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MEMORANDUM DATE: April 10, 2008 AGENDA ITEM TO: Mayor and City Council Jim Willis, Interim City Administrator FROM: Kristine Giga, Civil Engineer Greg Hoag, Public Works Director SUBJECT: Approve the Inflow and Infiltration (1&1) work plan for 2008 and authorize staff to contract with Bonestroo to perform additional study for the City in an amount not to exceed $18,300. BACKGROUNDIDISCUSSION On March 31, 2008, staff presented the City Council with the Inflow and Infiltration (1&1) report prepared by Bonestroo, which discussed initial results of the study and recommended next steps. At this time, staff is presenting the City Council with a work plan for 2008. Additional study is needed to better understand the source(s) of the 1&1. Without this knowledge, we cannot confidently recommend an additional 1&1 reduction program to the City Council. Once this is completed, staffwill identify improvement projects for 2008 to reduce the 1&1 entering the sanitary sewer system; these projects will be brought to the City Council for approval. Additional temporary flow meters: Three temporary flow meters are proposed for 2008 in the same locations as 2007 (see attached map); we would like to supplement the data that was collected last year. We anticipate the meters will be in place for four to six weeks, depending on the weather. The meters need to monitor "normal flow" and "high flow". High flow occurs when we receive significant rain events. However, if we have a drier than normal period, the length of time the meters are in place may need to be extended. Flow meter installation will occur in the next few weeks. Calibrate lift stations: Public Works staffwill calibrate the lift stations (establish pump cycle times) to supplement the data collected from the flow meters. In addition to this work, we would \\Metro-inet.us\ardenhil1s\PR&PW\Engineering\2008\Council_ Actions\4-14-08MemoI&I.doc