Notice of Application for State Water Quality Certification, Tanaku Lodge Dredging

Any applicant for a federal license or permit to conduct an activity that might result in a discharge into navigable waters, in accordance with Section 401 of the Clean Water Act (CWA) of 1977 (PL95-217), also must apply for and obtain certification from the Alaska Department of Environmental Conservation that the discharge will comply with the CWA, the Alaska Water Quality Standards, and other applicable State laws. 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 for the discharge of dredged and/or fill materials into waters of the United States (WOUS), 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

target="_blank">https://dec.alaska.gov/water/wastewater/. To comment on the project or request for a public hearing with respect to water quality, submit comments electronically via the DEC public notice site at https://water.alaskadec.commentinput.com/?id=KNDSY on or before the public notice expiration date listed above. Applicant: Tanaku Lodge, James Benton, PO Box 74 Elfin Cove, AK 99825; 541-325-1530; jim@tanaku.com. Agent: PND Engineers, Inc., Dick Somerville, 9360 Glacier Highway Suite 100, Juneau, AK 99801; 907-586-2093; dsomerville@pndengineers.com. Project Name: Tanaku Lodge Dredging Location: The proposed activity is located within Section 25, T. 42s, R. 55e; Copper River Meridian; in Hoonah Angoon Census Area, Alaska. Project Site Latitude: 58.19386, Longitude -136.34936, with the potential to discharge temporary turbidity from dredging activity at 58.19386, -136.34936 and disposal of dredged material at an offshore disposal site located at 58.15160, -136.34070. Purpose: The purpose of the project is to dredge to -8’ MLLW to provide safe and reliable navigation and moorage of small recreational vessels at the Tanaku Lodge. The seafloor in the vicinity of the lodge has gradually risen over the years, likely due to glacial isostatic rebound, creating a navigational hazard. Vessels moored to the float contact the seafloor on low tides and are often stranded at the moorage float without adequate water depth to reach the federal navigation channel. Project Description: The applicant is proposing to utilize a mechanical clamshell to dredge approximately 420 cubic yards of marine sediment from the seafloor to a depth of minus 8-feet mean low low water (MLLW). The applicant is proposing in-water disposal of the dredged material at the Port Althorp Dredge Disposal Area designated by the Civil Branch of U.S. Army Corps of Engineers (Corps) as part of the current federal dredging activity for the Elfin Cove Navigation Channels. The proposed dredging would take place at the same time as a planned Civil Works project. Due to steep topography, thick forest, and lack of infrastructure, upland disposal is not a valid option for this project. Due to strong currents and coarse dredge materials, the potential for contamination to be present is low. Recent USACE samples describe the dredge materials in this vicinity as poorly graded sand with silt and gravel. The proportion of coarse grain materials ranged from 90-99% in the sediments. The Elfin Cove fuel dock is over 500 feet away from the dredge site and any fuel related contaminants are unlikely to be absorbed by coarse grain sediments, especially in this high energy hydrodynamic environment. The USACE reports powerful tidal currents within the Elfin Cove navigational channels with an estimated average theoretical flow rate of 30,500 cubic feet per minute using a constant rate between high and low tide. The USACE studied several potential offshore disposal sites as part of its Environmental Assessment and Finding of No Significant Impact for Maintenance Dredging Elfin Cove Navigational Channels dated at May 2022. A preferred disposal site was selected based on the low catch rate of fish, crabs, and other invertebrates by USACE biologists during several seasonal sampling trips. The proposed disposal site is approximately 4 acres in size and is located at a water depth of approximately 540 feet. Additional Information: The Corps collected surface sediment samples for geotechnical analysis in May of 2019, and the lab results describe the material as poorly graded sand with silt and gravel. The proportion of coarse grain material (sand and/or gravel) ranges from 95% in the outer channel to 90.4% in the outer part of the inner channel, to 98.9% in the inner channel. The percentage of the material is very high sand content, such that it would not be a carrier of contaminants. 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: a. The dredging contractor will prepare an Oil Spill Prevention and Control Plan. Reasonable precautions and controls will be used to prevent incidental and accidental discharge of petroleum products or other hazardous substances. Fuel storage and handling activities for equipment will be sited and conducted to prevent petroleum contamination of the ground, surface runoff, or water bodies. Equipment will be inspected daily for leaks. In case of leaks, equipment will not be used and pulled from service until the leak is repaired. During construction, spill response equipment and supplies such as sorbent pads shall be available and used immediately to contain and cleanup oil, fuel, hydraulic fluid, antifreeze, or other pollutant spills. Any spill amount will be reported in accordance with Discharge Notification and Reporting Requirements (AS 46.03.755 and 18 AAC 75 Article 3). b. Timing of Construction Activities: There are no formal environmental requirements that dictate timing windows for this project. However, dredging in Elfin Cove, particularly the Inner Channel, will pose a major limitation to marine vessel traffic during the approximately two-day period of construction. Travel to or from the inner harbor area will be limited when dredging at Tanaku Lodge. Safe passage will be accommodated during the dredging operations with sufficient advance coordination with the construction contractor. To minimize the impacts of dredging on vessels at Elfin Cove, dredging would take place during an approximately two-day period between March 15, 2023, and April 15, 2023. This timing window avoids all the summer charter vessel operations and most of the commercial fishing activity. Access to the fuel dock and float plane dock will remain available during dredging so vessels can have access to fuel and temporary safe moorage. Access by float planes will not be impeded by any dredging activities. Access to both the fuel dock and float plane dock are available through a separate channel. c. Minimization of Impacts to Protected Species: The proposed project minimizes potential impacts to protected species due to the timing of construction activities and the confined, shallow water nature of the dredged channels. Construction between March 15, 2023, and April 15, 2023, would likely result in far fewer marine mammals both in the construction area and enroute to the disposal area. To minimize the potential harm to marine mammals, the applicant will have a contracted observer on site during construction to temporarily pause dredging operations for marine mammals within 50 meters (approximately 164 feet) of active dredging. Vessels traveling to and from the disposal area will avoid any aggregations of marine mammals within the limits of safe navigation by altering speed, course, or both. After reviewing the application, the Department may certify there is reasonable assurance the activity, and any discharge that might result, will comply with the CWA, the Alaska Water Quality Standards, and other applicable State laws. The Department also may deny or waive certification. The permit application and associated documents are available for review. For inquires or to request copies of the documents, contact dec-401cert@alaska.gov, or call 907-269-6285. Disability Reasonable Accommodation NoticeThe 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 Claire Fishwick at 907-465-5871 or TDD Relay Service 1-800-770-8973/TTY or dial 711 prior to the expiration date of this public notice to ensure that any necessary accommodations can be provided.