Laserfiche WebLink
be complicated by the depth of the sewer and the mature service area. West of Lost <br /> Bridge Road the sewer lies beneath Route 121 (Lake Shore Drive) and parallels Lake <br /> Decatur. A pipe failure in this area has the potential to discharge sewage into Lake <br /> Decatur. <br /> Please note that the corrosive atmosphere mentioned above for the East Trunk, West <br /> Trunk, and 16th Street sewers needs to be confirmed. Industrial flows to the Lake Shore <br /> Drive sewers have been modified over the last 20 years. It is possible that the corrosive <br /> atmosphere that caused the damage seen in the inspection videos is no longer a concern. <br /> If future corrosion issues are not indicated, this could affect the recommended actions <br /> described below. <br /> 1.1.6 Recommendations <br /> Recommendations for the Lake Shore Drive Sewer arerou ed into two division <br /> g p s, but the <br /> improvements could be performed as a single project: <br /> (a) Division A <br /> Perform trenchless rehabilitation on the East Trunk Line, the 16th Street Branch south <br /> of Vanderhoof Street, and those pipes in the 16th Street Branch showing active <br /> infiltration. All pipes should be cleaned and defective service taps repaired. Manholes <br /> should be treated with calcium aluminate gunite in corrosive areas, or other spray- <br /> applied coatings as appropriate. Sewer replacement should be performed instead of <br /> trenchless rehabilitation where conditions allow this method to be more cost-effective. <br /> The estimated project costs for Division A are $5,821,700. The annual O&M cost is <br /> expected to remain unchanged. <br /> (b) Division B <br /> Perform trenchless rehabilitation on the West Trunk Line. All pipes should be cleaned <br /> and defective service taps repaired. Manholes should be treated with calcium <br /> aluminate gunite or comparably performing spray-applied coating. Sewer replacement <br /> should be performed instead of trenchless rehabilitation where conditions allow this <br /> method to be more cost-effective. The MLK branch should be treated with targeted <br /> pipe replacement, manhole replacement, and service tap repairs. The estimated <br /> project costs for Division B are $5,241,000. The annual O&M cost is expected to <br /> remain unchanged. <br /> 1.2 McKinley Avenue Sewer <br /> 1.2.1 Summary <br /> The McKinley Avenue Sewer is the primary combined sewer tributary to the McKinley <br /> Avenue CSO. The pipe diameters range from 42 inches to 72 inches. Televised <br /> inspections of this sewer show multiple mineral deposits in almost every pipe, often <br /> Page 2 of 119 BGM 11-050 <br /> Critical Sewers Rehabilitation City Project 2011-03 <br /> Facilities Plan Amendment <br />