The testing of private water wells in and around Locust Grove, OK continues with the number testing positive for E. coli has increasing to 20.

Three additional drinking water wells were found positive for E. coli. The well testing has also found total coliform bacteria contamination in some wells.

Last year’s outbreak of the a rare strain of E. coli, known as 0111, was responsible for one death and 313 illnesses. The Country Cottage restaurant in Locust Grove, which had briefly used well water, was the common factor in the outbreak, but the precise source of the E coli 0111 has remained a mystery.

Oklahoma Attorney General Drew Edmondson, who suspects "poultry litter" from chicken farms in the area could be responsible for the E. coli contamination, turned state investigators on to the well water studies.