Norfolk Harbor Navigation Operations and Maintenance Project, Thimble Shoal Channel – West – Proposed dredged material Transport, and Placement at the Dam Neck Ocean Disposal Site.

U.S. ARMY CORPS OF ENGINEERS NORFOLK DISTRICT
Published Aug. 7, 2023
Expiration date: 9/1/2023

August 7, 2023
CENAO-WR-OT                                                                                       

FEDERAL PUBLIC NOTICE

SUBJECT:  Norfolk Harbor Federal Navigation Project, Thimble Shoal Channel– West – Proposed Dredged Material Transport and Placement at the Dam Neck Ocean Disposal Site

Pursuant to Section 103 of the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972 and USACE policy 33 Code of Federal Regulations (CFR) 337.1, this Public Notice serves as the U.S. Army Corps of Engineers, Norfolk District (Corps) notification relating to proposed transport for the purpose of disposal of suitable dredged material from the Norfolk Harbor Federal Navigation Project, Thimble Shoal Channel – West (TSC-W) at the Dam Neck Ocean Disposal Site (DNODS). The DNODS was designated by the U.S. Environmental Protection Agency (USEPA) pursuant to Section 102(c) of MPRSA for the ocean placement of suitable dredged material. The final rule was promulgated by EPA on March 31, 1988 (FR. Vol. 53 No. 62), effective March 31, 1988.  The dredging, transport, and placement at the Norfolk Ocean Disposal Site (NODS) will be an alternate placement site for suitable dredged material if needed to maintain navigation or if the DNODS is unavailable for placement of dredged material. The NODS was designated by the USEPA pursuant to Section 102(c) of MPRSA for the ocean placement of suitable dredged material. The final rule was promulgated by USEPA on July 2, 1993 (FR. Vol. 58 No. 126), effective July 2, 1993. Dredged material proposed for transport for the purpose of discharge in ocean waters must be evaluated by the U.S. Army Corps of Engineers in accordance with part 227 of MPRSA, Section 103 and processed in accordance with 33 CFR 324. The use of DNODS and/or NODS is contingent upon USEPA, Region 3 independent review and concurrence that the dredged material meets MPRSA criteria (40 CFR 227).

ACTIVITY:  Approximately 6.4 million cubic yards (MCY) of maintenance and new work dredged material from the Norfolk Harbor Federal Navigation Project, TSC-W was evaluated to determine compliance with the criteria in Part 227 of MPRSA, Section 103.  The dredged material from TSC-W is proposed for placement at the DNODS. Placement at the NODS will be an alternative placement site for suitable dredged material if needed to maintain navigation or if the DNODS is unavailable for placement of dredged material. The anticipated duration to remove shoaled sediment is expected to occur over a period of three years.  

LOCATION:  The TSC-W is located in the lower Chesapeake Bay, approximately 11 statute miles long and varies between 1,000 and 1,300 feet wide, extending from the -56 foot MLLW contour in Hampton Roads and east to the Chesapeake Bay Bridge Tunnel.

The DNODS boundary coordinates are as follows [40 Code of Federal Regulations (CFR) 288.5]:

Latitude               Longitude

36º 51’ 24.1” N      75º 54’ 41.4” W

36º 51’ 24.1” N      75º 53’ 02.9” W

36º 46’ 27.4” N      75º 51’ 39.2” W

36º 46’ 27.5” N      75º 54’ 19.0” W

36º 50’ 05.0” N      75º 54’ 19.0” W

The DNODS has an area of approximately 9 square nautical miles located in federal waters due east of the Dam Neck/Virginia Beach section of the Virginia coast and approximately 7 nautical miles south and east of the Chesapeake Bay. Water depth within the DNODS averages approximately 40 feet. The DNODS is divided into seven placement cells; cells 2, 5, 6, and 7 are designated for mixed and fine-grained materials and cells 1, 3, and 4 are reserved for sandy material. The site was designated by USEPA for suitable dredged material from three federal navigation channels: the Atlantic Ocean Channel, the Cape Henry Channel, and the Thimble Shoals Channel.

The DNODS has been in use since 1967 when the Corps initially deepened the Thimble Shoal Channel to 45 feet. Since that time, all new work and maintenance dredged material from Cape Henry Channel and Thimble Shoal Channel have been deposited at the DNODS. These deposits included a variety of naturally occurring marine sediments, ranging from silts and clays to fine, medium, and coarse sands. The Cape Henry Channel and Thimble Shoals Channel are maintenance dredged approximately every 2 to 3 years, and the DNODS is utilized for placement of suitable dredged material. The Norfolk Harbor Navigation Improvements Project involves the deepening and widening of channel segments. These new work channel elements have commenced construction and include the following channel segments: TSC-W between Hampton Roads and the Chesapeake Bay Bridge Tunnel (CBBT). This channel segment was dredged during the period of  June 15, 2019 through January 22, 2023 removing approximately 6,723,751 cubic yards (CY) and the dredged material placed at DNODS. The Thimble Shoal Channel – East and Meeting Area #2 project element is located between the CBBT and the mouth of the Chesapeake Bay. This channel segment was dredged during the period April 28, 2022 through present day removing approximately 2,705,169 CY to date and dredged material placed at DNODS. Thimble Shoals Channel – Meeting Area #1 is a widening of the channel located between Hampton Roads and the CBBT. This channel segment was dredged during the period March 29, 2023 through present day removing approximately 2,320,919 CY to date and dredged material placed at DNODS. There have been no documented effects from the authorized discharges that have been made in the placement area.

The NODS is located in the Atlantic Ocean approximately 17 statute miles east of Cape Henry. The center point coordinate of the NODS is latitude 36°59’00” North and longitude 75°39’00” West. The site is circular with a radius of 4 nautical miles and has an area of approximately 50 square nautical miles. Water depth within the NODS ranges from -42 to -85 ft MLLW. The site has unlimited capacity and is designated to provide capacity for long-term management of dredged material from the lower Chesapeake Bay and suitable materials from Norfolk Harbor (USEPA 1992). Any dredged material that passes ocean placement criteria may be placed at the NODS.

Prior to 2008, the NODS was solely used by the U.S. Navy. In August 1993, approximately 51,000 CY of dredged material from the Naval Supply Center Cheatham Annex and 475,000 CY of dredged material from the Naval Weapons Station Yorktown were placed at the site. Since 2010, other projects that have been placed at the NODS include the VDOT – Midtown Tunnel (1,121,642 CY placed October 2013 to October 2014), Joint Base Langley Eustis (JBLE) – Skiffes Creek Channel (128,244 CY placed November 2014 to December 2014), JBLE – Fuel Pier Basin (57,122 CY placed February 2019 to July 2019), the JBLE – Back River Channel (125,723 CY placed February 2019 to July 2019), and Norfolk Harbor Channels 50-ft Maintenance (1,054,084 CY was placed November 29, 2022 to April 27, 2023). Other projects that have been previously evaluated or permitted for placement at the NODS include CIEE (24.5 MCY), Yorktown Naval Weapons Station (65,000 CY), Chesapeake Bay Bridge Tunnel – Parallel Thimble Shoals Tunnel Project (1.7 MCY), Cheatham Annex CAD-A Pier (88,000 CY), Naval Weapons Stations Yorktown R3 Pier (110,000 CY), and Portsmouth Marine Terminal (216,737 CY). There have been no documented effects from the authorized discharges that have been made in the placement area.

DREDGED MATERIAL CHARACTERITICS AND COMPOSITION: Sediments proposed for dredging consist of maintenance and new work dredged material from the TSC-W. Grain size of the dredged material in the channel transitions from west to east with primarily fine-grained (69-80% silt/clay) sediments in the western portion of the channel, transitioning to a mix of fines grained sediments and sand (38-48% sand, 52-59% silt/clay), followed by transition to predominant sands (46-69% sand) in the eastern reach of the channel proximate to the CBBT. The dredged material proposed for placement at DNODS does not meet the testing exclusionary criteria set forth under 40 CFR 227.13(b). Dredged material testing of the TSC-W detected the presence of metals and dioxin/furan congeners in the bulk sediments from TSC-W, and therefore further testing of the liquid, suspended particulate and solid phases was completed.

Dredged material from TSC-W was tested for liquid phase (e.g. numeric water quality criteria, liquid and suspended particulate phase (e.g. water column toxicity), and solid phase (e.g., benthic toxicity and benthic bioaccumulation) using criteria and procedures developed by the Administrator of the USEPA in accordance with 40 CFR 220-228. Evaluation of the liquid phase has determined the material from TSC-W complies with the Limiting Permissible Concentration (LPC) at the DNODS as well as the NODS and is in compliance with 40 CFR 227.6(c)(1) and 227.27(a)(1). Evaluation of the liquid and suspended particulate phase has determined the material from TSC-W complies with the LPC at the DNODS as well as the NODS and is in compliance with 40 CFR 227.6(c)(2) and 227.27(b). Evaluation of the benthic toxicity solid phase has determined the material from TSC-W complies with the LPC and is in compliance with 40 CFR 227.13(c)(3), 227.6(c)(3) and 227.27(b) for placement at the DNODS and the NODS. The dredged material from TSC-W meets the LPC for benthic bioaccumulation and complies with the benthic criteria of 40 CFR Part 227.13 (c) (3) for placement at DNODS and NODS. The dredged material as described from the Norfolk Harbor Navigation Operations and Maintenance Project, Thimble Shoal Channel – West meets the MPRSA criteria (40 CFR 227).

ENVIRONMENTAL DOCUMENTATION:  The environmental impacts of the Norfolk Harbor Navigation Operations and Maintenance project have been evaluated in National Environmental Policy Act and regulatory documents including: (1) the Final General Reevaluation Report and Final Environmental Assessment/Finding of No Significant Impact dated June 2018; and (2) the Finding of No Significant Impact was executed on 16 October 2018.

COMMENT PERIOD:  Comments on this project should be in writing and can be sent by either email to JavierAnn.F.Wright@usace.army.mil, or by regular mail, addressed to the Norfolk District, Corps of Engineers (ATTN: Javier Wright, CENAO-WR-O), 803 Front Street, Norfolk, Virginia  23510-1011, and should be received by the close of business on September 1, 2023.

PRIVACY & CONFIDENTIALITY:  Comments and information, including the identity of the submitter, submitted in response to this Public Notice may be disclosed, reproduced, and distributed at the discretion of the U.S. Army Corps of Engineers. Information that is submitted in connection with this Public Notice cannot be maintained as confidential by the U.S. Army Corps of Engineers. Submissions should not include any information that the submitter seeks to preserve as confidential.

If you have any questions about this project, contact Javier Wright at 757-201-7890 or by email at JavierAnn.F.Wright@usace.army.mil.

Attachment: TSC – W - Overview Map