03-29-2012 Council Agenda - Laserfiche WebLink

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C"J 515 I,1111c Canada Road, Little Canada, MN 55117-1600 (651) 766 -4029 / FAX: (651) 766 -4048 www.ci.littlecauada.nul.us MEMORANDUM TO: Mayor 13lesener & Members of City Council FROM: Hill Dircks, Public Works Superintendent Lee Elfering, City Engineer DATE: March 21, 2012 RE: Sanitary Sewer Service inspections MAYOR 11111 niescncr COUNCIL Rick Montour John Keis Michael McGraw Shelly Buss ADMINIS'IRA'IY)R Joel R. Hanson City Staff continues to look for inflow and infiltration (I &I) problems in its sanitary sewer system. While the City's flows have remained below the Metropolitan Council's threshold for excessive I &I, dry weather has likely played a role and it is good practice to eliminate as much l &I as possible in order to keep sewer costs down. Last year, the wet spring and early summer resulted in an 18.4% increase in treatment costs paid to the Met Council. Based on that number alone it is obvious that the City has a fair amount of I &I in its system. The Met Council plans to evaluate cities again to determine if further work is needed to eliminate I &l. To date the City has inspected sump pumps, roof leaders, manholes, and its own sewer mains. One potential contributor that has not been investigated is leaks in private sanitary sewer service lines. The property owner owns and is responsible for the sanitary sewer service lateral from the house all the way out to the connection point with the sewer main. Many of these service laterals are made ol'clay or cast iron pipe and past experience has shown some to have had joints or cracks that allow groundwater to enter the pipe and eventually the City's main. Staff believes these services may be a significant contributor to the City's l &I issues. It has video evidence of at least two services that show an estimated 10 -15 gallons of water per minute leaking into the line. In order to get a better idea of how much I &I is coming from private service laterals staff is proposing to fund the televising of a representative sample of services in the City. An article will be in the April newsletter asking for volunteers to have their service laterals televised by a contractor hired by the City. Staff will take a look at who volunteers and whether or not it believes the property would be a good candidate and then will select a number of services to televise. Properties with clay or cast iron services will be preferred