OWML: Current Projects

Project Title: Developing a method to rapidly estimate fecal-indicator bacteria concentrations in the Cuyahoga River, Cuyahoga Valley National Park.

Project chief:  Rebecca N. Bushon

Project support:  Amie M.G. Brady and Christina A. Likirdopulos

Cooperators:  Cuyahoga Valley National Park, National Park Service

Project duration:  2004-2008

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Introduction and problem:
The water quality of the Cuyahoga River within the Cuyahoga Valley National Park (CVNP) is a primary concern to park managers and to visitors of the park. The 23-mile reach of the Cuyahoga River within the park receives discharges of storm water, combined-sewer overflows, and incompletely disinfected wastewater from urban areas. These discharges result in a threat to the health of visitors who come into contact with river water during recreational use. Park managers are concerned about the threat posed to human health from exposure to disease-causing organisms.

Park managers want to promote the use of the river when it is of acceptable quality. Standard plating methods using membrane filtration to monitor the concentrations of fecal-indicator bacteria in the water take 24 hours to obtain results. The elapsed time between the occurrence of elevated fecal-indicator bacteria concentrations in recreational waters and their detection is too long to assess water quality and take adequate control measures in a timely manner. The need for a predictive tool that will provide reliable results of the current day’s fecal-indicator bacteria concentrations is widely recognized.

Goals and objectives:
The overall goal of the project is to identify a method that best provides an estimate of concentrations of fecal-indicator bacteria so that park managers can provide daily information to the public on the safety of the river for recreational use.

To achieve this goal, specific objectives of the proposed study are to:

1. test the IMS/ATP rapid method for E. coli and enterococci and determine how well its results correlate with results obtained using standard plating methods,
    

2. investigate the use of readily-measured variables, including streamflow, rainfall, turbidity, and the IMS/ATP rapid method results, as a predictive tool for E. coli or enterococci concentrations, and
    

3. test and compare the efficacy of the methods for estimating fecal-indicator bacteria concentrations.

Approach:
One approach to rapidly estimate fecal-indicator bacteria concentrations is to use an analytical method for E. coli or enterococci that provides results within 1 hour. In this study, we are testing an immunomagnetic separation (IMS)/adenosine triphosphate (ATP) rapid method. Magnetic beads that are coated with antibodies for either E. coli or enterococci are added to the water sample. This mixture is then subjected to IMS, in which the bacteria-antibody bead complex is separated from extraneous materials by use of a magnet. Following IMS, the bacterial cells are ruptured and ATP, which is the energy molecule found in living cells, is released and measured with a microluminometer. Results are recorded as relative light units (RLU).

Another approach to rapidly estimate fecal-indicator bacteria concentrations is to develop a predictive tool using water-quality and environmental variables as surrogates for concentrations of fecal-indicator bacteria. Possible surrogates that will be tested during this study include IMS/ATP rapid method results and streamflow, rainfall, and turbidity, which are measured quickly or are available as real-time data.

Publications:
Results from this study can be found in the following publications:

Using a rapid method to predict recreational water quality at Cuyahoga Valley National Park, Ohio. 2007. Bushon, R.N., Brady, A.M.G., and Plona, M.B.

Rapid method for Escherichia coli in the Cuyahoga River. 2007. Brady, A.M.G.

A method description article was submitted to the Journal of Microbiological Methods on February 6, 2008.