Part 611: PRIMARY DRINKING WATER STANDARDS

Section 611.560 Turbidity (Repealed) (Source: Repealed at 47 Ill. Reg. 16486, effective November 2, 2023) SUBPART N: INORGANIC MONITORING AND ANALYTICAL REQUIREMENTS

Section 611.591 Violation of a State-Only MCL This Section applies to State-only MCLs. If the result of analysis under Section 611.612 indicates that the level of any contaminant exceeds the State-only MCL, the CWS supplier must take certain actions: a) Report to the Agency withi…

Section 611.592 Frequency of State Monitoring This Section applies to State-only MCLs marked as "additional State requirements" in Section 611.300 and for which there are no specific monitoring, reporting, or public notice requirements among the NPDWRs. a) A CWS supplier using su…

Section 611.600 Applicability Certain suppliers must monitor to determine compliance with the State-only MCLs in Section 611.300 and the revised MCLs in 611.301, as appropriate, as this Subpart N requires: a) CWS suppliers. b) NTNCWS suppliers. c) Transient non-CWS suppliers to d…

Section 611.601 Monitoring Frequency Monitoring must be conducted as follows: a) Required Sampling 1) Each supplier must take a minimum of one sample at each sampling point at the times required by Section 611.610 beginning in the initial compliance period. 2) Each sampling point…

Section 611.602 Asbestos Monitoring Frequency The frequency of monitoring conducted to determine compliance with the MCL for asbestos in Section 611.301 is as follows: a) Unless the Agency has determined under subsection (c) that the PWS is not vulnerable, each CWS and NTNCWS sup…

Section 611.603 Inorganic Monitoring Frequency The frequency of monitoring conducted to determine compliance with the revised MCLs in Section 611.301 for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, and thallium is as foll…

Section 611.604 Nitrate Monitoring Each supplier must monitor to determine compliance with the MCL for nitrate in Section 611.301. a) Suppliers must monitor at the following frequencies: 1) CWSs and NTNCWSs A) GWSs: annually; B) SWSs and mixed systems: quarterly. BOARD NOTE: Deri…

Section 611.605 Nitrite Monitoring Each supplier must monitor to determine compliance with the MCL for nitrite in Section 611.301. a) This subsection (a) corresponds with 40 CFR 141.23(e)(1), which was applicable only until a date now past. This statement maintains consistency wi…

Section 611.606 Confirmation Samples a) If the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, or thallium indicate a level in excess of the MCL, the supplier must collect one additional samp…

Section 611.607 More Frequent Monitoring and Confirmation Sampling This Section corresponds with 40 CFR 141.23(g), which authorizes the states to require more frequent monitoring and confirmation sampling than is required under federal law. This statement maintains structural con…

Section 611.608 Additional Optional Monitoring Suppliers may conduct additional, more frequent monitoring than the minimum frequencies specified in this Subpart N, without prior approval from the Agency. The supplier must report the results of all its monitoring to the Agency. BO…

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…

Section 611.610 Inorganic Monitoring Times Each supplier must monitor, within each compliance period, at the time designated by the Agency by SEP. BOARD NOTE: Derived from 40 CFR 141.23(j) (2002). (Source: Amended at 27 Ill. Reg. 16447, effective October 10, 2003)

Section 611.611 Inorganic Analysis Analytical methods are from documents incorporated by reference in Section 611.102. The substantive rules mostly reference these by a short name Section 611.102(a) defines. Section 611.101 defines other abbreviations. a) A certified laboratory m…

Section 611.612 Monitoring Requirements for Old Inorganic MCLs a) Analyses for the purpose of determining compliance with the old inorganic MCLs of Section 611.300 are required as follows: 1) Analyses for all CWSs utilizing surface water sources must be repeated at yearly interva…

Section 611.630 Special Monitoring for Sodium a) CWS suppliers must collect and analyze one sample per plant at the entry point of the distribution system for the determination of sodium concentration levels; samples must be collected and analyzed annually for CWSs utilizing surf…

Section 611.631 Special Monitoring for Inorganic Chemicals (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004) SUBPART O: ORGANIC MONITORING AND ANALYTICAL REQUIREMENTS

Section 611.640 Definitions The following terms are defined for use in this Subpart O only. Additional definitions are located in Section 611.102. "Old MCL" means an MCL in Section 611.310. These include the MCLs identified as "additional state requirements". "Old MCLs" include t…

Section 611.641 State-Only MCLs a) An analysis of substances for the purpose of determining compliance with the State-only MCLs of Section 611.310 must be made as follows: 1) The Agency must issue a SEP requiring CWS suppliers utilizing surface water sources to collect samples du…

Section 611.645 Analytical Methods for Organic Chemical Contaminants The laboratory must analyze for the Section 611.311(a) VOCs under Section 611.646, the Section 611.311(c) SOCs under Section 611.648, the Section 611.310 State-only MCLs under Section 611.641, and the Section 61…

Section 611.646 Phase I, Phase II, and Phase V Volatile Organic Contaminants Monitoring of the Phase I, Phase II, and Phase V VOCs for the purpose of determining compliance with the MCL must be conducted as follows: a) Definitions. As used in this Section the following have the g…

Section 611.647 Sampling for Phase I Volatile Organic Contaminants (Repealed) (Source: Repealed at 19 Ill. Reg. 8613, effective June 20, 1995)

Section 611.648 Phase II, Phase IIB, and Phase V Synthetic Organic Contaminants Analysis of the Phase II, Phase IIB, and Phase V SOCs for the purposes of determining compliance with the MCL must be conducted as follows: BOARD NOTE: This Section does not apply to regulated PFAS se…

Section 611.650 Monitoring for 36 Contaminants (Repealed) (Source: Repealed at 16 Ill. Reg. 19010, effective December 1, 1992)

Section 611.657 Analytical Methods for 36 Contaminants (Repealed) (Source: Repealed at 16 Ill. Reg. 19010, effective December 1, 1992)

Section 611.658 Special Monitoring for Organic Chemicals (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004) SUBPART P: THM MONITORING AND ANALYTICAL REQUIREMENTS

Section 611.680 Sampling, Analytical, and other Requirements (Repealed) (Source: Repealed at 36 Ill. Reg. 7110, effective April 25, 2012)

Section 611.683 Reduced Monitoring Frequency (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004)

Section 611.684 Averaging (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004)

Section 611.685 Analytical Methods (Repealed) (Source: Repealed at 31 Ill. Reg. 11757, effective July 27, 2007)

Section 611.686 Modification to System (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004)

Section 611.687 Sampling for Maximum THM Potential (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004)

Section 611.688 Applicability Dates (Repealed) (Source: Repealed at 28 Ill. Reg. 5269, effective March 10, 2004) SUBPART Q: RADIOLOGICAL MONITORING AND ANALYTICAL REQUIREMENTS

Section 611.720 Analytical Methods a) A certified laboratory must use specific methods or alternative methods the Agency approved under Section 611.480 to determine whether the supplier complies with Section 611.330. 1) Gross Alpha and Beta A) Evaporation Methods. SM 302 (71); SM…

Section 611.731 Gross Alpha Monitoring for Gross Alpha Particle Activity, Radium-226, Radium-228, and Uranium a) A CWS supplier must monitor to determine whether it complies with Section 611.330(b), (c), and (e). For monitoring gross alpha particle activity, radium-226, radium-22…

Section 611.732 Beta Particle and Photon Radioactivity Monitoring and Compliance for Manmade Radioactivity. To determine compliance with the maximum contaminant levels in Section 611.330(d) for beta particle and photon radioactivity, a supplier must monitor at a specified frequen…

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 sampl…

Section 611.740 General Requirements a) This Subpart R contains National Primary Drinking Water Regulations. These Subpart R requirements for filtration and disinfection apply in addition to those applying under Subpart B. This Subpart R applies to a Subpart B system supplier ser…

Section 611.741 Standards for Filtration A PWS supplier must apply filtration treatment complying with Subpart B and this Subpart R. BOARD NOTE: This Section originally derived from 40 CFR 141.171. The Board removed provisions for unfiltered system suppliers. A supplier in Illino…

Section 611.742 Disinfection Profiling and Benchmarking a) Determination of a Supplier Required to Profile. A PWS supplier subject to this Subpart R must determine its TTHM annual average under subsection (a)(1) and its HAA5 annual average under subsection (a)(2). The annual aver…

Section 611.743 Filtration A PWS must provide treatment consisting of both disinfection, as specified in Section 611.242, and filtration treatment that complies with the requirements of subsection (a) or (b) or Section 611.250(b) or (c). a) Conventional Filtration Treatment or Di…

Section 611.744 Filtration Sampling Requirements a) Monitoring Requirements for Systems Using Filtration Treatment. In addition to monitoring required by Sections 611.531 and 611.533, a PWS subject to the requirements of this Subpart R that provides conventional filtration treatm…

Section 611.745 Reporting and Recordkeeping Requirements In addition to the reporting and recordkeeping requirements in Sections 611.261 and 611.262, a PWS supplier subject to the requirements of this Subpart R that provides conventional filtration treatment or direct filtration …

Section 611.7900 General Requirements a) The requirements of this subpart constitute the national primary drinking water regulations (NPDWRs) for PFAS. Each CWS and NTNCWS supplier must meet the requirements of this subpart including the maximum contaminant levels for the PFAS id…

Section 611.7901 Analytical Requirements a) General. 1) Suppliers must use only the analytical methods this Section specifies, each incorporated by reference in Section 611.102, to demonstrate compliance with the requirements of this Subpart AZ. 2) The following documents are inc…

Section 611.7902 (a)(5) TABLE 1: Trigger Levels for PFAS Contaminants Contaminant Trigger Level Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, PFNA) 0.5 (unitless) HFPO-DA 5 nanograms per liter (ng/l). PFHxS 5 ng/l. PFNA 5 ng/l. PFOA 2.0 ng/l. PFOS 2.0 ng/l. 6) Based on initial monitor…