Akron, Ohio’s industrial past led the U.S. Environmental Protection Agency to issue a federal mandate for the city of Akron to comply with the Clean Water Act of 1972 and end pollution in local waterways.
Because about a quarter of Akron’s existing sewer system had been designed as combined sewers when constructed in the early 1900s, frequent overflows mixed stormwater with sanitary sewage. This mix ultimately emptied into the Cuyahoga River, the Little Cuyahoga River, the Ohio and Erie Canal, and Lake Erie.
The city of Akron created a program called Akron Waterways Renewed! to control combined sewer overflows and improve water quality in nearby rivers. A portion of that plan was to create the 6,240-foot Ohio Canal Interceptor Tunnel, construct three new storage basins, upgrade CSO racks, and upsize and reinforce the main outfall sewer capacity.
The 27-foot-diameter OCIT sections were a feat in themselves, dug with a massive tunnel boring machine and constructed of reinforced concrete pipe. The basins will hold combined sanitary and stormwater overflow until it can be safely released to Akron’s wastewater treatment facility.
Building an influent line
Of particular interest is the design and construction of the influent line to the new Howard Storage Basin (CSO Rack 22) at the intersection of Howard and Cuyahoga streets, which will provide temporary storage of combined sewer flow from the North Hill tributary area. With a 2.4 million-gallon capacity, it is the largest of the three new storage basins.
H.M. Miller Construction was subcontracted for the site work for the Howard Storage Basin, one of Akron’s 34 sewer separation units, as well as relocating the existing waterline to accommodate influent piping.
The H.M. Miller engineering staff saw a potential problem with the original design that called for elliptical RCP influent line to run beneath Cuyahoga Street. They realized there would be difficulty in achieving clearance under the public road, even though the RCP line would be elliptical, and that could lead to an inability of the RCP line to pass the required pressure test specification, according to John Smith, president of H.M. Miller.
Calling on HOBAS
Smith contacted his resources at HOBAS to assist in devising an alternate plan for Howard Storage Basin that would resolve the inherent difficulties surrounding installation and testing using the RCP. Together they came up with a design that saved time and money, tying the Howard Storage Basin into the mainline. In place of the elliptical RCP originally specified to be installed under Cuyahoga Street, the new design called for twin 57-inch HOBAS centrifugally cast, fiberglass-reinforced, polymer mortar pipe that would tie into the OCIT-1 mainline with a concrete collar subsequently designed by the project engineer.
H.M. Miller has a long history of contracts with Akron. The mutual respect that developed between the firm, the Public Service Department, and local engineering firms allowed for the acceptance of this major design change during the construction phase.
HOBAS Pipe USA offers centrifugally cast, fiber-reinforced, polymer mortar pipe, which is inherently corrosion resistant. The company’s pressure and gravity pipe diameters range from 18 to 126 inches.
800-856-7473 | info@hobaspipe.com | www.hobaspipe.com
