JW Dalton Legacy Well Cleanup Project Team, National Petroleum Reserve, Alaska, BLM.
Julia Dougan, Associate State Director
In 2005, accelerated shoreline erosion of the Beaufort Sea in northern Alaska exposed the well casing and breached the reserve pit at the JW Dalton legacy well in the National Petroleum Reserve-Alaska. Release of contamination into the sea has the potential to affect marine life and subsistence resources important to North Slope residents. After securing emergency funding, BLM assembled a team of state and field office specialists to develop and implement an ambitious plan to remove potential environmental hazards from the site. Field work was complicated by the site's remote location and extreme on-site daily temperatures averaging 30 degrees below zero. Despite these obstacles, during the course of five weeks the team removed 9,870 gallons of diesel fuel from the well, plugged the well bore, and excavated, transported and stored 3,000 cubic yards of reserve pit waste. The BLM received formal acceptance and closure of the reserve pit from the State of Alaska in August 2005. Within six months of the cleanup, summer storms had washed the project site into the sea. From start to finish, the project took five months to plan and implement.
Since 2001, staff of BLM's Fairbanks District Office's Arctic Field Office had observed increased rates of shoreline erosion occurring along the northern coastline of NPR-A. In the summer of 2004, staff became increasingly alarmed because shoreline loss at one of these sites - the JW Dalton test well - had exceeded 300 feet during the summer. The well casing was within 15 feet of the water's edge and the reserve pit had been partially breached. Both the well and pit were undercut. Staff specialists predicted that the well and associated reserve pit, which together contained more than 9,000 gallons of diesel fuel and up to 15,000 cubic yards of drilling wastes, would be washed into the ocean during the summer of 2005. Limited sampling of the reserve pit contents by USGS in 1989 and again by the BLM in 2004 showed elevated levels of heavy metals including barium, chromium and arsenic.
The waters off the coast of NPR-A are extremely important to local communities for subsistence activities including whaling, seal hunting and fishing. The loss of the well and reserve pit could have released the diesel fuel, drilling muds and other pollutants into this fragile coastal area. Once inundated, it would have been extremely difficult and costly to plug and abandon the well.
Complicating the operation was the remote location of the well site. The nearest community is more than 50 miles away and the nearest road is more than 100 miles away. Heavy equipment necessary to perform the well plugging and abandonment and reserve pit excavation was transported overland during the winter, with additional materials and supplies delivered by air to an old military installation, appropriately named the Point Lonely DEW Line Site and located approximately 4 miles away from the well. Since work was performed during the winter, a special camp was brought to the site to house workers as normal temperatures in the area average 30 below zero.
Prior to initiating field operations, team members worked closely with the United States Air Force, the Alaska Department of Environmental Conservation and the North Slope Borough, and secured contractors who would perform the actual work.
Besides the perceived environmental impacts and public concern, the regulatory concern for removal of the reserve pit contents was related to the Clean Water Act and Federal and State Solid Waste. The fundamental issue was the discharge of a pollutant to the waters of the United States. The BLM would have been in violation of State of Alaska Solid Waste Regulations had the agency not cleaned up this well. The State of Alaska would have most likely implemented its RCRA and could have mobilized state contractors to do the same work at a substantially increased cost to the BLM. The BLM could have been fined and held responsible for all State costs.
The BLM assembled a special team to accomplish the legacy well cleanup within the tight timetable. The team was composed of staff from BLM's Arctic Field Office and the Alaska State Office's Branch of Energy and Branch of Resources and Planning. Staff from the National Science and Technology Center and National Business Center in Denver provided additional support. Major tasks included:
Site Investigation and Cleanup
In February 2005, staff from the BLM Arctic Field Office and a contractor visited the site to take subsurface samples of the reserve pit. Results indicated that overall, the reserve pit did not contain elevated levels of hydrocarbons. Supplemental sampling conducted in April identified one area near the site of the drill rig/flare pit that did contain elevated levels of diesel fuel. Of the 14 priority metal pollutants analyzed, none appeared to be significantly elevated, although barium had been detected at relatively high levels.
Based upon the results of the site investigation, rough estimates of the volume of material to be removed were revised to less than 4,000 cubic yards. Waste storage and treatment options were reanalyzed. The cost estimate for the initial phase of the project came to $7.8 million.
More than 300 truck loads of material were moved the 4 miles from the pit site to the storage location. Work was completed at the site on May 4, 2005. All equipment was safely transported back to Point Lonely or to Prudhoe Bay by May 11. Over the course of the summer, members of the team returned to the storage cell to conduct stockpile maintenance and then to dewater the waste materials and monitor the well site. Care had to be taken so that threatened and endangered eider species were not attracted to or caught in the covering of the treatment cells.
In August 2005, DEC conducted its final inspection of the JW Dalton well site and granted formal closure of the site. Follow-up visits to the site were hampered by poor weather through early September. In mid-September, inspectors visited the site and found that the entire well site and most of the reserve pit were in the ocean.
On May 24, 2006, the BLM was notified by the North Slope Borough that all JW Dalton waste material stored at Point Lonely met solid waste requirements for disposal at their landfill facility at Prudhoe Bay. By dewatering and filtering out pollutants from the waste material, disposal costs will be reduced by two-thirds. The BLM awaits funding for the transportation and disposal of the reserve pit waste material.
As a result of the JW Dalton legacy well cleanup, the BLM initiated a systematic approach to inventory other old government drilled abandoned well sites in NPR-A to ascertain if any other sites and reserve pits were in danger of release to the Beaufort Sea. Ten additional sites of concern were identified, and as part of this effort, the BLM began a sampling program to characterize the reserve pit contents of the top three priority well sites and to determine the volume of materials present.
Bob Schneider, Field Manager, Northern District Office
U.S. Department of the Interior
Greening of the Interior