Water Quality

In December 2018, the U.S. Environmental Protection Agency approved Oregon's 2012 Clean Water Act Section 303(d) list of impaired waterbodies that need pollution reduction plans, called Total Maximum Daily Loads or TMDLs. DEQ uses the 303(d) list to determine requirements for water quality permits and total maximum daily loads.
EPA added 285 water bodies to the list, removed 56 water bodies from the list, and reclassified 714 stream segments affected by ongoing litigation over temperature water quality standards.
Find documents detailing EPA's review, changes, and final approval of Oregon's 2012 303(d) list at EPA's Impaired Waters and TMDL webpage.


In November 2014, DEQ submitted a draft 2012 Integrated Report and 303(d) List of water quality limited waters in the Umatilla and Willamette basins. In December 2016, EPA approved most of the submitted 303(d) listings and delistings and proposed additional water bodies for Oregon’s 303(d) list. 


2012 Integrated Report submittal

Oregon’s 2012 Integrated Report Assessment Database and 303(d) List is a searchable database report with data for each water body, pollutant and location that DEQ has assessed, and the conclusion about water quality in each water body.