[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: 40CFR421.11]

[Page 461-462]
 
                TITLE 40-PROTECTION OF ENVIRONMENT
 
      CHAPTER I-ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 421-NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY--Table of Contents
 
              Subpart A-Bauxite Refining Subcategory
 
Sec. 421.11  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.

[[Page 462]]

    (b) The term bauxite shall mean ore containing alumina monohydrate 
or alumina trihydrate which serves as the principal raw material for the 
production of alumina by the Bayer process or by the combination 
process.
    (c) The term product shall mean alumina.
    (d) For all impoundments the term within the impoundment for 
purposes of calculating the volume of process wastewater which may be 
discharged, shall mean the surface area within the impoundment at the 
maximum capacity plus the area of the inside and outside slopes of the 
impoundment dam and the surface area between the outside edge of the 
impoundment dam and seepage ditches upon which rain falls and is 
returned to the impoundment. For the purpose of such calculations, the 
surface area allowance for external appurtenances to the impoundment 
shall not be more than 30 percent of the water surface area within the 
impoundment dam at maximum capacity.
    (e) The term pond water surface area for the purpose of calculating 
the volume of waste water shall mean the area within the impoundment for 
rainfall and the actual water surface area for evaporation.

[39 FR 12825, Apr. 8, 1974, as amended at 40 FR 48348, Oct. 15, 1975]