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See POLREP 1 in the documents link at www.epaosc.net/torocreek.
EPA involvement with the Toro Creek Oil Spill site was initiated in the summer of 1997 to support the California Department of Fish and Game (CADFG) with cleanup and control actions following vandalism that disabled a State installed oil/water separation system at this historic oil well site. The 1997 event resulted in the discharge of an estimated 3,000 gallons of oil to Toro Creek which impacted the creek for its full 4.5-mile length to the Pacific Ocean. In the years prior to the 1997 spill event, the State Regional Water Quality Control Board (RWQCB) and CADFG had responded to numerous oil discharges to Toro Creek and the Pacific Ocean resulting from primitive and improperly managed private oil/water separation systems on-site.
The State represented to EPA OSC B. Mandel that available State response funds would be exhausted by July 19, 1997, well short of the spill cleanup completion and installation of a new replacement treatment system. This factor, together with an on-site evaluation, led OSC Mandel to determine that the spill met the criteria for funding under the Oil Pollution Act of 1990 (OPA) and secured response funds from the Oil Spill Liability Trust Fund (OSLTF). Federal Project Number (FPN) 117026 was issued by Lt. Ron Chilton, USCG Dist. 11 on July 15, 1997.
The site is in a steep forested canyon (Toro Canyon) near Summerland, Santa Barbara County, CA. The Site is bordered upstream by the Los Padres National Forest, and by private property on the downstream edge. Land use in the Toro Canyon area is a mix of residential and agricultural uses, and as a perennial stream, the Creek provides critical wildlife habitat. Up to 50 gpm of an oil/water mixture discharges at the headwaters of the Creek from an abandoned collapsed oil mine portal dug some 200 feet into the side of the canyon. Historical records indicate this well was constructed in 1882 by excavating a horizontal shaft into the side of Toro Canyon. After the oil “miners” struck a heavy flow of ground water in the shaft, they then built a primitive oil/water separator and sold the water for irrigation downstream.
Geologists have advised that sealing the old horizontally-dug well cannot be successfully accomplished using any known techniques. The flow fluctuates minimally and favored the continued operation of an oil/water separator.
POLREPS 1-11 (through May 1999) summarize the completion of the cleanup actions resulting from the 1997 spill event and describe the design, installation and field modifications to an EPA installed treatment system. The main components of the system include a 800 gpm capacity two clarifier system featuring a primary bottom-less stainless steel separator with underflow baffles for oil-water separation. It was placed directly on top of the seep resulting in an upflow from the bottom into the separator. The separated oil flows into a buried chemhose pipeline which drops 300 feet in a 900 foot run to the collection tank. The tank is a 6,000 gallon capacity conventional double-walled fiberglass underground storage tank (UST) providing secondary containment and is typical of those installed at gasoline stations. It is buried to provide security both from vandals and the threat of wildfire and uses conventional pipe fittings. The entire system has no moving parts and any elements not buried were enclosed in security fencing.
The most recent modification to the treatment system was added in the fall of 2002 and involved the construction of a 25-30 foot high mechanically stabilized segmental retaining wall to protect the upper oil/water separator enclosure from surficial sliding, slumping, and rock fall. The retaining structure was built following recommendations in a slope stability report commissioned by EPA. The retaining wall was necessary, in large part, due to slope instability caused by illegal grading and soil disturbance activities by the current property owner.
Throughout 2003 and 2004, Santa Barbara County inspectors have issued Correction Notices, Stop Work Orders and Notices of Violation to the property owner for grading violations on the property and, in particular, to the steep hillside immediately upslope of the oil/water separator system enclosure [County Grading Ordinance Chapter 14-6(a)]. The retaining wall has fulfilled its design function and, to date, there has been no slide related damage to the enclosure. The County’s rendered opinion, however, is that the illegal grading activity that continues has increased the risk of erosion and slope instability and the County continues to attempt property owner compliance.
Treatment system inspection and maintenance activities have been accomplished under a series of uninterrupted site-specific EPA contracts since FPN inception. The latest contract was awarded in January 2005 and involves tri-weekly site and treatment system inspections/EPA coordination and periodic transfer of accumulated oil to an approved local refinery. When approximately 4,000 gallons of oil is accumulated in the 6,000 gallon UST, a vacuum truck removes about 2,000 gallons of oil from the UST and transports it to a nearby oil refinery for use in asphalt products such as roofing tar, shingles, and road asphalt. The system has collected approximately 65,365 gallons(1,556 bbl) of oil from the fall of 1997 through the fall of 2004. This translates to an approximate 600 gallons of oil/month that has consistently been prevented from entering Toro Creek.
The existing system is working effectively since final modifications in 1998 and we anticipate it will continue to work well indefinitely, barring any unforseen changes in the area due to catastrophic flooding, landslides, changes in flows, or location of the main oil seep. The determination of the OSC continues to be that this response is necessary to abate a substantial threat of discharge of oil into Toro Creek, a navigable water of the U.S. [33 U.S.C. 2702].
On November 15, 2004, EPA OSC lead was transferred from OSC Mandel (retired) to OSC C. Benson.
More complete background information and a more detailed chronology of project specific events can be found in the documents link at www.epaosc.net/torocreek.
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