(a) The following maximum contaminant levels for volatile organic contaminants apply to community and non-transient, non-community water systems.
Table 1 to Paragraph (a)—Maximum Contaminant Levels for Volatile Organic Contaminants
CAS No.
| Contaminant
| MCL (mg/l)
|
---|
(1) 75-01-4 | Vinyl chloride | 0.002
|
(2) 71-43-2 | Benzene | 0.005
|
(3) 56-23-5 | Carbon tetrachloride | 0.005
|
(4) 107-06-2 | 1,2-Dichloroethane | 0.005
|
(5) 79-01-6 | Trichloroethylene | 0.005
|
(6) 106-46-7 | para-Dichlorobenzene | 0.075
|
(7) 75-35-4 | 1,1-Dichloroethylene | 0.007
|
(8) 71-55-6 | 1,1,1-Trichloroethane | 0.2
|
(9) 156-59-2 | cis-1,2-Dichloroethylene | 0.07
|
(10) 78-87-5 | 1,2-Dichloropropane | 0.005
|
(11) 100-41-4 | Ethylbenzene | 0.7
|
(12) 108-90-7 | Monochlorobenzene | 0.1
|
(13) 95-50-1 | o-Dichlorobenzene | 0.6
|
(14) 100-42-5 | Styrene | 0.1
|
(15) 127-18-4 | Tetrachloroethylene | 0.005
|
(16) 108-88-3 | Toluene | 1
|
(17) 156-60-5 | trans-1,2-Dichloroethylene | 0.1
|
(18) 1330-20-7 | Xylenes (total) | 10
|
(19) 75-09-2 | Dichloromethane | 0.005
|
(20) 120-82-1 | 1,2,4-Trichloro- benzene | .07
|
(21) 79-00-5 | 1,1,2-Trichloro- ethane | .005 |
(b) The Administrator, pursuant to section 1412 of the Act, hereby identifies as indicated in table 2 to this paragraph (b) granular activated carbon (GAC), packed tower aeration (PTA), or oxidation (OX) as the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c) of this section, except for per- and polyfluoroalkyl substances (PFAS).
Table 2 to Paragraph (b)—BAT for Organic Contaminants in Paragraphs (a) and (c) of This Section, Except for PFAS
BAT for Organic Contaminants Listed in § 141.61 (a) and (c)
CAS No.
| Contaminant
| GAC
| PTA
| OX
|
---|
15972-60-8 | Alachlor | X
| | |
116-06-3 | Aldicarb | X
| | |
1646-88-4 | Aldicarb sulfone | X
| | |
1646-87-3 | Aldicarb sulfoxide | X
| | |
1912-24-9 | Atrazine | X
| | |
71-43-2 | Benzene | X | X
| |
50-32-8 | Benzo[a]pyrene | X
| | |
1563-66-2 | Carbofuran | X
| | |
56-23-5 | Carbon tetrachloride | X | X
| |
57-74-9 | Chlordane | X
| | |
75-99-0 | Dalapon | X
| | |
94-75-7 | 2,4-D | X
| | |
103-23-1 | Di (2-ethylhexyl) adipate | X | X
| |
117-81-7 | Di (2-ethylhexyl) phthalate | X
| | |
96-12-8 | Dibromochloropropane (DBCP) | X | X
| |
95-50-1 | o-Dichlorobenzene | X | X
| |
106-46-7 | para-Dichlorobenzene | X | X
| |
107-06-2 | 1,2-Dichloroethane | X | X
| |
75-35-4 | 1,1-Dichloroethylene | X | X
| |
156-59-2 | cis-1,2-Dichloroethylene | X | X
| |
156-60-5 | trans-1,2-Dichloroethylene | X | X
| |
75-09-2 | Dichloromethane | | X
| |
78-87-5 | 1,2-Dichloropropane | X | X
| |
88-85-7 | Dinoseb | X
| | |
85-00-7 | Diquat | X
| | |
145-73-3 | Endothall | X
| | |
72-20-8 | Endrin | X
| | |
100-41-4 | Ethylbenzene | X | X
| |
106-93-4 | Ethylene Dibromide (EDB) | X | X
| |
1071-83-6 | Gylphosate | | | X
|
76-44-8 | Heptachlor | X
| | |
1024-57-3 | Heptachlor epoxide | X
| | |
118-74-1 | Hexachlorobenzene | X
| | |
77-47-3 | Hexachlorocyclopentadiene | X | X
| |
58-89-9 | Lindane | X
| | |
72-43-5 | Methoxychlor | X
| | |
108-90-7 | Monochlorobenzene | X | X
| |
23135-22-0 | Oxamyl (Vydate) | X
| | |
87-86-5 | Pentachlorophenol | X
| | |
1918-02-1 | Picloram | X
| | |
1336-36-3 | Polychlorinated biphenyls (PCB) | X
| | |
122-34-9 | Simazine | X
| | |
100-42-5 | Styrene | X | X
| |
1746-01-6 | 2,3,7,8-TCDD (Dioxin) | X
| | |
127-18-4 | Tetrachloroethylene | X | X
| |
108-88-3 | Toluene | X | X
| |
8001-35-2 | Toxaphene | X
| | |
93-72-1 | 2,4,5-TP (Silvex) | X
| | |
120-82-1 | 1,2,4-Trichlorobenzene | X | X
| |
71-55-6 | 1,1,1-Trichloroethane | X | X
| |
79-00-5 | 1,1,2-Trichloroethane | X | X
| |
79-01-6 | Trichloroethylene | X | X
| |
75-01-4 | Vinyl chloride | | X
| |
1330-20-7 | Xylene | X | X | |
(c) The following maximum contaminant levels (MCLs) in paragraphs (c)(1) and (2) of this section for synthetic organic contaminants apply to community water systems and non-transient, non-community water systems; paragraph (c)(2) of this section also contains health-based water concentrations (HBWCs) for selected per- and poly-fluoroalkyl substances (PFAS) used in calculating the Hazard Index.
(1) MCLs for Synthetic Organic Contaminants, Except for PFAS.
CAS No.
| Contaminant
| MCL
(mg/l)
|
---|
(i) 15972-60-8 | Alachlor | 0.002
|
(ii) 116-06-3 | Aldicarb | 0.003
|
(iii) 1646-87-3 | Aldicarb sulfoxide | 0.004
|
(iv) 1646-87-4 | Aldicarb sulfone | 0.002
|
(v) 1912-24-9 | Atrazine | 0.003
|
(vi) 1563-66-2 | Carbofuran | 0.04
|
(vii) 57-74-9 | Chlordane | 0.002
|
(viii) 96-12-8 | Dibromochloropropane | 0.0002
|
(ix) 94-75-7 | 2,4-D | 0.07
|
(x) 106-93-4 | Ethylene dibromide | 0.00005
|
(xi) 76-44-8 | Heptachlor | 0.0004
|
(xii) 1024-57-3 | Heptachlor epoxide | 0.0002
|
(xiii) 58-89-9 | Lindane | 0.0002
|
(xiv) 72-43-5 | Methoxychlor | 0.04
|
(xv) 1336-36-3 | Polychlorinated biphenyls | 0.0005
|
(xvi) 87-86-5 | Pentachlorophenol | 0.001
|
(xvii) 8001-35-2 | Toxaphene | 0.003
|
(xviii) 93-72-1 | 2,4,5-TP | 0.05
|
(xix) 50-32-8 | Benzo[a]pyrene | 0.0002
|
(xx) 75-99-0 | Dalapon | 0.2
|
(xxi) 103-23-1 | Di(2-ethylhexyl) adipate | 0.4
|
(xxii) 117-81-7 | Di(2-ethylhexyl) phthalate | 0.006
|
(xxiii) 88-85-7 | Dinoseb | 0.007
|
(xxiv) 85-00-7 | Diquat | 0.02
|
(xxv) 145-73-3 | Endothall | 0.1
|
(xxvi) 72-20-8 | Endrin | 0.002
|
(xvii) 1071-53-6 | Glyphosate | 0.7
|
(xxviii) 118-74-1 | Hexacholorbenzene | 0.001
|
(xxix) 77-47-4 | Hexachlorocyclopentadiene | 0.05
|
(xxx) 23135-22-0 | Oxamyl (Vydate) | 0.2
|
(xxxi) 1918-02-1 | Picloram | 0.5
|
(xxxii) 122-34-9 | Simazine | 0.004
|
(xxxiii) 1746-01-6 | 2,3,7,8-TCDD (Dioxin) | 3 × 10−
8 |
(2) MCLs and HBWCs for PFAS.
CAS. No.
| Contaminant
| MCL
(mg/l) (unless otherwise noted)
| HBWC
(mg/l) for Hazard Index calculation
|
---|
(i) Not applicable | Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA) | 1 (unitless)
1 | Not applicable.
|
(ii) 122499-17-6 | HFPO-DA | 0.00001 | 0.00001.
|
(iii) 45187-15-3 | PFBS | No individual MCL | 0.002.
|
(iv) 108427-53-8 | PFHxS | 0.00001 | 0.00001.
|
(v) 72007-68-2 | PFNA | 0.00001 | 0.00001.
|
(vi) 45285-51-6 | PFOA | 0.0000040 | Not applicable.
|
(vii) 45298-90-6 | PFOS | 0.0000040 | Not applicable.
|
Hazard Index = ([HFPO-DAwater ng/l]/[10 ng/l]) + ([PFBSwater ng/l]/[2000 ng/l]) + ([PFNAwater ng/l]/[10 ng/l]) + ([PFHxSwater ng/l]/[10 ng/l])
HBWC = health-based water concentration
HQ = hazard quotient
ng/l = nanograms per liter
PFASwater = the concentration of a specific PFAS in water
(d) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 3 to this paragraph (d) the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant levels for all regulated PFAS identified in paragraph (c) of this section:
Table 3 to Paragraph (d)—Best Available Technologies for PFAS Listed in Paragraph (c) of This Section
Contaminant
| BAT
|
---|
Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA) | Anion exchange, GAC, reverse osmosis, nanofiltration.
|
HFPO-DA | Anion exchange, GAC, reverse osmosis, nanofiltration.
|
PFHxS | Anion exchange, GAC, reverse osmosis, nanofiltration.
|
PFNA | Anion exchange, GAC, reverse osmosis, nanofiltration.
|
PFOA | Anion exchange, GAC, reverse osmosis, nanofiltration.
|
PFOS | Anion exchange, GAC, reverse osmosis, nanofiltration. |
(e) The Administrator, pursuant to section 1412 of the Act, hereby identifies in table 4 to this paragraph (e) the affordable technology, treatment technique, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the maximum contaminant levels for all regulated PFAS identified in paragraph (c) of this section:
Table 4 to Paragraph (e)—Small System Compliance Technologies (SSCTs) for PFAS
Small system
compliance
technology
1
| Affordable for listed small system
categories
2
|
---|
Granular Activated Carbon | All size categories.
|
Anion Exchange | All size categories.
|
Reverse Osmosis, Nanofiltration
3 | 3,301-10,000.
|
[56 FR 3593, Jan. 30, 1991, as amended at 56 FR 30280, July 1, 1991; 57 FR 31846, July 17, 1992; 59 FR 34324, July 1, 1994; 89 FR 32744, Apr. 26, 2024; 89 FR 49102, June 11, 2024]