Section 611

Section 611.356 Tap Water Monitoring for Lead and Copper

a) Sampling Site Location

1) Selecting a Pool of Targeted Sampling Sites

A) Before the applicable date for beginning monitoring under subsection (d)(1), a supplier must identify a pool of targeted sampling sites complying with this Section based on the service line inventory the supplier developed under Section 611.354(a).

B) The pool of targeted sampling sites must be large enough to ensure that the supplier can collect the number of lead and copper tap samples subsection (c) requires.

C) The supplier may not include among its sampling sites any with installed POE treatment devices, and the tap the supplier uses at a sampling site may not have a POU device designed to remove inorganic contaminants. The exceptions are that a supplier monitoring under Section 611.363(a)(3)(D) and a supplier using a POE or POU device for the primary drinking water tap to meet other primary and secondary drinking water standards may sample the connected tap if all service connections on the supplier’s system have a POE or POU device to provide localized treatment to comply with those other drinking water standards.

D) A supplier monitoring under Section 611.363(a)(3)(D) may not use lead and copper sampling results to fulfill the criteria for reduced monitoring under subsection (d)(4).

2) Materials Evaluation. A supplier must use the information on lead, copper, and galvanized iron or steel it identified under 40 CFR 141.42(d) when conducting a materials evaluation and the information on lead service lines that Section 611.354(a) requires the supplier to collect to identify potential lead service line sampling sites.

BOARD NOTE: Suppliers completed identifying and reporting construction materials in their distribution systems under 40 CFR 141.42(d), so the Board omitted this requirement from the Illinois rules.

3) Sampling Site Tiers. A supplier must categorize the sampling sites within its pool according to tiers:

A) CWS Tier 1 Sampling Sites. "CWS Tier 1 sampling sites" include single-family structures the supplier serves through a lead service line. T he supplier must not use sites with lead status unknown service lines as Tier 4 sampling sites.

BOARD NOTE: This subsection (a)(3)(A) derives from segments of 40 CFR 141.86(a)(3).

B) CWS Tier 2 Sampling Sites. "CWS Tier 2 sampling sites" include buildings, including multiple-family structures, the supplier serves through a lead service line. The supplier must not use sites with lead status unknown service lines as Tier 2 sampling sites.

BOARD NOTE: This subsection (a)(3)(B) derives from segments of 40 CFR 141.86(a)(4).

C) CWS Tier 3 Sampling Sites. "CWS Tier 3 sampling sites" include single-family structures containing galvanized service lines the supplier identified as currently or formerly downstream of a lead service line or known to be downstream of a lead gooseneck, pigtail, or connector. The supplier must not use sites with lead status unknown service lines as Tier 3 sampling sites.

BOARD NOTE: This subsection (a)(3)(C) derives from segments of 40 CFR 141.86(a)(5).

D) CWS Tier 4 Sampling Sites. "CWS Tier 4 sampling sites" include single-family structures or buildings containing copper pipes with lead solder installed before June 19, 1986. The supplier must not use sites with lead status unknown service lines as Tier 4 sampling sites.

BOARD NOTE: This subsection (a)(3)(D) derives from segments of 40 CFR 141.86(a)(6).

E) CWS Tier 5 Sampling Sites. "CWS Tier 5 sampling sites" include single-family structures, including multiple-family residences, representing sites throughout the supplier’s distribution system. The supplier must not use sites with lead status unknown service lines as Tier 5 sampling sites.

BOARD NOTE: This subsection (a)(3)(E) derives from segments of 40 CFR 141.86(a)(7).

F) NTNCWS Tier 1 Sampling Sites. "NTNCWS Tier 1 sampling sites" include sites that the supplier serves through a lead service line. The supplier must not use sites with lead status unknown service lines as Tier 1 sampling sites.

BOARD NOTE: This subsection (a)(3)(F) derives from segments of 40 CFR 141.86(a)(8).

G) NTNCWS Tier 3 Sampling Sites. "NTNCWS Tier 3 sampling sites" include sites having galvanized lines the supplier identified as currently or formerly downstream of a lead service line or known to be downstream of a lead gooseneck, pigtail, or connector. The supplier must not use sites with lead status unknown service lines as Tier 3 sampling sites.

BOARD NOTE: This subsection (a)(3)(G) derives from segments of 40 CFR 141.86(a)(9).

H) NTNCWS Tier 5 Sampling Sites. "NTNCWS Tier 5 sampling sites" include sites representing sites throughout the supplier’s distribution system. Under this subsection (a)(3)(H), a site representing sites throughout the distribution system has plumbing materials commonly found at the other sites the supplier serves.

BOARD NOTE: This subsection (a)(3)(H) derives from segments of 40 CFR 141.86(a)(10).

4) Selecting Sampling Sites. A supplier must select sampling sites for its sampling pool using specific criteria:

A) CWS Suppliers. A CWS supplier must use CWS Tier 1 sampling sites, except that the supplier may include CWS Tier 2 or CWS Tier 3 sampling sites in its sampling pool under certain circumstances:

i) If multiple-family residences comprise at least 20 percent of the structures the supplier serves, the supplier may use CWS Tier 2 sampling sites in its Tier 1 sampling pool, if the supplier serves the sampling site through a lead service line.

BOARD NOTE: This subsection (a)(4)(A)(i) derives from a segment of 40 CFR 141.86(a)(3).

ii) If the CWS supplier does not have a sufficient number of CWS Tier 1 sampling sites on its distribution system, the supplier may use CWS Tier 2 sampling sites the supplier serves through a lead service line in its sampling pool; or

BOARD NOTE: This subsection (a)(4)(A)(ii) derives from a segment of 40 CFR 141.86(a)(4).

iii) If the CWS supplier does not have a sufficient number of CWS Tier 1 and CWS Tier 2 sampling sites on its distribution system, the supplier may complete its sampling pool with CWS Tier 3 sampling sites.

BOARD NOTE: This subsection (a)(4)(A)(iii) derives from a segment of 40 CFR 141.86(a)(5).

iv) If the CWS supplier does not have a sufficient number of CWS Tier 1 sampling sites, CWS Tier 2 sampling sites, and CWS Tier 3 sampling sites, the supplier must complete its sampling pool with CWS Tier 4 sampling sites.

BOARD NOTE: This subsection (a)(4)(A)(iv) derives from segments of 40 CFR 141.86(a)(6).

v) I f a CWS supplier does not have a sufficient number of CWS Tier 1, CWS Tier 2, CWS Tier 3, and CWS Tier 4 sampling sites, the CWS supplier must complete its sampling pool with CWS Tier 5 sampling sites.

BOARD NOTE: This subsection (a)(4)(A)(v) derives from a segment of 40 CFR 141.86(a)(7).

vi) A supplier may use non-residential buildings representing sites throughout its distribution system only if there are an insufficient number of single-family or multiple-family residential Tier 5 sampling sites available.

BOARD NOTE: This subsection (a)(4)(A)(vi) derives from a segment of 40 CFR 141.86(a)(7).

B) NTNCWS Suppliers

i) An NTNCWS supplier must select NTNCWS Tier 1 sampling sites for its sampling pool.

BOARD NOTE: This subsection (a)(4)(B)(i) derives from segments of 40 CFR 141.86(a)(8).

ii) If the NTNCWS supplier has an insufficient number of NTNCWS Tier 1 sampling sites, the supplier must complete its sampling pool with NTNCWS Tier 3 sampling sites.

BOARD NOTE: This subsection (a)(4)(B)(ii) derives from segments of 40 CFR 141.86(a)(9).

iii) If the NTNCWS supplier has an insufficient number of NTNCWS Tier 1 and Tier 3 sampling sites, the supplier must complete its sampling pool with Tier 5 NTNCWS sampling sites. For the purpose of this subsection (a)(4)(B)(iii), a representative site is a site where the plumbing materials are commonly found at other sites the water system serves.

BOARD NOTE: This subsection (a)(4)(B)(iii) derives from segments of 40 CFR 141.86(a)(10).

C) Suppliers with Lead Service Lines. Any supplier whose distribution system contains lead service lines must collect all samples for monitoring under this Section from sites the supplier serves through a lead service line. A supplier that cannot identify a sufficient number of sampling sites that it serves through lead service lines must still collect samples from every site the supplier serves though a lead service line and collect the remaining samples under subsections (a)(4)(A)(iii) through (a)(4)(A)(vi) or subsections (a)(4)(B)(ii) and (a)(4)(B)(iii).

BOARD NOTE: This subsection (a)(4)(C) derives from segments of 40 CFR 141.86(a)(11).

b) Sample-Collecting Methods

1) All tap samples a supplier collects for lead and copper under this Subpart G, with the exception of fifth-liter tap samples the supplier collects under subsection (b)(3) and samples the supplier collects under subsections (b)(5) and (h) must be first-draw tap samples. The supplier must analyze the first-draw tap sample for lead and copper during tap sampling periods when the supplier must monitor both contaminants. In tap sampling periods during which the supplier must monitor only lead, the supplier may analyze the first-draw tap sample for lead only.

2) First-Draw Tap Samples

A) A first-draw tap sample for lead and copper must be one liter in volume and have stood motionless at least six hours in the plumbing system of the sampling site.

B) T he supplier must use wide-mouthed bottles to collect first-draw tap samples.

C) For residential housing, the supplier must collect first-draw tap samples from the cold-water kitchen or bathroom sink tap.

D) For non-residential buildings, the supplier must collect first-draw tap samples one-liter in volume from a tap occupants typically use for consuming water.

E) The Agency-approved substitute non-first-draw tap samples the supplier collects in lieu of first-draw tap samples under subsection (b)(5) must be one liter in volume from an interior tap occupants typically use for consuming water.

F) The supplier may collect first-draw tap samples or allow residents to collect first-draw tap samples after instructing the residents in the sampling procedures this subsection (b) (2) specifies.

i) Sampling instructions the supplier provides to residents must not include instructions for removing the aerator and cleaning or flushing taps before the minimum six-hour stagnation period begins.

ii) To avoid problems of residents handling nitric acid, the supplier may acidify first-draw tap samples up to 14 days after the supplier or a resident collects the sample.

iii) After adding acid to resolubilize the metals, a sample must stand in its original container for the time the USEPA-approved method specifies before the laboratory analyzes the sample.

G) If a supplier allows residents to perform sampling under subsection (b)(2)(F), the supplier may not challenge the accuracy of sampling results based on alleged errors in sample collection.

3) Service Line Samples

A) A supplier must collect all tap samples for copper at sites it serves through a lead service line as a first-draw tap sample using the procedure in this subsection (b)(3). T he supplier must collect and analyze tap samples for copper only during tap monitoring cycles when the supplier must monitor copper.

B) First-Draw and Fifth-Liter Tap Water Samples

i) A supplier must collect tap water samples in five consecutively numbered wide-mouthed bottles after the water has stood motionless in the sampling site’s plumbing for at least six hours without flushing the tap prior to collecting the sample.

ii) The supplier must analyze first-draw tap samples for copper, when applicable, and fifth-liter tap samples for lead.

iii) The supplier must use wide-mouthed bottles to collect these samples. The supplier must collect the first-draw tap sample in the first numbered bottle, then sequentially fill each numbered bottle until the final bottle is full with the fifth-liter tap sample, constantly running the water while collecting the samples. T he fifth-liter tap sample is the final sample collected in this sequence.

iv) The supplier must collect first-draw and fifth-liter tap samples from residential housing from the cold-water kitchen or bathroom sink tap. The supplier must collect first-draw and fifth-liter tap samples from a nonresidential building at an interior cold water tap typically used for consuming water.

v) T he supplier may itself collect first-draw and fifth-liter tap samples or allow residents to collect the samples after instructing the residents on the sampling procedures in this subsection (b)(3)(B). The sampling instructions the supplier provides to customers must not direct the customer to remove the aerator or clean or flush the taps before the minimum six-hour stagnation period begins. To avoid problems from residents handling nitric acid, the supplier may acidify first-draw tap samples up to 14 days after the resident collects the sample. A fter the supplier acidifies the sample to resolubilize the metals, the sample must stand in its original container for the time a USEPA-approved method provides before analysis. I f the supplier allows residents to sample, the supplier may not challenge the accuracy of sampling results based on alleged errors collecting samples.

4) Follow-Up First-Draw Tap Samples

A) A supplier must collect each follow-up first-draw tap sample from the same sampling site where the previous sample originated. A supplier must collect each follow-up fifth-liter tap sample from the same sampling site where the previous sample originated.

B) If the supplier cannot access a sampling site to collect a follow-up tap sample for reasons beyond the control of the supplier, the supplier may collect the follow-up tap sample from another sampling site in its sampling pool, as long as the new site meets the same targeting criteria and is within reasonable proximity of the original site.

5) Substitute Non-First-Draw Tap Samples

A) A NTNCWS supplier or a CWS supplier meeting the criteria in Sections 611.355(b)(7)(A) and (b)(7)(B) not having enough taps for first-draw tap samples or fifth-liter tap samples meeting the six-hour minimum stagnation time may apply to the Agency in writing for a SEP allowing the supplier to substitute non-first-draw, first-draw, or fifth-liter tap samples that do not meet the six-hour minimum stagnation time.

B) A supplier approved to substitute non-first-draw tap samples must collect as many first-draw or fifth-liter tap samples from interior taps typically used for consuming water, as possible and must identify sampling times and locations that likely give the longest standing time for the remaining sites.

C) The Agency may grant a SEP waiving the requirement for prior Agency approval of sites not meeting the six-hour stagnation time.

c) Number of Samples

1) A supplier must collect at least one sample each from the number of sites in the first column of Table D (labelled "standard monitoring") during each six-month tap monitoring cycle subsection (d) specifies.

2) A supplier conducting reduced monitoring under subsection (d)(4) must collect at least one sample each from the number of sites in the second column of Table D (labelled "reduced monitoring") during each reduced tap monitoring cycle subsection (d)(4) specifies. The reduced monitoring sites must represent the sites standard monitoring requires. A supplier whose system has fewer than five drinking water taps capable of use for human consumption that meet the sampling site criteria of subsection (a) must collect multiple samples from individual taps to reach the required number of sampling sites Table D requires. To accomplish this, the supplier must collect at least one sample from each tap, then additional samples from those taps on different days during the tap sampling period, to collect a total number of samples meeting the required number of sampling sites. Alternatively, the Agency may issue a SEP allowing the supplier whose system has fewer than five drinking water taps to collect a number of samples that is fewer than the number of sites this subsection (c) specifies if the Agency determines that the supplier samples 100 percent of all taps capable of use for human consumption and that the reduced number of samples will produce the same results as collecting multiple samples from some taps. The Agency must base any SEP approving a reduced minimum number of samples on a request from the supplier or Agency on on-site verification. The Agency may specify sampling locations in a SEP when a system conducts reduced monitoring.

d) Timing of Monitoring

1) Standard Monitoring. Standard monitoring is a six-month tap monitoring cycle beginning on January 1 or July 1 of a year during which the supplier monitors at the standard number of sites under subsection (c).

A) A supplier having lead service lines, including a supplier Section 611.351(b)(3) deems to have optimized or re-optimized OCCT or a supplier that did not monitor complying with this Section (i.e., selecting sites under subsection (a), collecting samples under subsection (b), etc.) before January 16, 2024, must begin its first standard tap monitoring cycle on January 1, 2025. A fter completing the first standard monitoring cycle, the supplier must monitor under subsection (d)(1)(B).

B) A supplier that completed monitoring complying with this Section (i.e., selecting sites under subsection (a), collecting samples under subsection (b), etc.) before January 16, 2024 or a supplier that completed monitoring under subsection (d)(1)(A), must continue monitoring:

i) A supplier not meeting the criteria in subsection (d)(4) must conduct standard monitoring.

ii) A supplier meeting the criteria in subsection (d)(4) must continue to monitor under subsection (d)(4).

iii) A supplier monitoring at a reduced frequency under subsection (d)(4) and exceeding the lead or copper action level must resume standard monitoring on January 1 immediately after the tap monitoring cycle during which the supplier exceeded the action level. T he supplier must also monitor water quality parameters as Section 611.357(b), (c), or (d) require.

iv) A supplier monitoring at a reduced frequency and exceeding the lead trigger level but not the copper action level must monitor no less frequently than annually and must collect samples from the standard number of sites that subsection (c) establishes. The supplier must begin this monitoring in the calendar year after the tap monitoring cycle during which the supplier exceeded the lead trigger level. The supplier must also monitor water quality parameters as Section 611.357(b), (c), or (d) require.

v) A supplier failing to operate at or above the minimum value or within the range of values for the water quality parameters the Agency specifies under Section 611.352(f) for more than nine days in any water quality monitoring period Section 611.357 specifies must conduct standard tap water monitoring and resume sampling for water quality parameters under Section 611.357(d). T he supplier must begin this standard monitoring no later than the six-month tap monitoring cycle beginning January 1 of the calendar year after the supplier fails to comply with the Agency-specified water quality parameters.

vi) A supplier becoming a large supplier not applying corrosion control treatment or any large supplier not applying corrosion control treatment having a 90th percentile lead concentration exceeding the lead practical quantitation limit must conduct standard monitoring for at least two consecutive six-month tap monitoring cycles, then continue monitoring under this subsection (d)(1)(B)(vi).

2) Monitoring after Installing Initial or Re-Optimized Corrosion Control Treatment, Installing Source Water Treatment, Adding a New Source, or a Change in Treatment

A) A supplier install ing or re-optimizing corrosion control treatment after exceeding the lead or copper action level must monitor for lead and copper every six months and comply with applicable Agency-designated water quality parameter values until the Agency issues a SEP specifying new water quality parameter values for optimal corrosion control.

B) A supplier reoptimizing corrosion control treatment as a result of exceeding the lead trigger level but not exceeding the lead or copper action level must annually monitor for lead at the standard number of sites subsection (c) requires. T he supplier must triennially analyze samples for copper. A small or mid-sized supplier not exceeding the lead trigger level in three annual tap monitoring cycles may reduce lead monitoring under subsection (d)(4).

C) A supplier installing source water treatment under Section 611.353(a)(3) must monitor every six months until the supplier is at or below lead and copper action levels for two consecutive six-month tap sampling periods. A supplier not exceeding the lead or copper action level for two consecutive six-month tap monitoring cycles may reduce monitoring under subsection (d)(4).

D) I f a supplier gives prior notice to the Agency under Section 611.360(a)(3) of adding a new source or making a long-term change in treatment, the supplier must monitor every six months at the standard number of sites subsection (c) requires until the supplier is at or below the lead and copper action levels for two consecutive six-month monitoring cycles, unless the Agency issues a SEP determining that adding the new source or making the long-term change in treatment is not significant and does not warrant more frequent monitoring. A supplier not exceeding the lead action level, copper action level, or lead trigger level for two consecutive six-month tap sampling periods may reduce monitoring under subsection (d)(4).

3) Monitoring after the Agency Specifies Water Quality Parameter Values for OCCT

A) After the Agency specifies the values for water quality control parameters under Section 611.352(f), the supplier must conduct standard monitoring for two consecutive six-month tap monitoring cycles.

B) A supplier that must complete the re-optimization steps in Section 611.351(d) after exceeding the lead trigger level but not exceeding the lead or copper action level must monitor for two consecutive six-month tap monitoring cycles. T he supplier may then reduce monitoring under subsection (d)(4) after the Agency issues a SEP approving reduced monitoring.

4) Reduced Monitoring Based on 90th Percentile Concentrations. Reduced monitoring refers to an annual or triennial tap monitoring cycle. A supplier’s 90th percentile concentration determines the reduced monitoring frequency.

A) Reducing to Annual Monitoring for Suppliers Meeting the Criteria for Reduced Monitoring. A supplier meeting the criteria for reduced monitoring under subsection (d)(4) must collect these samples from sampling sites the supplier identified under subsection (a). A supplier monitoring annually or less frequently must conduct lead and copper tap sampling during June, July, August, or September, unless the Agency approves a different tap sampling period under subsection (d)(4)(A)(i)

i) The Agency may grant a SEP approving a different tap sampling period for conducting lead and copper tap sampling to a supplier collecting samples at a reduced frequency. The duration of the period must not exceed four consecutive months within one calendar year and must represent a time of normal operation when the highest lead levels are most likely to occur. For a NTNCWS supplier not operating during any of the months June through September and whose normal operating period when the highest levels of lead are most likely to occur is not known, the Agency must designate a period that represents a time of normal operation for the system. This reduced monitoring can only begin during the Agency-designated period in the calendar year immediately following the end of the second six-month tap monitoring cycle, for a supplier initiating annual monitoring, or in the three-year period following the end of the third consecutive year of annual monitoring, for a supplier initiating triennial monitoring.

ii) A supplier monitoring annually and collecting samples during the months of June through September that receives Agency approval to alter its tap sampling period under subsection (d)(4)(A)(i) must collect its next round of samples during a time period ending no later than 21 months after its previous round of sampling. A supplier monitoring once every three years and collecting samples during the months of June through September that receives Agency approval to alter its tap sampling period under subsection (d)(4)(A)(i) must collect its next round of samples during a time period ending no later than 45 months after the previous tap sampling period. The supplier must conduct subsequent monitoring annually or once every three years, as this Section requires.

iii) A small supplier collecting samples during the months of June through September, receiving a waiver under subsection (g) and receiving Agency approval to alter its tap sampling period under subsection (d)(4)(A)(i) must collect its next round of samples before the end of the nine-year tap monitoring cycle (as Section 611.101 defines the term).

B) A supplier meeting the lead trigger level and copper action level during two consecutive six-month tap monitoring cycles may reduce its monitoring frequency to annual monitoring and must sample at the standard number of sampling sites for lead and reduced number of sites for copper that subsection (c) specifies. A supplier operating OCCT must also maintain the range of OWQPs the Agency set under Section 611.352(f) during the same period and receive a SEP from the Agency approving annual monitoring based on the Agency’s review of the supplier’s monitoring, treatment, and other relevant information the supplier reports under Section 611.360. T he supplier must begin this sampling no later than the calendar year immediately following the last calendar year during which the supplier sampled.

C) A supplier exceeding the lead trigger level but neither the lead nor copper action level during two consecutive six-month tap monitoring cycles must monitor no less frequently than annually at the standard number of sampling sites for lead and copper subsection (c) specifies. A supplier operating OCCT must also maintain the range of OWQPs the Agency set under Section 611.352(f) during the same period and receive a SEP from the Agency approving annual monitoring based on the Agency’s review of monitoring, treatment, and other relevant information the supplier reports under Section 611.360. The supplier must begin this sampling no later than the calendar year immediately following the last calendar year during which the supplier sampled.

D) A supplier exceeding the lead trigger level but neither the lead nor copper action level during three consecutive years of monitoring may increase the tap monitoring cycle (reduce its monitoring frequency) for copper to once every three years; however, the supplier may not increase the tap monitoring cycle (reduce its monitoring frequency) for lead. A supplier operating OCCT must also maintain the range of OWQPs the Agency set under Section 611.352(f) during the same period and receive a SEP from the Agency approving triennial monitoring based on the Agency’s review of monitoring, treatment, and other relevant information the supplier reports under Section 611.360. The supplier must begin this sampling no later than the third calendar year immediately following the last calendar year during which the supplier sampled.

E) A small or mid-sized supplier not exceeding the lead trigger level or copper action level during three consecutive years of monitoring (completing standard monitoring during both six-month tap monitoring cycles of a calendar year constitutes one year of monitoring) may sample at the reduced number of sites for lead and copper that subsection (c) provides and reduce its monitoring frequency to triennially monitoring. A supplier operating OCCT must also maintain the range of OWQPs the Agency set under Section 611.352(f) during the same three-year period and receive a SEP from the Agency approving triennial monitoring based on the Agency’s review of monitoring, treatment, and other relevant information the supplier reports under Section 611.360. The supplier must begin this sampling no later than three calendar years after the last calendar year during which the supplier sampled.

F) A supplier demonstrating for two consecutive six-month tap monitoring cycles that its 90^th percentile lead concentration, calculated under Section 611.350(c)(4), is less than or equal to 0.005 mg/L and that its 90th percentile copper concentration, calculated under Section 611.350(c)(4), is less than or equal to 0.65 mg/L may sample at the reduced number of sites for lead and copper under subsection (c) and reduce its monitoring to triennially. A supplier applying corrosion control treatment must maintain the range of water quality parameter values reflecting OCCT the Agency specifies under Section 611.352(f) to qualify for reduced monitoring under this subsection (d)(4)(F).

e) Additional Monitoring. The supplier and the Agency must consider the results of any monitoring the supplier conducts in addition to the minimum requirements in this Section (such as customer-requested sampling) in making any determinations (i.e., calculating the 90^th percentile lead concentration or copper action level) under this Subpart G. A supplier serving through lead service lines that cannot collect the minimum number of samples from Tier 1 or Tier 2 sites must calculate the 90th percentile concentration using data from all sites it serves through lead service lines (Tier 1 and Tier 2 sites) together with the highest lead and copper results from lower-tier sites to complete the minimum number of sampling sites subsection (c) requires. The supplier must submit data from additional Tier 3, Tier 4 or Tier 5 sites to the Agency but may not use these results in calculating the 90th percentile concentration. The supplier must include customer-requested samples from sites the supplier knows it serves through lead service lines in calculating its 90th percentile concentration if the samples comply with this Section.

f) Invalidation of Lead and Copper Tap Samples Used in Calculating the 90th Percentile Concentration. A sample the Agency invalidates under this subsection (f) does not count toward determining lead or copper 90^th percentile concentrations under Section 611.350(c)(4) or toward meeting the minimum monitoring requirements of subsection (c).

1) The Agency must invalidate a lead or copper tap water sample if it determines that any of certain conditions exists:

A) The laboratory establishes that improper sample analysis caused erroneous results;

B) The supplier took the sample from a site that did not meet the site selection criteria in this Section;

C) The sample container sustained damage in transit; or

D) There is substantial reason to believe that someone tampered with the sample.

2) The supplier must report the results from all samples to the Agency and submit all supporting documentation for samples the supplier believes the Agency should invalidate.

3) To invalidate a sample under subsection (f)(1), the Agency must document its decision and rationale for the decision in writing. The Agency may not invalidate a sample solely because a follow-up sample result is higher or lower than that of the original sample.

4) The supplier must collect replacement samples for any samples the Agency invalidates under this Section if the supplier has too few samples to meet the minimum requirements of subsection (c) after the Agency invalidates samples. The supplier must take any replacement samples as soon as possible but no later than the latter of 20 days after the Agency invalidates the original sample or before the end of the applicable tap sampling period. The supplier must not use replacement samples it takes after the end of the applicable tap sampling period to meet the monitoring requirements of a subsequent tap sampling period. The supplier must take replacement samples at the same locations where it took the invalidated samples or, if that is not possible, at other locations the supplier did not use for sampling during the tap sampling period.

g) Monitoring Waivers for Suppliers Serving 3,300 or Fewer Persons. Any supplier serving 3,300 or fewer persons complying with the criteria in this subsection (g) may apply to the Agency for a SEP reducing its lead and copper monitoring frequency under this Section to once every nine years (i.e., a "full waiver") if the supplier complies with all of the materials criteria subsection (g)(1) specifies and all of the monitoring criteria subsection (g)(2) specifies. Any supplier serving 3,300 or fewer persons complying with the criteria subsections (g)(1) and (g)(2) only for lead or copper may apply to the Agency for a SEP reducing its tap water monitoring frequency to once every nine years for that contaminant only (i.e., a "partial waiver").

1) Materials Criteria. The supplier must demonstrate that its distribution system, service lines, and all drinking water supply plumbing, including plumbing conveying drinking water within all residences and buildings connected to the system, are free of lead-containing materials or copper-containing materials, as this subsection (g)(1) defines these terms:

A) Lead. To qualify for a SEP granting a full waiver or a partial waiver of the tap water monitoring requirements for lead (i.e., a "lead waiver"), the supplier must provide certification and supporting documentation to the Agency demonstrating that its system is free of all lead-containing materials:

i) The system has no plastic pipes or service lines containing lead plasticizers; and

ii) The system is free of lead service lines, lead pipes, lead soldered pipe joints, and leaded brass- or bronze-alloy fittings and fixtures, unless those fittings and fixtures comply with Section 611.126(b).

BOARD NOTE: Corresponding 40 CFR 141.86(g)(1)(i)(B) specifies "any standard established pursuant to 42 U.S.C. 300g-6(e) (SDWA section 1417(e))". Congress changed the lead standards for fittings and fixtures in the Reduction of Lead in Drinking Water Act, P.L. 111-380, section 2(a)(2) and (b), 124 Stat. 4131 (Jan. 4, 2011). The Board incorporated the statutory changes into this Section by referencing Section 611.126(b).

B) Copper. To qualify for a SEP granting a full waiver or a partial waiver of the tap water monitoring requirements for copper (i.e., a "copper waiver"), the supplier must provide certification and supporting documentation to the Agency demonstrating that its system contains no copper pipes or copper service lines.

2) Monitoring Criteria for Waiver Issuance. The supplier must have completed at least one six-month round of standard tap water monitoring for lead and copper at Agency-approved sites and from the number of sites subsection (c) requires and demonstrate to the Agency that the 90^th percentile concentrations for any and all rounds of monitoring conducted since the system became free of all lead-containing or copper-containing materials, as appropriate, meet certain criteria:

A) Lead Levels. To qualify for a full waiver or a lead partial waiver, the supplier must demonstrate that its 90^th percentile lead concentration does not exceed 0.005 mg/L.

B) Copper Levels. To qualify for a full waiver or a copper partial waiver, the supplier must demonstrate that its 90^th percentile copper concentration does not exceed 0.65 mg/L.

3) Agency Approval of Waiver Application. The Agency must notify the supplier of its waiver determination in a SEP stating the basis of its decision and any condition on the waiver. As a condition on the waiver, the Agency may require the supplier to perform specific activities (e.g., limited monitoring, periodic outreach to customers to remind them to avoid installation of materials that might void the waiver) to avoid the risk of lead or copper concentration of concern in tap water. The supplier must continue monitoring for lead and copper at the tap as subsections (d)(1) through (d)(4) require, as appropriate, until the supplier receives written notification from the Agency approving the waiver.

4) Monitoring Frequency for Suppliers with Waivers

A) A supplier with a full waiver must conduct tap water monitoring for lead and copper under subsection (d)(4)(D) at the reduced number of sampling sites subsection (c) identifies at least once every nine years and provide to the Agency the materials certification subsection (g)(1) specifies for both lead and copper together with the monitoring results. The supplier must collect samples every nine years no later than the ninth calendar year.

B) A supplier with a partial waiver must conduct tap water monitoring for the waived contaminant under subsection (d)(4)(D) at the reduced number of sampling sites subsection (c) specifies at least once every nine years and provide to the Agency the materials certification subsection (g)(1) specifies pertaining to the waived contaminant together with the monitoring results. Such a supplier also must continue to monitor for the non-waived contaminant in under the applicable of subsections (d)(1) through (d)(4).

C) A supplier with a full or partial waiver must notify the Agency in writing under Section 611.360(a)(3) of any upcoming long-term change in treatment or adding a new source, as that rule describes. The Agency must review and approve adding a new source or long-term change in water treatment before the supplier implements it. The Agency may add or modify waiver conditions (e.g., require recertification that the supplier's system is free of lead-containing or copper-containing materials, require additional rounds of monitoring, etc.) if the Agency determines that the modifications are necessary to address system treatment or source water changes.

D) If a supplier with a full or partial waiver becomes aware that its system is no longer free of lead-containing or copper-containing materials, as appropriate (e.g., as a result of new construction or repairs), the supplier must notify the Agency in writing no later than 60 days after becoming aware of the change.

5) Continued Eligibility. If the supplier continues to comply with subsection (g)(4), the waiver will renew automatically, unless any of the conditions in subsections (g)(5)(A) through (g)(5)(C) occur. A supplier whose waiver the Agency revokes may re-apply for a waiver when the supplier again meets the appropriate materials and monitoring criteria of subsections (g)(1) and (g)(2).

A) A full waiver or a lead partial waiver does not renew if the supplier no longer satisfies the materials criteria of subsection (g)(1)(A) or has a 90^th percentile lead concentration greater than 0.005 mg/L.

B) A full waiver or a copper partial waiver does not renew if the supplier no longer satisfies the materials criteria of subsection (g)(1)(B) or has a 90^th percentile copper concentration greater than 0.65 mg/L.

C) A waiver terminates when the Agency notifies the supplier that the Agency revokes the waiver, in writing and describing the basis of its decision.

6) Requirements Following Waiver Revocation. A supplier whose full or partial waiver the Agency revokes must comply with specific corrosion control treatment and lead and copper tap water monitoring requirements:

A) If the supplier exceeds the lead or copper action level, the supplier must implement corrosion control treatment within the deadlines Section 611.351(e) specifies and any other applicable requirements under this Subpart G.

B) If the supplier meets both the lead and the copper action levels, the supplier must monitor for lead and copper at the tap no less frequently than once every three years using the reduced number of sampling sites subsection (c) specifies.

7) Pre-Existing Waivers. A waiver the Agency granted a supplier in writing prior to April 11, 2000 remains in effect under certain conditions:

A) If the supplier demonstrates that its system is free of both lead-containing and copper-containing materials, as subsection (g)(1) requires, and that its 90^th percentile lead and copper concentrations comply with subsection (g)(2), the waiver remains in effect so long as the supplier continues to be eligible for a waiver under subsection (g)(5). The supplier must complete its first round of tap water monitoring under subsection (g)(4) no later than nine years after the supplier last monitored for lead and copper at the tap.

B) If the supplier complies with the materials criteria of subsection (g)(1) but has not complied with the monitoring criteria of subsection (g)(2), the supplier must conduct a round of monitoring for lead and copper at the tap demonstrating that it complied with subsection (g)(2). Thereafter, the waiver remains in effect as long as the supplier complies with the continued eligibility criteria in subsection (g)(5). The supplier must complete its first round of tap water monitoring under subsection (g)(4) no later than nine years after the supplier conducts the monitoring under subsection (g)(2).

h) Follow-Up Samples for “Find-and-Fix” Under Section 611.352(j). A supplier must collect a follow-up sample at any site exceeding the lead action level within 30 days after receiving the sample results. For these follow-up samples, the supplier may use different sample volumes or different sample collection procedures to assess the source of elevated lead. A supplier must submit the results from samples it collects under this Section to the Agency but must not include those results in calculating its 90th percentile concentration.

i) Public Availability of Tap Monitoring Results the Supplier Used in Calculating its 90th Percentile Concentration. A supplier must make the results of its compliance tap water monitoring data, including data the supplier used in calculating its 90th percentile concentration under Section 611.350(c)(4), available to the public within 60 days after the end of the applicable tap sampling period. T his Section does not require a supplier to make publicly available the addresses of the sites where the supplier collected tap samples. A large supplier must make available the monitoring results in a digital format. A small or mid-sized supplier must make available the monitoring results in either a written or digital format. A supplier must retain tap sampling monitoring data per the recordkeeping requirements under Section 611.361.

BOARD NOTE: This Section derives from 40 CFR 141.86.

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