1. (a) The MCL for microbiological contaminants is based on the presence or absence of total coliform bacteria in a sample.

   1. (1) For a system which collects at least 40 bacteriological samples per month, if no more than 5.0% of the samples collected during a month are total coliform-positive, the system is in compliance with the MCL.
   2. (2) For a system which collects fewer than 40 samples/month, if no more than one sample collected during a month is total coliform-positive, the system is in compliance with the MCL for total coliforms.
2. (b) Any fecal coliform-positive repeat sample or Escherichia coli-positive repeat sample, or any total coliform-positive repeat sample following a fecal coliform-positive or Escherichia coli-positive routine sample, constitutes a violation of the MCL. For purposes of the public notification requirements in §290.103(6) of this title (relating to Standards of Chemical Quality), this is a violation that is an acute risk to health.
3. (c) Compliance with the MCL for total coliform bacteria in subsections (a) and (b) of this section will be determined for each month in which the system is in operation.

Source Note:The provisions of this §290.105 adopted to be effective April 15, 1994, 19 TexReg 2282.