Future updates

Timelines shown below are approximate. We update this page infrequently.

Information: Updated October 31, 2018

TMDLs

The work includes the following.

1. Develop and enhance guidance and resources for permittees to evaluate TMDL-related permit compliance. This would include developing guidance for more robust modeling tools and general monitoring guidance that permittees could use to assess:

• Baseline pollutant loading
• Current pollutant loading
• Cumulative estimated reductions

2. Develop outreach, training, and/or workshops to accompany these resources.

To view the workplan - File:Wiki work plan TMDLs.docx

Pretreatment

• Provide information on design criteria and design considerations, construction guidelines, and maintenance recommendations for pretreatment settling practices. This includes proprietary and non-proprietary practices, including forebays. Includes photos, schematics, details or CAD drawings, and other images as necessary or appropriate.
• Provide general information and design, construction, and maintenance guidance for level spreaders. Ensure the information is consistent with information on pretreatment filter strips and pretreatment settling practices.
• Provide 5 to 7 case studies summarizing the use of pretreatment practices, including at least one case study for each of the following practices.
• Vegetated filter strip
• Forebay
• Proprietary settling device
• Screen

See workplan - File:Wiki pretreatment workplan.docx

Construction stormwater

Update existing information and provide new information on active construction site erosion prevention and sediment control, including general and technical information on BMPs. Potential BMPs include the following.

• Temporary Sediment Traps and Basins
• Stabilized Earth/Soil Berm, including wood chip berm
• Buffer Zones
• Lined Channels
• Riprap
• Temporary stream crossing
• Dewatering (6.40), including
  • Chemical Treatment
  • Sediment Filtration

See workplan - File:Wiki Construction SW workplan.docx

Swales

Include case studies for the recently completed sections on dry swale, wet swale, and step pool.

See workplan - File:Wiki swale case studies workplan.docx

MS4 Accelerated Implementation – Stormwater Case Studies

Develop and disseminate information on case studies of water quality projects for Municipal Separate Storm Sewer System (MS4) permittees. The case studies cover a range of MS4 permit issues and types of MS4s (cities, townships, colleges, watershed districts/watershed management organizations).

See workplan - File:Wiki case study work plan.docx

Phosphorus export from constructed ponds

Studies show that constructed stormwater ponds can export phosphorus. We will execute a work order to compile existing information on phosphorus dynamics in ponds, conditions that result in phosphorus export, and recommended design, construction, and maintenance practices. NOTE this is an area where further research is needed, and the information obtained through this work order is likely to be limited by knowledge gaps on this topic.

See workplan - File:Wiki phosphorus export work plan.docx

Other topics of interest

We are pursuing opportunities to address the following topics, with the goal of developing guidance for the stormwater manual.

• Credits for street sweeping
• Improved information on suitable engineered media for bioretention practices
• Improved guidance for iron enhanced stormwater practices

On-going work being done by MPCA staff

Green infrastructure for stormwater management

We have created a portal page containing links to pages addressing Green Infrastructure. We continue to work on pages associated with this topic.

Road salt

We continue updating information on road salt as time allows.