Dec. 20, 2013 – In the not-so-distant future you may be able to get your natural gas at your local wastewater treatment plant—or at least the Ithaca Area Wastewater Treatment Facility (IAWWTF) is working hard toward making that possibility a reality. Thanks to some recent upgrades, the facility is now able to generate around 60 percent of its own energy by producing biogas, although in the future it may become more efficient to sell that biogas for vehicle fuel.
How exactly does the wastewater plant go about making biogas? IAWWTF’s Chief Operator Dan Ramer explained: “A wastewater treatment plant harvests nutrients out of the water. We use a biological system that absorbs nutrients and transforms them into a bio-solid. That material is put into an anaerobic digester, and when you anaerobically digest solids like that [the process] produces biogas.”
Basically, while cleaning your wastewater before releasing it into Cayuga Lake, the plant is conveniently able to produce biogas, which it then uses to meet its own energy needs. In addition to treating wastewater and producing energy, Ramer explained, “We also take in septic waste, grease trap waste, some dairy waste, and hydrolyzate from a carcass digester at Cornell. The easiest way to think about this is that we harvest carbon.”
IAWWTF is an inter-municipal agency, so it services the hamlet of Varna, the town of Ithaca, and the city of Ithaca. In addition, the facility takes in septic waste from many of the surrounding rural communities that do not have their own wastewater treatment facilities.
The plant had previously been producing about 30 percent of its own energy needs, but a series of recent upgrades to the tune of $8 million have increased the plant’s energy production to make it about 60 percent energy self-sufficient. Ramer said, “We needed to fix some stuff here and also we needed to upgrade our biogas system.”
Prior to its recent makeover, the plant had relied on a biogas system installed when the current facility was built in 1987. The Caterpillar engines that powered the system were becoming obsolete, so upgrading the biogas production equipment was a priority. “We installed new mixing equipment in our digesters,” Ramer said, “so that we have a more efficient means of making gas. We had a digester cover problem so we changed that so now we have a safe way of storing our biogas. And, we put in microturbines instead of the Caterpillar engines. That’s the real central component of the biogas side [of the upgrades].”
In addition to biogas system upgrades, IAWWTF worked to reduce its energy consumption needs. Ramer explained, “On the energy savings side we redid all the lighting to high-efficiency lights, we upgraded a lot of the heating and ventilation equipment, and we had the whole building enveloped to fix caulking and leaks.”
The project initiated with studies in 2009 and work finally began after a year and a half of contract negotiations—a task that Ramer notes is exceedingly difficult when dealing with three different municipalities. Now the project is in its final stages: “We’re right around 50 to 60 percent [energy self-sufficiency], and we have a couple more improvements in the works, so probably by the end of 2014 we’ll be up above 70 percent if everything goes well.”
In the future, Ramer says the plant is hoping to begin further purifying the biogas so that it has a lower carbon dioxide content and can be used to power vehicles. In that scenario, the plant would begin selling biogas instead of using it to meet the plant’s own energy needs as that would be the more economical option. “Right now,” he said, “that market doesn’t really exist in Ithaca but if we could build the possibility then vehicles could be retrofitted to use that fuel.”
By harvesting carbon and producing clean energy, IAWWTF decreases the total amount of greenhouse gases in the environment. “We’re actually a greenhouse gas sink,” Ramer said, “so we’re pulling carbon out of the environment and making sure it doesn’t become a greenhouse gas. Our vision for this facility is to protect my ratepayers and my community from other possible influences that are negative. If I can help the community lower its greenhouse gas footprint that means we become a clean, greener community.” •
This article is originally published at Ithaca.com.
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