During the rehabilitation of Lift Station 10 under the current agreement with Wharton-Smith, Inc., the 20-inch 90 degree tee at the end of the influent 20-inch sanitary sewer was removed as required during renovation. It was noted that the influent 20-inch sanitary sewer is in poor condition (corroded) and should be rehabilitated.  Rehabilitation of the collection system was not part of the original scope of work for the rehabilitation of Lift Station 10 nor was the 20-inch sanitary sewer outside of the wet well part of the re-configuration of any piping required for the new configuration of Lift Station No. 10.

Based on an evaluation by the engineer Mark Drummond, of C-Solution, he recommends the District rehabilitate the 20-inch influent ductile iron pipe (DIP) as soon as possible to avoid pipe failure.  While it’s impossible to predict the timing of a failure and the 20-inch DIP may continue to perform its intended function for years to come; however, the risk of failure is high as well as sewage being transferred from Singer Island that passes through this particular pipe, into Lift Station No. 10 and there are no alternate routes.  Wharton-Smith provided cost estimates for both repair and replacement of this pipeline which were estimated at approximately $36,272 and $129,366 respectively.

Again, while the cost of repair or replacement is not part of the original agreement with Wharton Smith, the repair costs will be covered in the Utility District Capital Plan for Lift Station Rehabilitation.

Staff is recommending Wharton-Smith move forward with repair of the 20-inch influent ductile iron pipe at a cost of $36,272.00.