The City of Evanston Utilities Department will be rehabilitating the combined sewer on Prairie Avenue between Central Street and Grant Street (see map below) June 12-July 15 with a temporary traffic pattern in effect. Prairie Avenue will be reduced to only one lane of traffic with a flagger on site to direct traffic. This work is part of a larger project to improve the reliability of the combined sewer system in several areas of Evanston. The city was awarded a low interest loan from the Illinois Environmental Protection Agency to fund this $3 million project, which will allow the city to complete the project without raising sewer rates.

The city has contracted with Insituform Technologies USA, LLC (Insituform) to rehabilitate approximately 2,175 feet of 48” diameter brick sewers on Prairie Avenue. Rehabilitation work includes installing a cured-in-place pipe (CIPP) liner inside the existing sewer main. When completed, there will be a new fiberglass pipe installed within the old existing brick sewer. This process is generally less disruptive and the work can be completed much faster than if the sewer were excavated and replaced.

In general, the contractor’s work area will be at the manholes located on Prairie at the alleys mid-block between the east/west streets. In each block, the contractor will insert the liner through the manhole to rehabilitate the sewer to the north and then the next day insert the liner through the manhole to rehabilitate the sewer to the south. It will take approximately 16 hours each day from the time they begin the installation of the liner until the liner is fully installed.

When the liner is inserted into the sewer main in front of your property, it will seal the building sewer service connections and prevent them from flowing into the public sewer. The contractor will perform by-pass pumping of the sewer services as necessary to prevent any sewage from backing up into your property. Once the liner is completely installed, the contractor cuts the liner where the sewer services are located reestablishing flow from each property to the public sewer.

The resins used in the lining process are not new. They are the same resins used in the fiberglass industry for many years. These resins contain a chemical called styrene that hardens when heated. Although styrene is not a pleasant odor, it is not dangerous at the levels at which people can detect it. If you smell the styrene while the contractor’s personnel are working in your area, do not be alarmed. To help prevent the smell from occurring in your building, pour a gallon of water into each basement floor drain. This keeps the “trap” full and prevents sewer gases from coming into your building. Because the water in the drain trap evaporates, this practice should be done regularly.

TENTATIVE SCHEDULE
Insituform and their subcontractor, Sheridan Plumbing, have already begun cleaning the sewer mains on Prairie. ”No Parking” signs will be posted in the work areas to provide the contractor a safe work zone while still providing a lane of traffic. The lining operation to rehabilitate the sewers is scheduled to be completed between June 12 and July 15, 2013.

CONTACT INFORMATION
This project will be monitored and inspected by the City of Evanston Utilities Department. Please direct any questions to Mr. Mark Steinbuck, Sewer Division Supervisor, 847-448-
8219.