 
Wastewater Goes Green in Akron
December 2007, Electrical Worker
 If recycling and reusing are the watchwords of these green times, IBEW members are out on the cutting edge of new technologies like wastewater digestion, which reuses and recycles solid waste to generate power.
Akron, Ohio, Local 306 members helped retrofit a 20-year-old compost plant into a digester that produces power. The result is a plant opening soon in Akron that teams KB Compost Services with a German bio-energy company using a state-of-the-art methane digester that fuels a 350-kilovolt generator.
The plant once mixed the solid waste from the Akron sewage treatment plant with tree bark or sawdust to make fertilizer sold to golf courses or dumped into landfills. This labor intensive process, which involves turning the mixture until it is done and ready for transport, also could unfortunately be smelly, said Akron Local 306 Press Secretary Robert Sallaz.
“You can smell most of these plants two miles before you get there,” Sallaz said. “This process gets rid of the sludge and the stink, and it makes electricity.”
The basic process is not new. It was invented in the early 19th century and is in use in Europe. But in the United States, such plants are unusual, Sallaz said. The Akron plant utilizes a technology that allows for the use of 18 percent solid waste versus the 6 percent with earlier sewage biomass plants.
It works through a chemical process that involves mixing the waste with water and bacteria. Through temperature gauges, heaters and controls installed by nearly 10 Local 306 members on the job since last spring, the mixture is raised to a constant temperature, generating gas and pressure to run a biogas engine that in turn powers the 350-kilovolt generator, Sallaz said.
Local 38 member Mark Mewhinney, project foreman, said due to the corrosive nature of the process and the possibility of hazards, they installed PVC-coated rigid conduit underground and several explosion-proof areas with sealed pipes to prevent gas leaks from traveling through the infrastructure.
The digester will use much of the sludge, cutting down on the amount of material that must be discarded, Sallaz said. If the plant runs as expected, plans call for building two other digesters on the site. The underground work for those plants has already been done, said Mewhinney, who works for Doan/Pyramid Electric.
Mewhinney has been working with Local 306 members Jody Murphy, Bob Bartsche, Ray Romano, Jeff Firth and Marty Laich, who helped install the sophisticated system of power sources, transfer switches and motor control centers.
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