Monitoring for the purpose of determining compliance with Regulation .06 of this chapter shall be conducted by the supplier of water to a community water system, nontransient noncommunity water system, and transient noncommunity water system in accordance with the requirements of 40 CFR §141.23(a)(1)—(3). Routine Monitoring Frequency. A supplier of water to a community surface or combined surface and ground water system and a supplier of water to a nontransient noncommunity surface or combined surface and ground water system shall: Monitor each entry point annually for the contaminants listed in Regulation .06A(1), (2), (4)—(11), (14), and (15) of this chapter; Monitor each entry point quarterly for nitrates, although a supplier may reduce the frequency to annual monitoring for nitrates if the results from four consecutive quarters, collected after January 1, 1993, are all less than 50 percent of the MCL; Collect the annual sample required by §B(1)(b) of this regulation during the quarter which previously yielded the highest analytical result; Return to quarterly monitoring for nitrates if any annual sample is greater than 50 percent of the MCL; Monitor each entry point once for nitrites; and Collect follow-up nitrite analysis in accordance with 40 CFR §141.23(e)(3)—(4), if the first was equal to or greater than 50 percent of the nitrite MCL. A supplier of water to a community and nontransient noncommunity ground water system shall: Monitor each entry point once every 3 years for the contaminants listed in Regulation .06A(1), (2), (4)—(11), (14) and (15) of this chapter; Monitor each entry point annually for nitrates; Increase nitrate monitoring frequency to quarterly for at least 1 year following any sample which is 50 percent or greater than the MCL, although a supplier of water may return to annual nitrate sampling if the Approving Authority determines that the results are reliably and consistently less than the MCL for at least 4 consecutive quarters; Collect the annual sample required by §B(2)(c) of this regulation during the quarter which previously yielded the highest analytical result; Monitor each entry point once for nitrites before December 31, 1995; and Collect follow up nitrite analysis in accordance with 40 CFR §141.23(e)(3)—(4) if the first test was equal to or greater than 50 percent of the MCL. Notwithstanding §B(1) and (2) of this regulation, a supplier of water to a nontransient noncommunity water system is not required to monitor for fluoride. A supplier of water to a transient noncommunity water system shall monitor: Annually for nitrates; and Once for nitrites and, if the nitrite result is equal to or greater than 50 percent of the MCL, the supplier of water shall conduct repeat testing in accordance with 40 CFR §141.23(e)(3)—(4). Asbestos. In this subsection, “corrosive finished water” includes but is not limited to water provided by a water supplier who fails to meet the treatment technique requirements of 40 CFR §§141.81 or 141.82. A supplier of water to a community or nontransient noncommunity water system is vulnerable to asbestos contamination and shall conduct an analysis for asbestos if the: Supplier's well is constructed in asbestos-bearing rock; Supplier's surface source is subject to asbestos contamination; or Supplier has asbestos concrete pipe in its distribution system and has corrosive finished water. The frequency and location of monitoring for asbestos by systems vulnerable to asbestos shall be in accordance with the requirements of 40 CFR §141.23(b)(1) and (5)—(10), which is incorporated by reference. If the Approving Authority determines that a system is not vulnerable to asbestos contamination, the supplier of water may receive a waiver from all testing for asbestos. Cyanide. The Approving Authority may grant a waiver to a supplier of water to a community or nontransient noncommunity water system from all testing for cyanide if the Approving Authority determines that the system is not vulnerable to cyanide contamination due to lack of any industrial sources of cyanide that could contribute cyanide to the water system. The Approving Authority may designate a time during each compliance period that a supplier of water to a public water system shall monitor, and this supplier of water shall monitor during the time designated. Suppliers of water at all systems that begin operation after January 22, 2004 or at systems that begin use of a new source of water after January 22, 2004 shall: Demonstrate compliance with the MCLs for contaminants listed in Regulation .06A of this chapter within a period of time specified by the Approving Authority; Comply with the initial sampling frequencies specified by the Approving Authority to ensure a system can demonstrate compliance with the MCLs; and Conduct routine and increased monitoring frequencies in accordance with the requirements in this regulation. The monitoring frequencies under §§B and F of this regulation are minimum requirements and may be increased at the discretion of the Approving Authority. A supplier of water to a public water system may reduce the number of samples to be analyzed by the use of compositing. Compositing shall be performed according to the requirements of 40 CFR §141.23(a)(4). Waivers. The Approving Authority may grant a waiver from the requirements of §B(1)(a) and (2)(a) of this regulation to a supplier of water. A waiver of §B(1)(a) and (2)(a) of this regulation may not exceed 9 years, and at least one sample is required to be collected during the term of the waiver. The Approving Authority shall follow the requirements of 40 CFR §141.23(b)(4) and (c)(4)—(6), when evaluating and issuing a waiver. Repeat Monitoring When Results Exceed MCLs. A supplier of water shall: Collect and analyze a second sample from each sampling point at which a routine sample exceeded a maximum contaminant level for the contaminants listed in Regulation .06A(1) and (3)—(16) of this chapter; and Comply with the requirements of 40 CFR §141.23(m) and (n), which is incorporated by reference, when a routine sample exceeds the maximum contaminant level for arsenic. For all contaminants listed in Regulation .06A of this chapter except nitrates and nitrites, if the results of sampling indicate an exceedance of the MCL, the Approving Authority may require that one additional sample be collected as soon as possible after the initial sample was taken, but not to exceed 2 weeks, at the same sampling point. A supplier of water shall collect and analyze a second sample for nitrates, nitrites, or total nitrates plus nitrites within 24 hours of being notified that a routine sample exceeded an MCL for nitrates, nitrites, or total nitrates plus nitrites. A supplier of water shall monitor on a quarterly frequency from each sampling point that has been determined to exceed a maximum contaminant level for the contaminants listed in Regulation .06A(1)—(11), (14), and (15) of this chapter, as determined by §G of this regulation. The Approving Authority may decrease the quarterly monitoring testing required in §F(4) of this regulation in accordance with the requirements of 40 CFR §141.23(c)(8). Compliance Determination and Notification. The average of the results from routine and confirmation samples shall be used to determine compliance. Compliance with maximum contaminant levels shall be determined in accordance with 40 CFR §141.23(f)(3) and(i). The Approving Authority may delete results from obvious sampling errors. A supplier of water that does not collect the repeat sample within the time frame required by §F(3) of this regulation shall: Immediately notify the Approving Authority and also notify the consumers served by the system in accordance with Regulation .20 of this chapter; Take and analyze a confirmation sample within 2 weeks of notification of the analytical results of the first sample; and For nitrate or nitrite sampling, comply with Tier 1 public notice requirements set forth in Regulation .20(J) of this chapter, and immediately notify individuals served by the public water system. A supplier of water that has exceeded a maximum contaminant level in Regulation .06A of this chapter, as determined by §G(1) of this regulation, shall notify the Approving Authority as required by Regulation .19 of this chapter and give public notice as required by Regulation .20 of this chapter. Arsenic sampling results shall be reported to the nearest 0.001 milligrams per liter (mg/l). Monitoring and analysis conducted to determine compliance with Regulation .06A of this chapter shall be made in accordance with approved methods and procedures cited in 40 CFR §141.23(k). Suppliers of water may be eligible for variances or exemptions from the maximum contaminant levels for inorganic chemicals based on criteria outlined in 40 CFR §142.62.