments , of which a key goal was to ―reduce and control point and nonpoint sources of pollution to attain the water quality condition necessary t o support the living resources of the B ay

. ‖ T o achieve th at goal

, signator ies to the 1987 Bay Agreement

committed to reduce the controllable nitrogen and phosphorus loads delivered to the mainstem of the Chesapeake Bay by 40 percent by 2000 and to develop a B ay

- wide implementation strate gy to achieve those reductions (CEC 1987 ).

CWA Section 117 and the Chesapeake Bay Program (CBP)
In the 1987 amendments to the CWA, Congress

— in section 117

— authorized the formation and funding of the CBP withi n EPA Region 3. Congress directed the CBP to collect and disseminate information related to the environmental quality of the Bay, to ―coordinate state and federal efforts to improve Bay water quality, to evaluate sediment impacts on the Bay, and to determi ne the impact of natural and human

- induced environmental changes on the living resources of the Bay.‖

1

1991 Reevaluation

A 1991 reevaluation of progress made toward the 1987 Bay Agreement‘s 40 percent nutrient reduction goal led to a detailed quantification of the original narrative goal. Each major river basin by jurisdiction received a ―tributary nutrient load allocation‖ as a ―40% controllable load reduction‖ for both nitrogen and phosphorus as the p rincipal outcome of the reevaluation (Secretary Robert Perciasepe 1992). The 1991 reevaluation also introduced several concept s still applicable in the Bay TMDL: t ributary s trategies (WIPs), limit of technology (E3 scenario), recognition of air deposition ( air allocation to tidal surface waters ) , and geographic

- based allocations (relative effectiveness

- based allocation methodology)

. 1992 Amendments to the Chesapeake Bay Agreement

The 1991 reevaluation led to several amendments to the 1987 Chesapeake Bay Agr eement in 1992, including an increased focus on the importance of tributarie s in the Bay‘s restoration. The parties to the 1987 Chesapeake Bay Agreement were to begin by 1993 to d evelop and implement tributary

- specific strategies to meet mainstem nutrient reduction goals

, to improve water quality

, and to restore living resources to the mainstem and tributaries ( CEC 1992). T he amendments

1 Clean Water Act section 117 (33 United States Code [U.S.C.] 1267).DRAFT Chesapeake Bay TMDL

1

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also established the distribution of submerged aquatic vegetation (SAV) as an initial measure of progress toward the water quality and living resource goals of the 1987 Agreement.

1997 Reevaluation
In 1997 the CBP conducted a year

- long evaluation to assess what progress had been made toward the goal set in the 1987 A greement of a 40 percent reduction in nitrogen and phosphorus

delivered to the B ay by 2000 ( CEC 1997 ). The 1997 r eevaluation found that between 1985 and 1996 phosphorus loads delivered to the B ay declined by 6 million pounds annually

, and nitrogen loads delivered to the Bay decli ned by 29 million pounds annually. By 1996 phosphorus loads

from wastewater dischargers had been reduced by 51 percent in the participating jurisdictions as a result of implement ing effluent standards, upgrad ing wastewater treatment plants

, and ban ning pho sphate laundry detergents . Wastewater nitrogen loads were reduced by 15 percent by implement ing biological nutrient removal at some major municipal wastewater treatment facilities and industrial wastewater treatment facility upgrades

. Implementation of nutrient

reduction best management practices ( BMPs ) reduced nonpoint source loadings of nitrogen and phosphorus to the B ay by 7 and 9 percent, respectively . T here was no clear trend in B ay dissolved oxygen (DO) levels , however. Although p rogress was made, the 1997 r eevaluation

r eport stated, ―we must accelerate our efforts to close the gap on the year 2000 goal, maintain those reduced loading levels into the future and if necessary adjust the nutrient goals to help us achieve the water qua lity improvements needed to sustain living resources in the Bay‖ ( CBP

1997 )

. 1999 Integration of Cooperative and Statutory Programs
In September 1999, senior water quality program managers representing the jurisdictions and

EPA outlined the Process for Int egrating the Cooperative and Statutory Programs of the Chesapeake Bay and its Tributaries

— Continuing the Watershed Partnership to Restore the Chesapeake Bay (CBP 1999). That consensus document laid the groundwork for the water quality goals and commitments within the Chesapeake 2000 Agreement. A decade in advance, it set the partnership on a course that culminated in the Bay TMDL.

Chesapeake 2000 Agreement

In June 2000 the governors of Maryland, Virginia

, and Pennsylvania ; the mayor of the District of

Colum bia ; the Administrator of EPA ; and the chairman of the Chesapeake Bay Commission signed the Chesapeake 2000 A greement ( CEC 2000 ). To meet the goal of ―achieving and maintaining the water quality necessary to support the aquatic living resources of the Bay and its tributaries and to protect human health,‖ the signatories committed to specific actions , including:

Continue to achieve and maintain the 40 percent nutrient reduction goal agreed to

in 1987.DRAFT Chesapeake Bay TMDL

1

- 3 September 24 , 2010

By 2010, correct nutrient

- and sediment

- related problems in the Chesapeake Bay and its tidal tributaries sufficiently to remove the Bay and the tidal portions of its tributaries from the list of impaired waters under the Clean Water Act. In order to

achieve this:

1. By 2001, define the water quality conditions nec essary to protect aquatic living resources and then assign load reductions for nitrogen and pho sphorus to each major tributary;

2. Using a process parallel to that established for nutrients, determine the sediment load reductions necessary to achieve the wate r quality conditions that protect aquatic living resources, and assign load reductions for sediment to each major tributary by 2001;

3. By 2002, complete a public process to develop and begin implementation of revised Tributary Strategies to achieve and main t ain the assigned loading goals;

4. By 2003, the jurisdictions with tidal waters will use their best efforts to adopt

new or revised [WQS] consistent with the defined water quality conditions

. Once adopted by the jurisdictions, the Environmental Protection Age ncy will work expeditiously to review the new or revised standards, which will then be used as the basis for removing the Bay and its tidal rivers f rom the list of impaired waters; and

5. By 2003, work with the Susquehanna River Basin Commission and others to adopt and begin implementing strategies that prevent the loss of the sediment retention capabilities of the lower Susquehanna River dams

.

2000 Six

- Jurisdiction Memorandum of Understanding

In the f all of 2000, EPA, Delaware, the District of Columbia, Maryland, New York, Pennsylvania, and Virginia signed a Memorandum of Understanding (MOU) (Chesapeake Bay Watershed Partners 2000), with West Virginia joining as a signatory in June 2002, agreeing to the following:

W ork cooperatively to achieve the nutrien t and sediment reduction targets necessary to achieve the goals of a clean Chesapeake Bay by 2010 , thereby allowing the Chesapeake Bay and its tidal tributaries to be removed from the list of impaired waters

. Provide for an inclusive, open and comprehensiv e public participation process.

Collaborate on the development and use of innovative measures such as effluent trading, cooperative implementation mechanisms, and expanded interstate agreements to achieve the necessary reductions.

The signatories also agreed to report annually on progress toward achieving the goals of the
agreement

. 2003 Nutrient and Sediment Cap Load Allocations
In 2003 EPA and its watershed partners established nutrient and sediment cap loads on the basis

of the Bay water quality mode l projections of attainment of the then EPA

- proposed DO wa ter quality criteria under long

- term average hydrologic conditions (Secretary Tayloe Murphy 2003).DRAFT Chesapeake Bay TMDL

1

- 4 September 24 , 2010

Reaching those cap loads was expected to eliminate the summer anoxic conditions in the deep

waters of the Bay and the excessive algal blooms throughout the Bay and tidal tributaries (USEPA 2003b).

EPA and its watershed jurisdiction partners allocated the nutrient cap loads among the major river basins. Those jurisdictions with the highest impact on B ay water quality were assigned the highest nutrient reductions, while jurisdictions without tidal waters received less stringent reductions because they would not realize a direct benefit from the improved water quality conditions in the Bay (USEPA 2003b). Se diment allocations were based on the phosphorus

equivalent allocations to each major river basin by jurisdiction (USEPA 2003b).

Although not original signatories of the Chesapeake 2000 Agreement , New York, Delaware, and West Virginia signed on as partners in implementing the cap loads; thus, all seven B ay jurisdictions were assigned allocations (Chesapeake Bay Watershed Partners 2000; USEPA 2003b). The final total basinwide cap loads agreed to by the jurisdictions were 175 million pounds for nitrogen and 12 .8 million pounds of phosphorus delivered to the tidal waters of the Bay (USEPA 2003b). The basinwide upland sediment cap load was 4.15 million tons (USEPA 2003b).

2004

– 2006 Tributary Strategies
To implement the cap loads , the seven watershed jurisdictions developed what became known as the Chesapeake Bay Tributary Strategies ( Table 1

- 1 ) (Secretary Tayloe Murphy 2003). The tributary strategies outlined river basin

- spec ific implementation activities to reduce nitrogen, phosphorus, and sediment from point and nonpoint sources sufficient to remove the Chesapeake Bay and its tidal tributaries and embayments from the Bay jurisdictions‘ respective impaired waters lists. Many of the policies and procedures used in developing the Chesapeake Bay TMDL originated with the development of the 2003 nutrient and sediment cap loads and subsequent development of tributary strateg ies

.

Table 1

- 1

. URLs for accessing the seven Chesapeake Bay watershed jurisdictions’ tributary strategies

Jurisdiction Tributary strategy

Delaware http://www.chesapeakebay.net/watershedimplementationplantools.aspx?menuitem=52044

District of
Columbia http://www.chesapeakebay.net/watershedimplementationplan tools.aspx?menuitem=52044

Maryland http://www.dnr.state.md.us/bay/tribstrat/implementation_plan.html

New York http://www.dec.ny.gov/docs/water_pdf/cbaystratfinal.pdf Pennsylvania http://www.chesapeakebay.net/watershedimplementationplantools.aspx?menuitem=52044

V irginia http://www.chesapeakebay.net/watershedimplementationplantools.aspx?menuitem=52044 West Virginia http://www.wvca.us/bay/files/bay_documents/8_9657_WV_Potomac_Tributary_Strategy_FIN

AL_from_web.pdf

2004

– 2005 Jurisdiction Adoption of Chesapeake Bay Water Quality Standards

In continued efforts to coordinate activities to address nutrient and sediment

- based pollution in the Bay, the tidal jurisdictions of Maryland, Virginia, Delaware, and the District of Columbia adopted into their respe ctive WQS regulations the EPA

- published Chesapeake Bay water quality

criteria for DO

, water clarity, SAV, and chlorophyll a , along with criteria attainment assessmentDRAFT Chesapeake Bay TMDL

1

- 5 September 24 , 2010

procedures and refi ned tidal water designated uses (for details, see Section 3) (USEPA 20 03a, 2003c). EPA approved those WQS modifications pursuant to CWA section 303(c).

2007 Reevaluation Secretary Tayloe Murphy‘s 2003 memorandum summarized the comprehensive set of agreements made by Bay watershed partners with regard to cap loads for nitroge n, phosphorus

, and sediment ; new B ay

- wide and local SAV restoration goals; and a commitment to reevaluate the allocations in 2007. The initiation of that reevaluation at a workshop in September 2005 laid the institutional groundwork for the collaborative w ork on the Bay TMDL (Chesapeake Bay Reevaluation Steering Committee 2005).

EPA and the seven jurisdictions reevaluate d the nutrient and sediment cap loads in 2007, in
response to the four Bay jurisdictions revising their WQS regulations for the Chesapeake Bay and its tidal tributaries (Secretary Tayloe Murphy 2003). The 2007 reevaluation found that sufficient progress had not been made toward improving water quality in the Chesapeake Bay to

a level that the mainstem Chesapeake Bay and its tidal tributaries were no longer impaired by nutrients and sediment (Chesapeake Bay Reevaluation Steering Committee 2005).



### 1.2.2 Partnership Commitment to Develop the Chesapeake Bay TMDL

Throughout the Bay TMDL development process, EPA has worked in close and open partnersh ip with all seven watershed jurisdictions, sharing decision making with the jurisdictions via the CBP structure described in more detail in Section 1.3. While EPA is developing the Bay TMDL, the seven watershed jurisdictions have been essential partners in the initiative, providing critical input and participating in deliberations and key decisions affecting the development process. The

seven Bay watershed jurisdictions and EPA have been building the foundation for the Chesapeake Bay TMDL since signing the Chesapeake 2000 Agreement

, which laid out the steps necessary to put in place an appropriate framework for a future Bay TMDL, including consistent jurisdictional Chesapeake Bay WQS (CEC 2000).

From September 2005 to the present, the seven watershed jurisdi ctions have been actively involved in decision making related to developing the Bay TMDL through participation in the

CBP‘s Principals‘ Staff Committee ( PSC), Water Quality Goal Implementation Team (WQGIT),

and other decision

- making committees and technica l workgroups (see Section 1.3.1 ). The full records of the meetings and conference calls of th o se groups are access ible via the Internet

— see Appendix C

.
At the October 1, 2007, meeting of the PSC, the seven watershed jurisdictions and EPA reached

consensus 2 that EPA would establish the Bay TMDL on behalf of the jurisdictions with a target restoration date of 2025 (CBP PSC 2007). Table 1

- 2 summarizes that and the other B ay TMDL

relevant consensus agreements reached by the partners during that meeting.

2 Consensus within the Principals‘ Staff Committee means that all parties present have either agreed on this as a course of action and/or that no party objected to it.DRAFT Chesapeake Bay TMDL

1

- 6 September 24 , 2010

Table 1

- 2 . Summary of Chesapeake Bay TMDL relevant actions agreed to by the CBP ’s Principals’ Staff Committee during its Octo ber 1, 2007

, meeting

The Bay watershed TMDLs will be developed jointly between the six Bay watershed states, the

District

, and EPA and then established by EPA. The Water Quality Steering Committee (WQSC) will draft nutrient and sediment cap load allocations by tributary basin by jurisdiction, and the PSC will formally adopt these allocations. The watershed states and the District would have responsibility for further assigning loads

— WLA s and LA s

— to source s consistent with EPA regulations and guidance. These state/District suballocations (WLA/LA) would become part of the overall Bay watershed TMDLs report. The final publication would contain all the required documentation supporting the EPA Bay

watershed TM DLs in a single, integrated publication with extensive appendices. EPA will provide the technical resources/analyses required to support development of the Bay watershed TMDLs through the CBP Office staff and EPA

- funded contractor support. The Bay watershe d TMDLs must be completed and established by EPA no later than May 1, 2011.

The CBP partners will engage stakeholders and the public in a more extensive structured dialogue about the tributary strategy implementation challenges before us.

The CBP partners will focus on getting the programs in place by 2010 that we believe are required to achieve our water quality goals.

The CBP partnership‘s public announcement of initiation of work on the Bay watershed TMDLs will occur following the states‘ submi ssion and EPA approval of the 2008 303(d) lists in the spring 2008

time frame. Eight principles will guide the reevaluation efforts by the WQSC and its workgroups (see Attachment A for more detailed version):

o Shared urgency to restore the Bay;

o Clear commun ication and common message;

o Focus and accelerate implementation (do no harm);

o Engage the public about the implementation challenge;

o Legal obligations will be met;

o Improving and applying the latest science;

o Flexibility of the sub

- allocations within the majo r basins; and

o Keep healthy waters healthy.

The WQSC will proceed forward with the responsibility for carrying out the necessary preparation work following these eight guiding principles. The state/EPA Reevaluation Technical Workgroup (RTWG) will be reconvened and operate under

the direction of the WQSC

. The RTWG was charged with responsibility for resolving the existing technical issues in light of the desire to accelerate implementation at all scales. The WQSC will convene a parallel Implem entation Workgroup and charge this group with the responsibility for ensuring that the reevaluation and TMDL development process results in acceleration of ongoing tributary strategy implementation.

Source: CBP PSC 2007



### 1.2.3 President’s Chesapeake Bay E xecutive Order

On May 12, 2009, President Barack Obama issued the Chesapeake Bay Protection and Restoration Executive Order 13508, which call s for the federal government to lead a renewed effort to restore and protect the Chesapeake Bay and its watershed. Critical among its directives

were

Establish a Federal Leadership Committee to oversee the development and coordination of reporting, data management and other activities by agencies involved in Bay restoration

.DRAFT Chesapeake Bay TMDL

1

- 7 September 24 , 2010

Require involved agencies to prepare and sub mit reports with recommendations on a wide range of Bay issues ( EPA

- HQ

- OW

- 2009

- 0761; FRL

- 8978

- 8 )

. Require the Federal Leadership Committee to develop a Strategy for Protecting and Restoring the Chesapeake Bay by May 2010 (see http://executiveorder.chesapeakebay.net/ ).

Require the Federal Leadership Committee to publish an annual Chesapeake Bay Action Plan describing how Federal funding proposed in the President‘s Budget will be used to protect and restore the Chesapeake Bay during the upcoming fiscal year.

Require f ederal agencies to consult extensively with Bay jurisdictions in preparing their
reports

.

Pursuant to the Executive Order, on May 12, 2010, the Federal Leadership Committee

— led by

the EPA Administrator and secretaries from the Departments of Agriculture, Commerce, Defense, Homeland Security, Interior, Transportation and others

— issued its coordinated strategy for restoring the Chesapeake Bay (FLCCB 2010). That strategy sets measurable goals for improving environmental conditions in the Bay for the following:

Clean water

Habitat

Fish and wildlife

Land and public access

Other supporting strategies address citizen stewardship, climate change, science, and implementation and accountability.

A key element of the approach for meeting water quality goals is the development of this TMDL for the Chesapeake Bay (FLCCB 2010).

Parallel to the issuance of the Executive Order, the jurisdictions and the federal government committed to implement all necess ary measures for restoring water quality in the Bay by 2025 and to meet specific milestones every 2 years ( FRL

- 8955

- 4; Clean Water Act Section 303(d): Preliminary Notice of Total Maximum Daily Load (TMDL) Development for the Chesapeake Bay ). To that end, E PA is developing a n accountability framework to guide the overall restoration effort and to link it to implementation of the Chesapeake Bay TMDL. The accountability framework , which is discussed in more detail in Section 8

, includes four elements:

Waters he d Implementation Plans (WIPs)

T wo

- year milestones to demonstrate restoration progress

EPA‘s commitment to track and assess progress

Federal actions if the watershed jurisdictions fail to develop sufficient WIPs, effectively implement their WIPs

, or fulfill their 2

- year milestones



### 1.3 Bay TMDL Process, Partner Coordination and Responsibilities

EPA Region 3 is the lead federal office responsible for develop ing the Chesapeake Bay TMDL

, with the Water Protection Division (WPD) having direct responsibility for publication of the Bay TMDL. In developing this TMDL, WPD has coordinated efforts with the CBP Office , the AirDRAFT Chesapeake Bay TMDL

1

- 8 September 24 , 2010

Protection Division, and the Office of Regional Counsel (all within Region 3), E PA Region 2

, and EPA Headquarters. Throughout the Bay TMDL develo pment process, EPA has worked in close and open partnership with all seven watershed jurisdictions, numerous federal agency partners, and a diverse array of other partners and stakeholders through the CBP partnership.

This section describes the different e lements of the CBP organizational structure and provides additional description of the roles and responsibilities of the various entities and stakeholders involved in developing the Chesapeake Bay TMDL.



### 1.3.1 CBP Partnership and Organizational Structure

Th e CBP is a unique regional partnership within EPA Region 3 that include s Maryland, Pennsylvania, Virginia

, the District of Columbia

, the Chesapeake Bay Commission, EPA

, federal agencies, and participating advisory groups . The headwater states of Delaware, New York, and West Virginia participate as full partners on issues related to water quality. Each of the CBP partners agrees to use its own resources to implement projects and activities that advance Bay

restoration.

The partnership defines its collective actions through formal, voluntary agreements and provides general policy direction through consensus documents, typically called directives. The CBP works through a series of Goal Implementation Teams with oversight provided by the CBP‘s Management Board. Extensive documentation of the CBP structure and governance is provided

in Chesapeake Bay Program Governance

— Managing the Partnership for a Restored and Protected Watershed and Bay ( CBP 2009)

. Figure 1

- 1 shows the CB P organizational chart.

Source: CBP 2009

Figure 1

- 1 . CBP’s organizational structure

.DRAFT Chesapeake Bay TMDL

1

- 9 September 24 , 2010

Chesapeake Executive Council (CEC)
The top executive of each of the s ignatories of the Chesapeake 2000 Agreement (state governors, District of Columbia mayor, EPA Administrator, and Chesapeake Bay Commission Chair), form the CEC, which meets annually to set basinwide policies and the future directions for CBP. Delaware, New York, and West Virginia participate in CEC meetings and have full input status on all water quality

- related matters. PSC members serve as advisors to their respective CEC members. The CEC has played a pivotal role in develop ing the Bay TMDL by signing the Chesapeake 2000 Agreement and subsequent directives and by setting the partnership on a well

defined, 10

- year path directly supporting development of the Bay TMDL ( CEC 2000, 2003, 2005).

Federal Leadership Committee
To bring the full weight of the federal government to address the Chesapeake‘s challenges, President Obama issued Executive Order 13508 on Chesapeake Bay Protection and Restoration and established the Federal Leadership Committee, which is chaired by the Administrator of the

U.S. Environmental Protection Agency and includes senior representatives from the departments of Agriculture, Commerce, Defense, Homeland Security, Interior, and Transportation

.
Principals’ Staff Committee (PSC)
The PSC provided policy and programmatic direction to the Manag ement Board and the WQGIT on the development and adoption of the Chesapeake Bay nutrient and sediment targets and allocations for the Bay TMDL ( Figure 1

- 1 ). The PSC is composed of cabinet

- level representatives from each of the seven watershed jurisdictions, EPA Region 3‘s Regional Administrator, senior federal agency executives, the Chesapeake Bay Commission executive

director and the director of the CBP Office. The Regional Administrator of EPA Region 3 currently chairs the PSC. The Citizens, Local Governments

, and the Scientific and Technical advisory committees all advise the PSC.

Management Board
PSC members provide policy and program direction to the Management Board which, in turn, provide d strategic planning, priority setting, and operational guidance and direction to the WQGIT during the development of the Bay TMDL ( Figure 1

- 1 ). The Management Board is composed of senior policy representatives from the seven watershed jurisdictions, the Chesapeake Bay Commission, the nine core federal agency partners, 3 and the chairs of the Citizens, Local Governments, and t he Scientific and Technical advisory committees. The Management Board directs and coordinates the efforts of the six Goal Implementation Teams

and A ction T eam s . The director of the CBP Office chairs the Management Board, and the CBP Office provides for the staff to support the work of all the Goal Implementation Teams and workgroups. Staffing for the three advisory committees is supported by EPA through cooperative agreements with nonprofit organizations.

Water Quality Goal Implementation Team The WQGIT‘s p urpose is to support efforts to reduce and cap the nutrient and sediment loads entering the Bay and to ensure that such reductions are maintained over time . It is composed of

3 T he Nat ur a l Resources Conservation Service, U.S. Forest Service, National Oceanic and Atmospheric Administration, U.S. Geological Survey , National Park Service, U.S. Fish and Wildlife Service, U.S. Army Corp s of Engineers , U.S. Department of Defense, and EPA.DRAFT Chesapeake Bay TMDL

1

- 10 September 24 , 2010

the members of the former Water Quality Steering Committee and the Nutrient Subco mmittee. The WQGIT provid ed advice and guidance to EPA related to the targets and allocations before they were brought to the PSC. The WQGIT consist s of senior water program managers from

each of the seven Bay watershed jurisdictions , EPA H eadquarters and Regions 2 and 3 , the Chesapeake Bay Commission, the Susquehanna River Basin Commission

, and the Potomac

River Basin Commission . T he WQGIT provided technical direction to the Water shed Technical

, Agriculture, Forestry, Wastewater Treatment, Sediment, and Urban Stormwater workgroups.

Watershed Technical Workgroup
The Watershed Technical Workgroup was c reated to provide a forum for communication among the jurisdictions and other CBP participants on technical issues related to tributary strategy development, tracking and reporting

. Members of the Water shed Technical Workgroup include

technical staff and mid

- level managers from the seven watershed jurisdictions , EPA, and point source and environmental stakeholder groups . For the Chesapeake Bay TMD L, the workgroup provided review and oversight in regards to application of the Bay Watershed Model.

Pollutant Source Workgroups
The Agricultural Workgroup coordinate d and evaluate d agricultural nutrient and sediment reduction measures throughout the juris dictions and resolved issues related to tracking, reporting, and crediting conservation practices

.
The Forestry Workgroup provided information on the effectiveness of different riparian forest buffer restoration and other forest management practices.

The W astewater Treatment Workgroup provide d a formal means of communication among f ederal agencies, state agencies/jurisdictions, and wastewater treatment plants.

The Sediment Workgroup provide d technical and policy

- related assistance to the CBP partners in

set ting the sediment allocations

.

The Urban Stormwater Workgroup provided input related to all aspects of stormwate r nutrient and sediment loads and management practices.

Science, Technical Analysis, and Reporting Team

— Criteria Assessment Protocols

Workgroup
The Criteria Assessment Protocols Workgroup had the lead responsibility for ensuring coordinated assessment of all Chesapeake Bay and tidal tributary/embayment waters related to the Bay jurisdictions‘ listing and delisting under CWA section 303(d). The wor kgroup also had the lead in developing, reviewing, and recommending to the WQGIT amendments to the original 2003 Chesapeake Bay water quality criteria.

Science, Technical Analysis, and Reporting Team

— Modeling Workgroup
The Modeling Workgroup, formerly the Modeling Subcommittee and now under the Science, Technical Analysis, and Reporting (STAR) team, oversaw the development, calibration, verification, and management application of the suite of computer

- based Bay models that supported the development of the B ay TMDL. The models allowed managers to estimate the pollutant load reductions needed to achieve WQS and to assess the potential of different management scenarios to achieve the needed pollutant load reductions.DRAFT Chesapeake Bay TMDL

1

- 11 September 24 , 2010

Scientific and Technical Advisory Committee

The Scientific and Technical Advisory Committee ( STAC ) is composed of scientists from academic institutions from all seven watershed jurisdiction and federal science agencies, representing a diverse range of disciplines. STAC provide s scientific and techni cal guidance and peer review to the CBP partnership on measures to restore and protect the Chesapeake Bay

. STAC activities related to the Bay TMDL included providing for independent scientific peer reviews of all the Bay models (watershed, land change, estuarine water quality, estuarine sediment transport), Bay criteria assessment procedures, land use data, and reviewing and commenting on the draft Bay TMDL.

Local Governments Advisory Committee

The Local Governments Advisory Committee ( LGAC ) is a body of officials appointed by the

g overnors of Maryland, Pennsylvania, Virginia, and the m ayor of the District of Columbia to improve the role local governments can play in Bay restoration efforts and develop strategies to broaden local government participation in the CBP

. The LGAC was directly involved in develop ing the Bay TMDL in the following ways : ensured the direct involvement of local

elected officials in the decision

- making processes, helped establish the local WIP pilots in 2010 (before development of th e Phase II WIPs in 2011), and helped inform the thousands of local governments across the watershed about the Bay TMDL.

Citizen’s Advisory Committee

The Citizens Advisory Committee ( CAC ) provided advice to the C EC , the PSC, the Management Board

, and all the Goal Implementation Teams as needed in implementing the Chesapeake Bay Agreement. The CAC directly assisted the Bay TMDL development process by providing detailed recommendations on how to engage the nongovernmental components of the larger Bay watersh ed community and placing a strong focus on ensuring full accountability during the development and throughout the long

- term implementation of the Bay TMDL.

Appendix A provides the membership lists of all the above described committees, teams, and workgroup s at the time of publication of the Bay TMDL, fully acknowledging their individual

and collective contributions.



### 1.4 Legal Framework for the Chesapeake Bay TMDL

1.4.1. What is a TMDL?

As discussed more fully in Section 1.1, a TMDL specifies the maximum amo unt of a pollutant that a waterbody can receive and still meet applicable WQS. Allocations to point sources are called WLAs, while allocations to nonpoint sources are called LAs. A TMDL is the sum of the individual WLAs (for point sources), LAs (for nonpoi nt sources and natural background) (40 CFR 130.2), and a margin of safety [CWA section 303(d)(1)(C)]. Section 303(d) requires that

TMDL s be established for impaired waterbodies ― at a level necessary to implement the applicable [WQS] .‖ 4

TMDLs are ―primaril y informational tools‖ that ―serve as a link in an implementation chain that includes federally regulated point source controls, state or local plans for point and nonpoint

4 33 U.S.C. 1313(d)(1)(C).DRAFT Chesapeake Bay TMDL

1

- 12 September 24 , 2010

source pollutant reduction, and assessment of the impact of such measures on water quality, all to the end of attaining water quality goals for the nation‘s waters.‖ 5 Recognizing a TMDL‘s role as a vital link in the implementation chain, f ederal regulations require that effluent limits in NPDES permits be ― consistent with the assumption s and requirements of any available WLA ‖ in an approved TMDL. 6

In addition, before EPA establishes or approves a TMDL that allocates pollutant loads to both point and nonpoint sources, it determines whether there is reasonable assurance that the nonpoint source LAs will , in fact, be achieved and WQS will be attained ( USEPA 1991 a). If the

reductions embodied in LAs are not fully achieved, the collective reductions from point and nonpoint sources will not result in attainment of the WQS

.

The Bay TMDL will be implemented using an accountability framework that includes WIPs

, 2

- year milestones, EPA‘s track ing and assess ment of restoration progress and, as necessary, specific federal actions if the Bay jurisdictions do not meet their commitmen ts

. The accountability framework is being established

, in part, to demonstrate that the TMDL is supported by reasonable assurance

. The accountability framework is also being established
pursuant to CWA s ection 117(g)(1) . Section 117(g) of the CWA directs t he EPA Administrator to ―ensure that management plans are developed and implementation is begun...to achieve and maintain...the nutrient goals of the Chesapeake Bay Agreement for the quantity of nitrogen and phosphorus entering the Chesapeake Bay and its w atershed, [and] the water quality requirements necessary to restore living resources in the Chesapeake Bay ecosystem.‖ 7 In addition, Executive

Order 13508 directs EPA and other federal agencies to build a new accountability framework that guides local, st ate, and federal water quality restoration efforts . The accountability framework is designed to help ensure that the Bay‘s nutrient goals, as embodied in the Chesapeake Bay TMDL, are met. While the accountability framework informs the TMDL section 303(d) d oes not require that EPA ―approve‖ the framework per se , or the jurisdictions‘ WIPs that constitute part of that framework.



### 1.4.2. Why is EPA establishing this TMDL?

In 1998 data showed the mainstem and tidal waters of the Chesapeake Bay to be impaired for aquatic life resources. EPA determined that the mainstem and tidal waters of the Chesapeake Bay must be placed on Virginia‘s section 303(d) list. EPA therefore added the mainstem of the Chesapeake Bay to Virginia‘s final section 303(d) list. As described in Section 2, each river, tributary, and other waterbody that is part of the Chesapeake Bay TMDL is included on a jurisdiction‘s section 303(d) list.

EPA is establishing the Chesapeake Bay TMDL pursuant to a number of existing authorities, including the CW A and its implementing regulations

, judicial c onsent d ecrees requiring EPA to address certain impaired Chesapeake Bay and tidal tributary waters, a settlement agreement resolving litigation brought by the Chesapeake Bay Foundation, the cu rrent Chesapeake Bay Agreement, and Executive Order 13508. In establishing the Bay TMDL, EPA has acted pursuant

5 Pronsolino v. Nastri, 291 F.3d 1123, 1129 (9 th Cir. 2002).

6 40 CFR 122.44(d)(1)(vii)(B).

7 Clean Water Act section 117(g)(1)(A)

- (B), 33 U.S.C. 1267(g)(1)(A)

- (B).DRAFT Chesapeake Bay TMDL

1

- 13 September 24 , 2010

to the consensus direction of the Chesapeake Executive Council ‘s PSC and in partnership with

each of the seven Chesapeake Bay watershed jurisdic tions.

The CWA provides EPA with ample authority to establish the Chesapeake Bay TMDL. CWA section 117(g)(1) provides that ―[t]he Administrator, in coordination with other members of the [CEC], shall ensure that management plans are developed and implemen tation is begun by signatories to the Chesapeake Bay Agreement to achieve and maintain [among other things] the nutrient goals of the Chesapeake Bay Agreement for the quantity of nitrogen and phosphorus entering the Chesapeake Bay and its watershed [and] t he water quality requirements necessary to restore living resources in the Chesapeake Bay ecosystem.‖ Because it establishes the Bay and tidal tributaries‘ nutrient and sediment loading and allocation targets, the Chesapeake Bay

TMDL is such a management p lan

. In addition, the Bay TMDL‘s loading and allocation targets both inform and are informed by, a larger set of federal and state management plans being developed for the Bay, including the jurisdiction WIPs and the May 2010 Bay strategy.

CWA section 303 (d) requires jurisdictions to establish and submit TMDLs to EPA for review. Under certain circumstances, EPA also has the authority to establish TMDLs. The circumstances of this TMDL do not necessarily identify the outer bounds of EPA‘s authority. However, where impaired waters have been identified on jurisdictions‘ section 303(d) lists for many years, where the states in question have decided not to establish their own TMDLs for those waters, where EPA is establishing a TMDL for those waters at the directi on of, and in cooperation with, the jurisdictions in question, and where those waters are part of an interrelated and interstate water system like the Chesapeake Bay that is impaired by pollutant loadings from sources in seven different jurisdictions, CWA section 303(d) authorizes EPA authority to establish that TMDL 8

.

On May 12, 2009, President Barack Obama signed Executive Order 13508

— Chesapeake Bay

Protection and Restoration

. The Executive Order‘s overarching goal is ―to protect and restore the health, heritage, natural resources, and social and economic value of the Nation‘s largest estuarine ecosystem and the natural sustainability of its watershed.‖ The Executive Order says the federal government ―should lead this effort‖ and acknowledges that progres s in restoring the Bay ―will depend on the support of state and local governments.‖ To that end, the Executive Order directs the lead federal agencies, including EPA, to work in close collaboration with their state partners. To protect and restore the Ches apeake Bay and its tidal tributaries, the President directed EPA to ―make full use of its authorities under the [CWA].‖ In establishing the Bay TMDL, EPA is doing no more

— or less

— than making full use of its CWA authorities to lead a

collaborative and effec tive federal and state effort to meet the Bay‘s nutrient and sediment goals.

A number of consent decrees , MOUs, and settlement agreements provide additional support for
EPA‘s decision to establish the Chesapeake Bay TMDL addressing certain waters identifie d as impaired on the Maryland, Virginia

, and District of Columbia‘s 1998 section 303(d) list s and on

the Delaware 1996 section 303(d) list . EPA is establishing t h e Chesapeake Bay TMDL

consistent with those consent decrees , MOUs, and settlement agreements, described below.

8 Dioxin/Organochlorine Center v. Clarke , 57 F.3d 1517 ( 9 th Cir. 1995); Scott v. City of Hammond , 741 F.2d 992 (7 th Cir. 1984); American Canoe Ass ’ n. v EPA , 54 F.Supp.2d 621 (E.D.Va. 1999).DRAFT Chesapeake Bay TMDL

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- 14 September 24 , 2010

Virginia

– EPA Consent Decree

The American Canoe Association, Inc.

, and the American Littoral Society filed a complaint against EPA for failing to comply with the CWA, including s ection 303(d)

, regarding the TMDL program in the Commonwealth of Virginia. A consent decree signed in 1999 resolved the litigation. 9 The consent decree include s a 1 2

- year schedule for develop ing TMDLs for impaired
segments identified on Virginia‘s 1998 s ection 303(d) list

. The c onsent d ecree requires EPA to

establish TMDLs for th o se waters, by May 1, 2011

, if Virginia fails to do so according to the established schedule. Virginia has requested that EPA establish TMDLs for the nutrient

- and

sediment

- impaired tidal portions of the Chesapeake Bay and its tributaries in a ccordance with the Virginia c onsent d ecree schedule (CBP PSC 2007)

. Table 1

- 1 provides a list of the Virginia consent decree waters that will be addressed by the Chesa peake Bay TMDLs for nutrients and

sediment

.

9 American Canoe Association v

. EPA , 98cv979 (June 11, 1999).DRAFT Chesapeake Bay TMDL

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- 15 September 24 , 2010

Table 1

- 3

. Virginia consent decree (CD) waters impaired for dissolved oxygen (DO) and/or nutrients that will be addressed by the Chesapeake Bay TMDL

Waterbody Name CD Segment ID Chesapeake Bay

Segment ID CD Impairment Bailey Bay, Bailey Creek

– Tidal VAP

- G03E JMSTF1 DO

Broad Creek VAT

- G15E ELIPH, WBEMH,SBEMH,

EBEMH DO Chesapeake Bay Mainstem Narrative a CB5MH, CB6PH, CB7PH Nutrients Chesapeake Bay Mainstem VACB

- R01E CB5MH, CB6PH, CB7PH DO

Elizabeth River

– Tidal Narrative b ELIPH, WBEMH,SBEMH,

EBEMH Nutrients Hungars Creek VAT

- C14R CB7PH DO

James River

– Tidal Narrative c JMSTF2, JMSTF1, JMSOH, JMSMH, JMSPH Nutrients King Creek VAT

- F27E YRKPH DO
Mattaponi River

– Tidal Narrative d MPNTF, MPNOH Nutrients Messongo Creek VAT

- C10E POCMH DO

North Branch Onancock Creek VAT

- C11E CB7PH DO
Pagan River VAT

- G11E JMSMH DO
Pamunkey River

– Tidal Narrative e PMKTF, PMKOH Nutrients

Queen Creek VAT

- F26E YRKMH DO
Rappahannock River Narrative f RPPMH Nutrients
Rappahannock River VAP

- E25E RPPMH Nutrients
Rappahannock River VAP

- E25E RPPMH DO
Rappahannock River VAP

- E26E RPPMH Nutrients
Rappahannock River VAP

- E26E RPPMH DO

Thalia Creek VAT

- C08E LYNPH DO

Williams Creek VAN

- A30E POTMH DO

York River Narrative g YRKMH, YRKPH Nutrients

York River VAT

- F27E YRKPH DO

Source: American Canoe Association v

. EPA , 98cv979 (June 11, 1999).

Notes: a = Chesapeake Bay Mainstem (VACB

- R01E) impaired for nutrients
b = Elizabeth River (VAT

- G15E) impaired for DO, nutrients c = James River ( VAP

- G01E, VAP

- G03E, VAP

- G02E, VAP

- G04E, VAP

- G11E, and VAP

- G15E) impaired for nutrients d = Mattaponi River (VAP

- F24E and VAP

- F25E) impaired for nutrients e = Pamunkey River (VAP

- F13E an d VAP

- F14E) impaired for DO, nutrients f = Rappahannock River (VAP

- E24E) impaired for DO g = York River (VAT

- F26E) impaired for nutrients

District of Columbia

– EPA Consent Decree
In 1998 Kingman Park Civic Association and others filed a similar suit against EPA

. 10 The

lawsuit was settled through the entry of a consent decree requiring EPA to, among other things, establish TMDLs for the District of Columbia‘s portions of the tidal Potomac and tidal Anacostia

r ivers if not establis hed by the District of Columbia by a certain date

.

10 Kingman Park Civic Association v EPA , 98cv00758 (June 13, 2000).DRAFT Chesapeake Bay TMDL

1

- 16 September 24 , 2010

The impairment of the District of Columbia‘s portion of the upper tidal Potomac River by low pH is directly related to the Chesapeake Bay water quality impairments because the low pH is a

result of excess nutrients causing algal blooms in the tidal river . Establishing a tidal Potomac

River pH TMDL is directly linked to establishing the Chesapeake Bay TMDL because of their common impairing pollutants (nutrients) and the hydrologic connection between the Dist rict‘s portion of the tidal Potomac River and the Chesapeake Bay. EPA and the Kingman Park plaintiffs jointly sought, and received on February 12, 2008, a formal extension of the D istrict of

Columbia TMDL Consent Decree so that EPA could complete the Potom ac River pH TMDL on the same sche dule as the Chesapeake Bay TMDL. The District of Columbia requested that EPA establish the pH TMDL for the District‘s portion of the tidal Potomac River ( CBP PSC 2007 ).

Table 1

- 4 provides a list of the District‘s consent decree waters that will be addressed by the Chesapeake Bay TMDLs for nutrients and sediment

.
In addition, Anacostia Riverkeeper and Friends of the Earth filed suit agains t EPA challenging more than 300 TMDLs for the District of Columbia, including the Anacostia River TMDLs, because the TMDLs did not contain daily loads. On May 25, 2010, the District Court for the

District of Columbia ordered the vacatur of the District of Columbia‘s TMDL for pH for the Washington Ship Channel, with a stay of vacatur until May 31, 2011. With the Bay TMDL, the Washington Ship Channel pH impairment will be addressed and will supersede the pH TMDL for the Ship Channel approved by EPA on Decembe r 15, 2004.

Table 1

- 4

. District of Columbia consent decree (CD) waters impaired for pH that will be addressed by the Chesapeake Bay TMDL
Waterbody Name CD Segment ID Chesapeake Bay Segment ID CD Impairment Washington Ship Channel DCPWC04E_00 POTTF_DC pH

Middle Potomac River DCPMS00E POTTF_DC pH

Source: Kingman Park Civic Association v EPA , 98cv00758 (June 13, 2000).

Delaware

– EPA Consent Decree
In 1996 the American Littoral Society and the Sierra Club filed a suit against EPA to ensure that

TMDLs were developed for waters on Delaware ‘s 1996 section 303(d) list , one of which is a tidal Bay segment (Upper Nanticoke). The parties entered into a consent decree resolving the

lawsuit. 11 The consent decree re quired EPA to establish TMDLs if Delaware fail ed to do so

within the 10

- year TMDL development schedule

. Although Delaware establish ed TMDLs for the one listed tidal Bay segment (DE DNREC 1998), the TMDLs were established to meet prior WQS and are insuffici ent to attain Chesapeake Bay WQS

.
Maryland

– EPA MOU
In 1998 Maryland and EPA Region 3 entered into an MOU that, among other things, established

a 10

- year schedule for addressing waters on Maryland ‘s 1998 section 303(d) list, with completion by 2008 (MDE 1998 ). Because of funding constraints, the complexity of some TMDLs, and limited staff resources, Maryland determined that it would not be able to address all 1998 listed waters by 2008 . Further, t he Chesapeake 2000 A greement established a goal of meeting water quality goals in the Chesapeake Bay by 2010 (CEC 2000 ). Many of the waters on

11 American Littoral Society, et al. v EPA, et al. , 96cv591 (D.Del. 1997).DRAFT Chesapeake Bay TMDL

1

- 17 September 24 , 2010

Maryland ‘s 1998 section 303(d) list were open waters of the Bay or tidal tributaries to the Bay

. Maryland determined that developing TMDLs for th o se tidal waters before th e deadline established by the MOU , as would be required under the schedule established in 1998

, ―would undermine the spirit of the agreement‖ because of a lack of integration between the CBP and Maryland efforts ( MDE 2004). Therefore, Maryland decided to p ostpone development of TMDLs for Maryland‘s listed Chesapeake Bay and tidal tributary waters until the two programs

could coordinate efforts.

In September 2004, Maryland and EPA Region 3 entered into a revised MOU that extended the

schedule for TMDL develo pment to 13 years (by 2011) ( MDE 2004)

. Although neither Maryland nor EPA is under a consent decree for establish ing TMDLs for Maryland waters , the state has requested that EPA develop the TMDLs for the Maryland portion of the Chesapeake Bay and tidal trib utaries impaired by excess nutrients and sediment as recognized in the MOU between Maryland and EPA (CBP PSC 2007).

Chesapeake Bay Foundation Settlement Agreement
In January 2009, the Chesapeake Bay Foundation and others filed suit against EPA in U.S.

Dist rict Court for the District of Columbia (1:09

- cv

- 00005

- CKK) alleging, among other things, that EPA had failed to carry out nondiscretionary duties under CWA s ection 117(g) designed to restore and preserve the Chesapeake Bay

. In May 2010, EPA signed a settl ement agreement with the plaintiffs promising to take a number of actions to restore and preserve the Bay

. In particular, EPA promised that by December 31, 2010

, it would establish a TMDL for those segments of the Chesapeake Bay impaired by nitrogen, phosp horus

, and sediment

. EPA is establishing this TMDL, in part, to meet that commitment.DRAFT Chesapeake Bay TMDL

2

- 1 September 24 , 2010



## SECTION 2. WATERSHED AND IMPAIRMENT

DESCRIPTION

This section provides a general description of the watershed and the impairments addressed in the Chesapeake Bay TMDL. Section 2.1 provides a description of the basic history, geography, land uses, and recent development patterns and trends. Section 2.2 presents the scope of the TMDL including the parameters of concern, the specific impairment listings addressed, and the TMDL segmenta tion.



### 2.1 General Watershed Setting

The Chesapeake Bay watershed includes parts of six states

— Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia

— and the entire District of Columbia (collectively, the jurisdictions). The Chesapeake Bay proper is approximately 200 miles long, stretching from Havre de Grace, Maryland, to Norfolk, Virginia. It varies in width from about 3.4 miles near Aberdeen, Maryland, to 35 miles near the mouth of the Potomac River. T he easternmost boundary of the Chesap eake Bay with the Atlantic Ocean is represented by a line between Cape Charles and Cape Henry

. Including its tidal tributaries, the Chesapeake Bay encompasses approximately 11,684 miles of shoreline.

About half of the Bay‘s water volume consists of saltwat er from the Atlantic Ocean. The other

half is freshwater that drains into the Bay from its 64,000

- square

- mile watershed ( Figure 2

- 1 )

. Ninety percent of th e freshwater is delivered from five major rivers: the Susquehanna (which is responsible for about 50 percent), Potomac, James, Rappahannock

, and York r ivers. In all, the

watershed contains more than 100,000 streams and rivers that eventually flow into the Bay.DRAFT Chesapeake Bay TMDL

2

- 2 September 24 , 2010 Figure 2

- 1 . The Chesapeake Bay watershed with major rivers and cities.

Runoff from the Bay‘s enormous watershed flows into an estuary with a surface area of 4,500 square miles resulting in a land

- to

- water ratio of 14 to 1. Th at large ratio is one of the key factors in explaining why the drainage area has such a significant influence on water quality in the Bay

.
Although the Chesapeake Bay is entirely within the Atlantic Coastal Plain, its watershed includes parts of the Piedmont and Appalachian provinces. The waters that flow into the Bay have different chemical identities, depending on the geology from wh ich they originate ( Figu re 2

- 2 )

.DRAFT Chesapeake Bay TMDL

2

- 3 September 24 , 2010

The Atlantic Coastal Plain is a flat, lowland area with a maximum elevation of about 300 feet. It is supported by a bed of crystalline rock, covered with southeasterly d ipping wedge

- shaped layers of relatively unconsolidated sand, clay

, and gravel

. Water passing through th e loosely compacted mixture dissolves many of the minerals. The most soluble elements are iron, calcium

, and magnesium. The coastal plain extends from the edge of the continental shelf, to the east, to a

fall line that ranges from 15 to 90 miles west of the Chesapeake Bay. Th e fall line , which is the location where free flowing streams enter tidal waters, forms the boundary between the Piedmont Plateau and the coastal plain. Waterfalls and rapids clearly mark this line, which is cl ose to
Interstate 95. At the fall line , the elevation rises to 1,100 feet.

The Piedmont Plateau extends from the fall line in the east to the Appalachian Mountains in the

west. Th e area is divided into two geologically distinct regions by Parrs Ridge, whic h traverses Carroll, Howard

, and Montgomery counties in Maryland and adjacent counties in Pennsylvania. Several types of dense

, crystalline rock

— including slates, schists, marble

, and granite

— compose the eastern side of the Piedmont Plateau . Th at variety results in a very diverse topography. Rocks

of the Piedmont tend to be impermeable, and water from the eastern side is low in calcium and magnesium salts. The western side of the Piedmont consists of sandstones, shales

, and siltstones, layered ove r by limestone. Th e limestone bedrock contributes calcium and magnesium to its water, making it hard . Waters from the western side of Parrs Ridge flow into the Potomac River, one of the Chesapeake Bay‘s largest tributaries.DRAFT Chesapeake Bay TMDL

2

- 4 September 24 , 2010

Source: USGS WRIR 00

- 424

Figu re 2

- 2

. Hydrogeomorphic regions of the Chesapeake Bay watershed.DRAFT Chesapeake Bay TMDL

2

- 5 September 24 , 2010

The Appalachian Province covers the western and northern part of the watershed and is rich in coal and natural gas deposits. Sandstone, siltsto ne, shale

, and limestone form the bedrock. Water

from th at province flows to the Chesapeake Bay mainly via the Susquehanna River.

Earliest evidence of human inhabitants in the Bay watershed is of hunter

- gatherers as long as 10,000 years ago, while Native A mericans began cultivating crops and settling in villages throughout the area around 1,000 years ago. European settlement less than 500 hundred years ago began a period of transformation of forests into farmland, while today many of those lands are undergo ing retransformations into urban and suburban lands.

Over the past hundreds of years

, forest clearing and urban development have resulted in the following land use breakdown in the watershed: 69.4 percent wooded/open, 22.1 percent agriculture, 7.1 percent developed, and 1.4 percent open water and extractive ( Figure 2

- 3 )

. From 1950 through 2008, the Bay watershed‘s population doubled, increasing from 8.3 million

to 16.8 million. The 8

- year period from 2000 to 2008 witnessed population growth of approximately 7 percent from 15.7 million. Today, nearly 17 million people live in the watershed. According to census data, the watershed‘s population is growing by about 157,000 per year. Projections through 2030 are for the population to reach approximately 20 millio n ( Figure 2

- 4 ).DRAFT Chesapeake Bay TMDL

2

- 6 September 24 , 2010

Source: USGS CBPO

Figure 2

- 3

. Chesapeake Bay watershed land cover.DRAFT Chesapeake Bay TMDL

2

- 7 September 24 , 2010

Source: CBP Office Bay Barometer 2009

Figure 2

- 4

. Reported and projected human population growth in the Chesapeake Bay watershed 1950

– 2030.



### 2.2 Chesapeake Bay TMDL Scope

T he Chesapeake Bay TMDL is the largest, most complex TMDL in the country

, covering a 64,000

- square

- mile area in the seven jurisdictions

. EPA is establishing a federal TMDL for the

tidal segments of the Chesapeake Bay and its tidal tributaries and embayments that are impaired for aq uatic life uses due to excessive loads of nutrients (nitrogen and phosphorus) and sediment

and listed on the four tidal Bay jurisdictions‘ respective CWA 2008 section 303(d) list s of impaired waters

. The Bay TMDL also allocate s loadings of nitrogen , phosph orus, and sediment

to sources contributing those pollutants in all seven jurisdictions in the Bay watershed

— De laware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia.

As described more fully in Section 2.2.1 below, t he Chesapeake Bay TMDL addresses only the restoration of aquatic life uses for the Bay and its tidal tributaries that are impaired from excess nitrogen, phosphorus, and sediment. If Bay segments are impaired for other pollutants, EPA expects that the juris dictions will develop separate TMDLs to address those pollutants.

Thousands of previously approved TMDLs have been established to protect local waters across the Chesapeake Bay watershed. While many addressed other pollutants

, some addressed nitrogen, phos phorus, and /or sediment. For watersheds and waterbodies that have both local

TMDLs and Chesapeake Bay TMDL s for nitrogen, phosphorus, and sediment, the more stringent of the TMDLs will apply. In some cases, the reductions required to meet local conditions shown in existing TMDLs may be more stringent than those needed to meet Bay requirements, and vice

versa. 0 5 10 15 20 25

1950 1960 1970 1980 1990 2000 2010 2020 2030



## Population Projections (Millions)DRAFT Chesapeake Bay TMDL

2

- 8 September 24 , 2010



### 2.2.1 Pollutants of Concern

The pollutants of concern for this TMDL are nutrients

— nitrogen and phosphorus

— and

sediment. Excessive nutrients in the Che sapeake Bay and its tidal tributaries promote a number of undesirable water quality conditions such as excessive algal growth, low DO , and reduced water clarity (Smith et al. 1992; Kemp et al. 200 5 ). The effect of nutrient loads on water quality and living resources can vary considerably by season and region.

Sediment suspended in the water column reduce s the amount of light available to support healthy

and extensive SAV or underwater Bay grass communities (Dennison et al. 1993; Kemp et al. 2004). The relat ive contribution of suspended sediment and algae that cause s poor light conditions varies with location in the Bay tidal waters (Gallegos 2001).

Sediment also can contain other pollutants

. For example

, Escherichia coli often cling s to
sediment

. By reducing sediment

, reductions in phosphorus deliveries to the Bay ( and possibly other pollutants such as E. coli ) will also occur. However, EPA is not providing allocations for E.

coli or other additional pollutants in this TMDL

.
If Bay segments are impaired for o ther pollutants, EPA expects that the jurisdictions will develop separate TMDLs to address those pollutants. Because of the actions taken to achieve the Chesapeake Bay TMDL, direct benefits to local water quality conditions in surface waters throughout the Chesapeake Bay watershed will also occur.



### 2.2.2 Chesapeake Bay Program Segmentation Scheme

For 27 years, the CBP partners have used various versions of a basic segmentation scheme to organize the collection, analysis, and presentation of environmental dat a relating to the Chesapeake Bay . The Chesapeake Bay Program Segmentation Scheme: Revisions, D ecisions

and R ationales provides documentation of the spatial segmentation scheme of the Chesapeake Bay and its tidal tributaries and the later revisions and chan ges over almost three decades (USEPA 1983 b , 2004b, 2005, 2008 a ).

Segmentation is the compartmentalization of the estuary into subunits on the basis of selection criteria (USEPA 2008 a ). The 92

- segment scheme used in the Chesapeake Bay was derived from

the 2 00 4 published 78

- segment scheme with additional jurisdictional boundary lines imposed to create 89 segments (USEPA 2004b, 2008a) . The scheme includes only the split segments 12
agreed on for the tidal James and Potomac r ivers for a total of 92 segments ( Figure 2

- 5 ) ( Table

2

- 1 ) (USEPA 2008 a ). T he 92 individual wat ersheds that drain directly into one of the 92 Chesapeake Bay segments are referred to in this document as Bay segment watershed s ( Figure

2

- 6 ).

Table 2

- 1 lists the eight major river basins draining to the Chesapeake Bay and their associated Bay segments with information related to each Bay segment‘s 2008 section 303(d) list status and whether the Bay segment is addressed by a consent decree or MOU. The 303(d) list categories

are as follows:

12 A split segment refers to when an established tidal Bay segment was fully bisected for purposes of applying different water quality criteria specific to two different po rtions of the same segment

— in the case of the James River, or different assessments of attainment of the same applicable criteria separately from the main river
segment

— in the case of the Potomac River.DRAFT Chesapeake Bay TMDL

2

- 9 September 24 , 2010

Source: USEPA 2008 a

Figure 2

- 5

. The 92 Chesapeake Bay segments.DRAFT Chesapeake Bay TMDL

2

- 10 September 24 , 2010

Category 1

— attaining all WQS

Category 2

— attaining some WQS

Category 3

— insufficient information to determine if WQS are attained

Category 4

— impaired or threatened waters that do not need or have already completed a

TMDL

o 4a

— TMDL has been completed

o 4b

— Other pollution control requirements are reasonably expected to result in the attainment of the WQS in the near future

o 4c

— Impairment is not caused by a pollutant

Category 5

— impaired or threatened water that requires a TMDL

Most Bay segments are listed as category 5 (impaired for most/all de signated uses); exceptions

are noted in Table 2

- 1

.

Table 2

- 1 . The Chesapeake Bay 303(d) tidal segment s with consent decr ee (CD)/memorandum of understanding (MOU) and 303(d) listing status by major river basin and jurisdiction
Major river
basin Juris

diction Chesapeake Bay

303(d) segment Segment ID CD/MOU 2008 list status a

Eastern
Shore MD Big Annemessex River BIGMH

-- 5

MD Bohemia River BOHOH MD MOU 4a for TN and TP

DE C&D Canal, DE C&DOH_DE

-- 5

MD C&D Canal, MD C&DOH_MD MD MOU 5

MD Eastern Bay EASMH MD MOU 5

VA Eastern Lower

Chesapeake Bay CB7PH VA CD 5

MD Elk River ELKOH MD MOU 5

MD Fishing Bay FSBMH MD MOU 4a for TN and TP

MD Honga River HNGMH MD MOU 5

MD Little Choptank River LCHMH MD MOU 5

MD Lower Chester River CHSMH MD MOU 5

MD Lower Choptank River CHOMH 2 MD MOU 5

MD Lower Nanticoke River NANMH

-- 5

MD Lower Pocomoke

River, MD POCMH_MD MD MOU 5

VA Lower Pocomoke

River, VA POCMH_VA VA CD 5

MD Manokin River MANMH MD MOU 4a for TN and TP

MD Middle Chester River CHSOH MD MOU 4a for TN and TP

MD Middle Choptank River CHOOH MD MOU 5

MD Middle Nanticoke River NANOH MD MOU 5

MD Middle Pocomoke

River, MD POCOH_MD MD MOU 5

VA Middle Pocomoke

River, VA POCOH_VA

-- 5

MD Mouth of Choptank

River CHOMH 1 MD MOU 5

MD Northeast River NORTF MD MOU 4a for TN and TPDRAFT Chesapeake Bay TMDL

2

- 11 September 24 , 2010

Major river
basin Juris

diction Chesapeake Bay

303(d) segment Segment ID CD/MOU 2008 list status a

MD Sassafras River SASOH MD MOU 4a for TP

MD Tangier Sound, MD TANMH_MD MD MOU 5

VA Tangier Sound, VA TANMH_VA

-- 5

MD Upper Chester River CHSTF MD MOU 4a for TN and TP

MD Upper Choptank River CHOTF MD MOU 5

DE Upper Nanticoke, DE NANTF_DE DE CD
finished 5

MD Upper Nanticoke, MD NANTF_MD MD MOU 5

MD Upper Pocomoke River POCTF MD MOU 5

MD Wicomico River WICMH MD MOU 5

James VA Appomattox River APPTF

-- 5

VA Chickahominy River CHKOH

-- 5

VA Eastern Branch

Elizabeth River EBEMH VA CD 5

VA Lafayette River LAFMH

-- 5

VA Lower James River JMSMH VA CD 5

VA Lynnhaven River LYNPH VA CD 5

VA Middle James River JMSOH VA CD 5

VA Mouth of Chesapeake

Bay CB8PH

-- 5

VA Mouth of James River JMSPH VA CD 5

VA Mouth to mid

- Elizabeth

River ELIPH VA CD 5

VA Southern Branch

Elizabeth River SBEMH VA CD 5

VA Upper James River

-

Lower JMSTF1 VA CD 5

VA Upper James River

-

Upper JMSTF2 VA CD 5

VA Western Branch

Elizabeth River WBEMH VA CD 5

Patuxent MD Lower Patuxent River PAXMH MD MOU 5

MD Middle Patuxent River PAXOH MD MOU 5

MD Upper Patuxent River PAXTF MD MOU 5

MD Western Branch

Patuxent River WBRTF MD MOU BOD TMDL completed
for DO impairments ; 4a
for BOD

Potomac DC Anacostia River, DC ANATF_DC DC CD 3 for DO; 4a for BOD

, TN, TP and TSS

MD Anacostia River, MD ANATF_MD MD MOU 4a for BOD, TN, TP and
TSS

VA Lower Central

Chesapeake Bay, VA b CB5MH_VA b VA CD 5

MD Lower Potomac River,

MD POTMH_MD MD MOU 5

VA Lower Potomac River,

VA POTMH_VA VA CD 5

MD Mattawoman Creek MATTF MD MOU 5DRAFT Chesapeake Bay TMDL

2

- 12 September 24 , 2010

Major river
basin Juris

diction Chesapeake Bay

303(d) segment Segment ID CD/MOU 2008 list status a

MD Middle Potomac River,

MD

- Mainstem POTOH1_MD MD MOU 5

MD Middle Potomac River,

MD

- Nangemoy Creek POTOH2_MD MD MOU 5

MD Middle Potomac River,

MD

- Port Tobacco
River POTOH2_MD MD MOU 4a for TN and TP

VA Middle Potomac River,

VA POTOH_VA

-- 3 for DO in Migratory Spawning and Nursery (MSN); 2 for SAV and DO in open water

MD Piscataway Creek PISTF MD MOU 5

DC Upper Potomac River,

DC POTTF_DC DC CD 3 for DO, 5 for pH

MD Upper Potomac River,

MD POTTF_MD MD MOU 5

VA Upper Potomac River,

VA POTTF_VA

-- 3 for DO in Migratory Spawning and Nursery; 2 for SAV and DO in open

water Rappa

hannock VA Corrotoman River CRRMH

-- 5

VA Lower Rappahannock

River RPPMH VA CD 5

VA Middle Rappahannock

River RPPOH

-- 3 for DO in Migratory Spawning and Nursery; 2 for SAV and DO in open

water

VA Upper Rappahannock

River RPPTF

-- 5

VA Western Lower

Chesapeake Bay b CB6PH b VA CD 5

Susque

hanna MD Northern Chesapeake Bay b CB1TF b MD MOU 5

Western
Shore MD Back River BACOH MD MOU 4a for TN and TP

MD Bush River BSHOH MD MOU 5

MD Gunpowder River GUNOH MD MOU 5

MD Lower Central

Chesapeake Bay, MD b CB5MH_MD b MD MOU 5

MD Magothy River MAGMH MD MOU 5

MD Middle Central

Chesapeake Bay b CB4MH b MD MOU 5

MD Middle River MIDOH MD MOU 5

MD Patapsco River PATMH MD MOU 5

MD Rhode River RHDMH MD MOU 5

MD Severn River SEVMH MD MOU 5

MD South River SOUMH MD MOU 5

MD Upper Central

Chesapeake Bay b CB3MH b MD MOU 5

MD Upper Chesapeake CB2OH b MD MOU 5DRAFT Chesapeake Bay TMDL

2

- 13 September 24 , 2010

Major river
basin Juris

diction Chesapeake Bay

303(d) segment Segment ID CD/MOU 2008 list status a Bay b

MD West River WSTMH MD MOU 5

York VA Lower Mattaponi River MPNOH VA CD 5

VA Lower Pamunkey River PMKOH VA CD 5

VA Lower York River YRKPH VA CD 5

VA Middle York River YRKMH VA CD 5

VA Mobjack Bay MOBPH

-- 5

VA Piankatank River PIAMH

-- 5

VA Upper Mattaponi River MPNTF VA CD 5

VA Upper Pamunkey River PMKTF VA CD 5

Sources: American Canoe Association v. EPA; American Littoral Society, et al. v. EPA, et al.; DC DOE 2008; DE DNREC 2008; Kingman Park Civic Association, et al. vs. EPA; MDE 1998, 2004, 2008; USEPA 2008 a ; VA DEQ

2008

a. BOD = biological oxygen demand; DO = dissolved oxygen; TN = total nitrogen; TP = total phosphorus; TSS = total suspended solid s b. More than one river basin flows into this tidal segmentDRAFT Chesapeake Bay TMDL

2

- 14 September 24 , 2010

Source: USEPA 2008 a

Figure 2

- 6

. The 92 Chesapeake Bay segment watersheds.DRAFT Chesapeake Bay TMDL

2

- 15 September 24 , 2010



### 2.2.3 Jurisdictions’ 2008 303(d) Listings
The Chesapeake Bay TMDL is based on the most recent EPA

- approved tidal Bay jurisdictions‘ section 303(d) lists, which are the 2008 303(d) listings. 13 Those section 303(d) lists document 89 of the 92 Chesapeake Bay segments as impaired on either Category 4a (impaired, TMDL has been developed) or Category 5 (impaired, needs TMDL) because of various factors, including low DO levels, insufficient SAV, excess chlorophyll a , biological/nutrient indicators, total nitrogen, total phosphorus, total suspended solids (TSS), biological oxygen demand (BOD), and pH (caused by excessive nutrients fueling algal blooms) (DC DOE 2008 ; DE DNREC 2008; MDE 2008; VADEQ 2008).

Three Chesapeake Bay segments are not listed in Category 4a or 5 on Virginia‘s 2008 integrated

report:

Upper Potomac River (POTTF_VA)

Middle Potomac River (POTOH_VA)

Middle Rappahannock River (RPPOH)

Those three segm ents are listed as either Category 2 (some uses met, other uses have insufficient information to determine impairment) or Category 3 (insufficient information to determine if impaired) (VA DEQ 2008). Because their listing status raises a reasonable questio n as to whether those three segments are impaired, and because those segments are tidally interconnected with other impaired Bay segments, it is appropriate that they also be addressed by the Chesapeake Bay TMDL.

The first segment, Virginia‘s Upper Potomac River (POTTF_VA), encompasses a series of small tidal embayments that are tidally interconnected with Maryland‘s Upper Potomac River (POTTF_MD) segment and the District of Columbia‘s Upper Potomac River (POTTF_DC)
segment (USEPA 2008a), both of which are listed as Category 5 of Maryland‘s and the District of Columbia‘s respective 2008 integrated reports (DCDOE 2008; MDE 2008). Loads originating in the watershed that drains directly Virginia‘s Upper Potomac River segment influence the water quality in the two adjacent Maryland and District of Columbia impaired tidal segments and

other down

- tide segments.

The second segment, Virgi nia‘s Middle Potomac River (POTOH_VA), also encompasses a series of small tidal embayments that are tidally interconnected with Maryland‘s Middle Potomac River (POTOH_MD) segment (USEPA 2008a), which is listed as Category 5 on Maryland‘s 2008 integrated re port (MDE 2008). Loads originating in the watershed that drains directly to Virginia‘s Middle Potomac River segment influence the water quality in the adjacent Maryland impaired tidal segment and other down

- tide segments.

The third segment, Virginia‘s Midd le Rappahannock River (RPPOH), is tidally interconnected with both the Lower Rappahannock River (RPPMH) and the Upper Rappahannock River (RPPTF) segments (USEPA 2008a), both of which are listed as Category 5 on Virginia‘s 2008

13 At the time EPA applied the Bay models for developm ent of the allocations, the 2008 section 303(d) lists were the most recent lists. Although EPA subsequently received final 2010 section 303(d) lists for approval from all tidal jurisdictions except Virginia (Virginia draft 2010 section 303(d) list released for public review on August 23, 2010)

, EPA used the 2008 lists in establishing the Bay TMDL to have a consistent basis for the TMDL.DRAFT Chesapeake Bay TMDL

2

- 16 September 24 , 2010

integrated report (VADEQ 2008 ). Loads originating in the watershed that drains directly to Virginia‘s Middle Rappahannock River segment influence the water quality in the adjacent Virginia impaired tidal segments and other down

- tide segments.

As detailed in Section 9, TMDLs have been completed as part of the Chesapeake Bay TMDL for all 92 Chesapeake Bay segments listed in Table 2

- 1 (see Section 9) including the above described three Virginia Bay segments because they flow into impaired tidal Bay segments, and

reductions in nutrient and sediment loadings from their respective watersheds, therefore, are necessary to achieve the Bay jurisdictions‘ Chesapeake Bay WQS.



### 2.2.4 2008 303(d) Listing Segments Compared to Consent Decree and MOU Segments

To ensure that TMDLs were completed for all B ay segments for which they are legally required

— all 2008 listed segments, all Virginia, Delaware, and District of Columbia TMDL consent decree segments, and all Maryland MOU segments

— EPA compared the 2008 listed segments with those included on those agreem ents ( Table 2

- 1 ). In total, 77 segments are addressed by the Virginia and District of Columbia consent decrees and the Maryland MOU: 22 segments are on the Virginia TM DL consent decree; 2 segments are on the Delaware consent decree; 2 segments are on the District of Columbia TMDL consent decree; and 51 segments are on the Maryland TMDL MOU ( Table 2

- 2 ). The evaluation found that all the Virginia consent decree, Delaware consent decree, District of Columbia consent decree, and Maryland MOU segments are a subset of the total list of 92 Chesapeake Bay segments for which TMDLs have

been e stablished under the Bay TMDL.

Table 2

- 2

. Comparison of c onsent d ecree/ MOU segments with total number of Bay segments

Jurisdiction Consent decree or MOU segments Chesapeake Bay segments Virginia 22 35
District of Columbia 2 2

M aryland 51 53

Delaware 2 a 2

Total 77 92

Adapted from Table 2

- 1

. a. Two consent decrees affect one Bay segment each in Delaware

, but TMDLs have already been established for
both segments

.DRAFT Chesapeake Bay TMDL

3

- 1 September 24 , 2010



## SECTION 3. CHESAPEAKE BAY W ATER QUALITY

STANDARDS

WQS consist of four basic elements: designated uses, water quality criteria, an antidegradation policy (to maintain and protect existing uses and high

- quality waters), and general policies (addres sing implementation issues such as low flows, variances, and mixing zones). Designated uses are a jurisdiction‘s goals and expectations for each of the individual surface waters (e.g., coldwater fisheries, public water supply, and primary contact recreatio n). EPA‘s WQS regulation defines designated uses as the ―uses specified in WQS for each waterbody or segment, whether or not they are being attained‖ (40 CFR 131.3). Water quality criteria may be numeric or narrative, and represent a quality of water that supports a particular use. When water quality criteria are met, water quality is expected to protect its designated use. Numeric water quality

criteria are chemical

- specific and are based on specific levels of pollutants consistent with the water‘s designa ted uses (e.g., physical or chemical characteristics like temperature, minimum concentration of DO, and the maximum concentrations of toxic pollutants).

Starting in 1986, EPA and its CBP partners embarked on a process to synthesize scientific

evidence on t he water quality requirements of hundreds of aquatic species and biological communities. The 1987 Chesapeake Bay Agreement includes a commitment to, ―develop and adopt guidelines for the protection of water quality and habitat conditions necessary to suppo rt the living resources found in the Chesapeake Bay system, and to use these guidelines in the implementation of water quality and habitat quality programs‖ ( CEC 1987)

. The CBP partnership initially published two syntheses of the available scientific findings supporting establishment of habitat requirements for 31 target species ( CBP 1987 ; Funderburk et al. 1991)

. Th o se efforts spawned development and publication of synthesis do cuments focused on DO requirements (Jordan et al. 1991) and underwater Bay grasses habitat requirements (Batiuk et al.

199 2 , 2000) . On the basis of that work, in part, EPA published as guidance the Chesapeake Bay

w ater q uality c riteria ( USEPA 2003a) and th e Chesapeake Bay refined aquatic life designated

uses and attainability document ( USEPA 2003c) . Guided by those efforts, Delaware, the District of Columbia, Maryland, and Virginia adopted jurisdiction

- specific Chesapeake Bay WQS regulations in 2004

– 2005 co nsistent with the EPA published guidance. EPA then reviewed and approved the four tidal Bay jurisdictions‘ WQS submissions pursuant to CWA section 303(c).

Maryland, Virginia, and the District have each proposed very specific amendments to their respective Chesapeake Bay WQS regulations. The proposed amendments are described in

Section 3.2.5.



### 3.1 Chesapeake Bay Water Quality Criteria and Designated Uses

The above described DO, underwater Bay grasses and Bay habitat requirement s documents ( Batiuk et al 1992, 2000; CBP 1987; Funderburk et al. 1991; Jordan et al. 1991 ) , supplemented by additional scientific research findings, provided the basis for developing the applicable water quality criteria guidance for the Chesapeake Bay . That guidance is in EPA‘s Bay criteria (USEPA 2003a) and designated uses/attainability (USEPA 2003c) documents and their subsequent addenda ( USEPA 2004a, 2004b, 2004 e , 2005, 2007a, 2007b, 2008 a , 2010 a ). EPA Region 3 published those documents as guidance in accordance wi th CWA s ections 117(b) and 303 to derive water quality criteria specifically for addressing the critical nutrient and sedimentDRAFT Chesapeake Bay TMDL

3

- 2 September 24 , 2010

enrichme nt parameters necessary to protect designated aquatic life uses in the Bay ( Table 3

- 1 ). These criteria serve as surrogate numeric criteria for nitrogen, phosphorus, and sediment.

Table 3

- 1

. Chesapeake Bay water quality criteria an d designated use related documentation and
addenda

Document title Month/year published Document content and description

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributaries

. EPA 903

- R

- 03

- 002. [USEPA 2003a] April 2003 Original Chesapeake Bay water quality
criteria document.

Technical Support Document for Identification of Chesapeake Bay Designated Uses and Attainability . EPA

903

- R

- 03

- 004. [USEPA 2003 c ] October 2003 Original Chesapeake Bay tidal waters designated uses document.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributaries

— 2004 Addendum. EPA 903

- R

03

- 002. [USEPA 2004 a ] October 2004 Address e s endangered species protection,
assessment of DO criteria, derivation of site

specific DO criteria, pycnocline boundary delineation methodology and updated water clarity criteria/SAV restoration acreage assessment procedures.
Technical Support Document for Identification of Chesapeake Bay Designated Uses and Attainability

— 2004
Addendum. EPA 903

- R

- 04

- 006. [USEPA

2004 e ] October 2004 Addresse s refinements to Bay tidal waters designated use boundaries, segmentation boundaries, Potomac River jurisdictional
bo undaries, and document s SAV no

- grow zones, restoration goal

, and shallow

- water

acreages. Chesapeake Bay Program Analytical Segmentation Scheme: Revisions,
Decisions and Rationales 1983

– 2003

. EPA 903

- R

- 0 4

- 00 8 . CBP/TRS 2 68

- 0 4

. [USEPA 2004b] October 2004 Detail s documentation on the history of the segmentation schemes and coordinates, georeferences and narrative descriptions of the 2003 segmentation scheme.

Chesapeake Bay Program Analytical Segmentation Scheme: Revisions,
Decisions and Rationales 1983

– 200 3: 2005
Addendum

. EPA 903

- R

- 0 5

- 00 4 . CBP/TRS

2 78

- 0 6

. [USEPA 2005] December

2005 Addresse s methods used to subdivide the

segments by jurisdiction and the coordinates, georeferences and narrative descriptions for those subdivided segments.

Ambient Water Qual

ity Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributarie s

— 2007 Addendum . EPA 903

- R

07

- 003. CBP/TRS 285

- 07. [USEPA 2007a] July 2007 Addresse s refinements to the Bay water quality DO , water clarity/SA V and chlorophyll

a criteria assessment methodologies and
document s the framework for Bay tidal waters 303(d) list decision making.
Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributaries

— 2007 Chlorophyll Criteria
Addendum . EPA 903

- R

- 07

- 005

. CBP/TRS 288/07. [USEPA 2007 b ] November

2007 Publishe s a set of numerical chlorophyll a

criteria for Chesapeake Bay and the supporting criteria assessm ent procedures.DRAFT Chesapeake Bay TMDL

3

- 3 September 24 , 2010

Document title Month/year published Document content and description

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributaries

— 2008 Technical Support for
Criteria Assessment Protocols Addendum

. EPA 903

- R

- 08

- 001. CBP/TRS 290

- 08. [USE PA 2008 a ] September

2008 Addresse s refinements to the Bay water

quality DO , water clarity/SAV and chlorophyll

a criteria assessment methodologies and
document s the 2008 92

- segment scheme for Bay tidal waters.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal
Tributaries

— 2010 Technical Support for
Criteria Assessment Protocols Addendum

. EPA 903

- R

- 10

- 002. [USEPA 2010 a ] May 2010 Addresse s refinements to procedures for defining designated uses, existing procedures for deriving biological ly based
reference curves for DO criteria assessment and chlorophyll criteria assessment procedures.

Before adoption into each Bay jurisdiction‘s WQS regu lations, each set of criteria, criteria assessment procedures, designated uses, and proposed WQS were subject to extensive scientific, programmatic, and public review.
The original 2003 water quality criteria, assessment procedures, and designated uses wen t through independent scientific peer reviews sponsored by the CBP‘s STAC. The CBP‘s Water Quality Steering Committee‘s water quality criteria and designated use teams then reviewed and approved them. Finally, the CBP‘s Water Quality Steering Committee rev iewed and approved them for EPA publication on behalf of the partnership.

Since the publication of the original Chesapeake Bay w ater q uality c riteria document ( USEPA 2003a) and C hesapeake Bay designated uses and attainability document (USEPA 2003 c ), EPA

ha s published significant changes to the water quality criteria and the criteria assessment procedures. Specifically, EPA has published five addenda

— USEPA 2004a, 2007a, 2007b,

2008 a , 2010 a

— t o the original 2003 Bay criteria document ( USEPA 2003a), one addendu m

— USEPA 2004e

— to the original 2003 Bay designated use/attainability document (USEPA 2003c)

and one addendum

— USEPA 2005

— to the original Bay segmentation document ( USEPA 2004b) (see Table 3

- 1 ).

Those revisions have undergone independent scientific peer reviews, sponsored by the CBP‘s STAC, before review and approval by the CBP‘s Criteria Assessment Protocols Workgroup and then the Water Quality Steering Committee/Water Quality Implementation Team for EPA publication on behalf of the partnership. Examples include the cumulative frequency distribution approach (STAC 2006) and the biological reference curves (STAC 2009).

WQS revisions incorporating the most recent of these addenda are pending in the District of Columbia, Maryland, and Virginia. Virginia‘s WQS revisions also will incorporate the 2007 and

2008 addenda. Maryland, Virginia, Delaware

, and the District of Columbia‘s processes for adopting amendments to their exist ing Chesapeake Bay WQS regulations require full public notice, public review and comment

, and response to public comments before submission to EPA Region 3 for final EPA review and approval.

In this TMDL, EPA is proposing for public notice and comment two separate TMDLs

— one based on current WQS and one based on changes to WQS being proposed by the tidal Bay jurisdictions. Those two sets of WQS are discussed more fully in Sections 3.2 and 3.3 below.DRAFT Chesapeake Bay TMDL

3

- 4 September 24 , 2010



### 3.1.1 Tidal Water Designated Uses

EPA and its seven watersh ed jurisdiction partners agreed on five refined aquatic life designated uses reflecting the habitats of an array of recreationally, commercially, and ecologically important species and biological communities ( USEPA 2003 c , 2004 e , 2010 a ). The five tidal Bay designated uses are applied, where appropriate, consistently across Maryland, Virginia,

Delaware

, and the District of Columbia‘s portions of the Chesapeake Bay a nd its tidal tributary and embayment waters. The vertical and horizontal breadth and temporal a pplication of the designated use boundaries are based on a combination of natural factors, historical records, physical features, hydrology, bathymetry

, and other scientific considerations (USEPA 2003c, 2004e, 2010a). Table 3

- 2 outlines the Chesapeake Bay tidal water designated uses, which are

illustrated in Figure 3

- 1

.

Table 3

- 2

. Five Chesapeake Bay tidal waters designated uses

Tidal water designated use Chesapeake Bay habitats and communities protected

Migra tory fish spawning and

nursery Migratory and resident tidal freshwater finfish during the late winter/spring spawning and nursery season in tidal freshwater to low

salinity habitats.

Shallow

- water bay grass Underwater bay grasses and fish and crab species that depend on the
shallow

- water habitat provided by underwater bay grass beds.
Open

- water fish and shellfish Diverse populations of sport fish, including striped bass, bluefish,
mackerel and sea trout, as well as important bait fish such as
menhaden and silversides in surface water habitats within tidal creeks, rivers, embayments and the mainstem Chesapeake Bay year

- round.

Deep

- water seasonal fish and
shellfish Animals inhabiting the deeper transitional water column and bottom
habitats between the well

- mixed surface waters and the very deep channels during the summer months (e.g., bottom

- feeding fish, crabs and oysters, as well as other important species, including the bay anchovy).

Deep

- channel seasonal refuge Bottom

- sediment

- dwelling worms and small c lams that serve as food
for bottom

- feeding fish and crabs in the very deep channel in summer.

Sources: USEPA 2003 c , 2004 eDRAFT Chesapeake Bay TMDL

3

- 5 September 24 , 2010

Source: USEPA 2003 c

Figure 3

- 1 . Conceptual illustration of the five Chesapeake Bay tidal water designated use zones.

Table 3

- 3 lists the designated uses for each of the 92 Chesapeake Bay segments pursuant to current WQS regulations. 14 It original ly was published as Table V

- 1 on pages 51

– 53 of the Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries 2007 Addendum (USE P A 2007a)

, which is an updated

version of Table IV

- 3 originally published on pages 62

– 63 of the 2003 Technical Support Document for Identification of Chesapeake Bay Designated Uses and Attainability (USEPA 2003c)

. The absence of an X in the shallow

- water bay grass designated use column indicates that

the Ba y segment has been entirely delineated as an SAV no

- grow zone and, therefore, the

shallow

- water B ay grass designated use does not apply to that Bay segment (USEPA 2004e).

14 Maryland is proposing adding the deep

- water designated use to three Bay segments

— MAGMH (Magothy River), SEVMH (Severn Ri ver), and SOUMH (South River)

— as part of a set of proposed amendments to its Chesapeake Bay WQS regulations.DRAFT Chesapeake Bay TMDL

3

- 6 September 24 , 2010

Table 3

- 3 . Current t idal water designated uses by Chesapeake Bay segment

CBP segment

name CBP

segment Juris Migratory

spawning &

nursery Open

water Deep

water Deep

channel Shallow

water

Feb. 1

– May 31 Year

r oun d June 1

–

Sept. 30 June 1

–

Sept. 30 SAV

growing

season Northern Chesapeake Bay CB1TF MD X X X

Upper Chesapeake Bay CB2OH MD X X X

Upper Central Chesapeake Bay CB3MH MD X X X X X

Middle Central Chesapeake Bay CB4MH MD X X X X X

Lower Central Chesapeake Bay CB5MH

_

MD MD X X X X

Lower Central Chesapeake Bay CB5MH

_

VA VA X X X X

Western Lower Chesapeake Bay CB6PH VA X X X

Eastern Lower Chesapeake Bay CB7PH VA X X X

Mouth of the Chesapeake Bay CB8PH VA X X

Bush River BSHOH MD X X X Gunpowder River GUNOH MD X X X

Middle River MIDOH MD X X X

Back River BACOH MD X X X * Patapsco River PATMH MD X X X X Magothy River MAGMH MD X X X

Severn River SEVMH MD X X X

South River SOUMH MD X X X

Rhode River RHDMH MD X X X

West River WSTMH MD X X X Upper Patuxent
River PAXTF MD X X X

Western Branch (Patuxent R.) WBRTF MD X X X *

Middle Patuxent
River PAXOH MD X X X

Lower Patuxent
River PAXMH MD X X X X

Upper Potomac
River POTTF

_

DC DC X X X

Upper Potomac
River POTTF

_

MD MD X X X

Upper Potomac
River POTTF

_

VA VA X X X

Anacostia River ANATF

_

DC DC X X XDRAFT Chesapeake Bay TMDL

3

- 7 September 24 , 2010

CBP segment

name CBP

segment Juris Migratory

spawning &

nursery Open

water Deep

water Deep

channel Shallow

water

Feb. 1

– May 31 Year

r oun d June 1

–

Sept. 30 June 1

–

Sept. 30 SAV

growing

season Anacostia River ANATF

_

MD MD X X X

Piscataway Creek PISTF MD X X X

Mattawoman
Creek MATTF MD X X X

Middle Potomac
River POTOH1 MD X X X

Middle Potomac
River POTOH2 MD X X X

Middle Potomac
River POTOH3 MD X X X

Middle Potomac
River POTOH VA X X X

Lower Potomac
River POTMH MD X X X X X

Lower Potomac
River POTMH VA X X X X X

Upper Rappahannock
River RPPTF VA X X X

Middle Rappahannock
River RPPOH VA X X X *

Lower Rappahannock
River RPPMH VA X X X X X

Corrotoman River CRRMH VA X X X

Piankatank River PIAMH VA X X Upper Mattaponi
River MPNTF VA X X X

Lower Mattaponi
River MPNOH VA X X X *

Upper Pamunkey
River PMKTF VA X X X

Lower Pamunkey
River PMKOH VA X X X *

Middle York River YRKMH VA X X X

Lower York River YRKPH VA X X X Mobjack Bay MOBPH VA X X Upper James
River

- Lower JMSTF1 VA X X X

Upper James
River

- Upper JMSTF2 VA X X X

Appomattox River APPTF VA X X X

Middle James
River JMSOH VA X X X

Chickahominy
River CHKOH VA X X XDRAFT Chesapeake Bay TMDL

3

- 8 September 24 , 2010

CBP segment

name CBP

segment Juris Migratory

spawning &

nursery Open

water Deep

water Deep

channel Shallow

water

Feb. 1

– May 31 Year

r oun d June 1

–

Sept. 30 June 1

–

Sept. 30 SAV

growing

season Lower James
River JMSMH VA X X X

Mouth of the
James River JMSPH VA X X

Western Branch
Elizabeth River WBEMH VA X

Southern Branch
Elizabeth River SBEMH VA X

Eastern Branch
Elizabeth River EBEMH VA X

Lafayette River LAFMH VA X

Mouth of the
Elizabeth River ELIPH VA X X X

Lynnhaven River LYNPH VA X X

Northeast River NORTF MD X X X

C&D Canal C&DOH

_

DE DE X X X

C&D Canal C&DOH

_

MD MD X X X

Bohemia River BOHOH MD X X X

Elk River ELKOH MD X X X

Sassafras River SASOH MD X X X Upper Chester
River CHSTF MD X X X *

Middle Chester
River CHSOH MD X X X

Lower Chester
River CHSMH MD X X X X X

Eastern Bay EASMH MD X X X X Upper Choptank
River CHOTF MD X X

Middle Choptank
River CHOOH MD X X X

Lower Choptank
River CHOMH

2 MD X X X

Mouth of the Choptank River CHOMH

1 MD X X X

Little Choptank
River LCHMH MD X X

Honga River HNGMH MD X X Fishing Bay FSBMH MD X X X Upper Nanticoke
River NANTF

_

MD MD X X

Upper Nanticoke
River NANTF

_

DE DE X X X *

Middle Nanticoke
River NANOH MD X X XDRAFT Chesapeake Bay TMDL

3

- 9 September 24 , 2010

CBP segment

name CBP

segment Juris Migratory

spawning &

nursery Open

water Deep

water Deep

channel Shallow

water

Feb. 1

– May 31 Year

r oun d June 1

–

Sept. 30 June 1

–

Sept. 30 SAV

growing

season Lower Nanticoke
River NANMH MD X X X

Wicomico River WICMH MD X X X

Manokin River MANMH MD X X X Big Annemessex
River BIGMH MD X X X

Upper Pocomoke
River POCTF MD X X

Middle Pocomoke
River POCOH

_

MD MD X X X *

Middle Pocomoke
River POCOH

_

VA VA X X X *

Lower Pocomoke
River POCMH

_MD MD X X X

Lower Pocomoke
River POCMH

_VA VA X X X

Tangier Sound TANMH

_

MD MD X X

Tangier Sound TANMH

_

VA VA X X

An asterisk (*) indicate s that no numerical SAV restoration acreage goal was published in 2003 for the shallow

- water bay grass designated use of that segment (USEPA 2003c)

.



### 3.1.2 Dissolved Oxygen Criteria

Oxygen is one of the most essential environmental constituents supporting life. In the Chesapeake Bay‘s deeper waters, there is a natural tendency toward reduced DO conditions because of the Bay‘s physical morphology and estuarine circulation. The Chesapeake Bay‘s highly productive shallow waters, coupled with strong density stratification ; long residence times (weeks to months) ; low tidal energy ; and tendency to retain, recycle

, and regenerate nutrients from the surrounding watershed all set the st age for low DO conditions.

Against that backdrop, EPA work ed closely with its seven watershed partners and the larger Bay scientific community to derive and publish a set of DO criteria to protect specific aquatic life communities and reflect the Chesapeak e Bay‘s natural processes that define distinct habitats ( Figure 3

- 2 ) ( USEPA 2003a; Batiuk et al. 2009) . Working with the National Marine Fisheries Service, EPA also en sured that the criteria were protective of the shortnose sturgeon, a species listed as endangered by the Endangered Species Act (NMFS 2003)

.DRAFT Chesapeake Bay TMDL

3

- 10 September 24 , 2010

Source: USEPA 2003a

Figure 3

- 2

. DO (mg/L) concentrations required by different Chesapeake Bay species and biological
communities

. Criteria for the migratory fish spawning and nursery, shallow

- water Bay grass and open

- water fish and shellfish designated uses were set at levels to prevent im pairment of growth and to protect the reproduction and survival of all organisms living in the open

- water column habitats ( Table 3

- 4 ) (USEPA 2003a). Criteria for deep

- water seasonal fish and shellfish designated use habitats during seasons when the water column is significantly stratified were set at levels to protect juvenile and adult fish, shellfish, and the recruitment success of the Bay anchovy. Criteria for deep

- channel seasonal refuge designated use habitats in summer were set to protect the

survival of bottom sediment

- dwelling worms and clams.DRAFT Chesapeake Bay TMDL

3

- 11 September 24 , 2010

Table 3

- 4

. Current Chesapeake Bay DO criteria
Designated

use Criteria

con centration/duration Protection provided Temporal application Migratory
fish spawning
and

nursery use 7

- day mean > 6 mg/L

(tidal habitats with 0

– 0.5 ppt salinity) Survival/growth of larval/juvenile tidal

fresh resident fish; protective of threatened/endangered species February 1

– May

31

Instantaneous minimum > 5 mg/L Survival and growth of larval/juvenile migratory fish; protective of threatened/endangered species Open

- water fish and shellfish designated use criteria apply June 1

– January

31
Shallow

water bay

grass use Open

- water fish and shellfish designated use criteria apply Year

- round

Open

- water
fish and
shellfish use 30

- day mean > 5.5 mg/L

(tidal habitats with 0

– 0.5 ppt salinity) Growth of tidal

- fresh juvenile and
adult fish; protective of threatened/endangered species Year

- round

30

- day mean > 5 mg/L (tidal habitats with >0.5 ppt salinity) Growth of larval, juvenile, and adult fish and shellfish; protective of threatened/endangered species

7

- day mean > 4 mg/L Survival of open

- water fish larvae

Instantaneous minimum > 3.2 mg/L Survival of threatened/endangered sturgeon species a Deep

- water
seasonal
fish and
shellfish use 30

- day mean > 3 mg/L Survival and recruitment of Bay anchovy eggs and larvae June 1

– September 30

1

- day mean > 2.3 mg/L Survival of open

- water juvenile and
adult fish

Instantaneous minimum > 1.7 mg/L Survival of Bay anchovy eggs and
larvae Open

- water fish and shellfish designated use criteria apply October 1

– May 31 Deep

channel
seasonal refuge use Instantaneous minimum > 1

mg/L Survival of bottom

- dwelling worms
and clams June 1

– September 30 Open

- water fish and shellfish designated use criteria apply October 1

– May 31

Source: USEPA 2003a Notes: mg/L = milligrams per liter; ppt = parts per thousand salinity a. At temperatures considered stressful to shortnose sturgeon (> 29 degrees Celsius), DO concentrations above an instantaneous minimum of 4.3 mg/L will protect survival of this listed sturgeon species.



### 3.1.3 Chlorophyll a Crite ria

EPA‘s 2003 Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries ( USEPA 2003a) describe s the applicable narrative criteria for chlorophyll a :

Concentrations of chlorophyll a in free

- floating microscopic aquatic plants (algae) shall not exceed levels that result in ecologically undesirable

consequences

— such as reduced water clarity, low dissolved oxygen, food supply imbalances, proliferation of species deemed potentially harm ful to aquatic life or humans or aesthetically objectionable conditions

— or otherwise render tidal waters unsuitable for designated uses.DRAFT Chesapeake Bay TMDL

3

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In 2007 EPA published numeric chlorophyll a criteria guidance protective of open

- water designated use impairment by har mful algal blooms and provided recommended reference chlorophyll a concentrations for historic chlorophyll a levels, and DO and water clarity impairments (USEPA 2007 a).

Delaware, the District of Columbia, Maryland, and Virginia all adopted EPA‘s narrative chlorophyll a criteria. Additionally, Virginia and the District of Columbia adopted EPA‘s numeric chlorophyll a criteria for certain tidal waters as detailed in Section 3.2.



### 3.1.4 Water Clarity/Underwater Bay Grasses Criteria

Underwater B ay grass beds crea te rich animal habitats that support the growth of diverse fish and invertebrate populations. Underwater Bay grasses, also referred to as submerged aquatic vegetation ( SAV ) , help improve tidal water quality by retaining nutrients as plant material,

stabili zing bottom sediments (preventing their resuspension) and reducing shoreline erosion. The

health and survival of such underwater plant communities in the Chesapeake Bay and its tidal tributaries depend on suitable environmental conditions (Dennison et al. 1993; Kemp et al. 2004).

The loss of SAV from the shallow waters of the Chesapeake Bay, which was first noted in the early 1960s, is a widespread, well

- documented problem (Orth and Moore 1983 ; Orth et al. 2010 ). The primary causes of the decline of SAV are nutrient over

- enrichment

, increased suspended sediment in the water, and associated reductions in light availability (Kemp et al

. 2004). T o restore the critical habitats and food sources, enough light must penetrate the shallow waters to support the survival, growth

, and repropagation of diverse, healthy

, SAV communities (Dennison et al. 1993)

.

EPA , working closely with its seven watershed partners and the larger Bay scientific community, derived and published Chesapeake Bay water clarity criteria to establish the minimum level of light penetration required to support the survival, growth

, and continued propagation of SA V (USEPA 2003a) . Chesapeake Bay

- specific water clarity criteria were derived for low and higher salinity habitats u sing a worldwide literature synthesis, an evaluation of Chesapeake Bay

- specific field study findings, and model simulation and diagnostic too ls ( Table 3

- 5 ).

Table 3

- 5

. Summary of Chesapeake Bay water clarity criteria for application to shallow

- water bay

grass designated use habitats

Salinity regime Water clarity

criteria (percent light

through

water) Water clarity criteria as Secchi depth a

Temporal application Water clarity criteria application depths

(meters)

0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 Secchi depth for above criteria application depth

(meters)

Tidal

- fresh 13% 0.2 0.4 0.5 0.7 0.9 1.1 1.2 1.4 April 1

– Oct 31 Oligohaline 13% 0.2 0.4 0.5 0.7 0.9 1.1 1.2 1.4 April 1

– Oct 31

Mesohaline 22% 0.2 0.5 0.7 1.0 1.2 1.4 1.7 1.9 April 1

– Oct 31 Polyhaline 22% 0.2 0.5 0.7 1.0 1.2 1.4 1.7 1.9 March 1

– May 31 Sept 1

– Nov 30

Source: USEPA 2003a

a . Based on application of the Equation IV

- 1published in USEPA 2003a, PLW = 100exp(

- K d Z), where the appropriate percent light through water (PLW) criterion value and the selected application depth (see Table 3

- 6) are inserted andDRAFT Chesapeake Bay TMDL

3

- 13 September 24 , 2010

the equation is solved for K d . The generated K d value is then converted to Secchi depth (in meters) using the

c onversion factor K d = 1.45/Secchi depth.

The water clarity criteria, applied only during the SAV growing seasons, are presented in terms of the percent ambient light at the water surface extending through the water column and the equivalent Secchi depth b y application depth ( Table 3

- 5 ). The recommended percent light

through

- water criteria can be directly measured using a Secchi disk or a light meter. A specific applic ation depth is required to apply and determine attainment of the water clarity criteria ( Table 3

- 6 )

.
SAV restoration acreage goals and water clarity application depths were developed based on

historic and recent data on the distribution of SAV ( USEPA 2003c ). Detailed analyses using th at
data

— including historical aerial photographs

— were undertaken to map the distribution and depth of historical SAV beds in the Chesapeake Bay and its tidal tributaries. The analyses led to the adoption of the single best year method that considers historical SAV distributions from the

1930s through the early 1970s and more recent distributions since 1978 to the pre sent mapped through annual SAV aerial surveys of the Bay‘s shallow

- water habitats

. Using th at method, the

CBP and its watershed partners established a B ay

- wide SAV restoration goal of 185,000 acres and Bay segment

- specific acreage goals ( Table 3

- 6 ) (USEPA 2003c).

Table 3

- 6

. Chesapeake Bay SAV restoration acreages and application depths

— current WQS
Segment description State Segment designator SAV acreage

restoration goal Secc h i

application depth (meters) Northern Chesapeake Bay MD CB1TF2 12,149 2.0 Northern Chesapeake Bay MD CB1TF1 754 1.0 Upper Chesapeake Bay MD CB2OH 705 0.5 Upper Central Chesapeake Bay MD CB3MH 1,370 0.5 Middle Central Chesapeake Bay MD CB4MH 2,533 2.0 Lower Central Chesapeake Bay MD CB5MH _MD 8

, 270 2.0 Lower Central Chesapeake Bay VA CB5MH _VA 7,633 2.0 Western Lower Chesapeake Bay VA CB6PH 1,267 1.0 Eastern Lower Chesapeake Bay VA CB7PH 15,107 2.0 Mouth of Chesapeake Bay VA CB8PH 11 0.5

Bush River MD BSHOH 350 0.5 Gunpowder River

- Upper MD GUNOH2 572 2.0 Gunpowder River

- Lower MD GUNOH1 1,860 0.5

Middle River MD MIDOH 879 2.0

Back River MD BACOH 340 15 0.5 Patapsco River MD PATMH 389 1.0 Magothy MD MAGMH 579 1.0

Severn River MD SEVMH 455 1.0

South River MD SOUMH 479 1.0

Rhode River MD RHDMH 60 0.5

West River MD WSTMH 238 0.5 Upper Patuxent River MD PAXTF 205 0.5

Middle Patuxent River MD PAXOH 115 0.5

15 Proposed revisions to Maryland‘s water quality standards regulations would revise this figure to 30 acres.DRAFT Chesapeake Bay TMDL

3

- 14 September 24 , 2010

Segment description State Segment designator SAV acreage

restoration goal Secc h i

application depth (meters)

Lower Patuxent River MD PAXMH1 1,459 2.0

Lower Patuxent River MD PAXMH2 172 0.5

Lower Patuxent River MD PAXMH4 1 0.5

Lower Patuxent River MD PAXMH5 2 0.5 Upper Potomac River MD POTTF _MD 2

, 142 2.0 Piscataway Creek MD PISTF 789 2.0

Mattawoman Creek MD MATTF 792 1.0

Middle Potomac River MD POTOH1 1

, 387 2.0

Middle Potomac River MD POTOH2 262 1.0

Middle Potomac River MD POTOH3 1,153 1.0

Lower Potomac River MD POTMH _MD 7

, 088 1.0 Upper Potomac River VA POTTF _VA 2,093 2.0

Middle Potomac River VA POTOH _VA 1,503 2.0

Lower Potomac River VA POTMH _VA 4,250 1.0 Upper Rappahannock River VA RPPTF 66 0.5 Middle Rappahannock River VA RPPOH 4 0.5 Lower Rappahannock River VA RPPMH 1

, 700 1.0

Corrotoman River VA CRRMH 768 1.0

Piankatank River VA PIAMH 3,479 2.0 Upper Mattaponi River VA MPNTF 85 0.5 Lower Mattaponi River VA MPNOH No Data
Available 0.5

Upper Pamunkey River VA PMKTF 187 0.5 Lower Pamunkey River VA PMKOH No Data
Available 0.5

Middle York River VA YRKMH 239 0.5

Lower York River VA YRKPH 2,793 1.0 Mobjack Bay VA MOBPH 15,901 2.0 Upper James River

- Upper VA JMSTF2 200 0.5 Upper James River

- Lower VA JMSTF1 1

, 000 0.5 Appomattox River VA APPTF 379 0.5

Middle James River VA JMSOH 15 0.5 Chickahominy River VA CHKOH 535 0.5

Lower James River VA JMSMH 200 0.5

Mouth of the James River VA JMSPH 300 1.0 Lynnhaven River VA LYNPH 107 0.5

Northeast River MD NORTF 89 0.5 Chesapeake & Delaware Canal MD C&DOH _MD 7 0.5

Bohemia River MD BOHOH 354 0.5

Elk River MD ELKOH1 1,844 2.0

Elk River MD ELKOH2 190 0.5

Sassafras River MD SASOH1 1,073 2.0

Sassafras River MD SASOH2 95 0.5 Upper Chester River MD CHSTF 230 16 0.5

16 Proposed revisions to Maryland‘s wat er quality standards regulations would revise this figure to 1 acre.DRAFT Chesapeake Bay TMDL

3

- 15 September 24 , 2010

Segment description State Segment designator SAV acreage

restoration goal Secc h i

application depth (meters)

Middle Chester River MD CHSOH 77 0.5

Lower Chester River MD CHSMH 2,928 1.0 Eastern Bay MD EASMH 6,209 2.0 Middle Choptank River MD CHOOH 72 0.5 Lower Choptank River MD CHOMH2 1,621 1.0 Mouth of Choptank River MD CHOMH1 8,184 2.0 Little Choptank River MD LCHMH 4,076 2.0 Honga River MD HNGMH 7,761 2.0 Fishing Bay MD FSBMH 197 0.5

Middle Nanticoke River MD NANOH 12 0.5

Lower Nanticoke River MD NANMH 3 0.5

Wicomico River MD WICMH 3 0.5

Manokin River MD MANMH1 4,294 2.0

Manokin River MD MANMH2 59 0.5 Big Annemessex River MD BIGMH1 2,021 2.0 Big Annemessex MD BIGMH2 22 0.5

Middle Pocomoke River MD POCOH_MD 22 17 0.5

Lower Pocomoke River MD POCMH _MD 877 1.0

Lower Pocomoke River VA POCMH _VA 4,066 1.0 Tangier Sound MD TANMH1 _MD 24

, 683 2.0 Tangier Sound MD TANMH2 _MD 74 0.5 Tangier Sound VA TAHMH_VA 13,579 2

Sources: USEPA 2003c, 2004e; Code of Maryland Title 26 Subtitle 08, Chapter 2, Section 3; Code of Virginia 9 62.1

- 44.15 3a ; VAC 25

- 260

- 185; 7 Delaware Code Section 6010; 7 Delaware Administrative Code 7401; D istrict of
C olumbia Municipal Regulations Title 21, Chapter 11

. Note: This table contains additional split segments beyond the 92 Chesapeake Bay segments listed in Table 3

- 3 strictly for purposes of applying separate water clarity criteria application depths within the same segment (USEPA 2004e).



### 3.2 Jurisdictions’ Current Chesapeake Bay Water Quality Standards Regulations

Delaware, the District of Columbia, Maryland, and Virginia eac h has adopted WQS consistent with EPA‘s published Chesapeake Bay water quality criteria, assessment procedures, and tidal water designated uses in its respective WQS regulations ( Table 3

- 7 ). In some cases, a jurisdiction also has adopted more jurisdiction

- specific designated uses or criteria or both; those cases are briefly described below.

17 Proposed revisions to Maryland‘s water quality standards regulations would revise this to be a no

- grow zone.DRAFT Chesapeake Bay TMDL

3

- 16 September 24 , 2010

Table 3

- 7 . Links for accessing t he current WQS regulations for Delaware, the District of Columbia, Maryland, and Virginia

Jurisdiction WQS regulations URL address

Delaware 7 Delaware Code Section 6010; 7 Delaware Administrative Code 7401

< http://www.epa.gov/waterscience/standards/wqslibrary/de/de_3_wqs.pdf >

District of
Columbia DC Municipal Regulations Title 21, Chapter 11

< http://www.epa.gov/waterscience/standards/wqslibrary/dc/dc_3_register.pdf > Maryland Code of Maryland Title 26 Subtitle 08, Chapter 2

< http://www.epa.gov/waterscience/st andards/wqslibrary/dsd.state.md/md

- ch2

- quality

- 20051130.pdf.us/comar/subtitle_chapters/26_Chapters.htm > Virginia Code of Virginia 9 62.1

- 44.15 3a ; VAC 25

- 260 Virginia WQS s

< http://www.deq.virginia.gov/wqs/ > OR

< http://epa.gov/waterscience/standards/wqslibrary/va/va_3_wqs.pdf >



### 3.2.1 District of Columbia

Table 3

- 8 summarizes the District of Columbia‘s designated uses for its s urface waters. The District of Columbia has adopted EPA‘s narrative chlorophyll a water quality criteria but also adopted the Bay n umeric chlorophyll a water quality criteria shown in Table 3

- 9 with respect to

the District of Columbia‘s tidal Class C waters. Those numeric chlorophyll a criteria are subject to this Chesapeake Bay TMDL (see Table 2

- 1 )

.

Table 3

- 8 . District of Columbia designated uses for surface waters

Class of water Description

A Primary contact recreation

B Secondary contact recreation and aesthetic enjoyment

C Protection and propagation of fish, shellfish, and wildlife

D Protection of human health related to consumption of fish and shellfish

E Navigation

Source: D istrict of C olumbia Municipal Regulations Title 21, Chapter 11

Table 3

- 9

. Numeric criteria for the District of Columbia’s tidally influenced waters

Constituent Numeric c riteria Temporal

a pplication Designated

u se Dissolved

oxygen 7

- day mean ≥ 6.0 mg/L

Instantaneous minimum ≥ 5.0 mg/L

30

- day mean ≥ 5.5 mg/L

7

- day mean ≥ 4.0 mg/L Instantaneous minimum ≥ 3.2 mg/L (At temperatures greater than 29 °C, in tidally influenced waters, an instantaneous minimum dissolved oxygen concentration of 4.3 mg/L will apply) February 1

– May 31

June 1

– January 31 C

Secchi depth 0.8 m (seasonal segment average) April 1

– October 31 C

Chlorophyll a 25 μg/L (season segment average) July 1

– September 30 C

Source: District of Columbia Municipal Regulations Title 21, Chapter 11

Note: μ g/L = micrograms per literDRAFT Chesapeake Bay TMDL

3

- 17 September 24 , 2010



### 3.2.2 Delaware

The EPA

- published Chesapeake Bay criteria and designated use documents and subsequent addenda apply to the tidal Nanticoke River and Broad Creek in Delaware, both of which are subject to this Chesapeake Bay TMDL (see Table 2

- 1 ). Delaware has adopted EPA‘s narrative chlorophyll a water quality criteria.

Delaware has adopted all the EPA

- published Chesapeake Bay criteria and designated use documents and subsequent addenda listed in Table 3

- 1 by reference into its WQS regulations. As a result, no WQS changes are pending in Delaware.



### 3.2.3 Maryland

Maryland has adopted into its WQS regulations all the EPA

- published Bay criteria, assessment

proce dures, and designated uses described previously to apply to all Chesapeake Bay, tidal tributary, and embayment waters of Maryland subject to this Chesapeake Bay TMDL. Maryland has adopted EPA‘s narrative chlorophyll a water quality criteria.

Several tidal Bay segment

- specific applications of DO criteria are unique to Maryland. In the

middle

- central Chesapeake Bay segment (CB4MH), restoration variances 18 of 7 and 2 percent apply to the application of the deep

- water and deep

- channel designated use DO criteria, respectively. In the Patapsco River segment (PATMH), a restoration variance of 7 percent applies to the application of the deep

- water criteria (COMAR 26.08.02.03

- 3(c)(8)(e)(vi). Such

restoration variances are consistent with EPA

- published guidance (USEPA 2003c) and were approved by EPA on August 29, 2005.



### 3.2.4 Virginia

The EPA

- published Bay criteria, assessment procedures, and designated uses described previously apply to all Chesapeake Bay, tidal tributary, and embayment waters of Virginia and are subjec t to this Chesapeake Bay TMDL. The narrative chlorophyll a criteria guidance published by EPA (USEPA 2003a) as adopted by Virginia are applicable to Virginia‘s Bay tidal waters. Virginia also adopted the segment

- specific numeric chlorophyll a criteria for the tidal

James River listed in Table 3

- 10 into its WQS regulations

. The criteria are based on various scientific lines of evidence published the original EPA 2003 Ba y criteria document ( USEPA 2003a) with additional river

- specific considerations (V ADEQ 2004). EPA approved the WQS regulations on June 27, 2005.

Virginia has additional site

- specific DO and chlorophyll a criteria. In the tidal Mattaponi (MPNTF, MPNOH) and Pamunkey (PMKTF, PMKOH) r iver segment s , b ecause of the seasonal

lower DO concentration from the natural oxygen

- depleting processes present in surrounding tidal

wetlands , a site

- specific criterion of greater than or equal to 4 mg/L 30

- day mean DO ( 9 VA C

25

- 260

- 185 ) is warranted and is consistent with the EPA

- published criterion (USEPA 2004a).

18 A restoration variance is the percentage of allowable exceedance based on water quality modeling incorporating the best available data and assumptions. The restoration variances are temporary and will be reviewed at a minimum every 3 years, as required by the CWA and EPA regulations. The variances could be modified on the basis of new data or assumptions incorporated into the water quality model. COMAR 26.08.02.03

- 3(C)(8)(h).DRAFT Chesapeake Bay TMDL

3

- 18 September 24 , 2010

Table 3

- 10 . Segment

- specific chlorophyll a criteria for Virginia’s tidal James River waters

Designated

u se Chlorophy ll a

criterion ( μg/ L) Chesapeake Bay s egment Temporal

a pplication Open

Water 10 Upper James River

- Upper (JMSTF2) March 1

– May

31 15 Upper James River

- Lower (JMSTF1)

15 Middle James River (JMSOH)

12 Lower James River (JMSMH)

12 Mouth of the James River (JMSPH)

15 Upper James River

- Upper (JMSTF2) July 1

– September 30 23 Upper James River

- Lower (JMSTF1)

22 Middle James River (JMSOH)

10 Lower James River (JMSMH)

10 Mouth of the James River (JMSPH)
Source: Code of Virginia 9 section 62.1

- 44.15 3a ; VAC 25

- 260
Note: μ g/L = micrograms per liter



### 3.3 Jurisdictions’ Pending Revisions to Chesapeake Bay Water Quality Standards Regulations

Maryland, Virginia, and the District of Columbia are each in the process of proposing the

modification of their respective WQS regulations directly relevant to the Bay TMDL.



### 3.3.1 District of Columbia

T he District of Columbia has adopted the 2003 Chesapeake Bay w ater q uality c riteria document ( USEPA 2003a) into its WQS regulations

. The District of Columbia has proposed adoption of

the EPA

- published 2004, 2007, 2008, 2010 Bay criteria addenda (USEPA 2004a, 2007a, 2007b, 2008a, 2010a) by reference. The proposal is pending public review and EPA approval.



### 3.3.2 Delaware

Delaware already has adopted the EPA

- publi shed 2010 Bay criteria addendum into its WQS regulations by reference. Therefore, no revisions to Chesapeake Bay WQS regulations are pending in Delaware.



### 3.3.3 Maryland

Maryland has adopted most of the EPA

- published Chesapeake Bay criteria and designated use documents and subsequent addenda listed in Table 3

- 1 by reference into its W QS regulations. Maryland has proposed adoption of the EPA published 2010 Bay criteria addendum (USEPA 2010a) by reference. The proposal is pending public review and EPA approval.

Maryland also has proposed the following amendments to its WQS regulations: adopting the

EPA

- published 2010 Bay criteria addendum; adopting a 14 percent restoration variance for the lower Chester River segment (CHSMH) deep

- channel DO criteria application; adopting a site

specific 4 mg/L 30

- day mean DO criterion for the upper and m iddle tidal Pocomoke River (POCTF, POCOH_MD) segments; applying the deep

- water designated use, in the presence of observed pycnoclines, in the South (SOUMH), Severn (SEVMH) and Magothy (MAGMH) river
segments; a 30

- acre SAV restoration acreage for the Back River (BACOH) segment; a 1

- acre SAV restoration acreage for the upper Chester River (CHSTF) segment; and recognizing theDRAFT Chesapeake Bay TMDL

3

- 19 September 24 , 2010

middle Pocomoke River segment (POCOH_MD) as an SAV no

- grow zone (Appendix R

- 3). The

prop osal is pending public review and EPA approval.



### 3.3.4 Virginia

Virginia has adopted most of the EPA

- published Chesapeake Bay criteria and designated use documents and subsequent addenda listed in Table 3

- 1 by reference into its WQS regulations. Virginia has proposed adoption of the EPA

- published 2007, 2008, and 2010 Bay criteria addendum (USEPA 2010a) by reference. The proposal is pending public review and EPA approval.



### 3.4 Assessing Attainment of Chesapeake Bay Water Quality
Standards

The Bay criteria assessment approach is designed to protect the living resources as defined by the designated uses (USEPA 2003a). The criteria levels themselves were largely based on

scien tific studies performed in laboratory settings or under controlled field conditions. The criteria establish the level of a given habitat condition that living resources need for survival. They do not account for many other environmental factors that could affect survival.

For all three tidal states and the District of Columbia, attainment of each jurisdiction‘s Chesapeake Bay WQS is determined by applying the same set of assessment procedures published in the original 2003 Chesapeake Bay criteria document ( USEPA 2003a) and subsequent published addenda (USEPA 2004a, 2007a, 2007b, 2008a, 2010a) (see Table 3

- 1 ). Those consistent sets of criteria assessment procedures are f ormally adopted into each jurisdiction‘s WQS regulations by reference.



### 3.4.1 Defining Total Exceedances

Criteria attainment for DO, water clarity, and chlorophyll a is assessed in terms of the spatial and temporal extent of criterion exceedances

— what volum e or surface area of the Bay segment exceeds a given criteria and for how much time during the assessment period (USEPA 2003a, 2004a). T he allowable frequency with which criteria can be violated without a loss of the designated use is also considered

. For each listing cycle, assessments are based on monitoring

data collected over a 3

- year period in each s patial a ssessment u nit. Spatial a ssessment u nits are defined by Chesapeake Bay s egments and applicable d esignated u ses . Such assessment of the

criteria as further described below is designed to provide reliable protection for the associated refined aquatic life use.

The spatial exceedances of criteria are determined using a grid cell

- based data interpolation software application that enables estimation of wa ter quality values for the entire Bay using monitored data at specific points (USEPA 2003a, 2007a). The interpolated data are compared to water quality criteria on a cell by cell basis, and the percent of surface area or volume exceeding

the criterion in e ach spatial assessment unit is calculated. The percent spatial exceedances for each assessment unit are then compiled for each monitoring event conducted during the 3

- year monitoring period.

The temporal extent of exceedances is determined by calculating t he probability that an observed percent exceedance will be equaled or exceeded. To calculate that probability, the percent ofDRAFT Chesapeake Bay TMDL

3

- 20 September 24 , 2010

spatial exceedances are sorted and ranked, and a cumulative probability is calculated for each spatial exceedance value (USEPA 200 3a). An example is shown in Table 3

- 11

.

Table 3

- 11

. Estimated percent spatial criteria exceedance s and associated cumul ative probabilities

Period of data Percent area/volume

exceeding criteria (spatial) Rank Cumulative probability [rank / (n + 1)] (temporal)

100 0.00%

June 1998 75 1 7.69%

March 1998 72 2 15.38% May 1999 67 3 23.08% May 1998 65 4 30.77% April 1998 55 5 38.46%

June 2000 50 6 46.15%

March 1999 49 7 53.85% April 2000 39 8 61.54% May 2000 35 9 69.23% Apr 1999 34 10 76.92%

June 1999 25 11 84.62%

March 2000 20 12 92.31%

Source: USEPA 2003a
The spatial and temporal exceedance s can be graphically illustrated by plotting the cumulative frequency distribution (CFD) curve, which is a plot of the temporal exceedance values on the Y

axis v ersu s the spatial exceedance values on the X

- axis ( Figure 3

- 3) (USEPA 2003a, 2007 a ; STAC 2006).

Source: USEPA 2003a

Figure 3

- 3 . Example cumulative frequency distribution (CFD) curve

.DRAFT Chesapeake Bay TMDL

3

- 21 September 24 , 2010



### 3.4.2 Defining Allowable Exceedances

Reference curves were developed to provide a scientifically based, direct measure of the

allowable criteria exceedances (USEPA 2003a). Those allowable exceedances are defined to be those that last a short enough time or cover a small enough volume/surface area to have no adverse effects on the designated use. It is assumed that the designated uses can be attained even with some limited level of criteria exceedances and thus, the reference curves define those

criteria exceedances deemed to be allowable

— chron ic in time but over small volumes/surface areas, or infrequent occurrences over large volumes/surface areas. Exceedances that occur over large areas of space and time would be expected to have significant detrimental effects on biological communities, whic h would imply nonattainment of designated uses.

Reference curves are used in conjunction with the CFD to illustrate the time and space during which a given criteria can be allowably exceeded without resulting in harm to the designated use. For assessment p urposes, two types of reference curves are used: a biological reference curve and a 10 percent default reference curve.

Biological reference curves are CFDs developed for a given criterion in areas for which monitoring data are available and in which healt hy aquatic communities exist (USEPA 2003a). They represent the range of conditions that can reasonably be expected in a healthy community. As a result, the biological reference curve can be used to provide an understanding of what level

of criteria exceeda nces are allowable without losing support of the designated use. Given the Bay‘s nutrient

- enriched status, appropriate reference sites are limited. Biological reference

curves have been published for and are used to assess allowable exceedances for the deep

- water
DO criteria (USEPA 2010 a ) and the water clarity criteria (USEPA 2003a).

In some cases, developing a biologically based reference curve is not possible because of a lack of data describing the heal th of the relevant species or biological communities and lack of appropriate reference sites . Such cases require a different approach. EPA recommends using a default reference curve in situations for which a biologically based reference curve is unavailabl e (USEPA 2007a). The default reference curve is defined as a hyperbolic curve that encompasses no more than 10 percent of the area of the CFD graph (percent of space multiplied by percent of time) (USEPA 2007a, page 13, Figure II

- 4 and Equation 1) ( Figure 3

- 4 ).DRAFT Chesapeake Bay TMDL

3

- 22 September 24 , 2010

Source: USEPA 2007a

Figure 3

- 4 . Default reference curve used in the attainment assessment of C hesapeake Bay water quality

criteria for which biological ly based reference curves have not yet been derived.

Once the CFD curve for a spatial assessment unit is developed from monitoring data (also referred to as the assessment curve), it is compared to t he appropriate reference curve. The area on the graph above the reference curve and below the assessment curve is considered a non

allowable exceedance. Values on the assessment curve falling below the reference curve are considered allowable exceedances ( Figure 3

- 5 ).DRAFT Chesapeake Bay TMDL

3

- 23 September 24 , 2010

Source: USEPA 2003a

Figure 3

- 5 . Example reference and assessment curves showing allowable and non
- allowable exceedances



### 3.4.3 Assessing Criteria Attainment

Dissolved Oxygen Criteria Assessment
EPA published DO criteria protective of migratory and spawning, open

- water, deep

- water, and deep

- channel designated use habitats (

Table 3

- 4 ) ( USEPA 2003a ). DO criteria were established for Chesapeake Bay that varied in

space and time to provide levels of protection for different key species and communities. The

criteria w ere also designed around several lengths of time to reflect the varying oxygen tolerances for different life stages (e.g., larval, juvenile, adult) and effects (e.g., mortality, growth, behavior).

The DO criteria include multiple components , including a ta rget DO concentration, the duration of time over which the concentration is averaged, the designated use area where the criterion applies, the protection provided, and the time of year when the criterion applies (USEPA 2003a, 2003c). The four tidal Bay jur isdictions adopted these DO criteria into their respective WQS regulations.DRAFT Chesapeake Bay TMDL

3

- 24 September 24 , 2010

Assessing DO criteria attainment is challenging because of the complexity of both the criteria and the Bay itself. To fully assess all the criteria components, data need ed to be collected at a spatial intensity that adequately represent the four designated use habitats of Chesapeake Bay

tidal waters at different times of the year ( USEPA 2003c, 2004 e ). Similarly, data were collected during all the applicable seasons and at frequencies sufficient to address the various criteria

duration components. The different DO criteria apply to different designated use areas and multiple criter ia apply to the same designated use area. The DO criteria components also apply

over different periods to protect species during critical life stages or during particularly stressful

times of the year. To fully assess each DO component in each designated use habitat over the appropriate periods will require an extensive monitoring program and a deta iled assessment methodology. The CBP conducts extensive water quality and living resource monitoring throughout the Bay tidal waters ( CBP 1989 a, 1989b; MRAT 2009 ). The existing Bay water quality monitoring was not sufficient to cover all the criteria compo nents, however, and some

details in the assessment methodology remain unresolved ( USEPA 2007a ; MRAT 2009)

.

The DO criteria include 30

- day, 7

- day, and 1

- day means along with an instantaneous minimum. The CBP partners have the capacity (data, assessment meth odology) to assess only the 30

- day

mean open

- water and deep

- water DO criteria and, in the case of the deep

- channel use, the

instantaneous minimum DO criteria (USEPA 2003a, 2004 a , 2007a, 2008 a , 2010 a ). The remaining DO criteria are not assessed because the existing water quality monitoring programs and the published assessment methodologies are not yet adequate for full assessment.

Evaluation of Chesapeake Bay water quality/sediment transport model outputs have provided

clear evidence that the 30

- day mean op en

- water and deep

- water and the instantaneous minimum deep

- channel DO criteria are the criteria driving determination of nutrient loadings supporting attainment all the open

- water (30

- day mean, 7

- day mean, instantaneous minimum), deep

- water (30

- day mean, 1

- day and instantaneous minimum), and deep

- channel (instantaneous minimum)

DO criteria.

For both open

- water and deep

– water designated uses, the 30

- day mean criteria had the highest nonattainment in all three scenarios ( Figure 3

- 6 ). The 30

- day mean open

- water and deep

- water criteria are, therefore, protective of the other two non

- assessed dissolved oxygen criteria (open

water 7

- day and instantaneous minimum, deep

- water 1

- day mean and instantaneous minimum) on average for the mainstem Bay segments. The deep

– channel designated use has only one dissolved oxygen criterion, and it is currently assessed using monitoring data. The deep

- channel criterion is also more protective, based on the levels of nonattainment recorded in Figure 3

- 6, than the deep

- water and open

- water criteria. The analyses documented in Appendix D provide

clear evidence the 30

- day mean open

- water and deep

- water dissolved oxygen criteria and the deep

- channel instantaneous minimum criterion are the most protective criteria across all Bay segments and designated uses.DRAFT Chesapeake Bay TMDL

3

- 25 September 24 , 2010 Figure 3

- 6

. Direct model assessment of open water (a)

, and deep water and deep channel (b) c riteria

. Chlorophyll a Criteria Assessment
The procedures described in USEPA 2007b, and further refined in USEPA 2010a, apply to assessing Virginia‘s tidal James River and the District of Columbia‘s tidal waters numeric chlorophyll a criteria.

To assess at tainment of the Virginia and District of Columbia‘s adopted numerical chlorophyll a concentration

- based criteria, it was necessary to establish a reference curve for use in the CFD criteria assessment (USEPA 2003a, 2007a). In the case of the numerical chlo rophyll a criteria where a biologically based reference curve is not available (USEPA 2007b) , EPA 0.0% 0.1% 0.2% 0.3% 0.4% 0.5% 0.6% 0.7% 0.8% 0.9% 1.0%

Calibrated Model Moderate Reduction Large Reduction Average Mainstem Non - Attainment Direct model assessment of nonattainment

— mainstem average open water

DO Open Water Summer Instantaneous

DO Open Water Weekly

DO Open Water Summer Monthly

0% 5% 10% 15% 20% 25% 30%

Calibrated Model Moderate Reduction Large Reduction Average Mainstem Non - Attainment Direct model assessment of nonattainment

— mainstem average deep water and deep channel

DO Deep Water Instantaneous

DO Deep Water Daily

DO Deep Water Monthly

DO Deep Channel InstantaneousDRAFT Chesapeake Bay TMDL

3

- 26 September 24 , 2010

recommended

— and Virginia and the District of Columbia adopted

—using the default reference curve originally described in USEPA 2007a and illustrated in Figure 3

- 4

.
The jurisdiction

- adopted, concentration

- based, chlorophyll a criteria values are threshold concentrations that should be exceeded infrequently (e.g., < 10 percent) because a low number of

na turally occurring exceedances occur even in a healthy phytoplankton population (USEPA 2007b). The assessment of chlorophyll a criteria attainment, therefore, uses the CFD

- based assessment method described earlier that applies the default reference curve. S uch concentration

based Chesapeake Bay chlorophyll a criteria apply only to those seasons and salinity

- based habitats for which they were defined to protect against applicable human health and aquatic life impairments (USEPA 2007b). Each season

— Spring (Mar ch 1

– May 31) and Summer (July 1

– September 30)

— was assessed separately to evaluate chlorophyll a criteria attainment.

The chlorophyll a criteria are based on seasonal mean of observed chlorophyll data

. The observed data are first transformed by taking the n atural logarithm and then interpolated spatially to equally spaced points (representing interpolator cells) within the designated use area for each monitoring cruise

. The interpolated value of each cell is averaged in time across the entire

season
, and the n the spatial violation rate is calculated as the fraction of interpolator cells in a designated use area that fail s the appropriate criterion (USEPA 2010a).

SAV/Water Clarity Criteria Assessment
Water clarity criteria and SAV restoration acreages are used to define attainment of the shallow

water bay grass designated use in Chesapeake Bay, its tidal tributaries

, and embayments (USEPA 2003a, 2003c) . EPA published three measures for assessing attainment of the shallow

water SAV designated use for a Chesapeak e Bay segment (USEPA 2007a) :

1. Measure SAV acreage in the Bay segment from overflight data mapping analysis and compare with the SAV restoration goal acreage for that Bay segment ( USEPA 2003b).

2. Measure water clarity acreage on the basis of routine water qual ity mapping using data from the Chesapeake Bay shallow

- water monitoring program and , combined with measured acres of SAV, compare with the calculated water clarity acres for that segment ( USEPA 2007a).

3. Measure water clarity criteria attainment on the basis of the CFD assessment methodology, again using shallow

- water monitoring program data ( USEPA 2003a, 2003 c , 2007a, 2008 a ).

Without sufficient shallow

- water monitoring data to determine the available water clarity acres (measurement 2 above) or to assess water clarity criteria attainment using the CFD

- based procedure (measurement 3 above) , EPA recommends that the jurisdictions assess shallow

- water Bay grass designated use attainment using the acres of mapped SAV (measurement 1 above) ( USEPA 2003a, 2003b, 2 007 a , 2008 a ).