Difference between revisions of "Overview of TMDLs"
m |
|||
| Line 3: | Line 3: | ||
==Definition of a TMDL== | ==Definition of a TMDL== | ||
==Overview of Wasteload Allocations (WLAs)== | ==Overview of Wasteload Allocations (WLAs)== | ||
| + | When assessing which pollutant loads should be placed into the WLA, it is necessary to clearly define what is covered under an NPDES permit. Minnesota’s Phase 2 [[http://stormwater.pca.state.mn.us/index.php/MS4_General_Permit|Municipal General Permit]] states that only the portions of the storm sewer system that are under a permittee's operational control are authorized by the permit. MPCA interprets this to mean an MS4 is responsible for ensuring its discharge is in compliance with water quality based effluent limits (WQBELs), since the discharge is within the publicly owned or operated conveyance system. The permittee must take appropriate measures to bring its MS4 into compliance. All discharges originating within a regulated MS4 or to a regulated MS4 from property owned or operated by the regulated MS4 are put into the WLA. Other discharges to an MS4 are also put into the WLA when the permittee has regulatory authority to control the discharges. | ||
| + | |||
| + | The Wasteload Allocation (WLA) is the portion of a receiving water's loading capacity that is allocated to one of its existing or future point sources of pollution. WLAs constitute a type of water quality-based effluent limitation ([http://www.gpo.gov/fdsys/pkg/CFR-2002-title40-vol18/pdf/CFR-2002-title40-vol18-sec130-2.pdf 40 CFR 130.2]). NPDES-permitted stormwater discharges must be included in the WLA. | ||
Revision as of 13:45, 9 October 2013
Information for this page has not been developed. It is anticipated this page will be populated in summer of 2013
Definition of a TMDL
Overview of Wasteload Allocations (WLAs)
When assessing which pollutant loads should be placed into the WLA, it is necessary to clearly define what is covered under an NPDES permit. Minnesota’s Phase 2 [General Permit] states that only the portions of the storm sewer system that are under a permittee's operational control are authorized by the permit. MPCA interprets this to mean an MS4 is responsible for ensuring its discharge is in compliance with water quality based effluent limits (WQBELs), since the discharge is within the publicly owned or operated conveyance system. The permittee must take appropriate measures to bring its MS4 into compliance. All discharges originating within a regulated MS4 or to a regulated MS4 from property owned or operated by the regulated MS4 are put into the WLA. Other discharges to an MS4 are also put into the WLA when the permittee has regulatory authority to control the discharges.
The Wasteload Allocation (WLA) is the portion of a receiving water's loading capacity that is allocated to one of its existing or future point sources of pollution. WLAs constitute a type of water quality-based effluent limitation (40 CFR 130.2). NPDES-permitted stormwater discharges must be included in the WLA.