EPA_lacks-data

EPA's Claimed lack of Data for chemicals and still studying the problem after twenty-
five years is a total fabrication from imagination. Witness the letter to Ms Buchholz.

posted 10/14/2007

Janice Buchholz
394 Ridge Road
Prospect, VA 23960

Dear Ms. Buckholz,

Thank you for your letter of April 9, 2007 in which you present questions related to biosolids. Laronda Koffi, Virginia
State and Congressional Liaison for U.S. Environmental Protection Agency’s Region 3, referred your letter to this
office to provide responses to your questions. Your questions and EPA’s responses are presented in the attachment.

Congress charges the U.S. Environmental Protection Agency (EPA) with protecting the Nation’s land, air, and water
resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions
leading to a compatible balance between human activities and the ability of natural systems to support and nurture
life. The Clean Water Act, for example, requires that the Agency periodically reassess the scientific basis of the Part
503 rule. Also, EPA commissioned the National Research Council (NRC) of the National Academy of Science to review
the scientific basis of the regulations governing the land application of biosolids. The 2002 NRC report Biosolids
Applied to Land: Advancing Standards and Practices concluded that there is no scientific evidence the regulations do
not protect public health. The NRC also concluded that further scientific work is needed to reduce persistent concerns
about possible adverse health effects from exposure to biosolids.

Reflecting EPA’s continued commitment to the development of sound regulations, we developed a final action plan in
December 2003 aimed at strengthening the biosolids program. EPA’s research is providing data and technical
support for solving environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks
in the future.

Thank you for your letter; we share many or your interests and concerns regarding land application of sewage
sludge. I trust that this response helps clarify EPA’s position. If you would like to discuss this matter further, please
contact me at 202-566-1117 or Rick Stevens at 202-566-1135.

Sincerely,

Edward V. Ohanian, Director
Health and Ecological Criteria Division (4304T)
Office of Science and Technology
1200 Pennsylvania Avenue, NW
Washington, DC 20460

Attachment

Question: Are you coming up with mechanisms to track sludge that gets off the application site?

EPA Response: We recently conducted a collaborative study between the U.S. Environmental Protection Agency (U.
S. EPA), the U.S. Department of Agriculture (USDA), the North Carolina Department of Agriculture and Consumer
Services (NCDA&CS), and other supporting groups, agencies, and organizations. Collaborators designed the study to
investigate air and soil sampling methods and to optimize them so they could be used in future studies to obtain data
on the release of airborne and soil-bound contaminants during the application of biosolids on land. The 2005
application and study commenced at a time of the year that is typical for biosolids application; researchers completed
the field research portion in 2006. Measured and monitored were air emissions, biosolids, and related environmental
and other conditions associated with the test application. EPA is writing the report now and will make results available
to the public via an EPA website.

We are currently planning and designing a source-tracking study that will enable us to determine the origin of a
contaminant release. The goal of the study is to develop methodology for pollutant source tracking. However,
available methods are DNA-based, which means that results may be used for microorganisms only (as opposed to
chemical contaminants). For example, if one finds E. coli in a stream, one would be able to track its source and
determine where it came from (i.e., a septic tank or a wastewater treatment facility, human or animal origin, or farm or
an office building). This method may help us recognize the type of E. coli present. You may remember that last year’s
outbreaks of diarrheal disease were linked to exposure to an E. coli strain that lives in cattle, but is foreign and
pathogenic to humans.

Question: What is EPA's status on dealing with antibiotic resistance bacteria? (I want what progress you
have made and not what you are thinking about doing.) What is your critical path approach to both of
these issues? What are your time lines? What milestones have you passed?

EPA Response: EPA is aware that genes transfer between bacteria in nature. Acquisition of certain genes
makes bacteria antibiotic resistant. We are studying the movement of specific genes between bacteria rather than
within the bacteria themselves. We are reviewing the literature, and have prepared a draft fact sheet that discusses
the transfer of genes in the environment. This document considers gene transfer within sewage treatment systems,
and the initial review indicates that publicly owned treatment works (POTWs) do not appear to cause this
spread. We plan to have an antibiotic resistance, or horizontal gene transfer, fact sheet prepared by the end of
calendar year 2007.

Question: EPA has only researched a fraction of the chemicals in sludge and risk assessed only a small
subset of these and they are outdated; so tell me, what are the identities and levels of the remainder of
constituents?

EPA Response: The Clean Water Act requires EPA to review existing sewage sludge regulations every other year to
identify additional toxic pollutants in sewage sludge that might need regulation. Since 2003, EPA conducted two such
reviews of the sewage sludge regulations:

(1) EPA assessed available data on chemical pollutants that have been detected in sewage sludge and that

have not been regulated or previously assessed previously (68 FR 75531; December 31, 2003). Only 40 out of

803 pollutants had sufficient data for evaluation and potential regulation. Of the 40 pollutants evaluated, EPA

determined that 15 pollutants, subsequently reduced to nine pollutants, presented a potential risk to human

health and / or the environment based on human health and ecological risk assessments. EPA is continuing to

evaluate the nine pollutants to determine whether to propose amendments to Part 503 in order to regulate any

of these pollutants under section 405(d) of the CWA.

(2) EPA again assessed available data on chemical pollutants and performed a preliminary review of publicly

available information on pollutants. Based on a literature search from 2000 through March 2005, EPA compiled

a list of 137 chemical pollutants for which we found some information. The Agency assessed whether data for

137 pollutants were sufficient to conduct an ecological exposure and hazard assessment. Despite the collection

of valuable information for these pollutants,

EPA concluded from this review that the data were insufficient to

allow the Agency to conduct exposure and hazard assessments. At this time, there are not sufficient data to

evaluate any additional toxic pollutants in sewage sludge for potential regulation.

In addition, the Agency announced its decision that regulation of dioxin compounds in land-applied sewage sludge
was not needed for adequate protection of public health and the environment (October 17, 2003; 268 FR 61084).

For public health assessments, and to be able to assess whether a pollutant should be registered, the Agency needs,
at a minimum, adequate studies addressing toxicity to human and ecological receptors, methods for detecting
pollutant in the sewage sludge, pollutant concentration values in sewage sludge, and fate and transport data for a
pollutant in the environment. The purpose of reviewing information on pollutants, or potential pollutants, is to assess
the availability and sufficiency of the data to allow exposure and hazard assessments. Such exposure and hazard
assessments, where sufficient data exist, allow the Agency to determine the potential for harm to public
health or the environment following use or disposal of biosolids. The Agency makes determinations regarding
sufficiency of information, determining the “acceptability” of the studies and the data for three general purposes:

To conduct sewage sludge exposure and hazard assessments for humans and the environment potentially
exposed to pollutants in sewage sludge during land application or placement in surface disposal units.
To support potential rulemaking activities related to 40 CFR Part 503.
To conduct a biennial review under Clean Water Act (CWA) section 405 (d)(2)(C).

Currently, there are significant data gaps for many chemical contaminants in biosolids. There is not sufficient
information on these pollutants to evaluate even a minimal number of pathways. Examples of missing information
include analytical methods for detecting pollutants in sewage sludge, environmental properties for determining fate
and transport, adequate human health and eco-toxicity benchmarks, and concentration data in sewage sludge that
are nationally representative. Therefore, there is not sufficient information on many pollutants to conduct exposure
and hazard assessment for deriving scientifically supportable numerical standards. We continue to conduct research
in certain areas to fill these data gaps.

An example of research ongoing includes developing analytical methods for antibiotics, drugs, steroids, and
hormones. When analytical methods are available later in 2007, we will be able to analyze sewage sludge and
determine concentration levels for these pharmaceutical and personal care products in sewage sludge. A report will
be written by around March 2008.

Another example includes the Targeted National Sewage Sludge Survey. We are analyzing samples of sewage sludge
for metals, flame-retardants, semi-volatiles, polycyclic aromatic hydrocarbons, and inorganic ions (e.g., nitrate,
fluoride, and phosphorus) from 75 wastewater treatment facilities around the country. A report will be written and
issued by around September 2007.

The Agency will continue to assess the availability of sufficient information for pollutants during subsequent biennial
reviews pursuant to the CWA section 405(d)(2)(C). The next reporting period will be for the biennial review cycle
ending December 31, 2007. We will post the results of this and subsequent reviews on our biosolids website.

Question: Are these chemicals environmentally persistent in soils and do they bio-accumulate?

EPA Response: The properties of pollutants (e.g., persistence and bioaccumulation) are pollutant-specific. All of a
given pollutant’s properties (i.e., effects, persistence, bioaccumulation, and physical and chemical properties), to the
extent that data are available, factor into public health and environmental assessments. A pollutant’s properties
inform us as to whether there is potential harm via ingestion, inhalation, or contact. It may be rare, but it is possible for
a short-lived acutely toxic pollutant to represent more of a hazard than persistent and bioaccumulative ones. It is also
possible that a pollutant that is persistent and bioaccumulates will not represent a biosolids hazard, depending on
toxicity and exposure. For example, dioxins are persistent and bio-accumulative in the environment, but the Agency
concluded in 2003 that regulations for dioxins in land-applied sewage sludge was not needed for adequate protection
of public health and the environment due to its low concentration levels in biosolids.

Question: What are their interactive effects?

EPA Response: The interactive effects of pollutants in the environment, whether it is pesticides used on food crops,
chemicals released to the ambient environment, or pollutants in or released from biosolids, are not easy to determine.
The Agency’s Office of Pesticides Program utilizes an approach to assess cumulative or aggregate exposure for
pesticides with similar chemistry (e.g., organophosphates and carbamates) or similar mode of action (acetyl
cholinesterase (AChE) inhibition). Other developing methodology includes the use of bioassays and biochemical
biomarkers, such as inhibition of serum butyryl cholinesterase (BuChE) and brain (AChE); these have been useful in
studies of interactive effects of pesticides in birds. Such methodologies are of interest to the Agency and we are
continuing to follow and apply research in this area as appropriate. Such studies may be useful in assessing risk to
mammals, including humans.

Question: What are their potential effects on endpoints in addition to cancer, e.g. endocrine, neuron
developmental, and reproductive effects?

EPA Response: EPA examines both cancer and a variety of non-cancer effects when determining the susceptibility
of humans to land-applied biosolids. EPA’s evaluation of potential human exposure to pollutants from land-applied
sewage sludge includes the most highly exposed individuals (farmers who apply sewage sludge to their fields and
farm families who consume a high percentage of their own grown products). The predicted exposure results in
estimates of annual and lifetime cancer risks to members of the farm family. With respect to non-cancer effects, EPA
uses an acceptable daily dose for pollutants (also referred to as a reference dose, or RfD), which is designed to be
protective for all non-cancer effects, including reproduction, mutagenicity, teratogenicity, or other appropriate effects
(e.g., rashes and gastrointestinal upset).

Question: While new synthetic chemicals such as pharmaceuticals and additives are continually being
developed and introduced, what resources have been committed by EPA to track changes in biosolids
composition over time?

EPA Response: EPA has a strong and responsive statutory and regulatory framework to understand, manage, and
reduce hazards – including reproductive and developmental effects -- posed by chemicals in biosolids and our nation’
s waters. We have a targeted research program to develop and use new assays to test for and improve our
understanding of hazards posed by new and emerging chemicals and microbes, and we are responding to emerging
contaminants and hazards within this framework. However, these issues are not easy ones and often require
considerably more information than is available.

Our goal and commitment is to bring good science, transparency, and strong partnerships to bear to find the answers
and solutions needed to ensure that we continue to meet EPA’s central goal of protecting water quality, human and
aquatic health, and assuring safe drinking water. We work within a national framework of protecting human health and
the environment, and aquatic research, using technology and implementing regulations on a watershed basis – all
driven by a strong emphasis on sound science, transparency, public information, and partnerships. This framework
reflects requirements established by Congress under the Clean Water Act; the Safe Drinking Water Act; the Food
Quality Protection Act; the Federal Insecticide, Fungicide, and Rodenticide Act; and the Toxic Substances Control Act.

To ensure we have the best current science on endocrine disruptors, EPA is coordinating research both domestically
and internationally. Domestically, EPA is working with other federal agencies through an interagency working group
on emerging contaminants, including jointly sponsoring research with the National Institute of Environmental Health
Sciences, the National Cancer Institute, and the National Institute for Occupational Safety and Health to support
epidemiological studies investigating reproductive and developmental effects of endocrine disruptors. Internationally,
EPA led the working group that prepared the 2002 World Health Organization report on ‘Global Assessment of the
State of the Science of Endocrine Disruptors; co-sponsors workshops with the European Union and Japan; and
serves with other countries on committees under the auspices of the Organization for Economic Cooperation and
Development to harmonize testing protocol development.

Research supported by EPA is improving our ability to test for endocrine disruptors and increasing our understanding
of possible exposure routes and effects these chemicals may have on humans and wildlife. EPA is pursing a research
strategy with three goals: to support the endocrine disruptors screening and testing program; to continue providing
the underlying science on the effects, exposure, and risk management of endocrine disruptors; and to determine the
impact of endocrine disruptors on humans, wildlife and the environment. EPA is also focusing research on improving
our understanding of the underlying science for developing methods, models, and measures to help the Agency
integrate data on endocrine disruptors into its risk assessments. This research has focused on:

identifying chemicals and classes of chemicals that are endocrine disruptors and their modes of action
developing methods to evaluate the effects of mixtures of chemicals that interfere with the endocrine system by
common and different mechanisms of toxic effects;
characterizing the shape of the dose-response curves
developing approaches to extrapolate results across animal species

Equally important for determining the impact of newer chemicals (e.g., pharmaceuticals and personal care products,
endocrine disruptors, and other emerging contaminant) is applying the methods and models EPA and others are
developing to assess real-world scenarios. This work includes identifying potential sources of emerging contaminants
in the environment with a focus on wastewater treatment plants, concentrated animal feeding operations, drinking
water plants, and biosolids products.

Question: What are the agents responsible for respiratory and other symptoms reported by citizens living
near application sites?

EPA Response: We recognize that the issue of human health related to land application of biosolids is of general
public concern. Although some literature has been related to this topic, there is much disagreement and no firm
conclusions. Meanwhile, it is impossible to assign responsibility to a specific agent on basis of symptoms alone. This
area requires further study. A few reports are worth mentioning. The City of Ottawa, Canada, published in 2002 a
study titled Health Aspects of Biosolids Land Application, which was a review of the literature and stakeholder groups.
Ottawa examined a broad range of contaminants and divided them into two groups:

Group I contaminants: These have sufficient, credible scientific evidence to demonstrate that they are not a
concern in sewage biosolids
Group II contaminants: These do not have sufficient, credible scientific evidence to demonstrate they are not a
concern in sewage biosolids

The 2002 report study focused on microbial pathogens, unregulated metals, estrogenic hormones and
pharmaceutically active compounds, as well as emerging issues (PBDEs and health effects related to odors) and
health studies. There were some associations between exposure to land-applied biosolids and viral seroconversion (i.
e., horizontal gene transmission), but such associations were inconsistent among the many comparisons made,
sometimes confounded with other exposures and often of small magnitude.

There are a few field studies concerning exposure to odors, dusts, and bioaerosols. Data reported to date suggest
little or no measurable problems following exposure to biosolids. For example, a study by researchers at the
University of Arizona documented that biosolids are not a source of Staphylococcus aureus. In contrast, an article by
Schiffman et al (2000, Journal of Agromedicine, Vol.7, No.1, p.7-81) titled Potential Health Effects of Odor from Animal
Operations, Wastewater Treatment, and Recycling of Byproducts concludes that complaints of health symptoms from
ambient odors have become more frequent in communities with confined animal facilities, wastewater treatment
plants, and biosolids recycling operations. The most frequently reported health complaints include eye, nose, and
throat irritation, headache, nausea, diarrhea, hoarseness, sore throat, cough, chest tightness, nasal congestion,
palpitations, shortness of breath, stress, drowsiness, and alterations in mood. Typically, these symptoms occur at the
time of exposure and remit after a short time period. However, for sensitive individuals such as asthmatic patients,
exposure to odors may induce health symptoms that persist for a longer time, as well as aggravate existing medical
conditions.

The 2002 National Research Council-National Academy of Sciences (NRC-NAS) report, "Biosolids Applied to Land:
Advancing Standards and Practices" reviewed the epidemiological literature concerning workers and community
residents potentially exposed to biosolids during production and application. Their review included an evaluation of 23
studies relevant to the assessment of human health effects associated with biosolids exposure and divided them into
six major focus populations:

biosolids users (e.g., farmers and home gardeners)
populations near agricultural application sites
workers involved in biosolids production and application
populations near sewage treatment plants
workers in sewage treatment plants
compost workers

The NRC-NAS noted that few epidemiological studies exist, specifically for biosolids exposure. There are substantially
more studies of workers in sewage treatment plants and populations living hear them. Although those studies do not
involve exposure to biosolids per se, they were included because they provide valuable information that could identify
potential hazards from biosolids. The data could also define hazards to sewer workers and others exposed to raw
sewage. The Academies’ breakdown of the 23 studies in first three major focus populations (listed above) indicated
the following:

Biosolids users - Only one study documents chemical exposure from a vocational gardening use of biosolids (Baker
et al., 1980, Metabolic consequences of exposure to polybrominated biphenyls (PCB) in sewage sludge. Note the
date; Baker et al conducted this study prior to current regulatory requirements for biosolids and it demonstrated the
possibility of chemical contamination on land where biosolids prepared from sewage sludge with high levels of PCBs
had been land applied.

Populations near agricultural application sites - Only one study is reported concerning a population living near a
biosolids land-application site (Dorn et al., 1985, Municipal sewage sludge application on Ohio farms: Health effects.
Environ. Res. 38(2):332-359). In this 3-year health survey of farm residents, there were no differences in symptoms
or serological conversion between farm residents (population size of 164, n, persons) living near the application site
and a comparison group (n=130).

Workers in biosolids production and/or application industry - There is one study that led to the issuance of the Hazard
ID document on Class B biosolids which reported a history of gastrointestinal illness in workers handling Class B
biosolids. However, Lodor (2001) subsequently reported that the biosolids to which the workers were exposed did not
meet Class B requirements, and that NIOSH subsequently released a guidance document (NIOSH 2002, Guidance for
Controlling Potential Risks to Workers Exposed to Class B Biosolids. DHHS (NIOSH) 2002-149) for controlling
potential risks to workers exposed to Class B biosolids that supersedes the earlier Hazard ID document.

One last study is worth mentioning. In a study titled Health Risks Associated with the Treatment and Disposal of
Biosolids – A Review of Existing Studies, by Richard D Kuchenrither, et al, workers in wastewater and biosolids
treatment facilities became exposed to potential chemical and biological hazards during the course of their work.
However, this exposure has not been shown to produce an increased rate of mortality. Further, as long as common
sense personal hygiene precautions are followed, there is no indication that exposures had resulted in any increased
morbidity or acute illnesses. If operators, who are subjected to significantly higher exposures, are not suffering any
adverse consequences, than a normally healthy person who resides adjacent to our application sites and treatment
plants and experiences significantly lower exposures, will not be affected.

Question: Why has EPA relied on primitive studies of biosolids and related aerosols to conclude that
these contain no organisms or endotoxins of concern?

EPA Response: The Agency relies on state of the science models and risk assessment when assessing exposure
and hazard to human health and the environment. Current microbial risk assessments for exposure to biosolids or
related aerosols are based on cultural (microbial growth) studies conducted using methods validated as recently as
2007. We base our guidance on results of these studies. No infectious-disease outbreaks have been correlated with
biosolids exposure. Nor are there contemporary records of mass poisoning caused by microbial endotoxins.
Experience, coupled with epidemiological surveillance results, indicates that the biosolids treatments recommended in
the Part 503 regulations reduce concentration of hazardous agents -- microbial pathogens or endotoxins -- to very
low levels. These treatments reduce contamination to levels (specified within the regulation) that pose no significant
risk.

Question: Why have they used similar techniques to conclude that pathogen reduction techniques
reduce biosolid burdens to inconsequential levels when they know these techniques overlook the bulk
of microorganisms? (Common sense suggests that aerosols are produced during land applications.)

EPA Response: We are not sure what you mean by use of the term similar techniques in the phrase “…they have
used similar techniques to conclude that pathogen reduction techniques reduce biosolids burdens to inconsequential
levels when they know these techniques overlook the bulk of microorganisms.” There are many types of
microorganisms, but only some of them are pathogenic. We specifically concentrate on decreasing the concentration
of pathogenic organisms. Other biosolids microorganisms do not cause disease and positively contribute to health
and well-being.

Under the current regulations, 40 CFR Part 503, two levels of disinfection are recognized, as follows:

Class B
Processes to Significantly Reduce Pathogens (PSRP) are those processes that result in a sufficient reduction in fecal
coliform density. These processes include aerobic digestion, air drying, anaerobic digestion, composting, and lime
stabilization. Under 503, the PSRPs are recognized as processes that can achieve the Class B pathogen reduction
requirement.

Class A
Processes to Further Reduce Pathogens (PFRP) are those that could achieve non-detectable levels of pathogenic
bacteria, viruses, and parasitic ova. These processes include composting, heat drying, heat treatment, thermophilic
aerobic digestion, beta-ray irradiation, gamma-ray irradiation, pasteurization, or any of several additional treatment or
testing options. Specific approaches are acceptable under Part 503 only if they are capable of reducing levels of
pathogenic bacteria, viruses, and parasitic ova to non-detectable levels.

Question: What are the impacts on property values experienced by individual home
owners near sites of sludge application due to odors?

EPA Response: The Agency has no data concerning the impact of land-applied biosolids on property values.

Question: What are the impacts of sludge application on soil processes and soil
microbial communities?

EPA Response: Land of application of biosolids adds nutrients to soil, fertilizing macroscopic life forms such as
plants. This process is also known to alter microbial community composition subtly. Biosolids may contain
microorganisms from soil (which enters sewage via combined systems) as well as those present in the human
digestive system. The latter organisms are accustomed to living in the warm, moist, nutrient-filled gut, and do not
thrive in soil.

Question: What is the amount and percentage of sludge generated in the US that is NOW applied to land.
What is the breakdown in regards to plant crop, animal crop, silviculture, and recreational lands?

EPA Response: A recent national survey of biosolids regulation, quality, and end use and disposal survey (NEBRA
et al. 2007) shows that approximately seven million dry tons of biosolids were land applied or disposed in the U.S. in
2004. Of that total, approximately 55% was either applied to soils for agronomic, silvicultural, and land restoration
purposes, or stored for such uses. The remaining 45% were disposed of in municipal solid waste landfills, surface
disposal units, or incineration facilities.

Of the total applied to soils, 74% was used on farmlands for agricultural purposes, 1% went on forested lands, and
3% was used for land reclamation (e.g., land was reclaimed after strip mining). Another 22% was treated and tested
to meet the USEPA’s highest quality classification, “Class A EQ”, and were publicly distributed for a variety of uses
including landscaping, horticulture, and agriculture.

Question: Why has not the EPA Office of Water heeded concerns of the EPA Inspector General and the
EPA Office of Research & Development in regards to evaluating and assessing the risks of biosolids
applications?

EPA Response: This assertion is not accurate. The Office of Inspector General (OIG) issued two reports on the land
application of biosolids, in 2000 and in 2002. In 2000, the OIG raised concerns about the scientific studies regarding
risk and the resources devoted to implementing the biosolids program. From FY 2002 to FY 2003 the biosolids
program was an OIG management challenge, namely that EPA should make sure the Government Performance and
Results Act (GPRA) goal for biosolids is appropriate and readily reportable. Due to the increased EPA biosolids
activities related to our response to the NRC report, the OIG removed the biosolids program from the GPRA
management challenge list in 2005.

Currently, EPA is addressing concerns about the adequacy of the sewage sludge rule. We are also expanding
biosolids-related research and we continue to actively address biosolids violations and enforce safe land-application
of biosolids to prevent risk to human health or the environment.

Question: If the Federal Clean Water Act defines biosolids as a pollutant, how can you apply this pollutant
on land and not be charged as polluting?

EPA Response: The CWA defines pollutants broadly, including such items as dredged spoil, sewage sludge,
munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock,
sand, cellar dirt and industrial, and municipal and agricultural waste discharged into water.

However, courts have concluded that state and federal environmental laws may provide insight into the scope of the
policies' definition of pollutants without being specifically incorporated into the definitions. For example, the courts
have held that naturally occurring substances can be pollutants only when they are moved to a place differing from
where they occur naturally or are not used as intended. In fact, EPA considers essential elements such as iron,
copper, and zinc, for example, as pollutants when found in excessive amounts in the environment. Part 503 includes
standards for the use and disposal of sewage sludge. Biosolids are generated from sludge by additional sanitizing
treatments. We do not consider biosolids that are land applied according to federal and state requirements as
pollutants. We do consider the contaminants in or released from biosolids as pollutants, and these are subject to
public health and environmental assessments.

Question: What is the difference between a mile, two miles or five miles when the wind is capable of
carrying dust, odors or particles, etc. to any distance and there is no control over it?

EPA Response: The distance a pollutant may travel airborne is dependant on factors such as the composition of the
molecule and its weight and volatility. Environmental conditions, specifically including wind speed, temperature, and
humidity exert additional external controls on airborne transport, but will not be discussed here. A microbial or
chemical pollutant’s characteristics are defined by its chemical and physical properties, and are contaminant-specific.

The University of Arizona1,2,3 and other researchers have conducted a number of studies concerning biological
aerosol emission generated during wastewater treatment, sludge composting, and handling and land application of
wastewater and biosolids. Wastewater treatment and composting plants continuously generate aerosols during plant
operation, but these aerosols tend to be contained within the plants and pose the greatest risk toward the workers.

Land application sites, whether wastewater application or biosolids application sites, are of concern as communities
are beginning to encroach upon rural areas where land application occurs. However, the majority of the available
data suggest that land application operations pose little risk towards the public with respect to exposure from
aerosols. Aerosolized microorganisms generated by land application operations appear to be inactivated relatively
quickly. These organisms tend to be in stressed physiological states because of the required treatments, and the
atmospheric environment (i.e., sun, oxygen, temperature) is a much harsher environment than that of the mammalian
gut.

1/ John Brooks, Gerba, C. and Pepper, I. 2002. Biological Aerosol Emission, Fate, and Transport from Municipal and
Animal Wastes. Journal of Residuals science and Technology, Vol. 1, No. 1.
2/ J.P. Brooks, Tanner, B.D., Josephson, K.L., Gerba, C.P., Haas, C.N. and Pepper, I.L. 2005. A National Study on the
Residential Impact of Biological Aerosols From the Land Application of Biosolids. Journal of Applied Microbiology, 99,
310-322.
3/ Tanner, B.D., Brooks, J.P., Haas, C.N., Gerba, C.P. and Pepper, I.L. 2005. Bioaerosol Emission Rate and Plume
Characteristics during Land Application of Liquid Class B Biosolids, Vol 39, No. 6; 1584-1590.

Inactivation

can occur via environmental desiccation or by exposure to ultra violet light from the sun or to

oxygen radicals normally generated in fresh air. Studies indicate overall that microbial transport (in the specific

cases of fecal coliforms, fecal streptococci, mycobacteria, Clostridium perfringens, coliphage, E. coli, and

enteroviruses) beyond the application site is unlikely. We believe that the risk of infection by, or contact with,

aerosolized biosolids contaminants is low for residents who live close to application sites.

Question: What is the reason that beef or dairy cattle have to be off of the land for any amount of time if it
is considered a safe product?

EPA Response: Microorganisms carried in the guts of cattle differ slightly from those normally found in humans.
Microbial strains (subtypes) released by healthy cattle in their feces may be pathogenic toward humans. In particular,
the strain of E. coli (O157:H7) responsible for the August 2006 outbreaks of diarrhea in humans originated in cattle.
The pathogen apparently entered the food chain via crops irrigated with contaminated water. Biosolids were not
involved in the August 2006 incidents.

As we noted previously, 40 CFR Part 503 includes two levels of disinfection, Class A and Class B. Class A products
have no detectable levels of pathogens, while Class B products do. Thus, Part 503 includes operational standards as
needed. There are no time restrictions for Class A biosolids. However, for Class B biosolids, the current use, grazing,
and harvest restrictions for agricultural use of biosolids help reduce the compliant levels of pathogens to below
detectable levels.

Question: Why is hospital waste considered domestic waste when people in hospitals are ill with
contagious diseases and illnesses and their waste is flushed down the sewage pipes same as everybody
else’s?

EPA Response: Hospital waste, or at least the portion of it obtained from sick people’s urine and feces, is sanitary
waste discharged from a public or private business or center rather than from a private residence. This hospital-
generated sanitary waste is comparable to sanitary waste generated at home by sick or healthy people.

Question: All peer reviewed published scientific literature emphasizes that risks from land application
can be greatly reduced if this contaminated waste is incorporated into the soil, rather than stockpiled or
top dressed. Why does EPA still permit stockpiling and topdressing?

EPA Response: EPA supports the reuse of wastewater and the land application of biosolids as viable options
available to communities, but firmly believes that any decisions regarding those choices are local decisions subject to
meeting state regulation in addition to federal regulations. EPA also believes that the states are capable of
assessing compliance with Part 503 regulations. Sometimes stockpiling is necessary until a facility or user has an
opportunity to utilize the product. EPA is available for technical assistance and training as necessary for assessing
compliance with the 503 regulations. In addition, as long as biosolids meet Class A or Class B requirements as the
product exits the treatment facility, biosolids may be applied as the user sees fit.

Question: All peer reviewed published scientific literature emphasizes that pH needs to be kept at 6.5 or
above to prevent metals and other contaminants from mobilizing either into the food chain or into the
ground water.
Why does EPA not require pH monitoring of sludged sites?

EPA Response: Domestic septage (i.e., septic tank fluids) and biosolids applied to agricultural land, forests, or
reclamation sites must meet all of the Part 503 regulatory requirements. Among the requirements include pathogen
and vector attraction reduction. Many treatment technologies in practice, as well as certain vector attraction reduction
options, already require pH to maintained at a certain level over a certain period of time (e.g., for Alternative 2 for
Class A biosolids, pH must be maintained greater than 12 for more than 72 hours).

Question: Why did EPA deregulate the cumulative loading of molybdenum, when there is documented
evidence that this contaminant has adversely affected ruminants, i.e., cattle?

EPA Response: The molybdenum cumulative pollutant loading rate (CPLR) promulgated at Table 2 of Part 503.13
was 18 kg per hectare of land. The CPLR was determined based on an exposure pathway that evaluates the amount
of a pollutant in sewage sludge that is protective of livestock and wild animals that consume plants grown in sludge-
amended soil. In the case of molybdenum, the CPLR is designed to protect cattle from molybdenosis. EPA evaluated
additional data and information submitted by interested parties supporting a different crop uptake slope factor (i.e.,
the amount of a pollutant that is taken up by the crop) for molybdenum.

The original crop uptake slope-factor was considered an overly protective molybdenum limit. EPA amended Part 503
to delete the molybdenum pollutant limits in Tables 2, 3, and 4 of Part 503.13 pending its reconsideration of
appropriate molybdenum limits. EPA intends to assess the need and appropriate level for a numerical standard for
molybdenum in sewage sludge using additional data developed since 2000, including results from the 2006-2007
targeted national sewage sludge survey. EPA expects to complete this assessment in 2007 or 2008.

Question: EPA recently decided not to regulate dioxins and dioxin-like compounds in sludge that is land
applied claiming that the agency’s risk assessment showed such regulation was not necessary. Yet, EPA’
s risk assessment was based on the assumption that dioxin-containing sludge would be incorporated
into the soil. EPA is fully aware that half of the nation’s sludge is not incorporated but top-dressed. Why is
EPA deliberately deceiving farmers and the public by not admitting that its dioxin risk assessment is
based on incorporation?

EPA Response: The assessment for dioxins, as with any other abiotic pollutant, assumed that farmers tilled biosolids
into cropland only but not into non-tilled pastureland. We assume the farmer consumes a significant portion of his diet
from homegrown items produced on the biosolids-amended land. This scenario does not represent the general
population but intentionally reflects the risks to highly exposed individuals within the subpopulation of farmers who
apply biosolids.

With our 14-pathway exposure model, we assume that the adult farmers and their children incidentally ingest soil. We
further assume that the adult farmer ingests soil from the cropland where he has the greatest opportunity for
exposure. The children are exposed to soil concentrations at the residence location (buffer area). The buffer soil is
assumed to receive erosion, runoff, and air deposition from both the cropland (tilled) and pasture (untilled) areas.
Thus, the soil concentration in the buffer is higher than the soil concentration in the crop area, but lower than the
concentration modeled for the pasture area. All soil thought to be ingested by either the adult farmer or the child is
assumed to be from their own farm where biosolids are applied. Thus, both tilled and untilled scenarios are
represented.

Question: The human body burden of dioxin is already high. A major source of dietary dioxin is from dairy
products (cheese, milk, butter, ice cream). Along with forage, dairy cows grazing on top dressed sludge
pasture, ingest a lot of soil (in this case, they ingest sludge—which contains dioxins). They excrete
dioxins through lactation and then these dangerous chemicals concentrate in milk consumed by humans,
especially infants and children. Why does EPA still permit sludge to be applied to dairy pastures?

EPA Response: There is no evidence to suggest that EPA should restrict or not permit biosolids application to dairy
pasture. The multi-pathway risk assessment for dioxins, which includes the ingestion of dairy products, analyzed
cancer risk from exposure to dioxins in land-applied sewage sludge. The risk assessment predicted an excess lifetime
cancer risk to members of the highly exposed farm family that is in the range of cancer risks that does not warrant
additional regulation of land-applied sewage sludge. Indeed, the number of cancer cases for this farm family
population is extremely low, less than one cancer case per year and one in 100,000 over a lifetime.

Because the general population of the U.S. has lower exposure to dioxins from land-applied sewage sludge than does
the modeled farm family, the incremental cancer risk from exposure to dioxins in land-applied sewage sludge for the
general population (i.e., those not members of a highly exposed farm family) is lower than the risk to the farm family.
Therefore, having found that the existing sewage sludge land-application regulations (e.g., grazing restrictions,
agronomic rate application limitation) are adequate to protect the highly exposed population from the cancer risks due
to dioxins in land applied sewage sludge, EPA concludes that the existing regulations are adequate to protect the
general population with lower exposures.

Question: Why is EPA not heeding the 2002 National Research Council recommendation that there is an
urgent need for independent research examining the adverse effects from sludge exposure?

EPA Response: EPA is committed to ensuring that the biosolids regulations are protective of public health and
periodically reviews any new data. In December 2003, EPA released a final action plan that explains the Agency’s
response to the recommendations in the NRC report. The action plan is an important step in reducing uncertainty
about the human health effects from exposure to biosolids. EPA’s Biosolids Action Plan included 14 projects
encompassing regulatory and non-regulatory components. Examples include complying with statutory requirements of
the CWA to review existing sewage sludge regulations biennially, conducting a Targeted National Sewage Sludge
Survey of select chemical pollutants, analyzing emerging contaminants (including flame-retardants, antibiotics, drugs,
steroids, hormones); and developing a quantitative assessment of risk from pathogens.

In addition, EPA is studying the potential for pathogen reactivation when sewage sludge receives treatment via
anaerobic digestion followed by dewatering. The Agency continues to evaluate this possibility in partnership with the
Water Environment Research Foundation and other researchers. It is through this research that the Agency will
better understand the data and explain this phenomenon. EPA is also evaluating completed research projects (both
inside and outside the Agency) and carrying on or initiating other projects. The project will help us to improve risk
assessments as well, and will contribute to either developing Part 503 regulations or improving management practices.

Question: Why does EPA still claim “that there is no documented evidence that land application has
harmed people, live stock, or the environment,” when there are hundreds of reports linking sludge-
exposure to adverse effects, including human and live stock deaths, some of which have been
documented in peer reviewed scientific journals?

EPA Response: The claim that there is no documented evidence that Part 503 has failed to protect public health is
an overarching conclusion of the NRC-NAS 2002 report “Biosolids Applied to Land: Advancing Standards and
Practices.” The NAS-NRC also concluded that further work is needed to reduce the persistent scientific uncertainty
pertaining to exposure from land-applied biosolids.

EPA agrees with this statement because existing claims do not provide a reasonable basis for changing our policy
stance. To EPA’s knowledge, no claims of adverse health effects have been proven or substantiated as having been
caused by exposure to land-applied sewage sludge. Alleged adverse health effects were also considered by the NRC-
NAS in its review of EPA’s sewage sludge program. The NRC-NAS report noted that there are anecdotal reports
attributing adverse health effects to biosolids exposures, ranging from relatively mild irritant and allergic reactions to
severe and chronic health outcomes. But, the NRC-NAS concluded that a causal association between biosolids
exposures and adverse health outcomes has not been documented.

EPA’s biosolids action plan had included activities related to investigating incidents; we recognize that this is an
important issue. EPA is collaborating with the Center for Disease Control, WERF, the Office of Research and
Development, and concerned citizens in developing a protocol for investigating alleged incidents related to biosolids
exposure.

Question: If you can answer me why a product by law must disclose and label the ingredients, how is it
that biosolids can be applied on our healthy land and not have to abide by the same laws?

EPA Response: Not all consumer products contain labels that disclose ingredients. Those products that do contain
labels contain language that is based on a variety of state or federal requirements. When sewage sludge changes
hands (e.g., from treatment facility to applicator) there is a requirement that the product meets Part 503 regulation in
terms of metals and stated pathogens or pathogen indicator organisms. This requirement ensures that the product
complies with the Part 503 regulations and is thus protective of public health and the environment.