[Code of Federal Regulations]
[Title 40, Volume 27]
[Revised as ofJuly 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR440.42]

[Page 419]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 440--ORE MINING AND DRESSING POINT SOURCE CATEGORY--Table of Contents
 
                   Subpart D--Mercury Ore Subcategory
 
Sec. 440.42  Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology 
          currently available (BPT).

    Except as provided in subpart L of this part and 40 CFR 125.30 
through 125.32, any existing point source subject to this subpart must 
achieve the following effluent limitations representing the degree of 
effluent reduction attainable after application of the best practicable 
control technology currently available (BPT):
    (a) The concentration of pollutants discharged in mine drainage from 
mines, either open-pit or underground, operated for the production of 
mercury ores shall not exceed the following limitations:

------------------------------------------------------------------------
                                                 Effluent limitations
                                             ---------------------------
                                                             Average of
           Effluent characteristic                          daily values
                                               Maximum for     for 30
                                                any 1 day    consecutive
                                                                days
------------------------------------------------------------------------
                                                 Milligrams per liter
                                             ---------------
TSS.........................................        30            20
Hg..........................................          .002          .001
Ni..........................................          .2            .1
pH..........................................     (\1\)         (\1\)
------------------------------------------------------------------------
\1\ Within the range 6.0 to 9.0.

    (b)(1) Except as provided in paragraph (b) of this section, there 
shall be no discharge of process wastewater to navigable waters from 
mills beneficiating mercury ores by gravity separation methods or by 
froth flotation methods. The Agency recognizes that the elimination of 
the discharge of pollutants to navigable waters may result in an 
increase in discharges of some pollutants to other media. The Agency has 
considered these impacts and has addressed them in the preamble 
published on December 3, 1982.
    (2) In the event that the annual precipitation falling on the 
treatment facility and the drainage area contributing surface runoff to 
the treatment facility exceeds the annual evaporation, a volume of water 
equivalent to the difference between annual precipitation falling on the 
treatment facility and the drainage area contributing surface runoff to 
the treatment facility and annual evaporation may be discharged subject 
to the limitations set forth in paragraph (a)(1) of this section.