[Code of Federal Regulations]
[Title 40, Volume 24]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR264.222]

[Page 327]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 264_STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, 
STORAGE, AND DISPOSAL FACILITIES--Table of Contents
 
                     Subpart K_Surface Impoundments
 
Sec. 264.222  Action leakage rate.

    (a) The Regional Administrator shall approve an action leakage rate 
for surface impoundment units subject to Sec. 264.221 (c) or (d). The 
action leakage rate is the maximum design flow rate that the leak 
detection system (LDS) can remove without the fluid head on the bottom 
liner exceeding 1 foot. The action leakage rate must include an adequate 
safety margin to allow for uncertainties in the design (e.g., slope, 
hydraulic conductivity, thickness of drainage material), construction, 
operation, and location of the LDS, waste and leachate characteristics, 
likelihood and amounts of other sources of liquids in the LDS, and 
proposed response actions (e.g., the action leakage rate must consider 
decreases in the flow capacity of the system over time resulting from 
siltation and clogging, rib layover and creep of synthetic components of 
the system, overburden pressures, etc.).
    (b) To determine if the action leakage rate has been exceeded, the 
owner or operator must convert the weekly or monthly flow rate from the 
monitoring data obtained under Sec. 264.226(d) to an average daily flow 
rate (gallons per acre per day) for each sump. Unless the Regional 
Administrator approves a different calculation, the average daily flow 
rate for each sump must be calculated weekly during the active life and 
closure period, and if the unit is closed in accordance with Sec. 
264.228(b), monthly during the post-closure care period when monthly 
monitoring is required under Sec. 264.226(d).

[57 FR 3487, Jan. 29, 1992]