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O.C. Moves to Clean Its Sludge

Sanitation: The costly process is aimed at making the waste acceptable to counties that have stopped taking it or plan to.


As farming counties start shutting the doors to Orange County's exported sewage sludge, local planners are counting on making the solid gunk cleaner, a process expected to carry a price tag of eight figures.

But just in case, they're keeping open the option of just shipping the stuff off to Arizona.

At a meeting this week, staff for the Orange County Sanitation District laid out their situation to a district committee: Riverside County stopped taking the county's sludge over the summer. Two counties in the Central Valley will stop in 2003. Cleaning up the sludge to the point where those three counties would continue accepting it would cost tens of millions of dollars. But so would trucking it all the way to another state.

"It's not an option not to take some kind of action," said district spokeswoman Lisa Lawson. "We have to find other places that will accept [the sludge] or look at options for treating it."

The district treats waste water from the toilets, sinks, showers and dishwashers of more than 2 million residents of north and central Orange County. Its plants in Fountain Valley and Huntington Beach separate the liquid from the solids--the sludge. The sludge is treated to remove some bacteria, viruses and volatile organic compounds; more water is removed. At that point it's a "Class B biosolid," which means it still contains many pathogens.

The resulting 200,000 wet tons a year, 541 wet tons a day, of coal-black gunk is trucked to farms. (A wet ton is about 500 pounds.) The sanitation district relies on the agriculture industry to use the sludge to fertilize nonfood crops such as alfalfa and cotton.

None of the sludge is used in Orange County, because there is little farmland. Most sanitation agencies, including those for the county and city of Los Angeles, have relied on farmers in Kern County and the rest of the Central Valley.

Orange County officials also had relied heavily on Riverside County, sending nearly half their sludge there. But this summer, Riverside officials voted to ban Class B sludge use for health and aesthetic reasons (it has a foul odor), making it one of at least 19 counties in the state to restrict or ban Southern California's mountainous stockpile of human waste.

The local district is not alone in scrambling to find new solutions. The city of Los Angeles is seeking federal permission to inject treated sludge into a nearly depleted oil and gas reservoir a mile underground at Terminal Island in Los Angeles Harbor.

The Orange County district still sends sludge to San Diego, Kern and Kings counties.

However, Kings and Kern have passed ordinances banning the importation of Class B sludge starting in 2003. And San Diego County says it has too little farmland to take any more than it already does.

As a result, district officials are moving toward treating the sludge so that it qualifies as "Class A," by removing more disease-causing bacteria, viruses and toxic metals. Such treatment is expensive and eventually would result in rate increases for customers.

That extra treatment can be done by composting, chemical stabilization or heat drying. The local district is looking at the first two options, since heat drying is expensive and the resulting ash would create another disposal problem.

Another proposal discussed Wednesday involves buying land in Colton so that Inland Composting and Organic Recycling could turn the sludge into compost, which is still acceptable to many counties.

Land acquisition and other capital costs would be $43 million to $68 million. It would cost $22 per wet ton to treat the sludge. The district expects to send 300 wet tons a day to the facility starting in mid-2003.

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