- (a) For a PWS at which regulated inorganics are monitored at a frequency greater than annually, the department shall determine compliance with the MCL specified in Env-Dw 704 by a running annual average, as defined in Env-Dw 100, at each sampling point.
- (b) If the department determines that the running annual average at any sampling point is greater than the MCL as specified in Env-Dw 704, then the system shall be deemed out of compliance.
- (c) If any one sample is more than 4 times the MCL specified in Env-Dw 704, then the system shall be out of compliance.
- (d) Any sample result which is below the detection limit shall be calculated as zero for the purpose of determining the running annual average.
- (e) If a system is monitoring annually or less frequently, the system shall be deemed out of compliance with the MCLs if the level of a regulated inorganic at any sampling point is greater than the MCL. If confirmation samples are required by Env-Dw 711.05, the determination of compliance shall be based on the average of the initial and confirmation samples.
(f) If a PWS has a distribution system with portions that are hydraulically separate from other parts of the distribution system, then:
- (1) Only that part of the system in which the MCL specified in Env-Dw 704 is exceeded shall be out of compliance; and
- (2) The O/O may request approval from the department pursuant to Env-Dw 801.15 to limit the public notice to the users of only that portion of the system which is out of compliance.
Source. #9700, eff 5-1-10; amd by #10771, eff 2-1-15; ss by #12668, eff 1-1-19