[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR133.105]

[Page 492-493]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 133--SECONDARY TREATMENT REGULATION--Table of Contents
 
Sec. 133.105  Treatment equivalent to secondary treatment.

    This section describes the minimum level of effluent quality 
attainable by facilities eligible for treatment equivalent to secondary 
treatment (Sec. 133.101(g)) in terms of the parameters--BOD5, 
SS and pH. All requirements for the specified parameters in paragraphs 
(a), (b) and (c) of this section shall be achieved except as provided 
for in Sec. 133.103, or paragraphs (d), (e) or (f) of this section.
    (a) BOD5. (1) The 30-day average shall not exceed 45 mg/
l.
    (2) The 7-day average shall not exceed 65 mg/l.
    (3) The 30-day average percent removal shall not be less than 65 
percent.
    (b) SS. Except where SS values have been adjusted in accordance with 
Sec. 133.103(c):
    (1) The 30-day average shall not exceed 45 mg/l.
    (2) The 7-day average shall not exceed 65 mg/l.
    (3) The 30-day average percent removal shall not be less than 65 
percent.
    (c) pH. The requirements of Sec. 133.102(c) shall be met.
    (d) Alternative State requirements. Except as limited by paragraph 
(f) of this section, and after notice and opportunity for public 
comment, the Regional Administrator, or, if appropriate, State Director 
subject to EPA

[[Page 493]]

approval, is authorized to adjust the minimum levels of effluent quality 
set forth in paragraphs (a)(1), (a)(2), (b)(1) and (b)(2) of this 
section for trickling filter facilities and in paragraphs (a)(1) and 
(a)(2) of this section for waste stabilization pond facilities, to 
conform to the BOD5 and SS effluent concentrations 
consistently achievable through proper operation and maintenance 
(Sec. 133.101(f)) by the median (50th percentile) facility in a 
representative sample of facilities within a State or appropriate 
contiguous geographical area that meet the definition of facilities 
eligible for treatment equivalent to secondary treatment 
(Sec. 133.101(g)).

(The information collection requirements contained in this rule have 
been approved by OMB and assigned control number 2040-0051.)

    (e) CBOD5 limitations:
    (1) Where data are available to establish CBOD5 
limitations for a treatment works subject to this section, the NPDES 
permitting authority may substitute the parameter CBOD5 for 
the parameter BOD5 In Secs. 133.105(a)(1), 133.105(a)(2) and 
133.105(a)(3), on a case-by-case basis provided that the levels of 
CBOD5 effluent quality are not less stringent than the 
following:
    (i) The 30-day average shall not exceed 40 mg/l.
    (ii) The 7-days average shall not exceed 60 mg/l.
    (iii) The 30-day average percent removal shall not be less than 65 
percent.
    (2) Where data are available, the parameter CBOD5 may be 
used for effluent quality limitations established under paragraph (d) of 
this section. Where concurrent BOD effluent data are available, they 
must be submitted with the CBOD data as a part of the approval process 
outlined in paragraph (d) of this section.
    (f) Permit adjustments. Any permit adjustment made pursuant to this 
part may not be any less stringent than the limitations required 
pursuant to Sec. 133.105(a)-(e). Furthermore, permitting authorities 
shall require more stringent limitations when adjusting permits if: (1) 
For existing facilities the permitting authority determines that the 30-
day average and 7-day average BOD5 and SS effluent values 
that could be achievable through proper operation and maintenance of the 
treatment works, based on an analysis of the past performance of the 
treatment works, would enable the treatment works to achieve more 
stringent limitations, or
    (2) For new facilities, the permitting authority determines that the 
30-day average and 7-day average BOD5 and SS effluent values 
that could be achievable through proper operation and maintenance of the 
treatment works, considering the design capability of the treatment 
process and geographical and climatic conditions, would enable the 
treatment works to achieve more stringent limitations.

[49 FR 37006, Sept. 20, 1984; 49 FR 40405, Oct. 16, 1984]