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EPA wants water systems that will provide water samples to evaluate a revised analytical method

EPA wants water systems that will provide water samples to evaluate a revised analytical method

 Good afternoon state drinking water administrators –

EPA’s National Homeland Security Research Center (NHSRC) and National Risk Management Research Laboratory (NRMRL) are looking for water systems willing to provide drinking water samples to support current research to improve bacterial endospore detection.   The research includes analyzing finished water samples from several utilities across the country to test the efficacy of a novel method for detecting the presence of endospores.  EPA is hoping this newer method will permit easier and more cost-effective detection, which could be useful to water utilities and other decision-makers in the event of contamination with Bacillus spp.  All supplies will be provided (three 1-liter bottles, a cooler, ice pack, and prepaid shipping label) and the identities of participating systems will be kept confidential.

If you know of water systems that may be willing to provide samples for this EPA research, please contact (or have the utility contact) Laura Boczek of NRMRL in Cincinnati.  Her contact information is included below.

Laura Boczek

This information has also been circulated by AWWA so some of your water systems may already have heard about it.  

Thanks for your help.

As background, here is some additional information on the Improved Aerobic Spore Detection Method:

Detection of indigenously occurring aerobic endospores in water is accomplished under Standard Method 9218, “Aerobic Endospores,” by exposing the sample to a heat treatment to inactivate any vegetative cells; the heat treatment does not inactivate the endospores. The sample is then plated onto a nonselective nutrient medium and incubated aerobically at 35°C. The endospores germinate and form bacterial colonies. The vast majority of these organisms will be species of Bacillus.

Heat treatment under Standard Method 9218 involves placing sample flasks into a water bath with shaker, heating at 75°C for 15 minutes, heating an additional 10 minutes at 80°C, and immediately cooling samples to room temperature in a bath containing a slurry of wet ice prior to filtering and plating.  The Des Moines Water Works (DMWW) has developed and tested a modified heat treatment method that significantly reduces the time and effort required for processing samples by eliminating the water bath and, instead, oven-heating the filters following filtration.

Under a cooperative arrangement, DMWW will continue refining and testing improvements to the method using water from DMWW Treatment Plants.  EPA will collect finished water samples from volunteer water utilities across the country that will be comparatively screened by EPA using both Method 9218 and the DMWW method to determine the number of indigenous occurring spores and the percentage of those spores that would produce false positives (assuming the samples do not contain spores) on the PLET medium.

Darrell Osterhoudt
Regulatory Affairs Manager
Association of State Drinking Water Administrators
1401 Wilson Blvd. Suite 1225
Arlington, VA 22209
(703) 812-9508
Fax (703) 812-9506

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