[Code of Federal Regulations]
[Title 40, Volume 26]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR421.61]

[Page 482]
 
                TITLE 40-PROTECTION OF ENVIRONMENT
 
      CHAPTER I-ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 421-NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY--Table of Contents
 
              Subpart F-Secondary Copper Subcategory
 
Sec. 421.61  Specialized definitions.

    For the purpose of this subpart:
    (a) Except as provided below, the general definitions, 
abbreviations, and methods of analysis set forth in 40 CFR part 401 
shall apply to this subpart.
    (b) For all impoundments constructed prior to the effective date of 
this regulation the term ``within the 
impoundment'' when used for purposes of calculating the 
volume of process wastewater which may be discharged shall mean the 
water surface area within the impoundment at maximum capacity plus the 
surface area of the inside and outside slopes of the impoundment dam as 
well as the surface area between the outside edge of the impoundment dam 
and any seepage ditch immediately adjacent to the dam upon which rain 
falls and is returned to the impoundment. For the purpose of such 
calculations, the surface area allowances set forth above shall not be 
more than 30 percent of the water surface area within the impoundment 
dam at maximum capacity.
    (c) For all impoundments constructed on or after the effective date 
of this regulation, the term ``within the 
impoundment'' for purposes of calculating the volume of 
process wastewater which may be discharged shall mean the water surface 
area within the impoundment at maximum capacity.
    (d) The term pond water surface area when used for the purpose of 
calculating the volume of wastewater which may be discharged shall mean 
the water surface area of the pond created by the impoundment for 
storage of process wastewater at normal operating level. This surface 
shall in no case be less than one-third of the surface area of the 
maximum amount of water which could be contained by the impoundment. The 
normal operating level shall be the average level of the pond during the 
preceding calendar month.

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