Lindane in our wastewater
THE SLUDGE HITS THE FAN
Secret Ingredients
The HarperCollins Dictionary of Environmental Science
defines sludge as a "viscous, semisolid mixture of bacteria- and
virus-laden organic matter, toxic metals, synthetic organic chemicals, and
settled solids removed from domestic and industrial waste water at a sewage
treatment plant."
Over 60,000 toxic substances and chemical compounds can be found in sewage
sludge, and scientists are developing 700 to 1,000 new chemicals per year.
Stephen Lester of the Citizens Clearinghouse for Hazardous Wastes has compiled
information from researchers at Cornell University and the American Society of
Civil Engineers showing that sludge typically contains the following toxins:
Polychlorinated Biphenyls (PCBs);
Chlorinated pesticides -- DDT, dieldrin, aldrin, endrin,
chlordane, heptachlor, lindane, mirex, kepone, 2,4,5-T, 2,4-D;
Chlorinated compounds such as dioxins;
Polynuclear aromatic hydrocarbons;
Heavy metals -- arsenic, cadmium, chromium, lead,
mercury;
Bacteria, viruses, protozoa, parasitic worms, fungi; and
Miscellaneous -- asbestos, petroleum products, industrial
solvents.
In addition, a 1994 investigation by the US General Accounting
Office found that "the full extent of the radioactive contamination of
sewage sludge, ash and related by-products nationwide is unknown." Most of
the radioactive material is flushed down the drain by hospitals, businesses and
decontamination laundries, a practice which has contaminated at least nine
sewage plants in the past decade.
In 1977, EPA Administrator Douglas Costle estimated that by 1990
treatment plants would be generating 10 million tons of sludge per year, a
thought that "gives us all a massive environmental headache."
Today there are about 15,000 publicly-owned wastewater treatment works in the
United States, discharging approximately 26 billion gallons per day of treated
wastewater into lakes, streams and waterways. Before treatment, this wastewater
contains over a million pounds of hazardous components. Sewage plants use heat,
chemicals and bacterial treatments to detoxify 42 percent of these components
through biodegradation. Another 25 percent escapes into the atmosphere, and 19
percent is discharged into lakes and streams. The remaining 14 percent --
approximately 28 million pounds per year -- winds up in sewage sludge.
Once created, this sludge must be disposed of in some fashion.
The available methods include: incineration (which releases pollution into the
air), dumping into landfills (which is expensive, and often lets contaminants
leach into groundwater), and ocean dumping (where it has created vast underwater
dead seas). A fourth approach -- gasification, using sludge to generate methanol
or energy -- is favored by EPA's Hugh Kaufman as the "most environmentally
sound approach, but also the most expensive."
A fifth approach -- using sludge as plant fertilizer -- was considered hazardous
to health and the environment until the 1970s, but it has the advantage of being
inexpensive. As budget concerns mounted in the late 1970s, the EPA began to
pressure sewage plants to adopt the cheapest method available -- spreading
sludge on farm fields.
RACHEL'S ENVIRONMENT & HEALTH WEEKLY #561 .
. ---August 28, 1997--- .
. HEADLINES: .
. NEW U.S. WASTE
STRATEGY, PT. 2: SEWAGE SLUDGE .
http://www.monitor.net/rachel/
www.downthedrain.org
Remediation |