Ensuring That TMDLs are Implemented

Reasonable Assurance

When establishing a TMDL, States allocate reductions of a particular pollutant among the pollutant sources in the waterbody. These sources may include both point sources and nonpoint sources. In allocating reductions to nonpoint sources, States must provide reasonable assurance that those nonpoint sources will meet their allocated amount of reductions. There are a variety of ways in which a State can provide reasonable assurance such as, through the implementation of pollution control measures, developing and implementing nonpoint source control plans and if available, other State regulations and policies governing such facilities.

Satisfying Reasonable Assurance Through the Issuance of an NPDES Permit

States may not be able to provide reasonable assurance that certain nonpoint sources will meet their allocated amount of reductions. In these instances, States authorized to administer the NPDES program may designate these sources as point sources and require that they obtain an NPDES permit. Reasonable assurance is satisfied by designating these sources as point sources and issuing them an NPDES permit.

A State may choose not to designate these sources as point sources. By not designating these sources, EPA may find that the State failed to provide reasonable assurance. Because reasonable assurance is a required element of a TMDL, EPA may then disapprove that State's TMDL. If EPA disapproves a TMDL, EPA must establish the TMDL.

How Can We Ensure That TMDLs, Once Established, Will Be Implemented?

Proposed revisions to the NPDES regulations:

Designation Authority for Animal Feeding Operations and Aquatic Animal Production Facilities

Authority to designate Animal Feeding Operations (AFOs) and Aquatic Animal Production Facilities (AAPFs) currently lies with the NPDES permitting authority. The permitting authority may be the State (where that State is authorized to administer the NPDES program) or the EPA Regional Administrator (in States that do not have the authority to administer the NPDES program) as the context requires.

EPA is proposing to allow the Regional Administrator to designate these sources even when it is not the permitting authority. This authority will be limited to instances where it is necessary to provide reasonable assurance that these sources will meet their allocated amount of reductions when EPA establishes a TMDL. The Agency believes that this authority is necessary because reasonable assurance is a required element of a TMDL.

Designation Authority for Discharges From Silviculture Operations

EPA is proposing to allow both States and the Regional Administrator to designate certain discharges from silviculture activities. EPA's authority to designate these sources will be limited to instances where it is necessary to provide reasonable assurance that these sources will meet their allocated amount of reductions when EPA establishes a TMDL. The Agency believes that this authority is necessary because reasonable assurance is a required element of a TMDL

Reissuing Expired Permits in Impaired Waterbodies

States with approved NPDES programs issue permits to point sources within their jurisdiction. When these permits expire, the State typically issues the permittee a new permit. In some instances, these permits expire and the permittee operates under an expired permit. Some of these expired permits are inconsistent with applicable TMDLs. Authorizing discharges under these permits frustrates the goals of the Clean Water Act by delaying the implementation of TMDLs. In these instances and when the State fails to act, EPA is proposing to allow the Regional Administrator to reissue these permits consistent with the applicable TMDL.