| (a) To attain Remedy Standard B, the person shall: (1) Remove, decontaminate, and/or control the surface soil, subsurface soil, and groundwater human health PCLE zones, other environmental media, and hazardous and non-hazardous waste in accordance with the provisions of this section such that humans will not be exposed to concentrations of COCs in the exposure media in excess of the residential or commercial/industrial critical human health PCLs, as applicable, at the prescribed, or any approved alternate POEs established for environmental media in accordance with §350.37 of this title (relating to Human Health Points of Exposure); (2) Ensure that leachate from the surface and subsurface soil PCLE zones does not increase the concentration of COCs in class 2 groundwater above the measured concentration at the time of RAP submittal in circumstances when an alternate POE to class 2 groundwater is authorized in response to subsection (f)(4) of this section; and (3) Use either subparagraph (A) or (B) of this paragraph to respond to an affected property when either the initial concentrations of COCs within environmental media exceed only the ecological PCLs (i.e., there is no exceedence of human health PCLs) or when there will be residual concentrations of COCs above the ecological PCLs following completion of a human health response action. When human health PCLs are exceeded within environmental media at an affected property, a person must perform a response action pursuant to paragraph (1) of this subsection to address these risks to human health unless the person adequately demonstrates that the threats to human health are minimal and that a human health-based response action would have a significant and highly disproportionate effect on ecological receptors. (A) The person shall remove, decontaminate, and/or control the environmental media, and hazardous and non-hazardous waste in accordance with the provisions of this section such that ecological receptors will not be exposed to concentrations of COCs in the exposure medium in excess of the ecological PCLs at the POEs determined in accordance with §350.77 of this title (relating to Ecological Risk Assessment and Development of Ecological Protective Concentration Levels). (B) When, after consultation with the Natural Resource Trustees, it is determined appropriate by the executive director, the person may use the results of a Tier 2 or 3 ecological risk assessment performed in accordance with §350.77 of this title (relating to Ecological Risk Assessment and Development of Ecological Protective Concentration Levels) and other appropriate information or data to conduct an ecological services analysis of the affected property. However, an ecological services analysis must be conducted whenever concentrations of COCs which exceed ecological PCLs are proposed to be left in place with the potential for continuing exposure. The ecological services analysis must, at a minimum, include an evaluation of the effects of reasonable and feasible remediation alternatives, including complete removal/decontamination to PCLs and a control measure to prevent ecological exposure to COCs in excess of ecological PCLs, with respect to present and predicted losses of ecological services; and clear justification for leaving COCs in place above ecological PCLs. Furthermore, the person shall also ensure, where appropriate, that the ecological services analysis includes a plan to provide compensatory ecological restoration which may also be combined with some type of active response action (e.g., hot spot removal) or passive response action (e.g., natural attenuation) for the affected property. The ecological services produced by the restoration activity must exceed the future ecological service decreases potentially associated with the continued exposure to COCs and/or any selected response action at the affected property. The person must conduct the compensatory ecological restoration and other activities associated with the ecological services analysis with the approval of and in cooperation with the Natural Resource Trustees. The executive director may develop guidance which further describes the ecological services analysis process. (b) As defined further by the surface and subsurface soil response objectives in subsection (e) of this section and the groundwater response objectives in subsection (f) of this section, the person performing a response action to attain Remedy Standard B may use removal and/or decontamination, removal and/or decontamination with controls, or controls only, with the exception of response actions for Class 1 groundwater PCLE zones which must be removed and/or decontaminated to the critical groundwater PCL for each COC. (1) The person may use both physical and institutional controls. (2) For all actions to attain Remedy Standard B, the person shall demonstrate that the response actions which they propose to use will attain the requirements of subsection (a) of this section within a reasonable time frame given the particular circumstances of an affected property. Remedial alternatives, including the use of monitored natural attenuation as a decontamination or control remedy, must be appropriate considering the hydrogeologic characteristics of the affected property, COC characteristics, and the potential for unprotective exposure conditions to continue or result during the remedial period. (c) PCLs for Remedy Standard B are determined through consideration of on-site and off-site POEs, or alternate POEs. (d) Remedy Standard B is not a self-implementing standard. The person must receive the executive director's written approval of a RAP and an APAR, either submitted at the same time as the RAP or previously, before commencing response actions to attain the standard, but this does not preclude the person from taking interim measures. (e) The following are the Remedy Standard B surface and subsurface soil response objectives and associated requirements for response actions performed in accordance with subsections (a)(1) - (2), and (a)(3)(A) of this section to address human health and/or ecological risks at an affected property. A person may choose to attain the surface and subsurface soil response objectives for an affected property either by conducting a response action which makes use of removal and/or decontamination or by conducting a response action which makes use of removal and/or decontamination with controls or controls only. (1) When all surface and subsurface soil response objectives specified in subsection (a) of this section are met through removal and/or decontamination, then the person shall fulfill any post-response action care obligations described in the approved RAP, but shall not be required to provide financial assurance for the soils. (2) When a person chooses to attain the surface and subsurface soil response objectives specified in subsection (a) of this section for an affected property by conducting a response action which uses removal and/or decontamination with controls or controls only, then the person must also comply with the requirements of this paragraph. (A) The person shall demonstrate that any physical control or combination of measures proposed to be used (e.g., waste control unit, cap, slurry wall, treatment that does not attain decontamination; or a landfill) will reliably contain COCs within and/or derived from the surface and subsurface soil PCLE zone materials over time. (B) The person shall fulfill the post-response action care obligations described in the approved RAP. (C) The person shall provide financial assurance in accordance with subsections (l) and (m) of this section. (f) The following are the Remedy Standard B groundwater response objectives and associated requirements for response actions performed in accordance with subsections (a)(1) - (2), and (a)(3)(A) of this section to address human health or environmental risk at an affected property. The person shall achieve the Remedy Standard B groundwater PCLE zone response objectives stated in paragraph (1) of this subsection, unless the person demonstrates that an affected property meets the qualifying criteria for one, or a combination, of the modified groundwater response approaches described in paragraphs (2) - (4) of this subsection. A person who satisfactorily demonstrates technical impracticability as described in paragraph (3) of this subsection, may use technical impracticability to establish a plume management zone as described in paragraph (4) of this subsection for instances when a plume management zone would not otherwise be authorized by the executive director, except that the person shall not allow the groundwater plume management zone to expand beyond the existing boundary of the groundwater PCLE zone. A person who uses one, or a combination, of the modified groundwater response approaches shall fulfill the post-response action care obligations described in the approved RAP. A person who uses one, or a combination, of the modified groundwater response approaches which utilizes a physical control(s) shall provide financial assurance as specified in subsections (l) and (m) of this section. (1) General groundwater response objectives. For all groundwater classes, the person must: Cont'd... |
