South East Highland Sanitary Sewers

In performing not only the company’s, but also the City of Delaware’s, first design-build sewer project, Kokosing installed 20,350 linear feet (LF) of pipe and 47 lined manholes over a more than five-mile project site that included residential, wooded and agricultural property.

The $9.6-million project also included Kokosing drilling and blasting approximately 6,200 LF of rock at depths up to 20 feet; performing two hand tunnels, two bores under roads, and two bores under railroads for RCP-lined pipes; and installation of 24-, 36-, 42- and 48-inch fiber-reinforced sanitary sewer pipe and 24- and 30-inch expoxy-coated RCP at depths of 12 to 40 feet. The pipe was tied in to existing 30-inch sewer line at the upper end of the project.

The sanitary sewer project utilized corrosion-resistant fiber-reinforced pipe and lined precast manholes in order to protect the materials from long-term exposure to hydrogen-sulfide gases and resulting deterioration. Kokosing’s work provided the city with a completely gravity-fed sewer system with 19,250 LF of trunk line that can handle a capacity of 22.7-million gallons per day of sanitary flow.