PACIFIC GROVE, CA, Nov. 19, 2014 -- The WateReuse Research Foundation (WRRF) has awarded American Water (AW) (NYSE: AWK) a research grant to study the level of pathogen removal that occurs when ocean water is collected for desalination through sub-surface slant wells. The research will occur at the test slant well currently under construction in Monterey County, Calif., by the company's subsidiary, California American Water (CAW) (see "CAW test slant well approved for proposed desalination project").
Valued at approximately $330,400, with $200,000 being contributed by WRRF, "this research is important to the entire water industry," said AW's Dr. Zia Bukhari. "The effects of drought and climate change have increased interest in desalination as a technology for water supply. The science produced by this study will help define guidelines for water treatment when ocean water is collected through the environmentally preferred approach of subsurface intakes."
Slant wells, a type of subsurface intake, are drilled beneath the beach at a diagonal angle and extend under the ocean floor. These wells draw ocean water through layers of sand, thereby avoiding the impacts to marine life associated with traditional open ocean intakes. Drawing water through layers of sand also provides a first step in the purification of ocean water. The sand acts as a filter that can lessen the amount of bacteria removal required before and after the desalination process. The AW research project proposes to look specifically at the question of human pathogens (e.g., bacteria, viruses, parasites) to see what level of treatment is achieved through the slant wells and further define what steps will need to be taken in addition to reverse osmosis (RO) to ensure pathogens are removed.
"Slant wells are known for their benefits to marine life. But, they may provide an additional benefit of pathogen reduction," said CAW Director of Engineering, Rich Svindland. "If this proves to be the case, there could be significant savings in pre- and post-treatment costs for desalination projects that employ slant well technology. Because this question has yet to be studied, our findings will be extremely valuable for water resource managers and policy makers across the country."
The test well being constructed by CAW will help determine the feasibility of slant wells as a desalination intake method on California's Central Coast. CAW, which supplies water to the communities of the Monterey Peninsula, is pursuing desalination as part of a multi-sourced approach to solving the area's perennial water shortage and reducing pumping from the Carmel River. Slant wells are the favored technology of the state's permitting agencies, including the State Water Resources Control Board and the California Coastal Commission.
Accordingly, the Monterey Bay National Marine Sanctuary and the National Oceanic and Atmospheric Administration have issued guidelines for desalination projects within the sanctuary that direct any project proponent to pursue subsurface intakes where feasible. CAW recently received a $1-million grant from the California Department of Water Resources to help fund the installation of the test well. The research project team will consist of Bukhari as the principal investigator, with AW's Dr. Patrick K. Jjemba and Elaine Howe of Trussell Technologies as co-principal investigators.
For more information on the desalination project, visit www.watersupplyproject.org.
See also:
"CA desalination slant wells prove promising in collecting seawater"
"CA borehole investigation shows positive results for desalination project"
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