Notice of Application for State Water Quality Certification

Public Notice (PN) Date: August 20, 2026          PN Reference Number: POA-2026-00362 v1.0
PN Expiration Date: September 4, 2026              Waterway: Putuligayuk River / North Slope Wetlands

Any applicant for a federal license or permit to conduct an activity that might result in a discharge into waters of the United States, in accordance with Section 401 of the Clean Water Act (CWA), must also apply for and obtain certification from the Alaska Department of Environmental Conservation that the discharge will comply with the CWA and the Alaska Water Quality Standards (18 AAC 70). The scope of certification is limited to the water quality-related impacts of the activity subject to the Federal license or permit (40 CFR 121.3, 18 AAC 15.180).

Notice is hereby given that a request for a CWA §401 Water Quality Certification of a Department of the Army Permit application, Corps of Engineers’ PN Reference Number indicated above, has been received[1] for the discharge of dredged and/or fill materials into waters of the United States (WOTUS), including wetlands, as described below, and shown on the project figures/drawings. The public notice and related project figures/drawings are accessible from the DEC website at https://dec.alaska.gov/water/wastewater/.

To comment on the project or request a public hearing with respect to water quality, submit comments via (preferred method) the DEC website https://dec.alaska.gov/commish/public-notices/ or email to the DEC email address: DEC-401Cert@alaska.gov with the subject line referencing Public Notice Reference Number: POA-2026-00362 v1.0 on or before the public notice expiration date listed above.

Applicant: Hilcorp Alaska LLC, Kirsten Hoppe, 3800 Centerpoint Dr Suite 1400, Anchorage, AK 99503, (907) 777-8416; kirsten.hoppe@hilcorp.com

Project Name: Put 29 Access Road and Mine Site

Dates of the proposed activity are planned to begin and end: 10/01/2026 to 10/01/2027

Location: The proposed activity is located within Section 22, T. 11N, R. 14E, Umiat Meridian, in North Slope Borough, Alaska. Section 27, T. 11N, R. 14E, Umiat Meridian, in North Slope Borough, Alaska.  Project Site (Latitude, Longitude): 70.287041, -148.55300.

Purpose: The applicant’s stated purpose is to develop a new gravel source and access road to reach gravel sources, which is necessary for continued oil and gas development, as current gravel sources are being depleted throughout the North Slope.

Description of Proposed Work: The proposed gravel access road will leave an established gravel road that also provides access to Drill site 15, located in the Prudhoe Bay Unit, North Slope of Alaska.  The proposed access road will be approximately 1,000 feet long, 36 feet wide at the surface, maintaining a 2-to-1 slope from the surface of the road to the tundra surface. The proposed access road will be approximately 200 feet wider from the established intersection to allow trucks to safely turn onto the established road. A 24-inch diameter culvert will be placed on the proposed road to allow seasonal water to move, if needed.  The proposed access road is scheduled to be constructed in October 2026.  The mine site will be constructed after the access road is finalized, no sooner than 2027.  The gravel extraction will take place within a 64-acre area.  Overburden berms will have an additional amount of tundra/wetland disturbance. 

In total, approximately 95 acres of tundra wetlands would be impacted to construct the Put 29 Access Road, Mine Site, and overburden areas. The application states that the access road and overburden berms would be removed at the mine's closure, making approximately 30 acres of impacts temporary.

Applicant Proposed Mitigation: The applicant proposes the following mitigation measures to avoid, minimize, and compensate for impacts to waters of the United States from activities involving discharges of dredged or fill material.

1. Avoidance: Hilcorp has reviewed options to avoid construction of the proposed Put 29 Mine Site and Access Road, but the option to construct could not be avoided. Ongoing development in the Prudhoe Bay Unit requires additional sources of gravel. The proposed mine site will be excavated in phases, as needed for gravel. When gravel is used, Hilcorp minimizes the footprint necessary for new pad development by optimizing the well spacing and row layout.Hilcorp also minimizes wetland disturbance by using existing pads whenever possible. However, pad extensions or new pads are required from time to time for exploration drilling and production facilities.
   • The proposed mine site and access road are designed with the minimum footprint consistent with safety and engineering constraints;
   • Hilcorp employs deep mining to reduce surface area disturbance;
   • The construction of the proposed mine site avoids the following impacts:
2. Minimization: The proposed mine site construction has been designed to minimize the area disturbed. The overburden will be removed and placed to maximize the conservation, segregation, and stockpiling of the organic overburden for use in reclamation and restoration projects.

   Once mining is completed, overburden will be placed back into the pit to reduce and buttress side slopes and limit area required for storage.

   • Hilcorp will construct berms around the margin of the proposed mine site to serve as a thermal barrier. This barrier will help to preserve the underlying permafrost and prevent the melting of ice wedges and thermokarsting. Without this insulation, exposed ice wedges may melt and erode back from the edge of the pit with the potential to drain adjacent wetlands. The slope stability gained by this practice will greatly increase the potential for future valuable habitat for avian species. The thermal berms will also prevent the transmission of water, which is a major safety concern in an active mine site. The result of these berms is a net benefit for wetland preservation.
   • Hilcorp minimizes the amount of gravel necessary by minimizing the footprint necessary for additional development wells and associated infrastructure, including providing access to the existing well rows for drilling, completion, and operation of existing wells. Hilcorp designs the footprint of well pads to minimize impacts while still drilling new development wells and working on existing wells. This minimizes the amount of gravel expansion required at this site.
3. Mitigation: Through Avoidance and Minimization, Hilcorp has worked to limit the impact to wetlands.

• Avoid impacting as many lakes, ponds and streams as possible;
• Avoid Anadromous Water crossings to the maximum extent possible;
• Avoid pristine wetlands to develop a new gravel source;
• Will use existing material sites and local existing roads to the maximum extent possible.

• Hilcorp examined permittee-responsible mitigation, including creation/restoration and preservation.Wetland creation/restoration on the North Slope is impracticable because wetlands are primarily developed through permafrost action (taking hundreds of years to develop) and the growing season is only 60 days.This prevents any reasonable success goals from being achieved that would show replacement of lost functions, as required by regulation.
• Hilcorp continues to commit to continued improvement of fish passage routes where existing roads and pads meet streams, creeks, and rivers.
• Hilcorp has avoided potential impacts by methods listed in Section 1 above, and minimized potential impacts by methods listed in Section 2. Avoidance and minimization is proposed to the maximum extent practicable. Hilcorp proposes that the described avoidance and minimization measures satisfy the mitigation requirements under the Corps’ various statutory authorities and therefore proposes that no compensatory mitigation is appropriate or should be required.

After reviewing the application, the Department will evaluate whether the activity will comply with applicable water quality requirements (any limitation, standard, or other requirement under sections 301, 302, 306, and 307 of the CWA, any Federal and state laws or regulations implementing those sections, and any other water quality-related requirement of state law). The Department may certify (or certify with conditions) with reasonable assurance that the activity and any discharge that might result will comply with water quality requirements. The Department also may deny or waive certification.

The permit application and associated documents are available for review. To inquire about or request copies of the documents, contact dec-401cert@alaska.gov or call 907-269-6285.

Disability Reasonable Accommodation Notice:  The State of Alaska, Department of Environmental Conservation, complies with Title II of the Americans with Disabilities Act (ADA) of 1990. If you are a person with a disability who may need special accommodation to participate in this public process, please contact ADA Coordinator Kristin Mabry, kristin.mabry@alaska.gov, 1-907-334-0884; or TDD Relay Service 1-800-770-8973/TTY or dial 711 at least 3 days before the expiration/closure date of this public notice to ensure that any necessary accommodations can be provided.

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