Gateway/Metropolitan St. Louis Sewer District (MSD)
Metropolitan St. Louis Sewer District (MSD)
The public utility that runs wastewater and stormwater sewers for St. Louis City and most of St. Louis County, and why it matters after a sewer backup.
| Type | Public wastewater and stormwater utility |
|---|---|
| Created | Approved by voters in 1954 |
| Serves | The City of St. Louis and most of St. Louis County, about 524 square miles |
| Program | Project Clear (Clean Water Act consent decree, 2012) |
What MSD is
The Metropolitan St. Louis Sewer District (MSD) is the public utility that collects and treats wastewater and manages stormwater for the City of St. Louis and most of St. Louis County, an area of about 524 square miles with roughly 1.3 million residents. Voters approved the district in 1954, and it began operating in 1956. Metro East communities in Illinois are served by their own municipal or private systems, not MSD.
Combined and separate sewers
Much of the City of St. Louis and the older inner-ring suburbs are served by combined sewers, which carry sewage and stormwater in the same pipe. Newer areas mostly have separate sanitary and storm sewers. During heavy rain, combined sewers and overloaded sanitary sewers can back up, and that pressure can push sewage up through basement floor drains, toilets and showers at the lowest level of a house.
Project Clear
In 2012 MSD entered a consent decree with the U.S. Environmental Protection Agency, the State of Missouri and the Missouri Coalition for the Environment under the Clean Water Act. The work done to meet it, called Project Clear, is a long-term, multibillion-dollar program of storage tunnels, sewer rehabilitation, green infrastructure and downspout disconnections intended to reduce sewer overflows and basement backups.
What this means after a backup
Water that backs up from a sewer is Category 3 (grossly contaminated) water under the IICRC S500 standard. Porous materials it touches, such as carpet, pad and the bottom of drywall, are usually removed rather than dried, and the area is cleaned and disinfected. Most homeowners policies exclude sewer and drain backup unless the policy has a sewer or water backup endorsement, so check your declarations page.
The pipe from your house to the public main (the lateral) is generally the property owner’s responsibility. If backups keep happening in dry weather, a plumber’s camera inspection of the lateral is the place to start. If they happen during heavy rain, report them to MSD.
Key takeaways
- MSD runs the public sewers for St. Louis City and most of St. Louis County; Illinois towns are served separately.
- Sewer backup water is Category 3 and needs removal and disinfection, not just drying.
- Backup coverage usually requires a separate endorsement.
Related glossary terms
- Category 3 water (black water)
- Sewer or water backup endorsement
- Sudden and accidental vs. gradual damage
Related services and guides
- Sewage cleanup
- Basement flooding cleanup
- Basement and storm water guide
- Insurance claims assistance
- Basement water in Greater St. Louis: flood, sewer backup or sump failure (PDF white paper)
Identifiers
References
- MSD Project Clear
- EPA: MSD consent decree (case 4:07-CV-1120)
- St. Louis Public Radio: MSD launches Project Clear
Reviewed by Jake Lusby, owner of Gateway Water & Mold. Part of our entity reference pages. See our editorial policy to report an error.
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