| (2) When the executive director determines that an
injection well lacks mechanical integrity pursuant to paragraph (4)
of this subsection, the executive director shall give written notice
of his determination to the owner or operator. Unless the executive
director requires immediate cessation, the owner or operator shall
cease injection into the well within 48 hours of receipt of the executive
director's determination. The executive director may allow plugging
of the well in accordance with the requirements of §331.46 of
this title (relating to Closure Standards) or require the owner or
operator to perform such additional construction, operation, monitoring,
reporting and corrective action as is necessary to prevent the movement
of fluid into or between USDWs caused by the lack of mechanical integrity.
The owner or operator may resume injection upon receipt of written
notification from the executive director that the owner or operator
has demonstrated mechanical integrity under paragraph (4) of this
(3) The executive director may allow the owner or operator
of a well which lacks mechanical integrity under paragraph (4) of
this subsection to continue or resume injection if the owner or operator
has made a satisfactory demonstration that there is no movement of
fluid into or between USDWs.
(4) Mechanical Integrity Testing. An injection well
has mechanical integrity if:
(A) There is no significant leak in the casing, tubing
or packer; and
(B) There is no significant fluid movement into an
USDW through vertical channels adjacent to the injection well bore.
(5) One of the following methods shall be used to evaluate
the absence of significant leaks under paragraph (4)(A) of this subsection:
(A) Following an initial pressure test, monitoring
of the tubing-casing annulus pressure with sufficient frequency to
be representative, as determined by the executive director, while
maintaining an annulus pressure different from atmospheric pressure
measured at the surface; or
(B) Pressure test with liquid or gas.
(6) The results of a temperature or noise log must
be used to determine the absence of significant fluid movement under
paragraph (4)(B) of this subsection.
(7) The executive director may allow the use of a test
to demonstrate mechanical integrity other than those listed in paragraph
(5)(A) and (B) of this subsection with the written approval of the
executive director. To obtain approval, the permittee shall submit
a written request to the executive director, which shall set forth
the proposed test and all technical data supporting its use. The executive
director shall approve the request if it will reliably demonstrate
the mechanical integrity of wells for which its use is proposed.
(8) In conducting and evaluating the tests enumerated
in this section or others to be allowed by the executive director,
the owner or operator and the executive director shall apply methods
and standards generally accepted in the industry. When the owner or
operator reports the results of mechanical integrity tests to the
executive director, he shall include a description of the test(s)
and the method(s) used. In making his evaluation, the executive director
shall review monitoring and other test data submitted since the previous
(9) The executive director may require additional or
alternative tests if the results presented by the owner or operator
under §331.64(k)(5) of this title (relating to Monitoring and
Testing Requirements) are not satisfactory to the executive director
to demonstrate that there is no movement of fluid into or between
USDWs resulting from the injection activity.
(10) Ambient monitoring.
(A) Based on a site-specific assessment of the potential
for fluid movement from the well or injection zone and on the potential
value of monitoring wells to detect such movement, the executive director
shall require the owner or operator to develop a monitoring program.
At a minimum, the executive director shall require monitoring of the
pressure buildup in the injection zone annually, including a shut
down of the well for a time sufficient to conduct a valid observation
of the pressure fall-off curve.
(B) When prescribing a monitoring system the executive
director may also require:
(i) Continuous monitoring for pressure changes in the
first aquifer overlying the confining zone. When such a well is installed,
the owner or operator shall, on a quarterly basis, sample the aquifer
and analyze for constituents specified by the executive director;
(ii) The use of indirect, geophysical techniques to
determine the position of the waste front, the water quality in a
formation designated by the executive director, or to provide other
(iii) Periodic monitoring of the ground water quality
in the first aquifer overlying the injection zone;
(iv) Periodic monitoring of the ground water quality
in the lowermost USDW; and
(v) Any additional monitoring necessary to determine
whether fluids are moving into or between USDWs.
|Source Note: The provisions of this §331.64 adopted to be effective May 13, 1986, 11 TexReg 1983; amended to be effective July 5, 1989, 14 TexReg 3047; amended to be effective January 2, 1995, 19 TexReg 10099; amended to be effective April 28, 1997, 22 TexReg 3526; amended to be effective July 10, 2008, 33 TexReg 5342; amended to be effective January 7, 2021, 46 TexReg 191