
Keeping E. coli,
Parasites Out of Drinking WaterBy Don Comis November 29, 1999Last summer, about 1,000 county fair goers in upstate New York had symptoms
that were either suspected or confirmed as being caused by infection with
Escherichia coli 0157:H7 bacteria. The likely source was drinking well
water contaminated by animal manure in rain runoff. Earlier incidents such as this had prompted the
U.S. Department of Agriculture to begin a
food safety and water quality project in 1996. The project was recently
expanded to include several of USDAs Agricultural Research Service laboratories.
As a result, microbiologist
Daniel R. Sheltonwill track the movement of E. coli and the parasite Cryptosporidium
parvum in rainwater flowing down the sides of artificial hills
called soil lysimeters. Shelton is with the ARS
Environmental Chemistry
Laboratory in Beltsville, Md. The rain is actually water sprayed from a unique ARS-designed
flexible boom that hugs the slope, ensuring that water droplets all fall an
equal distance. The 15-foot-high soil lysimeters are about 40 feet wide by 70
feet long and lined with plastic. This year, Shelton studied soil water movement. Next, hell add C.
parvum eggs to applied manure. Instead of E. coli 0157:H7,
hell trace benign E. coli strains. He will also test how well
grass strips filter out pathogens. This study is a prelude to larger scale studies that will be done in
Beltsville and on a Pennsylvania dairy farm. An article about the research appears in the November issue of ARS'
Agricultural Research magazine, and on the web at: http://www.ars.usda.gov/is/AR/archive/nov99/track1199.htm Scientific contact: Daniel R. Shelton, ARS
Environmental Chemistry
Laboratory, Beltsville, Md., phone (301) 504-6582, fax (301) 504-7976,
[email protected]. U.S. Department of Agriculture | |