Memorandum 40600-HS-MEM-55036 Revision 0 Date: 26 July 2018 Subject: Eelgrass and Macroalgae Presence/Absence Preliminary Surveys BHP Proposed Grays Harbor Potash Export Facility A17.0202.00 Task 400 INTRODUCTION The proposed BHP Billiton Canada Inc. (BHP) Grays Harbor Export Facility includes potential in-water impacts associated with the construction of the shiploader facility, conveyance, and dredging needed to accommodate the ships at berth. Preliminary surveys for presence/absence of eelgrass and macroalgae were completed at low tide (May 2017 and February 2018) and via video survey in conjunction with the dredged material sediment sampling site visit in February 2018. The U.S. Army Corps of Engineers (USACE) Components of a Complete Eelgrass Delineation Report (9 January 2018) states, In areas where there is a reasonable expectation for suitable eelgrass habitat (e.g., appropriate depth and substrate) to occur in the project vicinity, a Preliminary Survey may be used to support a statement regarding the absence of eelgrass at the project site. The report further states that an acceptable methodology for completing such a survey would be a series of photographs of the substrate taken while walking or wading at low tide. We have included photographs of the project area at low tide and completed an in-water video absence/presence survey to provide coverage for the deeper portions of the project area that are not visible during a walking or wading survey. These tideflat and in-water surveys meet the guidelines for acceptable preliminary studies to evaluate the presence/absence of eelgrass and macroalgae at a site. Additionally, divers that were assisting the dredged material sediment sampling also provided their observations of the mudline in the dredge prism area. Grays Harbor Kelp and Eelgrass Beds A review of the Washington State Coastal Atlas Map (Washington State Department of Ecology [Ecology] 2017) indicates that patchy eelgrass beds were mapped by the Washington Department of Natural Resources (DNR) Shorezone Inventory between 1994 and 2000 (see Figure 1). These beds were identified by reviewing aerial photos obtained at low tides and are located in Bowerman Basin to the west and to the south across the navigation channel. Eelgrass beds were not identified in the project area as shown on Figure 1.
Eelgrass and Macroalgae Presence/Absence Preliminary Surveys BHP Proposed Grays Harbor Potash Export Facility, A17.0202.00 July 2018 Page 2 Project Site Figure 1. Washington Coastal Atlas Map (Source: DNR 2001). The DNR Shorezone Inventory data was completed in 2000 and has not been updated within Grays Harbor. There were no other public data sources identified that contain more recent documentation of eelgrass/macroalgae presence in the project area. LOW TIDE OBSERVATIONS BergerABAM completed a baseline habitat survey of the site in May 2017 at low tide (-0.5 feet mean lower low water [MLLW]) to verify the presence or absence of eelgrass and macroalgae within the project area. MLLW is approximately 500 feet south of the shoreline. Eelgrass commonly occurs at depths ranging from 0 feet to approximately -30 feet MLLW but is dependent on substrate conditions and bathymetry. Figure 2, attached, depicts site bathymetry (Berglund and Schmidt and Associates, December 2017) with respect to the existing Port of Grays Harbor Terminal 3 to provide context for the conditions observed during the baseline habitat survey. Preliminary eelgrass and macroalgae presence/absence surveys were conducted at a tide level of approximately -0.5 foot MLLW by foot in May 2017. Kelp and eelgrass were not present at the time of this site visit. Other marine vegetation was very sparse in the tideflat area. Photographs were taken during the tideflat survey conducted as part of the baseline habitat survey site visit on 15 May 2017 (Photos A through G, BergerABAM). 2
Eelgrass and Macroalgae Presence/Absence Preliminary Surveys BHP Proposed Grays Harbor Potash Export Facility, A17.0202.00 July 2018 Page 3 The tideflat within the project area was also observed to approximately 0 feet MLLW during the sediment sampling event completed in February 2018. Eelgrass or macroalgae were not observed to be present on the visible portion of the tideflat at that time (Photos H through M). Divers assisting with the sampling efforts reported that the mudline in the survey area is generally featureless, silty-sand bottom with some scattered gravel and shell debris, sparsely distributed unidentified clams, and no eelgrass or macroalgae. A non-quantitative presence/absence video survey was also completed within the proposed dredge prism in conjunction with the sediment characterization event in February 2018 (Research Support Services, Inc. [RSS] February 2018). The video survey was completed using a GPS-enabled underwater camera lowered to mudline. VIDEO SURVEY The video was completed in transects across the dredge prism area (Figure 2). The video survey covered a fairly steep slope (approximately xh: xv) between approximately -2 and -15 feet MLLW, from the pier west to approximately 1,000 feet from the pier (Figure 2). The video survey images confirm the diver observations. Stills from the survey are included with this memorandum as Photos N through S. The underwater mudline conditions are similar to the conditions of the tideflat exposed at low tide between 0 and +1 foot MLLW. Visibility and current conditions made the survey difficult, but RSS concluded that eelgrass and kelp were not observed during the presence/absence video survey. It is the opinion of the surveyor that, due to the high current, low light transmission, and storm exposure at this site, eelgrass likely is not present at this location during the growing season. The full video and associated table of coordinates can be provided upon request. CONCLUSION These observations indicate that there are no eelgrass or kelp beds present within the project area during two distinct periods (May and February). There is a low potential that eelgrass or kelp beds would be present during the growing season based on the results of the preliminary surveys, the high current, low light transmission, and storm exposure at this site. Attachments 3
Eelgrass and Macroalgae Presence/Absence Preliminary Surveys BHP Proposed Grays Harbor Potash Export Facility, A17.0202.00 July 2018 Page 4 REFERENCES Berglund, Schmidt and Associates, Inc. December 2017. Bathymetric Survey of the BHP Grays Harbor site. Research Support Services, Inc. February 2018. Sea All eelgrass and macroalgae video survey of the BHP Grays Harbor site. Washington Department of Ecology. 2017. Washington Coastal Atlas mapping. https://fortress.wa.gov/ecy/coastalatlas/tools/map.aspx. Last accessed 27 November 2017. Washington Department of Natural Resources. 2001. Washington State Shorezone Inventory. Aquatic Resources Division, Nearshore Habitat Program. Olympia, WA. 4
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Eelgrass and Macroalgae Presence/Absence Preliminary Surveys BHP Proposed Grays Harbor Potash Export Facility Photographs
PHOTOGRAPHS A- G 15 May 2017 Site Visit (BergerABAM) Tideflat Walking Survey at a tide of approximately -0.5 foot MLLW Photo A. Facing south. Photo B. Example of marine plants present in small areas along tideflat.
Photo C. Facing south. Photo D. Facing toward Port of Grays Harbor Terminal 3 trestle. 8
Photo E. Facing south southeast toward Terminal 3. Photo F. Tideflat facing west southwest from near Terminal 3 trestle. 9
Photo G. Saltmarsh vegetation near shoreline. View from east side of existing terminal looking to the east. 10
PHOTOGRAPHS H through M 26 February 2018 (BergerABAM 2018) From Terminal 3 Pier during sediment sampling visit at Tide Level = 0 feet MLLW. Photo H. From Port of Grays Harbor Terminal 3 Pier, facing south. Photo I. From Port of Grays Harbor Terminal 3 Pier, facing south. 11
Photo J - From Port of Grays Harbor Terminal 3 Pier, facing southwest. Photo K. From Port of Grays Harbor Terminal 3 Pier, facing west-northwest. 12
Photo L - From Port of Grays Harbor Terminal 3 Pier, facing west-northwest Photo M. From Port of Grays Harbor Terminal 3 Pier, facing west. 13
PHOTOGRAPHS N through S 27 February 2018 (Research Support Services, Inc.) From Presence/Absence Video Survey The preliminary eelgrass and macroalgae presence/absence video survey was completed within the proposed dredge prism area during the dredge material characterization sampling event completed for the project in February 2018. The following are stills created from the video survey that were selected based on the relative clarity of the images. The coordinates where each photo was captured are shown on the photos. Photo N. Mudline. Photo O. Mudline. 14
Photo P. Mudline. Photo Q. Mudline. 15
Photo R - Mudline Photo S - Mudline 16