On February 11, 2008, Marathon Pipe Line LLC (MPL) notifed the National Response Center (NRC) of a discharge from a 24-inch crude oil pipeline in Winchester, Clark County, Kentucky (NRC Report No. 862058). The pipeline was shutdown immediately after the release was initially detected on a farm along Tangleridge Lane in Clark County, Kentucky at approximately 9:30 a.m. on February 11, 2008. The oil was discovered to be exiting via a spring into an unnamed ditch, which subsequently drained through a farm pond and into a sinkhole, about 200 feet downstream of the pond. An immediate response by the Clark County Fire Department, the Clark County Road Department and Winchester-Clark County Emergency Management was effective at containing the spill in the ditch and pond and preventing it from entering the sinkhole. EPA Region 4 OSC Art Smith and the Superfund Technical Assistance and Response Team (START) contractor TN & Associates were dispatched to investigate the extent of the oil spill and to document oil removal actions by MPL, who is the Responsible Party (RP).
At the present time, the discharge of oil is contained to three properties immediately downgradient of the pipeline section where the release occurred. Although the initial NRC report indicated a potential release of 200 barrels of crude oil, MPL estimates that the total volume discharged to the environment is less than 70 barrels (approximately 3,000 gallons.
Based on all available information, EPA and KDEP do not consider that the oil discharge poses a threat to the community. Plans are in place to further investigate local water resources to evaluate effects of the oil spill on the environment. This work will be performed by MPL, under the direction of KDEP, who assumed lead agency responsibility for the response, effective 02/14/08.
Activities conducted during this reporting period include the following:
• An underflow dam constructed immediately downstream of the seep first identified on 02/11 is highly effective at mitigating downstream impacts. However, precipitation events on 02/11 and 02/12 caused surface runoff which threatened to overwhelm the containment of the oil spill at which had reeached the farm pond. MPL's contractors attempted to close the pond outfall, but water continued to seep through along the bottom of the existing outlet pipe. An oily sheen was observed on surface water downstream flowing from the pond. Removal of free product on the pond surface, and lowering the water surface elevation in the pond mitigated the oil discharge from the pond by 02/14. As a precaution, two additional underflow dams were constructed downstream of the pond to prevent oil product from entering the sinkhole.
• On 02/12, MPL began excavating along the pipeline to identify the leak location. The leak location was identified on 02/13. The leak consisted of a small drip at a weld, allowing for product to accumulate in the subsurface and flow through the limestone rock formation to the spring where the crude oil was first detected. Repairs were made, allowing the pipeline to resume normal operations on 02/13. However, visual examination of the repaired section on 02/14 revealed a minor leak, requring the pipeline to shutdown again on 02/15. The affected section will be cut out and replaced, prior to resumption of pipeline operations. The US DOT Pipeline Safety and Hazardous Materials Administration (PHSMA) is monitoring the effectiveness of the repairs and is responsible for issuing approval to resume operations.
• On 02/13, evidence of oil sheening at an offsite location was reported to EPA and KDEP by an adjacent property owner. Further investigation revealed that this discharge may have been ongoing for an extended period, based on reports from the property owner. Pockets of crude oil were observed in a marshy area at this location. The intermittent surface water feature emanating from a spring mostly exhibited a heavy sheen with some weathered crude oil. The downstream impacts of this release were unnoticeable at the confluence of the intermittent stream and Lower Howard Creek.
Planned removal activities include:
• continued containment and removal of the discharged oil.
• complete repair of the damaged pipeline
• continued pumping of water to lower the pond water level, until an upgraded outlet control structure has been constructed.
• removal of oil contaminated soil and debris, as necessary.
• construction of a siphon dam at the pond outlet
• environmental sampling of surface water downstream of identified oil seeps
• completing a survey of the local area for springs at elevations below the affected section of the pipeline where additional oil seeps might surface
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