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

Effective Date

01/17/2018

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 filtrationand 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 water source 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:

BEST AVAILABLE TECHNOLOGIES (BATs)

Best Available Technologies

Contaminant
PTA1 GAC2 OX3
Benzene X X
Carbon tetrachloride X X
1,2-Dichloroethane X X
Trichloroethylene X X
para-Dichlorobenzene X X
1,1-Dichloroethylene X X
1,1,1-Trichloroethane X X
Vinyl chloride X
cis-1,2-Dichloroethylene X X
1,2-Dichloropropane X X
Ethylbenzene X X
Monochlorobenzene X X
o-Dichlorobenzene X X
Styrene X X
Tetrachloroethylene X X
Toluene X X
trans-1,2-Dichloroethylene X X
Xylenes (total) X X
Alachlor X
Aldicarb X
Aldicarb sulfoxide X
Aldicarb sulfone X
Atrazine X
Carbofuran X
Chlordane X
Dibromochloropropane X X
2,4-D X
Ethylene dibromide X X
Heptachlor X
Heptachlor epoxide X
Lindane X
Methoxychlor X
PCBs X
Pentachlorophenol X
Toxaphene X
2,4,5-TP X
Benzo(a)pyrene X
Dalapon X
Dichloromethane X
Di(2-ethylhexyl)adipate X X
Di(2-ethylhexyl)phthalate X
Dinsoeb X
Endothal X
Endrin X
Glyphosate x
Hexachlorobenzene X
Hexachlorocyclopentadiene X X
Oxamyl (Vydate) X
Picloram X
Simazine X
1,2,4-Trichlorobenzene X X
1,1,2-Trichloroethane X X
2,3,7,8-TCDD (Dioxin) X
TTHM, HAA5, Bromate, Chlorite4  
   

 

1Packed Tower Aeration

2Granular Activated Carbon

3Oxidation (Chlorination or Ozonation)

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 listed in section 5-1.52, Tables 1 and 7 of this Subpart:

 

Technologies for Achieving MCL Compliance

Chemical Name

Best Available Technologies

Antimony

2,7

Arsenic5

1,2,5,6,7,9,136

Asbestos

2,3,8

Barium

5,6,7,9

Beryllium

1,2,5,6,7

Cadmium

2,5,6,7

Chromium

2,5,62,7

Cyanide

5,7,10

Fluoride

1,7

Mercury (Hg)

21,4,61,71

Nickel

5,6,7

Nitrate

5,7

Nitrite

5,7, 9

Selenium

1,23,6,7,9

Thallium

1,5

Gross alpha (excluding radon and uranium)

7

Combined radium (226 and 228)

5,6,7

Uranium

5,6,7,124

Beta particle and photon radioactivity

5,7

 

1BAT only if influent Hg concentrations <10 µg/L.

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 ≤10,000

Small system compliance technology1

Affordable for listed small  system categories

Activated Alumina (centralized)

All Systems Serving 25-10,000

Activated Alumina (Point-of-Use)2

All Systems Serving 25-10,000

Coagulation/Filtration3

Systems Serving 501-10,000

Coagulation-assisted Microfiltration

Systems Serving 501-10,000

Electrodialysis reversal4

Systems Serving 501-10,000

Enhanced coagulation/filtration

All Systems Serving 25-10,000

Enhanced lime softening (pH > 10.5)

All Systems Serving 25-10,000

Ion Exchange

All Systems Serving 25-10,000

Lime Softening3

Systems Serving 501-10,000

Oxidation/Filtration5

All Systems Serving 25-10,000

Reverse Osmosis (centralized)4

Systems Serving 501-10,000

Reverse Osmosis (Point-of-Use)2

All 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 longterm 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.

 

(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 stem 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.

Volume

VOLUME A (Title 10)

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