Cleanup Project Bulletin
Cascade Corporation
Project Overview
The Cascade Corporation site is located at 2201 NE 201st Avenue in Troutdale, Oregon. Cascade has manufactured specialized lift truck attachments at the site since 1956. The plant and surrounding paved areas occupy about eight acres of the 47 acre property. Cascade has historically conducted a variety of industrial processes, including machining, carburizing heat treatment, nickel and hard chrome plating and painting.
Chlorinated solvents were used for parts cleaning through 1975. Two underground tanks located near the northern property boundary were used to store waste oils containing solvents. Soil contamination was found during removal of the tanks in 1988. Follow-up investigations confirmed contamination of groundwater in a shallow, unconfined aquifer. In 1989, DEQ and Cascade signed a consent order to complete a remedial investigation and feasibility study (RI/FS). The RI/FS was completed in 1996.
During the RI/FS, Cascade implemented several interim actions to limit the spread of groundwater contamination. The interim cleanup actions included removal of soil contamination, installing and operating four extraction wells on the northern property boundary, and installing a 400-foot long groundwater recovery trench north of the facility. Over 45 million gallons of contaminated groundwater containing approximately 460 pounds of solvents have been removed by Cascade since interim cleanup started in 1991.
In December 1996, DEQ issued a remedial action record of decision (ROD) for the Cascade Corporation facility. The remedy requires additional groundwater extraction on-site, injection of air into the shallow groundwater aquifer to volatilize solvents from the water, and extraction of solvent vapors from the soil. A consent order specifying the requirements for implementing the remedy was issued to Cascade on April 2, 1997.
Remedy Implementation Progress
Construction of the Phase 1 remedy components has been completed. Phase 1 start up was performed in a phased manner between March and May 1998. The groundwater extraction wells were brought on-line first, followed by the soil vapor extraction well system (SVE), and then the air sparging system. Each of these systems are described below.Groundwater. The on-site groundwater extraction system includes 18 wells. Groundwater extraction rates are approximately 16 gallons per minute (gpm) which is less than the estimated design rate of 45 gpm. Since start-up in March 1998, a total of 1.7 million gallons of groundwater containing approximately 20 pounds of VOCs have been removed and treated.
Soil Vapor Extraction. The SVE system includes 21 extraction wells. The system is removing 1500 to 1700 cubic feet per minute (cfm) of soil vapor from the subsurface. The VOC mass removal rate from the SVE system is approximately 2 pounds per day. A total of 130 pounds of VOCs have been removed since start up.
Air Sparging System. An air sparging pilot test using two air injection wells began on May 12th. Air is being injected into the aquifer to volatilize VOCs from groundwater where they are removed by the SVE system. The objective of the air sparging test is to determine whether air sparging will significantly increase the rate of VOC mass removal from soil and groundwater.
Phase 1 will be evaluated for expansion in December 1998.