ASTM E2435-05(2015)

4.1 Intended Application of Guide—This guide is intended for use at properties that are presently developed or proposed for development for residential, commercial, or industrial purposes but which contain chemical-affected soil, groundwater, air, or other environmental media, which may pose an unacceptable risk to human health. This guide can be used as a tool for planning and implementation of property reuse or redevelopment activities at former commercial/industrial facilities, “brownfield” properties, or properties containing naturally occurring, chemical-affected environmental media so as to effectively manage potential human exposures to COCs which might otherwise limit productive use of the property.

4.2 Situations Where This Guide May Be Applied—An engineering control may be needed as part of the development plan when: (1) COCs are present in soil, groundwater, or other environmental media at concentrations posing unacceptable risk(s) to human health per applicable regulatory criteria or a risk-based evaluation; (2) a potentially complete exposure pathway for COCs is likely to exist in the absence of an engineering control or other response measure, and (3) installation and maintenance of the engineering control is determined to be an applicable and cost-effective response action relative to other options. A property should not be excluded from development or redevelopment solely on the basis of chemical-affected media, in general, and chemical-affected groundwater, in particular. If no affected environmental media are identified as having COC concentrations in excess of applicable regulatory standards or risk-based criteria, then engineering controls or other response measures are not required.

4.3 Assumptions for Use of This Guide—For use of this guide, it is assumed that (1) an environmental site assessment has been completed to characterize chemical-affected environmental media, (4.4 Presumptive Use of Engineering Controls—The design basis for any engineering controls installed depends on the risk to be controlled, nevertheless, if no known risk has been identified, the guide may be implemented at the discretion of the site developer. As a conservative measure to reduce or eliminate potential unidentified exposures (e.g., migration of COCs from adjacent properties with known chemical-affected environmental media), the site developer may choose to install engineering controls in the absence of a detailed site characterization and associated risk-based corrective action analysis. Regardless, the site must be sufficiently characterized as to the types and concentrations of the COCs present in order to design and install engineering controls that will effectively mitigate the potentially complete exposure pathway(s) identified for the site. Upon change in land use, the potential for unacceptable risk should be evaluated and the engineering control modified, if so indicated by the results of the evaluation.

4.5 Expected Qualifications for Persons Applying This Guide—Persons applying this guide are expected to be sufficiently knowledgeable in various disciplines, including but not limited to environmental science, property development requirements, or engineering applications, or combination thereof. Such knowledge is required in order to (1) interpret the results of environmental site assessments and risk-based corrective action analyses and (4.6 Intended Compatibility with Other ASTM Guides—This guide is intended to be compatible with other ASTM guides related to the investigation and characterization of chemical-affected property and the management of associated human health risks. This guide is consistent with the practices set forth in these other guides but provides a more focused evaluation on engineering controls as measures to manage risk specifically associated with property development activities.

4.7 Limitations on Use of This Guide—This guide provides a general overview of the procedures for evaluation and selection of engineering controls for use in property development or reuse, but does not address the detailed design, installation, operation, or maintenance of these engineering controls. The user is referred to other, more detailed technical design guidelines for proper implementation of such controls on a site-specific basis.

4.8 Situations Not Addressed—This guide does not address other environmental issues or concerns that are not directly related to property development or reuse but which may be required under applicable laws or regulations. Such uses may include groundwater protection, surface water protection, or ecological concerns.

4.9 Costs Associated with Engineering Controls—The costs for engineering control systems will depend on numerous site specific factors (e.g., area and volume of chemical-affected environmental media, COCs, unacceptable risks to be reduced or eliminated). An exhaustive comparison of costs associated with various engineering control systems is beyond the scope of this guide; however, in order to illustrate the potential cost impact of site development using engineering controls, a case study example is presented in Appendix X4.

1.1 This guide presents general considerations for application of engineering controls to facilitate continued use or redevelopment of properties containing chemical-affected soil, groundwater, or other environmental media, due either to chemical releases or naturally-occurring conditions. This guide is not meant to be prescriptive but rather to present considerations for evaluating technologies capable of addressing potential human exposures associated with chemical-affected environmental media.

1.2 Table 1 lists the considerations that should be taken into account when developing an engineering control in accordance with this guide.