(a) At any point after reviewing the information submitted in compliance with §§334.76-334.78 of this title (relating to Initial Response to Releases; Initial Abatement Measures and Site Check; and Site Assessment), the agency may require owners or operators to submit additional information or to develop and submit a corrective action plan for responding to contaminated soils and groundwater. If a plan is required, owners and operators must submit the plan according to a schedule and format established by the agency. Alternatively, owners and operators may, after fulfilling the requirements of §§334.76-334.78 of this title, choose to submit a corrective action plan for responding to contaminated soil and groundwater. In either case, owners and operators are responsible for submitting a plan that provides for adequate protection of human health, safety, and the environment as determined by the agency, and must modify their plan as necessary to meet this standard.
(b) The agency will approve the corrective action plan after ensuring that implementation of the plan will adequately protect human health, safety, and the environment as determined in §334.203 of this title (relating to Risk Based Criteria for Establishing Target Concentrations) and to achieve case closure criteria. In making this determination, the agency will consider the following factors as deemed appropriate:
  (1) the physical and chemical characteristics of the regulated substance, including its toxicity, persistence, and potential for migration;
  (2) the hydrogeologic characteristics of the facility and the surrounding area;
  (3) the proximity, quality, and current and future uses of nearby surface water and groundwater;
  (4) the potential effects of residual contamination on nearby surface water and groundwater;
  (5) an exposure assessment;
  (6) a determination of the most effective and feasible method of remediation;
  (7) an estimate of the time to achieve cleanup;
  (8) operation, monitoring, and performance plan; and
  (9) any information assembled in compliance with this subchapter.
(c) Owners and operators shall submit information pertaining to the items in subsection (b) of this section upon request of the agency.
(d) Any documents submitted as a corrective action plan which do not contain all of the information required by this section shall not be accepted or approved by the agency, may be returned by the agency, and shall not qualify as a submitted corrective action plan for the purposes of this chapter. Return of such documents by the agency does not prevent the owner or operator from filing subsequent corrective action plan documentation.
(e) Upon approval of the corrective action plan or as directed by the agency, owners and operators must implement the plan, including any revisions to the plan as requested by the agency. They must monitor, evaluate, and report the results of implementing the plan in accordance with a schedule and in a format established by the agency.
(f) Owners and operators may, in the interest of minimizing environmental contamination and promoting more effective cleanup, begin cleanup of soil and groundwater before the corrective action is approved provided that they:
  (1) notify the agency of their intention to begin cleanup;
  (2) comply with any conditions imposed by the agency, including halting cleanup or mitigating adverse consequences from cleanup activities;
  (3) incorporate these self-initiated cleanup measures in the corrective action plan that is submitted to the agency for approval; and
  (4) prior to discharge of any waste, obtain necessary authorization from the agency.
(g) To verify the effectiveness of corrective action taken by the owner or operator, the agency may require continued monitoring of soil, vapors, groundwater, and/or surface water.
(h) Upon completion of corrective action taken in response to the requirements of this section, the owner or operator must submit a statement signed by the owner or operator which certifies that the requirements of this section and the procedures in the approved corrective action plan have been accomplished.
(i) The agency will issue a closure letter in response to the certification of completion of corrective action requirements submitted by the owner or operator as required in subsection (h) of this section.

Source Note: The provisions of this §334.81 adopted to be effective September 29, 1989, 14 TexReg 4714; amended to be effective November 8, 1995, 20 TexReg 8800; amended to be effective November 23, 2000, 25 TexReg 11442