EPA RCRA ID: AKD000643239

On this page:

Cleanup Status
Facility Description
Contaminants at this Facility
Institutional/Engineer Controls
Enforcement and Compliance
Related Information
Contacts for this Facility

Cleanup Status

The Hilcorp North Slope LLC, Prudhoe Bay facility, formerly owned and operated by BP Exploration Alaska, Inc. (BPXA), is an oil and gas production facility located on the North Slope of Alaska. In 2020, Hilcorp North Slope LLC acquired BPXA and assumed operational control of the Prudhoe Bay facility.

There is a hazardous waste storage unit at the facility. The site is being cleaned up because production activities at various locations across the site have led to the release of hazardous waste and hazardous constituents to the environment.

Facility History

Petroleum exploration in the Arctic began in the 1920s. Oil was discovered at Prudhoe Bay in 1968. The oil field opened for large scale development with the completion of the Trans-Alaska Pipeline in 1977. The Prudhoe Bay oil field is situated on state-owned land which is leased and managed by the Alaska Department of Natural Resources.

Oil production is ongoing at the facility. Production fluids (oil, gas, and water) are extracted from the wells and are separated in processing plants. Oil is routed to the Trans-Alaska Pipeline System. Produced water is re-injected into the formation to help maintain reservoir pressure and enhance further oil recovery. The gas is sent down the pipeline with the crude oil (natural gas liquids), injected into the gas cap for enhanced oil recovery, or used for local fuel.

Past Investigation and Cleanup Activities

RCRA Corrective Action activities at this facility are being conducted under the direction of EPA Region 10, pursuant to the 2007 RCRA Corrective Action [3008(h)] Order originally issued to BP Exploration (Alaska) Inc. and assumed by Hilcorp North Slope LLC in 2020 (see Administrative Order on Consent; EPA Docket Number RCRA-10-2007-0222 under "Site Documents" below).

Additionally, the 2021 Hazardous Waste Management Facility Standardized Permit, which has been renewed with Hilcorp North Slope as the permittee, includes conditions governing the corrective action of releases from solid waste management units. The 2007 order is incorporated by reference into the RCRA permit.

Current and Future Work

The order identified more than two thousand (2000) solid waste management units (SWMUs). There have been releases from some of these SWMUs which have resulted in exceedances of the Tier II Action Levels in groundwater, surface water and soils at the facility. (Tier II Action Levels can be found in the Site-Wide Project Work Plan – Part III, Revised Site-Wide Conceptual Site Model and Screening Levels, 2017.)

The order requires submission of multiple RCRA Facility Investigation work plans and reports, followed by Corrective Measure Studies, and, as needed Corrective Measure Implementation. RCRA corrective action work at the facility is anticipated to continue throughout the life of the oil field.

RCRA Facility Investigations have been progressing at three sites: Tuboscope; Sand Dunes Landfill; and the former Pad 13 Waste Pile. Clean up activities at Prudhoe Bay have included pump and treat; removal; and treatability studies involving nanotechnology and bioremediation.

Cleanup actions or environmental indicators characterizing the entire facility are shown below. It is not intended as an extensive list of milestones/activities. This listing, and all the data on this page, come from EPA’s RCRAInfo and are refreshed nightly to this page. For this table and the Cleanup Activities Pertaining to a Portion of the Facility table that follows, a blank in the Status column could mean the action either has not occurred or has not been reported in RCRAInfo.

Cleanup Activities Pertaining to the Entire Facility

Action	Status	Date of Action
(CA725)
(CA750)
(CA400)
(CA550)
(CA800)
(CA900)
(CA999)

^{For definitions of the terms used, hover over or click on the term.}

Cleanup Activities Pertaining to a Portion of the Facility

	Action	Area Name	Date of Action

^{For definitions of the terms used, hover over or click on the term.}

Facility Description

Link to a larger, interactive view of the map.

The Hilcorp North Slope/Prudhoe Bay facility is an oil field of approximately 379 square miles on the North Slope of Alaska. The location is isolated and very sparsely populated. The nearest residential area is the Alaskan Native Village of Nuiqsut, which is 60 miles west of Prudhoe Bay.

The Arctic location of this site greatly impacts facility operations as well as waste management and corrective action. Transportation can be difficult. The area is classified as Arctic desert, cold and dry. Permafrost underlies the site to a depth of approximately 2000 feet.

Structures (buildings, roads, production wells, etc.) must be built on 5 or more feet of gravel to prevent thawing of the ground and settling. The active zone (up to three feet below ground surface) thaws briefly each summer. There is very low topographic relief and numerous shallow lakes form seasonally on the tundra.

There are 56 days of darkness in midwinter. The ecosystem is acutely fragile.

Contaminants at this Facility

Contaminants at this facility are those associated with oil and gas production (petroleum hydrocarbons, freeze inhibitors, drilling fluid additives), as well as contaminants used in the management of a very large facility (jet fuel, lubricants, chlorinated solvents).

Specific contaminants include benzene, toluene, ethylbenzene, xylene, 1,1,1-Trichloroethane, methanol, 1,4-Dioxane, naphthalenes, polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds, barium and other metals.

Institutional and Engineering Controls at this Facility

There are currently no institutional or engineering controls associated with the RCRA order or permit at this facility. The need for them will be determined later in the process.

Institutional and Engineering Controls help ensure human exposure and groundwater migration are under control at a cleanup facility. Where control types have been reported by states and EPA in EPA’s RCRAInfo, they are shown below. Not all control types are needed at all facilities, and some facilities do not require any controls. Where there are blanks, the control types may not be needed, may not be in place, or may not be reported in RCRAInfo.

Are Controls in Place at this Facility?

Control(s) Type		Control(s) in Place?	Areas Subject to Control(s)	Documents available on-line:
(CA 772)	(ID)
	(GC)
	(EP)
	(PR)
(CA 770)	(GW)
(CA 770)

Enforcement and Compliance at this Facility

EPA’s Office of Enforcement and Compliance Assurance provides detailed historical information about enforcement and compliance activities at each RCRA Corrective Action Site in their Enforcement and Compliance Historical Online (ECHO) system.

RCRA Enforcement and Compliance Reports from ECHO

Related Information

For more information about this facility, see these other EPA links:

RCRA information in EPA’s Envirofacts database
Information about this facility submitted to EPA under different environmental programs as reported in EPA’s Facility Registry Services
Alternative Names for this facility as reported by EPA programs in EPA’s Facility Registry Services
Cleanups in My Community provides an interactive map to see EPA cleanups in context with additional data, and lists for downloading data
Search RCRA Corrective Action Sites provides a search feature for Corrective Action Sites

Site Documents

Records Collection for Hilcorp North Slope

Contacts for this Facility

Jennifer Parker (parker.jennifer@epa.gov), Project Manager, 206-553-1900.

Date Last updated: Data on this page was last refreshed on