California Water Utility Removes Perchlorate, VOCs
The Lincoln Avenue Water Co., recently started up its 2,000-gpm perchlorate removal system at its two wells in Altadena, Calif.
The new system uses a combination of High-Flow vessels from USFilter Westates Carbon and PWA2 perchlorate removal media jointly developed by California’s USFilter and Rohm and Haas of Philadelphia to reduce perchlorate to non-detectable levels. The system startup enables the water company to re-open the two wells and to meet the higher water demands of summer.
More than a decade ago, Lincoln Avenue installed a 2,000-gpm carbon removal system from another manufacturer to remove VOCs (specifically trichloroethylene, tetrachloroethylene and carbon tetrachloride) and other organics from the water system.
"Before installing the carbon removal system, trichloroethylene levels used to reach as high as 102 ppb," states Robert Hayward, general manager of Lincoln Avenue Water Co.
The existing carbon removal system will work in tandem with the new perchlorate removal resins to ensure that the water produced meets all state guidelines. NASA is funding the construction and operation of both removal systems.
"Perchlorate levels increased significantly this year, to more than double the acceptable Public Health Goal," continues Hayward. "As a result, the wells remained off until water provided to our customers met the required safety levels. Water samples taken from our well-head in April and May indicated perchlorate levels were between 8 and 15 ppb. This new system will reduce perchlorate levels to non-detectable levels."
As part of the new multi-year perchlorate removal contract, USFilter will use disposable ion exchange resin technologies to treat the water. The combined technology will help keep operating costs below $170 per acre-foot.
The new series of HP1220 High-Flow vessels doubles the flow rate of water through a 12-ft diameter vessel, reducing the number of vessels required for treatment by half. The small footprint configuration requires less space for the treatment plant operation.
USFilter is pairing the vessels with 600 cu.ft. of ion-specific resin capable of removing up to 200 ppb of perchlorate from well water supplies, reducing contamination to below non-detection levels. Compared to other perchlorate removal technologies, the new resins reduce the treatment systems’ operating costs to below $200 per acre-foot treated, eliminate generating a contaminated brine waste and provide substantially more total treatment capacity. Once the media is spent, the resin is destroyed to prevent future groundwater re-contamination.