This project involved reconstructing 1,750 feet of sanitary sewer along McKinley Avenue, from Main Street to Tenth Street in the north portion of Lowden, Iowa. The residential neighborhood consisted of older homes and a sealcoat street.
The existing 8-inch sanitary sewers were mainly constructed of clay, which deteriorated and settled over time. That created blockages and also allowed non-sewage surface water and groundwater to get into the sewers. The excess water flow put significant stress on the city wastewater treatment facility.
Originally, the project also included rerouting the flow from McKinley through the Grant Avenue relief sewer by extending this sewer to the intersection of Elm and Jefferson, installing a lift station at manhole No. 6 and abandoning 1,600 feet of original clay pipe from manhole No. 6 to the treatment plant. Capacity issues, however, meant the pipe had to be replaced, not abandoned.
That 1,600 feet of pipe was 10-inch clay pipe in wet, sandy soil with all the same problems the 8-inch pipe had. This pipe, however, was in close quarters, laid along an old creek bed between railroad tracks and a highway. Plus, the pipe was laid well below groundwater level. (The original contractor had great difficulty laying the pipe in 1955 by open-trench methods.)
MMS’ innovative, trenchless solution was pipe bursting. We specified 12-inch, fuse-welded plastic (HDPE) pipe attached to a mandrel and pulled it through the old clay pipe. As the new pipe was pulled forward, the mandrel broke up the clay pipe and pushed it out of the way. This method required obtaining a DNR variance.
Scope of services included final design and construction documents, approvals and permitting, bid letting, surveying and construction administration. In the end, a total of 2,800 lineal feet of sanitary sewer and 50 individual house services were replaced.