Effective Date: May 27, 1998

5-1.90 Variance from a maximum contaminant level.

(a) The supplier of water may request, and the department may grant, one or more variances from an MCL contained in sections 5-1.51 and 5-1.52 tables 1, 3, 5 and 7 of this Subpart to any public water system based on a finding that:

(1) because of characteristics of the raw water sources which are reasonably available to it, the public water system cannot meet the requirements respecting such MCL despite application of the best available technology, treatment techniques or other means which are generally available, taking costs into consideration; and

(2) the granting of a variance will not result in an unreasonable risk to health.

(b) At the time of the granting of the variance, the department shall prescribe, and the supplier of water shall follow, a schedule for:

(1) compliance, including increments of progress, to meet each MCL covered by the variance; and

(2) implementation of such control measures as the department may require.

Effective Date: subdivision 5-1.90(c) repealed May 16, 2018

Effective Date: November 01, 2006
2018-01-17 version changed grammar and formatting of (b)

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 sections (b), (c) and (g) of section 5-1.30 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 in which, a waiver of mandatory disinfection treatment for a ground water source may be granted.

Effective Date: August 26, 2020

(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:

Best Available Technologies (BATs)
ContaminantBest Available Technologies
PTA1GAC2OX3
Benzenexx
Carbon tetrachloridexx
1,2-Dichloroethanexx
Trichloroethylenexx
para-dichlorobenzenexx
1,1-Dichloroehylenexx
1,1,1-Trichloroethanexx
Vinyl Chloridex
cis-1,2-Dichloroethanexx
1,2-Dichloropropanexx
Ethylbenzenexx
Monochlorobenzenexx
o-Dichlorobenzenexx
Styrenexx
Tetrachloroethylenexx
Toluenexx
trans-1,2-Dichloroethylenexx
xylenes (total)xx
Alachlorxx
Aldicarbx
Aldicarb sulfoxidex
Aldicarb sulfonex
Atrazinex
Carbofuranx
Chlordanex
Dibromochloropropanexx
2,4-Dx
Ethylene dibromidexx
Heptachlorx
Heptachlor epoxidex
Lindanex
Methoxychlorx
PCBsx
Pentachlorophenolx
Perfluorooctanesulfonic acid (PFOS)x
Perfluorooctanonic acid (PFOA)x
Toxaphenex
2,4,5-TPx
Benzo(a)pyrenex
Dalaponx
Dichloromethanex
Di (2-ethyhexyl) adipatexx
Di (2-ethyhexyl) phthalatex
Dinosebx
1,4-Dioxanex
Diquatx
Endothallx
Endrinx
Glyphosatex
Hexachlorobenzenex
Hexachlorocyclopentadienexx
Oxamyl (Vydate)x
Pichloramx
Simazinex
1,2,4-Trichlorobenzenexx
1,1,2-Trichloroethanexx
2,3,7,8-TCDD (Dioxin)x
TTHM, HAA5,Bromate, Chlorite4
1Packed Tower Aeration
2Granular Activated Carbon
3Oxidation (Chlorination or Ozonation) and Advanced Oxidation Proces (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.

Effective Date: May 16, 2018

(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 listed in 5-1.52 tables 1 and 7 of this Subpart:

Chemical nameBAT(s)
Antimony2,7
Arsenic51,2,5,6,7,9,136
Asbestos2,3,8
Barium5,6,7,9
Beryllium1,2,5,6,7
Cadmium2,5,6,7
Chromium2,5,62,7
Cyanide5,7,10
Fluoride1,7
Mercury21,4,61,71
Nickel5,6,7
Nitrate5,7
Nitrite5,6,9
Selenium1,23,6,7,9
Thallium1,5
Gross alpha (exluding radon and uranium)7
Combined radium (226 and 228)5,6,7
Uranium5,6,7,124
Beta particle and photon activity5,7
1BAT only if influent Hg concentrations less than or equal 10 micrograms per liter
2BAT for Chromium III only.
3BAT for Selenium IV only.
4Assumes that the system already has coagulation/filtration in place
5BATs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
6To obtain high removals, iron to arsenic ratio must be at least 20:1.

Key to Best Available Technologies (BATs) in Table
1 = Activated Alumina
2 = Coagulation/Filtration (not BAT for systems <500 service connections)
3 = Direct and Diatomite Filtration
4 = Granular Activated Carbon
5 = Ion Exchange
6 = Lime Softening (not BAT for systems <500 service connections)
7 = Reverse Osmosis
8 = Corrosion Control
9 = Electrodialysis
10 = Chlorine
11 = Ultraviolet
12 = Enhanced coagulation/filtration
13 = Oxidation/Filtration

(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:

Technology for Arsenic MCL Compliance at Systems Serving ≤ 10,0000
Small system compliance technology1Affordable for listed small system categories
Activated Alumina (centralized)All Systems Serving 25-10,000
Activated Alumina (Point-of-Use)2All Systems Serving 25-10,000
Coagulation/Filtration3Systems Serving 501-10,000
Coagulation-assisted MicrofiltrationSystems Serving 501-10,000
Electrodialysis reversal4Systems Serving 501-10,000
Enhanced coagulation/filtrationAll Systems Serving 25-10,000
Enhanced lime softening (pH > 10.5)All Systems Serving 25-10,000
Ion ExchangeAll Systems Serving 25-10,000
Lime Softening3Systems Serving 501-10,000
Oxidation/Filtration5All Systems Serving 25-10,000
Reverse Osmosis (centralized)4Systems Serving 501-10,000
Reverse Osmosis (Point-of-Use)2All Systems Serving 25-10,000

1Small System Compliance Technologies for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
2When point-of-use or point-of-entry devices are used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be provided by the water system to ensure adequate performance.
3Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed.
4May not be appropriate for areas where water quantity may be an issue.
5To obtain high removals, iron to arsenic ratio must be at least 20:1.

Effective Date: May 26, 2004?

(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.

Effective Date: May 16, 2018

5-1.92 Exemption from a maximum contaminant level or any treatment technique requirement.

(a) The supplier of water may request, and the department may grant, one or more exemptions from any treatment technique requirement, except for disinfection of a surface water source, and/or any MCL, except for Escherichia coli (E. coli). Exemptions may be granted to any public water system based on a finding that:

Effective Date: January 17, 2018

(1) because of compelling factors which may include economic factors, the public water system is unable to comply with such MCL or treatment technique requirement;

(2) the public water system was in operation on the effective date of such MCL or treatment technique requirement; and

(3) the granting of an exemption will not result in an unreasonable risk to health.

(b) Exemptions, if granted, will be issued with a mandatory compliance strategy to include but not be limited to the following:
(1) a specific time which to achieve compliance, including increments of progress to meet the MCL or treatment technique covered by the exemption;

(2) control measures as the department may require to ensure the public health; and

(3) appropriate modifications and/or improvements to the existing system or facility as may be necessary for the system or facility to fully conform to the requirements of this Subpart.

(c) Such schedule prescribed by the department pursuant to subdivision (b) of this section shall require compliance with each MCL or treatment technique requirement no later than twelve months after the issuance of the exemption.

(d) The final date for compliance provided in any schedule in the case of any exemption may be extended by the State for a period not to exceed three years after the date of the issuance of the exemption if the public water system establishes that:

(1) the system cannot meet the standard without capital improvements which cannot be completed within the period of such exemption;

(2) in the case of a system which needs financial assistance for the necessary improvements, the system has entered into an agreement to obtain such financial assistance; or

(3) the system has entered into an enforceable agreement to become a part of a regional public water system and the system is taking all practical steps to meet the standard.

(e) In the case of a system which serves a population of no more than 3,300 and which needs financial assistance for the necessary improvements, an exemption granted under subdivision (1) or (2) of subdivision (a) of this section may be renewed for one or more additional two-year periods, not to exceed six years, if the system establishes that it is taking all practical steps to meet the requirements of subdivision (a) of this section.

Effective Date: March 11, 1992

5-1.93 Variance or exemption requests.

(a) All requests for a variance or an exemption shall be in a form prescribed by and submitted in writing to the department. Suppliers of water may submit a joint request for variances or exemptions when they seek similar variances or exemptions under similar circumstances. The department shall act on any request for a variance or an exemption submitted pursuant to section 5-1.90, 5-1.91 or 5-1.92 of this Subpart within 90 days of receipt of the request.

(b) Requests for exemptions to the filtration requirements outlined in subdivision (b) of section 5-1.30 of this Subpart must be made by June 29, 1992, except for systems with ground water sources determined to be directly influenced by surface water. For systems with ground water sources directly influenced by surface water the request for an exemption must be submitted no later than six months after notification of the determination of direct influence. Before an exemption to a filtration requirement can be granted, the supplier of water must demonstrate to the department that the granting of the exemption will not pose an unreasonable risk to public health and that the system is in compliance with paragraphs (5) and (8) of subdivision (c) of sections 5-1.30 of this Subpart, subdivision (g) of section 5-1.30 of this Subpart and section 5-1.52 tables 3, 6, 9 and 11 of this Subpart.

(c) Systems with unfiltered surface water sources or ground water sources directly influenced by surface water must have a disinfection capability that achieves at least 99 percent inactivation of Giardia lamblia cysts before an exemption to a filtration requirement can be granted.

Effective Date: January 17, 2018

5-1.94 Notice and opportunity for public hearing.

(a) Before a variance proposed to be granted by the department under section 5-1.90 or 5-1.91 of this Subpart may take effect, the department shall provide notice and opportunity for public hearing on the proposed variance. A notice given pursuant to the preceding sentence may cover the granting of more than one variance and a hearing held pursuant to such notice shall include each of the variances covered by the notice.

(b) Before a compliance or implementation schedule prescribed by the department pursuant to the granting of a variance under section 5-1.90 of this Subpart or an exemption under section 5-1.92 of this Subpart may take effect, the department shall provide notice and opportunity for public hearing on the proposed compliance or implementation schedule, or both. A notice given pursuant to the preceding sentence may cover the proposal of more than one such schedule and a hearing held pursuant to such notice shall include each of the schedules covered by the notice.

(c) Public notice of an opportunity for hearing pursuant to subdivision (a) or (b) of this section shall be circulated in a manner designated to inform potentially interested persons of the proposed action. Requests for hearing shall be submitted to the department within 15 days after issuance of such public notice.

(d) Notice of public hearings to be held pursuant to request submitted by an interested person or on the department's own motion shall be given not less than 30 days before the time scheduled for the hearing, in a form and manner to be prescribed by the department. Notices of public hearing shall be circulated in a manner designed to inform interested persons of the hearing.

(e) If no timely request for hearing is submitted and the department does not determine to hold a public hearing on his own motion, the proposed variance or schedule prescribed pursuant to the granting of a variance or exemption shall become effective 30 days after notice of opportunity for hearing is given pursuant to subdivision (c) of this section. If a public hearing is held, the department shall take an action with respect to such proposed variance or schedule within 30 days after the end of the public hearing.

Effective Date: January 6, 1993 (or before - last seen in 1981 code)

5-1.95 (Reserved)

Effective Date: May 27, 1998

5-1.96 Enforceability of final schedule prescribed pursuant to granting of variance or exemption.

Once a schedule prescribed pursuant to the granting of a variance under section 5-1.90 of this Subpart or an exemption under section 5-1.92 of this Subpart has become final pursuant to subdivision (e) of section 5-1.94 of this Subpart, the conditions or requirements of any such schedule shall be enforceable, on the application of the Commissioner, by any court of competent jurisdiction in the same manner as an order of the Commissioner under section 1107 of the Public Health Law.

Effective Date: June 24, 1977

5-1.100 Separability.

If any provisions of this Part are held invalid, such invalidity shall not affect other provisions which can be given effect without the invalid provisions.