[Code of Federal Regulations]
[Title 40, Volume 19]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR141.13]

[Page 344-345]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS--Table of Contents
 
                  Subpart B--Maximum Contaminant Levels
 
Sec. 141.13  Maximum contaminant levels for turbidity.

    The maximum contaminant levels for turbidity are applicable to both 
community water systems and non-community water systems using surface 
water sources in whole or in part. The maximum contaminant levels for 
turbidity in drinking water, measured at a representative entry point(s) 
to the distribution system, are:

    Editorial Note: At 54 FR 27527, June 29, 1989, Sec. 141.13 was 
amended by adding introductory text, effective December 31, 1990, 
however, introductory text already exists. The recently added text 
follows.
    The requirements in this section apply to unfiltered systems until 
December 30, 1991, unless the State has determined prior to that date, 
in writing pursuant to Sec. 1412(b)(7)(C)(iii), that filtration is 
required. The requirements

[[Page 345]]

in this section apply to filtered systems until June 29, 1993. The 
requirements in this section apply to unfiltered systems that the State 
has determined, in writing pursuant to Sec. 1412(b)(7)(C)(iii), must 
install filtration, until June 29, 1993, or until filtration is 
installed, whichever is later.
    (a) One turbidity unit (TU), as determined by a monthly average 
pursuant to Sec. 141.22, except that five or fewer turbidity units may 
be allowed if the supplier of water can demonstrate to the State that 
the higher turbidity does not do any of the following:
    (1) Interfere with disinfection;
    (2) Prevent maintenance of an effective disinfectant agent 
throughout the distribution system; or
    (3) Interfere with microbiological determinations.
    (b) Five turbidity units based on an average for two consecutive 
days pursuant to Sec. 141.22.

[40 FR 59570, Dec. 24, 1975]