B09_amd_5_attach_24_GOGA_AlcatrazWharfPier_NMFSLetter_20210916_FINAL_LEJ_0005.pdf

United States Department of the Interior

NATIONAL PARK SERVICE

Golden Gate National Recreation Area, Interior Region 10

Building 201, Fort Mason San Francisco, CA 94123-0022

IN REPLY REFER TO:

1.A.2. (GOGA-NRMR)

INTERIOR REGION 10 • CALIFORNIA−GREAT BASIN

CALIFORNIA*, NEVADA*, OREGON*

*PARTIAL

September 21, 2021

Barry A. Thom Regional Administrator National Marine Fisheries Service, West Coast Region c/o Gary Stern North Central Coast Regional Office 777 Sonoma Avenue, Room 325 Santa Rosa, CA 95404-4731

Re: Request for concurrence on a not likely to adversely affect determination for six Federally listed species associated with the Alcatraz Wharf Stabilization project (NMFS 151422-SWR-

01-SR-335)

Dear Mr. Thom:

The Golden Gate National Recreation Area (GGNRA) proposes to stabilize the concrete fixed wharf and timber finger pier on the southeast side of Alcatraz Island, located in central San Francisco Bay (Figure 1). We have previously consulted on this project in 2001 and received a concurrence of a not likely to adversely affect determination to listed species covered under the ESA as well as your agency’s conclusion that the 2001 proposed project actions would not take marine mammals (pursuant to the Marine Mammal Protection Act) or require additional Essential Fish Habitat Conservation Recommendations under the Magnuson Stevens Fisheries Conservation and Management Act (MSFCMA) (NMFS letter dated June 26, 2001, NMFS

151422-SWR-01-SR-335).

Since the original consultation in 2001, there have been substantive changes in the project scope including the addition of repairs to the timber finger pier that adjoins the concrete wharf on the north. Also, new information about the distribution of listed species and the listing of North American green sturgeon, southern distinct population segment in 2006, have occurred after the original consultation. Therefore, we wish to re-initiate consultation on this project and provide an updated project description that has included actions to avoid impacts to listed species and marine mammals. We appreciate the efforts of your staff (Sara Azat) during the development of the project description.

We have reviewed our proposed actions for the following listed species and designated critical habitat:

• North American green sturgeon southern distinct population segment (Acipenser medirostris) (threatened, critical habitat)

• Sacramento River winter run chinook (Oncorhynchus tshawytscha) (endangered, critical habitat)

• Central Valley spring-run chinook salmon (O. tshawytscha) (threatened, critical habitat)

• Central California Coast steelhead (O. mykiss) (threatened, critical habitat)

• Central Valley steelhead (O. mykiss) (threatened, critical habitat)

• Humpback whale-Mexico/Central America distinct population segments (Megaptera novaeangliae) (threatened Mexico population; endangered Central America population, critical habitat but outside project boundaries)

PROPOSED ACTION

The National Park Service proposes to conduct work to stabilize and seismically upgrade the concrete wharf and timber dock (finger pier) at Alcatraz Island, located in central San Francisco Bay, California (Figures 1-2). The original wharf was built in 1854, was reinforced with steel in 1907, and replaced with concrete in 1939. The wharf and pier repairs are proposed to mitigate deterioration and damage of the existing supporting structures, and to meet requirements for seismic stability. The steel gangway, attached to the finger pier, is used occasionally to offload crew and supplies from small boats and water taxis. This gangway was damaged in a storm event and would be replaced. The proposed work includes repair and/or replacement of piles and overwater structure on the wharf, the finger pier and gangway described below and summarized in Table 1.

Wharf Repairs And Seismic Upgrade. The proposed work includes pile repair and replacement, wharf deck repair and the installation of 1 concrete pilaster. Up to 221 piles are proposed for replacement or repair to support the wharf structure. The pile types included for replacement include up to 5 16-inch diameter steel pipe piles, and 10 30-inch diameter steel piles. Additional pile repair would occur on approximately 206 16-inch diameter concrete piles not slated for replacement. The 16-inch and 30-inch replacement piles would be installed using a technique where steel pile casings (hollow piles) are first installed to prevent drill spoils from entering the water, and a rotary drill is used to drive the pile into the ground with rotation, or sockets are drilled to depth. A casing is driven through the overburden layer (a mixture of silt, sediment and cobble) to bedrock (approximately two to five feet below the top of the silt/sediment layer). The casing is installed approximately 6-inches into the bedrock. An auger is then used to drill up to 15 feet into bedrock. Piles are then placed inside the casing and grouted into the socket. After the pile is placed and grouted, the casing is removed with the aid of a vibratory hammer. The installation of the 16-inch and 30-inch diameter steel casings would occur using an impact or vibratory hammer operated from the wharf deck. If a vibratory hammer is used to install the casing through the overburden, an impact hammer would likely need to be used to set the casing into the bedrock to create a seal. One casing could be installed per day and impact pile driving could occur for 20 to 30 minutes per casing. All steel casings would be installed at elevations ranging from +1 to -7.5 feet mean lower low water (MLLW). Drilling for the installation of the 30-inch piles would occur for approximately five hours per pile, and no more than two 30-inch diameter steel piles would be placed each day. Drilling for the installation of 16-inch diameter piles, could occur for up to one hour per pile with two piles being installed per day.

A 2-foot by 2-foot pilaster is also proposed to be installed against the existing seawall. This pilaster is to be installed at a location where bedrock protrudes from the sea floor at an elevation higher than Mean Higher High Water (MHHW). A 2-foot by 2-foot by 2-foot deep socket will need to be cut into the rock mass for the pilaster installation. The socket will be cut with the aid of jackhammers and hand tools. All work for this retrofit item will happen in the dry.

Repair of the 16-inch concrete piles would involve installing a protective fiberglass jacket forming system around the existing pile. The repair work includes removing existing steel jacket shells on the piles with an oxyacetylene torch or by mechanical means, and subsequent removal of any damaged concrete using a jackhammer. Rebar would be cleaned with a wire brush and replaced if section loss due to corrosion exceeds a threshold. Replacement rebar would be doweled into existing concrete using a rotary drill and/or clamped to existing good rebar with the aid of a handheld impact driver. A fiberglass jacket would then be installed around the pile, covering the length of the pile from beam soffit to the top of competent rock, to 1 foot below mudline or to an elevation of -4 ft MLLW whichever occurs first. Substrate would be shoveled away from the piling at the mudline and then replaced once the jacket is secured. A multi-purpose marine grade epoxy grout would then be used to fill the void space inside the jacket to complete the repair. Fiberglass jacketing work would be completed by hand, using divers accessing the work area by boat.

The proposed work also includes repairs to approximately 3,700 square feet of concrete deck (slab) and 2,500 linear feet (5,000 square feet) of beam support. The repair work includes removal of any damaged concrete and supporting rebar and replacement by splicing in new rebar and setting new concrete slab. All slab and beam work will occur above water. A jackhammer will be used to remove the damaged concrete. Existing rebar will be cleaned and rebar with section loss exceeding a threshold of 50% will be removed and supplemental rebar will be added.

Rebar that is to be removed will be cut with the aid of a cutoff wheel or oxyacetylene torch.

Replacement and supplemental rebar would be doweled into existing concrete using a rotary drill and/or clamped to existing good rebar with the aid of a handheld impact driver. A jackhammer may be used during the entirety of the day and multiple hammers may be used at once.

Following removal of the damaged concrete and replacement of the damaged rebar, the concrete section will be repaired.

There are two options for repairing the beam and slab concrete. One option would involve the construction and installation of form work followed by a concrete casting and the other would use shotcrete. If shotcrete is used, scaffolding and suitable sheeting shall be installed under all areas where shotcrete is being placed. The sheeting shall extend out far enough to capture all reasonable concrete rebound or overspray and prevent concrete from entering the water.

Shotcrete may be preferable due to a lower cost of placement. The proposed work, including the pile repair and replacement, is expected to take from 22 months up to three years to complete.

Finger Pier Repair and Gangway Replacement. The proposed work includes the replacement of timber piles with a combination of timber and steel piles with an HDPE sleeve and replacement of a steel gangway. Approximately nine 12-14-inch diameter timber piles, and five 10.75-inch diameter steel pipe piles, with HDPE sleeves, are proposed as replacements for existing deteriorated timber piles. Existing damaged piles would be removed using a vibratory hammer where possible. Stubs broken off below the mudline would be left in place. Piles would be installed using an impact hammer, and hammer operation is estimated to be 20 minutes per pile.

Pile cross bracing would be replaced with the use of hand tools. The current plan does not anticipate any repairs to the finger pier deck or stringers. An ancillary quantity of decking and deck substructure replacement may be required to facilitate the pile replacements. All repairs to deck elements would be conducted from the deck surface (out of the water) utilizing hand tools.

The existing gangway consists of a steel frame with wood decking and is proposed to be removed entirely and replaced with a prefabricated steel frame and wooden deck landing brought in by barge and lifted into place using a crane. The replacement gangway would not result in change of light transmittance. The total area of both the finger pier and gangway is approximately 1,600 sq. ft. Water depth under the gangway is approximately 5 feet MLLW.

Water depth at the finger pier varies from approximately 12.5 to 30 feet MLLW. The proposed work is expected to take approximately three to five weeks, and would occur as part of the larger Wharf Repairs project.

The NPS proposes the following measures to avoid and/or minimize the impacts of this project:

• All in-water work shall be conducted during the in-water work window from June 1 through November 30.

• Noise mitigation systems would be used. A wood cushion block would be used during impact pile driving. Alternate hammer types to reduce underwater sound pressure would be used first (e.g., vibratory hammers) before using impact hammers where possible to minimize impacts to wildlife. If an impact hammer is used, bubble curtains shall be used to minimize sound impacts.

• A maximum of one pile casing would be installed per day. No more than 200 blows a day would occur during casing installation.

• Pile-driving shall commence with a soft start procedure (ramping up) to alert nearby wildlife, allowing them to move out of the area prior to construction activities. For impact pile driving, contractors shall be required to provide an initial set of strikes from the hammer at reduced percent energy, each strike followed by no less than a 30-second waiting period. This procedure shall be conducted a total of two times before impact pile driving begins. Where a vibratory hammer is used, contractors shall initiate sound from vibratory hammers for 15 seconds at reduced energy followed by a 1-minute waiting period. This procedure shall be repeated two additional times before full energy may be achieved.

• No debris shall be allowed to enter the water; any accidental release of debris shall be removed from the water immediately.

• Fiberglass jackets shall be installed, sealed, and extend above high tide to allow grout placement to minimize the risk of grout contacting surface waters. The two ends of the jackets shall be sealed, and air will be vented with ports. During fiberglass jacket installation, the contractor shall have a diver in place to make sure that forced grout is not being released into the Bay.

• Installation and application of epoxy, resin, or cementitious grout/fill will be conducted when predicted weather and ocean conditions allow effective control and full containment and shall remain dry until cured, in order to prevent any leaching of uncured treatment materials into coastal waters. Jackets shall be installed during low tide to the extent feasible. Work shall cease during inclement weather (large waves or heavy rain)

• Full time biological monitoring, establishment of a 500 meter “exclusion zone” for marine mammals shall be used during the in-water work window (June 1-November 30).

The buffer area shall be surveyed starting 30 minutes before percussive, or loud in-water work, during this work, and continuing for 30 minutes after this work is halted. If marine mammals or special status species are observed, percussive/loud work would be halted until these animals are no longer observed within and have moved from within the buffer zone.

• ACZA timber piles shall be urea coated to mitigate potential leaching of copper into the waterways.

• Worker Environmental Awareness Training, required for all project personnel (including those on project-related watercraft), shall be conducted by an NPS approved biologist before the start of work.

STATUS OF THE LISTED FISH SPECIES WITHIN PROJECT AREA

There is minimal data available regarding the current status of listed salmonids adjacent to Alcatraz Island. We assume that all listed salmonids within the project area are present as migrating juveniles or adults. A study on the movement of non-listed fall-run chinook smolts in the San Francisco Estuary had detections of smolts on an antenna array in waters off of Alcatraz

Island but the study noted that the smolts transited the estuary rapidly in 2 to 4 days (Hearn et al 2013). A similar use pattern would be expected of the listed salmonid species.

There is minimal specific data regarding the distribution and abundance of sturgeon in the waters off Alcatraz Island. San Francisco Bay provides important rearing and migratory habitat for juvenile Southern DPS green sturgeon prior to entering marine waters (NOAA 2009). It also provides an important migratory corridor for subadults and adults from the ocean to and from the bays and Sacramento River system (NOAA 2009). A recent telemetry survey of green sturgeon movements in the San Francisco Estuary found tagged green sturgeon using the waters off of Alcatraz, but the majority of the detections (95%) for all stations were at water depths greater than 5 meters (Chapman et al., 2019). Peak occurrence at the Alcatraz station was in late winter-early spring and lower occurrences through early summer (Chapman et al., 2019).

ESSENTIAL FISH HABITAT (EFH)

The project site is located within an area identified as EFH for various fish life stages managed under the Pacific Coast Salmon Fishery Management Plan, the Pacific Groundfish Fishery Management Plan, and the Coastal Pelagic Fishery Management Plan. The San Francisco Bay has also been identified as a Habitat Area of Particular Concern within the Pacific Groundfish Fishery Management Plan.

IMPACT ASSESSMENT AND EFFECTS DETERMINATION

We have determined that our proposed actions, including avoidance measures, may affect but are not likely to adversely affect the aforementioned listed fish species or adversely modify critical habitat. We base this determination on the following: (1) the in-water work window corresponds with the low likelihood of listed salmonids and green sturgeon being present in the project area during in-water construction; (2) implementation of conservation measures (e.g., noise mitigation measures) to limit construction-related impacts to temporary and localized increases in underwater noise and suspended sediment and turbidity during in-water construction; and (3) the footprint of the proposed actions are small (0.009 acres of fill) and located in a disturbed intertidal/subtidal environment. We have attached sound calculations for the proposed pile driving activities and pile driving checklist which have previously been forwarded to your staff (Attachments 1-2).

Please provide a letter of concurrence if you agree with our determination or request initiation of formal consultation.

If you have any questions regarding this project please feel free to contact Project Manager, Jason Hagin at jason_hagin@nps, Aquatic Ecologist Darren Fong at darren_fong@nps.gov or Wildlife Ecologist Bill Merkle at bill_merkle@nps.gov.

Sincerely, Laura E. Joss General Superintendent

From Moffatt&Nichol (2021) USACOE nationwide permit application

From Moffatt&Nichol (2021) USACOE nationwide permit application

INTERIOR REGION 10 • CALIFORNIA−GREAT BASIN

Table 1: Summary of pile driving activities for Alcatraz fixed wharf and finger pier repair

*PARTIAL

LITERATURE CITED

Chapman, E.D., E.A. Miller, G.P. Singer, A.R. Hearn, M.J. Thomas, W.N. Brostoff, P. E.

LaCivita, and A.P. Klimley. 2019. Spatiotemporal occurrence of green sturgeon at dredging and placement sites in the San Francisco estuary. Environ. Biol. Fish. 102: 27–

40. https://doi.org/10.1007/s10641-018-0837-9

Hearn, A.R., E.D. Chapman, G.P. Singer, W.N. Brostoff, P.E. LaCivita, and A.P. Klimley.

2013. Movement of out-migrating late-fall run Chinook salmon (Oncorhynchus tshawytscha) smolts through the San Francisco Bay Estuary. Environ. Biol. Fish. 97:

851–863. https://doi.org/10.1007/s10641-013-0184-9

National Oceanic and Atmospheric Administration. October 9, 2009. Endangered and threatened wildlife and plants: final rulemaking to designate critical habitat for the threatened southern distinct population segment of North American green sturgeon; final rule. Federal Register. 74 (195):52300-52351.

ATTACHMENT 1

ATTACHMENT 2

Proposed Action