A long-awaited sludge-receiving station at the HPOWER waste-to-energy incineration facility opens next month at Campbell Industrial Park to try to reduce the need for landfill space on Oahu.
Mayor Kirk Caldwell and other officials dedicated the $10.6 million injection station Thursday.
The injection contraption, located in the third boiler that opened in 2012, will have the capacity to take in approximately 90 tons of wastewater sludge per day, or more than 26,000 tons annually, city officials said.
Until now approximately 20,000 tons of sludge generated annually has been dumped each year in the Waimanalo Gulch Sanitary Landfill several miles down the road.
The city has also needed to place an additional 20,000 tons of bulky waste in the landfill to help process the sludge there, but that will no longer be necessary and can be diverted entirely into the combustion process, officials said.
The new station will result in annual savings of $1.3 million in disposal costs, plus provide an additional $88,000 in revenue from the recycling of ferrous and nonferrous metals recovered from the bulky waste, the city said.
"The opening of this new facility takes Oahu closer to eliminating our need for a daily landfill," Caldwell said in a release.
The equipment feeds sludge into a hydraulically driven dual piston pump, which pushes the sludge to an injection header composed of 18 valves that alternately open to inject sludge into the boiler feed chute. In the chute, the sludge commingles with municipal solid waste and is then fed into the boiler’s fire for combustion.
The contraption has 3,600 cubic feet of storage, the equivalent of one day’s worth of sludge.
Construction by HPOWER operator Covanta took eight months to complete.
