Seasonal Diversionary Tactics

With the help of heavy equipment, workers Monday began installing two-ton concrete blocks across Talbert Channel in Huntington Beach as part of the county’s $350,000 project to temporarily divert urban runoff into sewage treatment facilities.

As many as 2.5 million gallons of runoff a day--one of the largest diversions in Southern California--are expected to be captured by blocking the flow with “enviro-blocks” that fit together like Legos.

The project involves the Talbert and Greenville-Banning channels in Huntington Beach and the Santa Ana River, which helps drain a watershed serving tens of thousands of residents. The project is expected to be completed next week. The diversion runs through the summer.

The idea is to prevent more than 95% of contaminated runoff from going into Huntington State and city beaches, summer playgrounds for more than 6 million visitors, lifeguards said. Nearly four miles of Huntington Beach shoreline were closed in 1999, affecting merchants, tourists and surfers, after water samples at the state beach showed high bacteria counts.

Workers on Monday installed about 40 of the blocks across Talbert Channel near Yorktown Avenue between Magnolia and Bushard streets. The blocks will be covered with plastic sheeting and sandbagged to prevent leakage. Pumps will siphon the contaminated runoff into Huntington Beach’s sewer system for treatment at the Orange County Sanitation District.

Creek and channel diversions have been used for more than a decade in Los Angeles County but are relatively new in Orange County. But none in Los Angeles County have been as large, said Mark Gold, executive director for the Santa Monica-based Heal the Bay.

“The largest we have here is half a million gallons,” Gold said. “The 2.5-million-gallon diversion is very ambitious, but then they’ve had so many problems at Huntington State Beach [that] this can only help by making beaches much safer for swimming.”

Originally, Orange County had planned to install a rubber dam across both channels as a year-round solution to the runoff problem at Huntington Beach. But county officials shelved the idea after they encountered delays obtaining proper permits.

“We wanted it in place by Memorial Day,” said Kenneth R. Smith, the county’s chief engineer. “But we didn’t want to invest in the design and manufacture of a rubber dam and then not have permits.”

Instead, county officials opted for a temporary solution, one that was introduced successfully last year. The diversion was removed before winter storms struck because during heavy rains, treatment facilities cannot keep pace with storm runoff and treated waste.

Smith said permits have since been secured for the year-round dam but installation is not scheduled until next year.

Diverting runoff will ensure that it will not be a source of contamination during ocean water testing planned for the summer, Gold said. The next round of testing ocean water samples begins later this month.

The exact source of the bacteria that caused the beach closures in 1999 has never been pinpointed. Talbert Marsh, a 23-acre wildlife sanctuary for thousands of birds, was once suspected because it gets flushed by high and low tides.

UC Irvine scientist Stanley Grant has suggested that Huntington Beach’s bacterial woes are caused by partially treated sewage being drawn back to shore by a combination of internal waves, the tide and a local power plant’s cooling system, which uses 253 million gallons of ocean water a day.

Grant said the diversion projects were a step, even if temporary, in the right direction.

“Runoff contains a noxious brew of heavy metals and other pollutants,” he said. “The fact is, this is a significant diversion [of material] that none of us want to be in at the ocean and I think it’s a wise investment.”

But a spokesman for the San Clemente-based Surfrider Foundation said that while diversion projects are good, “they’re not the ultimate solution.”

“It gives a false sense of security and makes it easier for people to think the problem’s fixed and they don’t need to change their habits and watch what they put down storm drains,” John Hoskinson said. “Meanwhile, nothing is done about growth and development that brings in more people.”