PEER REVIEW OF THE PART 503 SLUDGE POLICY
John Walker has been a key player in the sludge wars. First with USDA when he reported mixing lime with
sludge or earth temporarily prevented Salmonella from being detected in laboratory tests. Then with EPA as a
lead scientist in promoting sludge as a safe fertilizer. Walker also was a leader on the part 503 Peer Review
Committee which gutted any human safety provisions that had been included in the 1989 proposed regulation.
To understand why there was no real risk assessment and why the Peer Review Committee supported EPA's
policy to undermine the Environmental Laws, we need to look at a little history leading up to the Peer Review
Committee decision and what it was.
According to EPA, the 1989 proposed Part 503 regulation to control the use and disposal of sludge was a
direct result of a court action by the Natural Resources Defense Council (NRDC) against EPA for allowing
pretreatment removal credits without a comprehensive sludge regulation. According to EPA, a comprehensive
sludge use and disposal regulation under the Clean Water Act (CWA) was promised in the preamble to the 40
CFR 257 solid waste regulation in 1979 (44 FR 53439).
The proposed Part 503 was the first part of the proposed comprehensive regulations under the CWA. In 1991,
EPA released the co-disposal rule Part 257/258 which regulated the co-disposal of sludge with solid waste.
Some limited use of sludge as a fertilizer was allowed under the CWA's restrictive provisions included in the
solid waste regulation Part 257, which classified sludge as a solid waste, that must be disposed of in a landfill.
In 1982, EPA set up an Intra-Agency Task Force, which involved a number of ad.hoc groups, to study the
complex problems involved in regulating sludge. However, "-none of these groups had been able to decide how
to equitablely regulate nationally a complex and variable waste in an environmentally protective and
cost-effective manner" (58 FR 9261). According to EPA, "Furthermore, at that time  Congress had not
provided a compliance
mechanism for the regulation."
The court held that without a comprehensive regulation under section 405 of the CWA, the pretreatment credits
could not be allowed. In spite of the fact that Part 403 controls industrial discharges to the treatment plant, EPA
claimed, "Some members of Congress expressed concern that, without sewage sludge regulations, industry
would continue to discharge toxic pollutants into wastewater for POTWs to treat, making it more difficult for a
city to find sewage
sludge management alternatives." (58 FR 9261)
Another problem EPA had to contend with was that section 405(d)(5) of the CWA, "also provides that nothing in
this section is intended to waive more stringent requirements in the CWA, or in other law," such as the RCRA.
When EPA release the proposed regulation in 1989 for comments, it only addressed some toxic organics and
some toxic metals. While EPA claimed it did a scientific review to determine the most hazardous pollutants it
needed to regulate, the only pollutants consider were those listed in the pretreatment regulation, Part 403,
which were eligible for pretreatment removal credits.
During the comment period, the Peer Review Committee found many faults with the proposed Part 503. It was
evident the regulation could not stand as written. The regulation was too conservative and would have
effectively curtailed much of the land application of sludge. EPA had too much money invested in beneficial use
research and development, too many people had built their careers on beneficial use of sludge research and
too much sludge had already been used for crop production as well as on home lawns and gardens which
could create a huge liability problem if the practice was discontinued.
Under EPA policy, states such as Missouri had been disposing of toxic heavy metals and deadly organic
chemicals at extremely high levels compared to what they would have been allowed to under the EPA proposal.
A comparison with the state of Missouri, for example, with the EPA proposed
limits shows the following differences:
Missouri Limits vs EPA's Proposed 1989 Limits
no limit on arsenic vs 12.5 lb. per acre.
no limit on Berylium vs no limit
18 lbs. of cadmium vs 1 6.0. lb. per acre.
2000 lbs. of chromium vs 472.0 lb. per acre.
500 lbs. of copper vs 41.0 lb. per acre
2000 lbs. of lead vs 111.0 lb. per acre.
no limit on mercury vs 13.4 lb. per acre.
no limit on molybdenum vs 4.5 lb. per acre.
500 lbs. of nickel vs 69.0 lb. per acre.
no limit on selenium vs 28.5 lb. per acre.
1000 lbs. of zinc vs 151.0 lb. per acre.
Another state adversely effected by the 1989 proposed Part 503 regulation was New York City. In a letter to
EPA Administrator Reilly, dated June 5, 1989, Commissioner Harvey Schultz of New York City's Department of
Environmental Protection, explained the economics of New York City's situation, if the Part 503 rule was
adopted as it was proposed. "--compliance with the pollutant standards would be difficult, if not impossible, to
achieve." "---no disposal option covered by the proposal would be allowed or feasible for eighty percent of the
City's sludge." In closing, Mr. Schultz urged Mr. Reilly; "Considering the economic and environmental
importance of these regulations, the large volume of potentially beneficial sludge affected, and the cost and
paucity of landfill space, I urge you to devote the necessary resources to revise 503 in accordance with the best
available technical information."
According to a New York City study, pretreatment by industry would not help New York City control the toxic
metals. "The 1970 to 1972 study of the sources of these heavy metals in New York City waste-water concluded
that even with zero discharge by industry, 94 percent of the zinc, 91 percent of the copper, 84 percent of the
cadmium and 80 percent of the chromium being discharged would continue to be discharged by sources
virtually immune to treatment (Ref. 1)." (Wat. Sci. Tech. (1987) Vol. 19, No. 9. p. 133)
Furthermore, the study found, "For land application, the Task 4 Report used NYDEC criteria (Table 5). It
concluded that because of metals concentration, 94% of New York City Sludge is presently unacceptable for
land application. After pretreatment, either through local limits or categorical standards, 83% to 84% of New
York City Sludges would still be unacceptable for land application. The reason for this is that non-domestic
sources of pollutant loading, not industrial sources, are primarily responsible for interfering with this sludge
use." (Wat. Sci. Tech. (1987) Vol. 19, No. 9. p. 142)
As is evident from the above examples, for some cities it would have been impossible to meet the standards for
beneficial use in the Proposed Part 503; and many sludge application sites could have already far exceeded the
EPA's Hugh Kaufman, explained part of the conversion process, which changed sludge from a regulated solid
waste to a fertilizer, at a New Hampshire conference on the "Dangers of Sludge", November 15, 1997, at the
Franklin Pierce Law Center in Concord, N.H.. In 1989 EPA proposed sludge regulations that were very similar to
the rest of the developed world--Canada, Germany, the European countries. As a result of that proposed
regulation, politicians from all over the country started pressure EPA--a young senator, Al Gore from
Tennessee, the head of the Environment Protection Agency in New York City--all of them implying and/or
stating directly that they could not land apply their sludge if EPA promulgated the regulations that were similar
to the rest of the developed world.
So what EPA did was, they did a survey of most of the big city sludges to determine the highest levels of
contaminates in those sludges, and then they modified the proposals so that all the big city sludges would be
allowed to land apply their sludge. And the first act of the Clinton/Gore Administration was to publish in the
Federal Register and implement those regulations that would allow New York City sludge to be land applied
every other place. Only a few of the toxic materials that were in the sludge are regulated, and the levels that
were set for land application were high enough so that all cities--Knoxville, Nashville, New York--would pass.
As required, once the proposed Part 503 regulation was promulgated, it had to go out for public comments and
be peer reviewed. One has only to look at the composition of the Peer Review Committee and who paid for it to
see how biased it was in favor of beneficial use. According to the Federal Register, the Peer Review Committee
consisted of the following people and their organizations, EPA, USDA, Land Grant Colleges, municipal
treatment plants, and industry, who volunteered their time. The Association of Metropolitan Sewerage Agencies
(AMSA) and the Water Environment Federation (WEF) contributed to travel expenses (58 FR 9267). The AMSA
and the WEF membership are composed of wastewater treatment plant management, engineering companies,
waste management industry, etc.
Representing EPA on the Peer Review Committee were:
Dr. John Walker, a physical scientist, who has built his career around promoting the use of sewage sludge as a
fertilizer, first with USDA, and then as an EPA employee. Walker's expertise on the committee included
management practices and metal bioavailability,
Dr. Robert Bastian, a biologist, according to 1998 documents, also served on the Part 503 Peer Review
Committee. Bastin's expertise on the committee was listed as; sludge processing, management practices and
regulatory impacts. Dr. James Ryan and Dr. Joseph Farrell, were also on the Part 503 Peer Review Committee.
Ryan's expertise was metal bioavailability and organic bioavailability. Ryan was 1 of 5 people on the committee
listed with organic bioavailability expertise and organics were dropped from the regulation.
Farrell's expertise was in processing and pathogens.
USDA was Represented on the Committee by:
Dr. Rufus Chaney, who also built a career on doing studies promoting the use of sludge as a fertilizer. His
expertise on the committee was bioavailability of metals. USDA's Dr. Robert Dowdy, whose expertise was also
Examples of members on the Committee from Land Grant Colleges
Dr. Terry Logan of the Ohio State University (OSU), who co-chaired the Peer Review Committee. Logan's
expertise on the committee was bioavailability of metals. He has been involved with beneficial sludge use
through research at the University of Ohio and employment with commercial sludge disposal firms.
Dr. Al Page of the University of California at Riverside (UCR), who was co-chair of the Peer Review Committee
with Dr. Logan was listed as a metal bioavailability expert, as was Dr. Andrew Chang, Page's colleague at UCR,
metals bioavailability expert.
There was a definite conflict of interest in the make up of the Peer Review Committee. This is an example of
what Dr. Stan Tackett called one sided science. According to Dr. Tackett, the beneficial use scientists are well
represented on scientific committees. He says, "It is no wonder then that the scientists selected by the EPA to
serve on sludge advisory committees are the "beneficial use" researchers, and the only research reports they
deem acceptable for the purpose of adopting new sludge spreading regulations are from the "beneficial use"
Some of the Peer Review members research has been funded by the EPA for a long time. Many were involved
in the 1972 NC-118 project, "Utilization and Disposal of Municipal, Industrial and Agricultural Processing Waste
on Land and the W-124 project, "Soil as a Waste Treatment System---a five year study involving the Land
Grant Universities, USDA and EPA. That was followed in 1977 by a combined effort of the two groups as the
W-124 project, "Optimum Utilization of Sewage Sludge on Land." This 5 year project involved 44 researcher
from 15 Land Grant Universities, 3 USDA laboratories, 1 EPA laboratory, 2 municipal wastewater treatment
agencies and TVA. This project was extended for two years. In 1984, the W-124 committee transformed itself
into the W-170 committee for another 5 year project, "Chemistry and Bioavailability of Waste Constituents in
Soils." This was a slightly smaller group composed of 25 researchers from 13 Land Grant Universities, 2 USDA
laboratories, 1 municipal wastewater treatment agency, 1 EPA laboratory and TVA. Some members of the
W-170 and predecessor Committees have been very busy since 1973, when it organized and conducted with
EPA, the "Joint Conference on Recycling of Municipal Sludges and Effluent on Land". In 1975, 76, and 77, it
published papers dealing with standardization and methodology, of using sludge and wastewaters on land. In
1979, it reviewed the part 257 solid waste sludge disposal regulation. It started to get serious in 1983 when a
workshop on "Utilization of Municipal Wastewater and Sludge on Land" was sponsored by, EPA, USDA, W-170
committee, the University of California Kearney Foundation of Soil Science, the U.S. Army Corps of Engineers,
and the National Science Foundation. Two years later in 1985, the W-170 committee organized and conducted
a workshop on "Land Application of Municipal Sewage Sludge." The Workshop assessed the validity of the
assumptions made in the risk assessment process on fate of sludge contaminates. "Findings of the workshop
are contained in a book entitled "Land Application of Municipal Sewage Sludge", edited by (three members of
the Peer Review Committee) A.L. Page, T.J. Logan, and J.A. Ryan. 
Some members of the W-124 committee were also on the 1987 EPA Science Advisory Board which reviewed
the Technical Documents supporting the revisions of Part 257 on the use and disposal of sewage sludge. Yet,
EPA's Science Advisor Board did not review the final Part 503 regulations for land use.
The only way the Committee could change the regulation was to attack the methodology behind the regulation.
Although the Technical Support Documents (TSDs) had been reviewed and approved by the Science Advisory
Board in 1987, which was composed of some of the same members as the Peer Review Committee, the
Committee critized the regulations as containing:
"Such extensive misinterpretation and errors in the TSDs that it is imperative that EPA review and revise them
completely. We also recommend that review and revision of the rule and the TSDs be conducted in consultation
with the PRC (Peer Review Committee) and other knowledgeable experts."
What was worse, in their view, was that beneficial use would be effectively prohibited under the new rule,
"-- the proposed rule is based on a series of worst case scenarios, which are so stringent and inflexible that
local communities are precluded from beneficial use options considered protective of the public health and the
environment under local conditions. Beneficial use is constrained because the proposed rule provides no
allowances for local conditions within and among communities. The PRC is concerned that, in spite of the
Agency's own findings that the aggregate risk for the land-based sludge utilization options are lower that
associated with other disposal options, the proposed regulations encourage non-utilization practices."
One of the key areas of Part 503 that was criticized by the Peer Review Committee was the risk assessment
method which allowed for worst case scenarios:
"The fundamental problem (mentioned repeatedly in this review) is that EPA attempts to define risk value by a
layering of worst case assumptions. As a result, what is finally arrived at is the unknown and unknowable. When
worst case assumptions are made, do they lead to the 95th percentile, the 99th percentile, the 99.99999th
percentile or what? At a certain point, which is a function of the size of the exposed population and other
variables, there is a percentile which is ridiculous and not even defined because there are no individuals in the
group (e.g., the 99.99 percentile of 100 people)."
The worse case scenarios are the same precautionary principals that European countries and Canada use to
protect their people from adverse health effects and the environment from further degradation from exposure to
The first step in their effort to gut the 1989 proposed regulation was for the Peer Review Committee to attack
the lack of science behind the regulation:
"It is evident from a review of the document that many of the conclusions reached by EPA are not driven by
science, but rather by policy decisions. In view of the inherent uncertainties in risk assessment and the
necessity for value judgements, the prominence of the policy decisions is understandable. However, instead of
acknowledging these policy decisions and justifying them on legal, political and social grounds, EPA has in
many cases, tried to make it appear that the basis for these decisions was scientific. This problem permeates
the proposed rule and technical support documents." "---We wish to emphasize that EPA has disguised policy
decisions with the risk assessment assumptions and database, apparently to make it appear that the results
derived scientifically. Had they wished to do the effort correctly they should have, at the very least, clearly
presented the underlying assumptions, data and models. Instead, these are scattered through numerous
documents in a manner that is very difficult to assess."
As noted, EPA's John Walker wrote the EPA had no cancer risk assessment.
"Even using this approach, the Agency determined the aggregate risk for all beneficial land effects-based
options to be insignificant. In fact, by their own admission, `The actual incidence may be substantially less than
predicted here and in fact may be zero' (58 FR P. 5779)
"In addition to providing an adequate level of public health and environmental protection from the 1 X 10,000
risk level reduces the regulatory impact of the rule allowing the Agency to regulate the use and disposal of
sewage sludge without needlessly burdening the regulated community or negatively impacting beneficial
reuse." (58 FR p. 9281)
At this point, the farmers and home gardeners lost any protection they might have had under the proposed
regulation. According to the Peer Review Committee:
"In our judgement, the definition of the "most exposed individual" used by the Agency is not consistent with the
Agency's intent to protect the public health and the environment from reasonably anticipated adverse effects
associated with potential sewage sludge exposure. The scenario of exposure assessed for the MEI (most
exposed individual) is unreasonable (overconservative) for the vast majority of individuals in the general
population, and substantially overestimates actual exposure for the sector(s) of the population with the highest
exposures from sewage sludge."
The Peer Review Committee recommended EPA go back to the drawing board and revise the regulation. A few
of the recommendations were:
* Revise the proposed rule to conform to their stated policy to encourage the beneficial use of
municipal sewage sludge.
To promote the use of sludge, EPA's final regulation could not take a precautionary approach to managing
sludge. "EPA concluded that adequate protection of public health and the environment did not require the
adoption of standards designed to protect human health or the environment under exposure conditions that are
unlikely and where effects were not significant or widespread." (58 FR p. 9252)
In effect, health damage to one farmer or home owner would not be
considered to be significant or widespread.
In EPA's push to promote sludge use as a fertilizer, the Agency made beneficial use more cost effective for
municipalities than surface or landfill disposal. Thus encouraging the POTWs to shift from other disposal
"Because of the expense of installing ground-water monitering wells, the Agency determined that most POTWs
reporting in the NSSS incorporated sewage sludge into the land for disposal (called dedicated land application
in the NSSS) would shift to land application rather than continue to use the land strictly for disposal.(58 FR p.
"Most of the management practices (for surface disposal under part 503) are very similar to those in Part 257
and are expected to result in negligible cost. However, unlined surface disposal units (which all are assumed to
be) are unlikely to be certified that they will not contaminate the ground water. Thus EPA assumes
ground-water monitoring must be performed. The total cost to plan the monitoring program, install the
monitoring wells, and sample and test ground water is expected to total 1.5 million per year." (58 FR p. 9375)
Under the final Part 503 concept, EPA made the choice between surface disposal and beneficial use as a
fertilizer more attractive:
"When the sewage sludge is not used to condition the soil or to fertilize crops or vegetation grown on the land,
the sewage sludge is not being land applied. It is being disposed of on the land. In that case, the requirements
in the subpart on surface disposal in the final Part 503 regulation must be met."
In effect, EPA assumed that municipalities would simply change the name of the sites, from surface disposal to
beneficial use. There would be no hassle and no cost involved. Furthermore there would be no records of
ground water contamination for them deal with.
* Enlist working groups consisting of sludge experts, risk experts and modeling
experts to review the data, revise the scenarios and obtain more
realistic estimates of pollutant limits.
These experts on the Peer Review Committee had already review the data in 1987. Why was the Peer Review
Committee questioning the work its people had already done? There work was the basis for the proposed Part
503. The Committee wanted EPA to:
* Use risk assessment procedures which lead to best estimates and uncertainty bounds
rather than calculating upperbound estimates. At a minimum, the MEI should be replaced with an
approach which considers an exposure unit that is reasonably calculated.
EPA took their advise and in the 1995 EPA Guide to the Part 503 Risk Assessment, Walker writes that, yes,
there was a risk assessment for organics in the proposed Part 503, but EPA did not include organics in the final
regulation. Walker also writes that no pathways included any toxic metal cancer
risk assessment. (p. 110)
* Use sensitivity analysis to identify the most critical parameters in risk/exposure
computation and make efforts to obtain reliable and realistic
estimates for these parameters.
Since it was not feasible to obtain reliable and realistic estimates for the parameters, EPA simply dropped the
risk/exposure computation for cancer from organics or metals.
* Adhere to normal scientific practices in the use of
the number of significant figures.
A farm family or family residence is not a significant population and any health damage would not be a
significant figure in a risk assessment. What they meant was, there are only a few people out there on the farm,
so we don't have to
worry about many people dying or complaining.
* Expand the proposed rule to include consideration of potential Fe (iron) and F (Fluoride) toxicity. -