Site 26 – Western Landfill – NAS Glenview
The former Western Landfill consists of 1.5-acre soil-capped area within a 2.2-acre fenced area. The former Western Landfill was a landfill that may have been a part of the Base Closure and realignment (BRAC) program in the mid-1990s. It is unclear whether the site was transferred to the Navy and avoided the BRAC program or was part of it. Previous investigations defined two primary disposal areas. The landfill was closed in the late 1950s to early 1960s. The former Western Landfill was capped with approximately 3 feet of cover soil and 6 inches of topsoil in 2000 to limit potential exposure to buried waste, and to inhibit the infiltration of precipitation.
The depth of waste in the waste areas is generally an average of 8 feet. Waste from the base was buried or burned in the mid-1950s. The disposed and burned wastes included household refuse, base refuse, and construction debris. Oils, fuels, and solvents may have also been disposed of at the landfill. Previous investigations also identified general refuse mixed with soil in the upper 5 feet outside the extent of the buried waste areas.
Previous investigation results presented in the Final Gray Sites Phase II Report (1996), as well as additional surface soil samples collected in February 1998 are summarized in the Final Engineering Evaluation/Cost Analysis (EE/CA) Report (1999). Contaminant concentrations above NAS Glenview background concentrations and modified risk-based concentrations (MRBCs) were detected in surface soil. The Western Landfill was also previously investigated as part of a 2005 Phase I/II Environmental Site Assessment (ESA). Benzo(a)pyrene was the only parameter detected in one soil sample that exceeded the Illinois Tiered Approach to Corrective Action Objectives (TACO) Tier 1 residential soil remediation objective.
A background study conducted as part of the Baseline Risk Assessment (2017) found concentrations detected above background within surface soils across the site and subsurface soils located outside the waste extent are either naturally occurring metals or are still within anthropogenic ranges reported in regional studies. Due to the fenced and covered nature of Site 26, and the limited occurrence of groundwater, the potential exposures to human receptors are currently limited (i.e., groundwater ingestion) or are controlled (i.e., direct contact). There is a greater chance of encountering waste in subsurface soils within the extent of waste compared to surface soils. Because the presence of waste in a residential area is the remedy driver, risk assessments were not conducted; thus, conservative screening values and Illinois metropolitan background values were used to develop preliminary remediation goals.
Uncertainties with the integrity of the cap, unknown conditions of groundwater adjacent to the landfill, and the potential presence of leachate and soil gas were investigated in 2013 to characterize existing conditions and determine potential landfill closure options. Remedial alternatives include landfill cap improvements, land use controls, and waste excavation.
A remedial design is being prepared to excavate the waste material and contaminated soil for disposal at a permitted landfill and restore the site.
Previous investigations, plans and documentation for this site are: miscellaneous investigations; Engineering Evaluation/Cost Analysis; Environmental Site Assessment; and characterization of existing conditions.
A PP, ROD, and Remedial Design is in process for this site.