August 4, 2004 - Water Quality Criteria for Bacteria for Coastal and Great Lakes Waters

Water Quality Standards for Coastal and Great Lakes Recreation
Waters, Proposed Rule
U.S. EPA Office of Water
Engineering and Analysis Division (4303)
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 requesting comments, on the proposed rule to establish water quality criteria for bacteria for coastal and Great Lakes waters that specific States and Territories have designated for swimming, bathing, surfing, or similar water contact activities and for which the State or Territory does not have in place EPA-approved bacteria criteria that are as protective of human health as EPA’s 1986 recommended bacteria criteria, in the Federal Register, Vol. 69, No. 131 on July 9, 2004, Docket No. OW-2004-0010. The following comments were developed by ASM’s Committee on Environmental Microbiology’s Subcommittee on Water, of the Public and Scientific Affairs Board.

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 applauds the EPA for developing standards that protect human health from exposure to microbial pathogens and potential pathogens while using marine and non-marine waters for recreation. The ASM recognizes that the proposed rule is intended to promote public health by establishing levels of microbial contamination that do not result in unacceptable risks for illness. The ASM further recognizes that the proposed rule would apply to States and Territories that do not have in place standards that comply with the requirements of section 303(i) of the Clean Water Act of 1986.

The ASM appreciates the importance of EPA's use of indicator species and the need to relate numbers of indicator species to risk of illness. The EPA has proposed fecal coliforms, enterococci and E. coli as suitable indicators, and established geometric mean and "single sample maximum" concentrations of each that are associated with acceptable risks of gastrointestinal illness in recreational waters used with different frequencies. In addition, the EPA has devoted considerable effort to developing suitable sampling and analytical protocols for indicator organisms in recreational waters.

Unfortunately, the ASM is concerned that the proposed rule may provide inadequate control of microorganisms that pose significant threats to human health through contamination of recreational waters.

 

The ASM offers the following recommendations in an effort to address some of the issues found in the proposed rule.

1. ISSUE: The level of acceptable risk in the proposed rule is based on criteria used in 1986, and only for gastrointestinal illness. It is not evident that the level of risk acceptable today is the same as in 1986, nor is it evident that risk assessments should be restricted to gastrointestinal illness and ignore respiratory or other illnesses associated with fecal contamination.

SOLUTION: The EPA should assess the need for revising levels of acceptable risk and for including additional illnesses associated with exposure to contaminated recreational waters.

2. ISSUE: The proposed rule continues to emphasize a select group of bacterial indicator species, even though the ecological behavior of these indicators is not fully known and may confound predictions of risk of illness. Other indicators, e.g., bacteriophages of Escherichia coli such as F+ coliphage), may prove more reliable and offer methodological advantages deriving from the use of either rapid molecular approaches and traditional but relatively rapid (e.g. 8 hours) culture-based approaches.

SOLUTION: The EPA should assess the reliability and utility of existing and new indicator species, including coliphages. In addition, the EPA should support detailed assessments of indicator species ecology, particularly with respect to persistence and growth in receiving waters and sediments.

3. ISSUE: The proposed rule properly emphasizes pathogens associated with waterborne disease, but provides for no specific monitoring or studies of pathogens. The probability of illnesses from waterborne pathogens depends on the type of contact, exposure time, pathogen concentrations in contaminated water, pathogen survival in receiving waters, pathogen transport from source to contact point, and the level of individual or population susceptibility to waterborne pathogens.

Due to the numerous sources of contamination now known to affect recreational waters, (especially combined sewer overflows) and factors such as seasonal variations in sewage discharge disinfection and pathogen accumulation in sediment and sands, specific studies of waterborne pathogens are essential. Such studies must focus on pathogen distribution, dynamics and association with disease.

New studies are particularly important for establishing risks from human and non-human sources of fecal contamination in recreational waters, and for determining the most appropriate strategies and funding allocations for wastewater management.

SOLUTION: EPA should establish a variety of adequately funded research programs, including extramural programs, to gather data on pathogen occurrence and impacts for critical recreational areas affected by combined sewage overflows and other pathogen-laden sewage discharges.

4. ISSUE: The proposed rule relies on use of geometric means and single sample maxima for assessing water quality. While these statistical approaches have merit, research since 1986 has raised questions about their utility that remain unresolved. For example, the use of arithmetic means has become a more accepted practice in other areas of applied public health microbiology, such as food safety microbiology.

SOLUTION: The EPA should conduct thorough statistical evaluations of sampling strategies (including sampling frequency) and data analysis and management to determine the most appropriate parameter(s) for use in establishing acceptable and unacceptable levels of fecal contamination.

5. ISSUE: The proposed rule presents options for excluding or exempting from regulation non-human sources of fecal contamination. The most conservative option, excluding only wildlife sources, likely requires development and routine application of new methodologies for microbial indicator species and for microbial source tracking. Furthermore, because wildlife such as waterfowl harbor known human pathogens such as Salmonella spp. and Campylobacter spp., such fecal sources can not be ignored.

SOLUTION: The EPA should support a thorough evaluation of indicators that reliably reflect human livestock fecal contamination and methodological approaches that can distinguish wildlife contamination from other sources. Evaluations should also address the risks from wildlife fecal contamination.

6. ISSUE: Because the proposed rule uses bacteriological methods that require 24 or more hours to provide results, determining fecal contamination and the actions they would trigger, such as beach postings or closures, potentially occur after the contamination subsided. Furthermore, rainfall is well known to greatly increase contamination levels in surface waters and is used as a basis for closing shell-fishing waters without waiting for bacteriological results.

SOLUTION: The EPA should embark on research and demonstration efforts to develop and evaluate rapid microbial methods, the use of rainfall data and other management tools (e.g., other geohydrographical data) as predictive tools for making management decisions about beaches.

Serious human health risks can arise from exposure to fecal contamination in recreational waters. Therefore, the ASM encourages the EPA to fully evaluate relationships between indicator species and health risks, and to incorporate a more complete understanding of indicator species ecology, microbial source tracking and sample statistics to provide adequate public health safety in coastal and Great Lakes recreational waters.

The ASM is pleased to have the opportunity to provide comments in response to the proposed rule on water quality standards in recreational waters, and hopes that these comments and recommendations are of assistance to the EPA.

Sincerely,

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

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