3745-81-12 Maximum contaminant levels and best available technologies for organic contaminants.

(A) The director may determine that a public water system shall apply the following best available technology (BAT), for achieving compliance with the maximum contaminant levels (MCLs) for organic disinfection byproducts identified in this table :

Contaminant

MCL (mg/L)

BAT

Total trihalomethanes

0.080

Enhanced coagulation or enhanced softening plus GAC10; or nanofiltration with a molecular weight of less than or equal to 1000 Daltons; or GAC20

Haloacetic acids (five)

0.060

Enhanced coagulation or enhanced softening plus GAC10; or nanofiltration with a molecular weight of less than or equal to 1000 Daltons; or GAC20

(B) The director may determine that a public water system shall apply the following best technology, treatment techniques or other means available for achieving compliance with the MCLs for TTHM and HAA5 identified in this rule for consecutive systems and applies only to the disinfected water that consecutive systems buy or otherwise receive:

Contaminant

MCL (mg/L)

BAT

Total trihalomethanes

0.080

Systems serving greater than or equal to 10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance. Systems serving less than 10,000: Improved distribution system and storage tank management to reduce residence time.

Haloacetic acids (five)

0.060

Systems serving greater than or equal to 10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance. Systems serving less than 10,000: Improved distribution system and storage tank management to reduce residence time.

(C) The following maximum contaminant levels (MCLs) apply to community public water systems and nontransient noncommunity public water systems. The associated BATs, designated as GAC for granular activated carbon and PTA for packed-tower aeration, identify the best technology, treatment techniques or other means available for achieving compliance with the stated MCLs. The director may determine that a public water system shall apply best available technology in order to reduce the level of a contaminant to below its MCL.

Contaminant

CAS number

MCL (mg/L)

BAT

Vinyl chloride

75-01-4

0.002

PTA

Benzene

71-43-2

0.005

GAC PTA

Carbon tetrachloride

56-23-5

0.005

GAC PTA

p-Dichlorobenzene

106-46-7

0.075

GAC PTA

1,2-Dichloroethane

107-06-2

0.005

GAC PTA

1,1-Dichloroethylene

75-35-4

0.007

GAC PTA

Trichloroethylene

79-01-6

0.005

GAC PTA

1,1,1-Trichloroethane

71-55-6

0.2

GAC PTA

o-Dichlorobenzene

95-50-1

0.6

GAC PTA

cis-1,2-Dichloroethylene

156-59-2

0.07

GAC PTA

trans-1,2-Dichloroethylene

156-60-5

0.1

GAC PTA

1,2-Dichloropropane

78-87-5

0.005

GAC PTA

Dichloromethane

75-09-2

0.005

PTA

Ethylbenzene

100-41-4

0.7

GAC PTA

Monochlorobenzene

108-90-7

0.1

GAC PTA

Styrene

100-42-5

0.1

GAC PTA

Tetrachloroethylene

127-18-4

0.005

GAC PTA

Toluene

108-88-3

1

GAC PTA

1,2,4-Trichlorobenzene

120-82-1

0.07

GAC PTA

1,1,2-Trichloroethane

79-00-5

0.005

GAC PTA

Xylenes (total)

1330-20-7

10

GAC PTA

(D) The following maximum contaminant levels apply to community public water systems and nontransient noncommunity water systems. The associated BATs, designated as GAC for granular activated carbon, PTA for packed-tower aeration, and OX for oxidation with chlorine or ozone, identify the best technology, treatment technique or other means available for achieving compliance with the stated MCLs. The director may determine that a public water system shall apply BAT in order to reduce the level of a contaminant to below its MCL.

Contaminant

CAS number

MCL (mg/L)

BAT

Alachlor

15972-60-8

0.002

GAC

Atrazine

1912-24-9

0.003

GAC

Benzo[a]pyrene

50-32-8

0.0002

GAC

Carbofuran

1563-66-2

0.04

GAC

Chlordane

57-74-9

0.002

GAC

2,4-D

94-75-7

0.07

GAC

Dalapon

75-99-0

0.2

GAC

Dibromochloropropane (DBCP)

96-12-8

0.0002

GAC PTA

Di(2-ethylhexyl) adipate

103-23-1

0.4

GAC

Di(2-ethylhexyl) phthalate

117-81-7

0.006

GAC

Dinoseb

88-85-7

0.007

GAC

Diquat

85-00-7

0.02

GAC

Endothall

145-73-3

0.1

GAC

Endrin

72-20-8

0.002

GAC

Ethylene dibromide (EDB)

106-93-4

0.00005

GAC PTA

Glyphosate

1071-53-6

0.7

OX

Heptachlor

76-44-8

0.0004

GAC

Heptachlor epoxide

1024-57-3

0.0002

GAC

Hexachlorobenzene

118-74-1

0.001

GAC

Hexachlorocyclopentadiene

77-47-4

0.05

GAC PTA

Lindane

58-89-9

0.0002

GAC

Methoxychlor

72-43-5

0.04

GAC

Oxamyl (Vydate)

23135-22-0

0.2

GAC

Picloram

1918-02-1

0.5

GAC

Polychlorinated biphenyls (PCBs)

1336-36-3

0.0005

GAC

Pentachlorophenol

87-86-5

0.001

GAC

Simazine

122-34-9

0.004

GAC

2,3,7,8-TCDD (Dioxin)

1745-01-6

3 x 10-8

GAC

Toxaphene

8001-35-2

0.003

GAC

2,4,5-TP (Silvex)

93-72-1

0.05

GAC

Effective: 4/1/2016
Five Year Review (FYR) Dates: 01/15/2016 and 04/01/2021
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.03, 6109.04
Prior Effective Dates: 12/27/78, 8/24/81, 5/22/89, 9/13/93, 1/1/02, 1/1/10