NPDES STORM WATER PROGRAM & MS4
In 1987, the National Pollutant Discharge Elimination System (NPDES) was developed by the federal government and is being implemented through local and state government to address environmental problems created by uncontrolled storm water runoff from developing properties.
The City of Marshall is required by the U.S. Environmental Protection Agency (EPA) and Minnesota Pollution Control Agency (MPCA) to reduce pollution from storm water to surface waters and groundwater. The City is required to operate with a Minnesota NPDES MS4 permit and, therefore, the City of Marshall is a designated MS4. MS4’s designated by rule are cities and townships with a population of at least 10,000 and cities and townships with a population of 5,000 and discharging to valuable or polluted waters.
HOW ARE POLLUTANTS FROM STORM WATER DISCHARGES REDUCED?
The primary goal of the NPDES MS4 Permit is to restore and maintain chemical, physical, and biological integrity of waters of the state through management and treatment or urban storm water runoff. As part of the NPDES MS4 Permit, the City of Marshall was required to develop and implement a Storm Water Pollution Prevention Program (SWPPP).
The City of Marshall’s permit contains a SWPPP that includes six Minimum Control Measures (MCM’s):
- Public education and outreach
- Public participation/involvement
- Illicit discharge detection and elimination
- Construction site storm water runoff control
- Post-construction storm water management in new development and redevelopment
- Pollution prevention/good housekeeping
Best Management Practices (BMPs) that apply to each MCM are implemented to reduce the amount of sediment and pollutants that are discharged from our storm sewer system to the maximum extent practicable. The SWPPP includes additional BMPs to address the Lower Minnesota River Basin Total Maximum Daily Load (TMDL) Implementation Plan.
WHAT ACTIVITIES DOES THE CITY OF MARSHALL PERFORM RELATED TO MCMs 1-6?
MCM 1: Public Education and Outreach
- Develop and distribute educational materials
- Public Works Department Informational Handout
- City website
- Seasonal, storm water-related public notices in newspaper
- Discuss construction site storm water topics at annual contractor’s meeting and annual plumber’s meeting
- Distribute informational packet/brochure explaining construction site erosion control practices
- Marshall Municipal Utilities (MMU) distributes Storm Water Utility informational brochure
MCM 2: Public Involvement
- Host annual meeting at City Hall to review and discuss the Annual Report for the City’s SWPPP
- Publish notice in local newspaper for annual meeting
- Meet on site with contractors or homeowners to review project requirements
MCM 3: Illicit Discharge Detection and Elimination
- Develop and maintain storm sewer system map
- Prohibit and enforce against illicit connections and discharges to the MS4
- Conduct video inspections of sanitary and storm sewer systems yearly, as schedule allows
- Educate city staff and public on hazards associated with illicit discharges
MCM 4: Construction Site Storm Water Runoff Control
- Enforce surface water management ordinances
- Complete site plan reviews of project site erosion control measures
- Land Disturbance Permit required by city for all land disturbing activities of 2,000 square feet or larger
- Review site erosion control measures needed to meet city ordinance and MS4 Permit requirements
- Building permits issued only after Land Disturbance Permit is approved
- Complete construction site inspections monthly and after large rainfall events
- Ensure best practices are being followed to prevent erosion and illicit discharge to MS4
MCM 5: Post-Construction Storm Water Management in New Development and Redevelopment
- Ordinances in place to ensure current MS4 Permit requirements are being met
- Maintain and update records of new Best Management Practices (BMPs) annually
- Ensure that subdivision grading and drainage plans are maintained
- Routinely inspect storm water outfalls, ponds, and other management facilities and perform required maintenance to ensure functionality
MCM 6: Pollution Prevention/Good Housekeeping
- Regularly conduct street sweeping operations of city-owned streets and parking lots to pick up sediments, leaves, and other debris from these surfaces
- Reduce quantity of sediments and pollutants from reaching storm sewer system
- Routinely inspect storm water control infrastructure
- Catch basins, manholes, ponds, ditches, outfalls, etc.
- Inspect city materials stockpiles and storage/handling areas
- Clean and repair pipes, ponds, catch basins, ditches, etc.