Clean Water Act Section 303(d): Notice for the Establishment of Total Maximum Daily Load (TMDL) for the Chesapeake Bay

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Clean Water Act Section 303(d): Notice for the Establishment of the Total Maximum Daily Load (TMDL) for the Chesapeake Bay


Environmental Protection Agency (EPA).


Notice of Availability of the Chesapeake Bay TMDL.


This notice announces EPA's establishment of the Chesapeake Bay (Bay) TMDL on December 29, 2010 for nitrogen, phosphorus and sediment for the Chesapeake Bay and its tidal tributaries. EPA provided a 45-day public review of the Draft Bay TMDL which was held from September 24 through November 8 of 2010. Based on comments and information EPA received from the public and affected jurisdictions during the public review period, EPA has revised the draft TMDL as appropriate and established the Bay TMDL for nitrogen, phosphorus and sediment for each of the 92 segments in the tidal portion of the Chesapeake Bay watershed pursuant to Sections 117(g) and 303(d) of the Clean Water Act (CWA). The TMDL provides pollutant loads for nitrogen, phosphorus and sediment which can enter a waterbody without causing a violation in the water quality standards. The TMDL allocates that pollutant load between point and nonpoint sources. The Bay TMDL contains segment specific point (wasteload) and non-point (load) allocations for nitrogen, phosphorus and sediment that when met will assure the attainment and maintenance of all applicable water quality standards for each of the 92 segments. The Bay TMDL is a key part of the clean water commitment in the Federal Strategy developed as part of Executive Order 13508 on Chesapeake Bay Protection and Restoration. EPA has worked closely with its federal partners, the six watershed states, the District of Columbia, local governments and other parties to put in place a comprehensive, transparent and accountable set of commitments and actions that together ensure that pollution controls needed to restore Bay water quality are implemented by no later than 2025 (Executive Order, 13508).

Additional information on the Bay TMDL can be found at:

Viewing: The TMDL can be viewed at, in person at EPA Region III, 1650 Arch Street, Philadelphia, PA 19103 with proper arrangements made in advance with the Region 3 library (215-814-5254 or or at the EPA Chesapeake Bay Program Office at 410 Severn Avenue, Suite 112, Annapolis, MD 21403 (Contact Debbie Embleton 410-267-9856 or

Supplementary Information

Section 303(d) of the CWA requires that each state identify those waters within its boundaries for which existing technology-based and other pollution controls required by the CWA are not stringent enough to attain or maintain state water quality standards. A TMDL must be established for each of those “impaired” waters. TMDLs are pollution budgets designed to identify necessary reductions of pollutant loads to the impaired waters so that the appropriate water quality standards are met, including designated uses like fishing or swimming and water quality criteria for parameters such as dissolved oxygen and water clarity.

Background: EPA solicited comments on the Draft Bay TMDL during a 45-day public review of the TMDL which was held from September 24 through November 8 of 2010. During the review period EPA held 18 public meetings and webinars throughout the watershed to assist the public in their understanding of the draft TMDL. Based on comments EPA received from the public and affected jurisdictions during the public review period, as well as watershed implementation plans submitted by the jurisdictions, EPA has revised the draft TMDL as appropriate and is establishing the Bay TMDL for nitrogen, phosphorus and sediment for each of the 92 segments in the tidal portion of the Chesapeake Bay watershed pursuant to Sections 117 (g) and 303(d) of the Clean Water Act (CWA).

Why was a TMDL developed for the Chesapeake Bay? The Chesapeake Bay is a national treasure constituting the largest estuary in the United States and one of the largest and most biologically productive estuaries in the world. Despite significant efforts by federal, state, and local governments and other interested parties, water pollution in the Chesapeake Bay prevents the attainment of existing state water quality standards. The pollutants that are largely responsible for impairment of the Chesapeake Bay are nitrogen, phosphorus, and sediment. EPA, in coordination with the Bay watershed jurisdictions of Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia, and West Virginia, established nitrogen, phosphorus and sediment pollution budget for the Bay consistent with CWA requirements to guide and assist Chesapeake Bay restoration efforts.

Who developed the Bay TMDL? EPA Region III Water Protection Division was primarily responsible for the establishment of the Bay TMDL, at the request of the Bay jurisdictions. The Chesapeake Bay Program Office in EPA Region III had the modeling and water quality expertise needed to develop a TMDL. EPA Region II provided guidance and technical support to Region III and cosigned the final TMDL as New York State is included in the Chesapeake Bay watershed, and sources in New York State (like the other jurisdictions) contribute nitrogen, phosphorus and sediment to the Bay. EPA used the Chesapeake Bay Program committee structure to engage the watershed jurisdictions in the development of the TMDL, including the Chesapeake Bay Water Quality Goal Implementation Team (formerly the Water Quality Steering Committee and Nutrient Subcommittee), which is composed of the seven Bay watershed jurisdictions, the Chesapeake Bay Commission, the Susquehanna River Basin Commission, the Interstate Commission on the Potomac River Basin, and EPA Regions II and III. Major policy input was provided by the Chesapeake Bay Program Principals' Staff Committee (Secretaries from each Bay jurisdiction, the Chesapeake Bay Commission Executive Director, and the EPA Region III Regional Administrator) and Executive Council (Bay watershed State Governors, Mayor of District of Columbia, the Chesapeake Bay Commission Chair, and the EPA Administrator).

What is the scope of the Bay TMDL? The Bay TMDL addresses all segments of the Chesapeake Bay and its tidal tributaries. The Bay TMDL consists of pollutant allocations, addressing nitrogen, phosphorus and sediment, for each of the 92 segments in the Bay and tidal tributaries. EPA intends that the Bay TMDL will be established at a level necessary to ensure attainment of water quality standards in each of these segments. In addition, the Bay TMDL assigns individual and (as appropriate) aggregate maximum daily and annual allowable point source and nonpoint source loadings, called wasteload allocations (WLAs) and load allocations (LAs), respectively, across all jurisdictions within the Bay watershed.

How will the TMDL promote nitrogen, phosphorus and sediment reductions? Under CWA, the Bay TMDL established a watershed pollution budget for nitrogen, phosphorus and sedimentnecessary to meet water quality standards in the Bay. Other provisions of the CWA, as well as the jurisdictions' Watershed Implementation Plans (WIPs), were developed to implement the Bay TMDL. EPA worked with its partners, the Bay jurisdictions, to assist in their development of individual jurisdiction-specific WIPs, which collectively serve as part of the overall TMDL implementation framework. Those WIPs are not part of the Bay TMDL itself but are part of the TMDL record and help provide reasonable assurance that the necessary nitrogen, phosphorus and sediment reductions identified in the TMDL will be achieved. The WIPs identify specific nitrogen, phosphorus and sediment reduction targets by geographic location and sector to achieve allowable loadings, as well as a description and schedule of actions that the jurisdictions will take to achieve these reductions.

In accordance with Executive Order 13508, EPA and the jurisdictions also will provide the next set of two-year milestone commitments specifying what source controls will be taken to reduce nitrogen, phosphorus and sediment during that period. Any questions or comments regarding the substance of the individual WIPs, or the WIPs themselves should be addressed to the individual jurisdiction. Links to the WIPs are available at

Dated: December 29, 2010.
Jon M. Capacasa,
Water Protection Division, U.S. Environmental Protection Agency, Region III.
[FR Doc. 2010-33280 Filed 1-4-11; 8:45 am]
Comments Not Accepted
ID: EPA-R03-OW-2010-0736-0776
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Date Posted: Jan 5, 2011
Federal Register Number: 2010-33280
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