Ozone disinfection facility to protect Dana Point beaches

Salt Creek and nearby beaches were closed or posted with health advisories due to bacterial levels on more than 1,600 days in 2002.

Encinitas, CA, Oct. 8, 2003 -- Salt Creek and nearby beaches were closed or posted with health advisories due to bacterial levels on more than 1,600 days in 2002.

To keep its fabled beaches open and free of harmful bacteria, the City of Dana Point, California, will soon build a $4-million stormwater treatment facility - one of the first of its kind - that uses ozone to treat urban runoff.

The new facility will filter urban runoff from Salt Creek, then treat it with ozone in a below-grade concrete basin before releasing the treated water into the ocean. The process uses ozone to oxidize contaminates in the water.

The 2,000-square-feet stormwater treatment facility was designed by one of the nation's top engineering firms, PBS&J, and funded by Proposition 40 Clean Beaches Initiative Grant funds. PBS&J engineer and acting Deputy City Engineer Matthew Sinacori was instrumental in obtaining grant funding for the entire cost of the facility.

The City of Dana Point has implemented one of the most aggressive and comprehensive urban runoff programs in Southern California. "We believe that the City received these grant moneys because we are perceived as a leader in water quality issues," said City Manager Doug Chotkevys. "Water quality is a top priority in the City's strategic plan. I am excited that the State Water Resources Control Board has taken this opportunity to identify the Salt Creek Project as one of the showcase projects for the first funding round in the entire state."

The disinfection facility will be constructed near Salt Creek, adjacent to an existing sewer pump station. When completed, the facility will treat up to 1,000 gallons of water per minute of dry-season runoff from Salt Creek. Instrumentation and monitoring will accommodate variations in water quality, and Operations staff will be able to adjust treatment levels whenever necessary.

Why Ozone?

"Since Salt Creek's typical dry season flow is about 1,000-gallons-per-minute, it was not feasible to use a system involving diversion and treatment in a sanitary system," said PBS&J Project Manager Jim Rasmus, P.E., DEE.

"Because of safety concerns, we also discounted disinfection using chlorination. That left us a choice of using ozone or an ultraviolet light system. Ozone was eventually selected over ultraviolet light based on levels of iron, hardness, suspended solids, dissolved organics, UV transmission, and other parameters that affect the costs and operation of the facility.

PBS&J (www.pbsj.com) is a provider of infrastructure planning, engineering, construction management, and program management services. The employee-owned firm is ranked by Engineering News-Record as 25th among the nation's top engineering consulting firms. PBS&J has 3,300 employees and 60 offices located throughout the U.S. and overseas.

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