Notice of Application for State Water Quality Certification

Public Notice (PN) Date: October 7, 2026                 PN Reference Number: POA-2022-00357 v1.0
PN Expiration Date: November 6, 2026                    Waterway: Sagavanirktok River

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-2022-00357 v1.0 or on or before the public notice expiration date listed above.

Applicant: Alyeska Pipeline Service Company, Wesley Willson, 615 Bidwill Avenue, Fairbanks, AK 997017574, (907) 450-4112; wes.willson@alyeska-pipeline.com

Project Name: Trans Alaska Pipeline System (TAPS), Bank Erosion Mitigation (Pipeline Milepost 20)

The proposed activity is planned to begin and end: 10/15/2026 to 12/31/2027

Location: The proposed activity is located within Section 5, T. 7N, R. 14E, Umiat Meridian, in North Slope Borough, Alaska. Project Site (Latitude, Longitude): 69.98800, -148.68100.

Purpose: The purpose of this work is to restore a buffer zone along an inactive gravel pit adjacent to the Sagavanirktok (Sag) River to protect the integrity of the shallow buried Trans Alaska Pipeline System (TAPS).

Description of Proposed Work: An eroding buffer strip between the gravel pit and the Sag River will be restored along the entire eroding length of the pit. In-situ alluvial material will be scraped from a gravel bar to the east and used to widen the buffer strip. Along with the restored buffer, short, buried rock sills will be installed to arrest future erosion towards the gravel pit. To access the work area, temporary gravel ramps will be installed on previously disturbed locations. After construction, the ramps will be removed, and the sites restored to their prior condition.

The work consists of: Gravel mining from the Sag River gravel bar and Installation of gravel and riprap structures to protect TAPS.

The applicant proposes to discharge approximately 10,000 cubic yards of alluvial gravel in up to 7 acres below the ordinary high-water mark of the Sagavanirktok River to mine gravel from a gravel bar and discharge 9,500 cubic yards of the mined gravel in 2 acres of the Sagavanirktok River to create a stabilized buffer to protect an old gravel pit pond and the buried pipeline. A temporary berm would be created from streambed material to protect the gravel mining site.

 This work would be implemented in late fall when the river stage is typically very low and local seasonal side channels are frozen or dry. Depending on field conditions, isolated areas of groundwater seepage may be encountered, especially in the early stages of construction. Therefore, it is anticipated that the work area would be mostly frozen and/or dry. A stream diversion or a temporary installation of culverts may be necessary to minimize impacts on water quality. Total impacts are up to 9 acres of the Sagavanirktok River. Equipment would be staged above the ordinary high-water mark, in the adjacent uplands.

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: The applicant states that Alyeska is avoiding wetlands as much as possible for the storage sites of material; these storage sites have been identified by Alyeska's Environmental Coordinators as upland areas adjacent to the Sagavanirktok River. Alyeska is also choosing travel routes to avoid any wetlands and create minimal impacts on all vegetation.

   Alyeska plans to use several BMPs to protect water quality in the Sagavanirktok River as described below.

• Sustainable Quantity of Gravel Mined: Alyeska will mine volumes of depositional gravel that can be recharged by the Sagavanirktok River within 2 to 4 years.
• Mining only during low water levels in the Sagavanirktok River: Alyeska plans to mine only during low water conditions using an excavator and bulldozer to excavate/scrape the top of the gravel bars above the water line. Mining will not be conducted in any flowing water. If water levels rise in the Sagavanirktok River, Alyeska will cease mining and remove equipment from the site.
• Limited Access to the Gravel Bar: Alyeska will route the temporary gravel (or snow) ramp to avoid any small, isolated water or very minor river braids. Gravel ramps will be installed if needed for equipment access from the end of existing access roads and then removed after mining is completed.
• Mining Less Than +/- 3 Feet below surface: Alyeska will only excavate above the elevation of the active water in the Sagavanirktok (water table), to an approximate depth of 3 feet. It is anticipated that most mining operations will be 1 foot to 3 feet below surface level. Material will be removed in shallow, smooth, even lifts.
• 50-foot Setback from the Riverbank: Alyeska will not mine any closer than 50 feet from the existing bank of the Sagavanirktok River.
• 30-foot Setback from the Active Water Level of the River: Alyeska will not perform any mining activities closer than 30 feet from the active water level of the Sagavanirktok River.
• Isolation Berm: Alyeska will construct a 3-foot-high gravel isolation berm.
• Restrict Heavy Equipment Use to Unvegetated Gravel Bar: Alyeska will drive and operate bulldozers, excavators, and other heavy equipment only on unvegetated gravel bars.
• Removal of Isolation Berm and Regrading After Mining: Alyeska will grade the site level, contour the site to minimize water ponding, and slope it towards the downstream end at the end of the mining season.
• Minimal Stockpiles: Alyeska will remove the gravel and take it off site instead of stockpiling. All temporary stockpiles will be removed less than 5 days after completion of active mining operations.
• No Pumping Water from Site: Alyeska will not need to do any dewatering since the gravel will be mined above the level of the water table. Any water (such as precipitation) will rapidly percolate into the permeable sandy gravel river bar material.
• Sedimentation Control Measures: Alyeska will install specific BMPs (as dictated by site conditions) to minimize sediment from leaving the site, including silt fences and wattles.
• Water Diversion: Alyeska will install specific BMPs (as dictated by site conditions) to route water around the site such as temporary culverts and low water crossings.

  Additional BMPs for River Structures:

• Limit permanent fill and disturbance below ordinary high water to the minimum necessary for stabilization and infrastructure protection.
• Use stable, clean materials appropriately sized for anticipated velocity, ice, bed load, and scour conditions.
• Retain existing riparian and floodplain vegetation wherever practicable and stabilize disturbed areas promptly.
• Use temporary structures, mats, fills, and access features only as needed; remove them and restore affected areas after construction.
• Photograph and survey pre-work and as-built conditions to demonstrate the maintenance footprint and final configuration.
• Use existing access routes and previously disturbed areas where practicable.
• Limit construction crossings to designated locations and minimize the number, width, and duration of crossings.
• Minimize temporary fill in waters and wetlands; clearly stake approved limits of disturbance.
• Maintain drainage and aquatic connectivity through temporary access features.
• Remove temporary fills and restore channel, bar, bank, and floodplain contours.
• Minimize side casting or loss of fill outside the approved construction footprint.
• Account for all permanent and temporary fill quantities and locations in project drawings and permit documentation.
  1. Minimization: The applicant states that Alyeska would revegetate or stabilize vegetation after the project no later than next summer.
  2. Mitigation: The applicant has provided the following explanation why compensatory mitigation should not be required: Alyeska is both avoiding wetlands and minimizing any direct impacts.

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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