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Home My WebLink About4D, I&I Work Plan ~ ~HILLS City Council Agenda Packet Item: Approve the Inflow and Infiltration work plan for 2008 and authorize staffto contract with Bonestroo to perform additional study for the City in an amount not to exceed $18,300 April 14, 2008 ~ ~HlLLS Request for Council Action Prepared By: __l5x_i~_H~~__~_!g,~_ Dept.: Engineering Council Mtg, Date: ............................... "" 4i14;Ojf" Final Action Needed By: Agenda Item: Budgeted Amouiit, . . .. .. ....... .... ....$100;100 Actual Amount: m"m"~"_""~"-"-$3a;000.. Funding Source:, ...... n..... .... .....u.-.-.-.-....-.:-::-~~.~I!~~ri:~_~_~_~~__f_~~~ the Inflow and Infiltration (1&1) work plan for 2008 and authorize staff to contract with Bonestroo to perform additional study for in an amount not to exceed $18.300. the Inflow and Infiltration (1&1) work plan for 2008 and authorize staff to contract with Bonestroo to perform additional study for in an amount not to exceed $18,300. x From Civil Engineer Kristine Giga dated April 10, 2008 No,: No.: Recommendation: Recommendation: x 2008 Work Plan (map) f-_6Jn-~5~I~I;J'Q}_i?!I~[gn~DiIlliiliiillnrlQili2EJZilll;;E?1_._..m.._.__._.___________.....___..__..._______.___..._______m _ _ ____mm__._n_______________ * $100,100 has been included in the 2008 budget for work relating to III. The consultant costs are $18,300. -pIease-refermtothe attached-- memorandum for additional direct expenses as a part of the UI study. 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 1&1 4/10/2008 Page 2 like to install a monitor at Lift Station 11, and possibly some other lift stations, to record exact run times of the pumps. (For example, be able to tell that a pump ran from 1:00 p.m. to 1:04 p.m., and again from 1:15 p.m. to 1:20 p.m.) Staff will calibrate the lift stations at the same time the flow meters are installed. Manhole inspection and rehabilitation proiect: Public Works staffwill inspect 147 manholes identified on the attached map. Staff will compile information from all ofthe completed inspections and determine which manholes need rehabilitation and/or repair. Manholes needing minor work, such as the installation of a chimney seal or replacement of a casting, will be completed by Public Works crews. Manholes needing major structural rehabilitation will be contracted out. Staff anticipates that this project would be ready to advertise in early summer; this project will be brought back to council to authorize advertisement for bids. Smoke testing: Smoke testing is one way to determine ifthe 1&1 is the result of Infiltration (ground water) or Inflow (sump pump or storm sewer connections). This is the most efficient and cost effective way to locate and identify the number of rain leaders from buildings that are connected to the sanitary sewer. Smoke testing involves forcing smoke. filled air through the sewer line. The smoke will fill the main line plus any connections following the path of the leak to the ground surface revealing the location and source of the problem. At this time, the consultant recommends the following areas, also identified on the attached map, be included in smoke testing: the area flowing to Temporary Meter 3 (the Glenarden neighborhood) and the area flowing to Lift Station #11 (northwest comer of the City.) Develop and begin sump pumP inspection program: City staff has contacted Mounds View, New Brighton and Little Canada requesting information on their sump pump programs. We have begun to receive responses and information from these cities. Bonestroo has also provided an estimate to assist the City in developing a program and training staffto complete inspections. Staff will continue to compile this information and present a proposed program to the City Council for approval. Sanitary Sewer televising and lining proiects: Public works crews are continuing to televise the City's sanitary sewer lines. The videos will be reviewed, and sanitary sewer mains identified as good candidates for lining will be combined into a sewer lining project. We anticipate this project to be a joint project with the City of Roseville, as they also are planning a sewer lining project for 2008. FINANCIAL IMPLICATIONS All costs for this additional study will be paid for using sanitary sewer funds budgeted for inflow and infiltration reduction; $100,100 was included in the 2008 budget for these purposes. The findings of each step will be brought to the City Conncil once the additional study is complete. The consultant costs are $15,000 to assist City staff with the additional study, plus $3,300 for assistance with the development of a sump pump program. 1&1 4/1012008 Page 3 There will also be additional, direct equipment rental costs for this work: . Flow meter rental: The meter rental for four to six weeks for all three meters is estimated between $8,000 and $11,000. . Lift station monitors: Rental for these monitors is estimated at $700 per month per monitor. At this time staffhas determined that one monitor is needed; we may fmd that additional monitors will be needed after processing some of the additional data that is gathered. . Smoke Testing: Staff estimates the cost of smoke testing for the proposed area to be $8,000. Staff will bring proposed manhole repair, sanitary sewer lining or other identified improvement projects to the City Council for authorization at a future meeting; estimates for these projects are unknown at this time. RECOMMENDED COUNCIL ACTION Approve the Inflow and Infiltration 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. ,,~""""...~til,...,~~ '_~~' ...."'~.J<,'"iff,X;~::?~..~~~~JCi1.~,.'fb,{'O""';?~~~"";<:5f~i:Fi'1';:",';=,T",;"""":"~"","yq>"""~~~",.""~,.,;:""y:-~"",,,,,,,,,,,;=,,,,~:r.'t~~~ 'l3t~.", "',_._." ~~ ~~ :/ , 10 ~'=# 7 \. (>r ~ \.'.:!' <:)