Reality Check : Down the...

In the late 1970s, the U.S. government offered local sanitation officials a deal that would have made Rumpelstiltskin smile.

If they would try out a new technology that promised to turn sewage into valuable electricity, the Feds would foot most of the multimillion-dollar bill.

The process, originally designed to extract vitamins from fish livers, had never been used in a major sewage plant. But Los Angeles City Hall and the separate county sanitation agency signed up anyway, convinced that the costly gamble was worth the risks.

It was a bad bet. Like the king’s bride who used the dwarf’s magic to spin straw into gold at a terrible price, city and county sanitation officials discovered that the federal government’s deal was no bargain.

Instead, the experiment has turned into a lesson on the pitfalls of rushing to embrace a new technology, even one that promised to turn an urban byproduct into a municipal virtue.

There was no shortage of raw material. Each day, nearly a billion gallons of sewage--equal to the amount of wine consumed annually in the United States--flow into the county and city treatment plants.

The obstacle was in refining a complicated, possibly audacious, process to convert raw sewage--which is 99% water--into a combustible powder that when burned would produce steam to spin power-generating turbines.

After a decade of struggling to make the technology work at its Hyperion treatment plant near Los Angeles International Airport, the city decided in February to scrap a major component of the system and go with something simpler.

And the Sanitation Districts of Los Angeles County, which rushed headlong to design its own version of the system before the city had worked out the kinks, never even fired up their $166-million Carson plant. They are planning to dismantle it and sell off the parts to the highest bidder.

“It was obvious there were problems, but [sanitation officials] were rolling the dice,” said Los Angeles County Supervisor Zev Yaroslavsky, an early critic of the city’s system as a member of the City Council. “But when you’re spending the taxpayers’ money, you don’t have the right to go hog-wild . . . in a technological crap game.”

At the time, few questioned the wisdom of gambling hundreds of millions on an unproven idea.

It was the middle of the second Arab oil embargo and gasoline prices were spiraling skyward. The rising cost of gas was worrisome to county sanitation officials, who had been trucking sludge, or processed sewage, to landfills.

At the same time, the U.S. Environmental Protection Agency was suing the city of Los Angeles for dumping its sludge into Santa Monica Bay in violation of the Clean Water Act.

An EPA-funded study encouraged the new technology, which promised to end complaints about smelly sludge trucks, save gas and clean up the ocean. The huge treatment plants would also operate on self-made power. Best of all, federal and state agencies would pay 97% of the construction costs.

The city, which was under a court-ordered deadline to stop dumping sludge by mid-1985, pushed ahead with construction plans for the $160-million Hyperion Energy Recovery System. The county followed with its own version.

Problems surfaced early at the city’s plant. Sludge was more abrasive than anyone anticipated, wearing out pipes and valves. Fires erupted in the machinery where the volatile sludge was dried using a technology called the Carver-Greenfield process. By the time the project was finished three years past deadline, construction costs had soared to $260 million.

Troubles with the untested drying process--which had cost about $50 million to build, more than twice the original estimate--meant that the system could only handle about one-fifth of the sludge it was designed for. In February, six years after the system began daily--albeit slow--operation, engineers decided to abandon the Carver-Greenfield process and go with a more proven steam-based technology.

Despite the city’s troubles, the county continued to build its sewage-to-electricity system. By the time construction finished in 1992, officials had decided that the plant was too inefficient and expensive to run.

The Carver-Greenfield portion of the Carson plant never dried an ounce of sludge. It sat idle except for serving as a movie set for Steven Seagal’s movie “On Deadly Ground.”

Now the federal government is offering a new deal. If county officials agree not to seek grants to fix the failed technology, the EPA promises not to force the county to use the system.

County officials will keep the storage tanks and conveyor belts, but they hope to sell the combustion system, drying mechanism and steam turbines--even at salvage prices.

In retrospect, local and federal officials say they wish they had not moved so quickly to embrace a speculative technology. They say it was foolish to build two systems in Los Angeles County simultaneously before the bugs had been worked out.

As it turned out, the oil crisis ended and gasoline prices came down. And the technology for processing sludge improved so much that farmers are now buying the waste and adding it to soil used to grow hay and cotton. Nurseries and home centers are selling composted Hyperion sludge and yard trimmings as TOPGRO soil amendment.

“It’s so easy to sit here today knowing what we do and say, ‘Geez, it was a mistake,’ ” said James Stahl, assistant chief engineer for the Sanitation Districts of Los Angeles County. “But it was an idea that was right for the times.”

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The Process: Turning Sewage Into Power

At the Hyperion Sewage Treatment Plant near LAX, technology to convert sludge into electricity-while cleaning up Santa Monica Bay-cost millions but failed to work as promised.The weak link was an untested process to dry the sewage-which is mostly water-so it can be burned efficiently. The Carver-Greenfield process, a sludge drying system often used in oil refineries, was promoted as a solution to urban sewage woes in the 1970s but is being abandoned.

Sewage Treatment

Sewage is brought into the plant, where sludge is separated from the liquids, placed in anaerobic digestors and fermented for 20 days. Resulting effluent is spun in a centrifuge to remove excess water, leaving a volatile organic material called “wet cake.”

Problems

* The sludge proved to be far more abrasive than engineers predicted, eating through valves and seals, sometimes in a matter of hours.

* Severe clogging occurred when the partially dried sludge turned into paste, an unexpected phenomenon the engineers call the “gummy phase.”

* Hair and grit carried into the system in the sludge became tangled in the intricate machinery, forcing engineers to install “muffin monsters,” powerful steel jaws that pulverized the sludge.

* The highly volatile sludge mixture would sometimes catch fire, often after getting stuck in the pipes. Because it burns extremely hot, fires cannot be extinguished by conventional means. The only hope is to cool down the system with steam, a process that can take several days.

The Carver-Greenfield Process

The heart of the Carver-Greenfield process involves adding a highly flammable commercial oil to the wet cake and moving the sludge mixture through a drying process to eliminate all remaining moisture.

* Oil added to the wet cake keeps the sludge in a fluid state.

* Evaporation of the water leaves a mixture of oil and sludge solids.

* The de-watered mixture is spun again and heated, separating the solids and the oil. The oil is removed and reused.

* A highly combustible, bone-dry gray powder--the consistency of flour, high in organic content and smelling of oil--is all that remains. It is then burned as fuel in boilers to create steam and drive electricity-generated turbines.

Sources: Los Angeles Bureau of Sanitation, Times files; Researched by NONA YATES / Los Angeles Times