Site Name: DUTCHTOWN TREATMENT PLANT
EPA ID: LAD980879449 EPA Region: 06 Metro Statistical Area: 0760
I10 & HWY 74, DUTCHTOWN, LA 70734
Operable Unit: 01
ROD ID: EPA/ROD/R06-94/088 ROD Date: 06/20/94
Contaminant: Organics
Keys: Oil reclamation-site, groundwater contamination, natural attenuation
Abstract:
Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.
The 5-acre Dutchtown Oil Treatment Facility is an abandoned waste oil reclamation plant located at the intersection of Interstate Highway 10 and Louisiana Highway 74 in Ascension Parish, Louisiana. The site is surrounded by residential and commercial land. The total population located within a 1-mile radius is reported as 1,836, with approximately 369 people within the Dutchtown community. The topography of the site is nearly level with an average elevation of 15 feet above mean sea level. Surface drainage generally flows to the south through the drainage system associated with Highway 74 and Interstate 10. Runoff flows into the Grand Goudine, through a tributary south of the site. The site was used between 1965 and 1982 for waste oil reclamation and is currently inactive.
The site lies in the Mississippi alluvial plain section of the east Gulf Coastal Plain physiographic province. The dominate physiographic feature of the region is the Mississippi River. The major aquifers in the area are fairly extensive beds of thick, permeable, unconsolidated sand that dip slightly to the southwest. The aquifer system is overlain and confined by layers of silt and clay ranging from 75 to 300 feet in thickness.
Dutchtown received waste oils and other waste materials (solvents and petrochemical wastes) from off-site sources, and processed, and distributed products from 1965 through 1982. In November 1984, the Louisiana Department of Environmental Quality began Phase I of a three phase study to characterize the site conditions and presence and extent of contamination. This investigation was followed by Phase II studies, in December 1984, consisting of development of alternative remedial strategies. Phase III concluded the study in June 1985, with the presentation of a closure plan strategy for the site.
An EPA Technical Assistance Team (TAT) conducted site investigations in July 1985, January 1986, and March 1987. Activities included tank inventories, sampling of the holding pond and waste oil pits, and sampling the contents of on-site tanks and a rail tank car.
An emergency response action (ERA) was performed in March 1987 by EPA to clean up a spill resulting from vandalism of the rail tank car and finished oil storage tank. The spilled material was removed, and all storage tank valves were secured. Dutchtown was listed on the NPL on July 17,1987.
Waste characterization was conducted by EPA in December 1987 and January 1988. An Engineering Evaluation/Cost Analysis (EE/CA) was issued in February 1988, which presented an evaluation of removal alternatives for the holding pond, waste oil pit, and storage tanks.
An ERA was conducted from January 1991 through August 1991. During the ERA, the following waste quantities were removed and treated:
--449,810 gallons of waste oil from the holding pond, waste oil pit, and tanks were recovered, blended, and shipped off-site for incineration.
--3,451,999 gallons of stormwater from the waste oil pit and the holding pond were treated in the on-site water treatment unit. A total of 2,400,695 gallons of water were discharged on-site while a total of 1,051,304 gallons of water were routed to the soil washing unit.
--4,400 cubic yards of soil were treated by soil washing on-site to concentrations of less than 4.0 ppm of benzene, stabilized with fly ash and placed as backfill into the pond and pit.
The PRPs and EPA agreed to modify the ERA work plan to include the installation of a French drain in the small waste oil pit to recover contaminated groundwater during the RI/FS process. A total of 75,792 gallons of groundwater were recovered through August 24, 1992. The French drain has not been pumped since August 1992.
This ROD addresses the only and final operable unit for the site. An ERA was completed in 1991 at this site to address threats associated with the holding pond, the waste pits, and the storage tanks and their contents.
The principal wastes posing a threat at the site were the soils, sludge and liquids associated with the holding pond, the small waste oil pit, and the above-ground storage tanks. The soils associated with the sources were treated to concentrations of less than 4.0 ppm of benzene. The areas previously occupied by the holding pond, waste oil pit, and storage tanks were backfilled and covered with a compacted clay cap.
The low level threat materials at the site include surface soils over a limited area of the site. The contamination in the shallow aquifer also poses a low level threat.
Since the principal threat wastes were addressed earlier by the ERA, the actions in this ROD address the low-level wastes and the groundwater contamination.
Remedy:
The selected remedial action for this site addresses the contamination in the groundwater at the site by natural attenuation. The goal of the remedial action is to prevent the migration of contaminants from the shallow contaminated aquifer to the deeper drinking water aquifer. The major components of the selected remedy include:
* Groundwater monitoring to determine if current conditions improve through time, remain constant, or worsen. This includes installing and monitoring both on-site and adjacent private wells;
* Implementing institutional controls in the form of access restrictions, including installing signs, restricting future use of the property, fencing, and deed notices and/or restrictions on use of the groundwater from the site water wells;
* Installing additional monitoring wells to provide data on plume movement;
* Maintaining the existing cap and fence;
* Closing out of the residential well on the Watt's property and drilling of a replacement well; and
* Implementing contingency measures (which include active treatment at the site if groundwater monitoring indicates an increase in contaminant concentrations.