Jump to main content.

Local Navigation

Record of Decision System (RODS)



Address:  00-ALC/EM 
City & State:  HILL AFB  UT  84056
EPA ID:  UT0571724350
EPA Region:  08
NPL Status:  Currently on the Final NPL
ROD Type:  Record of Decision
ROD ID:  EPA/ROD/R08-92/066
ROD Date:  09/25/1992
Operable Unit(s):  03
Media:  Soil
Contaminant:  Inorganics
Abstract:  SITE HISTORY/DESCRIPTION: The 6,700-acre Hill Air Force Base (AFB) is located in northcentral Utah, covering portions of Davis and Weber Counties. Surrounding land use is predominantly industrial. Shallow ground water in the area is used only for agricultural purposes, and there are no wells that currently supply drinking water from the shallow aquifer. This site is part of OU3 in the southeastern portion of the Base, which also includes the Industrial Waste Treatment Plant (IWTP), sludge beds, Berman Pond, Ponds 1 and 3, Buildings 510 and 514, and a contaminated ground water area. There are several areas of the Base where past disposal practices and spills contaminated both the soil and ground water. The Air Force has grouped geographically adjacent contaminated areas into seven OUs. The Sodium Hydroxide Tank Site is a 29,000-square-foot area that surrounds two 12,000-gallon underground storage tanks (USTs) constructed in the 1950's. The tanks, approximately 5 feet below the ground surface, are used to store sodium hydroxide solution, which is used as an additive in wastewater treatment at the IWTP. In 1980, an estimated 150,000 gallons of solution leakedfrom the inlet connections to the tanks over a 1-year period. A second series of leaks occurred in 1984, releasing approximately 132,000 gallons. Sampling investigations revealed high soil Ph and conductivities, indicating that most of the contamination is probably at a depth of 25 to 40 feet below surface. The presence of the sodium hydroxide solution in the ground water is uncertain and will be investigated in future remedial investigations. A 1991 ROD addressed the interim remediation of OU2 subsurface soil and ground water. This interim ROD limits further degradation of ground water quality as a result of sodium hydroxide migration through the unsaturated zone. Future RODs will address a final remedy for contaminated soil and ground water at OU3 and other OUs at the Base. The primary contaminant of concern affecting the soil is aninorganic, sodium hydroxide. PERFORMANCE STANDARDS OR GOALS: Chemical- specific performance standards for this interim action will be specified in the final ROD for all of OU3. This ROD invokes an ARAR waiver on the basis that this is part of an interim remedy; therefore, RCRA closure requirements will not be attained. INSTITUTIONAL CONTROLS: Not provided.
Remedy:  SELECTED REMEDIAL ACTION: The selected interim remedial action for this site includes removing two underground storage tanks; backfilling the excavated area with the previously excavated soil and clean fill; and constructing a 29,000 square foot sloped temporary asphalt cap at the ground surface after removal of the tanks to ensure drainage of precipitation into the existing stormwater system. The tank removal project will be conducted under a state permit and administered by the state under its Underground Storage Tank (UST) program, under a stateissued permit, which will regulate decontamination and proper disposal of the tanks and their associated piping, as well as testing for contamination of the native soil underlying the tanks and piping. The estimated present worth cost for this interim remedial action is $55,343, which includes an annual O&M cost of $540 for 3 years.
Text:  View full-text ROD [ 39K ]
To download a full-text ROD, right click on the above link and select Save Link As. A full-text ROD is in PDF format. Please note that download time may be extended given the size of the full-text document. File size is noted in kilobytes (K) or megabytes (M) next to the download link.
About Adobe Portable Document Format
Return to Search Results    Return to RODS List

OSWER Home | Superfund Home

Jump to main content.