Sludge Magic at the EPA
The Journal of Commerce; January 27, 1999
by David L. Lewis, Ph.D.
According to scientists working for the Environmental Protection Agency's Office of
Research & Development, the Sludge Rule on land application of municipal wastes (40
CFR Part 503) promulgated in 1993 may be the most scientifically unsound action ever
taken by the agency. Rather than being protective, the rule actually threatens public
health and the environment.
In short, EPA's sludge rule permits land application of dried urban sewage -- called
"sludge" -- in lieu of dumping it in the ocean, which is now prohibited. About half of the
sludge from municipal waste treatment facilities across the U.S., containing human
sewage, agricultural runoff and industrial wastes, is now being used to fertilize farmland,
national forests, and other areas. This amount is rapidly increasing as states and waste
disposal companies pressure local communities to use sewage sludge and assure the
public that the EPA has determined it to be virtually risk-free.
In 1972 Congress amended the Clean Water Act directing EPA to develop regulations for
disposing of sewage sludge. A U.S. District Court in Eugene, Oregon followed suit in
1990, issuing a consent decree requiring the agency to promulgate the regulations within
Remarkably, the agency's position on this issue reveals a sort of environmental
doublespeak-- traces of pesticides, heavy metals, and industrial wastes that
environmental officials have long argued cause cancer and other major public health
problems -- are now said to be completely safe for disposal on farmlands, forests, even
home lawns and gardens.
The science behind EPA's sludge rule, according to some of the agency's own scientists
who reviewed it, was so bad it was popularly deemed "sludge magic". Because sludge
contains human pathogens and trace quantities of mercury, lead, and other toxic metals,
applying it to areas used for growing food crops and selling bags of it to home gardeners
is a source of concern. Ecologists also have reservations about the effects of nutrients,
toxic metals, and other pollutants leaching from sludge into surface and groundwater.
Indeed, government researchers in Canada collaborating with scientists at the University
of Quebec last year published a study showing that forests treated with sewage sludge
released toxic metals in amounts that exceeded water-quality criteria for protecting
Disease-causing microorganisms that can lie dormant or proliferate in soil treated with
sludge are even more disconcerting to microbiologists. Samples taken this year from land
[Alice Minter Trust farm] in north Kansas City contained 650,000 salmonella and E. coli
bacteria per 100 grams of soil -many thousands of times higher that what is considered
safe by public health officials. The source, apparently, was sludge applied in the area
The appearance of new strains of staphylococcus, tuberculosis, E. coli and other bacteria
--some of which are completely resistant to modern antibiotics -- has led to a resurgence
of life-threatening infections that were once easily treated. Spreading sludge, which
contains such superbugs flushed down hospital sewer lines, on farms and home gardens
throughout the U.S. has scientists both inside and outside of EPA understandably
With increasing numbers of children dying from E. coli strain O157 traced to an
assortment of products, including strawberries and hamburger meat, citizens are
becoming increasingly concerned over agricultural products imported from less developed
areas of the world where human waste serves as cheap fertilizer. Content that syringes
and rubber gloves no longer litter our beaches, few policymakers and reporters seem
even slightly curious about how our government solved the problem of ocean dumping of
Still, it is what EPA's sludge rule says about many of the agency's other regulations that
seems most enigmatic. When asked why pesticides, organic solvents, toxic metals and
other pollutants in sludge pose virtually no risk to public health or the environment,
agency officials point to a lack of documented cases of anyone becoming sick from
exposure to sludge. Critics argue that the same can be said of traces of pesticides and
other industrial chemicals in drinking water. EPA's position on sludge, they say, shows
that agency regulations are based on political expediency, not sound science.
Dr. Lewis has a Ph.D. degree in microbial ecology, works as a research microbiologist for
the U.S. EPA Ecosystems Research Division, and is an adjunct scientist at the University
DISCLAIMER: These comments represent Dr. Lewis' personal views, not official policies of
the U.S. EPA.
This article is part of a joint study by the Lexington Institute and the Institute for Policy
Innovation, "Out of Control: Ten Case Studies in Regulatory Abuse."