The City of Ventura in California is considering the initial results of a test focused on upgrading its wastewater treatment technology to a more energy-efficient alternative.
As part of the test, the city has been evaluating a system from the Pasteurization Technology Group (PTG). What makes PTG's technology unique is that it uses heat produced by renewable energy to disinfect wastewater. The system uses natural gas and digester gas to run the turbines used to generate electricity; the heat exhaust from those turbines runs through heat exchangers that disinfect the water.
Right now, the evaluation system is being used to handle about 5 percent of the city's average daily wastewater flow. That's about 500,000 gallons.
The early results show that a full-scale system could generate enough electricity to power the entire facility, according to the city. That annual electric bill is about $900,000 per year, but it would cost about half that amount to source the natural gas needed to run the PTG technology, so that's about a 50 percent decrease. In addition, the city would also save money on wastewater treatment chemicals, which cost it about $250,000 annually, according to the early feedback from the test.
"Ventura Water is continually seeking improvement of our treatment and operational processes," said Ventura Water General Manager Shana Epstein. "We are pleased to be partnering in this important project that is demonstrating effective disinfection without chemicals as well as a potential for significant operational savings, if fully implemented, down the road."
PTG hasn't exactly won the deal, just yet. The city is waiting for the testing agency, Carollo Engineers, to provide a full performance analysis of all the test results before Ventura plans to move forward with alternative water disinfection technologies. Among other things, the city plans to look at whether or not it should use more or less biogas alternative to run the systems and the associated cost implications.