Kent DPW Will Tap Gas Energy

July 27, 2007
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GRAND RAPIDS — Four million tons of garbage in the South Kent Landfill are about to amount to something. Kent County Department of Public Works intends to extract the landfill gas at the site and make it available as an energy source for local businesses.

“We’ve done the calculations and determined there is gas out there that will burn, and we’re starting to look for customers who want to use it,” said Ron Landis, director of the county DPW’s Engineering/Utility Services Division.

Landfill gas is the natural by-product of the decomposition of solid waste in landfills. Because of its high methane content, landfill gas can be recovered, processed and used as an alternative to natural gas. The gas can be used either directly by industry or to generate electricity for public consumption.

According to the Environmental Protection Agency, landfill gas can be used to heat greenhouses, produce electricity and heat in cogeneration applications, fire brick kilns, supply medium-BTU pipeline quality gas, and provide fuel for chemical and automobile manufacturing processes. The EPA estimates there are more than 425 landfill gas energy projects operating nationwide, ranging from small-scale community-driven initiatives to multi-million dollar private investment. The EPA considers landfill gas projects one of the most cost-effective forms of renewable energy generation.

DPW Director Doug Wood said the project will create an opportunity for businesses to access lower cost fuel, as well as create an outlet for the DPW. Rather than burning off the landfill gas or letting it escape into the air, the DPW will be able to put it to practical use. Wood said the DPW prefers to use the recovered methane as a fuel for businesses rather than convert it into electricity and sell it to a utility company. 

“For some types of businesses, gas use is one of their biggest expenses,” Wood said.

“Somebody out there in this county needs gas, and we want to sell it to them.” He noted that the price of landfill gas is not only lower, but also less volatile than the price of natural gas.

South Kent Landfill takes up 45 acres of the DPW’s 169-acre property at the corner of 100th Street and U.S. 131 in Byron Township. The landfill is 125 feet high, currently holds 4 million tons of waste and is designed to hold 10 million tons. As the landfill grows and “foments,” Landis said, they’ll be able to retrieve more gas from it — as much as 1,000 standard cubic feet of methane per minute. He calculates it will be 23 to 25 years before the landfill is full, but said it will likely generate methane for another 30 to 40 years after that.

The DPW hired SCS Engineering to assist in developing the project. A feasibility study is under way and a well field is being designed for installation. Ideally, a customer would locate within a three- to five-mile radius of the landfill in order to access the gas. The closer the better, Landis said.

“If a business chooses to use our methane gas, we can negotiate a rate for the gas they need to either cool or heat their warehouse or fire their cement kiln or wood-burner or whatever they want to do,” Landis said. “A company like a Gordon Food Services or Spartan Stores, for example, might want to build a warehouse with a lot of refrigeration. If they located near the landfill, we could cut their energy costs down considerably.”

The DPW is developing the landfill itself, so customers will work directly with DPW staff. The department doesn’t receive any tax dollars from the county; it operates as a business supported by the fees it charges to local units of government for solid waste management services and water and sewer system construction, inspection and maintenance. Profits made flow back into the department’s general fund, Wood said.  

“We own and operate the landfill. We’re willing to make an investment in this project and take the risk, so if there are rewards, we will get that, too,” Wood acknowledged.

A gas extraction system is not yet in place because the South Kent landfill has not reached the threshold of 15 mega-grams of non-organic methane compounds, Landis said. Once that threshold is surpassed, air quality regulations require that a gas extraction system be installed so the landfill won’t release too many non-organic compounds into the air, he explained. A gas extraction system will cost the department $300,000 to $400,000. 

The South Kent project is part of the EPA’s Landfill Methane Outreach Program. The EPA estimates that every person in America produces an average of 4.5 pounds of garbage per day. Much of that trash goes into landfills, which are the largest human-related source of methane in the United States. Municipal solid waste landfills, in fact, produce 34 percent of methane emissions nationwide.

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