Bacteria May Be Key to Cleanliness for County’s Ground Water : Pollution: As population grows, contamination becomes a bigger problem. Water scientists are looking to nature for a solution.

With Orange County’s population growing faster than its ability to import adequate supplies of water, officials are trying to harness nature’s own bacterial cleanup crews to purify valuable ground water contaminated by agriculture and industry.

The problem: The county’s 330-square-mile underground basin that supplies most of the water for 2 million residents is threatened by pollutants from both industry and agriculture.

Already more than 50 wells have been closed because they are tainted with nitrates from fertilizers or hydrocarbons from gasoline. If they could be reopened, experts say they could provide 15,000 more acre-feet of water a year, enough to quench the annual needs of 75,000 people. In addition, opening the wells would save the county about $3.5 million a year in the cost of buying water imported from the Colorado River or Northern California.

Also, county water officials are concerned about a large concentration of chlorinated hydrocarbons, once used heavily in the aerospace industry, under the El Toro Marine Corps Air Station, which could contaminate other working wells if it spreads.

The usual methods used to clean pollutants from water consist of mechanically removing them and burying the contaminants elsewhere, or flushing them to sea.

But that’s not the smartest solution, say some of Orange County’s top water scientists. Instead, they are hoping to recruit nature’s own cleanup crew: tiny bacteria already living in the underground water basin that have an appetite for those substances that poison or cause cancer in humans.

Two local organizations, the Orange County Water District and UC Irvine, are pioneering some of the nation’s leading programs aimed at developing biological techniques for decontaminating water.

Since 1985 the Orange County Water District has studied the use of microorganisms for ground water cleanup.

“It is a much more environmentally sound approach,” said Harry F. Ridgeway, principal microbiologist for the district’s Biotechnology Research Department. The district is experimenting with using bacteria to remove nitrates, gasoline hydrocarbons and trichloroethylene pollutants that reflect the area’s agricultural and industrial heritage.

Ridgeway said the bacteria consume pollutants but pose no danger to humans. But withbacteria in the water, the trick is to provide the kind of nutrients that will encourage the growth of bacteria that have a yen for the toxins targeted for annihilation.

For example, he said, bacteria that digest gasoline hydrocarbons will proliferate if they are also fed a diet of oxygen, nitrogen, phosphorous and certain other trace minerals that are pumped into the water.

Going one step further, a team of scientists led by Betty H. Olson at UCI’s School of Social Ecology has applied for a patent on a process they have developed for breeding more efficient strains of pollutant-eating bacteria than those that otherwise would exist in nature.

Olson, an environmental microbiologist, said what she is doing is “domesticating” bacteria, just as man domesticated cattle and dogs in an earlier era by breeding them for desirable characteristics. In the case of bacteria, UCI has been breeding strains that digest such pollutants as mercury and PCBs.

John Wilson, senior research biologist for the R.S. Kerr Laboratory, a facility operated by the U.S. Environmental Protection Agency in Ada, Okla., said the work being done by the Orange County Water District is remarkable because its goal is to increase the county’s water supply.

Wilson said while hundreds of laboratories across the nation are researching the use of bacteria for cleaning water, most are trying to devise methods for cleaning up particular toxic dumps.

He noted, for instance, that fertilizer was sprayed on the rocky shoreline of Alaska’s Prince William Sound to accelerate the natural bacteria cleanup of oil residue after the Exxon Valdez spill.

By contrast, Orange County is trying to develop a bacterial treatment process that is cheap and easy enough to be used on a routine basis for improving water quality.

“It is not a question of how to do it but how to do it cheaply and on a large scale,” Wilson said.

The Orange County Water District has a compelling reason for being one of the few water agencies in the country doing such research. Wilson noted that while most of the country has more water than it can use, “California is in a state of being close to water famine and future development is closely tied to the capacity to deliver adequate supplies of water.”

The recent drought has further exacerbated local concerns about potential water shortages.

For a year the Orange County Water District, in cooperation with the Navy and Stanford University, has been operating a pilot project to clean up some of the gasoline hydrocarbons in the water table beneath the Seal Beach Naval Weapons Station. Ridgeway said the scientists want to learn the least expensive diet for maintaining bacteria on the job and to identify which bacteria degrade the broadest array of hydrocarbons.

Bacteria that win the hydrocarbon-eating contest are stored at the district’s Fountain Valley headquarters with the idea of using them for future cleanup projects.

On another front, the district is studying the use of bacteria to digest nitrates, a pollutant that has seeped into the county’s ground water from fertilizers that were applied for many years by county farmers. More nitrates are being deposited in the water basin by the Santa Ana River as it empties into the county after flowing through dairy and farming regions to the north.

There are 51 wells in the county, concentrated mostly in Garden Grove and Tustin, that have been shut down because they are contaminated with nitrates.

Ridgeway said laboratory experiments show that bacteria can be prompted to convert the nitrates within the water into harmless nitrogen gas. The newly created nitrogen is expected to percolate to the ground surface and into the atmosphere, where nitrogen makes up about 80% of the air that we breath.

After the treatment, Ridgeway said, the water would immediately be pure enough for drinking.

Ridgeway’s group is also experimenting with using bacteria to purify water contaminated with chlorinated hydrocarbons, especially trichloroethylene, or TCE, widely used during World War II as an airplane engine degreasing agent and found in water near military bases including the El Toro Marine air station.

Officials hope that funding for the program will come from a grant that multimillionaire Joan Irvine Smith recently promised to promote water research.

Ridgeway said his group of researchers will have the task of selecting the most effective TCE-destroying bacteria now in existence, and then Olson’s group will work with the bacteria to produce improved genetic strains.

Ridgeway said bacteria may hold the key to more cheaply and effectively cleaning up the vast majority of contaminants.

“This is a growing and expanding technology that is just moving out of the laboratories to the field,” he said.