Below is a transcript of a prepared statement read at Monday night's meeting of the La Grange village board of trustees by Public Works Director Ryan Gillingham, describing the village's sewer system and discussing steps being taken locally and regionally to address flooding issues.
The majority of the village's sewer system is a combined system, which means that the sanitary and storm water are combined into a single pipe. This was the prevalent design of sewer systems when the village was first developed over 100 years ago. During dry weather the sewage enters these combined sewers and flows to larger sewers managed by the Metropolitan Water Reclamation District MWRD. From there the sewage goes to treatment facilities such as the Stickney plant. These sewers have a finite capacity and, unfortunately, during wet-weather conditions when capacity is exceeded, the potential exists for street flooding and basement backups to occur. In order to add additional capacity within these combined systems on a regional basis, MWRD initiated a tunnel and reservoir plan, also known as the Deep Tunnel. During wet-weather conditions, a series of large-diameter tunnels, some as large as 35 feet in diameter, and a reservoir, receive the overflow sewage that exceeds the capacity of the regular sewer system. Once the capacity of the Deep Tunnel system is exceeded, events call for combined sewer overflows, which release sewage into area waterways. On a local level, when the sewers reach capacity, as I mentioned, street flooding and basement backups can occur. The village has been working towards adding additional capacity to the system through projects such as the Maple Ave Relief Sewer (MARS) and Ogden Ave Relief Sewer (OARS). The first stage of the MARS was completed this past spring. The village is also scheduling to complete the initial planning documents for these projects this fall. In addition to the long-term projects, such as adding capacity to the village's system, other ongoing maintenance projects seek to maintain the village's system by preventing blockages and maintaining the existing infrastructure. These projects include the sewer-lining program and and sewer-televising programs. Besides village-initiated projects, residents can also implement various protection measures, such as overhead sewers to protect against basement backups. In order to provide residents additional information on the village's sewer system and future infrastructure improvement plans, we plan on having a separate presentation at a later date with more detailed information. If anyone has any specific questions, I would encourage them to contact the Department of Public Works at 708-579-2328.
Comments