The feasibility of small communities using point-of-use (POU) treatment units instead of central treatment to remove arsenic from drinking water is being tested in a rural suburb of Sacramento, Calif., under a project being conducted by NSF International in coordination with state drinking water authorities, the California Rural Water Association, the Water Quality Association and consultants.
Funded by grants from U.S. Environmental Protection Agency (EPA) and the California-based National Water Research Institute, the year-long project is taking place in Grimes, a town of roughly 125 connections with arsenic levels averaging about 25 micrograms/L. Project coordinator Gordon Bellen explained that in addition to testing the performance of a particular POU technology (aluminum oxide), the study is designed to demonstrate each step a community would need to take to implement the POU option and how much it would cost. Implemented with the support of "a very cooperative town council," the project began last fall with a pilot study and continued this year with the installation (at no cost to users) in commercial and residential connections of NSF-certified under-the-sink units provided and serviced by Ohio-based Kinetico that utilize both the arsenic-removal cartridge as well as one with granular activated carbon to control for taste, Bellen said.
Each unit includes a separate tap to be used for drinking, cooking and making ice while leaving the regular tap limited to nonconsumption uses such as dishwashing. Bellen said each unit was verified upon installation as achieving nondetectable arsenic levels and features automatic shutoff at 500 gallons of use. All cartridges will be replaced at six months of use, however.
Bellen said the project is the first to assess the POU compliance option in "a real community" of homes as well as varied commercial properties. He noted that a handful of homes either refused to participate or already had different POU units installed, raising a question about what constitutes full coverage under EPA's criteria for the POU option.
Results are expected to be reported by year's end, he said, and the community will have the option of having the treatment units removed or continuing to manage them on its own.
NSF is also overseeing the field testing of other arsenic treatment technologies in Pennsylvania and Alaska through the joint EPA/NSF Environmental Technology Verification (ETV) Drinking Water Systems Center (DWSC).
In partnership with the Pennsylvania Department of Environmental Protection's effort to develop innovative environmental technologies, the center has developed a cooperative study of adsorptive media that involves three utilities found to be representative of other small community water systems in the state with arsenic problems.
Gannett Fleming of Harrisburg was scheduled to begin field tests this month in Carroll Township's Orchard Hills treatment plant, the Sellersville Borough Water Works and the Hilltown Township Water and Sewer Authority. Technologies to be tested were provided by ADI of New Brunswick, Canada; Ohio-based Kinetico (with Alcan Chemicals) and Colorado-based Water Remediation Technology.
In Alaska, DWSC is working together with the University of Alaska's Small System Training and Technical Assistance Center to test an ozonation/filtration system in Wasilla, Alaska, starting in March. The technology is to be provided by Alaska-based Delta Industrial Services. The center is also working with the University of Alaska to study a unique polymer-enhanced coagulation/filtration technology for cold temperature applications.
EPA, meanwhile, is still reviewing proposals to conduct arsenic treatment technology demonstration projects in 17 small communities in a dozen states as solicited last fall by the agency's National Center for Environmental Research.