TMDL Programs

Restoring Impaired Waters

When a water body is assessed to be impaired for one or more reasons, Total Maximum Daily Loads (TMDLs) are developed by state agencies to determine the total amount of a pollutant that a body of water can handle without resulting in an impaired status. TMDLs are typically implemented through National Pollutant Discharge Elimination System (NPDES) permits. Point source discharges must be controlled through the use of water quality-based effluent limits in permits issued to point source dischargers. Non-point source load reduction actions are implemented through a wide variety of programs at the state, local and federal level. These programs may be regulatory, non-regulatory or incentive-based. Each state develops TMDLs for water bodies that they include on their list of impaired waters and then submits them to EPA for approval. EPA reviews and either approves or disapproves the TMDL. If EPA disapproves the TMDL, EPA must develop a replacement TMDL.

TMDL Experience Case Study

The Delaware River Basin Commission (DRBC), along with the states of New Jersey, Pennsylvania, Delaware, and the U.S. Environmental Protection Agency (EPA) initiated a cooperative effort to evaluate and control polychlorinated biphenyls (PCBs) in the Delaware Estuary. Point source discharges of PCBs were one of several source categories being evaluated as part of the TMDL program. More than 100 dischargers were required to undertake sampling for PCBs using ultra trace, congener-specific laboratory methods.

Eurofins Environment Testing worked with the US Geological Survey, performing 1668A analysis, to determine inputs to the estuary from the tributaries. In Phase 1 of the TMDL study, Eurofins Environment Testing participated in the development of the QAPP for the DRBC Coalition of Municipal and Industrial Dischargers. In Phase 2 of the study, Eurofins Environment Testing participated in round-table discussions with the DRBC Data Quality Objective Technical Advisory Committee. This planning enabled the DRBC to establish the quality assurance criteria for the study.

Under the final rule, 60 point source dischargers were required to develop and implement Pollutant Minimization Plans (PMPs) and to monitor their PCB discharges. Eurofins Environment Testing assisted several dischargers with the development of their plans and provided the analytical programs to support them.

Eurofins Environment Testing also supports PCB TMDL programs for the Virginia Department of Environmental Quality (DEQ) and the San Francisco Bay.