Cal Water held a ribbon-cutting ceremony to commemorate the completion of the final chromium-6 (Cr-6) treatment plant for the Las Lomas system in its Salinas District yesterday.
The event served as an opportunity for customers to learn how this plant provides them with water that meets the new water quality standard for the constituent. Attendees were also given personalized tours of the treatment facility.
In July 2014, the State of California set the country’s first regulation for Cr-6, allowing no more than 10 parts per billion (ppb) of the constituent be in water provided to consumers. Wells in Cal Water’s Las Lomas system have naturally occurring Cr-6 on average of 32 ppb; however, since the two local treatment plants were installed and brought online, the water supply has remained in compliance with the new state standard.
In order to find the most effective solution to remove Cr-6 from the water, Cal Water’s Water Quality and Engineering departments experimented with three types of groundwater treatment options. After taking cost, method effectiveness, waste disposal, and raw water quality all into consideration, the team selected strong base ion-exchange and reduction-coagulation-oxidation-filtration treatment systems.
“We wanted to use an option that was both cost-effective for our customers and also effective in treating the water supply,” said District Manager Mike Jones. “The treatment plants that we have installed will ensure Cal Water customers have access to a safe and reliable water supply around the clock.”
Treating the Las Lomas water supply came with a unique challenge, according to Jones. Since Las Lomas customers only had one other well to draw on, there was a 90-day window to build the treatment plant for this well to ensure customers would not experience an interruption in service due to compliance issues.
“Essentially, we were in a race against time to find a viable solution to treat the water supply. A 90-day installation of well-established water treatment technology is virtually unheard of, but implementing a technology that is still in its infancy, and having a successful outcome is nothing short of remarkable,” said Jones. “We could not have accomplished this without the ingenuity and flexibility of our partners, Envirogen Technologies and Beebe Construction.”
“We are one of the first companies in America to use the strong base ion-exchange to treat Cr-6, and it has worked even better than we could have expected,” said Water Quality Program Manager Rob Thompson. “We will share what we have learned in research and development to help smaller water utilities find effective treatment solutions for their systems.”