SR 06:176 - Laserfiche WebLink

to the existing pipe to secure and protect the pipe from further damage in future storm flows. To expedite the construction, bids were received on August 14th and a recommendation for award to the lowest responsive bidder will be forwarded prior to the City Council Meeting. It is anticipated that this work will be completed prior to October 15th, which is an imposed deadline from regulatory agencies for work to be completed within the arroyo. Honorable Mayor and Members of the City Council: BACKGROUND During last year's rain storms, the S-6 sewer line that runs under the Arroyo Mocho channel to the 5-6 Sewer lift station, suffered damage. The sewer line is a reinforced concrete pipe, 24-inches in diameter and carries 2.2 million gallons of raw sewage per day. The line is approximately 18-24 inches below the channel bottom and storm flow velocities within the channel were high enough to scour the soil away from around the pipe and concrete encasement. The loss of soil further exposed the line to storm flows which created the potential to wash out the line and dump raw sewage downstream. The pipeline's existing construction is encased in concrete and steel immediately under the low flow channel of the arroyo. However, the existing concrete encasement does not extend under the side slopes of the channel. In an effort to protect the sewer, an emergency contract was let to McGuire and Hester to secure the pipeline in place. Heavy equipment was mobilized to the site and soil was pushed back into place and sandbags were dropped on and around the pipe to anchor it. The pipeline was secured and the sewer line remains in operation. Staff is now working with FEMA and the Office of Emergency Services to seek disaster relief funds to reimburse the City for its cost for this emergency repair work. As part of the long-term fix, design plans have been developed for permanent repairs and the project put out to bid, with bids due to the City on August 14, 2006. Work will include: the removal of sand bags, exposing the pipe and concrete encasement for inspection, performing repairs to the pipe and encasement (if necessary), adding additional concrete and steel encasement around the existing pipe IS-feet into each embankment, the import of soil and re- compaction around the pipe, as well as repair of the channel side slopes. ENVIRONMENTAL PERMITS Staff is also working to secure environmental permits from the regulatory agencies, which include the Army Corps of Engineers, the Department of Fish and Game and the Regional Water Quality Control Board. To help with this effort, we have executed a contract with Mosaic Associates to provide assistance related to the required permitting. Included in the SR06:176 Page 2 of 4