Total Maximum Daily Load

From Salish Sea Wiki


Wiki Rules


Link to List of Workgroups Link to List of Topics Link to List of Places

Link to List of Efforts Link to List of Products Link to List of Documents Link to List of Graphics Link to List of Websites

Link to Delta Sites Link to Embayment Sites Link to Beach Sites Link to Rocky Headland Sites

Link to Headwater Sites Link to Lowland Watershed Sites Link to Floodplain Sites

TMDL is a term defined under the Clean Water Act which describes a planning and implementation process for capping and reducing water quality indicators in streams. A TMDL is mandated after 303(d) listing of a stream for a violation of water quality standards. Washington State Department of Ecology has limited resources to conduct a TMDL, which requires an evidence-based evaluation of the factors causing the water quality standard violation.


Notes

  • Browse TMDLs by WRIAs - http://www.ecy.wa.gov/programs/wq/tmdl/TMDLsbyWria/TMDLbyWria.html
  • Because of the rigor of a TMDL, it becomes a body of "best available science" which can then be used to inform Growth Management Act and Shoreline Managment Act planning, which requires the use of best available science.
  • TMDL analysis provides a basis for action, but there is not consequence for not following up on a TMDL analysis. The NPDES permit process is where a local jurisdiction can face penalties for failing to work toward correcting a violation.
  • I have not found any evidence for how many TMDL/NPDES processes actually lead to de-listing of a water body. It seems like concerted action for solving water quality issues often require a mixture of different forces. (See Shellfish Protection District or Drayton Harbor for examples driven by shellfish production impacts).