2022 COMPREHENSIVE PLAN - Laserfiche WebLink

Home

City of Gem Lake Comprehensive Plan GEMLK 140643 Page 68 • Replacing existing manhole covers with solid covers • Repair of mortar between rings • Sealing between manhole castings and the manhole structures at manhole locations outside of the bituminous pavement • Raising the existing manhole casting to provide access • Removal of sewer rod or other obstructions in manholes • Sewer lining in sewer sections with multiple poor and deteriorating pipe joints The City of Gem Lake plans to continue their current operation and maintenance program on the sanitary sewer collection system with the goal of providing an effective and efficient piping network and reduce the potential of I/I entering the MCES interceptor system. I/I direct sanitary sewer connections sources from foundation drains, sump pits/pumps and roof leaders will not be allowed by ordinance from future development. In addition, the City will continue their public education program to discourage these types of connections from existing Gem Lake properties. Table 7-6 – Engineers Estimate of Probable Cost for I/I Investigation and Mitigation Description Qty Unit Unit Cost Cost Manhole Inspection 65 EA $500 $32,500 Manhole Rehabilitation 32 EA $1,000 $32,000 Flush and Televise Pipe 13400 LF $10 $134,000 Sanitary Sewer Metering 1 LS $50,000 $50,000 Subtotal $248,500 30% Contingency $74,550 Total $323,050 7.3.3.4 Gravity Sewer Needs A significant portion of a City’s time and budget is used in areas constructed of VCP. This is a result of the root intrusion of joints in this type of pipe. This is not unique to the City of Gem Lake and is typical of VCP throughout the metro area. Many communities have lined or replaced VCP sewer to eliminate the high maintenance needs often associated with these types of sewers. The City has undertaken projects to line the VCP sewers, but to reduce the strain and work for the sewer maintenance staff, a more aggressive lining program should be undertaken. Maintenance in the sewer system typically involves cleaning the sewer using a combination of jetter and vactor trucks to remove debris from the sewer pipes. Root intrusion in joints of the pipe requires cutting and removal to remove obstructions in the pipe and allow flow of the sewage through the system. Once roots begin to enter sewers, it is very difficult to eliminate the recurring growth. The simple cutting of roots often promotes additional growth. Unmanaged root growth can also cause the VCP pipe to crack, impacting the integrity of the pipe. Cracked pipes allow groundwater and soil into the sewer system, which can cause road collapses. The continued efforts to cut roots in the VCP portions of the system annually results in other portions of the City’s sewer system having a lower priority for maintenance. The League of Minnesota Cities (LMC) Insurance Trust provides insurance coverage for the City to protect against claims resulting from sewer backups and other claims that may result from problems related to the City’s utility services. LMC also provides no-fault