Biogas typically refers to a gas produced as tiny bugs feed on organic waste in a process called anaerobic digestion, which is an air-tight tank. Organic waste flushed to the wastewater plant (such as dead plant material, bodily waste, and kitchen food waste) can be broken down and converted into a gaseous fuel called biogas. Biogas produced at the wastewater plant is primarily composed of methane (63%), which can be used as a type of biofuel. The biogas is typically used at the plant in internal combustion engines to convert the gas into renewable energy as electricity and heat.
The Racine Wastewater Utility has been producing and collecting biogas for onsite use since the plant went on line in 1938. The plant can currently store 200,000 cubic feet of gas at 50 psi for use in the treatment plant. In 2014, the Wastewater Utility realized a benefit from the value of biogas and from heat recovery of the equivalent of $420,000. The plant produces on average of 200,000 cubic feet of biogas per day to produce enough energy so that about 56% of total energy used is renewable. The result is savings for Utility rate payers on sewer bills.