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===Total Maximum Daily Loads (TMDLs)===
 
===Total Maximum Daily Loads (TMDLs)===
Currently there are two approved TMDLs for Brown’s Creek and Miller Creek that include <span title="A municipal separate storm sewer system (MS4) is a means of transportation, individually or in a system, (e.g. roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, storm drains, etc.) that are: owned or operated by a public entity (e.g. cities, townships, counties, military bases, hospitals, prison complexes, highway departments, universities, etc.) with jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes. This includes special districts under State law (sewer, flood control, or drainage districts, etc.), an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act; designed or used for collecting or transporting stormwater; not a combined sewer; and not part of a publicly owned treatment works."> '''MS4'''</span> (Municipal Separate Storm Sewer System)<span title="the portion of a receiving water's assimilative capacity that is allocated to one of its existing or future point sources of pollution"> '''wasteload allocations'''</span> (WLAs) for thermal loading. Brown’s Creek is impaired for aquatic life due to a lack of cold water fish assemblage. Miller Creek is impaired for aquatic life due to a lack of cold water fish assemblage and elevated water temperature.
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Currently there are two approved <span title="the amount of a pollutant from both point and nonpoint sources that a waterbody can receive and still meet water quality standards"> [https://stormwater.pca.state.mn.us/index.php?title=Total_Maximum_Daily_Loads_(TMDLs) '''total maximum daily load''']</span> (TMDLs) for Brown’s Creek and Miller Creek that include <span title="A municipal separate storm sewer system (MS4) is a means of transportation, individually or in a system, (e.g. roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, storm drains, etc.) that are: owned or operated by a public entity (e.g. cities, townships, counties, military bases, hospitals, prison complexes, highway departments, universities, etc.) with jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes. This includes special districts under State law (sewer, flood control, or drainage districts, etc.), an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act; designed or used for collecting or transporting stormwater; not a combined sewer; and not part of a publicly owned treatment works."> '''MS4'''</span> (Municipal Separate Storm Sewer System)<span title="the portion of a receiving water's assimilative capacity that is allocated to one of its existing or future point sources of pollution"> '''wasteload allocations'''</span> (WLAs) for thermal loading. Brown’s Creek is impaired for aquatic life due to a lack of cold water fish assemblage. Miller Creek is impaired for aquatic life due to a lack of cold water fish assemblage and elevated water temperature.
  
 
===Requirement (Permit Section 22.7)===
 
===Requirement (Permit Section 22.7)===

Revision as of 16:46, 18 October 2019

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DRAFT Temperature TMDL WLA Guidance (MS4 General Permit Section 22)

Total Maximum Daily Loads (TMDLs)

Currently there are two approved total maximum daily load (TMDLs) for Brown’s Creek and Miller Creek that include MS4 (Municipal Separate Storm Sewer System) wasteload allocations (WLAs) for thermal loading. Brown’s Creek is impaired for aquatic life due to a lack of cold water fish assemblage. Miller Creek is impaired for aquatic life due to a lack of cold water fish assemblage and elevated water temperature.

Requirement (Permit Section 22.7)

If the permittee has an applicable WLA for temperature that includes a reduction greater than zero percent, the permittee must maintain a written plan that identifies specific activities the permittee will implement to reduce thermal loading during the permit term (Table 1). The written plan may include, but is not limited to:

  • a. implementation of infiltration BMPs such as bioinfiltration practices;
  • b. disconnection and/or reduction of impervious surfaces;
  • c. retrofitting existing structural stormwater BMPs; and
  • d. improvement of riparian vegetation.

MS4s with applicable temperature WLAs
Link to this table

TMDL Project MS4 with a WLA for temperature
Browns Creek TMDL Stillwater City
Miller Creek TMDL Duluth City
Hermantown City
Rice Lake City
MnDOT Outstate
St. Louis County
University of Minnesota-Duluth
Lake Superior College

Information on potential BMPs/activities that may be included in the written plan to reduce heat to Brown’s Creek and Miller Creek are available in the following:

Brown’s Creek TMDL

Miller Creek TMDL