VALPARAISO, Ind. (AP) — Valparaiso is looking at using food waste to increase the amount of methane now generated at its sewage treatment facility, a move that would cut the plant's utility bills.
The city's Utilities Board voted this past week to approve a contract with MWH Americas Inc. of Chicago for a feasibility study, The Times of Munster reported Sunday.
Assistant Utility Director Steve Poulos told the board the additional methane could be used to power a turbine that would generate electricity and offset the plant's $340,000 annual electric bill.
Methane created from the processing of sewage already is used to heat all the buildings on the treatment plant campus and the tanks used to break down sludge, saving the city about $500,000 over the past decade, Poulos said. Natural gas has to be used to supplement the methane in the winter, but the system has reduced natural gas costs by about 20 percent. That's in addition to lower costs resulting from a roughly 50 percent reduction in the cost of gas in recent years.
Electric costs, however, have increased by about 30 percent since 2002, but the sewage treatment has kept its costs about the same by upgrading equipment, optimizing the operation and educating staff on efficiency. Without those measures, the electric bill would be about $100,000 a year higher now, Poulos said.
Northern Indiana Public Service Co. recently increased its electric rates another 10 percent, but Poulos said he hopes to offset that by adding food waste to the digestion process. The additional methane can be used to generate electricity to operate the equipment, which accounts for 80 to 90 percent of the plant's electric bill, he said.
The city of West Lafayette is using a similar system and is saving about 20 percent on electricity. Similar savings in Valparaiso would be as high as $75,000 per year, Poulos said.
The MWH study will look at the existing operation to see if it can be retrofitted to use the food waste and evaluate possible sources of food waste, such as Valparaiso University, grocery stores and restaurants.
Not only would the city save money on electric costs, it also could generate revenue from tipping fees to accept the waste. Poulos said the university already is pulping its food waste and is interested in participating with the city.
"It's the next step in our push for energy conservation," Poulos said. "I would love to see it power our facility from what we produce. It would reduce the cost for the facility and for the ratepayers."
The study will cost $85,000 and take three to four months to complete.
Poulos said the use of similar systems is more common in Europe, which has less room for landfills than the U.S. He's hoping the savings will make up for the cost of installing the system in three to five years, he said.