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TO: Mayor Thomas J. Weisner
FROM: Jason Bauer, P.E., Engineering Coordinator
DATE: September 20, 2016
SUBJECT:
To approve a change order for additional work on the Lincoln Avenue CIPP Contract in the amount of $74,000.00. This additional work is required to complete the contract that was awarded to Visu-Sewer of Illinois, LLC on March 22, 2016. This project is located along Lincoln Avenue from Spring Street to Superior Street in Ward 2.
PURPOSE:
This change order is required to facilitate the lining of the sewer; in the current state the sewer cannot be lined due to an uncontrollable amount of groundwater infiltration. When the contractor attempted to line the sewer earlier this year, there was a significant amount of flow in the pipe, which was only slightly reduced when the sanitary sewer flow was diverted to another sewer. Upon closer inspection, it was discovered that the flow was due to groundwater infiltration seeping through the joints. Two approaches were identified for controlling the groundwater seepage; de-watering or joint grouting. Due to the severe cracking in the pipe, not only was the cost of grouting higher than de-watering, but the contractor could not guarantee that it would completely resolve the issue. De-watering via the insertion of well points along the sewer line will be required to draw the water down to a level that will allow the liner to be successfully installed. This quote also includes any necessary restoration efforts required to backfill the de-watering locations. In addition to providing structural integrity to the pipe, this project will also reduce the groundwater infiltration and corresponding amount of clean water that is sent to Fox Metro for treatment. The location map is shown as Exhibit A and the change order is attached as Exhibit B.
BACKGROUND:
This section of sewer is deteriorated and lining will be required to avoid the high cost of replacing the sewer at depths up to 25 feet. An emergency rep...
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