Michigan Administrative Code › Department - Environmental Quality › Drinking Water And Municipal Assistance Division › Supplying Water to the Public › Part 7 - SURVEILLANCE, INSPECTION, AND MONITORING › Section R. 325.10704h - Total coliform; repeat monitoring; E. coli

Current through Vol. 24-12, July 15, 2024
Rule 704h.
(1)
				  Total coliform rules repeat monitoring requirements are all of the following:
(a) If a sample taken under R 325.10704d to
				  R325.10704g is total coliform-positive, the supply shall collect a set of
				  repeat samples within 24 hours of being notified of the positive result. The
				  supply shall collect not fewer than 3 repeat samples for each total
				  coliform-positive sample found. The department may extend the 24-hour limit on
				  a case-by-case basis if the supply has a logistical problem in collecting the
				  repeat samples within 24 hours that is beyond its control. In the case of an
				  extension, the department shall specify how much time the system has to collect
				  the repeat sample. The department shall not waive the requirement for a supply
				  to collect repeat samples in this subdivision and subdivisions (b) to (c) of
				  this subrule.
(b) The supply shall
				  collect all repeat samples on the same day, except that the department may
				  allow a supply with a single service connection to collect the required set of
				  repeat samples over a 3-day period or to collect a larger volume repeat sample
				  or samples in 1 or more sample containers of any size, as long as the total
				  volume collected is at least 300 ml.
(c) The supply shall collect an additional
				  set of repeat samples in the manner specified in subdivisions (a) and (b) and
				  this subdivision of this subrule if 1 or more repeat samples in the current set
				  of repeat samples is total coliform-positive. The supply shall collect the
				  additional set of repeat samples within 24 hours of being notified of the
				  positive result, unless the department extends the limit under subdivision (a)
				  of this subrule. The supply shall continue to collect additional sets of repeat
				  samples until either total coliforms are not detected in 1 complete set of
				  repeat samples or the supply determines that a coliform treatment technique
				  trigger specified in R 325.10704i(1) has been exceeded as a result of a repeat
				  sample being total coliform-positive and notifies the department. If a trigger
				  identified in R 325.10704i is exceeded as a result of a routine sample being
				  total coliform-positive, the supply shall conduct 1 round of repeat monitoring,
				  but is not required to conduct more than 1 round of repeat monitoring for each
				  total coliform-positive routine sample.
(d) After a supply collects a routine sample
				  and before it learns the results of the analysis of that sample, if it collects
				  another routine sample or samples from within 5 adjacent service connections of
				  the initial sample, and the initial sample, after analysis, is found to contain
				  total coliforms, then the supply may count the subsequent sample or samples as
				  a repeat sample instead of as a routine sample.
(e) Results of all routine and re peat
				  samples taken under R 325.10704d to R 325.10704h not invalidated by the
				  department shall be used to determine whether a coliform treatment technique
				  trigger in R 325.10704i has been exceeded.