Guidance for meeting dissolved oxygen or oxygen demand TMDL MS4 permit requirements
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Guidance for meeting dissolved oxygen or oxygen demand TMDL MS4 permit requirements

What is a compliance schedule?
	A compliance schedule is a a schedule of compliance leading to compliance with Clean Water Act regulations. Compliance schedules must meet the following. it must be an enforceable sequence of actions or operations leading to compliance with a water quality-based effluent limitation; it must include an enforceable final effluent limitation and a date for its achievement that is within the timeframe allowed by the applicable State or federal law; if the date extends past the expiration date of a permit must include the final effluent limitations in the permit; the permitting authority has to make a reasonable finding, adequately supported by the administrative record, that the compliance schedule “will lead to compliance with an effluent limitation . . . ” “to meet water quality standards” by the end of the compliance schedule; the permitting authority has to make a reasonable finding that compliance with the final WQBEL is required “as soon as possible.”; the permitting authority has to make a reasonable finding, adequately supported by the administrative record, that the discharger cannot immediately comply with the WQBEL upon the effective date of the permit; Link to EPA guidance on compliance schedules;

This page provides information and guidance for MS4 (Municipal Separate Storm Sewer System) permittees who have total maximum daily load (TMDLs) wasteload allocations (WLAs) for dissolved oxygen or oxygen demand.

Overview

Https://stormwater.pca.state.mn.us/index.php?title=Oxygen demand

Total Maximum Daily Loads (TMDLs) with BOD or COD wasteload allocations

Currently there are three approved total maximum daily load (TMDLs) - for Hardwood Creek (Waterbody ID: 07010206-596), Trott Brook (Waterbody ID: 07010207-680), and Buffalo Creek (Waterbody ID: 07010205-638 (formerly 07010205-501)) - that include MS4 (Municipal Separate Storm Sewer System) wasteload allocations (WLAs) for oxygen demand that are not assigned a zero percent reduction. Hardwood Creek is impaired for aquatic life (fish) due to low dissolved oxygen and Trott Brook and Buffalo Creek are impaired for aquatic life (fish and aquatic macroinvertebrates) due to low dissolved oxygen.

MS4s with applicable dissolved oxygen/oxygen demand WLAs
Link to this table

TMDL Project	MS4 with a WLA for oxygen demand
Hardwood Creek Impaired Biota and Dissolved Oxygen TMDL	Anoka County
	Hugo City
	Lino Lakes City
	MNDOT Metro District
	Rice Creek Watershed District
	Washington County
Trott Brook (Rum River Watershed TMDL)	Elk River City
	Nowthen City
	Ramsey City
	Saint Francis City
	Sherburne County
Buffalo Creek (South Fork Crow River Watershed TMDL)	Glencoe City

MS4 permit requirement (Permit/Application Section 22.2)

Sections 22.2 and 12.8 of the MS4 permit provides the requirements for permittees who have a TMDL WLA for dissolved oxygen or oxygen demand.

Section 22.2: If the permittee has an applicable WLA for dissolved oxygen or oxygen demand, nitrate, TSS, and TP, the permittee must provide a summary of the permittee's progress toward achieving applicable WLAs for dissolved oxygen or oxygen demand, nitrate, TSS, and TP with the annual report required in item 25.3. The summary must include the following information:
a. a list of all BMPs applied towards achieving applicable WLAs for dissolved oxygen or oxygen demand, nitrate, TSS, and TP;
b. the implementation status of BMPs included in the compliance schedule at the time of final application submittal.

Section 12.8: The applicant must submit a compliance schedule for each applicable Waste Load Allocation (WLA) not being met for dissolved oxygen or oxygen demand, nitrate, total suspended solids (TSS), and total phosphorus (TP). The applicant may develop a compliance schedule to include multiple WLAs. The applicant's compliance schedule must include the following information:
a. proposed BMPs or progress toward implementation of BMPs to be achieved during the permit term;
b. the year each BMP is expected to be implemented;
c. a target year the applicable WLA(s) will be achieved

Street sweeping is an effective BMP for removing organic material. Image courtesy Sarah Hobbie, University of Minnesota

Photo illustrating permeable interlocking concrete pavement. Permeable pavements are an infiltration BMP that is effective for dissolved oxygen and oxygen demand impairments.

The Minnesota Pollution Control Agency (MPCA) recommends including BMPs/activities in your MS4’s compliance schedule that reduce organic matter and carbon (e.g. leaf litter), since these BMPs/activities will also reduce oxygen-demanding substances in the streams (see table below). Most BMPs that reduce organic matter (e.g. street sweeping), will also reduce phosphorus, sediment and/or bacteria (Escherichia (E.) coli, fecal coliform) loading to waterbodies. Additionally, if BMPs/activities are implemented across the entire jurisdictional area of your MS4, some activities may be used to demonstrate progress towards additional applicable phosphorus, total suspended solids (TSS), and/or bacteria (E. coli, fecal coliform) WLAs.

Potential sources of organic matter and carbon and BMPs/Activities that could be included in your compliance schedule to address dissolved oxygen/oxygen demand applicable WLAs
Link to this table

General Category	Source	BMP/Activity
MS4 Infrastructure	Decaying plant matter, litter, and sediment in the storm drain system	Enhance street sweeping program
		Remove leaf litter and soil in street and gutters (e.g. implement an Adopt-a-storm drain program). Educate property owners on proper yard waste management
	Stormwater runoff from impervious surfaces	Implement source, rate, volume controls (i.e. adopt minimal impact design standards (MIDS) for new, redevelopment, and linear projects)
		Minimize impervious surfaces
		Implement filtration practices, infiltration practices, and sedimentation practices
Domestic pets	Dogs, cats, dog parks, walking trails, residential yard and sidewalk runoff (spring runoff after winter accumulation)	Install pet waste disposal stations along trails, in dog parks, etc
		Pass and enforce pet waste ordinances and educate pet owners about them
		Add infiltration BMPs downstream of parks/residential areas and upstream of stormwater pipes (i.e., somewhere between the park/residential area and the stormwater outfall to intercept and infiltrate some or all of the flow from these areas)
Residential sources	See this section
Industrial and commercial practices	See this section

Additional information

Additional information on potential BMPs/activities to address the Hardwood Creek, Trott Brook Creek, and Buffalo Creek dissolved oxygen impairments may also be available in the following:

Contents

Overview

Total Maximum Daily Loads (TMDLs) with BOD or COD wasteload allocations

MS4 permit requirement (Permit/Application Section 22.2)

Additional information

Hardwood Creek TMDL

Rum River Watershed TMDL

South Fork Crow River Watershed TMDL

Related Pages