The site is located at 140 Roosevelt Drive in Derby Connecticut the Hull Dye and Print industrial complex.
On August 25, 1994, USEPA received a call from the Connecticut Department of Environmental Protection (DEP), requesting access to the Oil Spill Liability Trust Fund in order to conduct removal actions to prevent the continuing discharge of oil to the Housatonic River from the 140 Roosevelt Drive facility.
The responding EPA OSC opened FPN # 014504 and with the National Pollution Fund Center (NPFC) Case Officer, prepared a Pollution Removal Funding Authorization (PRFA) which was issued to the DEP to initiate cleanup operations. In the area of the riverbank immediately down gradient of the facility where the subsurface oil was leaching to the river, oil saturated sediment and approximately 10,000 gallons of free product was removed. An interceptor trench and recovery well system were then installed to contain and collect additional oil, thereby preventing the continued discharge to the river. This system (Derby-1) is still operating and recovering oil on an intermittent basis.
On August 20, 1999, DEP received a new report of an oil sheen on the river, apparently emanating from the tailrace of the facility. A subsequent investigation indicated that the oil was migrating under and around the facility from a source area on the other side of the facility (location of historic oil storage tanks that had been removed in 1994). Removal operations to recover oil from the source area began on December 6, 1999.
This oil recovery system (Derby-2) consists of five recovery wells (four of the five also contain groundwater depression pumps) within an interceptor trench. Each of the recovery wells contains a skimmer that recovers oil into a 50 gallon day tank, which is then pumped into an above ground storage tank and subsequently shipped off site for disposal. The groundwater is pumped to a frac tank and then through activated carbon cells prior to discharge to the River. Although the wells are continuously recovering subsurface oil, there has still been significant sheening emanating from the tailrace. Hard containment boom and sorbent boom, which is changed out on a regular basis, are used to contain the oil from reaching the river.
Tasks that were conducted under the auspices of the DEP and their contractors under the PRFA include: regular site inspections; ongoing system maintenance; groundwater treatment and discharge; and periodic transportation and disposal of collected oil, spent carbon, and boom. Due to the additional workload presented by some of the recommendations made by consulting engineers and in light of DEP’s regular workload, EPA and DEP agreed that EPA assume responsibility for oversite of any site work as of July 19, 2005. EPA’s contractors have been performing regular maintenance work and updating the system since that time in order to obtain maximum efficiency and oil recovery.
On March 28, 2006, DEP notified EPA of a significant discharge of oil from the facility that occurred early that morning. Oil sheens on the river and staining of the shoreline was evident for at least one mile downstream of the facility. After investigating the scene, it appeared that the canal up-gradient of the facility had released its contents through the facility and picked up an unknown quantity of oil prior to releasing into the Housatonic River. The water in the canal had been used in the past to power the electric producing turbines housed within the building. It is still unclear however why the water in the canal was released. EPA and its contractors worked on cleaning up the tailrace which included power washing the oil soaked rock and absorbing whatever free product was available with sorbent boom, pads, and snare. Additional sorbent boom was placed along the river bank for approximately one mile to absorb any oil that continued to leach out of the bank and containment boom was placed at appropriate downstream locations to contain any pockets of floating oil.
EPA’s immediate plans include the blocking of the pipes that carry water from the canal and through the facility, so an inadvertent release does not reoccur. Since greater amounts of oil appear to be leaching out of the tailrace walls since the March release, options are being evaluated to block the river water from the tailrace, effectively dewatering the race. This will allow EPA to investigate the walls and interior of the race and potentially more effectively recover oil from behind the race walls. This is in contrast to previous plans being considered to dam the race, keeping water at an even head in back of the dam, within the race.
Due to limited oil recovery, the recovery well at Derby (1) was recently put on a timer to ensure that when it is operating, oil is being recovered as opposed to groundwater. The efficiency of the remaining five wells is being examined and timers will be installed on those that are not showing constant oil recovery.
Additional planned activities for the summer of 2006 include soil borings, the installation of additional monitoring wells, and potentially adding a new recovery well(s) and improving the efficiency of the water treatment system.
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