Section 611.733  General Monitoring and Compliance Requirements

a)         The Agency may issue a SEP requiring more frequent monitoring than Sections 611.731 and 611.732 specify or requiring confirmation samples.  The supplier must average the results of the initial and confirmation samples to determine whether it complies.

b)         A PWS supplier must monitor at the time the Agency designates during each compliance period.

c)         Compliance.  A supplier must determine whether it complies with Section 611.330(b) through (e) based on the analytical results it obtains at each sampling point.  If one sampling point violates an MCL, the supplier violates the MCL.

1)         A supplier monitoring more than once per year must run an annual average at each sampling point to determine whether it complies with the MCL.  If the average of any sampling point is greater than the MCL, the supplier does not comply with the MCL.

2)         A supplier monitoring more than once per year immediately does not comply with an MCL if any sample result would cause the running average to exceed the MCL at any single sampling point.

3)         A supplier must include all samples it takes and analyzes under this Section and Sections 611.731 and 611.732 to determine whether it complies, even if that number is greater than the required minimum.

4)         If a supplier does not collect all required samples to determine its compliance based on a running annual average of quarterly samples, the supplier must determine whether it complies based on the running average of the samples it collected.

5)         If a sample result is less than the detection limit, the supplier must use zero to calculate the annual average, unless the supplier uses a gross alpha particle activity in lieu of radium-226 or uranium.  If the gross alpha particle activity result is less than the detection limit, the supplier must use one-half the detection limit to calculate the annual average.

d)         The Agency may issue a SEP allowing the supplier to delete results of obvious sampling or analytic errors.

e)         A CWS supplier exceeding the MCL for a radioactive contaminant in Section 611.330(b) through (e) must notify the Agency under Section 611.840 and the public under Subpart V.

BOARD NOTE:  This Section derives from 40 CFR 141.26(c).

(Source:  Amended at 47 Ill. Reg. 16486, effective November 2, 2023)