Calif. accepts progressive biological process for perchlorate removal

Advanced technology from Carollo Engineers removes munitions, rocket fuel and fireworks component to below detection from contaminated drinking water. First of its kind to be accepted by California Department of Health Services for this application...

FOUNTAIN VALLEY, CA, March 23, 2005 -- Carollo Engineers was granted conditional acceptance by the California Department of Health Services (DHS) for a "Fixed-Bed Biological Treatment" process for the production of drinking water from perchlorate contaminated water. Acceptance of the company's biological treatment process is the first approval of its kind for a non-proprietary perchlorate treatment technology and now makes it possible to implement such a treatment process in California.

The fixed-bed biological process has key features that make it an attractive perchlorate removal technology. Specifically, this technology:
-- Does not produce a perchlorate-laden waste stream like other technologies such as membranes and ion exchange.
-- Removes perchlorate to below detection (<1um/L) by converting it to innocuous chloride and oxygen. The result is high process efficiency with water recoveries greater than 97%.
-- Reduces perchlorate to below detection regardless of raw water perchlorate concentration. Thus, the pending maximum contaminant level (MCL), action level or proposed no adverse health-effects level will not impact the design or operation of this process.
-- In addition to perchlorate, eliminates other contaminants simultaneously, including, nitrate, organic matter, and taste and odor compounds.
-- Costs less to operate than conventional perchlorate removal technologies.

In a letter of conditional acceptance, DHS stated that it accepts fixed bed biological treatment to remove or reduce perchlorate from source water(s) that might be used for potable supply. The acceptance was subject to certain conditions including careful monitoring and control of perchlorate concentration, flow and acetic acid feed.

"Comparable technology has operated successfully in Europe to remove nitrate from drinking water for more than twenty years," said Carollo Engineers' Dr. Jess Brown, project manager for biological treatment. "When coupled with the overwhelmingly successful outcome of recent fixed-bed pilot studies, it is evident that biological treatment is a feasible, effective, and sustainable process for removing perchlorate from drinking water."

Application for approval of the fixed-bed biological treatment process stemmed from a six-month pilot study at the Castaic Lake Water Agency (CLWA) in Santa Clarita, Calif. The treatment process was selected for testing because it cost effectively removes perchlorate from groundwater without creating a waste stream that requires further treatment or disposal.

Carollo Engineers P.C. (www.carollo.com) is a leader in water and wastewater planning, design and construction management. Founded in 1933 and with headquarters in Fountain Valley, Calif., the environmental engineering firm has successfully completed more than 15,000 public sector projects and is highly respected for its attention to client service and commitment to quality. Ranked as one of the nation's top consultants by Engineering News Record and as the largest firm dedicated exclusively to water and wastewater treatment services, it maintains 24 offices in 12 states.

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