The Greater Peoria Sanitary District is exploring a way to make waste into a renewable source of energy and revenue.
The methane gas generated by the district’s wastewater is currently “flared” off into the atmosphere, ejected through a continuous flame like the ones you see on top of oil refineries. But the process of Renewable Natural Gas, or RNG, proposes another path for that methane: converting it into usable natural gas.
“The challenge from our trustees has been: ‘let’s explore these waste to resource opportunities here,’” said District Executive Director Brian Johnson. “‘And see if we can’t figure out a unique way for a government to generate revenue in order to reinvest in the system and keep our rates around the national average.’”
The Sanitary District is currently in the “due diligence” phase of this project. They’re exploring a partnership with the Texas-based company Trillium Energy to build and operate the plant on-site that would gather and process the methane.
“Instead of going into a flare, it will go into an H2S reduction process, then gets compressed and dehydrated, then goes through what we call a scrubbing process,” Johnson said. “To clean the gas so that it is of a nature that can be put into the natural gas grid for Ameren. Then it’s compressed, put back into the natural gas grid and used by whoever needs it.”
It’s a process that’s been used widely in landfills, but Johnson says the Peoria Sanitary District would be on the “forefront” of its use in wastewater.
The potential benefits of implementing the program are both environmental and economic. Repurposing the methane would greatly reduce the emissions created by the district. It also turns waste into a new revenue stream, Johnson says very early estimates place the additional gains at as much as $50,000 a month.
“That’s just a generic number,” Johnson said. “I’d say it could be much higher, depending on how we are able to rehabilitate some of our anaerobic digesters. And obviously, the more gas we create, the more renewable natural gas is created, and the more revenue can come into the system.”
Johnson says the new revenue would be reinvested in the system and infrastructure, some of the equipment utilized by the Sanitary District is almost 100 years old and would benefit from rehabilitation.
RNG is just one of a number of initiatives the Sanitary District is exploring, including running as much as half the facility on solar power and processing fat and grease from restaurants into a product that can be sold for additional revenue.
Johnson says RNG is still in the “due diligence” phase and there’s no solid timeline yet.
