Mercury Total Maximum Daily Load (TMDL) Implementation Plan

Project Status:     Complete

Project Type:        Stormwater         

Staff Contact:       Bryan Burnham, Public Works Director,

503-852-7575, bburnham@ci.carlton.or.us

In April 2017, the U.S. District Court issued a ruling requiring the U.S. Environmental Protection Agency (EPA) to revise the 2006 mercury TMDL by November 2019. EPA, with input from the Oregon Department of Environmental Quality (DEQ), led the technical work associated with modeling the amount of mercury gained and lost by stream systems, as well as the concentration of mercury in the aquatic food web. DEQ led the development of a water quality management plan (WQMP) to describe the overall framework for implementing the TMDL. The WQMP describes activities, programs, legal authorities and other measures for which DEQ and other designated management agencies (DMAs) have regulatory responsibility. A DMA is “a federal, state or local governmental agency that has legal authority of a sector or source contributing pollutants and is identified as such by the DEQ in a TMDL.”

The DEQ has named Carlton as a DMA in the Yamhill Subbasin because the City has legal authority within its city limits, and because the City’s stormwater drains to a tributary of the Yamhill River. The tributary flows into the Yamhill River at river mile 9. Under the TMDL, the City of Carlton must develop a non-point source TMDL implementation plan to address mercury in the drainage basins, including the Yamhill River and Hawn Creek. This memorandum represents the required Yamhill Subbasin TMDL implementation plan for the City of Carlton.

This plan is due to DEQ by September 2, 2022. Following DEQ plan approval, the City Council will formally adopt the plan within 60 days.  DEQ has requested that plans be submitted to them in the fall of 2021 to allow for plenty of review time.

This project is now completed, ongoing maintenance and updates can be found here: https://www.ci.carlton.or.us/publicworks/page/carlton-mercury-tmdl-implementation-plan