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1、.Total Maximum Daily Load ProgramNEW!TMDL regulations proposed during the Clinton Administration are being withdrawn by the US Environmental Protection Agency according to a notice in the December 27 Federal Register. The notice in the Federal Register states that EPA is withdrawing its proposal, wh
2、ich had been scheduled to take effect April 30, because of its belief that significant changes would have been necessary before the rule "could serve as the blueprint for an efficient and effective TMDL program. Further, the notice states, EPA needs additional time to decide "whether and h
3、ow to revise the currently-effective regulations implementing the TMDL program in a way that will best achieve the goals of the Clean Water Act." The notice also credits states with making "considerable progress" over the past three years in developing TMDLs, as a result of greater ou
4、treach and cooperation. Currently some 7,000 TMDLs have been established by the states. Comments on the proposed withdrawal of the rule must be submitted to the EPA by January 27.BackgroundTotal Maximum Daily Loads (TMDLs), a requirement of the Clean Water Act Section 303(d), are a tool for implemen
5、ting State water quality standards. They are based on the relationship between pollution sources and in-stream water quality conditions. A TMDL establishes the maximum amount of an impairing substance or stressor that a waterbody can assimilate and still meet Water Quality Standards (WQSs) and alloc
6、ates that load among pollution contributors. A TMDL, that addresses a single pollutant or stressor for each waterbody, is the sum of the allowed pollutant loads for point sources, non-point sources, projected growth and a margin of safety, as follows:TMDL = Point Sources + Nonpoint Sources + Project
7、ed Growth + Margin of SafetyLoad allocations are determined through the review of monitoring data and watershed modeling. Waterbodies require TMDLs when the following pollution control requirements are not stringent enough to meet applicable WQSs:· Technology-based effluent limitations required
8、 by the CWA;· More stringent effluent limitations required by either state or local authority; and· Other pollution control requirements (e.g., best management practices) required by local, state, or federal authority are not stringent enough to implement any WQS applicable to such waters.
9、Program and Policy GoalsThe CWA requires that Maryland:1. Establish WQSs for its waters.2. Monitor the conditions of its waters. 3. List waterbodies that do not meet WQSs with technology-based controls alone (303(d) list). 4. Set priority rankings for the waterbodies listed.5. Establish TMDLs
10、that meet WQSs for each listed waterbody.6. Solicit public comment. 7. Submit 303(d) list and TMDLs to US EPA for approval. 8. Incorporate TMDLs into the State's Continuing Planning Process.Maryland's current 303(d) list (i.e., waterbodies that may require TMDLs), identifies 130 impaired wat
11、erbodies. Various combinations of waterbodies and pollutants result in over 350 potential TMDLs statewide.Many of Marylands existing efforts to protect and restore water quality will help the State meet its TMDL goals. In particular, the waters identified for TMDLs are also at the core of Marylands
12、Clean Water Action Plan (see the Clean Water Action Plan section of this website). In many ways, Marylands ongoing effort to reduce nutrients entering the Chesapeake Bay has been very similar to a TMDL process. Stakeholders and researchers recognized water quality problems, set an achievable goal, a
13、nd then identified specific controls for point and nonpoint pollution sources intended to achieve the goal. This is the essence of a TMDL.A TMDL represents an upper limit, or "cap”, on pollutant loads to a waterbody, and, as a result there must be mechanisms to ensure that the cap is not exceed
14、ed. These mechanisms include state and local permitting and regulatory authority, and voluntary efforts under the Chesapeake Bay Agreement that are supported by technical and financial assistance. Maryland has one of the most comprehensive, multi-level, community-based estuary restoration programs in the country. For Additional InformationClean Water ActMDE TMDL Program Website US EPAs TMDL WebsiteMDE TMDL contacts:Melissa Chatham, (410) 537-3937Elaine Dietz, (410) 537-3667*;