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PUBLIC WORKS - SANITARY SEWER CIP <br />The existing sanitary sewer system consists of pipe ranging between 1.25" to 21". Pipe materials include <br />PVC, VCP, and Truss. The majority of the sanitary sewer was installed between 1963 and 2011. <br />Due to the City's proximity to Lake Minnetonka and other water bodies, many of the City's sanitary sewer <br />lines are below the groundwater table and are susceptible to infiltration. Infiltration is caused by leaks in <br />pipes, manholes, and service connections that allow groundwater to penetrate the system. Roots penetrating <br />the sewer can also be a problem. <br />The life cycle of a sanitary sewer system depends on several factors including the quality of construction, the <br />type of material used in construction, and the proximity of landscaping such as trees and shrubs that may cause <br />root issues. In growing communities it is also possible for a sanitary sewer to become functionally obsolete if <br />the size of the main is not adequate to accept the flow. In general, older sanitary sewer systems that have <br />infiltration issues need to be improved with either sewer lining or complete replacement. In most cases, the <br />preferred method depends on the condition of the lateral services. Although both sewer mains and services <br />can be lined to eliminate infiltration, it may be more cost effective to replace the main and services if <br />significant infiltration exists in a majority of the service lines. The City is currently being charged an I&I <br />surcharge from the MCES. Work performed as part of the CIP that reduces I&I can be counted against the <br />surcharge. <br />Projects identified in the Sanitary Sewer CIP include the costs associated with maintaining and improving the <br />sanitary sewer system including lift station updates, Grinder Station updates, Generator improvements, sewer <br />lining, and equipment purchases. The City currently has 45 lift stations that it is responsible for maintaining. <br />Typically, the City plans for rehabilitating two lift stations and replacing one generator per year. <br />16 <br />