[Code of Federal Regulations]
[Title 40, Volume 20]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR146.12]

[Page 711-712]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 146_UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS--Table of Contents
 
      Subpart B_Criteria and Standards Applicable to Class I Wells
 
Sec.  146.12  Construction requirements.

    (a) All Class I wells shall be sited in such a fashion that they 
inject into a formation which is beneath the lowermost formation 
containing, within one quarter mile of the well bore, an underground 
source of drinking water.
    (b) All Class I wells shall be cased and cemented to prevent the 
movement of fluids into or between underground sources of drinking 
water. The casing and cement used in the construction of each newly 
drilled well shall be designed for the life expectancy of the well. In 
determining and specifying casing and cementing requirements, the 
following factors shall be considered:
    (1) Depth to the injection zone;
    (2) Injection pressure, external pressure, internal pressure, and 
axial loading;
    (3) Hole size;
    (4) Size and grade of all casing strings (wall thickness, diameter, 
nominal weight, length, joint specification, and construction material);
    (5) Corrosiveness of injected fluid, formation fluids, and 
temperatures;
    (6) Lithology of injection and confining intervals; and
    (7) Type or grade of cement.
    (c) All Class I injection wells, except those municipal wells 
injecting non-corrosive wastes, shall inject fluids through tubing with 
a packer set immediately above the injection zone, or tubing with an 
approved fluid seal as an alternative. The tubing, packer, and fluid 
seal shall be designed for the expected service.
    (1) The use of other alternatives to a packer may be allowed with 
the written approval of the Director. To obtain approval, the operator 
shall submit a written request to the Director, which shall set forth 
the proposed alternative and all technical data supporting its use. The 
Director shall approve the request if the alternative method will 
reliably provide a comparable level of protection to underground sources 
of drinking water. The Director may approve an alternative method solely 
for an individual well or for general use.
    (2) In determining and specifying requirements for tubing, packer, 
or alternatives the following factors shall be considered:
    (i) Depth of setting;
    (ii) Characteristics of injection fluid (chemical content, 
corrosiveness, and density);
    (iii) Injection pressure;
    (iv) Annular pressure;
    (v) Rate, temperature and volume of injected fluid; and
    (vi) Size of casing.
    (d) Appropriate logs and other tests shall be conducted during the 
drilling and construction of new Class I wells. A descriptive report 
interpreting the results of such logs and tests shall be prepared by a 
knowledgeable log analyst and submitted to the Director. At a minimum, 
such logs and tests shall include:
    (1) Deviation checks on all holes constructed by first drilling a 
pilot hole, and then enlarging the pilot hole by reaming or another 
method. Such checks shall be at sufficiently frequent intervals to 
assure that vertical avenues for fluid migration in the form of 
diverging holes are not created during drilling.
    (2) Such other logs and tests as may be needed after taking into 
account the availability of similar data in the area of the drilling 
site, the construction plan, and the need for additional information, 
that may arise from time to time as the construction of the well 
progresses. In determining which logs and tests shall be required, the 
following logs shall be considered for use in the following situations:
    (i) For surface casing intended to protect underground sources of 
drinking water:

[[Page 712]]

    (A) Resistivity, spontaneous potential, and caliper logs before the 
casing is installed; and
    (B) A cement bond, temperature, or density log after the casing is 
set and cemented.
    (ii) For intermediate and long strings of casing intended to 
facilitate [chyph]injection:
    (A) Resistivity, spontaneous potential, porosity, and gamma ray logs 
before the casing is installed;
    (B) Fracture finder logs; and
    (C) A cement bond, temperature, or density log after the casing is 
set and cemented.
    (e) At a minimum, the following information concerning the injection 
formation shall be determined or calculated for new Class I wells:
    (1) Fluid pressure;
    (2) Temperature;
    (3) Fracture pressure;
    (4) Other physical and chemical characteristics of the injection 
matrix; and
    (5) Physical and chemical characteristics of the formation fluids.

[45 FR 42500, June 24, 1980, as amended at 46 FR 43162, Aug. 27, 1981]