The private water wells around Locust Grove are not safe to drink, but an exhaustive study by the State of Oklahoma failed to find any of the deadly E. coli O111.

That was the strain that killed Chad Ingle of Pryor and sickened 340 other Oklahomans who dined at the popular Country Cottage, a Locust Grove restaurant known for its country-style fare.

The 2008 outbreak also sent 70 people to area hospitals where many required extensive periods of dialysis.

A joint study by the state’s Department of Environmental Quality (DEQ) and the Oklahoma Department of Agriculture, Food, and Forestry (ODAFF) of private water wells within a five-mile radius of Locust Grove were released this week.

The two agencies tested 113 wells, finding 76 percent initially showed bacteriological contamination.  Owners of 27 wells then disinfected their private water, but 81 percent of those continued to test positive after disinfection.

well-water-testing.jpgDisease-causing E. coli strains were found in some of the samples, but no E. coli O111 was found.

In addition to conducting the well tests, the two agencies also investigated potential sources of harmful bacteria near the contaminated wells.  “While the investigation found no definite source of contamination, potential causes for well contamination included poorly constructed or maintained wells, leaking septic systems, and domestic and farm animals in close proximity to wells,” the study authors said.

The state DEQ recommended that residents with private well water:

    * Use bottled or boiled water for drinking, cooking, and brushing teeth.
    * Get hooked up to municipal or rural public water systems.
    * Install full time filtration and chlorination systems with regular maintenance.

Well tests involve collecting water samples and subjecting them to laboratory analysis for total coliform and E. coli bacteria.  Total coliform are a group of bacteria that indicators of environmental pollution.  E coli is part of that group.

The two agencies are recommending that Oklahoma follow up with a study of the aquifer underlying Locust Grove.

The state opted to test the private wells in the Locust Grove area after Oklahoma Attorney General Drew Edmondson raised the possibility that poultry litter used by area chicken farmers was responsible for contaminating private water wells.  

The Country Cottage briefly used its private well water when their municipal water source was unexpectedly cut off.  No O111 was found in the Country Cottage’s well water.

Finding O111 after an outbreak has been an elusive venture for others.

Morbidity and Mortality Weekly Report, published by the Centers for Disease Control and Prevention (CDC), reported on the first community outbreak of infections attributable to Shiga toxin-producing E. coli O111 reported in the United States on April 21, 2000.

The outbreak occurred in 1999 when 11 campers in Tarrant County, TX were stricken by the O111 strain.

“A household cluster of E. coli O111 infection was reported in 1990 from Ohio, and outbreaks have occurred in Australia, Europe, and Japan.

“Despite investigations involving large numbers of persons in well-defined settings, the vehicle of transmission has been epidemiologically implicated and microbiologically confirmed in only one 1995 outbreak in South Australia, which was attributable to mettwurst, a dried fermented sausage,”  MMWR reported.

As for how the Texas campers came to be infected with O111, MMWR could only guess.

“The findings of the investigation suggest a point-source outbreak. Although primary infection from eating a contaminated salad item and then secondary spread through the barrel ice is a plausible hypothesis, the original source of contamination and its means of spread are unknown, ” MMWR concluded.

Photo:  Highly colorized electron scanning micrograph of microorganisms in water.  Courtesy CDC/Janice Haney Carr