California wastewater plant will convert liquid food waste to energy

The Encina Wastewater Authority (EWA), Carlsbad, Calif., has awarded a contract to Phoenix-based J.R. Filanc Construction and a partnership with Liquid Environmental Solutions, Irvine, Texas, to build an alternative fuel receiving facility that will recycle waste cooking oil and other food wastes. The organic materials will be used to produce renewable energy to help EWA achieve energy independence.

EWA currently produces nearly 80 percent of its 2.2 megawatt (MW) annual electricity demand from biogas that is created during the wastewater treatment process, a biological process that relies on bacteria to decompose biological and chemical waste. This process results in the release of methane gases that are recaptured through EWA’s PureEnergy program and are used to power biogas engines that generate electricity at EWA and deliver heat to other EWA system processes.

“Through our joint venture and design-build contract with J.R. Filanc Construction and HDR Engineering, and a fuel delivery partnership with Liquid Environmental Solutions, our commitment to the Alternative Fuel Receiving Project means that EWA will soon be a net-zero energy consumer. Using resources embedded in the wastewater stream to achieve energy independence is key to sustainable water resources management,” says Kevin Hardy, EWA’s general manager.

The Alternative Fuel Receiving Project will deliver fats, oils and grease, liquefied food waste and other higher strength digestible organic substrate to EWA’s Water Pollution Control facility. This waste will be anaerobically digested to yield additional biogas fuel to supplement current unused digestion capacity. EWA anticipates the project will pay for itself during the first four4 years of operation.

“This investment reflects EWA’s mission to provide sustainable and fiscally responsible services while maximizing the use of alternative and renewable resources,” says Jim Poltl, chair of EWA’s Board of Directors. “Infrastructure investments that result in outstanding environmental outcomes and enhance our energy self-sufficiency help EWA save money on operating costs and keep rates low for all our customers here in north San Diego county.”

Construction of the Alternative Fuel Receiving Facility is expected to commence during the first quarter of 2014 and will take about six months to complete.