Water Cleanup Plan Studies for Toxics

Water Cleanup Plans, also called Total Maximum Daily Load evaluations for toxic chemicals or toxics TMDLs, determine how much of a chemical that a water body can receive each day, while still meeting water quality standards. These evaluations form the basis of Water Quality Improvement Projects for these water bodies.

Toxics TMDLs are conducted statewide. Many of the studies have been for legacy chemicals, those no longer in use.

Water Cleanup Plans - TMDL on the Department of Ecology publications pages links to all TMDL reports since 1986.

Select toxics TMDL reports are linked below.

Yakima River Pesticides and PCBs Total Maximum Daily Load: Volume 1. Water Quality Study Findings reports assessments from 2006 - 2008.

A Total Maximum Daily Load Evaluation for Chlorinated Pesticides and PCBs in the Walla Walla River

DDT Contamination and Transport in the Lower Mission Creek Basin, Chelan County: Total Maximum Daily Load Assessment

Lake Chelan DDT and PCBs in Fish Total Maximum Daily Load Study

TMDL Technical Assessment of DDT and PCBs in the Lower Okanogan River Basin

A Total Maximum Daily Load Evaluation for Arsenic in the Similkameen River

Palouse River Chlorinated Pesticide and PCB Total Maximum Daily Load: Water Quality Improvement Report and Implementation Plan


Related Information


Water Quality Assessment (303[d]) & Water Quality Improvement Projects (TMDLs) is a page from Ecology’s Water Quality Program that describes the TMDL process and links to other resources.