[Code of Federal Regulations]
[Title 40, Volume 27]
[Revised as ofJuly 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR436.31]

[Page 351-352]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 436--MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY--Table of Contents
 
           Subpart C--Construction Sand and Gravel Subcategory
 
Sec. 436.31  Specialized definitions.

    For the purpose of this subpart:
    (a) Except as provided below, the general definitions, abbreviations 
and methods of analysis set forth in part 401 of this chapter shall 
apply to this subpart.
    (b) The term ``mine dewatering'' shall mean any water that is 
impounded or that collects in the mine and is pumped, drained or 
otherwise removed from the mine through the efforts of the mine 
operator. This term shall also include wet pit overflows caused solely 
by direct rainfall and ground water seepage. However, if a mine is also 
used for treatment of process generated waste water, discharges of 
commingled water from the mine shall be deemed discharges of process 
generated waste water.
    (c) The term ``10-year 24-hour precipitation event'' shall mean the 
maximum 24 hour precipitation event with a probable reoccurrence 
interval of once in 10 years. This information is available in ``Weather 
Bureau Technical Paper No. 40,'' May 1961 and ``NOAA Atlas 2,'' 1973 for 
the 11 Western States, and may be obtained from the National Climatic 
Center of the Environmental Data Service, National Oceanic and 
Atmospheric Administration, U.S. Department of Commerce.
    (d) The term ``mine'' shall mean an area of land, surface or 
underground, actively mined for the production of sand and gravel from 
natural deposits.
    (e) The term ``process generated waste water'' shall mean any waste 
water used in the slurry transport of mined material, air emissions 
control, or processing exclusive of mining. The

[[Page 352]]

term shall also include any other water which becomes commingled with 
such waste water in a pit, pond, lagoon, mine or other facility used for 
treatment of such waste water. The term does not include waste water 
used for the suction dredging of deposits in a body of water and 
returned directly to the body of waste without being used for other 
purposes or combined with other waste water.