Md. Code Regs. 26.04.01.07 : DEPARTMENT OF ENVIRONMENT — SUBTITLES 01-07 — REGULATION OF WATER SUPPLY, SEWAGE DISPOSAL, SOLID WASTE, AND RECYCLABLE MATERIALS — Quality of Drinking Water in Maryland — Maximum Contaminant Levels for Organic Chemicals in Drinking Water

A. Suppliers of water to community water systems and nontransient noncommunity water systems shall comply with the MCLs for organic chemicals in §§D, E, and F of this regulation.
B. Maximum Contaminant Levels for Total Trihalomethanes. Community and nontransient noncommunity Subpart H systems serving 10,000 or more individuals shall comply with §F(1)-(4) of this regulation beginning January 1, 2002. Community and nontransient noncommunity Subpart H systems serving fewer than 10,000 individuals and systems using only ground water not under the direct influence of surface water shall comply with §F(1)-(4) of this regulation beginning January 1, 2004. All water systems shall comply with these MCLs until the date specified in Regulation .15-2I(2)(b) of this chapter.
C. MCLs for organic chemicals are shown in §§D-F of this regulation.
D. Volatile Organic Contaminants.

Contaminant Maximum
Contaminant
Level (mg/l)
(1) Vinyl chloride 0.002
(2) Benzene 0.005
(3) Carbon tetrachloride 0.005
(4) 1,2-Dichloroethane 0.005
(5) Trichloroethylene 0.005
(6) para-Dichlorobenzene 0.075
(7) 1,1-Dichloroethylene 0.007
(8) 1,1,1-Trichloroethane 0.2
(9) cis-1,2-Dichloroethylene 0.07
(10) 1-2,-Dichloropropane 0.005
(11) Ethylbenzene 0.7
(12) Monochlorobenzene 0.1
(13) o-Dichlorobenzene 0.6
(14) Styrene 0.1
(15) Tetrachloroethylene 0.005
(16) Toluene 1
(17) trans-1,2-Dichloroethylene 0.1
(18) Xylenes (total) 10
(19) Dichloromethane 0.005
(20) 1,2,4-Trichlorobenzene 0.07
(21) 1,1,2-Trichloroethane 0.005

E. Synthetic Organic Contaminants.

Contaminant MaximumContaminant
Level (mg/l)
(1) Alachlor 0.002
(2) Atrazine 0.003
(3) Carbofuran 0.04
(4) Chlordane 0.002
(5) Dibromochloropropane 0.0002
(6) 2,4-D 0.07
(7) Ethylene dibromide 0.00005
(8) Haptachlor 0.0004
(9) Heptachlor epoxide 0.0002
(10) Lindane 0.0002
(11) Methoxychlor 0.04
(12) Polychlorinated biphenyls 0.0005
(13) Pentachlorophenol 0.001
(14) Toxaphene 0.003
(15) 2,4,5-TP 0.05
(16) Benzo(a)pyrene 0.0002
(17) Dalapon 0.2
(18) Di(2-ethylhexyl)adipate 0.4
(19) Di(2-ethylhexyl)phthalate 0.006
(20) Dinoseb 0.007
(21) Diquat 0.02
(22) Endothall 0.1
(23) Endrin 0.002
(24) Glyphosate 0.7
(25) Hexachlorobenzene 0.001
(26) Hexachlorcyclopentadiene 0.05
(27) Oxamyl (vydate) 0.2
(28) Picloram 0.5
(29) Simazine 0.004
(30) 2,3,7,8-TCDD (dioxin) 3x10-8

F. Disinfection Byproducts Maximum Contaminant Levels.
(1) Total trihalomethanes (TTHM) 0.080 mg/l
(2) Haloacetic acids (five) (HAA5) 0.060 mg/l
(3) Bromate ... 0.010 mg/l
(5) Chlorite ... 1.0 mg/l

Md. Code Regs. 26.04.01.07

Regulations .07 amended effective August 10, 1987 (14:16 Md. R. 1774)
Regulation .07 amended effective December 14, 2009 (36:25 Md. R. 1956)