[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR143.3]

[Page 678-679]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 143_NATIONAL SECONDARY DRINKING WATER REGULATIONS--Table of Contents
 
Sec. 143.3  Secondary maximum contaminant levels.

    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.

[[Page 679]]


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]