Toxic waste disposal industry devising alternatives to landfills
Out of the toxic muck made in much modern manufacturing, a new industry is beginning to sprout. Dumping hazardous industrial wastes in the ground is still the most common method of disposal, but there is a budding forest of potentially more wholesome alternatives.
None of the options are as cheap and all-purpose as landfills have been. But then, some of the ''economies'' have been false ones, as the expensive Love Canal debacle pointed up.
''Landfill is coming more and more under attack both by regulation and economics,'' says Doug Shooter, a hazardous-wastes specialist at Arthur D. Little Inc., a consulting firm.
Public distaste for toxic landfills is so strong that no new sites have been allowed for five years. Southern California now has only one active site; New England, none.
The leading option is incineration. About 10 percent of the hazardous wastes now produced in the country are burned, Dr. Shooter says. Various incinerator innovations have made it possible to burn almost any organic waste. Some companies are developing ways to recover heat from the process as a way of cutting costs.
The Environmental Protection Agency demands that hazardous-waste incinerators burn 99.99 percent clean - a standard known in the industry as ''four nines,'' which takes the most advanced and expensive equipment to meet. Even with this standard, some environmentalists are still concerned about emissions from these incinerators.
Especially dangerous chemicals are sometimes burned at sea, where air emission standards are looser. Chemical Waste Management, the largest company in the industry, has just floated a second incinerator ship, Vulcanus II. Its first ship, Vulcanus I, stirred protests along the Texas coast when it burned PCB-contaminated wastes in the Gulf of Mexico more than a year ago. At least two more ships are under construction for other companies. The ships, too, are under EPA as well as international maritime regulation, but their operations are hard to monitor.
Another alternative for waste treatment is oxidation. Modar Inc., in Natick, Mass., is testing a system that heats and squeezes water into a supercritical state. When oxygen enters the reactor, organic compounds disintegrate within a minute, leaving carbon dioxide and water. Zimpro Inc. of Rothschild, Wis., is installing a simpler but probably less thorough oxidation system at the Casmalia landfill in Santa Barbara, Calif., which aerates a heated waste stream to break it down.
Like incineration, oxidation will work on most organic wastes. These systems are expensive to build, says Dr. Shooter, but efficient to run. The cost of a system like Modar's, he says, is within the range of economically viable technologies.
There are also bacteria that eat hazardous organic wastes. Some of the microscopic bugs found in nature eat solvents and pesticides as noxious as DDT. Gene-splicers are developing ''superbugs'' to munch up even nastier sludges.
Inorganic wastes - mostly acids and heavy metals - are tougher to deal with. An important step is separating the solids from the acids. The solids are then relatively safe to put in landfills, says Kent Stoddard of California's Department of Health Services, and the liquids remaining are often clean enough to run through the sewer system.
The object is to keep the waste from leaching into the ground. One way is to mix the waste with cement to solidify it. It can also be dried and mixed with hot plastic, which then cools and solidifies.
In many cases, it is actually cheaper for companies to treat their hazardous wastes, rather than just dispose of them.
A New England manufacturer of computer disks, for example, uses about 8,000 gallons a month of a flammable solvent and needs to get rid of it. The nearest legal toxic-waste landfill is in Buffalo, N.Y.
Instead, Union Chemical Company in Maine treats the stuff and returns 5,000 gallons a month of pure solvent to the company. It incinerates the remaining 3, 000 gallons of muck, producing steam in the process which Union Chemical uses to power its plant.
What the disk manufacturer saves by reclaiming most of its solvent, according to Union president Raymond Esposito, is more than enough to pay for treatment.
''It shouldn't have taken an RCRA to get people to do this,'' Dr. Esposito says. The RCRA, the federal Resource Conservation and Recovery Act, is the legislation that sets standards for the handling of hazardous wastes.