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The National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study: Water Quality
Water Quality Assessment
The NEEAR Water Study is a multi-year research project evaluating the health effects of persons using recreational waters for swimming, boating, diving, surfing, and other activities. Water quality is being assessed by EPA researchers using a new monitoring protocol and the currently approved membrane filter method for Enterococcus bacteria (EPA Method 1600, mEI Agar (PDF) (14pp, 110K, About PDF)). Newly developed rapid methods, such as the Quantitative Polymerase Chain Reaction Method developed by EPA researcher Dr. Richard Haughland, and the RAPTOR Fiberoptic Biosensor developed under contract with the U.S. Naval Research Laboratory, will also be evaluated.
Study Objectives
The objectives of the NEEAR Water Study are to (1) evaluate the water quality at two to three beaches per year for three years concurrently with a health study, (2) obtain and evaluate a new set of health and water quality data for the new rapid, state-of-the-art methods, and (3) develop new federal guidelines and limits for water quality indicators of fecal contamination (USEPA Office of Water) so that beach managers and public health officials can alert the public about the potential health hazards before exposure to unsafe water can occur.
Background Information
In order to meet the requirements of the Clean Water Action Plan, the Beach Action Plan, and the Beach Act of 2000, the NEEAR Water Study was developed to assist the USEPA Office of Water in formulating new health and risk guidelines for recreational water. The original USEPA recreational water health studies, initiated in 1972 and completed in 1982, were designed to determine the relationship between swimming-associated gastroenteritis and the quality of the bathing water. The water quality was measured using multiple microbial indicators of fecal contamination, including bacteria known to be associated with feces, the skin's surface, and nutrient pollution. Health endpoints were measured as self-reported symptoms or illness from both swimmers (defined as bathers who submersed their head beneath the water surface) and non-swimming controls. Health data were collected on weekends to maximize the swimmer population available, and the swimming-associated gastrointestinal rates for marine and fresh water were calculated by subtracting the illness rate in non-swimmers from the illness rate in swimmers for each type of water. Regression analysis was used to determine the "best" correlations between the microbial indicators and the health data (i.e., those linear relationships where gastrointestinal symptoms or illness rates increased as the water quality indicator densities increased). The data showed that enterococci were correlated with illness rates in both marine and fresh water, while Escherichia coli were correlated in fresh water only, and fecal coliforms showed no correlation with illness rates at all. The mathematical expression of the relationship of unfavorable health effects among swimmers to the quality of water was utilized by the USEPA Office of Water to develop water quality risk limits or guidelines, which were later used by the States to develop water quality standards. However, these health studies used the old water monitoring protocol, based on the geometric mean of five samples per month, and methods which required at least 24 hours for results to become available. If the water was not in compliance with the standard, the risk of exposure to enteric pathogens had potentially occurred long before the quality of the water was identified as being hazardous. The new health guidelines to be developed by the Office of Water using the data from the NEEAR Water Study will allow beach managers and public health officials to alert the public about the potential health hazards before exposure to unsafe water.
More information about the NEEAR Health Study is available at the NHEERL web site.
Related USEPA links:
- Beach Monitoring & Notification (http://www.epa.gov/waterscience/beaches/)
- The BEACH Program (http://www.epa.gov/ost/beaches/2000/introduction.html)