Section 611.609 Determining Compliance

Section 611

TITLE 35: ENVIRONMENTAL PROTECTION

SUBTITLE F: PUBLIC WATER SUPPLIES

CHAPTER I: POLLUTION CONTROL BOARD

PART 611 PRIMARY DRINKING WATER STANDARDS

SECTION 611.609 DETERMINING COMPLIANCE

Section 611.609  Determining

Compliance

Compliance with the MCLs of

Section 611.300 or 611.301 (as appropriate) must be determined based on the

analytical results obtained at each sampling point.

a)         For suppliers that monitor at a frequency greater than annual,

compliance with the MCLs for antimony, arsenic, asbestos, barium, beryllium,

cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, or thallium is

determined by a running annual average at each sampling point.

1)         If the average at any sampling point is greater than the MCL,

then the supplier is out of compliance.

2)         If any one sample would cause the annual average to be

exceeded, then the supplier is out of compliance immediately.

3)         Any sample below the method detection limit must be calculated

at zero for the purpose of determining the annual average.

BOARD NOTE:

The "method detection limit" is different from the "detection

limit," in Section 611.600.  The "method detection limit" is the

level of contaminant that can be determined by a particular method with a 95

percent degree of confidence, as determined by the method outlined in appendix

B to 40 CFR 136, incorporated by reference at Section 611.102.

4)         If a system fails to collect the required number of samples,

compliance (average concentration) will be based on the total number of samples

collected.

b)         For suppliers that monitor annually or less frequently,

compliance with the MCLs for antimony, arsenic, asbestos, barium, beryllium,

cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, or thallium is

determined by the level of the contaminant at any sampling point

ber of samples,

compliance (average concentration) will be based on the total number of samples

collected.

b)         For suppliers that monitor annually or less frequently,

compliance with the MCLs for antimony, arsenic, asbestos, barium, beryllium,

cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, or thallium is

determined by the level of the contaminant at any sampling point. If

confirmation samples are required by the Agency, the determination of

compliance will be based on the average of the annual average of the initial

MCL exceedance and any Agency-required confirmation samples.  If a supplier

fails to collect the required number of samples, compliance (average

concentration) will be based on the total number of samples collected.

c)         Compliance with the MCLs for nitrate and nitrite is determined

based on one sample if the levels of these contaminants are below the MCLs.  If

the levels of nitrate or nitrite in the initial sample exceed the MCLs, Section

611.606 requires confirmation sampling, and compliance is determined based on

the average of the initial and confirmation samples.

d)         Arsenic sampling results must be reported to the nearest 0.001

mg/ℓ.

BOARD NOTE:  Derived from 40 CFR 141.23(i).