Notice of Application for State Water Quality Certification

Public Notice (PN) Date: November 25, 2025               PN Reference Number: POA-2020-00091 v1.0
PN Expiration Date: December 11, 2025                                               Waterway: Prudhoe Bay

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) 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-2020-00091 v1.0 or on or before the public notice expiration date listed above.

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

Project Name: CCP Flare Pit Gravel Replacement

Dates of the proposed activity are planned to begin and end: 01/31/2026 to 05/30/2026

Location: The proposed activity is located within Section 11, T. 11, R. 14, Umiat Meridian, in the North Slope Borough, Alaska.  Project Site (Latitude, Longitude): 70.320033, -148.50015.

Purpose: The purpose of the project is to level the ground under the flare pipelines to remedy subsidence issues and to create access to the flare lines for future maintenance.

Description of Proposed Work: Hilcorp is proposing to place gravel within the gas flare pit under the flare pipelines at the Central Compressor Pad (CCP) in the Prudhoe Bay Unit.

-Install 33,000 cubic yards of gravel around and under the CCP flare pipelines, covering 3.1 acres. Gravel depths will range between 5 and 7 feet.

- Loaders, Bobcats, and dump trucks will be used to place the gravel.

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 the options regarding how to repair current subsidence issues with respect to the piles that support the gas flare pipelines at the Central Compressor Pad in the Prudhoe Bay Unit.

   The alternative to placing gravel for current and future maintenance activities would be to build ice roads as necessary during the winter months and perform maintenance activities from these ice roads. The advantage of building permanent gravel access is that maintenance can be done year-round as needed, and the gravel access will help insulate the underlying wetlands and should help slow down permafrost thaw, therefore reducing the amount of maintenance required.

2. Minimization: Hilcorp is requesting authorization to fill up to 3.1 acres of wetlands. The following will be done to minimize impacts: Fill only the minimum acreage required to safely allow access to lighter-duty vehicles, which will be used for current and future maintenance activities.
3. Mitigation: Hilcorp has avoided and minimized to the extent practicable impacts to wetlands to construct an area that can be used to repair current subsidence issues, as well as facilitating maintenance in the future. This proposed project is located near existing gravel roads and pads, and the impacted wetlands are of diminished value due to flaring activity.

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 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 in order 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 prior to the expiration/closure date of this public notice to ensure that any necessary accommodations can be provided.

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