Sediment Report 3.pdf

DRAFT

MARINE PROTECTION, RESEARCH, AND SANCTUARIES ACT (MPRSA)

SECTION 103 EVALUATION

CHEATHAM ANNEX

CAD-A PIER

YORK RIVER, VIRGINIA

April 2022

Prepared for:

U.S. Environmental Protection Agency, Region 3 1650 Arch Street Philadelphia, Pennsylvania 19103

Prepared by:

EA Engineering, Science, and Technology, Inc., PBC 225 Schilling Circle, Suite 400 Hunt Valley, Maryland 21031

Submitted by:

Department of the Navy Naval Facilities Engineering Systems Command (NAVFAC) Mid-Atlantic Division (MIDLANT) Norfolk, Virginia

Department of the Army U.S. Army Corps of Engineers Norfolk District 803 Front Street Norfolk, Virginia 23510

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MARINE PROTECTION, RESEARCH, AND SANCTUARIES ACT (MPRSA)

SECTION 103 EVALUATION

CHEATHAM ANNEX,

YORK RIVER, VIRGINIA

April 2022

1. DREDGING AND PLACEMENT PROJECT INFORMATION.

The subject of this evaluation is the maintenance dredging of Cheatham Annex (CAX) CAD-A Pier, and the subsequent placement of dredged material in the Norfolk Ocean Disposal Site (NODS) (Figures 1 and 2). Navigational access to the CAD-A Pier at Cheatham Annex in Yorktown, Virginia by U.S. Navy vessels is essential for operation of a mission-ready force.

Appropriate berthing for vessels allows for safe access to ships for personnel and for loading supplies as well as for preventing damage to ship hulls and water intakes. The NODS was identified as the location for the placement of material dredged from CAX because: (1) the NODS is designated to provide capacity for long-term management of dredged material from the lower Chesapeake Bay region, and (2) it has the capacity to accept material.

a. Dredging Location. The proposed CAX CAD-A Pier project is located along the southern bank of the York River on the site of Cheatham Annex (Figure 1) near Williamsburg, Virginia. The maintenance dredging footprint at the CAX CAD-A Pier is approximately 8.68 acres and is divided into five dredging areas – B, C1, C2, D, and E. The maintained depth in Areas B, C1, and C2 is -20 feet (ft) mean lower low water (MLLW). The maintained depths in Areas D and E are -35 ft and -32 ft MLLW, respectively. Two dredging units were evaluated for the CAX CAD-A Pier:

sediments composited from Areas B, C1, and C2 (B/C1/C2) and sediments composited from Areas D and E (D/E).

b. Core Borings. No core borings from the CAX were collected for submittal with this Section 103 Evaluation. The CAX project represents maintenance dredging only.

c. Volume of Material to be Dredged. For this evaluation, a maximum dredging depth of -22 ft MLLW (Areas B, C1, and C2), -37 ft MLLW (Area D), and -34 ft MLLW (Area E) is requested for MPRSA Section 103 concurrence, which consists of the maintained depths of -20 ft, -35 ft, and 32-ft MLLW, respectively, plus an additional 2 ft comprised of overdepth. Up to 88,000 cubic yards (cy) of dredged material may be removed from the CAX in the next 3 years to fully maintain the project depth required for safe U.S. Navy vessel operations.

Figure 1. Vicinity Map: Cheatham Annex CAD-A Pier, York River, Virginia

Figure 2. Location Map: Willoughby Bank Reference Site, Chesapeake Bay Control Site, and Norfolk Ocean Disposal Site.

Source: EA Engineering, Science, and Technology, Inc., PBC (EA) 2022.

Dredging Unit

Dredging Area

Maintenance Depth (ft MLLW)

Overdepth (ft)

Total Dredging Depth

(ft MLLW) Maximum Sediment

Volume (cy)(a)

B/C1/C2 B -20 2 -22 2,000 C1 -20 2 -22 6,000 C2 -20 2 -22 27,000

D/E D -35 2 -37 41,000 E -32 2 -34 12,000

(a) Based on siltation projected to November 2022 for contract depth + 2 ft overdepth

d. Grain Size of Dredged Material. Sediments collected from the CAX CAD-A Pier in December 2021 were comprised primarily of fine-grained materials and consisted of 95.5 and 95.8 percent silt+clay in the two composite dredging unit samples (Table 1 and Figure 3). The physical characteristics of sediments from the CAX CAD-A Pier were most similar to the physical characteristics of sediments in the subsurface sample from Willoughby Bank Reference Site (WBREF-SUB) which were comprised of 79.8 percent silt+clay.

e. Bathymetric Information. The most recent bathymetric surveys of CAX were conducted in March 2021. The bathymetry data for the area to be dredged are included in Attachment I.

f. Description of the Disposal Area. The NODS (Figure 2) is located in the Atlantic Ocean approximately 17 statute miles east of Cape Henry Channel and is approximately 50 square nautical miles in size (40 Code of Federal Regulations [CFR] Part 228). The site is circular with a radius of 4 nautical miles and a water depth that ranges from 43 to 85 ft (U.S. Army Corps of Engineers [USACE] Norfolk District and Virginia Port Authority 2018). The Chesapeake Light Tower is located approximately 2 statute miles south/southeast of the site.

The center point coordinate of the NODS is (40 CFR Part 228):

Latitude: 36º 59’ 00” N Longitude: 75º 39’ 00” W

The NODS has unlimited capacity and is designated for use as an alternate site for the lower Chesapeake Bay channels as well as a placement location for suitable materials from the Norfolk Harbor Channels within the Port of Hampton Roads (CENAO 1994 cited by USACE Baltimore District 2005). The Final Environmental Impact Statement for the designation of the Norfolk Ocean Disposal Site (U.S. Environmental Protection Agency [USEPA] Region 3 1992) states that the site was intended to provide capacity for long-term management of dredged material from the Lower Chesapeake Bay and suitable material from Norfolk Harbor. However, the Final Environmental Impact Statement also states that the site could be used for placement of material from other dredging projects that meet the requirements of Section 103 of the MPRSA. The designation of the site in 40 CFR Part 228.15 indicates the “site shall be limited to suitable dredged material which passed the criteria for ocean dumping.”

Figure 3. Grain Size Distribution in the Cheatham Annex CAD-A Pier and Willoughby Bank Reference Site (2021).

Source: EA 2022

WBREF-SURF-SED WBREF-SUB-SED CAX21-B/C1/C2-SED CAX21-D/E-SED

SAND SILT CLAY

Prior to 2008, the only use of the NODS was 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. Dredged material from both projects was primarily comprised of silts and clays. Since 2010, other projects that have been placed at the NODS, are currently being placed at the NODS, or are approved for future placement at the NODS include: The Virginia Department of Transportation 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), and JBLE-Back River Channel (125,723 cy placed February 2019 to July 2019). Other projects that have been previously permitted for use of the NODS include: the Craney Island Eastward Expansion Project, and the Chesapeake Bay Bridge Tunnel – Parallel Thimble Shoal Tunnel. It should be noted that although these other projects were initially permitted for use of the NODS, the USEPA concurrence for each of these projects has expired. The NODS serves as a backup placement option for segments of the Norfolk Harbor Channel Deepening, including: Norfolk Harbor Channels-Sewells Point to Lamberts Bend reach, Thimble Shoal Channel-East, Meeting Area 1, Meeting Area 2, and Atlantic Ocean Channel. The NODS also serves as a backup placement option for the maintenance materials from the Upper Chesapeake Bay approach channels to the Port of Baltimore that pass the ocean placement criteria.

A Site Monitoring and Management Plan (SMMP) for the NODS became effective in 1998, was renewed in February 2009, and was most recently renewed again in February 2019. The goal of the SMMP is to protect the marine environment and document the dredged material placement activities at the NODS (USACE Norfolk District/USEPA Region 3 2019). The objective of the SMMP is to provide guidelines in making management decisions necessary to fulfill the mandated responsibilities to protect the marine environment. The specific management objectives of the NODS include: (1) protection of the marine environment, living resources, and human health and welfare; (2) documentation of disposal activities at the NODS and provision of information that is useful in managing the dredged material placement activities; and (3) beneficial use of dredged material whenever practical (USACE Norfolk District/USEPA Region 3 2019).

g. Expected Start, Duration, and End of Dredging. Maintenance dredging of the CAX CAD-A Pier is expected to start in July 2022 and be completed no later than 15 February 2023.

h. Location of Placement within the NODS. The dredged material will be mechanically excavated, transported to the NODS using bottom dump scows, and placed in a designated placement zone within the NODS where it will be evenly distributed. The proposed placement zone within the NODS for the Yorktown Pier R3 material was determined based on consultation with USEPA Region 3 and USACE Norfolk District (Figure 4). Progress surveys of portions of the active zone during placement periods will be utilized, if warranted, to ensure proper placement of materials.

Placement of dredged material from the NWS Yorktown R3 Pier was modeled using the USACE Short-Term Fate of Dredged Material Disposal in Open Water (STFATE) model, which simulates the movement of the disposed material as it falls through a water column, spreads over the bottom, and is transported as suspended sediment by the ambient current. Multiple discharge scenarios were modeled to determine the dilution achieved and distance the elutriate plume moved within

Figure 4. Designated Cheatham Annex Dredged Material Placement Zone in the NODS.

the 4-hour allowable mixing period following discharge and to determine the maximum discrete discharge volume per placement event that would comply with the limiting permissible concentration (LPC) for water quality criteria (WQC) and water column toxicity.

i. Compliance with NODS Site Designation Conditions. USEPA and USACE manage the NODS through a joint SMMP. Use of the site for dredged material placement will comply with site requirements. Naval Facilities Engineering Systems Command (NAVFAC) or its contractors will perform after-placement bathymetric surveys of the designated placement area within the NODS. These surveys may be performed periodically to ensure compliance with contract requirements and the SMMP (USACE Norfolk District/USEPA Region 3 2019) for the NODS.

Other surveys may be performed as necessary.

2. EXCLUSIONARY CRITERIA

The exclusionary criteria (40 CFR Part 227.13) are used to determine if material is acceptable for ocean placement without further testing. If the material meets any of the following three criteria, it is considered environmentally acceptable for ocean placement without further Tier II (chemical) or Tier III (ecotoxicological) testing:

1. The dredged material is comprised predominately of sand, gravel, rock, or any other naturally occurring bottom material with particle sizes larger than silt, and the material is found in areas of high current or wave energy.

2. Dredged material is for beach nourishment or restoration and is comprised predominately of sand, gravel, or shell with particle sizes comparable with material on the receiving beaches.

3. The material proposed for placement is substantially the same as the substrate at the proposed placement site, and the site from which the material proposed for placement is to be taken is far removed from known sources of pollution so as to provide reasonable assurance that such material has not been contaminated by such pollution.

Based on the results of previous testing (2011 and 2017/2018) and results of grain size analyses conducted in 2021, the maintenance material from the CAX does not meet the exclusionary criteria (40 CFR Part 227.13).

3. NEED FOR TESTING FOR OCEAN PLACEMENT

a. Requirement for Testing. The CAX CAD-A Pier maintenance sediments are comprised of silts and clays and do not meet the exclusionary criteria set forth under 40 CFR 227.13(b). Therefore, tiered testing in accordance with 40 CFR 227.32, and following protocols in the Ocean Testing Manual (USEPA/USACE 1991), the Mid-Atlantic Regional Implementation Manual (USEPA Region 3 2000), and the Southeast Regional Implementation Manual (USEPA/USACE 2008), was conducted to determine if the proposed dredged material from the CAX CAD-A Pier meets the LPC for ocean placement at the NODS.

b. Dates of Previous Dredging. The CAX CAD-A Pier was last dredged in December 2018 through February 2019 removing approximately 40,540 cy of material. The material was placed upland at Port Tobacco at Weanack. Material from the prior maintenance dredging cycle (2013- 2014) was placed at the NODS.

c. Results of Previous Testing. Four previous dredged material evaluations (2001, 2004, 2011 and 2017/2018) included Tier II and Tier III evaluations of physical, chemical, and ecotoxicological properties of sediment and elutriates (Geo-Marine 2004; EA 2012; and CH2M 2018). The CAX CAD-A Pier project area was evaluated in 1992 as part of the Long-Term Management Strategy dredged material disposal study (Palermo et al. 1992). The site was resampled in 2001, and again in 2004, by Geo-Marine, Inc. using the Tier III guidelines specified by USEPA’s Ocean Testing Manual USEPA/USACE 1991).

In 2011, five locations from the CAX CAD-A Pier were sampled to create two composites that were compared to the Willoughby Bank Reference site (EA 2012). Results of the Tier II and Tier III testing indicated that the materials complied with the LPC for WQC, water column toxicity, benthic toxicity, and benthic bioaccumulation. Ammonia was identified as a probable toxicant in the water column bioassays performed with Mytilus galloprovincialis. The USEPA MPRSA Section 103 concurrence issued for this testing expired on 14 February 2016.

In 2017/2018, five locations from CAX were sampled to create two composites that were compared to the Willoughby Bank Reference Site (CH2M 2018). An ocean placement concurrence was not issued due to mortality of clams during the Tier III bioaccumulation exposures and due to concentrations of several polycyclic aromatic hydrocarbons (PAHs) in clam tissue that statistically exceeded both the reference tissue concentrations and background tissue concentrations for the South Atlantic Bight. Ammonia was identified as a probable toxicant in the water column bioassays performed with M. galloprovincialis and as a toxicant in the 28-day bioaccumulation exposures. The material for the 2018-2019 maintenance cycle (approximately 40,540 cy) was placed upland at Port Tobacco at Weanack.

d. Locations for Previous Testing. Sampling locations for the 2011(EA 2012) and 2017/2018 testing (CH2M 2018) are presented on Figure 5. The sampling locations for the 2004 testing can be found in the Geo-Marine report (2004).

e. Recent Events Influencing Testing Results. There are no known events to have occurred in the project vicinity either immediately before or following the December 2021 CAX sampling event that would be expected to influence the sediment chemistry or bioassay results presented for the proposed maintenance sediments in this evaluation.

4. WATER COLUMN DETERMINATIONS

In December 2021, eight discrete locations in the proposed CAX CAD-A Pier dredging area were sampled. The eight discrete locations were used to create two dredging unit composites (each composite was composed of sediment from four discrete locations) which were submitted for further tiered testing following protocols in the Ocean Testing Manual (USEPA/USACE 1991), the Mid-Atlantic Regional Implementation Manual (USEPA Region 3 2000), and the Southeast

Figure 5. Previous Sediment Sampling Locations for Cheatham Annex CAD-A Pier, 2011 and 2017.

Sources: EA 2012 and CH2M 2018

Regional Implementation Manual (USEPA/USACE 2008). Results of the studies and a description of the sampling and testing methodologies are detailed in the Sampling and Analysis Plan (SAP) (EA 2021) and in Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022).

Sediment cores were collected with a vibracore from eight locations at the CAX CAD-A Pier (CAX21-B-1, CAX21-C1-1, CAX21-C2-1, CAX21-C2-2, CAX21-D-1, CAX21-D-2, CAX21-D-3, and CAX21-E-1) (Figure 6), and two composites were created, each consisting of sediment from four adjacent locations (CAX21-B/C1/C2 and CAX21-D/E). These composites were submitted for physical and chemical analyses and used for standard elutriate preparation and ecotoxicological testing. Water targeted for chemical analysis and elutriate preparation was collected from one location within the CAX (CAX21-C1-1). Receiving water was collected from the NODS. Reference sediment (surface and subsurface) was collected from the Willoughby Bank Reference Site. Control sediment for amphipod bioassays was collected from the USEPA-designated control site in the lower Chesapeake Bay (Figure 2).

a. Sediment Testing. Target analytes for the 2021/2022 sediment testing were consistent with the constituents tested in the programs conducted for CAX CAD-A in 2011 and 2017/2018 (EA 2012 and CH2M 2018, respectively), and were based on consultation with USACE Norfolk District and USEPA Region 3. Results of the physical and chemical testing of the bulk sediment from NWS Yorktown R3 Pier and comparisons to marine sediment quality guidelines (SQGs) (MacDonald et al. 1996; Canadian Council of Ministers of the Environment 2001) are summarized in Tables 1 through 9. Two bulk sediment composites and the reference sediments were tested for the following target constituents:

Acid volatile sulfide (sediment only) Ammonia (NH3-N) Butyltins Chlorinated pesticides Cyanide Dioxins and furan congeners Metals Mercury Nitrate Nitrite Organophosphorus pesticides Polychlorinated biphenyl (PCB) congeners PAHs Semivolatile organic compounds (SVOCs) Simultaneously extracted metals (sediment only) Total Kjeldahl nitrogen Total sulfide Total organic carbon Total phosphorus

Figure 6. Cheatham Annex CAD-A Pier Sediment Sampling Locations (December 2021).

Source: EA 2022

In addition, the following physical analyses were conducted for the bulk sediments:

Grain size determination Atterberg limits Total solids Bulk density Specific gravity

Detailed results of the bulk sediment testing are provided in Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022).

The results of the grain size analysis indicated that the CAX CAD-A Pier sediment composites were primarily comprised of fine-grained materials, ranging from 95.5 to 95.8 percent silt/clay (Section 1(d), Table 1, and Figure 3). Results for metals and organic constituents are provided in Tables 2 to 9. Metals (Table 3), PAHs (Table 5), dioxin/furan congeners (Table 7), and SVOCs (Table 8) were the only analyte groups with constituents detected above the laboratory reporting limit (RL) in the sediments.

Comparisons of chemical concentrations in the CAX sediment to marine SQGs indicated that one of the detected metals (arsenic) exceeded the threshold effects level (TEL). Arsenic exceeded the TEL (7.24 milligrams per kilogram) by a factor of 1.09 and 1.04. Total PCBs (non-detect [ND] = RL) exceeded the TEL (21.6 micrograms per kilogram) but the exceedances were based on the summation of laboratory RLs. Sixteen individual PAHs were detected in the sediments from the CAX composite samples; four PAHs (acenaphthene, acenaphthylene, fluorene, and phenanthrene) were detected at a concentration that exceeded their respective TELs. Total low molecular weight PAHs (ND=RL) exceeded the TEL (312 micrograms per kilogram) in CAX21-D/E by a factor of

1.16. Dioxin toxicity equivalency quotients (ND=RL) in the CAX composite samples exceeded the interim SQG (0.85 nanogram per kilogram) by factors ranging from 23.1 to 23.8. One SVOC (bis[2-ethylhexyl] phthalate) was detected in both composite samples at concentrations estimated below the laboratory RL and exceeded the TEL (182 micrograms per kilogram) by factors of 3.30 and 3.52. Phenol was also detected in both of the CAX CAD-A Pier composites. Chlorinated pesticides were not detected above the laboratory RL, and organophosphorus pesticides and butyltins were not detected in the CAX CAD-A Pier sediment composites.

b. Water Column Elutriate Testing. Six standard elutriates were prepared for the CAX using the two sediment composites and site water collected from one location (CAX21-C1-1). Receiving water was also collected within the boundaries of the NODS. Results of the elutriate, site water, and receiving water chemical analyses and comparisons to USEPA acute saltwater quality criteria for aquatic life (USEPA 2022) are summarized in Tables 10 to 17. Details of the elutriate analysis are provided in Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022).

Elutriate preparation water (dredging site water) chemistry results indicated that several chemical constituents were detected in the elutriate preparation water from the CAX. The majority of detected concentrations were low or estimated below the laboratory RL. Ammonia was the only detected constituent in the CAX elutriates that exceeded acute WQC. Ammonia exceeded the USEPA acute WQC (6.82 milligrams per liter) in the CAX elutriates by factors of 4.69 and 4.40 (Table 10). The laboratory RL for cyanide and toxaphene exceeded the USEPA acute saltwater WQC criterion by factors of 10 and 2.38, respectively, in the CAX elutriates. Although not detected in each of the standard elutriates, cyanide was conservatively used in the STFATE model as the constituent requiring the greatest dilution to achieve the WQC for the CAX CAD-A Pier elutriates.

To determine whether the sediments from the CAX CAD-A Pier meet the WQC LPC requirement, STFATE modeling was conducted. The LPC for WQC is the elutriate concentration which:

1) Does not exceed the WQC outside the site boundary during the first 4 hours, and

2) Does not exceed the WQC anywhere in the marine environment after 4 hours.

STFATE modeling was conducted to confirm that sufficient dilution would be achieved to meet the WQC LPC and to confirm that the elutriate plume would stay within the boundary of the NODS placement site within the 4-hour period required by the MPRSA. STFATE modeling was conducted using the specifications of the NODS (i.e., dimensions and water column properties), physical characteristics of the sediment collected from the CAX CAD-A Pier dredging area (i.e., grain size and specific gravity), and the concentrations of the chemical(s) in the elutriates that exceeded applicable WQC (Attachment II). The Tier II STFATE evaluations were conducted using an assumed background concentration of zero, mechanical dredging, and a 20,000-cy discrete discharge volume.

The model output indicated that cyanide required a dilution factor of 9 to meet the WQC LPC for placement at the NODS. Results of STFATE modeling indicated that a dilution of 9-fold would be achieved at a distance of 1,414 ft from the location of discharge. The model predicted that a dilution ranging from 126-fold to 127-fold would be achieved during the allowable 4-hour mixing period, and the elutriate would travel a maximum distance of 4,101 ft from the location of discharge during the 4-hour period. Therefore, based on the results of the STFATE modeling, the standard elutriates from the CAX CAD-A Pier meet the LPC for WQC for placement at the

NODS.

c. Water Column Bioassays. Three water column species, Mytilus galloprovincialis (blue mussel), Americamysis bahia (opossum shrimp), and Menidia beryllina (inland silverside), were exposed to elutriates created from the CAX sediments and the elutriate preparation water (site water), and to a laboratory control. The blue mussel tests measured developmental effects to embryos, and the opossum shrimp and inland silverside tests measured effects to organism survival. The test protocols are detailed in the SAP (EA 2021), EA Ecotoxicology Laboratory Quality Assurance and Standard Operating Procedures Manual (EA 2018), and Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022).

Mytilus galloprovincialis The 48-hour median effective concentration (EC50) values in the untreated elutriates from the CAX CAD-A Pier were 12.4 and 33.2 percent. Normal development in the 100 percent untreated elutriates was 0 percent for both elutriates, at least 10 percent less than and statistically different from the laboratory control. The ammonia concentrations measured in the two elutriates prior to test initiation ranged from 12.8 to 13.4 milligrams per liter NH3-N, which exceeded the 48-hour ammonia EC50 value of 1.8 milligrams per liter NH3-N obtained in the ammonia toxicity study with M. galloprovincialis. The laboratory controls had normal embryo development that ranged from 87 to 91 percent, and the site water sample CAX21-WAT had 87 percent normal embryo development (Table 18).

Americamysis bahia For each of the elutriates from the CAX CAD-A Pier, the 96-hour median lethal concentration (LC50) value was greater than 100 percent elutriate. Survival values in the 100 percent elutriates were each 100 percent and were not significantly different from the laboratory control, indicating that the elutriates were not acutely toxic to A. bahia. After 96 hours of exposure, survival values in the laboratory controls were each 100 percent (Table 18).

Menidia beryllina For each of the elutriates from the CAX CAD-A Pier, the 96-hour LC50 value was greater than 100 percent elutriate. Survival values in the 100 percent elutriates were each 100 percent and were not significantly different from the laboratory control, indicating that the elutriates were not acutely toxic to M. beryllina. After 96 hours of exposure, survival values in the laboratory controls were each 98 percent (Table 18).

STFATE Modeling and LPC Compliance STFATE modeling was conducted to determine if the results of the water column bioassays would meet the water column toxicity LPC for ocean placement. STFATE modeling was conducted assuming mechanical dredging and a maximum 20,000-cy discrete discharge volume. If the model indicated non-compliance with the LPC for a 20,000-cy discharge volume, multiple scenarios were modeled to determine the maximum discrete discharge volume that would comply with the LPC.

The input and output information for the STFATE modeling is provided in Attachment II.

The LPC for water column toxicity is the concentration that does not exceed 0.01 of the EC50/LC50 value within a 4-hour dilution period inside the boundary of the ocean placement site. If ammonia is a demonstrated toxicant, the LPC for water column toxicity is the concentration that does not exceed 0.05 of the EC50/LC50 value within a 4-hour dilution period inside the boundary of the ocean placement site.

In the water column, bioassays with A. bahia and M. beryllina had a LC50 values that were greater than 100 percent elutriate for each composite. Comparison of the untreated and ammonia-purged elutriate results for M. galloprovincialis indicated that ammonia was the main constituent in the CAX CAD-A Pier elutriates contributing to water column toxicity. Therefore, the LPC for the water column toxicity is the concentration that does not exceed 0.05 of the LC50/EC50 value within a 4-hour allowable mixing period inside the boundary of the placement site (USEPA/USACE 1991).

Normal embryo development for M. galloprovincialis in each of the untreated CAX CAD-A Pier elutriates was statistically different (lower) than the laboratory control. A dilution ranging from

59-fold to 160-fold is required to meet the LPC for these samples. Results of the STFATE modeling for CAX21-D/E indicated that a 20,000-cy discrete discharge volume would achieve a 59-fold dilution at a distance of approximately 3,111 ft from the point of discharge, a 126-fold dilution would be achieved during the allowable 4-hour mixing period, and the elutriate would travel a maximum distance of 4,101 ft from the point of discharge during the 4-hour period. Results of the STFATE modeling for CAX21-B/C1/C2 indicated that a 14,000-cy discrete discharge volume would achieve a dilution of 160-fold at a distance of approximately 4,101 ft from the point of discharge, a 165-fold dilution would be achieved during the allowable 4-hour mixing period, and the elutriate would travel a maximum distance of 4,101 ft from the point of discharge during the 4-hour period. Based on the results of the water column bioassays and STFATE modeling, the elutriates from the CAX CAD-A Pier meet the LPC for water column toxicity for placement at the NODS for a maximum discrete discharge volume of 14,000 cy.

5. BENTHIC DETERMINATIONS

a. Benthic Toxicity Evaluation. Whole sediment bioassays were conducted using two benthic species, Ampelisca abdita (marine/estuarine amphipod) and Leptocheirus plumulosus (estuarine amphipod). The tests were conducted as static, non-renewal tests with 10 days of exposure to the whole sediments and overlying water and measured survival in the CAX-CAD A sediment as statistically compared to survival in the Willoughby Bank Reference Site subsurface sediment (WBREF-SUB). The test protocols are detailed in the SAP (EA 2021), EA Ecotoxicology Laboratory Quality Assurance and Standard Operating Procedures Manual (EA 2018), and Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022). Results for whole sediment bioassays are summarized in Table 19.

Dredged material does not meet the benthic toxicity LPC when mean test organism mortality:

Is statistically greater than in the reference sediment, AND

Exceeds mortality (or other appropriate end point) in the reference sediment by at least 10 percent (or 20 percentage points for amphipods).

Ampelisca abdita A. abdita survival values in the CAX sediments were 97 and 91 percent and were not significantly less than the survival in the WBREF-SUB reference sample (92 percent) (Table 19). Survival in the CAX sediment samples was within the allowable percent difference (20 percent for amphipods) from the reference sample.

Leptocheirus plumulosus L. plumulosus survival values were 97 and 96 percent and were not significantly less than the survival in the WBREF-SUB reference sample (95 percent). Survival in the CAX sediment samples was within the allowable percent difference (20 percent for amphipods) from the reference sample.

LPC Compliance Survival in the whole sediment bioassays was not statistically different from the subsurface sample from Willoughby Bank Reference Site for either A. abdita or L. plumulosus. Therefore, the CAX CAD-A Pier sediments meet the LPC for benthic toxicity for placement at the NODS.

b. Benthic Bioaccumulation. Sediment from the CAX CAD-A Pier was evaluated in 28-day bioaccumulation studies with Nereis virens (sand worm) and Macoma nasuta (blunt-nose clam).

The studies measured survival of the test organisms and the potential for bioaccumulation of contaminants in organism tissue as a result of exposure to CAX CAD-A Pier sediment samples.

The bioaccumulation exposure and chemical testing protocols are detailed in the SAP (EA 2021a) and in Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022). Results of the benthic bioaccumulation survival/recovery are provided in Table 20.

Tissue Contaminant Analysis Following review of the bulk sediment data and completion of the 28-day bioaccumulation exposures, NAVFAC Mid-Atlantic consulted with USACE Norfolk District and USEPA Region 3 to determine the target constituents of concern for tissue analysis. USACE Norfolk District and USEPA Region 3 requested that CAX CAD-A tissue samples be analyzed for metals, PAHs, dioxin/furan congeners, select SVOCs, lipids, and percent moisture (EA 2022). Pre-test and WBREF-SUB tissues were also analyzed.

Detected concentrations of nonpolar organic constituents (PAHs, SVOCs, and dioxin and furan congeners) were lipid-normalized to account for partitioning of organic chemicals within organism tissue to facilitate comparison of data from different tissue replicates and comparisons to reference tissue and pre-test tissue concentrations.

Tissue Chemistry Results Details of the data analysis and statistical methods are provided in Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia (EA 2022). Results of the tissue analysis for N. virens and M. nasuta are summarized in Tables 21 through 24. Pre-test tissue concentrations that compare pre-exposure tissue concentrations to post-exposure concentrations are also provided in Tables 21 through 24.

The 95 percent upper confidence level of the mean (UCLM) tissue-residue concentrations for metals in worm and clam tissues exposed to the sediments from the CAX CAD-A Pier were compared to U.S. Food and Drug Administration (USFDA) Values (USFDA 2001) (Table 25).

Dredged material does not meet the benthic bioaccumulation LPC if the tissue concentrations are statistically greater than USFDA Action/Guidance/Tolerance Levels. None of the UCLM values for CAX CAD-A Pier tissues exceeded the USFDA Action/Guidance/Tolerance Values for metals (Table 25). There are no available USFDA Action/Guidance/Tolerance Levels for dioxin and furan congeners.

When tissue concentrations of contaminants of concern in organisms exposed to dredged material statistically exceed those of organisms exposed to the reference material, the dredged material has the potential to result in benthic bioaccumulation of contaminants. If the tissue concentrations statistically exceed those of organisms exposed to the reference site, the tissue concentrations are further evaluated to determine if placement of dredged material is likely to cause adverse effects.

Mean concentrations of analytes detected in the tissue samples exposed to sediment from the CAX CAD-A Pier were statistically compared to the mean concentrations of analytes detected in the tissue exposed to subsurface sediment from the Willoughby Bank Reference Site (WBREF-SUB) to evaluate the potential for adverse impacts. If the mean tissue concentrations statistically exceeded mean reference site concentrations and mean pre-test tissue concentrations, then mean concentrations were:

Statistically compared to USEPA Region 4 Background Tissue Concentrations for the South Atlantic Bight (USEPA/USACE 2008), and

Evaluated for analytical variability within the data set (reporting limiting substitutions for non-detected data, outliers, and compliance with laboratory quality assurance/quality control requirements).

None of the UCLM values for CAX tissues exceeded the USFDA Action/Guidance/Tolerance Levels for metals (Table 25). For CAX21-D/E, mean concentrations of lead and zinc in clam tissue statistically exceeded mean reference site and pre-test tissue concentrations (Table 21). However, the UCLM for lead and zinc in clam tissue did not exceed the USEPA background tissue concentrations for the South Atlantic Bight (Table 26). The mean OCDD concentration in clam tissue for CAX21-B/C1/C2 and CAX21-D/E statistically exceeded both the mean WBREF-SUB concentration and the mean pre-test concentration (Table 22). OCDD is the least toxic dioxin congener, is ubiquitous in the environment, and was also detected in the laboratory method blank for the tissue samples (both clams and worms). The mean dioxin toxicity equivalency quotient (ND=1/2RL and ND=RL) statistically exceeded both the mean reference and pre-test concentrations (Table 22); the statistical exceedances were driven by the substitution of the RLs and the lipid-normalization. PAHs and SVOCs were not detected in the tissue samples (Tables 23 and 24, respectively).

Based on the assessment of chemical analyses performed on tissues exposed to sediment from the CAX CAD-A Pier and WBREF-SUB reference sediment, it is anticipated that ocean placement of the dredged material from the CAX CAD-A Pier at the NODS will not result in ecologically significant bioaccumulation of contaminants and that the dredged material complies with the benthic bioaccumulation criteria of 40 CFR Part 227.13 (c) (3).

Overall, sediments from the CAX CAD-A Pier meet the criteria for the LPC for WQC, water column toxicity, benthic toxicity, and benthic bioaccumulation, indicating that ocean placement of the dredged material is a viable placement option. Based on the results of the STFATE modeling, placement events up to 14,000 cy comply with the LPC.

6. MPRSA SECTION 103 OCEAN DISPOSAL CRITERIA COMPLIANCE

EVALUATION

a. Compliance with 40 CFR Part 227 Subpart B – Environmental Impact. The following criteria were evaluated to determine that the proposed dredged material placement would not degrade the marine environment, and that the dredged material placement would not produce an unacceptable adverse effect on human health or on the ocean for other future uses.

1) The material to be dredged from the project area does not contain any of the prohibited materials listed in 40 CFR Section 227.5 including radioactive waste; material used in radiological, chemical, or biological warfare; or persistent inert synthetic or natural materials that may float and thus interfere with legitimate uses of the ocean. In addition, the material has been sufficiently described to make this determination.

2) The material does not contain any of the constituents prohibited as other than trace contaminants listed in 40 CFR Section 227.6 including organohalogen compounds, mercury and mercury compounds, cadmium and cadmium compounds, oil, or known carcinogens, mutagens, or teratogens.

3) The material to be disposed in the NODS is composed of naturally occurring sediment to be dredged from waters of the U.S. and does not meet the definition of waste materials listed in 40 CFR Section 227.7.

4) The material does not contain toxic waste as regulated under 40 CFR Section 227.8.

5) Although large quantities of dredged material are proposed for placement at the NODS, the site was designated with these quantities in mind and was located in an area and sized such that unacceptable impacts would not occur as described in 40 CFR Section 227.9.

6) The designation of the NODS took into account possible hazards to fishing, navigation, shorelines, and beaches. The material proposed for disposal at the NODS will be placed in such a manner as to not result in adverse impacts to the listed resources and as not to interfere with coastal navigation as described in 40 CFR Section 227.10.

7) The material proposed for disposal at the NODS is not required to be containerized as described in 40 CFR Section 227.11.

8) The dredged material does not contain any inert synthetic or natural material that may float or remain in suspension. Dredged material is natural sediment dredged from the waterways of the U.S. and is not considered to be solid waste as described in 40 CFR Section 227.12.

The materials to be dredged from the project area were not considered to meet the exclusion criteria. Appropriate testing has been performed and is described in earlier sections of this Section 103 Evaluation. The material has been determined to be in compliance with the requirements of 40 CFR Section 227.6 and there would be no violation of marine WQC after the allowance for mixing. Bioassays on the suspended particulate phase (elutriate) and solid phase

(whole sediment bioassay) show that the material can be discharged so as not to exceed the LPC as described in paragraph (b) of 40 CFR Section 227.27.

b. Compliance with 40 CFR Part 227 Subpart C – Need for Ocean Disposal. Upland placement at Port Tobacco at Weanack (Shirley Plantation) and upland landfill disposal and were both considered as placement options for the dredged material from the CAX CAD-A Pier. The dredged material meets the upland testing requirements for placement at Port Tobacco at Weanack (Shirley Plantation), the requirements for upland placement at some regional landfills, and the requirements for ocean placement at the NODS. Upland dredged material placement capacity is limited in the southern Virginia region and is preferential for projects with contaminated sediments that cannot meet the requirements for ocean or open-water placement.

Beneficial use (e.g., beach nourishment and shoreline stabilization) was also considered as a placement option for the dredged material from the CAX CAD-A Pier. The dredged material from the project site is primarily comprised of fine-grained silts and clays that are not suitable for beneficial use projects.

In additional to the NODS, another alternative identified to be feasible for dredged material placement of sediments from the CAX CAD-A Pier project was Craney Island Dredged Material Management Area (CIDMMA). Dredged material from the CAX CAD-A Pier project is precluded from placement at CIDMMA because CIDMMA is restricted to placement of material from dredging to support navigation in Norfolk Harbor and adjacent waters [USACE-Norfolk District Policy Memorandum WRD-01]. Cheatham Annex is geographically located outside of the CIDMMA service area. In addition, the CIDMMA is currently experiencing a shortfall of suitable dike-raising material to construct required capacity to accommodate dredged material volumes from the deepening of the Norfolk Harbor, dredging for maintenance of federal navigation channels, and other planned future inflows for navigation-related dredging (USACE 2021). At this time, placement capacity at CIDMMA is reserved for material from the deepening of the Norfolk Harbor and is limited to other materials comprised of sands that would be suitable for dike construction. Physical testing of the dredged material from the CAX CAD-A Pier footprint indicated that the sediments would not be suitable for dike construction.

Therefore, because of the need to reserve limited upland placement capacity within the region for future projects with contaminated sediment, because the CAX CAD-A Pier material meets the ocean placement criteria, and because that material is not located within the geographic area approved for placement at CIDMMA, and because the dredged material is not suitable for dike construction at CIDMMA, placement of the dredged material at the NODS is the most viable option. Following the guidance in the Ocean Testing Manual (USEPA/USACE 1991), Tier II and III testing was completed by examining physical and chemical properties of the sediment, water column and whole sediment bioassays, and bioaccumulation potential (tissue chemistry) (EA 2022). Because the material meets the ocean placement requirements and because the NODS has sufficient capacity for the material, the most viable option for the dredged material from the CAX CAD-A Pier is ocean disposal at the NODS. Placement of the dredged material from the CAX CAD-A Pier will reserve limited upland placement capacity for contaminated sediments and will be protective of the resources at the NODS.

c. Compliance with 40 CFR Part 227 Subpart D – Impact of the Proposed Dumping on Aesthetic, Recreational, and Economic Values. The following factors have been considered in making the determination that the proposed placement will not impact aesthetic, recreational, or economic values of the Atlantic Ocean in the vicinity of the NODS:

1) The area has been used in the past for the disposal of dredged material and has not resulted in negative impacts to potential recreational or commercial activities.

2) Based on past use of the area and the characteristics of the material proposed for placement, no impact to water quality is to be expected. The material will be discharged from bottom dump scows with the initial point of discharge being approximately 10 ft below the surface of the water. Based on results of the STFATE model, no applicable water quality standards will be violated by the proposed activity.

3) The material proposed for discharge contains substantial quantities of fine-grained silts and clays. The point of initial discharge is below the surface of the water and the majority of the material will be entrained into the disposal surge, which is in a downward direction because of gravity. Studies indicate that any turbidity caused by placement is restricted to the immediate vicinity and persists for only a short period of time.

4) Pathogenic organisms are not expected to be present in the material. However, if present they would likely be fecal coliforms that are killed by saline waters and therefore would not pose any impact to fisheries. No shellfisheries are located in the vicinity of the NODS.

5) No toxic chemical constituents are present in the dredged material in concentrations suspected of affecting humans either directly or indirectly through the food chain. There are no constituents in the dredged material that would impact living marine resources of any value.

d. Compliance with 40 CFR Part 227 Subpart E – Impact of the Proposed Dumping on Other Uses of the Ocean. The proposed placement of dredged material in the NODS would have no long-term impact on any other uses of the ocean including, but not limited to, commercial and recreational fishing, commercial and recreational navigation, mineral exploration or development, or scientific research. Short-term impacts may occur because of the presence of the tugs and scows in the NODS; however, this is extremely short term and all uses of the ocean would continue to occur in the area between placement events. No irreversible or irretrievable commitment of resources would result from the proposed discharge.

7. MPRSA SECTION 103 CONDITIONS

a. Requirements to Meet Ocean Disposal Criteria. No special requirements have been designated to meet the ocean disposal criteria.

b. Requirements of Site Designation Conditions. Disposal shall occur no less than 330 ft (100 meters) inside the NODS boundaries to comply with 40 CFR 227.28. A placement zone within the NODS has been designated for the project by USEPA Region 3 and USACE Norfolk

District (Figure 4). Placement will target even distribution of the dredged material across the placement zone. NAVFAC or its contractors will perform after-placement bathymetric surveys of the designated placement area within the NODS. These surveys may be performed periodically to ensure compliance with the NODS site conditions and SMMP. Other surveys may be performed as necessary.

c. Requirements of the Site Monitoring and Management Plan (SMMP). The SMMP was renewed by USEPA Region 3 and USACE Norfolk District in 2019 (USACE Norfolk District/USEPA Region 3 2019). It is not anticipated that dredging and placement operations will impact sea turtles, Atlantic sturgeon or other marine mammals (National Oceanic and Atmospheric Administration [NOAA] National Marine Fisheries Service 2018). Placement activities (vessel traffic to and from the NODS) will be conducted in compliance with the NOAA Fisheries Right Whale Ship Strike Reduction Rule (50 CFR 224.105), which limits vessels greater than 65 ft to speeds less than 10 knots during migration and calving periods.

8. FUTURE TESTING

Future testing requirements for continued placement of material at the NODS and for Section 103 concurrence renewals for CAX will be based on coordination with USACE Norfolk District and USEPA Region 3. Results of previous testing (2011, 2017/2018, and 2021/2022) may be used to justify modifications to subsequent sampling and testing programs.

9. REFERENCES

Canadian Council of Ministers of the Environment. 2001. Canadian sediment quality guidelines for the protection of aquatic life: Polychlorinated dioxins and furans (PCDD/Fs), in Canadian Environmental Guidelines. Winnipeg.

CH2M. 2018. Field Investigation and Analytical Evaluation Report: Sediment Sampling to

Support Ocean Placement or Upland Disposal of Dredged Material at CAD-A Pier.

NAVFAC-MIDLANT. June.

EA Engineering, Science, and Technology, Inc. (EA). 2012. Evaluation of Dredged Material:

Cheatham Annex CAD-A Pier Slips – York River, Virginia. Prepared for NAVFAC- MIDLANT. March.

EA Engineering, Science, and Technology, Inc., PBC (EA). 2018. EA Ecotoxicology Laboratory

Quality Assurance and Standard Operating Procedures Manual. EA Manual ATS-102.

Internal document prepared by EA’s Ecotoxicology Laboratory, Hunt Valley, Maryland.

———. 2021. Sampling and Analysis Plan – Evaluation of Dredged Material Proposed for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia. Prepared for NAVFAC-MIDLANT. November. Final.

———. 2022. Evaluation of Dredged Material for Ocean and Upland Placement: Naval Weapons Station Yorktown and Cheatham Annex, York River, Virginia. Prepared for NAVFAC- MIDLANT. April. Draft

Geo-Marine Inc. Tier III Sediment Evaluation Report 2004. Yorktown Ammunition Pier, Naval

Weapons Station, Yorktown, Virginia and Cheatham Annex Cargo Handling Pier, Cheatham Annex, Williamsburg, Virginia. Prepared for: Atlantic Division, Naval Facilities Engineering Command. July.

MacDonald, D.D., R.S. Carr, F.D. Calder, E.R. Long, and C.G. Ingersoll. 1996. Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5(4):253– 278.

National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service.

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