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HomeMy WebLinkAbout20230523 NOI_Part 6B_SD1 Player, Christine Subject:FW: FINAL SAP for Barnstable 10 Year Dredging and Beach Nourishment Project -----Original Message----- From: Loyd, Richard B CIV USARMY CENAE (US) <Richard.B.Loyd@usace.army.mil> Sent: Thursday, April 09, 2020 11:09 AM To: Jacek, Christine M CIV USARMY CENAE (USA) <Christine.M.Jacek@usace.army.mil>; Player, Christine <Christine.Player@foth.com> Cc: Farris, Charles N CIV USARMY CENAE (USA) <Charles.N.Farris@usace.army.mil> Subject: FINAL SAP for Barnstable 10 Year Dredging and Beach Nourishment Project Hello Christine, Attached is the final sampling and analysis plan for the Barnstable 10 year dredging and beach nourishment project. Please let me know when the sampling effort has been scheduled so that we can be prepared to discuss additional core locations in the event that you encounter fine grained material within the proposed dredge footprint. Contact me if you have any questions regarding the sampling methodology or data deliverables. Once the final data package is ready please e-mail it to me and CC everyone included on this e-mail. Please note that DEP has concurred with the attached plan, so you should be able to disregard the plan that you independently coordinated. Regards, Ben Richard B. Loyd US Army Corps of Engineers 696 Virginia Road Concord, MA 01742 Office: (978) 318-8048 Cell: (978) 763-5438 Richard.B.Loyd@usace.army.mil 1 CENAE-PDE 1 August 2022 FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 Summary This supplemental determination addresses the suitability of dredged material from the proposed dredging of nine channels and basins in the Town of Barnstable for beach nourishment as well as the suitability of dredged material from the proposed dredging of one channel for unconfined open water disposal at the Cape Cod Bay Disposal Site (CCBDS).The New England District (NAE) of the U.S. Army Corps of Engineers (USACE) finds that sufficient data has been provided to satisfy the evaluation and testing requirements of Section 404 of the Clean Water Act (CWA). Based on an evaluation of the project and the material proposed to be dredged, NAE finds the following channels suitable for beach placement (Figures 1-5): Centerville River Spur Channel, Bumps River Channel, Cotuit Bay Embayment Channel (-11ft MLW), West Bay Spur Channel, and Prince Cove Entrance Channel. NAE also finds portions of the following channels suitable for beach placement and portions of these channels unsuitable for beach placement (Figures 1-5): Centerville River Upper Reach Channel, Cotuit Bay Embayment Channel (-9ft MLW), West Bay Inner Entrance Channel, North Bay Bay Street Channel, and the Prince Cove Marina Basin. The North Bay Bay Street Channel is suitable for unconfined open water disposal at CCBDS (Figure 4). 1. Background In April of 2020 NAE prepared a Sampling and Analysis Plan (SAP) for the Town of Barnstable 10-year Comprehensive Dredge and Beach Nourishment Program (NAE-2015-01632) and sampling was completed in April and May of 2020. The project proposed dredging of several channels and basins in the Town of Barnstable for beach nourishment. In September of 2020, NAE prepared a suitability determination for the Town of Barnstable project (Final Suitability Determination, Appendix I). The 2020 suitability determination concluded that five of these channels met the exclusionary criteria under §230.60(a) and were suitable for 10-year beach nourishment and four channels were suitable for one- time beach placement (Table 1). Proposed dredge depths, project volumes, and the 2020 finding for each area is shown in Table 1 and the conceptual site model for each region is located in the Final Suitability Determination (Appendix I). FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 2 In March of 2021, NAE prepared a supplemental sampling and analysis plan (supplemental SAP, Appendix II) to further evaluate several channels for beach nourishment that did not meet the exclusionary criteria under §230.60(a) due to grain size, location, or other characteristics that indicated there was a potential for contamination. Additional sampling was also conducted to evaluate the North Bay Bay Street Channel for offshore disposal at the CCBDS. FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015-01632 3 Table 1: Summary of Proposed Dredge Areas and Placement Sites 2020 Waterway Project Area and Depth (FT MLW) 2020 Finding Current Dredge Footprint (Acres) Current Dredge Volume (CY) Proposed Placement Sites Barnstable Harbor-Sandy Neck - Total Volume: 1,305 CY Barnstable Harbor Entrance Channel: -6 suitable for 10-year beach nourishment 2 1,305 Millway Beach, Sandy Neck Public Beach Centerville Harbor - Total Volume: 18,752 CY East Bay Entrance Channel: -6 suitable for 10-year beach nourishment 3.2 149 Long Beach, Craigville Beach, Covell’s Beach Centerville River Lower Reach Channel: -6 suitable for one time beach placement 10.4 18,386 Upper Reach Channel: -6 additional testing Spur Channel: -4 additional testing Bumps River Channel: -4 additional testing 0.3 217 Three Bays - Total Volume: 155,768 CY Cotuit Bay Entrance Channel: -8 suitable for 10-year beach nourishment 28.3 44,830 Dead Neck, Cross St. (Riley’s) Beach, Ropes Beach Embayment Channel: -7 suitable for one time beach placement Embayment Channel: -9 additional testing Embayment Channel: - 10 suitable for 10-year beach nourishment Embayment Channel: - 11 additional testing Hoopers Landing: -6 not suitable Town Landing: -3.5 not suitable West Bay Entrance Channel: -8 suitable for 10-year beach nourishment 18.2 63,675 Inner Channel: -11 additional testing Spur Channel: -8 additional testing North Bay Narrows Channel: -8 suitable for one time beach placement 23.7 39,221 Bay St Channel: -6 additional testing Seapuit River Channel -6 and -7 suitable for one time beach placement 7.4 8,042 Prince Cove - Total Volume: 12,748 CY Prince Cove Entrance Channel: -6 additional testing 10.6 12,748 Dead Neck, Cross St. (Riley’s) Beach, Ropes Beach Marina Basin: -6 additional testing Note: Areas shown in gray are not assessed in this suitability determination addendum FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 4 2. Sampling, Testing, and Analysis The applicant collected dredge area sediment cores in August of 2021. The reported sample locations and core lengths are presented in Table 2 and core logs and photos are provided in Appendix III. FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015-01632 5 Table 2: 2021 Sampling Locations and Core Lengths * TBR-WB-5A top sample taken from first attempt, bottom sample taken from second attempt Station ID Longitude Latitude Project Depth with overdepth (FT MLLW) Water Depth (FT MLLW) Target Core Length (FT) Penetration (FT) Recovery (FT) Sample Interval (FT) Grain Size Sample Chemistry Sample CH-UR-1 -70.3566 41.6344 -7 -6.4 0.6 1.1 1.1 0-1.1 X CH-UR-1R -70.3529 41.6358 -7 -5.7 1.3 1.3 1.3 0-0.5; 0.5-1.3 X CH-UR-2R -70.3510 41.6370 -7 -4.5 2.5 2.6 2.4 0-1.2; 1.2-2.4 X CH-UR-3R -70.3492 41.6370 -7 -2.8 4.2 4.2 4 0-1.3; 1.3-4.0 X CH-S-1 -70.3452 41.6390 -5 -0.8 4.2 5.8 4.9 0-4.2 X CH-S-2 -70.3472 41.6382 -5 -2.9 2.1 4.8 4.1 0-1.3; 1.3-2.1 X CH-S-3 -70.3481 41.6374 -5 -4.8 0.2 2.3 2.1 0-0.3 X CH-BR-1 -70.3577 41.6347 -5 -3.4 1.6 4.0 4 0-1.6 X TBR-CB-5 -70.4302 41.6080 -12 -11.1 0.9 1.2 1.1 0-0.9 X TBR-CB-7 -70.4273 41.6121 -10 -7.9 2.1 2.6 2.4 0-1.3; 1.3-2.2 X TBR-NB-1 -70.3964 41.6194 -9 -7.6 1.4 1.5 1.3 0-1.3 X TBR-NB-1A -70.3958 41.6201 -9 -7.6 1.4 2.3 2.3 0-1.4 X TBR-NB-2 -70.3964 41.6220 -9 -5.6 3.4 4.5 4.1 0-3.4 X TBR-NB-2A -70.3960 41.6249 -9 -7.2 1.8 2.0 1.6 0-1.6 X TBR-NB-3 -70.3960 41.6246 -9 -7.5 1.5 1.9 1.5 0-1.5 X TBR-NB-3A -70.3960 41.6273 -9 -7.4 1.6 2.8 2.1 0-1.6 X TBR-NB-4 -70.3983 41.6287 -9 -6 3 3.1 2.8 0-2.7 X TBR-NB-4A -70.4011 41.6300 -9 -7 2 2.2 2 0-2 X TBR-NB-5 -70.4027 41.6305 -9 -5.7 3.3 3.7 3.4 0-3.4 X TBR-WB-2 -70.4024 41.6083 -9 -8 1 1.0 0.8 0-0.8 X X TBR-WB-3 -70.4008 41.6102 -12 -8.5 3.5 3.6 3.2 0-3.2 X TBR-WB-4 -70.4004 41.6137 -12 -8.9 3.1 3.6 3.2 0-1.3; 1.3-3.2 X TBR-WB-5 -70.4008 41.6166 -12 -8.8 3.2 3.3 2.8 0-0.9; 0.9-2.8 X TBR-WB-5A* -70.4007 41.6178 -12 -8.1 3.9 4.1 3.3 0-2.5 X TBR-WB-5A* -70.4007 41.6178 -12 -8.3 3.7 4.3 3.7 2.3-3.7 X TBR-WB-6 -70.3996 41.6188 -12 -9 3 3.5 3 0-1; 1-3 X PC-C-1 -70.4066 41.6366 -7 -6.5 0.5 1.4 1.3 0-1.2 X PC-C-3 -70.4052 41.6400 -7 -3.1 3.9 4.1 3.8 0-1.8; 1.8-3.4 X PC-C-5 -70.4077 41.6439 -7 -6.4 0.6 0.9 0.9 0-0.9 X PC-B-1 -70.4095 41.6445 -7 -3.9 3.1 3.8 3.8 0-3.8 X PC-B-4R -70.4109 41.6438 -7 -4.8 2.2 2.7 2.7 0-1.8; 1.8-2.2 X PC-B-5R -70.4110 41.6448 -7 -5.2 1.8 2.7 2.7 0-2.7 X FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 6 3. Chemistry and Grain Size Testing Results 2021 The supplemental SAP called for selected samples to be analyzed for grain size to further delineate silty areas while others were analyzed for chemistry to evaluate suitability for beach placement or offshore disposal. For bulk sediment chemistry analysis, the samples were analyzed for the standard suite of contaminants specified in the Regional Implementation Manual for the Evaluation of Dredged Material Proposed for Disposal in New England Waters (RIM) (EPA/USACE, 2004), as no project specific contaminants of concern were identified in the CSM. To examine the sediment concentrations in an ecologically meaningful context, NAE used Sediment Quality Guidelines (SQGs) to screen the chemical concentrations found in the sediment samples from the Town of Barnstable. Applicable SQG screening values for marine and estuarine sediments are the National Oceanic and Atmospheric Administration (NOAA) effects-range low (ERL) and effects-range median (ERM). It is important to understand that these values were not derived as toxicity pass-fail thresholds. Rather, ERL and ERM values are empirically derived guidelines based on a large number of studies nationwide that identify contaminant levels that indicate probability of toxic effects to inform decision making (Long et al., 1998). Effects are considered unlikely at concentrations below the ERL with an increased probability of toxic effects as concentrations increase. At concentrations above the ERM, toxic effects are considered likely. For samples with sediment concentrations that fall between the ERL and ERM levels, consideration is given to both the number of contaminants that exceed ERL values and where the concentrations fall in the range between ERL and ERM values in assessing the probability of toxic effects and the potential need for additional testing. In addition, applicable MassDEP screening values include the Massachusetts Contingency Plan ([MCP] 310 CMR 40) “reportable concentrations soil-1” (RCS- 1) values which are for soils within 500 feet of a dwelling or recreational area and the Similar Soils Provision Guidance ([SSPG], MassDEP 2014) RCS-1 values. The SSPG Reporting Category RCS-1 applies to locations with the highest potential for exposure, such as residences, playgrounds and schools, and to locations within the boundaries of a groundwater resource area. The samples from the Town of Barnstable project were compared to these values in addition to the NOAA ERL and ERM in order to assess suitability for beach placement. A summary of the grain size and bulk sediment chemistry results is discussed FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 7 by channel below. There were no exceedances of the MassDEP SSPG-RCS-1 or MCP RCS-1 values. The full bulk chemistry results can be found in Appendix IV. Centerville Harbor: Centerville River Upper Reach Channel, Spur Channel, and Bumps River Channel Three cores were collected for grain size analysis and two individual cores and one composite sample were collected for bulk chemistry analysis (Figure 1). The grain size distributions, sediment color, and chemistry sample compositing information are shown in Table 3. Samples CH-UR-3R (0-1.3’ and 1.3-4.0’), CH-BR-1, CH-S-2 (A and B), and CH- S-3 were composed of black, brown, and gray sand with less than 8% fines. Samples CH-UR-1R (0-0.5’ and 0.5-1.3’), and CH-UR-1 were predominantly black to gray sand with 10.5-14.6% fines. Sample CH-UR-2R was composed of a light to dark gray sand in the top 1.2 feet but was composed of a brown silty sand with 27.5% fines from 1.2-2.3 feet. All analyte concentrations in samples CH-UR-1, CH-BR-1, and COMP-CH-S-1,2,3 were below the ERL. All pesticides and polychlorinated biphenyls (PCBs) were non-detect in samples CH-UR-1 and CH-BR-1. The Long Beach, Craigville Beach, and Covell’s Beach nourishment area grab samples were composed of fine to medium sand (Final SD, Appendix B) FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015-01632 8 Table 3. Grain Size Data Centerville Harbor Year of Grain Size Sample 2021 2020 Reach Upper Reach Channel Bumps River Channel Spur Channel Sample ID CH-UR-1R CH-UR-2R CH-UR-3R CH- UR-1 CH-BR-1 CH-S-1 CH-S-2 CH-S-3 0-0.5' 0.5- 1.3' 0-1.2' 1.2- 2.3' 0-1.3' 1.3-4.0' CH-S- 2-A CH-S- 2-B Total Gravel 0.4 0.7 15.3 2.7 29.7 1.2 0 0 0 0 29.1 1.2 Coarse Sand 1.6 1.0 2.5 2.6 2.3 6.5 0.8 0.4 1.5 0.3 7.8 1.8 Medium Sand 28.6 35.9 37.3 30.0 50.1 83.9 38.3 22.7 59.9 26.2 39.8 69.1 Fine Sand 57.3 47.8 41.2 37.2 15.7 7.0 43.6 72.5 36.5 65.7 22.2 26.9 Total Fines 12.1 14.6 3.70 27.5 2.2 1.4 10.5 4.4 2.0 7.8 1.1 1.0 Color black black to gray light to dark gray brown brown light gray gray to black medium gray light to medium gray black gray light to medium gray Chemistry Sample ID NA NA NA CH- UR-1 CH-BR-1 COMP-CH-S-1,2,3 NA=not applicable FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 9 Three Bays Region: Cotuit Bay Embayment Channel Two cores were collected from the Cotuit Bay Embayment Channel, one from the -11ft MLW section and one from the -9ft MLW section, for bulk chemical analysis (Figure 2). The grain size distributions, sediment color, and chemistry sample compositing information are shown in Table 4. Samples TBR-CB-5 and TBR-CB-7 were predominantly black to gray sand with 9-12.4% fines. All analyzed contaminants of concern (COCs) were below the ERL. The associated Cross Street Beach nourishment area samples were composed of medium and fine-medium sand. The Ropes Beach nourishment area samples were composed of fine to medium sand and the Dead Neck Beach nourishment area samples were composed of medium sand and sandy gravel (Final SD, Appendix B). Table 4. Grain Size Data Cotuit Bay Embayment Channel Year of Grain Size Sample 2020 Reach Cotuit Bay Embayment Channel (-11 and -9 ft MLW) Sample ID TRB-CB-5 TRB CB-7 Total Gravel 14.2 7.0 Coarse Sand 8.4 3.4 Medium Sand 24.3 36.7 Fine Sand 40.7 43.9 Total Fines 12.4 9.0 Color black/dark gray black/gray Chemistry Sample ID COMP-TBR-CB-5,7 Three Bays Region: West Bay Spur and Inner Entrance Channel Four cores were taken from the West Bay Spur and Inner Entrance channels for grain size analysis, one core and one composite sample were analyzed for chemistry (Figures 3). Two cores were taken at station TBR-WB-5A to achieve sufficient volume for the sample. The grain size distributions, sediment color, and chemistry sample compositing information are shown in Table 5. FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 10 Samples TBR-WB-2, TBR-WB-3, and TBR-WB-4 were composed of predominantly black, dark gray, and tan sand with less than 6.2% fines. Samples TBR-WB-5, TBR-WB-5A, and TBR-WB-6 were stratified with a tan or dark brown sand in the bottom layer. Samples TBR-WB-5 and TBR-WB-5A had upper layers composed of a black to dark gray silty sand with 22.1-32.5% fines. The upper layer of sample TBR-WB-6 was a black sand with 14.6% fines. All analyzed COCs in the composite sample COMP-TBR-WB-3,4 and sample TBR-WB-2 were below the ERL. Beach nourishment area grain size data can be found in the Final SD, Appendix B. Table 5. Grain Size Data West Bay Inner Entrance and Spur Channels Year of Grain Size Sample 2021 2020 2021 Reach Spur Channel Inner Entrance Channel Sample ID TBR-WB- 2 TRB-WB- 3 TRB-WB- 4 TBR-WB-5 TBR-WB-5A TBR-WB-6 0-0.9' 0.9- 2.8' 0-2.8' 2.3- 3.7' 0-1.0' 1.0- 3.0' Total Gravel 2.5 3.9 24.6 6.3 4.6 0 3.8 4.5 3.0 Coarse Sand 0.8 6.9 4.8 2.0 2.3 2.9 2.7 2.9 4.3 Medium Sand 3.8 45.7 35.0 19.6 61.3 46.1 50.5 42.3 59.8 Fine Sand 86.7 39.3 32.9 50.0 29.0 18.5 37.3 35.5 31.6 Total Fines 6.2 4.2 2.7 22.1 2.80 32.5 5.70 14.8 1.3 Color black dark gray black and tan black tan dark gray dark brown black tan Chemistry Sample ID TBR-WB- 2 COMP-TBR-3,4 NA NA NA NA NA NA NA=Not Applicable Three Bays Region: North Bay Bay Street Channel One individual core and three composite samples were taken from the North Bay Bay Street Channel for chemical analysis (Figure 4). The grain size distributions, sediment color, and chemistry sample compositing information are shown in Table 6. Samples TBR-NB-2A, TBR-NB-3, TBR-NB-3A, TBR-NB-4, and TBR-NB-4A were composed of dark gray to black sand with 3.5-10.1% fines. Samples TBR-NB-1 FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 11 and TBR-NB-2 were composed of a black to gray silty sand with 17.7-38.6% fines and samples TBR-NB-1A and TBR-NB-5 were predominantly black silt with 61.7- 90.1% fines. The concentrations of all analytes in the three composite samples were below the ERL. Arsenic in sample TBR-NB-5 slightly exceeded the ERL but was below the CCBDS reference value. All other analytes in sample TBR-NB-5 were below the ERL. Beach nourishment area grain size data can be found in the Final SD, Appendix B. FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015-01632 12 Table 6. Grain Size Data North Bay Bay Street Channel Year of Grain Size Sample 2020 Reach Bay Street Channel Sample ID TBR-NB- 1 TBR-NB- 1A TBR-NB- 2 TBR-NB- 2A TBR-NB- 3 TBR-NB- 3A TBR-NB- 4 TBR-NB- 4A TBR-NB- 5 Total Gravel 11.6 7.4 2.7 0.9 2.4 4 9.8 8.6 0 Coarse Sand 11 5.5 5 4.2 4.7 4 5.5 5 1.3 Medium Sand 39.3 11.9 19.7 44.1 53.6 48.5 53.1 47.3 4.4 Fine Sand 20.4 13.5 34 44.8 32.5 35.8 28.1 29 4.2 Total Fines 17.7 61.7 38.6 6 6.8 7.7 3.5 10.1 90.1 Color black black medium gray dark gray dark gray dark gray medium to dark gray black black Chemistry Sample ID COMP-TBR-NB-1,1A,2 COMP-TBR-NB-2A,3 COMP-TBR-NB-3A,4,4A TBR-NB- 5 FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 13 Prince Cove: Prince Cove Entrance Channel and Marina Basin Two cores were collected for grain size analysis and one individual core and one composite sample were collected for bulk chemistry analysis (Figure 5). The grain size distributions, sediment color, and chemistry sample compositing information are shown in Table 7. Samples PC-C-1, PC-C-2, and PC-C-3 were composed of black to gray sand with less than 4% fines. Samples PC-B-1 and the top 1.8’ of core PC-B-4R were composed of black sand with 7.7-10.0% fines while the bottom 0.4 feet of core PC-B-4R was composed of a light brown sand with 1.2% fines. Sample PC-B-5R and the previously analyzed sample PC-B-3 were composed of black silt with 51.7-94.1% fines. Composite sample COMP-PC-C-1,3,5 had concentrations of all analytes below the ERL. Sample PC-B-1 had arsenic, 4,4’-DDE, and total DDX (sum 4,4’-DDD, 4,4’-DDE, 4,4’-DDT) concentrations slightly above the ERL. Beach nourishment area grain size data can be found in the Final SD, Appendix B. Table 7. Grain Size Data Prince Cove Marina Basin Year of Grain Size Sample 2020 2021 Reach Entrance Channel Marina Basin Sample ID PC-C-1 PC-C-3 PC-C-5 PC-B-1 PC-B-4R PC-B- 5R 0-1.8' 1.8- 2.2' Total Gravel 10.0 32.9 1.3 11.8 3.7 0.4 0.0 Coarse Sand 3.9 8.9 1.7 2.3 3.8 2.0 1.9 Medium Sand 41.8 35.8 25.8 20.9 44.3 55.3 1.9 Fine Sand 40.9 20.8 67.2 57.3 38.2 41.1 2.1 Total Fines 3.4 1.6 4.0 7.7 10.0 1.2 94.1 Color black gray/black to light gray black black black light brown black Chemistry Sample ID COMP-PC-C-1,3,5 PC-B-1 NA NA NA FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 14 4. Suitability Determination Based on the weight of evidence including the conceptual site model, low- moderate project risk ranking, grain size results, and consistently low sediment chemistry results for these sediments, according to the testing and evaluation requirements set forth in Section 404 of the Clean Water Act (CWA), NAE finds the following: Centerville Harbor: Centerville River Upper Reach Channel, Spur Channel, and Bumps River Channel (Figure 1) The Centerville River Spur Channel, Bumps River Channel, and portions of the Centerville River Upper Reach Channel, represented by samples CH-UR-1, CH- UR-1R and CH-UR-3R as well as the previously analyzed sample CH-UR-3, were predominately composed of sand with low sediment chemistry results and are suitable for one-time beach placement. The portions of the Centerville River Upper Reach Channel represented by sample CH-UR-2R, as well as the previously analyzed samples CH-UR-2, CH-UR-4, and CH-UR-5, were composed of 22.9% to 86.8% fine grained material and are unsuitable for beach placement. Three Bays Region: Cotuit Bay Embayment Channel (Figure 2) The Cotuit Bay Embayment Channel -11ft MLW segment and the portion of the Cotuit Bay Embayment Channel -9ft MLW segment represented by sample TBR- CB-7, as well as the previously analyzed sample TBR-CB-8, were predominately composed of sand with low sediment chemistry results and are suitable for one- time beach placement. The portion of the Cotuit Bay Embayment Channel -9ft MLW segment represented by the previously analyzed sample TBR-CB-7A contained a higher percentage of fines and is unsuitable for beach placement. Three Bays Region: West Bay Spur and Inner Entrance Channel (Figure 3) The West Bay Spur channel and the portions of the West Bay Inner Entrance Channel represented by samples TBR-WB-3, TBR-WB-4, and TBR-WB-6 were composed predominantly of sand with low sediment chemistry results and are suitable for one-time beach placement. The portion of the West Bay Inner Entrance Channel represented by samples TBR-WB-5 and TBR-WB-5A had a higher percentage of fines in the upper portion of each core and is unsuitable for beach placement. The Seapuit River Channel and West Bay Entrance Channel were found suitable for one-time beach placement and 10-year beach nourishment, respectively, in the 2020 Final SD (Appendix I). FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 15 Three Bays Region: North Bay Bay Street Channel (Figure 4) The portion of the North Bay Bay Street channel represented by samples TBR- NB-2A, TBR-NB-3, TBR-NB-3A, TBR-NB-4, and TBR-NB-4A was predominantly composed of sand with low sediment chemistry results and is suitable for one- time beach placement. The portions of the North Bay Bay Street Channel represented by samples TBR-NB-1, TBR-NB-1A, TBR-NB-2, and TBR-NB-5 contained higher percentages of fines and are unsuitable for beach placement. The sediments to be dredged from the North Bay Bay Street channel do not pose an unacceptable risk to the environment and are considered suitable for unconfined open water placement at CCBDS. Prince Cove: Prince Cove Entrance Channel and Marina Basin (Figure 5) The Prince Cove Entrance channel and portions of the Prince Cove Marina Basin represented by samples PC-B-1, PC-B-4R, and the previously analyzed sample PC-B-2 were predominately composed of sand with low sediment chemistry results and are suitable for one-time beach placement. The portions of the Prince Marina Basin represented sample PC-B-5R and the previously analyzed sample PC-B-3 were predominantly fine grained and are unsuitable for beach placement. FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 16 The results of this determination are summarized in Table 8. The channels evaluated in this addendum are not suitable for 10-year beach nourishment due to the presence of fine-grained material within or adjacent to these channels and the potential for finer grained material to accumulate in these depositional environments.. Five years from the date of this Suitability Determination Addendum, a Tier One project review by NAE will be required before additional dredging can take place. This will include a review of spill records, updated hydrographic surveys, and any changes in the project area to determine if the findings in this suitability determination remain valid or if additional sampling and testing is required. This suitability determination was coordinated with EPA Region 1 and MADEP. MADEP concurred with the determination and EPA Region 1 conducted an individual evaluation of the project and documented their findings in a separate memo. _________________________________ ________________________________ Sarah Turner Geologist Dredged Material Management Team USACE-New England District Lawrence Oliver Chief Environmental Branch USACE-New England District FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 17 Table 8: Suitability Summary Channel Decision Volume CY (with OD) Placement Area Centerville Harbor Centerville River Upper Reach Channel Partially suitable/partially unsuitable for one time beach placement 12,112 Long Beach Craigville Beach Covell’s Beach Centerville River Spur Channel suitable for one time beach placement 2,518 Bumps River Channel suitable for one time beach placement 217 Three Bays Region Cotuit Embayment Channel (-9 MLW) Partially suitable/partially unsuitable for one time beach placement 10,367 Dead Neck Beach Cross St. (Riley's) Beach Ropes Beach Cotuit Embayment Channel (-11 MLW) suitable for one time beach placement 7,386 West Bay Spur Channel suitable for one time beach placement 775 West Bay Inner Entrance Channel Partially suitable/partially unsuitable for one time beach placement 62,100 Bay Street Channel Partially suitable/partially unsuitable for one time beach placement; suitable for CCBDS 30,507 Prince Cove Prince Cove Entrance Channel suitable for one time beach placement 9,014 Dead Neck Beach Cross St. (Riley's) Beach Ropes Beach Prince Cove Marina Basin Partially suitable/partially unsuitable for one time beach placement 3,734 FINAL Suitability Determination Addendum for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, NAE-2015- 01632 18 References: EPA/USACE 2004. Regional Implementation Manual for the Evaluation of Dredged Material Proposed for Disposal in New England Waters. U.S. EPA Region 1, Boston, MA/U.S. Army Corps of Engineers, New England District, Concord, MA. EPA/USACE 1998. Evaluation of Dredged Material Proposed for Discharge in Waters of the U.S.– Testing Manual. Environmental Protection Agency, Office of Water and Department of the Army, United States Army Corps of Engineers. Washington, D.C Long E.R & MacDonald D.D. 1998. Recommended Uses of Empirically Derived, Sediment Quality Guidelines for Marine and Estuarine Ecosystems, Human and Ecological Risk Assessment: An International Journal, 4:5, 1019-1039. 19 20 Appendix I 2020 Suitability Determination 1    CENAE-PDE 14 September 2020 FINAL Suitability Determination for the Town of Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 Summary: This determination addresses the suitability of dredged material from the proposed dredging of 21 channels and basins in the Town of Barnstable for beach nourishment. Based on Clean Water Act (CWA) 404(b)(1) guidelines the New England District (NAE) of the US Army Corps of Engineers (USACE) finds the sediments from five of these channels suitable for 10-year beach nourishment and the sediments from four of the channels suitable for one-time beach placement. The sediments from the remaining channels and basins are unsuitable for beach nourishment but may be suitable for other disposal options including, nearshore placement or open water disposal which will require additional sampling and testing.   1. Project Description: The Town of Barnstable is preparing a 10-year comprehensive plan for maintenance dredging of the historically sandy portions of the town channels in Barnstable Harbor, Centerville Harbor, the Three Bays Region, and Prince Cove (Figure 1). Suitable sandy material from these areas will be used to nourish beaches in the vicinity of each project (see Table 1 and Figures 2-5). The current plan for the 2020 dredge cycle includes the removal of approximately 188, 573 cubic yards (CY) of predominantly sandy material from shoals totaling 104 acres across the four project areas. All project areas will be hydraulically dredged by the Barnstable County Dredge (BCD) to the various permitted depths plus one foot of allowable overdepth. Suitable sandy material will be placed across the 10 identified shoreline areas described in the sections below for the purpose of beach nourishment. The upland placement action proposed in the vicinity of Sandy Neck will not be evaluated in this determination as this site is not regulated under Section 404 of the CWA. A summary of the proposed dredge areas, volumes, depths, and proposed nourishment sites is presented by project area and waterway in Table 1. 2. Conceptual Site Model: NAE reviewed historic testing data, previous environmental assessments, water quality data, and adjacent land-use information to develop a conceptual site model (CSM) for each of the dredge areas specified in the Barnstable 10-Year Comprehensive Dredge & Beach Nourishment Program. This CSM was used to FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 2 contamination, site-specific contaminants of concern, exposure pathways, and biological receptors in order to inform this suitability determination. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 3 4 Table 1: Summary of Proposed Dredge Areas and Placement Sites 2020 Waterway Project Area and Depth (FT MLW) Current Dredge Footprint (Acres) Current Dredge Volume (CY) Proposed Placement Sites Barnstable Harbor-Sandy Neck - Total Volume: 1,305 CY Barnstable Harbor Entrance Channel: -6 2 1, 305 Millway Beach Sandy Neck Public Beach Centerville Harbor - Total Volume: 18,752 CY East Bay Entrance Channel: -6 3.2 149 Long Beach Craigville Beach Covell’s Beach Centerville River Main Channel:-6 Spur Channel: -4 10.4 18, 386 Bumps River Channel: -4 0.3 217 Three Bays - Total Volume: 155,649 CY Cotuit Bay Entrance Channel: -8 Embayment Channel: -7,-9,-10,-11 Hoopers Landing: -6 Town Landing: -3.5 28.3 44,830 Dead Neck Cross St. (Riley’s) Beach Ropes Beach West Bay Entrance Channel: -8 Inner Channel: -11 Spur Channel: -8 18.2 63,657 North Bay Narrows Channel: -8 Bay St Channel: -6 23.7 38,681 Seapuit River Channel -6 and -7 7.4 8,042 Prince Cove - Total Volume: 12,748 CY Prince Cove Entrance Channel: -6 Marina Channel and Basin: -6 10.6 12,748 Dead Neck Cross St. (Riley’s) Beach Ropes Beach FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 5 Barnstable Harbor – Sandy Neck: Barnstable Harbor, located approximately 10 miles east of the Cape Cod Canal entrance, is a natural harbor on the northern shore of Cape Cod. The harbor is home to a small recreational and commercial fishing fleet and is a popular destination for transient boaters. Access to the inner harbor is facilitated by a 6 foot deep (MLW), 60 foot wide channel that extends approximately 0.2 miles from deep water to the head of navigation along the town waterfront. Waterfront facilities include a Town Marina with 88 slips, fuel docks, parking, a public boat ramp, and several commercial marine service centers. The Sandy Neck Barrier Beach System shelters the north and northwest portion of Barnstable Harbor and was designated as an Area of Critical Environmental Concern (ACEC) in 1978 by the state due to the natural resources, wildlife, endangered species, and recreational opportunities found on site. Several residential properties are located on the southeast end of the Sandy Neck Peninsula. Water quality in the vicinity of Barnstable Harbor is dictated by tidal exchange with Cape Cod Bay to the north and freshwater input from several small creeks and streams to the south and west. The Commonwealth of Massachusetts designates the waters of Barnstable Harbor as Class SA (314 CMR 4.06). Class SA waters are considered excellent habitat for fish, other aquatic life, and wildlife, and are suitable for shellfish harvesting and for primary and secondary contact recreation (MassDEP 2018). The Barnstable Harbor channel requires periodic maintenance dredging in order to maintain a safe and navigable waterway. The outer entrance channel was last dredged by the Town in 2017 when 8,226 cubic yards of sand was hydraulically removed and placed along Millway Beach, Sandy Neck Public Beach, and in the Sandy Cottage area for beach nourishment. Sediment sampling and testing of the outer entrance channel performed in 2014 documented the material as predominantly coarse grained (93-98% sand and gravel). Dredging activities within Barnstable Harbor under the 10-year plan will be limited to the outer- most ±1,125 linear feet of the channel as this area has historically contained coarse grained sediments suitable for beach nourishment. Based on a review of available data and communication with local officials NAE determined that there has been one documented spill of gasoline (4-6 gallons) off of Salten Point, approximately 800 feet west of the dredge site. There are 2 known outfalls along the Barnstable harbor waterfront and 5 documented outfalls along Mill Creek, a tributary to the harbor. Following this tier one review of the site characteristics and the available historical data, the entrance channel of Barnstable Harbor was given a low-moderate risk ranking according to the following matrix (Table 2, adapted from USACE 2018): FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 6 Table 2. Project Risk Ranking Rank Guidelines Low Few or no sources of contamination. Data available to verify no significant potential for adverse biological effects. Low-Moderate Few or no sources of contamination but existing data is insufficient to confirm ranking. Moderate Contamination sources exist within the vicinity of the project with the potential to produce chemical concentrations that may cause adverse biological effects. High Known sources of contamination within the project area and historical data exists that has previously failed biological testing. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 7 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 8 Centerville Harbor: The Centerville Harbor region is located on the south side of Barnstable, approximately 3.5 miles west of the village of Hyannis. Navigable waterways within this region include the East Bay, Centerville River, and the Bumps River. The Bumps River and Centerville River both flow into the East Bay which empties into Nantucket Sound. The East Bay entrance channel is 6 feet deep (MLW), 0.4 miles long, and is flanked by Dowses Point to the west and Long Beach to the East. A stone jetty extends along the western shoreline at Dowses Point and provides stabilization to the East Bay Entrance channel. The Centerville River includes a 7 foot deep (MLW), 0.7 mile long lower reach channel; a 6 foot deep (MLW), 0.75 mile long upper reach channel; and 4 foot deep (MLW), 0.3 mile long spur channel. The Bumps River channel is 4 feet deep (MLW) and extends 0.07 miles upstream to a point between two residential neighborhoods. The East Bay-Centerville River system is an active waterfront that supports recreational boating activities, two public landings, and several private docks and piers. The Town of Barnstable manages a few dozen moorings within the Centerville River. Other land use in the area is a mix of low to moderate density residential properties along the northern and southern waterfront, and public recreation areas to the south along Nantucket Sound. The upstream portion of the Centerville River is bounded by an extensive system of salt marshes. Two public beaches, Long Beach and Craigville Beach, are located adjacent to the Centerville River channel. Water quality in the vicinity of Centerville Harbor is dictated by tidal exchange with Nantucket Sound to the south and freshwater input from the Centerville River and Bumps River to the north. The Commonwealth of Massachusetts designates the waters of Centerville Harbor as Class SA (314 CMR 4.06). Class SA waters are considered excellent habitat for fish, other aquatic life, and wildlife and are suitable for shellfish harvesting and for primary and secondary contact recreation (MassDEP 2018). Projects within the Centerville Harbor Region were most recently dredged between 2003 and 2014 and the material was placed along Dowses Beach, Long Beach, and Craigville Beach for nourishment. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 9 Table 3: Centerville Harbor Region Dredge History Project Area Project Depth (FT MLW) Dredged By Date Last Dredged Material Removed (CY) Material Type Centerville River Upper Reach, Spur, and Bumps River Channel -6, -4, -4 Town 2006 25,000 Sandy and Silty Centerville River Lower Reach Channel -7 Town 2003 40,700 Sandy East Bay Entrance Channel -6 Town 2013-2014 9,569 Sandy There is limited data available for the Centerville Harbor Region project areas. Sampling and testing of 20 sediment samples from the Centerville River channel performed between 1999 and 2000 documented that the material from 8 of the samples contained 15% or more silt and clay. The remaining samples contained between 86.34 and 98.44% sand and gravel. Sampling and testing of 20 sediment samples from East Bay in 2012 found the material throughout the waterway to be predominantly sand and gravel (93-98%). Based on a review of available data and communication with local officials NAE determined that a total of 5 oil spill incidents were reported to MA DEP within the vicinity of existing outfalls that could have resulted into a related discharge into East Bay, Centerville River and/or the Bumps River. There are 18 town documented outfalls that occur within the vicinity of the Centerville Harbor area: 2 outfalls are located along the waterfront of the Centerville River lower reach channel, 2 outfalls are located along the waterfront of the Centerville River spur channel, 2 outfalls are located along the waterfront of the Bumps River channel, and 1 outfall is located along a direct tributary to the Centerville River. Following this tier one review of the site characteristics and the available historical data, the Centerville Harbor region was given a low-moderate risk ranking. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 10 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 11 Three Bays: The Three Bays Region in Barnstable consists of a large and complex estuary system with multiple inlets and sub-embayment’s situated along the northern shore of Nantucket Sound. Cotuit Bay and West Bay each connect Nantucket Sound with North Bay. The Seapuit River connects Cotuit Bay and West Bay, and separates Grand Island and Dead Neck Island. North Bay is the smallest of the Three Bays and West Bay is formed largely by the enclosure of Little Island and Oyster Harbors to the north and west. Cotuit Bay includes an 8 foot deep (MLW), 0.6 mile long entrance channel; a 1.15 mile long embayment channel which varies from 7 to 11 feet in depth (MLW); a 2.5 and 4.5 foot deep (MLW) basin at the Cotuit Town Landing; and a 6 foot deep (MLW), 0.07 mile long channel in the vicinity of Hoopers Landing. North Bay is connected to Cotuit Bay by the 8 foot deep (MLW), 0.7 mile long “Narrows” channel; and to West Bay by the 6 foot deep (MLW), 0.5 mile long “Bay Street” channel. West Bay includes an 8 foot deep (MLW), 0.6 mile long outer entrance channel; an 11 foot deep (MLW), 0.7 long inner entrance channel; and an 8 foot deep (MLW), 0.1 mile long spur channel. The Cotuit Bay embayment channel and the West Bay spur channel are connected to each other by the 7 foot deep (MLW), 0.17 mile long Seapuit River channel. The Three Bay system supports a variety of water dependent uses that meet local recreational, transient and commercial boating needs. There are 5 public access boat ramps located within the Three Bays as well as several privately owned boat yards, marinas, and other marine service facilities. Land use along the waterfront is a mix of residential properties, small commercial developments, and two golf courses. Dead Neck Island consists of Oyster Harbor Beach and the Mass Audubon Sampsons Island Wildlife Sanctuary. Water quality in the Three Bays area is dictated by tidal exchange with Nantucket Sound to the south and freshwater input from the Marstons Mill River located upstream from North Bay. The Commonwealth of Massachusetts designates the waters of the Three Bays area as Class SA (314 CMR 4.06). Class SA waters are considered excellent habitat for fish, other aquatic life, and wildlife and are suitable for shellfish harvesting and for primary and secondary contact recreation (MassDEP 2018). Projects within the Three Bays Region were most recently dredged between 1940 and 2010 and the material was placed along Dead Neck Beach for beach nourishment: FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 12 Table 4: Three Bays Region Dredge History Project Area Project Depth (FT MLW) Dredged By Date Last Dredged Material Removed (CY) Material Type Cotuit Bay Entrance Channel -8 Three Bays Preservation 1998 15,850 Sandy Cotuit Embayment Channel -7, -8, - 9, -10 Three Bays Preservation 1998 15,850 Sandy Cotuit Embayment Channel -10 Three Bays Preservation 2002 No Data Sandy Cotuit Town Landing -2.5, - 4.5 Town 2010 850 Sandy Hoopers Landing basin -6 State 1940 No Data Sandy Seapuit River Channel -7 State 1955 No Data Sandy West Bay Entrance Channel -8 State 1981 No Data Sandy North Bay “Narrows” Channel -8 State 1971 No Data Sandy North Bay “Bay Street” Channel -6 State 1982 No Data Sandy Sediment sampling and testing performed by the Three Bays Preservation in 2009 documented the material in the entrance channel to Cotuit Bay as sand and gravel with less than 1% fine grained material. Sediment sampling and testing performed by the Three Bays Preservation in 2007 documented the material from the North Bay region to be predominately sand and gravel with less than 1% fine grained material. Based on a review of available data and communication with local officials NAE determined that there have been 14 documented fuel spills or incidents involving an unknown sheen reported to the National Response Center (NRC) and 15 oil spill incidents reported to MA DEP within Cotuit Bay, North Bay, and West Bay between 1996 and 2014. The Harbormaster’s office reported an oil spill in 2003 from Crosby’s Yacht Yard, located to the north of the Bridge Street Bridge in FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 13 North Bay. In 2008 a hazardous spill with reported elevated concentrations of benzene and aliphatic hydrocarbons occurred at 905 Main Street on the western side of Cotuit Bay. There are 18 town outfalls located throughout the three Bays Region: 6 outfalls are located along the waterfront in Cotuit Bay and 5 outfalls along the waterfront in West Bay. Following this tier one review of the site characteristics and the available historical data, the Three Bays region was given a low-moderate risk ranking. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 14 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 15 Prince Cove: Prince Cove is connected to North Bay and the Three Bays system by an entrance channel in the Mill River. Prince Cove includes a 6 foot deep (MLW), 0.8 miles long entrance channel, and a 6 foot deep (MLW) basin. The Prince Cove Marina facility is located at the entrance of the cove and has been owned and operated by the town since 2002. The marina provides public access to the cove as well as slips for approximately 36 vessels, with 100 moorings located within the cove directly seaward and to the south of the docks. A public boat ramp is located on the north side of the marina. Other land use along the waterfront is primarily private residences and docks. Water quality in the vicinity of Prince Cove is dictated by tidal exchange with the Nantucket Sound through the Three Bays system and freshwater input from the Marstons Mill River. The Commonwealth of Massachusetts designates the waters of the Three Bays area as Class SA (314 CMR 4.06). Class SA waters are considered excellent habitat for fish, other aquatic life, and wildlife and are suitable for shellfish harvesting and for primary and secondary contact recreation (MassDEP 2018). Prince Cove was last dredged in 1956 when approximately 12,750 CY of sandy material was removed from the 6 foot channel and basin. The record plans for this effort did not identify a disposal/reuse site for sediments or previous sampling records. Based on a review of available data and communication with local officials NAE determined that there has been 1 reported incident involving an oily sheen documented by the NRC in the vicinity of the Prince Cove Marina in 2009 and 1 incident involving an oily sheen reported to MA DEP in the vicinity of Prince Cove in 2002. There are 5 documented outfalls surrounding the Prince Cove area, none are located along the waterfront. Following this tier one review of the site characteristics and the available historical data, the Prince Cove region was given a low-moderate risk ranking. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 16 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 17 3. Sampling, Testing, and Analysis: NAE prepared a sampling and analysis plan (SAP) for the project on 8 April 2020. The SAP called for 57 sediment cores to be collected from all of the proposed dredge areas and 24 grab samples to be collected from the proposed beach placement areas. Sixty-eight core samples and 27 beach grab samples were collected in April and May of 2020. The additional cores were taken to better delineate silty areas identified in the field and the additional beach grabs were taken to ensure representative sampling of the placement sites. Core logs are provided in Appendix A and the beach grab sample grain size distributions are provided in Tables B1 and B2 in Appendix B. Dredge area grain size data is summarized by geographic region in the following sections. Barnstable Harbor: Two samples were taken from the Barnstable Harbor Entrance Channel, the grain size distribution and material description is shown in Table 5 (Figure 6). Sample BH-1 was composed of a light grey/tan medium- fine sand with only 1.1% fines while sample BH-2 had approximately 10% fines. The Sandy Neck Public Beach and Millway Beach placement sites were composed of fine-medium sand and medium sand respectively (Figure 7 and Appendix B). Table 5: Barnstable Harbor Grain Size % BH-1 BH-2 Total Gravel 0.1 U 0.1 U Coarse Sand 1.3 0.3 Medium Sand 40.7 3 Fine Sand 56.9 86.2 Total Fines 1.1 10.5 Description light grey/tan sand with trace silt dark grey silty sand FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 18 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 19 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 20 Centerville Harbor: Seventeen samples were taken from the five channels in Centerville Harbor (Figures 8 and 9). The grain size distributions and material descriptions are shown in Tables 6-7. The East Bay Entrance Channel, represented by samples CH-EB-1 and CH-EB-2, was composed of a light grey/tan medium-fine sand with less than 2% fines. The lower part of the Centerville Harbor Lower Reach Channel (CH-LR-1 to CH-LR-3) was composed of grey fine-medium sand with less than 7% fines and some shells. Samples CH- LR-4 and CH-BR-1 were composed of a black/dark grey medium fine sand with more silt at the top of each core. The Centerville Harbor Upper Reach Channel samples (CH-UR-1 to CH-UR-5) were composed mainly of black organic silt and silty sand as well as some coarser grained material at CH-UR-3. The Centerville Spur Channel was composed of a dark grey fine-medium sand with a layer of silt in the top ~1.5ft of core CH-S-2, which was vertically subsampled into sample CH-2-2A (upper 1.3ft) and CH-2-2B (bottom 1ft) (Appendix A). The Long Beach, Craigville Beach, and Covell’s Beach nourishment area grab samples were composed of fine-medium sand (Figure 10 and Appendix B). Table 6: Centerville Harbor East Bay Entrance, Lower Reach, Bumps River Grain Size % CH-EB-1 CH-EB-2 CH-LR-1A CH-LR-1 CH-LR-2 CH-LR-3 CH-LR-4 CH-BR-1 Total Gravel 0.7 0.1 U 3.1 10.2 2.5 1.2 2.5 0.1 U Coarse Sand 0.7 4.5 5.2 8.2 2.7 4.5 1.6 0.4 Medium Sand 21.8 43.8 56.5 42.2 42.2 48.2 33.2 22.7 Fine Sand 75.9 42.3 32.9 35.2 46.8 39.4 59.2 72.5 Total Fines 0.9 1.5 2.3 4.2 5.8 6.7 3.5 4.4 Description light grey/tan medium fine sand grey/tan coarse sand grey coarse sand dark grey mud mixed with sand light grey coarse sand w/ trace fines on top grey medium grain sand, some shell black dark grey mud then sand w/shell black dark grey mud mixed w/ sand and trace shell FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 21 Table 7: Centerville Harbor Upper Reach and Spur Channels Grain Size % CH-UR-1 CH-UR-2 CH-UR-3 CH-UR-4 CH-UR-5 CH-S-1 CH-S-2 CH-S-3 CH-S-2- A CH-S-2- B Total Gravel 0.1 U 0.1 U 0.1 U 0.6 0.6 0.1 0.1 U 29.1 1.2 Coarse Sand 0.8 7.1 7.5 3.1 2.6 1.5 0.3 7.8 1.8 Medium Sand 38.3 2.3 38.6 25.7 5.8 59.9 26.2 39.8 69.1 Fine Sand 43.6 45.3 18.7 47.7 4.2 36.5 65.7 22.2 26.9 Total Fines 10.5 45.3 1.4 22.9 86.8 2 7.8 1.1 1 Description grey, thin top layer of silt, grey sand w/some silt black mud, wood debris, trace sand brown sand w/ cobble, trace silt light to medium grey silty sand black mud med. grey med. sand, some fines dark grey peat/bla ck mud on top of sand grey/tan med. coarse sand brown tan mediu m to coarse sand FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 22 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 23 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 24 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 25 Three Bays Region: Forty-four samples were taken from the 10 dredge areas in the Three Bays Region. The grain size distributions and material descriptions are shown in Tables 8-14. The Cotuit Entrance Channel and the Embayment Channel (Figure 11), samples TBR-CB-1 and TBR-CB-2, was composed of fine- medium and medium-fine grey/brown sand. The Cotuit -10ft MLW Embayment Channel, represented by sample TBR-CB-3, was also composed of a fine-medium grey/tan sand. The Cotuit Embayment Channel -11 and -9 ft MLW sections (samples TBR-CB-4 to TBR-CB-8) were composed of a mixture of grey/tan to black medium fine sand with pockets of black silt in the upper layers of cores TBR-CB-5, 7 and 7A. Sample TBR-7A was vertically subsampled into sample TBR-7A-A (upper 1.3ft) and TBR-7A-B (bottom 1.8ft). The Cotuit Embayment -7 MLW Channel was composed of a dark grey fine-medium sand with little fines. The Seapuit River Channel (Figure 12, samples TBR-SR-1 to TBR-SR-6) was composed of a dark grey to tan fine and medium sand, with some fines in the upper portion of TBR-SR-6. The West Bay Outer Entrance Channel (Figure 13), represented by sample TBR- WB-1, was composed of dark brown medium sand and some gravel sized material, likely shell hash. The dredge interval from the West Bay Spur Channel, represented by sample TBR-WB-2, was composed of black organic silt. An additional sample was taken, TBR-WB-2A, which was composed of light gray sand. The West Bay Inner Entrance Channel (samples TBR-WB-3 to TBR-WB-6) was composed of dark grey and brown fine and medium sand with black silt concentrated at the top of cores TBR-WB-5 and 6 and almost 30% fines in sample TBR-WB-5A. The Bay Street Channel, samples TBR-NB-1 to TBR-NB-5, was composed of black organic silt and dark grey silt and sand. The North Bay Narrows Channel, samples TBR-NB-6 to TBR-NB-9, was composed of a grey/tan fine-medium sand (Figure 14). Two samples were taken from the Hoopers Town Landing dredge area (Figure 15). Sample TBR-HL-1 was stratified and two vertical subsamples were taken. TBR-HL-1-A was composed of black silt and sand from the top ~15 inches with grey/brown sand below (sample TBR-HL-1-B). Sample TBR-HL-2 was composed of black organic silt. The Cotuit Town Landing (Figure 16), represented by samples TBR-CTL-1 and TBR-CTL-2, was composed of a layer of black organic silt over fine sand. Subsamples were not taken from the separate layers and therefore the grain size distribution shown in Table 14 is not representative of the individual strata. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 26 The Cross Street Beach nourishment area samples were composed of medium and fine-medium sand. The Ropes Beach nourishment area samples were composed of fine-medium sand and the Dead Neck Beach nourishment area samples were composed of medium sand and sandy gravel (Figure 17 and Appendix B). Table 8: Cotuit Bay Entrance and Embayment Channels Grain Size % TBR-CB-1 TBR-CB-2 TRB-CB-3 TRB-CB-4 TRB-CB-5 TRB-CB-5A TRB-CB-6 Total Gravel 7.3 0.3 0.1 U 1.9 14.2 7.7 5.2 Coarse Sand 5.7 0.8 1.4 1.5 8.4 1.8 4.3 Medium Sand 46.3 25.8 67.8 46 24.3 49.3 38.7 Fine Sand 36.9 67.9 29.6 45.5 40.7 37.9 47.6 Total Fines 3.8 5.2 1.2 5.1 12.4 3.3 4.2 Description brown grey med. sand w/ some fines brown tan med. fine sand grey tan coarse sand grey tan coarse sand with some silt grey muddy sand w/ some shell grey med. Fine sand, some silt dark grey muddy sand, trace shell Table 9: Cotuit Bay Embayment Channel Grain Size % TRB CB-7 TBR-CB-7A TRB CB-8 TRB CB-9 TBR-CB- 7A-A TBR-CB- 7A-B Total Gravel 7 10.3 2.2 2.5 3.1 Coarse Sand 3.4 23.1 1.8 0.8 2.5 Medium Sand 36.7 22.6 22.1 8.5 57.3 Fine Sand 43.9 17.4 70.7 79.2 33.5 Total Fines 9 26.6 3.2 9 3.6 Description grey sand w/ mud and shell black mud tan med. fine sand tan med. fine sand dark grey mud mixed w/ sand FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 27 Table 10: Three Bays Region Seapuit River Channel Grain Size % TRB-SR-1 TRB-SR-2 TRB-SR-3 TRB-SR-4 TRB-SR-5 TRB-SR-6 Total Gravel 15.7 1.4 1 1.1 0.7 0.1 Coarse Sand 8 4.1 1.2 3.2 1.5 0.5 Medium Sand 46.1 50.1 43.7 45.9 50.3 36.5 Fine Sand 26.6 39.7 47.5 47.6 45.9 58.5 Total Fines 3.6 4.7 6.6 2.2 1.6 4.4 Description grey tan med. sand w/some shell light grey med. sand dark grey fine sand some shell grey/tan med. coarse sand tan med. sand grey/brown med. sand some silt Table 11: West Bay Outer and Inner Entrance and Spur Channels Grain Size % TRB-WB-1 TRB-WB-2 TRB-WB-2A TRB-WB-3 TRB-WB-4 TRB-WB-5 TBR-WB-5A TBR-WB-6 Total Gravel 33.9 7 0.1 3.9 24.6 4 0.6 6.8 Coarse Sand 13.3 2.2 0.1 U 6.9 4.8 3 2.4 2.4 Medium Sand 32.1 6.5 1.3 45.7 35 48 29.9 42 Fine Sand 19.7 79 96.2 39.3 32.9 36.6 39 39.2 Total Fines 1 5.3 2.4 4.2 2.7 8.4 28.1 9.6 Description dark brown coarse sand some mud and shell black silt/fines light grey fine sand and silt sand w/ some shell and fines coarse sand w/ some mud grey brown mostly sand and some mud black/grey mud and sand dark grey mud and sand FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 28 Table 12: Three Bays Region Bay Street Channel Grain Size % TBR- NB-1 TBR- NB-1A TBR- NB-2 TBR- NB-2A TBR- NB-3 TBR- NB-3A TBR- NB-4 TBR- NB-4A TBR- NB-5 Total Gravel 11.6 7.4 2.7 0.9 2.4 4 9.8 8.6 0.1 U Coarse Sand 11 5.5 5 4.2 4.7 4 5.5 5 1.3 Medium Sand 39.3 11.9 19.7 44.1 53.6 48.5 53.1 47.3 4.4 Fine Sand 20.4 13.5 34 44.8 32.5 35.8 28.1 29 4.2 Total Fines 17.7 61.7 38.6 6 6.8 7.7 3.5 10.1 90.1 Description dark grey muddy coarse sand w/ some cobble grey mud, clay shell and some fine sand thick black clay grey mud mixed with coarse sand black silty muddy sand black mud and sand w/ shell medium to coarse sand with trace shell black grey mud, some shell black mud Table 13: Three Bays Region North Bay Narrows Grain Size % TBR-NB-6 TBR-NB-7 TBR-NB-8 TBR-NB-9 Total Gravel 8.6 0.6 0.7 6.3 Coarse Sand 7.7 2.1 4 8.4 Medium Sand 51.9 37.5 53.8 50 Fine Sand 28.8 57.8 40.5 33.1 Total Fines 3 2 1 2.2 Description grey brown coarse sand w/ silt grey/tan med. coarse sand grey/tan med. coarse sand, trace shell grey/tan med. coarse sand, trace shell Table 14: Hoopers Landing and Cotuit Town Landing Grain Size % TBR-HL-1 TBR-HL-2 TBR-CTL- 1 TBR-CTL-2 TBR-HL- 1-A TBR-HL- 1-B Total Gravel 1.4 3.8 3.8 1.4 1 Coarse Sand 2.3 4.4 5.7 2.8 3.3 Medium Sand 33.6 50 11.5 9.9 17.7 Fine Sand 35.2 36.2 7.4 68.1 70.6 Total Fines 27.5 5.6 71.6 17.8 7.4 Description thick black mud and clay tan coarse sand some cobble thick black mud and clay black mud, fines black mud, fine sand FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 29 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 30 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 31 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 32 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 33 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 34 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 35 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 36 Prince Cove: Eight samples were taken from the two dredge areas in Prince Cove (Figure 18). The grain size distributions and material descriptions are shown in Table 15. The Prince Cove Entrance Channel, samples PC-C-1 to PC-C-5, was composed of dark grey silty sand, with the fines concentrated in the upper part of the cores. The dredge interval from sample PC-C-5 consisted of a layer of black organic silt. The Prince Cove Marina Basin was composed of dark grey/back silty sand and black organic silt at stations PC-B-1 and PC-B-3. While sample PC-B- 2 was composed of tan medium sand. Table 15: Prince Cove Entrance Channel and Marina Basin Grain Size % PC-C-1 PC-C-2 PC-C-3 PC-C-4 PC-C-5 PC-B-1 PC-B-2 PC-B-3 Total Gravel 10 0.1 U 32.9 10.1 1.3 11.8 6.6 2.7 Coarse Sand 3.9 3.6 8.9 4.1 1.7 2.3 3.8 19.1 Medium Sand 41.8 58 35.8 35 25.8 20.9 57.7 18.7 Fine Sand 40.9 37.4 20.8 48.4 67.2 57.3 30.8 7.8 Total Fines 3.4 1 1.6 2.4 4 7.7 1.1 51.7 Description brown grey mud, sand, shells dark grey sand with some mud and shell dark grey mud, sand, small cobble dark grey mud, sand, shell black mud dark grey mud, clay w/ shell tan coarse sand w/ small cobble black mud FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 37 FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 38 4. Suitability Determination: The disposal of sediments at the proposed placement areas is regulated under Section 404 of the Clean Water Act. Under §230.60, General Evaluation of Dredged or Fill Material, further testing of the dredged material is not necessary if the material is not considered a carrier of contaminants. According to §230.60(a) the proposed dredged material is most likely free from pollutants where it is composed primarily of sand from a high energy environment and the extraction site meets the evaluation factors under §230.60(b). These factors include, but are not limited to, an examination of potential routes of contamination, pertinent test results, and a review of spill records. Barnstable Harbor Given the high energy environment and consistent history of sandy material supported by previous and recent testing results, the Barnstable Harbor Outer Entrance Channel is considered suitable for 10-year beach nourishment (Figure 6). Centerville Harbor Due to the high energy environment and consistent history of sandy material supported by previous and recent testing results, the East Bay Entrance Channel is considered suitable for 10-year beach nourishment (Figure 8). The Centerville River Lower Reach Channel is suitable for one-time beach placement (Figure 8). Given the potential for fine grained material from adjacent upstream channels to accumulate in the future the Centerville River Lower Reach Channel is not suitable for 10-year beach nourishment. The remainder of the channels in Centerville Harbor were composed of a mix of sand and silt and based on the core descriptions, photos, and grain size, are not suitable for beach placement and require additional testing to evaluate disposal alternatives (Table 16, Figures 8 and 9). Three Bays Region Of the channels and basins in the Three Bays Region, the Cotuit Entrance Channel, the Cotuit –10 MLW Embayment Channel (Figure 11), and West Bay Outer Entrance Channel (Figure 13), are suitable for 10-year beach nourishment due to their high-energy depositional environment and recent testing results. The Cotuit Embayment -7 ft MLW Channel and the portion of the -9 ft MLW Cotuit Embayment Channel represented by sample TBR-CB-8 (Figure 11), the Seapuit River Channel (Figure 12), and the North Bay Narrows Channel (Figure 14) are suitable for one-time beach placement. These channels are not suitable for 10-year beach nourishment due to a lack of previous testing data and the potential for finer grained material to accumulate in these depositional environments. The remaining channels in the Three Bays region were composed FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 39 of a mix of sand and silt and based on the core descriptions, photos, and grain size, are not suitable for beach placement and require additional testing to evaluate disposal alternatives (Table 16, Figures 14, 15, and 16). Prince Cove The Prince Cove Entrance Channel and Marina Basin were composed of a mixture of sand and silt and based on the core descriptions, photos, and grain size, are not suitable for beach placement (Figure 18). This area is not in a high energy environment and therefore does meet the exclusionary criteria of §230.60(a). Based on the weight of evidence including the conceptual site model, low- moderate project risk ranking, project footprints, core logs, and the grain size results for these sediments, according to the testing and evaluation requirements set forth in Section 404 of the CWA, the sediments to be dredged from the East Bay Entrance Channel, Cotuit Entrance Channel, Cotuit -10 MLW Embayment Channel, West Bay Outer Entrance Channel, and the Barnstable Harbor Entrance Channel are considered suitable for 10-year beach nourishment. The Centerville Harbor Lower Reach Channel, the Cotuit Embayment -7 MLW Channel, the portion of the -9 ft MLW Cotuit Embayment Channel represented by sample TBR-CB-8 , the Seapuit River Channel, and the North Bay Narrows Channel are suitable for one-time beach placement. All other proposed dredge areas are unsuitable for the beach nourishment program. Other beneficial re- use or disposal options, including nearshore placement and open water disposal, may be available but require additional sampling and testing to be evaluated. This suitability determination was coordinated with EPA Region 1 and MADEP. MADEP concurred with the determination and EPA Region 1 conducted an individual evaluation of the project and documented their findings in a separate memo. FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 40 Table 16: Suitability Summary Channel Decision Volume CY (with OD) Placement Area Barnstable Harbor Entrance Channel Barnstable Harbor Entrance Channel 10-year beach nourishment 1,305 Millway Beach, Sandy Neck Public Beach Centerville Harbor East Bay Entrance Channel 10-year beach nourishment 149 Long Beach, Craigville Beach, Covell's Beach Centerville River Lower Reach Channel suitable for one time beach placement 3,756 Centerville River Upper Reach Channel not suitable 12,112 N/A Centerville River Spur Channel not suitable 2,518 N/A Bumps River Channel not suitable 217 N/A Three Bays Region Cotuit Entrance Channel 10-year beach nourishment 12,678 Dead Neck, Cross St. (Riley's) Beach, Ropes Beach Cotuit Embayment Channel (-10 MLW) 10-year beach nourishment 5,471 West Bay Outer Entrance Channel 10-year beach nourishment 800 Cotuit Embayment Channel (-7 MLW) suitable for one time beach placement 2,234 Cotuit Embayment Channel (-9 MW) (area represented by sample TBR-CB-8) suitable for one time beach placement 1,696 Seaput River Channel suitable for one time beach placement 8,042 North Bay Narrows Channel suitable for one time beach placement 8,714 Cotuit Embayment Channel (-9 MLW) not suitable 10,367 N/A Cotuit Embayment Channel (-11 MLW) not suitable 7,386 N/A FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 41 Channel Decision Volume CY (with OD) Placement Area Three Bays Region Hoopers landing not suitable 4,977 N/A Conduit Town Landing not suitable 21 N/A West Bay Spur Channel not suitable 775 N/A West Bay Inner Entrance Channel not suitable 62,100 N/A Bay Street Channel not suitable 30,507 N/A Prince Cove Prince Cove Entrance Channel not suitable 9,014 N/A Prince Cove Marina Basin not suitable 3,734 _________________________________ _________________________________ Sarah Turner Geologist Environmental Resources and Marine Operations Section USACE-New England District Joseph B. Mackay Chief Environmental Resources and Marine Operations Section USACE-New England District FINAL Suitability Determination for the Barnstable, MA 10-Year Comprehensive Dredge & Beach Nourishment Program, CENAE-2015-01632 42 5. References: EPA/USACE 2004. Regional Implementation Manual for the Evaluation of Dredged Material Proposed for Disposal in New England Waters. U.S. EPA Region 1, Boston, MA/U.S. Army Corps of Engineers, New England District, Concord, MA. USACE 2018. Dredged Material Evaluation and Disposal Procedures, User Manual. Dredged Material Management Program, U.S. Army Corps of Engineers, Seattle District