Sludge Watch ==> Has EPA done its Homework on Sludge?

[Maureen Reilly]

Sludgewatch Admin:

Here are the recommendations from the National Academy of Sciences Report on 
sludge spreading.   We need to see a point by point accounting
of what EPA has accomplished so far.  All we have seen is a closely held 
report that indicates that some sludges have an astonishing pathogen 
indicator
reactivation.  This research lends urgency to the need to address pathogen 
issues in land applied sludges. Here is the summary of recommendations.

Where is the EPA on these issues?  Where is the accountability?


To read the full summary see:
http://www.nap.edu/books/0309084865/html/
Biosolids Applied to Land: Advancing Standards and Practices , Board on 
Environmental Studies and Toxicology

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Overarching Recommendations


    There is uncertainty about the potential for adverse human health 
effects from exposure to biosolids. To assure the public and to protect 
public health, there is a need to update the scientific basis of the Part 
503 rule. The committee identified several data gaps and issues in 
management practices that should be addressed including:

A lack of exposure and health information on exposed populations. The 
committee recommends implementing human health studies, including short-term 
investigations of unusual episodes of release, exposure, or disease, and 
large-scale preplanned studies of exposures and their association, if any, 
with disease.

Reliance on outdated risk-assessment methods. Since 1993 when the rule was 
established, risk-assessment methods have advanced significantly. The 
committee recommends that new risk assessments be used to update the 
scientific basis of the chemical limits and the regulatory criteria for 
pathogens.

Reliance on outdated characterization of sewage sludges. Changes in 
treatment processes and chemical uses over the last decade have changed the 
composition of sewage sludges. The committee recommends a new national 
survey of chemicals and pathogens in sewage sludges and a review of 
management practices to ensure that risk assessment principles are put into 
practice.

Inadequate programs to ensure compliance with biosolids regulation. EPA 
should expand its oversight activities to include procedures to 1) assess 
the reliability of biosolids treatment processes and effectiveness of 
management practices, 2) monitor compliance with chemical and pathogen 
standards, 3) conduct environmental hazard surveillance, and 4) study human 
exposures and health.

Lack of resources devoted to EPA's biosolids program. More funding and staff 
resources are needed to implement the recommendations in this report. The 
committee also recommends that EPA delegate authority to more states to 
administer the federal biosolids regulation.

Health Effects Recommendations

    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. The Committee recommends 
that the EPA promote and support studies of exposed populations in order to 
document whether any health effects can be linked to biosolids exposure 
through the following types of studies:

Studies in response to unusual exposures and unusual occurrences of disease.

Preplanned assessment studies to characterize exposures of workers and the 
general public who come into contact with biosolids.

Complete epidemiological studies, for example, evaluating health effects in 
a group of biosolids appliers.

Chemical Standards Recommendations

    In developing the 1993 Part 503 rule, the EPA relied heavily on its 
1988-1989 National Sewage Sludge Survey to identify chemicals to regulate, 
selecting 9 inorganic chemicals (arsenic, cadmium, copper, lead, mercury, 
molybdenum, nickel, selenium, and zinc). Risk assessments were conducted on 
each chemical to establish acceptable concentration limits.

    Since 1993, new chemicals of concern have been identified, such as 
organic compounds used as flame retardants (i.e., brominated diphenyl 
ethers), pharmaceuticals and odorants. Chemicals eliminated in earlier 
selection processes because of data gaps might now be reevaluated in light 
of new data.

    To set the 1993 limits for the regulated chemicals, the EPA considered 
14 major exposure pathways, nine of which involve exposure to humans. EPA 
elected to estimate human exposure based on a theoretical, highly exposed 
individual (HEI), and gave no consideration to aggregate exposure, but 
rather evaluated each exposure pathway independently.

    The Committee made the following recommendations regarding chemical 
standards:

A new national survey of chemicals in sewage sludge should be conducted. 
Data from the survey should be used to determine whether additional 
chemicals should be considered for regulation.

Using current risk-assessment practices, EPA should reassess standards for 
regulated chemicals. Because of the diversity of exposed populations and 
environmental conditions in the United States, it is important that 
nationwide chemical regulations be based on the full range of exposure 
conditions that might occur.

Conceptual site models should be used to identify major and minor exposure 
pathways.

A hypothetical individual with reasonable maximum exposure (RME, such as a 
farm family living adjacent to an application site), rather than an HEI, 
should be evaluated for each exposure pathway. If there is likely more than 
one pathway, exposures should be added across pathways.

Representatives of stakeholders should be included in the risk-assessment 
process.

Pathogen Standards Recommendations

    EPA considered a spectrum of bacteria, viruses, and parasites in setting 
its 1993 pathogen standards. No risk assessments were conducted to establish 
these standards.
Instead, EPA established requirements to reduce pathogens by treatment or a 
combination of treatment and use restrictions. Given the variety of 
pathogens that have the potential to be present in biosolids, the committee 
supports this approach. However, the reliability of EPA's treatment 
techniques should be better documented using current pathogen detection 
technology, and more research is needed to verify that current management 
controls are adequate to maintain minimal exposure concentrations over an 
extended period of time.

The Committee recommends the following:

EPA should conduct a national survey of pathogen occurrence in raw and 
treated sewage sludges.

Quantitative microbial risk assessments (QMRAs) should be developed and used 
to establish regulatory criteria for pathogens in biosolids. QMRAs should 
include evaluation of all potential exposure pathways (e.g., transport of 
bioaerosols, runoff), and the possibility of secondary transmission of 
disease such as through person-to-person contact.
EPA should foster development of standardized methods for measuring 
pathogens in biosolids and bioaerosols.

EPA should promote research that uses improved pathogen detection technology 
to better establish the reliability of its prescribed pathogen treatment 
processes and biosolids-use controls to achieve and maintain minimal 
exposure over time.

Committee on Toxicants and Pathogens in Biosolids Applied to Land: Thomas 
Burke (Chair), Johns Hopkins University, Lawrence R. Curtis, Oregon State 
University, Charles N. Haas, Drexel University, Ellen Z. Harrison, Cornell 
University, William E. Halperin, New Jersey Medical School, John B. Kaneene 
Michigan State University, Greg Kester, Wisconsin Department of Natural 
Resources, Stephen P. McGrath, Institute for Arable Crops Research, Thomas 
E. McKone, University of California, Ian L. Pepper, University of Arizona, 
Suresh D. Pillai, Texas A&M University, Frederick G. Pohland, University of 
Pittsburgh, Robert S. Reimers, Tulane University, Rosalind A. Schoof, 
Gradient Corporation, Donald L. Sparks, University of Delaware, Robert C. 
Spear, University of California at Berkeley, Susan Martel (Study Director), 
the National Academies' Board on Environmental Studies and Toxicolgy.

Biosolids Applied to Land: Advancing Standards and Practices is available 
from the National Academy Press