Notice of Application for State Water Quality Certification

Public Notice (PN) Date: February 21, 2025   PN Reference Number: POA-2001-01082 v1.0
PN Expiration Date: March 23, 2025                                                Waterway: Beaufort Sea

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-2001-01082 v1.0 or on or before the public notice expiration date listed above.

Applicant: Hilcorp Alaska, 3800 Centerpoint Dr,Ste. 1400, Anchorage, AK 99503, (907) 564-5382; erin.bragg@hilcorp.com

Project Name: PTU Screeding and Dredging

Dates of the proposed activity are planned to begin and end: 07/01/2025 to 11/01/2026

Location: The proposed activity is located within Section 34, T. 10N, R. 23E, Umiat Meridian, in North Slope Borough, Alaska. Project Site (Latitude, Longitude): 70.174336, -146.25643.

Purpose: The applicant’s stated purpose is to conduct screeding and dredging at the Point Thompson Unit (PTU) Central Pad Service Pier. to maintain sufficient navigable water depths to allow for safe barge access and to allow for the safe loading and unloading of equipment from barges at the service pier for the Point Thompson Unit. In instances when a barge must be grounded on the seabed to allow one or more heavy objects to be transferred between the barge and the dock, the seabed must be screeded and/or dredged to provide the proper level surface to support the barge. Screeding and/or dredging will be conducted to provide the required seabed depth profile.

Description of Proposed Work: The proposed project would involve screeding and dredging during the summers of 2025 and 2026 in front of the service pier at the Point Thompson Unit to maintain navigable barge access. The service pier is located approximately 70 feet offshore from the central pad and is where screeding would take place. The area where screeding and/or dredging would occur is an estimated 154,200 square feet (3.53 acres) area of subtidal seafloor. The dredging and screeding area starts at the end of the service pier and goes seaward (north) approximately 500 feet and east and west approximately 450 feet. The screeding-specific area is approximately 815’ x 120’ (2.25 acres).

Screeding involves redistributing the existing marine sediment to provide the required seabed depth profile for the barges. This is accomplished by dragging a beam fixed to the bottom of a barge to redistribute and level the marine sediments. The beam is mounted on a barge propelled by a tug, with the height of the beam set to the desired depth. Hilcorp anticipates using a Deck Cargo Barge with a screed kit attached.  The sediments around the PTU Service Pier are subject to transport by waves, currents, ice, and barge propeller wash. As a result, screeding and/or dredging are necessary to maintain navigable water depths.

Barges transporting equipment, materials, or supplies to the service pier require a minimum of 5.5 feet- MLLW depth to access the pier. To achieve the needed seabed profile, dredged material would be removed via an excavator to a barge deck where the material would be drained. The drained material would be taken back to the dock where a loader would place the material in a rock truck and transport it to an existing PTU gravel storage pad. Approximately 5,740 cubic yards of material would be distributed or removed as part of the project. These construction activities would impact approximately 5.78 acres of ocean waters.

Additional Information: The proposed project will require the following additional authorizations: Alaska Department of Natural Resources, Department of Oil and Gas Lease on Operations North Slope Amendment (Not Submitted); North Slope Borough Administrative Approval (Not Submitted); United States Fish and Wildlife Service Marine Mammal Protection Act Incidental Take Regulation (LOA 24-INC-04, Issued); United States Fish and Wildlife Service Marine Mammal Protection Act Intentional Take Regulation (LOA 23-INT-11, Issued).

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 dredging adjacent to the Point Thompson Unit service pier. However, the area experiences sedimentation due to Beaufort Sea currents, storms, and the addition of sediment into the water column from area rivers and runoff. If project-specific dredging does not occur, the operability and initial purpose for the construction of the pier may no longer be met and use of the dock for barge and other vessel access may not be able to continue. Additionally, this work was previously permitted during development in 2012.No new or increased impacts to the environment from these activities are anticipated.Therefore, Hilcorp has determined that complete avoidance of impacts is not practicable.
2. Minimization: Hilcorp has stated that the proposed project-specific dredging would be limited to the current scope, area, and volumes necessary to accommodate vessels utilizing the Point Thompson Unit. Hilcorp proposes to screed and dredge approximately 5,740 cubic yards of material. The design depths reflect the necessary hull draft for large sea-lift operations. The requested volumes reflect the minimum dredging/screeding necessary to meet operational design depths for the facility. Screeding and dredging will only be conducted to provide utilization of the Point Thompson Unit service pier as was previously permitted in the original approval of the facility by the USACE. Hilcorp states that they have avoided and minimized, to the extent practicable, impacts to the waters of the US to access the Point Thompson Unit service pier.
3. Mitigation: The proposed project-specific dredging will be limited to the current scope, area, and volumes necessary to accommodate vessels utilizing PTU. Hilcorp proposes to screed and dredge no more than 5,740 cy of material annually.The design depths reflect the hull draft for large sea-lift operations. The requested volumes reflect the minimum dredging that may be necessary annually or to the current design depth for PTU and its approach. Screeding and dredging will only be conducted as necessary to provide utilization of the PTU dock as was previously permitted in the original approval by the ADEC/USACE.

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 Mike Kruzinski at 907-334-0884, Mike.Kruzinski@alaska.gov 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.