OAR 340-040-0040: Remedial Investigation and Feasibility Study

(1) If, based upon the preliminary assessment or other information, the Director determines there is a substantial likelihood that remedial action will be necessary to maintain or restore groundwater quality to achieve a specified concentration limit, or to protect public health, safety, or welfare or the environment, the Director shall require a remedial investigation and/or feasibility study be performed to develop information to determine the need for and selection of a remedial action. (2) The Department shall develop and maintain a list of all facilities currently developing remedial investigations and feasibility studies, and shall make such a list available to the public on request. (3) The remedial investigation shall include but is not limited to characterization of pollution, characterization of the facility, and an endangerment assessment. In presenting the required information, a clear description of the data used as well as any data gaps encountered in the analysis shall be included: (a) The characterization of the pollution as appropriate shall include but is not limited to information regarding: (A) Extent to which the source can be adequately identified and characterized; (B) Amount, form, concentration, toxicity, environmental fate and transport, and other significant characterization of present substances; and (C) Extent to which the substances might be reused or recycled. (b) The characterization of the facility as appropriate shall include but is not limited to information regarding: (A) Contaminant substance mixtures present, media of occurrence, and interface zones between media; (B) Hydrogeologic factors; (C) Climatologic and meteorologic factors; and (D) Type, location, and description of facilities, or activities that could have resulted in the pollution. (c) The endangerment assessment as appropriate shall include but is not limited to information regarding: (A) Potential routes of exposure and concentration; (B) Characterization of toxic effects; (C) Populations at risk; (D) Potential or actual adverse impact on: (i) Biological receptors; (ii) Present and future uses of the groundwater; (iii) Ecosystems and natural resources; and (iv) Aesthetic characteristics of the environment. (E) Extent to which substances have migrated or are expected to migrate and the threat such migration might pose to public health, safety and welfare or the environment; and (F) Potential for release of any substances or treatment residuals that might remain after remedial action. (4) The feasibility study shall include but is not limited to the development and evaluation of remedial action options: (a) The development of remedial action options as appropriate shall include but is not limited to the following range of options: (A) Remedial action attaining the specified concentration limit; (B) Highest and best technology attaining the lowest concentration levels technically achievable if paragraph (4)(a)(A) of this rule is not technically achievable; (C) Best practicable technology attaining the lowest concentration level that meets the requirements of OAR 340-040-0050(1)(b) and (2), and does not exceed a site-specific concentration level considered protective of public health, safety, and welfare and the environment; (D) Other measures to supplement or substitute for cleanup technologies, including but not limited to engineering or institutional controls (e.g., environmental hazard notice, alternative drinking water supply, caps, security measures, etc.); (E) Combinations of any of the above options; and (F) No action option. (b)(A) Remedial action options developed under subsection (4)(a) of this rule shall be evaluated under the requirements, criteria, preferences, and factors set forth in OAR 340-040-0050 and according to any other criteria determined by the Director to be relevant to selection of a remedial action under OAR 340-040-0050; (B) The evaluation of remedial action options developed under subsection (4)(a) of this rule shall include an evaluation of the extent to which the option or combination of options complies with relevant state, local, and federal law, standards, and guidance.