Region 1: EPA New England
The Components of TMDL Plans
- Descriptions of the waterbody, pollutant(s) of concern, point and nonpoint pollutant sources, and the priority ranking of the waterbody.
- Description of the applicable water quality standards and numeric water-quality target.
- Assessment of the waterbody's loading capacity for the applicable pollutant(s). This includes a description of methods used to establish a relationship between the water-quality target and the pollutant sources, and commonly includes a description of critical environmental conditions.
- Establishment of "load allocations" (LAs), which identify the portion of the loading capacity allocated to nonpoint sources, including atmospheric deposition and natural background.
- Establishment of "wasteload allocations" (WLAs), which identify the portion of the loading capacity allocated to point sources
- Description of a margin of safety (MOS) to account for uncertainties in the loading analysis.
- Assessment of seasonal variation (climate and streamflow) on the ability of waterbody to meet WQSs.
- EPA encourages states to develop monitoring plans for TMDLs to assess progress in meeting TMDL goals.
- EPA encourages states to develop TMDL implementation plans, which include reasonable assurances that nonpoint source loading reductions will be achieved.
- Each state must provide for public participation consistent with state requirements.