Notice of Application for State Water Quality Certification – POA-2026-00416 v1.0 Indian Creek, Hilcorp Alaska, LLC – Beluga River Gas Storage Pad

Notice of Application for State Water Quality Certification Public Notice (PN) Date: October 7, 2026 PN Reference Number: POA-2026-00416 v1.0 PN Expiration Date: November 6, 2026 Waterway: Indian Creek 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-2026-00416 v1.0 or on or before the public notice expiration date listed above. Applicant: Hilcorp, Stetson Sannes, 3800 Centerpoint Drive, Suite 1400, Anchorage, AK 99524, (907) 564-4665; stetson.sannes@hilcorp.com Project Name: Beluga River Gas Storage Pad Proposed activity is planned to begin and end: 10/26/2026 to 04/30/2027 Location: The proposed activity is located within Section 27, T. 13N, R. 10W, Seward Meridian, in Kenai Peninsula Borough, Alaska. Project Site (Latitude, Longitude): 61.190300, -151.03440. Purpose: The purpose of this project is to construct a new storage pad and infrastructure, supporting expanded natural gas storage in the area. Description of Proposed Work: The proposed project would involve placement of clean gravel fill to support expanded natural gas pipeline operations in the Beluga River Unit. The overall pad would be approximately 7.38 acres in size. Approximately 2.35 acres of palustrine wetlands will be directly filled as a result of this project through the placement of approximately 17,682.3 cubic yards of gravel fill Acreage value and percentage of fill increase to the watershed are provided in Table 1. Total acreage listed is final grade estimates. Table 1: Indian Creek – Frontal Cook Inlet Watershed Total HUC 12 Acreage 46,582 Proposed BRU Gas Storage Pad Gravel Addition Total (acres) 7.38 Proposed BRU Gas Storage Pad Gravel Addition Impacts to Wetlands (acres) 2.35 Percent Increase of Total Gravel Acreage in HUC (%) 0.02% The maps and drawings included with this document provide additional details on the project components. The pad will be sized and graded to accommodate a phased build-out, ultimately supporting up to 10 storage wells and associated surface facilities, though these components will not be permitted or constructed at the time of this application. The BRU Gas Storage pad will require the fill of 2.35 acres of wetlands. The proposed location and design are shown in Figures 1-3 below. The pad will be constructed using a 2V:1H side slope design to reduce the fill footprint to the minimum necessary to accomplish the purpose and need. Approximately 17,682.3 cubic yards of gravel fill material will be placed in the area wetlands. Material Site: The material is currently available; therefore, the project will not involve the development of a new material source. The gravel fill required for construction of the pad expansion will be obtained from an already permitted source. The United States Fish and Wildlife Service National Wetland Inventory classifies the wetlands habitat in the project area as a mix of palustrine scrub-shrub and forested wetlands. These are non-tidal wetlands dominated by woody vegetation that may be either deciduous or coniferous. Figure 4 shows the type and extent of current wetlands mapped at the project site. A riverine system believed to be relatively permanent was found within the surveyed area, flowing in a southerly direction. In the field, this system was noted to have defined banks, be 4 feet (1.2 m) wide, and be approximately 2 inches (5.1 cm) deep, although the depth may vary with local precipitation levels. 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. • Avoidance: Project design has been developed to avoid impacts to wetlands and surface waters wherever practicable. Work limits have been constrained to previously disturbed areas, and construction activities are confined to the minimum footprint necessary for the pad expansion. The proposed project area contains jurisdictional waters of the United States; therefore, complete avoidance is not practicable. Hilcorp proposes to include the following practicable avoidance measures: • Project limits will be delineated with silt fencing or similar material to avoid impacts outside the proposed pad construction area • Work will occur from existing infrastructure to avoid additional temporary impacts to Waters of the U.S. • Minimization: Hilcorp will incorporate the following minimization measures into project design and construction to reduce overall impacts on Waters of the United States: • The pad will be constructed with a minimum 2V:1H side slopes to minimize fill area and impacts to wetlands • Regular pad surface watering will occur during operation to minimize fugitive dust deposition to the area • Existing gravel sources will be used • Where complete avoidance is not feasible, impacts are minimized by implementing erosion and sediment controls, maintaining defined work boundaries, and scheduling activities to reduce disturbance. Standard BMPs will be used to limit soil displacement, manage stormwater, and prevent offsite transport of materials. • Mitigation: To offset any remaining unavoidable impacts, the project will employ site stabilization, revegetation of disturbed areas, and long-term erosion control practices. All mitigation measures will follow agency-approved standards to ensure protection of nearby water resources and overall site recovery 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. ------------------------- cc: (with encl.) John Sargent, USACE Kaitlyn Cafferty, ADF&G USFWS Field Office Kenai Matthew LaCroix, EPA AK Operations ak_fisheries@fws.gov regpagemaster@usace.army.mil [1] Reference submission number: HQR-S0KK-GHAK5; Received: 9/23/2026 1:04:59 PM