Region 8's Response Unit received a NRC Report (#1165618) on December 6th, 2016 of a 6-inch crude pipeline release in North Dakota on Ash Coulee Creek 9-miles upstream from the confluence with the Little Missouri River. The incident occurred on December 5th, 2016 at 10:30AM local time. The pipeline was shut-in and an underflow dam followed by boom sets were placed downstream from the pipeline and any effected water.

An On-Scene Coordinator was deployed to the site on December 8th, 2016.

1. Ensure safety of responders

2. Recover spilled oil

3.  Minimize impact to livestock and wildlife

4.  Remove recoverable oil from impacted areas of Ash Coulee Creek

5.  Maintain accountability of personnel and equipment

6.  Inform key stakeholders of response activities

7.  Repair pipeline

Response teams are currently focused on:  containment, recovery operations, reconnaissance and planning.

Containment and Recovery:  The spill has largely been contained immediately downstream from the point of release.  A series of two underflow dams have been constructed at the point of release.  Oil is collected at the underflow dams and removed directly with a vacuum truck and/or skimmer.  The skimmers have been covered by a tent and are heated to prevent freezing. 

An additional underflow dam was constructed approximately one mile from the point of release (Control Point #1).  Skimming operations are conducted at this location as well.  Based on aerial reconnaissance, an estimated 70 percent of oil released is contained between the point of release and Control Point #1.  Additional underflow dams have been constructed further downstream (Control Points #2 and #3).  The leading edge of the spill is at river mile 4.5, just past Control Point #2.  Due to extreme cold and ice conditions, the leading edge of the spill does not appear to have migrated.

Due to extreme low temperatures the surface of the creek has frozen over, making it difficult to establish spill volume estimates.  Based on aerial reconnaissance, it is estimated that 3,100 bbls may have been released into the Ash Coulee Creek. An estimate for oil remaining in soil on the slough is still under evaluation. The initial estimate for oil released in the soil is 1,100 bbls, however this estimate is highly uncertain. These estimates may change as assessment continues. 

Estimated oil recovered to date: 983 bbls from water

Unified Command, which includes response teams from Belle Fourche Pipeline, the North Dakota Department of Health, and the U.S. Environmental Protection Agency, has proposed a test burn to supplement the ongoing mechanical removal of oil from the creek. An in-situ or controlled burn is a removal technique that allows for an efficient and more complete removal of oil during a cold weather recovery. At Ash Coulee Creek extreme low temperatures and oil trapped under ice make it difficult to use only mechanical methods of removal. The test burn will evaluate if an in situ burn results in an efficient and more complete removal of residual oil, especially from difficult to access locations. The proposed test in-situ burn will take place today, December 15 and areas for the proposed test will be limited to 20‐yards increments created by sand bag underflow dams on private property.  The test burn is expected to last for one hour and measures will be taken to contain the fire to designated locations.  If determined effective, controlled burning may be employed at other locations in the creek over the next several days as a way to eliminate oil that cannot be recovered mechanically and prevent additional saturation of soils and vegetation, and potential impacts to wildlife and downstream water resources.

Air quality will be monitored before, during and after the test burn to ensure safety of workers and nearby residents.  Although some particulate matter will be associated with the fire, the burn will reduce volatile emissions of hydrocarbons from the oil and is intended to secure a more complete elimination of oil from the creek.  A smoke plume may be visible for roughly five miles.  Local communities and officials, including the Billings County Sheriff and County Emergency Manager and Fire Department have been notified and county response authorities will also be present at the site during the test burn.

Unified Command conducted a test burn to supplement the ongoing mechanical removal of oil from the creek. The test in-situ burn took place on December 15th and was limited to a 20-yard reach.  The test burn lasted for approximately 30 minutes and remained contained during the entire process.  Wind speed and direction were evaluated prior to the burn to ensure that the generated smoke plume would not impact on-site personnel and or local residents.  Air monitoring data was collected throughout the burn and indicated no risk to the surrounding communities. 

Based on field observations and qualitative data, the burn was determined to be an effective measure to address oil above and below layers of ice and snow within the creek. It was estimated that approximately 85% of the oil within the test reach was burned before the burn was extinguished.  Beginning December 16th in-situ burning in conjunction with ongoing oil skimming operations will be conducted to remove and mitigate oil along the impacted areas of the creek. 

Operations continue performing recovery at various underflow dam collection points, as accessible along the Ash Coulee as well as at the release location.  To-date a total of 2,269.5 barrels (95,319 gallons) of oil has been recovered, of which 1,522 barrels (63,924 gallons) was recovered at the release location. 

Controlled in-situ burns have been conducted in areas along the Ash Coulee where recovery operations cannot be conducted due to terrain and provided that weather conditions are appropriate.  Wind speed and direction are evaluated prior to ignition to ensure an appropriately controlled in-situ burn.  During in-situ burns, air monitoring is conducted in the areas of site personnel, down-wind in the vicinity of the plume, and at the nearest residence.  If air monitoring personnel detect concentrations above a specific action level, personal protective equipment is employed or the burn is extinguished depending upon the receptor.