August 29, 2006 – ASM Submits Comments to EPA on Revised National Pollutant Discharge Elimination System Rule

(Docket ID No. EPA-HQ-OW-2005-0037)
NPDES Permit Regulation and Effluent Limitation Guidelines for CAFOs in
Response to Waterkeeper Decision Proposed Rule

Water Docket
Environmental Protection Agency
Mail code: 4203M
1200 Pennsylvania Avenue, NW
Washington, DC 20460

The American Society for Microbiology (ASM) is submitting comments in response to the Environmental Protection Agency (EPA) notice of a proposal to revise the National Pollutant Discharge Elimination System (NPDES) permitting requirements and Effluent Limitations Guidelines and Standards (ELGs) for concentrated animal feeding operations (CAFOs) in response to the order issued by the Second Circuit Court of Appeals in Waterkeeper Alliance et al. v. EPA, 399 F.3d 486 (2nd Cir. 2005), in the Federal Register, Vol. 71, No. 126 on June 30, 2006, Docket ID No. EPA-HQ-OW-2005-0037. The following comments were developed by the ASM Public and Scientific Affairs Board Committee on Environmental Microbiology.

The ASM is the largest single life science society with more than 42,000 members, including scientists in academic, industrial, clinical, and government institutions, working in areas related to basic and applied research, the prevention and treatment of infectious diseases, laboratory and diagnostic medicine, the environment, and water and food safety.

The ASM commends the EPA for its efforts to improve management of waste from CAFO facilities, thereby reducing risks of human disease and other adverse environmental impacts. The ASM appreciates EPA’s recognition of the magnitude of the waste problems, and their significance for the animal production industry, for consumers and for the environment.

In addressing deficiencies in its proposed rule that were identified by US Court of Appeals for the Second Circuit, the EPA has taken several positive steps. The ASM remains concerned, however, that significant risks continue to exist, and that additional protective measures need to be established in order to ensure that CAFO waste does not affect human health.

Human diseases clearly result from exposure to pathogens in animal waste. Documented cases include exposure to Campylobacter spp., Cryptosporidium parvum, E. coli O157:H7, Listeria monocytogenes, and Salmonella sp., among others. These pathogens originate in diverse animal wastes under diverse circumstances. Fates in the environment, routes of exposure to humans, and short-term and long-term health outcomes can also differ significantly.

The potential risks from land application of CAFO wastes may be further exacerbated by the widespread use of relatively large amounts of antibiotics, the impact of which has not been adequately assessed, but which include the potential for increased antibiotic resistance among waste-borne pathogen populations. The long-term effects of repeated applications of pathogens in CAFO wastes have also not been adequately assessed. In particular, changes in physical, chemical and biological properties of systems treated with waste may alter the environmental fate of pathogens, and increase health risks or create new threats from existing or emerging diseases.

To ensure the safe application of CAFO waste and minimize impacts on human health, the ASM recommends that EPA implement a quantitative microbial risk assessment to establish limits for the presence in waste of specific pathogens (e.g., Campylobacter spp., Cryptosporidium parvum, E. coli O157:H7, Giardia, Listeria monocytogenes, and Salmonella spp.).

The ASM also recommends that EPA establish a framework for risk assessment that includes a science-based, ecosystem analysis of the complex relationships that exist among relevant physical, chemical and environmental variables, pathogen exposure and disease incidence. This analysis should include both short-term and long-term impacts of repeated waste application, and should consider likely changes in risk that may accompany predicted changes in regional climate regimes. Changes in seasonal and annual patterns for temperature and precipitation in particular may increase or decrease the risk of adverse health outcomes from CAFO waste.

The ASM is pleased to have the opportunity to provide comments in response to the EPA’s proposal to revise the NPDES permitting requirements and ELGs for CAFOs and hopes that these comments and recommendations are of assistance.


Ruth Berkelman, M.D., Chair, Public and Scientific Affairs Board
Gary King, Ph.D., Chair, Committee on Environmental Microbiology
Charles Haas, Ph.D., Member, Committee on Environmental Microbiology
Ian Pepper, Ph.D., Member, Committee on Environmental Microbiology
Joan Rose, Ph.D., Member, Committee on Environmental Microbiology
Mark Sobsey, Ph.D., Member, Committee on Environmental Microbiology