[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR146.71]

[Page 747-748]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 146_UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS
--Table of Contents
 
 Subpart G_Criteria and Standards Applicable to Class I Hazardous Waste 
                             Injection Wells
 
Sec.  146.71  Closure.

    (a) Closure Plan. The owner or operator of a Class I hazardous waste 
injection well shall prepare, maintain, and comply with a plan for 
closure of the well that meets the requirements of paragraph (d) of this 
section and is acceptable to the Director. The obligation to implement 
the closure plan survives the termination of a permit or the cessation 
of injection activities. The requirement to maintain and implement an 
approved plan is directly enforceable regardless of whether the 
requirement is a condition of the permit.
    (1) The owner or operator shall submit the plan as a part of the 
permit application and, upon approval by the Director, such plan shall 
be a condition of any permit issued.
    (2) The owner or operator shall submit any proposed significant 
revision to the method of closure reflected in the plan for approval by 
the Director no later than the date on which notice of closure is 
required to be submitted to the Director under paragraph (b) of this 
section.
    (3) The plan shall assure financial responsibility as required in 
Sec.  144.52(a)(7).
    (4) The plan shall include the following information:
    (i) The type and number of plugs to be used;
    (ii) The placement of each plug including the elevation of the top 
and bottom of each plug;
    (iii) The type and grade and quantity of material to be used in 
plugging;
    (iv) The method of placement of the plugs;
    (v) Any proposed test or measure to be made;

[[Page 748]]

    (vi) The amount, size, and location (by depth) of casing and any 
other materials to be left in the well;
    (vii) The method and location where casing is to be parted, if 
applicable;
    (viii) The procedure to be used to meet the requirements of 
paragraph (d)(5) of this section;
    (ix) The estimated cost of closure; and
    (x) Any proposed test or measure to be made.
    (5) The Director may modify a closure plan following the procedures 
of Sec.  124.5.
    (6) An owner or operator of a Class I hazardous waste injection well 
who ceases injection temporarily, may keep the well open provided he:
    (i) Has received authorization from the Director; and
    (ii) Has described actions or procedures, satisfactory to the 
Director, that the owner or operator will take to ensure that the well 
will not endanger USDWs during the period of temporary disuse. These 
actions and procedures shall include compliance with the technical 
requirements applicable to active injection wells unless waived by the 
Director.
    (7) The owner or operator of a well that has ceased operations for 
more than two years shall notify the Director 30 days prior to resuming 
operation of the well.
    (b) Notice of intent to close. The owner or operator shall notify 
the Director at least 60 days before closure of a well. At the 
discretion of the Director, a shorter notice period may be allowed.
    (c) Closure report. Within 60 days after closure or at the time of 
the next quarterly report (whichever is less) the owner or operator 
shall submit a closure report to the Director. If the quarterly report 
is due less than 15 days after completion of closure, then the report 
shall be submitted within 60 days after closure. The report shall be 
certified as accurate by the owner or operator and by the person who 
performed the closure operation (if other than the owner or operator). 
Such report shall consist of either:
    (1) A statement that the well was closed in accordance with the 
closure plan previously submitted and approved by the Director; or
    (2) Where actual closure differed from the plan previously 
submitted, a written statement specifying the differences between the 
previous plan and the actual closure.
    (d) Standards for well closure. (1) Prior to closing the well, the 
owner or operator shall observe and record the pressure decay for a time 
specified by the Director. The Director shall analyze the pressure decay 
and the transient pressure observations conducted pursuant to Sec.  
146.68(e)(1)(i) and determine whether the injection activity has 
conformed with predicted values.
    (2) Prior to well closure, appropriate mechanical integrity testing 
shall be conducted to ensure the integrity of that portion of the long 
string casing and cement that will be left in the ground after closure. 
Testing methods may include:
    (i) Pressure tests with liquid or gas;
    (ii) Radioactive tracer surveys;
    (iii) Noise, temperature, pipe evaluation, or cement bond logs; and
    (iv) Any other test required by the Director.
    (3) Prior to well closure, the well shall be flushed with a buffer 
fluid.
    (4) Upon closure, a Class I hazardous waste well shall be plugged 
with cement in a manner that will not allow the movement of fluids into 
or between USDWs.
    (5) Placement of the cement plugs shall be accomplished by one of 
the following:
    (i) The Balance Method;
    (ii) The Dump Bailer Method;
    (iii) The Two-Plug Method; or
    (iv) An alternate method, approved by the Director, that will 
reliably provide a comparable level of protection.
    (6) Each plug used shall be appropriately tagged and tested for seal 
and stability before closure is completed.
    (7) The well to be closed shall be in a state of static equilibrium 
with the mud weight equalized top to bottom, either by circulating the 
mud in the well at least once or by a comparable method prescribed by 
the Director, prior to the placement of the cement plug(s).