SCIENCE - SAFETY - SLUDGE
Gail M. Bynum, Ph.D
PART ONE CLAIMS
Some additional research showing lime treatment did not destroy bacteria, lime treatment
creates deadly Chromium VI. Additionally, EPA specifically states it did not do a risk assessment
for toxic metals in sludge. Congressional Policy statement that solid waste (sludge) does not
cease to be a solid waste because it is being recycled or reused or reclaimed.
Dean, R. B., Proceedings of the Joint Conference on Recycling Municipal Sludges and
Effluent on Land, July 9-13-1973, pp. 39-47. Sponsored by EPA, USDA, and National
Association of State Universities and Land Grant Colleges.
EPA had a major solid waste disposal workload in 1973, it was working on solid waste disposal
regulations to implement the 1965 Solid Waste Act, which would not be completed until 1979, it
had to control sludge disposal--which did not appear to be a major problem as long as it was
heat dried, it was in the process of creating new rules to implement the Water Pollution Control
Act of 1972 and Congress was working on the Safe Drinking Water Act of 1974.
Dean's paper did note that much work remained to be done in the area of plant uptake of
metals, but the long history of sludge use indicated the hazards were slight and "probably are
easily controlled by appropriate farm practices."
However, that wasn't the case. In the discussion section of the proceedings, John Walker of the
USDA Research Station at Beltsville, Maryland, (now with EPA) discovered that EPA actually
knew very little about the nature of limed treatment destroying disease organisms in sludge or
making the metals less available to plants. (USDA didn't either, Beltsville Research Station was
declared a Superfund site in the 80's--see below)
Walker commented that, USDA had made tests to determine the fate of disease organisms over
time with limed treated soil and limed treated sludges at pH's of 8 to 11 1/2.
At first, USDA's results were identical to those reported by Dean. However, after about a month,
the pH dropped in the limed soil and salmonella was found. Similarly, when limed sludge was
mixed with soil, the pH dropped and salmonella was found even at the highest limed rates. Dean
then acknowledged that this was found very frequently and that a stabilized limed sludge, if
stored too long, would also putrefy.
Furthermore, even as EPA was giving a scientific report on how great limed sludges were, it had
a contract with Batelle Northwest of Richland, Washington to follow the behavior of limed
sludges, yet, it didn't have any information on the regrowth of salmonella. (p. 46).
Title Hazard Assessment of Contaminated Sites at Beltsville Agricultural Research
Project Description The Beltsville Agriculture Research Center (BARC) was declared a
Superfund site under the Comprehensive Environmental Response, Compensation and Liability
Act (CERCLA) in the 1980's due to historical pollution of persistent contaminants including
metals and some organic compounds. Several environmental assessments have been
conducted since then and many of the forested wetlands located on BARC property have been
identified as areas of concern.
A taste of Batelle research not used by sludge experts.
Neurotoxic chemical contaminants found at Superfund sites have the potential to
pollute water supplies and expose humans while showering, bathing, washing dishes,
doing laundry and drinking water. Little is known, however, about the magnitude of
exposure that may occur by each of the various exposure routes (inhalation,
ingestion, dermal absorption).
Children living near Superfund sites may be exposed to ground water contaminated
with neurotoxicants, which may pose a special health risk because the brain is
thought to be particularly vulnerable during childhood. Low-level toxicant exposures
may cause subtle and difficult to detect neurological defects that lead to learning
disabilities or attention deficit disorders.
Organochlorine solvents are common contaminants of groundwater and pose a particularly
important long-term health hazard to humans. Of the many organochlorine solvents, vinyl
chloride poses a greater threat to humans because it is highly prevalent, a common breakdown
product of other solvents (e.g., trichloroethylene, pentachloroethylene), and is tentatively
associated with long-term neurological dysfunction and brain cancer. The major metabolite of
vinyl chloride is chloroacetaldehyde (CAA), which is also found as a chlorination by-product in
drinking water and a toxic metabolite of some anti-cancer drugs. CAA is known to have
neurotoxic, mutagenic, and oncogenic properties. We propose that CAA induces these effects
by a mechanism similar to vinyl chloride.
The National Institute for Occupational Safety and Health (NIOSH) first recommended
standards for Occupational Exposure to Chromium (VI) in 1975. It was so concerned about the
medical and carcinogenic dangers that "Preplacement X-ray and X-rays for the 5 years
preceding termination of employment and all medical records with pertinent supporting
documents shall be retained at least 30 years after the individual's employment is terminated."
In effect, the EPA soil scientists are basing their claims for safety on the fact that the effects of
exposure to all the cancer causing agents in sludge may not show up for 20 to 30 years. By that
time no one could prove they were responsible.
But what is more damming is that one of EPA's processes for creating Class A sludge for home
and garden use also creates hexavalent chromium. Hexavalent chromium is produced by three
methods, high- lime, low-lime, and lime-free processes. No chromite ore has been mined in the
United States since 1961. In 1975, most of the chromite ore came from the Republic of South
Africa, Southern Rhodesia, and the USSR. EPA has suggested that the sewage treatment
process changes the carcinogenic nature of hexavalent chromium-VI used in the leather
industry to the non-carcinogenic form chromium-III.
For the most part we have no argument with that theory as the literature suggests that
chromium-VI at low pH (less than 4) can oxidize water to oxygen thereby resulting in chromium-III.
However, the literature also suggest that above pH 4, chromium-III will be oxidized by oxygen
into Chromium-VI. Cropland must be maintained at a pH of 6-7 to prevent other toxic metals from
being taken up by plants. In effect, all metals and particularly, chromium compounds are very
sensitive to ph balance and the oxidization process does appear to become extremely effective
in transforming natural occurring chromium-III from the soil into Chromium-VI when the pH is
raised to 11 or 12.
Yet, adding lime to sludge during the wastewater treatment process has become a relatively
common practice. It controls odors and is one of the recommended methods of treating sludge
to reduce pathogens for uncontrolled and unlabeled use on your lawns and gardens, as well as
farm land. The sludge is mixed with lime, and the pH is raised above 12, where it must remain for
at least 72 hours. In effect, it would appear the EPA's Class A treatment process is at a minimum
reactivating the chromium-VI compounds. As we saw from the Canadian study, chromium may
be one of the most dangerous elements in the sludge products EPA is promoting for
uncontrolled distribution to the public.
The EPA released "A Guide to the Biosolids Risk Assessments for the EPA Part 503 Rule" in
September 1995 which acknowledged that the risk assessment was a sham. The only cancer
risk assessment was based on a few organics that were banned or no longer manufactured, but
were never regulated.
According to the writers, EPA's John Walker, Linda Stien, Robert Southworth and James Ryan,
as well as USDA's Rufus Chaney, "--the Part 503 metals were considered noncarcinogens (they
do not cause or induce cancer) for the exposure pathways evaluated." (pp. 110-11). The
government has known for years that these metal were carcinogens. The fact is that no federal
agency offers any rules to protect the farmer -- OSHA only protects employees in the
While John Walker first reported the "regrowth problem in 1973, scientists at the Institute for
Environmental Science, Murdoch University Murdoch 6150 Australia, were still duplicating the
study in 1997.
They say, "In a soil amendment trial biosolids were mixed with sandy soil and monitored for 37
weeks. In two storage trials biosolids were stored in piles 1m high and monitored for <60 weeks.
Included in the monitoring programme were tests to determine the concentrations of faecal
coliforms, faecal streptococci and salmonellae. In both the soil amendment trials and biosolids
storage trials, concentrations of indicator organisms and salmonellae decreased through an
extended hot, dry summer period. Although these organisms were not detected in the majority of
samples taken during the summer, repopulation of faecal coliforms and salmonellae occurred in
the trials following rainfall at the beginning of the winter. In the case of one of the storage trials
repopulation occurred following a period of 50 weeks when salmonellae and faecal coliforms
were not detected. When repopulation occurred, faecal coliform concentrations increased to
higher than those at the beginning of the trials. These results suggest that faecal coliforms and
salmonellae were at undetectable concentrations through the summer period but were able to
grow when provided with favourable conditions. From this limited trial it was concluded that soil
amended with biosolids could not be considered free from pathogens for at least one year
following amendment." (Water Science and Technology Vol 35 No 11-12 pp 269275 © IWA
Publishing 1997 )
"Trust Us, We're Experts", said EPA's Robert Bastian, Alan Rubin, and John Walker. Congress
said OK, but made its intent concerning the environment very clear, "Under RCRA solid waste
do not cease to be solid waste simply because they are being used, re-used, recycled or
reclaimed. Rather, use, re-use, recycling, resource recovery and reclamation are ways of
managing solid waste, which, if properly conducted, can avoid environmental hazards, protect
scarce land supply, and reduce the nation's reliance on foreign energy and materials
---Congress' "Overriding concern" --elimination of "the last remaining loophole" in
environmental regulation" (H.R.Rep.at 4).