N.Y. Comp. Codes R. & Regs. Tit. 10 §§ 5-1.91

Current through Register Vol. 46, No. 50, December 11, 2024

Section 5-1.91 - Variance from required use of any specified treatment technique

(a) The supplier of water may request, and the department may grant, one or more variances from any treatment technique requirement, except filtration and disinfection, in accordance with section 5-1.30(b), (c) and (g) of this Subpart on a finding that such treatment technique is not necessary to protect the health of persons served by the public water system because of the raw water source or sources of such system.

(b) As a condition to the granting of a variance under subdivision (a) of this section, the supplier of water shall perform monitoring and other requirements as prescribed by the department.

(c) Notwithstanding subdivisions (a) and (b) of this section, section 5-1.30 of this Subpart shall govern the conditions under, and the manner which, a waiver of mandatory disinfection treatment for a ground source of water supply may be granted.

(d) The technologies listed in this section are the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for organic chemicals listed in section 5-1.52 table 3 of this Subpart:

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¹Packed Tower Aeration 2Granular Activated Carbon

³Oxidation (Chlorination or Ozonation) and Advanced Oxidation Process (AOP)

⁴For surface water systems or ground water systems influenced by surface water, GAC10, as defined in section 5-1.1 of this Subpart, is the BAT for compliance with the TTHM and HAA5 MCL as a Running Annual Average (RAA). The other BAT for RAA compliance is enhanced coagulation for TTHM and HAA5 precursor removal, as described in section 5-1.60 of this Subpart. For compliance with the MCLs for TTHM and HAA5 as LRAAs, the following are the BATs: enhanced coagulation or enhanced softening, plus GAC10; GAC20, as defined in section 5-1.1 of this Subpart; or nanofiltration with a molecular weight cutoff less than or equal to 100 Daltons. Refer to section 5-1.65 of this Subpart for BATs for TTHM, HAA5, Bromate, and Chlorite.

(e) The following are the best technologies, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for the inorganic chemicals and radionuclides in section 5-1.52, tables 1 and 7 of this Subpart:

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(f) The following are the affordable technologies, treatment techniques, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the MCL for arsenic as listed in section 5-1.52 table 1 of this Subpart:

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(g) The community water systems and nontransient noncommunity water systems must install and/or use any treatment method identified in subdivisions (d) and (e) of this section as a condition for granting a variance except as provided in subdivision (h) of this section. If after the system's installation of the treatment method, the system cannot meet the MCL, that system shall be eligible for a variance.

(h) If a system can demonstrate through comprehensive engineering assessments, which may include pilot plant studies, that the treatment methods identified in subdivisions (d) and (e) of this section would only achieve a de minimis reduction in contaminants, the State may issue a schedule of compliance that requires the system being granted the variance to examine other treatment methods as a condition of obtaining the variance.

(i) If the State determines that a treatment method identified in subdivision (g) of this section is technically feasible, the State may require the system to install and/or use that treatment method in connection with a compliance schedule. The State's determination shall be based upon studies by the system and other relevant information.

N.Y. Comp. Codes R. & Regs. Tit. 10 §§ 5-1.91

Amended New York State Register January 17, 2018 /Volume XL, Issue 03, eff. 1/17/2018

Amended New York State Register August 26, 2020/Volume XLII, Issue 34, eff. 8/26/2020