Westerville 24-inch Waterline
EMH&T provided construction administration and a resident project representative for the installation of approximately 3,000 linear feet of 24- inch mechanical joint ductile iron pipe providing water transmission service for the City’s Water Department. Approximately half of the 24-inch transmission line was installed within asphalt pavement and required pavement replacement. The project featured a 150 linear feet crossing of Alum Creek, a sensitive riparian environment. At the Alum Creek crossing, in addition to the 24-inch transmission line, a 16-inch ductile iron pipe was installed for raw water service. The Alum Creek crossing was performed in an innovative two step method that allowed constructing one half of the crossing in each step. Both steps consisted of building a temporary earth filled cofferdam bounded by on two sides by two sets of trench boxes paralleling the water lines and bounded on the third side by steel plates installed perpendicular to the water lines. During both steps Alum Creek flows were diverted around the cofferdam within the existing channel.