LAC 51:XII.911. Treatment Technique Triggers and Maximum Contaminant Level [formerly Total Coliform MCL of Appendix C]

A. The following conditions are considered treatment technique triggers. 1. For systems collecting 40 or more distribution system samples per month, more than 5.0 percent of the monthly samples are total coliform positive. 2. For systems collecting less than 40 distribution system samples per month, two or more samples per month are total coliform positive. 3. Failure to collect every required repeat sample following a total coliform positive sample. 4. An E.coli maximum contaminant level (MCL) violation occurs as specified below: a. a coliform-positive original sample that is also positive for E. coli is followed by a coliform-positive repeat sample; b. a coliform-positive original sample followed by a coliform-positive repeat sample is also positive for E. coli; c. failure to take all repeat samples following an E. coli positive routine sample; or d. failure to test for E. coli on any repeat total coliform positive sample. 5. A second occurrence of conditions under Paragraph 1, 2 or 3 of this Subsection within a rolling 12-month period.