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Worm Castings Central in Sludge-to-Cash Act

November 05, 1987|DENISE HAMILTON | Times Staff Writer

In science-fiction movies, giant worms gobble entire cities. In Camarillo, officials would settle for two-inch specimens that eat sewage sludge.

Like most cities across the country, Camarillo is faced with a mounting pile of sludge and dwindling options for its disposal. Landfills--where sanitation districts traditionally have chucked the stuff--are rapidly overflowing. Moreover, burning sludge or dumping chemically treated waste in the ocean raise environmental concerns.

The problem has forced many sanitation districts into exhaustive studies of alternatives. In Camarillo, officials believe the solution may lie in the belly of the lowly earthworm lumbricus rubellus.

They are experimenting with a program developed by sanitation experts in Fallbrook, a city northeast of San Diego. Officials there battle the sludge with earthworms, which eat the waste and transform it into high-nitrogen castings that can be sold as compost.

Fallbrook worms are munching on Camarillo sludge as part of a two-month experiment that will determine whether the worms can do the same for Ventura County. The results should be known by the end of December.

State sanitation officials already give the concept high marks, calling it a novel idea and an important innovation. Fallbrook is one of a small number of cities in the country--and the first in California--to dispose of sewage sludge by feeding it to worms, officials say.

"You're using the material in a beneficial way as opposed to just dumping it and land-filling it," said Bill Paznokas, an environmental specialist for the state Regional Water Quality Control Board.

The success of the Fallbrook project has made Camarillo officials bullish on vermicomposting, as the worm-farm project is officially known.

"It would be a good thing," said Fred Salinas, assistant superintendent of the Camarillo Sanitation District. "We'd be recycling it within the city. That would be good for everybody, and it would save money."

In fact, the city would save about $25,000 a year--the annual cost of depositing almost 1,000 tons of sludge in the Simi Valley landfill and trucking another 1,000 tons to Pacific Sod Farms in Camarillo.

The vermicular tale started last month, when Camarillo officials trucked about four tons of local sludge down to a remote little valley behind Fallbrook's sewage-treatment plant.

Weldon Platt, the worm wizard who runs Fallbrook's vermicomposting project, dropped some of the unsuspecting creatures into the Ventura County sludge to see if they would die or thrive. Death would have meant that the worms could not tolerate the chemicals Camarillo uses for primary treatment of its sludge. But the critters survived, an auspicious sign.

Next, Platt mixed the Camarillo sludge with wood chips, hay and straw bedding--which help soak up moisture and provide worm fodder. Then, after heating the odorous mixture for three days at 130 degrees--a health requirement for killing bacteria--he dumped it out in a long row like some nightmarish planting.

It was now time to introduce the worms. Platt unleashed thousands of hungry red earthworms on his viscous concoction, flinging them onto the pile much as a diner wields a saltshaker, he said.

That was about two weeks ago, and Platt reported cautiously last Friday that the worms appear to be thriving. With a pitchfork, he overturned some of the mixture and showed visitors a mass of wriggling worms.

"We've found that there shouldn't be any problem with the Camarillo sludge," Platt says.

But for the next 45 days, he will continue to monitor things as the worms continue to devour their environment.

Worms eat their own weight in sludge each day, Platt says. As the organic matter passes through the worms' digestive system, it is broken up and neutralized by secretions from glands near the gizzard. The castings that result are richer in nitrogen, calcium, magnesium, phosphorus and potassium than soil itself, Platt wrote in a paper describing the vermicomposting project.

The self-taught worm expert--he has a bachelor's degree in physical education from Pomona College and favors work boots, jeans and long sideburns--is an avid environmentalist, a Johnny Appleseed of worms who dreams of seeding earthworms in sludge throughout California.

He is given to philosophical meanderings on the process and is fond of citing Charles Darwin's observation that all the planet's fertile land has passed through the bodies of earthworms at least once. "It just makes such good environmental sense," he said.

If that is so, then why aren't more districts embracing this no-fuss, no-muss method of sludge disposal?

Sanitation experts say it might not be feasible in large districts like Los Angeles, whose Hyperion Treatment Plant treats about 1,100 tons of sludge per day from 3 million people. With 46,000 residents, Camarillo churns out a more manageable amount--about five tons daily.

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