The City of St. Louis’ Land Reutilization Authority (LRA) and The Metropolitan St. Louis Sewer District (MSD) have finalized an agreement for a $3 million pilot green infrastructure program in the combined sewer portion of MSD’s service area. This pilot program is meant to help understand the regulatory, logistical, financial, and educational challenges that will need to be managed as green infrastructure is utilized to address sewer overflows. If successful, similar type programs may be implemented throughout the St. Louis area.
Designed to reduce the amount of sewer overflow volumes that occur during moderate to heavy rainfalls, thereby protecting local waterways, this program will also assist redevelopment of vacant properties through the construction of stormwater facilities that meet MSD’s current stormwater management requirements.
Combined sewers handle both wastewater and stormwater through the same sewer pipe and have a limited capacity. During moderate to heavy rainfalls, these sewers, which serve both the City of St. Louis and large portions of St. Louis County, can become overwhelmed by too much rainwater entering the sewer system. The result of this “overcharging” is that sewer overflow points throughout the City and County activate and act as relief valves. Without these overflow points, potentially hundreds to thousands of basement backups could occur and miles of streets could flood. Green infrastructure, such as the types that will be utilized in the LRA-MSD pilot program, can lower the costs of addressing these overflows, improve overall water quality, and add to the aesthetic value and quality of life in residential areas throughout the St. Louis area.
Specific to the LRA-MSD pilot program, beginning in September 2010, approximately 50% of the $3 million will be used to remove vacant structures from approximately 200 LRA owned lots in North St. Louis City. LRA will manage administration of these funds and the demolition process itself. As structures are removed, MSD will utilize the remainder of the funds to build green infrastructure facilities on these properties that reduce stormwater flows into area sewers. These facilities will include rain gardens, pervious pavements, detention and micro-detention basins, planter boxes, rain barrels, wetlands, and other types of green infrastructure that hold back or divert storm runoff during rainstorms. The $3 million for this work is funded by MSD’s sanitary sewer rates. Demolition is expected to be completed over the next several months and construction of the green facilities will take place throughout 2011.