--- kind: "section" citation: "40 C.F.R. § 141.6" title: "40" number: "141.6" heading: "Effective dates." url: "https://uscodex.org/cfr/40/141.6" --- # §141.6. Effective dates. - (a) Except as provided in [paragraphs (b) through (l)](#b..l) of this section the regulations set forth in this part take effect on June 24, 1977. - (b) The regulations for total trihalomethanes set forth in [§ 141.12(c)](/cfr/40/141.12.md?p=c) shall take effect 2 years after the date of promulgation of these regulations for community water systems serving 75,000 or more individuals, and 4 years after the date of promulgation for communities serving 10,000 to 74,999 individuals. - (c) The regulations set forth in [§§ 141.11(d)](/cfr/40/141.11.md?p=d); 141.21(a), (c) and (i); 141.22(a) and (e); 141.23(a)(3) and (a)(4); 141.23(f); 141.24(e) and (f); 141.25(e); 141.27(a); 141.28(a) and (b); 141.31(a), (d) and (e); 141.32(b)(3); and 141.32(d) shall take effect immediately upon promulgation. - (d) The regulations set forth in [§ 141.41](/cfr/40/141.41.md) shall take effect 18 months from the date of promulgation. Suppliers must complete the first round of sampling and reporting within 12 months following the effective date. - (e) The regulations set forth in [§ 141.42](/cfr/40/141.42.md) shall take effect 18 months from the date of promulgation. All requirements in [§ 141.42](/cfr/40/141.42.md) must be completed within 12 months following the effective date. - (f) The regulations set forth in [§ 141.11(c)](/cfr/40/141.11.md?p=c) and [§ 141.23(g)](/cfr/40/141.23.md?p=g) are effective May 2, 1986. [Section 141.23(g)(4)](/cfr/40/141.23.md?p=g-4) is effective October 2, 1987. - (g) The regulations contained in § 141.6, [paragraph (c)](#c) of the table in §§ [141.12](/cfr/40/141.12.md), and [141.62(b)(1)](/cfr/40/141.62.md?p=b-1) are effective July 1, 1991. The regulations contained in §§ [141.11(b)](/cfr/40/141.11.md?p=b), [141.23](/cfr/40/141.23.md), [141.24](/cfr/40/141.24.md), [142.57(b)](/cfr/40/142.57.md?p=b), [143.4(b)(12)](/cfr/40/143.4.md?p=b-12) and [(b)(13)](/cfr/40/143.4.md?p=b-13), are effective July 30, 1992. The regulations contained in the revisions to [§§ 141.32(e)](/cfr/40/141.32.md?p=e) (16), (25) through (27) and (46); 141.61(c)(16); and 141.62(b)(3) are effective January 1, 1993. The effective date of regulations contained in [§ 141.61(c)](/cfr/40/141.61.md?p=c) (2), (3), and (4) is postponed. - (h) Regulations for the analytic methods listed at [§ 141.23(k)(4)](/cfr/40/141.23.md?p=k-4) for measuring antimony, beryllium, cyanide, nickel, and thallium are effective August 17, 1992. Regulations for the analytic methods listed at [§ 141.24(f)(16)](/cfr/40/141.24.md?p=f-16) for dichloromethane, 1,2,4-trichlorobenzene, and 1,1,2-trichloroethane are effective August 17, 1992. Regulations for the analytic methods listed at [§ 141.24(h)(12)](/cfr/40/141.24.md?p=h-12) for measuring dalapon, dinoseb, diquat, endothall, endrin, glyphosate, oxamyl, picloram, simazine, benzo(a)pyrene, di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, hexachlorobenzene, hexachlorocyclopentadiene, and 2,3,7,8-TCDD are effective August 17, 1992. The revision to [§ 141.12(a)](/cfr/40/141.12.md?p=a) promulgated on July 17, 1992 is effective on August 17, 1992. - (i) [Reserved] - (j) The arsenic maximum contaminant levels (MCL) listed in [§ 141.62](/cfr/40/141.62.md) is effective for the purpose of compliance on January 23, 2006. Requirements relating to arsenic set forth in §§ [141.23(i)(4)](/cfr/40/141.23.md?p=i-4), [141.23(k)(3)](/cfr/40/141.23.md?p=k-3) introductory text, 141.23(k)(3)(ii), 141.51(b), 141.62(b), 141.62(b)(16), 141.62(c), 141.62(d), and 142.62(b) revisions in appendix A of [subpart O](/cfr/40/subpartO.md) for the consumer confidence rule, and appendices A and B of [subpart Q](/cfr/40/subpartQ.md) for the public notification rule are effective for the purpose of compliance on January 23, 2006. However, the consumer confidence rule reporting requirements relating to arsenic listed in § [141.154(b)](/cfr/40/141.154.md?p=b) and [(f)](/cfr/40/141.154.md?p=f) are effective for the purpose of compliance on February 22, 2002. - (k) Regulations set forth in §§ [141.23(i)(1)](/cfr/40/141.23.md?p=i-1), [141.23(i)(2)](/cfr/40/141.23.md?p=i-2), [141.24(f)(15)](/cfr/40/141.24.md?p=f-15), [141.24(f)(22)](/cfr/40/141.24.md?p=f-22), [141.24(h)(11)](/cfr/40/141.24.md?p=h-11), [141.24(h)(20)](/cfr/40/141.24.md?p=h-20), [142.16(e)](/cfr/40/142.16.md?p=e), [142.16(j)](/cfr/40/142.16.md?p=j), and [142.16(k)](/cfr/40/142.16.md?p=k) are effective for the purpose of compliance on January 22, 2004. - (l) The regulations pertaining to the per- and polyfluoroalkyl substances (PFAS) chemicals set forth in [subpart Z](/cfr/40/subpartZ.md) of this part are effective June 25, 2024. See [§ 141.900](/cfr/40/141.900.md) for the compliance dates for provisions under subpart Z. Compliance with reporting requirements under [subpart Z](/cfr/40/subpartZ.md), in accordance with [subparts O](/cfr/40/subpartO.md) (the consumer confidence rule) and Q (the public notification rule) of this part are required on April 26, 2027, except for notification requirements in [§ 141.203](/cfr/40/141.203.md) related to violations of the MCLs. The compliance date for the PFAS MCLs in [§ 141.61](/cfr/40/141.61.md), as specified in [§ 141.60](/cfr/40/141.60.md), and for [§ 141.203](/cfr/40/141.203.md) notifications of violations of the PFAS MCLs is April 26, 2029. ## Notes ### Amendments [44 FR 68641, Nov. 29, 1979, as amended at 45 FR 57342, Aug. 27, 1980; 47 FR 10998, Mar. 12, 1982; 51 FR 11410, Apr. 2, 1986; 56 FR 30274, July 1, 1991; 57 FR 22178, May 27, 1992; 57 FR 31838, July 17, 1992; 59 FR 34322, July 1, 1994; 61 FR 24368, May 14, 1996; 66 FR 7061, Jan. 22, 2001; 66 FR 28350, May 22, 2001; 89 FR 32744, Apr. 26, 2024] ### Authority Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11. ### Source Source: 40 FR 59570, Dec. 24, 1975, unless otherwise noted. ### Amendments [44 FR 68641, Nov. 29, 1979, as amended at 45 FR 57342, Aug. 27, 1980; 47 FR 10998, Mar. 12, 1982; 51 FR 11410, Apr. 2, 1986; 56 FR 30274, July 1, 1991; 57 FR 22178, May 27, 1992; 57 FR 31838, July 17, 1992; 59 FR 34322, July 1, 1994; 61 FR 24368, May 14, 1996; 66 FR 7061, Jan. 22, 2001; 66 FR 28350, May 22, 2001; 89 FR 32744, Apr. 26, 2024]