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'Bio-Slime,' the Latest Theory on Pollution, Oozes Intrigue

Do bacteria that closed shoreline in 1999 grow in storm drains? Baffled scientists are willing to explore idea.

October 05, 2003|Jean O. Pasco and Dan Weikel | Times Staff Writers

After spending four years and $25 million, researchers still can't explain how waters off Huntington Beach became so contaminated in 1999 that miles of shoreline had to be closed during the height of the summer tourist season.

Today, several theories intrigue water-quality researchers about the mysterious bacteria spikes, which have subsided but haven't completely vanished.

One untested theory has a name more suited to a low-budget horror flick: "bio-slime."

The theory holds that some storm drains carrying urban runoff provide dark, nutrient-rich environments where bacteria gather and grow, further contaminating pools of water before being flushed into the ocean. Bacteria can also flourish in beach sand before being pulled back into the water at high tide.

Since 1999, government and private researchers have turned Huntington Beach into one of the most studied stretches of coastline in the nation, as they seek to explain the rash of closures that emptied beaches, ruined the summer for local merchants and cost the city millions in tourist dollars.

Ken Theisen, a staff scientist for the Santa Ana Regional Water Quality Control Board in Riverside, said the fruitless effort to find the cause of the contamination is "the hardest thing I've worked on in 20 years."

"You keep scratching your head and trying to figure out what is causing this," he said.

With dye markers, test kits and computers, researchers have checked sewer systems, water treatment facilities, coastal construction sites and an outfall pipe from the Orange County Sanitation District that pumps 234 million gallons of treated wastewater into the ocean daily.

All have been eliminated as the cause of the 1999 beach closures, which were in effect from July 1 to Labor Day weekend. As the summer wore on, the length of shoreline closed to swimming peaked at about 4.5 miles.

"Huntington Beach and Newport Beach are ground zero for these efforts," said Stanley B. Grant, professor of environmental engineering and chairman of the department of chemical engineering and materials science at UC Irvine.

Grant conducted several studies on the bacteria problem, including an examination of the bacterial flushing from Talbert Marsh, a reclaimed wetlands area along Pacific Coast Highway in Huntington Beach that drains into the ocean. "We know there is no natural source," he said. "Weird things happen and you don't understand why."

In a study released in August, the holding basins, sewer lines and cooling system of the AES power plant in Huntington Beach were also ruled out as major contributors of bacteria. Only small amounts of bacteria exist in the warm water that the plant discharges into the ocean, the study -- paid for by AES -- found.

Most scientists and regulators now agree the main culprit is urban runoff, water from hoses and sprinklers that collects a toxic brew of pesticides, fertilizer, road grime, oil and pet waste as it washes down curbside drains. But that isn't the only source.

New theories have emerged, including the existence of bio-slime, the flow of bacteria-rich waters from the marsh and the possibility that urban runoff from the Santa Ana River doubles back toward shore rather than being swept out to sea.

Weather, tides, ocean currents and water discharged from the AES plant also might play a role, researchers say. The heated water from AES might pick up bacteria already at sea and carry it back into swimming and surfing zones.

Testing results collected for decades by the Orange County Health Department, in fact, show bacteria rising sharply at certain parts of the Huntington Beach shoreline during intense tidal surges. One paper by Grant indicated water quality off Huntington Beach, though it has experienced cyclical bacteria "events," is cleaner now than it was 40 years ago.

The elusive problem has led regulators to suggest a sweeping and costly solution to the problem: diverting all urban runoff, except during storms, into sewer systems for treatment.

Huntington Beach already sends about 2 million gallons a day from its storm drain system to the Orange County Sanitation District. An additional 500,000 gallons arrives from Newport Beach and Crystal Cove. The diversion led to a drop in bacteria counts along key stretches of Huntington Beach, leading the city to request diversion from five additional catch basins. Now the vast majority of dry season runoff that had been flowing into the Santa Ana River has been diverted, including runoff from cities upstream.

But there's a limit to what the district can handle. Sanitation district officials said the most they can accept -- or afford -- at their cleansing ponds is 4 million gallons a day, a fraction of the 100 million gallons of tainted water that flows daily down county rivers, creeks and streams to the ocean.

"If there is no other way to deal with it, we will try to do it, but it has to be a significant problem," said Robert P. Ghirelli, the district's director of technical services.

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