40 CFR 146.22 - Construction requirements.
(a) All new Class II wells shall be sited in such a fashion that they inject into a formation which is separated from any USDW by a confining zone that is free of known open faults or fractures within the area of review.
(1) All Class II injection wells shall be cased and cemented to prevent 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:
(i) Depth to the injection zone;
(ii) Depth to the bottom of all USDWs; and
(iii) Estimated maximum and average injection pressures;
(2) In addition the Director may consider information on:
(i) Nature of formation fluids;
(ii) Lithology of injection and confining zones;
(iv) Hole size;
(v) Size and grade of all casing strings; and
(vi) Class of cement.
(e) Where a State did not have regulatory controls for casing and cementing prior to the time of the submission of the State program to the Administrator, the Director need not apply the casing and cementing requirements in paragraph (b) of this section if he submits as a part of his application for primacy, an appropriate plan for casing and cementing of existing, newly converted, and newly drilled wells in existing fields, and the Administrator approves the plan.
(f) Appropriate logs and other tests shall be conducted during the drilling and construction of new Class II wells. A descriptive report interpreting the results of that portion of those logs and tests which specifically relate to (1) an USDW and the confining zone adjacent to it, and (2) the injection and adjacent formations shall be prepared by a knowledgeable log analyst and submitted to the director. At a minimum, these 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 movement 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 shall be considered by the Director in setting logging and testing requirements:
(A) Electric and caliper logs before 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 injection:
(A) Electric 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.
(2) Estimated fracture pressure;
(3) Physical and chemical characteristics of the injection zone.