Client: City of Elkhart, Indiana

Location: Elkhart, Indiana

This project replaces three water mains between Elkhart’s North Wellfield storage tanks and the chemical addition and high service pumping facility. Some of the existing mains are more than 100 years old and cross the Elkhart and Western railroad and Christiana Creek. The mains are being replaced with 24-inch diameter ductile iron pipe. The project includes installation of seven 24-inch gate valves and boxes to provide the means to isolate each of the three water mains at each creek crossing.

Donohue evaluated potential pipe materials and construction methods for the City’s consideration. A recommendation was provided based on railroad and IDNR requirements and sub-surface conditions at the project site. The railroad requires a casing pipe at the crossing, and due to the proximity of the creek to the railroad and the steep embankment between, the casing pipe will be extended under both the creek and the railroad.

Trenchless installation methods considered included horizontal auger boring, micro tunneling and pipe ramming with auger boring. Pipe ramming was the method selected to best accommodate the high ground water conditions and gravel/sand seams transversing the horizon where the pipe will be installed.

The existing water mains are located within the flow area of the creek and will be removed as part of the project in order to improve creek hydraulics. The work in the creek requires permits from IDEM, IDNR and the US Army Corps of Engineers.   IDEM construction permit for water facilities and a permit from the Elkhart and Western Railroad were also required.

A fast-track project, Donohue completed bidding documents within 16 weeks from receiving authorization to proceed.