[Code of Federal Regulations]
[Title 40, Volume 29]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR434.64]

[Page 285]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 434_COAL MINING POINT SOURCE CATEGORY BPT, BAT, BCT LIMITATIONS
AND NEW SOURCE PERFORMANCE STANDARDS--Table of Contents
 
                   Subpart F_Miscellaneous Provisions
 
Sec. 434.64  Procedure and method detection limit for measurement of settleable solids.

    For the purposes of this part, the following procedure shall be used 
to determine settleable solids: Fill an Imhoff cone to the one-liter 
mark with a thoroughly mixed sample. Allow to settle undisturbed for 45 
minutes. Gently stir along the inside surface of the cone with a 
stirring rod. Allow to settle undisturbed for 15 minutes longer. Record 
the volume of settled material in the cone as milliliters per liter. 
Where a separation of settleable and floating materials occurs, do not 
include the floating material in the reading. Notwithstanding any 
provision of 40 CFR part 136, the method detection limit for measuring 
settleable solids under this part shall be 0.4 ml/l.