ADMINISTRATIVE CODE TITLE 35: ENVIRONMENTAL PROTECTION SUBTITLE F: PUBLIC WATER SUPPLIES CHAPTER I: POLLUTION CONTROL BOARD PART 611 PRIMARY DRINKING WATER STANDARDS SECTION 611.7905 VIOLATIONS
Section 611.7905 Violations
a) PFAS MCL violations, both for the individual PFOA, PFOS, HFPO-DA, PFHxS, and PFNA MCLs, as well as the Hazard Index MCL, as listed in Section 611.311(c), are based on a running annual average, as outlined under Section 611.7903.
b) Compliance with Section 611.311(c) must be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the supplier is in violation of the MCL.
c) Each failure to monitor in compliance with the requirements under Section 611.7902 is a monitoring violation.
d) Failure to notify the Agency following a MCL violation and failure to submit monitoring data in compliance with the requirements of Sections 611.7904 and 611.840 are reporting violations.
e) Results for PFAS with individual MCLs as listed in Section 611.311(c) are compared to their respective MCLs, and results for mixtures of two or more of the Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA) are compared to the Hazard Index MCL as listed in Section 611.311(c). For determining compliance with the Hazard Index MCL, if only PFBS is reported at any concentration and no other regulated PFAS are in the mixture, it is not a violation of the Hazard Index MCL. If only one of the other PFAS within the Hazard Index (HFPO-DA, PFHxS, or PFNA) is detected and the level of this PFAS exceeds its MCL as determined by Section 611.7903(f)(1)(A), only an individual MCL violation is assessed for the individual PFAS detected, and it is not a violation of the Hazard Index MCL. Exceedances of the Hazard Index caused by two or more of the Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, or PFNA) and exceedances of one or more individual MCLs can result in multiple MCL exceedances. However, in this instance, for purposes of public notification under Section 611.APPENDIX G of this part, a PWS supplier must only report the Hazard Index MCL exceedance.
BOARD NOTE: This Section derives from 40 CFR 141.905
(Source: Added at 50 Ill. Reg. 2531, effective February 17, 2026) |