Residents in a York County mobile home park are being urged to boil their water before consuming it after a water sample tested positive for E. coli, according to the state Department of Health and Environmental Control.

A sample of water taken recently during routine sampling on Midnight Circle in Rock Hill tested positive for E. coli, DHEC spokesman Jim Beasley said. DHEC representatives have been distributing boil-water notices at the homes in the mobile home park, which sits just off Turkey Creek Road.

No illnesses have been reported, and the boil-water advisory is limited to the mobile home park.

“The mobile home park’s water system is a closed system,” Beasley said, “and there is no reason to believe that the E. coli-positive sample from the mobile home park’s water system would pose any threat to the surrounding area.”

DHEC investigators collected a follow-up sample and are awaiting results. The boil-water advisory will remain in effect until investigators obtain clean samples.

The park’s owner declined to comment but said he is cooperating with DHEC.

Most E. coli illnesses result from eating undercooked, contaminated ground beef, according to DHEC. Swimming in or drinking sewage-contaminated water are other possible causes, along with unwashed vegetables, salami and unpasteurized milk and juice.

Beasley clarified that most strands of E. coli are harmless, but others can cause illness, which is why DHEC distributed the notifications.