INERT DISPOSAL AREA - GROUNDWATER
SITE DESCRIPTION
This area encompasses approximately 20 acres that once included an inert (sanitary) landfill, a burning ground, a metal salvage operation, the former Blue Sludge Lagoon, a wastewater sludge drying bed, CEA , and an earthen holding area formerly used to store sludge from Line 3 and Line 800. The Inert Disposal Area is located west of C Road, north of Line 3A in the west central part of the installation.
The inert landfill was in operation from 1941 to September 1992 and employed the trench and fill operation technique. Trenches 1 through 5 were filled primarily with sanitary landfill materials such as unsalvageable or unrecoverable materials (cafeteria and residential refuse and garbage, broken pallets, plastic, tin cans, and scrap wood/lumber paper, cardboard and asbestos insulation in double-lined plastic bags). Ash from OB and incinerations was also placed in the landfill. In 1980 a Part A permit was received for the inert landfill and the Blue Sludge Lagoon. Interim status was granted that year. In 1984 the lagoon holding area was closed following the transfer of the blue sludge to a concrete-lined sludge drying bed, where it remained until January 1997. The excavated area was backfilled and capped with clay and a vegetative cover was established. In 1997, the blue sludge was excavated from the drying bed and deposited into Trench 6. In 1997 explosives- and metals-contaminated soils from a 1993/1994 multi-site sump removal project were placed in Trench 6. Also during 1997, a low permeability synthetic cap was placed over trenches 1 through 5 (approximately 17 acres). This area was seeded in 1998.
The north end of Trench 5 contains special waste, such as ash from the CWP (IAAP-024), EWI (IAAP-025), and OB of explosives and explosives-contaminated wastes. In April 1988 this area was capped and the RCRA closure plan was completed. In February 1997 the plan was amended to address sampling issues. In 1997 during routine sampling radionuclides were found in GW samples and were determined to be within normal background levels for IAAAP and within safe limits.
In 1994 GW monitoring began. Low levels of explosives, VOCs and metals have been found in shallow groundwater (30 feet bgs). High levels of pentachlorophenal (PCP) have been found in one well.
Phase progress will be tracked at this site, but funding requirements will be tracked under site PBC at Iowa. Post PBC costs will be covered under site IAAP-020.
CLEANUP STRATEGY
Under the PBC awarded in 2004, further characterization of the GW will be completed and an FS/Proposed Plan (PP)/ROD under OU4 will be prepared. RA(O) will be required until cleanup requirements are met.
STATUS
RRSE RATING: Low
CONTAMINANTS: Metals, Explosives, VOCs, SVOCs
MEDIA OF CONCERN: Groundwater
COMPLETED IRP PHASE: PA/SI
CURRENT IRP PHASE: RI/FS
FUTURE IRP PHASE: RD, RA(C), RA(O)