This subpart establishes National Secondary Drinking Water Regulations pursuant to section 1412 of the Safe Drinking Water Act, as amended (42 U.S.C. 300g-1). The regulations in this subpart control contaminants in drinking water that primarily affect the aesthetic qualities relating to the public acceptance of drinking water. At considerably higher concentrations of these contaminants, health implications may also exist as well as aesthetic degradation. The regulations in this subpart are not Federally enforceable but are intended as guidelines for the States.
[44 FR 42198, July 19, 1979, as amended at 85 FR 54256, Sept. 1, 2020]
(a) Act means the Safe Drinking Water Act as amended (42 U.S.C. 300f et seq.).
(b) Contaminant means any physical, chemical, biological, or radiological substance or matter in water.
(c) Public water system means a system for the provision to the public of piped water for human consumption, if such a system has at least fifteen service connections or regularly serves an average of at least twenty-five individuals daily at least 60 days out of the year. Such term includes (1) any collection, treatment, storage, and distribution facilities under control of the operator of such system and used primarily in connection with such system, and (2) any collection or pretreatment storage facilities not under such control which are used primarily in connection with such system. A public water system is either a “community water system” or a “non-community water system.”
(d) State means the agency of the State or Tribal government which has jurisdiction over public water systems. During any period when a State does not have responsibility pursuant to section 1443 of the Act, the term “State” means the Regional Administrator, U.S. Environmental Protection Agency.
(e) Supplier of water means any person who owns or operates a public water system.
(f) Secondary maximum contaminant levels means SMCLs which apply to public water systems and which, in the judgement of the Administrator, are requisite to protect the public welfare. The SMCL means the maximum permissible level of a contaminant in water which is delivered to the free flowing outlet of the ultimate user of public water system. Contamimants added to the water under circumstances controlled by the user, except those resulting from corrosion of piping and plumbing caused by water quality, are excluded from this definition.
[44 FR 42198, July 19, 1979, as amended at 53 FR 37412, Sept. 26, 1988]
The secondary maximum contaminant levels for public water systems are as follows:
Contaminant
| Level
|
---|
Aluminum | 0.05 to 0.2 mg/l.
|
Chloride | 250 mg/l.
|
Color | 15 color units.
|
Copper | 1.0 mg/l.
|
Corrosivity | Non-corrosive.
|
Fluoride | 2.0 mg/l.
|
Foaming agents | 0.5 mg/l.
|
Iron | 0.3 mg/l.
|
Manganese | 0.05 mg/l.
|
Odor | 3 threshold odor number.
|
pH | 6.5-8.5.
|
Silver | 0.1 mg/l.
|
Sulfate | 250 mg/l.
|
Total dissolved solids (TDS) | 500 mg/l.
|
Zinc | 5 mg/l. |
These levels represent reasonable goals for drinking water quality. The States may establish higher or lower levels which may be appropriate dependent upon local conditions such as unavailability of alternate source waters or other compelling factors, provided that public health and welfare are not adversely affected.
[44 FR 42198, July 19, 1979, as amended at 51 FR 11412, Apr. 2, 1986; 56 FR 3597, Jan. 30, 1991]
(a) It is recommended that the parameters in these regulations should be monitored at intervals no less frequent than the monitoring performed for inorganic chemical contaminants listed in the National Interim Primary Drinking Water Regulations as applicable to community water systems. More frequent monitoring would be appropriate for specific parameters such as pH, color, odor or others under certain circumstances as directed by the State.
(b) Measurement of pH, copper and fluoride to determine compliance under § 143.3 may be conducted with one of the methods in § 141.23(k)(1). Analyses of aluminum, chloride, foaming agents, iron, manganese, odor, silver, sulfate, total dissolved solids (TDS) and zinc to determine compliance under § 143.3 may be conducted with the methods in the following table or alternative methods listed in appendix A to subpart C of part 141. Criteria for analyzing aluminum, copper, iron, manganese, silver and zinc samples with digestion or directly without digestion, and other analytical test procedures are contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 1994. This document is available from the National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242-0419 or http://www.epa.gov/nscep/.
Contaminant
| EPA
| ASTM
3
| SM
4 18th and 19th ed.
| SM
4 20th ed.
| SM
7 Online
| Other
|
---|
1. Aluminum | 200.7
2 | | 3120 B | 3120 B | 3120 B-99
| |
| 200.8
2 | | 3113 B | | 3113 B-99
| |
| 200.9
2 | | 3111 D | | 3111 D-99
| |
2. Chloride | 300.0
1, 300.1
6 | D4327-97, 03 | 4110 B | 4110 B | 4110 B-00
| |
| | | 4500-Cl− D | 4500-Cl− D | 4500-Cl− D-97
| |
| | D512-89 (Reapproved 1999) B | 4500-Cl− B | 4500-Cl− B | 4500-Cl− B-97
| |
| | | | | | D6508, Rev. 2
8
|
3. Color | | | 2120 B | 2120 B | 2120 B-01
| |
4. Foaming Agents | | | 5540 C | 5540 C | 5540 C-00
| |
5. Iron | 200.7
2 | | 3120 B | 3120 B | 3120 B-99
| |
| 200.9
2 | | 3111 B | | 3111 B-99
| |
| | | 3113 B | | 3113 B-99
| |
6. Manganese | 200.7
2 | | 3120 B | 3120 B | 3120 B-99
| |
| 200.8
2 | | 3111 B | | 3111 B-99
| |
| 200.9
2 | | 3113 B | | 3113 B-99
| |
7. Odor | | | 2150 B | 2150 B | 2150 B-97
| |
8. Silver | 200.7
2 | | 3120 B | 3120 B | 3120 B-99. | I-3720-85
5
|
| 200.8
2 | | 3111 B | | 3111 B-99
| |
| 200.9
2 | | 3113 B | | 3113 B-99
| |
9. Sulfate | 300.0
1, 300.1
6 | D4327-97, 03 | 4110 B | 4110 B | 4110 B-00
| |
| 375.2
1 | | 4500-SO4
2− F | 4500-SO4
2− F
| | |
| | | 4500-SO4
2− C, D | 4500-SO4
2− C, D
| | |
| | D516-90, 02 | 4500-SO4
2− E | 4500-SO4
2− E
| | |
| | | | | | D6508, Rev. 2
8
|
10. Total Dissolved Solids | | | 2540 C | 2540 C | 2540 C-97
| |
11. Zinc | 200.7
2 | | 3120 B | 3120 B | 3120 B-99
| |
| 200.8
2 | | 3111 B | | 3111 B-99
| |
[44 FR 42198, July 19, 1979, as amended at 53 FR 5147, Feb. 19, 1988; 56 FR 30281, July 1, 1991; 59 FR 62470, Dec. 5, 1994; 64 FR 67466, Dec. 1, 1999; 67 FR 65252, Oct. 23, 2002; 69 FR 18803, Apr. 9, 2004; 72 FR 11248, Mar. 12, 2007; 74 FR 30959, June 29, 2009]