Metropolitan St. Louis Sewer District

The purpose of the St. Louis County Phase II Stormwater Management Plan is to improve area water quality by preventing harmful pollutants from being carried by storm water runoff into local water bodies. MSD partners with 58 municipalities (co-permittees) to comply with storm water permit requirements for the St. Louis Metropolitan Small Municipal Separate Storm Sewer System (MS4).

Best management practices (BMPs) are methods to prevent or reduce the pollutants in storm water runoff. Our St. Louis County Phase II Storm Water Management Plan (SWMP) includes BMPs that address potential sources of pollutants in storm water as required by the federal and state regulations. The implementation of BMPs in the SWMP will satisfy the six minimum control measures (MCMs) required by the Phase II Regulations.

These six minimum control measures are:

I. Public Education and Outreach

The Plan implements a public education program to distribute educational materials to the community and conduct outreach activities about the impacts of storm water discharges on water bodies and the steps that the public can take to reduce pollutants in storm water runoff.

II. Public Involvement and Participation

The public is actively involved in implementation of the storm water management program through community groups of all kinds and participation in activities to reduce storm water pollution.

III. Illicit Discharge Detection and Elimination

MSD has developed and implemented a program to detect and eliminate illicit discharges into our MS4 and area streams. We developed and maintain a map of the area streams, storm sewers and storm sewer outfalls.

IV. Construction Site Storm Water Runoff Control

Land disturbance programs must be implemented to reduce pollutants in storm water runoff from construction activities that disturb the land. The BMPs required by the program focus primarily on erosion and sediment control.

V. Post-Construction Storm Water Management

A program to address storm water runoff from new development and redevelopment projects must be implemented to reduce pollutants in storm water runoff from developed property. The program must ensure that BMPs are in place to prevent or minimize water quality impacts. Structural BMPs include storm water detention ponds, infiltration basins, filter strips and more.

VI. Pollution Prevention/Good Housekeeping for Municipal Operations

An operation and maintenance program that has the ultimate goal of preventing or reducing pollutant runoff from municipal operations will be implemented by all co-permittees.