|(a) Based on the schedule established under §330.413(d) of this title (relating to Selection of Remedy) for initiation and completion of remedial activities, the owner or operator shall: (1) establish and implement a corrective action groundwater monitoring program that: (A) at least meets the requirements of an assessment monitoring program under §330.409 of this title (relating to Assessment Monitoring Program); (B) indicates the effectiveness of the corrective action remedy; and (C) demonstrates compliance with groundwater protection standards under subsection (f) of this section; (2) implement the corrective action remedy selected under §330.413 of this title; and (3) take any interim measures necessary to ensure the protection of human health and the environment. Interim measures should, to the greatest extent practicable, be consistent with the objectives of and contribute to the performance of any remedy that may be required under §330.413 of this title. The following factors shall be considered by an owner or operator in determining if interim measures are necessary: (A) time required to develop and implement a final remedy; (B) actual or potential exposure of nearby populations or environmental receptors to hazardous constituents; (C) actual or potential contamination of drinking water supplies or sensitive ecosystems; (D) further degradation of the groundwater that may occur if remedial action is not initiated expeditiously; (E) weather conditions that may cause hazardous constituents to migrate or be released; (F) risks of fire or explosion, or potential for exposure to hazardous constituents as a result of an accident or failure of a container or handling system; and (G) other situations that may pose threats to human health and the environment. (b) An owner or operator may determine, based on information developed after implementation of the remedy has begun or other information, that compliance with requirements of §330.413(b) of this title are not being achieved through the remedy selected. In such cases, the owner or operator shall, with approval of the executive director, implement other methods or techniques that could practicably achieve compliance with the requirements unless the owner or operator makes the determination under subsection (c) of this section and if it is approved by the executive director. Failure to obtain approval from the executive director for the other methods and techniques does not relieve the owner or operator of the burden to implement an acceptable remedy. (c) If the owner or operator determines that compliance with requirements under §330.413(b) of this title cannot be practically achieved with any currently available methods, the owner or operator shall: (1) present to the executive director certification by a qualified groundwater scientist that compliance with requirements under §330.413(b) of this title cannot be practically achieved with any currently available methods; (2) implement alternative measures, with the approval of the executive director, to control exposure of humans or the environment to residual contamination, as necessary to protect human health and the environment; (3) implement alternative measures, with the approval of the executive director, for control of the sources of contamination, or for removal or decontamination of equipment, units, devices, or structures that are technically practicable and consistent with the overall objective of the remedy; and (4) place a copy of all approved alternative measures in the operating record. (d) All solid wastes that are managed in accordance with a remedy required under §330.413 of this title, or an interim measure required under subsection (a)(3) of this section, shall be managed in a manner that is protective of human health and the environment and that complies with applicable Resource Conservation and Recovery Act requirements. (e) Upon implementation of a corrective action program, the owner or operator shall submit an annual corrective action report by March 1st every year that includes the following information determined since the previously submitted report: (1) a statement regarding whether a statistically significant level above a groundwater protection standard established in §330.409(h), (i), or (j) of this title in any well during the previous calendar year period has occurred and the status of any statistically significant level events; (2) the results of all groundwater monitoring, testing, and analytical work obtained or prepared in accordance with the requirements of this chapter, including a summary of background groundwater quality values, groundwater monitoring analyses, statistical calculations, graphs, and drawings; (3) the groundwater flow rate and direction in the uppermost aquifer. The groundwater flow rate and direction of groundwater flow shall be established using the data collected during the preceding calendar year's sampling events from the monitoring wells of the Corrective Action Program. The owner or operator shall also include in the report all documentation used to determine the groundwater flow rate and direction of groundwater flow; (4) a contour map of piezometric water levels in the uppermost aquifer based at a minimum upon concurrent measurement in all monitoring wells. All data or documentation used to establish the contour map should be included in the report; (5) recommendation for any changes; and (6) any other items requested by the executive director. (f) Remedies selected under §330.413 of this title shall be considered complete when: (1) the owner or operator complies with the groundwater protection standards established under §330.409(h), (i), or (j) of this title at all points within the plume of contamination that lies beyond the groundwater monitoring system established under §330.403 of this title (relating to Groundwater Monitoring Systems); (2) compliance with the groundwater protection standards established under §330.409 (h), (i), or (j) of this title has been achieved by demonstrating that concentrations of 40 Code of Federal Regulations Part 258, Appendix II constituents have not exceeded the groundwater protection standards for a period of three consecutive years, using the statistical procedures in §330.405(e) and (f) of this title (relating to Groundwater Sampling and Analysis Requirements) and performance standards in §330.409(h), (i), or (j) of this title. The executive director may specify an alternative length of time during which the owner or operator shall demonstrate that concentrations of 40 Code of Federal Regulations Part 258, Appendix II constituents have not exceeded the groundwater protection standards. The alternative length of time shall be based on: (A) extent and concentration of the release; (B) behavior characteristics of the hazardous constituents in the groundwater; (C) accuracy of monitoring or modeling techniques, including any seasonal, meteorological, or other environmental variabilities that may affect the accuracy; and (D) characteristics of the groundwater; and (3) all actions required to complete the remedy have been satisfied. (g) Within 15 days of completion of the remedy, the owner or operator shall submit to the executive director and also place in the operating record a certification by a qualified groundwater scientist that the remedy has been completed in compliance with the requirements of subsection (a) of this section. (h) Upon submittal of satisfactory certification of the completion of the corrective action remedy, the executive director may release the owner or operator from the requirements for financial assurance for corrective action under §330.509 of this title (relating to Corrective Action Cost Estimates for Landfills).