CO0042729 - Laserfiche WebLink

Home Browse Search

PROVEN TECHNOLOGIES AND REMEDIES GUIDANCE-REMEDIATION OF METALS IN SOIL 8.0 DESIGN AND IMPLEMENTATION OF CONTAINMENT/CAPPING ALTERNATIVE This chapter describes the approach that could be used to select the type of cover/cap to be installed at a site and to prepare a cap/cover design and implementation plan. It provides general guidelines regarding cover/cap selection and design that are intended to enhance the efficiency of, but not replace, site-specific decisions made on the basis of individual site characteristics, applicable laws and regulations, and the principles of good engineering design. The intent of this chapter is to provide guidance to the preparer of a design and implementation plan that will help them identify and design a cover/cap system that is fully protective of human health and the environment, achieves site-specific remedial action objectives (RAOs), is compatible with reasonably foreseeable future uses of the site, and which meets specific requirements of the regulatory process under which the site is being addressed. Under the PT&R approach, a basic cap design for the least complex sites must effectively eliminate ingestion, inhalation, and dermal contact as complete routes of exposure and preclude contaminant dispersion through the air and surface water run-off. As site complexity increases, or where site-specific circumstances produce additional objectives, this chapter provides the latitude to pursue a full range of design options. 8.1 DESIGN OBJECTIVES For some of the sites addressed under the PT&R process where containment/capping has been selected as the preferred remedy in the remedy selection document, the protection of human health and the environment can be assured by meeting the following RAOs: • Elimination of receptor contact with contaminants in shallow soil which exceed cleanup goals; and • Isolation of contaminated soil to eliminate wind and surface water dispersion. As a result, the installation of a soil cover, or a cover constructed of a single layer of asphalt and/or concrete, along with provisions for appropriate long-term stewardship may be adequate. For other sites, additional RAOs may be identified in the remedy selection document. These additional RAOs may result in the need to adopt a more complex design. Often, site-specific considerations may affect the specific design selected for a site. The considerations may be associated with planned development or future use of the property, or may be connected to the site's physical location, features, or surroundings. Some examples include: • Anticipated future use of the property (both short and long term); 39