The EMPACT Beaches Project

August 31, 2005

The EMPACT Beaches Study report. (PDF, 83 pp., 982 KB)

EMPACT database (MS Access, 10MB) - The entire EMPACT Beaches database, in Microsoft Access format, is being provided for other researchers' use. The data in the database should be used in conjunction with the EMPACT Beaches Study report.

Background

Before the U.S. Environmental Protection Agency (EPA) was established in 1970, the Federal Water Pollution Control Administration provided monitoring guidelines that are still used today to protect the Nation's beach water quality. The Beaches Environmental Assessment and Coastal Health Act (BEACH Act), passed in 2000, tasks EPA with developing ways to reduce the risk of illness to people who use waters designated for swimming or fishing (i.e., recreational waters).

This EMPACT beaches research was done because EPA researchers noted several differences in the way state and local beach managers and other public health officials were conducting water sampling. Scientists sought to determine which elements of a beach-water quality sampling design were most critical to measurements of indicators of fecal contamination. The objective of this study was to improve monitoring of recreational water for indicator levels (i.e., how many samples to collect, where and when the samples should be collected, and how the data should be analyzed) to make public health protection for beach goers more effective.

To find answers, they selected five different bodies of recreational water to determine the influence of environmental factors, such as sunshine, tides, wind, non-point source pollution, and sampling times and locations on measurements of fecal indicators. The five beaches included two marine, two freshwater and one estuary (i.e., where the ocean extends inland to meet the mouth of a river).

Activities and Findings

During July and August 2000, EPA scientists partnered with EMPACT (Environmental Monitoring for Public Access and Community Tracking) cities, beaches and laboratories to carry out the EMPACT beaches project. Beaches included Wollaston Beach, Boston; Imperial Beach, San Diego; Miami Beach Park, Baltimore; West Beach/Lake Michigan, Gary, IN; and Belle Isle Park, Detroit. After samples were collected, they were analyzed using EPA-recommended water quality methods for bacterial indicators of fecal contamination: Escherichia coli (fresh water; 2 beaches) and enterococci (marine and estuarine water; 3 beaches).

Findings from this research, i.e., the data and statistical analyses, were reviewed by outside experts at a scientific workshop in March 2001, as well as a 2003 external peer review review panel, and are presented in a report entitled, EMPACT beaches project: Results from a study on microbiological monitoring in recreational waters (EPA600/R-04/023), U.S. EPA, Office of Research and Development, Washington, D.C, 2005.

Overall, EPA scientists observed that environmental factors affect water quality and must be considered in both the sampling design and in the interpretation of analytical results. Research results indicate that:

The greatest single influence on beach water sampling is the distance from the shoreline at which the sample is taken, as indicator densities are substantially reduced the further one moves away from the shoreline.
The study found no significant differences in indicator densities among samples taken vertically at different depths below the surface in knee-deep or chest-deep water.
Significant decreases in indicator densities were observed from the morning to the afternoon (9:00 a.m. to 2:00 p.m.) at four of the five beaches.
Fecal indicator levels were found to vary significantly from day to day. There was a limited statistical relationship observed between levels on the sampling day and the following day at three out of the five beaches studied.

Applications

Research from the EMPACT beaches project resulted in an improved and more statistically valid method that takes both sampling design and environmental factors into account. The findings provide:

Relevant and reliable information for improved national sampling and monitoring guidance for use by the Office of Water,
Technical information that state and local beach managers and other public health officials can apply when designing site-specific beach water-quality monitoring programs, and
A sampling protocol for use in EPA's current epidemiological studies underway to develop improved criteria for recreational water quality.

References

Data Quality Objectives and Statistical Design Support for Development of a Monitoring Protocol for Recreational Waters (PDF, 31 pp. 80KB), U.S. Environmental Protection Agency, Cincinnati, OH, 1999.

Health-based monitoring of recreational waters: The feasibility of a new approach (the "Annapolis protocol") (PDF, 50 pp., 323KB), WHO/SDE/WSH/99.1. World Health Organization Sustainable Development and Healthy Environments, 1999.

Wymer, L.J., A.P. Dufour, K.P. Brenner, J.W. Martinson, W.R. Stutts, and S.A. Schaub. EMPACT beaches project: Results from a study on the microbiological monitoring of recreational waters. (PDF, 83 pp., 982 KB) EPA 600/R-04/023, Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C., 2005.

EPA, Research and Development Technical Contacts

Larry Wymer
National Exposure Research Laboratory
Cincinnati, OH
(513) 569-7252 or wymer.larry@epa.gov

Kristen Brenner, Ph.D.
National Exposure Research Laboratory
Cincinnati, OH
(513) 569-7317 or brenner.kristen@epa.gov

Microbiological and Chemical Exposure Research

EPA Microbiology | Exposure Research