Bacteria’s Dirty Little War Against Toxics : Bioremediation: Highly touted microbes have wide menu of waste they can eat. But new industry has its critics.
R.B. (Jones) Grubbs is a New Age Mr. Clean.
Instead of killing germs, however, Grubbs supplies them: bacteria to dissolve grease, tar, and sludge; bacteria to control odors at smelly food factories; and now, bacteria that eat toxic waste.
Some of Grubbs’ bugs--short for “bacteria under guidance and supervision”--will munch their way through garden-variety gasoline spills. Others will digest crude oil, diesel, coal tar, industrial solvents, chemicals used in antifreeze, and a wide array of other unpleasant gunk, breaking it down into carbon dioxide, water and benign organic compounds.
“When I first got into the business and I told people what I did, they wanted to wash their hands,” Grubbs said. “ ‘ Bacteria? What’s he spreading?’ ”
Now, he’s hailed at cocktail parties as an environmental hero, and his biotechnology company, Solmar Corp. of Orange, sold $1.5 million worth of bacteria last year. About 40% of the bugs were put to work cleaning up contaminated soil or water.
Grubbs is part of a fledgling industry called bioremediation, which uses microbes to decay, detoxify or prevent the creation of hazardous waste. Though not an environmental panacea, proponents say, bioremediation can be a safer--and much cheaper--method for dealing with some of America’s most pervasive pollution problems.
Oil companies have known for years that dumping garden fertilizer on petroleum spills stimulates the bacteria living in the soil to break down the waste.
But bioremediation got its big break during the Exxon Valdez oil spill of 1989, when nutrients added to 74 miles of oil-smeared shoreline in Prince William Sound helped marine microorganisms break down the oil much faster than in untreated areas, and with no ill-effects, according to the Environmental Protection Agency.
Last year, commercial bioremediation projects generated revenues of $20 million to $50 million, according to Thomas G. Zitrides, president of the Washington-based Applied BioTreatment Assn., a 62-member trade group founded two years ago. The group estimates that its market will reach $200 million a year by 1996, Zitrides said. Others say sales are much higher. Grant Ferrier, editor of the Environmental Business Journal in San Diego, puts 1990 bioremediation sales at $80 million to $100 million.
Whatever its size, the new industry has powerful patrons. Chief among them is EPA Administrator William K. Reilly, who recently described himself as “a flag-waver” for biotechnology and bioremediation.
Encouraged by the success of the Valdez cleanup, the EPA will spend $14 million on bioremediation research and development next year. Four years ago, bioremediation wasn’t even a budget item. The agency is also encouraging private research, attempting to streamline regulatory procedures and sponsoring a variety of demonstration projects.
“We’re interested in pushing it on every front we can,” said Erich Bretthauer, EPA assistant administrator for research and development.
Bretthauer said bioremediation is “an area that offers tremendous potential for dramatically reducing the cost of cleanups for some organic chemicals, and it hasn’t had a loud (advocacy) group out there, like some companies that build incinerators or other things to deal with waste.”
The technology still faces skepticism from regulators, clients and even environmentalists. Although bioremediation is generally accepted for cleaning up petroleum contamination in soil, it does not work for all applications, and has yet to win acceptance as a way of handling more toxic chemicals.
Moreover, the EPA, many large environmental cleanup firms and some environmental groups say that the best bioremediation projects employ the microbes that already live at the contaminated site. Some are suspicious of adding bacteria--even naturally occurring ones--to a site where they are not native.
“I get concerned about some of the hype that surrounds bioremediation,” said Rebecca J. Goldburg, a biologist with the Environmental Defense Fund. “Getting microbes to break down chemical compounds isn’t like getting cats to catch mice.”
For soil treatment, the main drawback to bioremediation is that it requires open space on which to treat the contaminated dirt, and time for the bacteria to work--sometimes a year or more, depending on the concentration of pollutants.
Moreover, the bugs may become bored with eating waste once the contaminants reach a relatively low level, and switch to a food supply that is more plentiful or easier to digest. “Will a kid eat spinach in a chocolate shop?” Grubbs asked. In some cases, bacteria have been unable to reduce pollutants to low enough levels to meet stringent environmental regulations.
But bug-handlers are developing new methods for thwarting this foible as they master the microbiology of degradation. Among other things, they have developed a variety of chemicals called inducers that essentially act as appetite stimulants.
Despite these limitations, bioremediation has been successful at hundreds of sites nationwide, including oil fields and refineries, diesel and gasoline spills, and leaking underground storage tanks, regulators said.
It has also been shown to work on wood preservatives, herbicides and solvents, and is being used at 22 federal Superfund toxic-waste sites, according to the EPA.
“The technology is here,” said UC Irvine microbial ecologist Dele Ogunseitan, who experiments with inducers. “The question is how to commercialize it and make it a permanent fixture in industry.”
Environmental cleanup companies are also beginning to use microbes to degrade more chemically complex--and more hazardous--pollutants. These include toxic PCBs (polychlorinated phenols), pesticides, dioxin and TCEs (trichloroethylenes), which are major threats to ground water.
Meanwhile, some scientists are also using advanced techniques such as gene splicing and gene amplification to produce strains of bacteria that they hope will be more effective and more versatile than natural ones. At least one genetically engineered, TCE-eating microbe has already been patented, though it is unclear whether the EPA will allow it to be used.
Grubbs and most of his competitors, however, are sticking to natural bugs. Most of their jobs are the result of leaking underground storage tanks at gas stations, oil refineries and factories.
Grubbs says his biggest challenge is identifying customers, as most potential clients don’t want to advertise their waste problems.
“Your biggest marketing problem is you’ve got a cure for VD and nobody wants to admit they have it,” Grubbs said.
The 53-year-old chemical engineer is a jolly fellow who can cheerfully discuss the microbiology of sewers while devouring a large chicken-and-pasta lunch. He holds forth about the merits of various bug concoctions with the gusto of a vintner discussing fermentation.
A good bug, says Grubbs, is hard to find.
While many bacteria can be made to tap dance in a test tube, to prevail in the field a bug must be able to compete successfully with other microbes. It shouldn’t produce nasty byproducts like hydrogen sulfide, which smells like rotten eggs. Above all, it must not cause disease.
One of Grubbs’ most precious bugs was isolated from a pile of hog manure. “It was turning that hog manure into peat moss,” he said admiringly. Other waste-eating bugs hail from toxic lagoons and old oil sumps.
But some stuff proves toxic even to toxic waste-eating bacteria. Chromium and disinfectants like chlorine and iodine will kill them.
“The first thing we do is go in and get a sample, and say, ‘Can the bugs live with this stuff?’ ” Grubbs said. If they turn up their toes, he tells the customer to call a company that can encapsulate, heat-treat or incinerate the waste. “We don’t have a magic bullet,” he said.
Many of the largest environmental cleanup companies, however, say there is usually no need to add bacteria at all. Instead, they aerate the contaminated soil, add water and fertilizer, and wait.
“Take a gram of soil, which weighs about as much as a dime, from your garden. You’ll probably find about a million microorganisms there. . . .” said Dennis Dineen, chief scientist at McLaren-Hart Environmental Engineering in Irvine, which has cleaned up 18 contaminated sites without adding outside bugs. “Say 1% of these are able to eat oil as a carbon source. The ones that can eat oil have an advantage, and they take over. . . .
“Jones Grubbs is making a lot of money selling them, but you don’t need them,” Dineen said. No scientific studies have ever been conducted to compare results using bacteria supplied by Grubbs and competitors to those obtained with on-site bacteria, he said.
Moreover, bioremediation tends to meet with less public resistance when no “outside” bugs are added, companies said.
“Before I got involved in this stuff, I thought, ‘Whoa, we’re messing with nature, and mutants are going to grow, and you’re going to get the Thing That Ate Los Angeles,’ ” said James J. King, who handles biotechnology applications for the Torrance-based International Technology Corp., widely known as IT. “That’s so far from the truth. We’re using the stuff that’s already there.”
IT has completed 14 cleanups to the satisfaction of state or federal regulators, and is now working on 50 more. Like its competitors, the firm hopes to land government work cleaning up polluted military bases and weapons-production sites.
Bioremediation accounted for about $10 million of IT’s fiscal 1991 sales of $407 million, King said, and the company expects its bioremediation business to grow 15% to 30% a year.
While bioremediation is now often cheaper than other cleanup methods, it is likely to become even more attractive as landfill space gets scarcer. Including the cost of digging up and aerating the dirt, bioremediation typically runs $10 to $80 per cubic yard of contaminated soil, compared to $122 to $810 to excavate it, haul it to a landfill or incinerate it, according to a report by the National Governors’ Assn.
In Southern California, the costs typically range from $15 to $50 peryard, roughly three to five times cheaper than landfill, said Jim Ross, senior engineer for the Los Angeles region of the California Regional Water Quality Control Board.
In Santa Fe Springs, for example, a real estate developer, McGranahan Carlson Co., wanted to build a $100-million industrial park on a dwindling oil field. But first, it had to clean up 75 acres of oily soil and contaminated sumps.
One environmental consultant advised the developer to dig up the soil and haul it to a certified landfill, at an estimated cost of $25 million, McGranahan partner Grant B. Cooper said. Instead, Cooper said, they fired the consultant, hired McLaren-Hart, and opted for bioremediation. Cost of the 18-month cleanup: about $1.1 million.
Engineers scaped away 1 to 4 feet of the dirty topsoil, about 65,000 cubic yards in all. They stacked it up 7 feet high on 7 acres set aside for treatment, scraped off the topsoil as the bacteria cleansed it, and returned the purified soil to the site.
“When it’s done, it’s just regular dirt,” Cooper said. “It has no smell. It’s just like the dirt in your garden. . . . I have a whole new appreciation for clean dirt now.”
Unocal Corp. has used bioremediation at “dozens” of sites throughout the company, with more mixed results, said Ross A. Denton, the firm’s environmental programs manager. A 16-month cleanup at an abandoned fuel-storage reservoir in Torrance went smoothly, Denton said, but a Seattle project bogged down after the environmental contractors, who had bargained on treating only gasoline and diesel contamination, suddenly uncovered a cache of old lube oil.
“It was a heavier product than we thought, and it didn’t degrade nearly as fast in the (cold, rainy) climate as we thought,” Denton said.
The consultants are still trying to decide whether to heat-treat the waste or haul the dirty soil away. In the future, Denton said, the company will want “good, careful assessment” before opting for bioremediation.
So far, California regulators have been reluctant to allow bacteria to be used on hazardous chemicals like TCEs, PCBs and vinyl chlorides, although other states are trying it.
“For gasoline and diesel fuel, it works very well,” said Joshua M. Workman, senior water resource control engineer for the Regional Water Quality Control Board in Los Angeles. “For chlorinated hydrocarbons and these other organics, the jury is still out.”
How Bioremediation Works
Bioremediation uses naturally occurring bacteria to degrade pollutants in soil, water and air. Sometimes bacteria or nutrients are added directly to the contaminated site. In other cases, the contaminated soil or water is removed, treated in a tank called a bioreactor, and returned to the site when clean.
Above-Ground Treatment: Contaminated water is pumped out of an underground aquifer and treated with waste-eating bacteria in a bioreactor. The bacteria are filtered out, and the clean water is returned to the ground.
Injection Treatment: Waste-eating bacteria and nutrients are injected directly into the contaminated aquifer. In other cases, only nutrients that stimulated existing bacteria are injected. When the treatment is stopped, the bacteria die.
Soil Remediation: Contaminated soil is removed and aerated. Nutrients are added to stimulate the natural soil bacteria, and sometimes both nutrients and bacteria are added. This technique works best on petroleum contamination.
Pollutants That Can Be Degraded
Bacteria can degrade these compounds with relative ease:
Petroleum products: gasoline, diesel, fuel oil
Hazardous crude oil components: benzene, toluene, xylene, naphthalene
Some polynuclear aromatics: benzo(a)pyrene, a carcinogen found in coal tar, oil and charcoal.
Some pesticides: malathion
Coal compounds: phenols and cyanide in coal tars and coke waste.
Some industrial solvents: acetone.
Other: ethers; simple alcohols such as methanol, and other ground-water contaminants including methylethylketone; ethylene glycol, an ingredient in antifreeze, often found at airports.
Partially Degradable Pollutants
These are chemicals that are difficult to degrade, or wastes that are so mixed and variable that they degrade at different rates and may leave some toxic chemicals behind.
TCE (trichloroethylene): a major threat to ground water; it has been degraded in pilot tests but never in full-scale cleanups.
PCE (perchloroethylene): a dry-cleaning solvent; it degrades to TCE when no oxygen is present.
Wood preservatives, including pentachlorophenol, and other ingredients in coal tar: can be degraded but only under carefully controlled conditions.
PCBs and dioxins: have been degraded in the laboratory but not in the field.
Arsenic, chromium and selenium: Bacteria have been used to stabilize these poisonous compounds in pilot tests, but the technology is still being developed.
Heavy metals are not biodegradable, but bacteria can concentrate them into forms that make them more easily disposable.
Uranium: A strain of iron-eating bacteria can be used to extract the low-level radioactive waste from water.
Mercury: Poisonous as an element and as a salt, but scientists are experimenting with using bacteria to stabilize it in a safer form.
DDT: The now-banned pesticide can be degraded, but with difficulty.
Source: U.S. Environmental Protection Agency, California Institute of Technology