Building To Protect Our Environment
Nutrient Removal Wastewater Capital Project
A $21 million, two-year capital improvement project to remove more nutrients from the water treated by the Ventura Water Reclamation Facility came online recently. During the activated sludge treatment process, ammonia is converted to nitrate which, unlike ammonia, is not considered toxic. However, nitrate is a nutrient that in sufficient quantities can affect oxygen levels in receiving waters and, in Ventura’s case, could lead to algae blooms and other ecosystem disruptions in the fragile Santa Clara River Estuary. A 70% reduction in nitrate to protect the Estuary was required by the Los Angeles Regional Water Quality Control Board in 2008 as a condition of Ventura’s discharge permit. In conjunction with the upgrade, the project provided an opportunity to modernize facility infrastructure components and associated equipment, some of which have been in service since the 1960s.
The rates paid by Ventura Water customers fund the capital improvement program, which includes important projects like this one. It represents an investment by our community to protect our local water resources and will pay dividends today and serve future generations tomorrow.
September 2011 Nutrient Removal Project Progress Report (pdf 6178KB)
October 2010 Nutrient Removal Project Progress Report (pdf 5158KB)
June 2009 Nutrient Removal Project Progress Report (pdf 6564KB)
In June 2012, Ventura Water announced the initial results of a new non-chemical, energy efficiency technology pilot project that will potentially replace the current chlorine-based disinfection process in use at the Ventura Water Reclamation Facility. The project was conducted in partnership with the Pasteurization Technology Group whose pioneering technology uses heat generated by renewable energy to kill harmful organisms, the final step in the wastewater cleaning process.
The new technology uses natural gas combined with digester gas (a natural by-product of wastewater treatment) as fuel to drive a turbine (or turbines) to generate electricity. The hot exhaust air from the turbine (energy that is typically wasted) is then passed through a series of heat exchangers that increase the temperature of the wastewater to a level that disinfects the wastewater stream. The disinfected water is then cooled to a safe level by transferring the heat of the disinfected water to the incoming water – reusing the energy over and over.
A full-scale design of the system has the potential to generate enough electricity to power the entire facility, which currently costs approximately $900,000 per year. Early estimates show that the amount of natural gas required to run the system would cost about half this amount, saving approximately $450,000 annually. Operational savings are also expected from the reduction of chemical costs, which currently run $250,000 per year.
As part of a continuous improvement effort, Ventura Water began evaluating disinfection options several years ago with PTG’s emerging technology being identified as the lowest-cost alternative in a study led by Carollo Engineers, experts in wastewater engineering. As a result, a small-scale PTG evaluation unit was installed at the reclamation facility and has been disinfecting 500,000 gallons or about 5 percent of the average daily flow of wastewater per day since December 2011. The evaluation unit has been undergoing extensive tests to prove that it meets the Ventura Water Reclamation Facility’s stringent standards for water safety. Design parameters are also being analyzed to disinfect the full wastewater flow of 7 to 9 million gallons per day and to optimize energy efficiency and generation. A full performance analysis of all testing results will be reported to the State prior to moving forward with the program.
City Managers Report to City Council: Wastewater Pasteurization Technology Pilot powerpoint (June 18, 2012 - pdf 228KB)
Wastewater Pasteurization Technology Pilot Fact Sheet (June 19, 2012)
VC Star Ventura Water tests new wastewater treatment technology (June 22, 2012)