401 KAR 8:200. Microbiological monitoring.
The system shall sample monthly according to the approved sample site plan. The number of samples required is based upon population served. Any samples that test positive for total coliform shall be analyzed for fecal coliform or E.coli. A total coliform-positive requires the following: (1) Three check samples ("C") shall be collected within 24 hours at a location five service connections upstream and downstream and at the original site; (2) If a check sample tests positive, then an additional three check samples shall be collected within 24 hours at a location five service connections upstream and downstream and at the original site of the positive check sample; (3) The water system shall repeat process #1 and #2 until all check samples are total-coliform negative; (4) Systems that collect less than five routine distribution samples ("D") per month shall collect at least five distribution samples in the next compliance month; and (5) If a boil water notice/advisory or consumer advisory has been issued for the system, the notice/advisory shall not be lifted until all check samples are total-coliform negative and the Division of Water (DOW) approves the lifting of the notice/advisory. For systems that take at least 40 or more distribution samples per month, a maximum contaminant level (MCL) violation occurs if more than 5 percent of the samples taken in any month are positive (this includes "D" and "C" samples). If a public water system collects fewer than 40 samples per month, then no more than one sample collected during any month can be total-coliform positive. An acute MCL violation occurs if there is: (1) a fecal coliform-positive check sample or E. coli-positive check sample, or (2) a total coliform-positive check sample following a fecal coliform-positive or E. coli positive distribution sample. Failure to take the proper number of samples for the month shall constitute a monitoring and reporting violation.
Technical fact sheet from EPA for total coliform.
