Amendment_0004_10_May_2019.pdf

1. CONTRACT ID CODE PAGE OF PAGES

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT 1 3

2. AMENDMENT/MODIFICATION NO. 3. EFFECTIVE DATE 4. REQUISITION/PURCHASE REQ. NO. 5. PROJECT NO. (If applicable)

0004 May 10,2019 647873

6. ISSUED BY CODE 7. ADMINISTERED BY (If other than Item 6) CODE Contracting Officer USCG CEU Oakland 1301 Clay Street 7th Floor, Suite 700N Oakland, CA 94612-5203

Same as Block 6

8. NAME AND ADRESS OF CONTRACTOR (no., street, county, State and ZIP Code) √ 9.A AMENDMENT OF SOLICITATION NO.

ALL PROSPECTIVE BIDDERS

X 70Z08819BPQQ10600

9B. DATE (SEE ITEM 11)

April 11, 2019

10A. MODIFICATION OF CONTRACT/ORDER

NO.

10B. DATED (SEE ITEM 13)

CODE FACILITY CODE

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offers is extended, is not extended. Offers must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended, by one of the following methods: (a) By completing Items 8 and 15, and returning 1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the Offer submitted: or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEGEMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS,

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE CONTRACT/.ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation data, etc) SET FORTH IN ITEM 14, PURSUANT TO AUTHORITY OF FAR 43.103(b).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority).

E. IMPORTANT: Contractor is not, is required to sign this document and return 1 copy to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

The purpose of this amendment is to provide responses to questions from prospective bidders, revise response to QUESTION 0008 provided in amendment 0003, revise the Schedule of Prices and revise the bid submission date.

(1) Responses to Questions:

QUESTION 0010: DIVISION 01 - GENERAL REQUIREMENTS 01 10 00 - GENERAL PARAGRAPHS, 1.02 BASIS FOR BIDS, 2) Dredging, B. Option Items: 1) Eelgrass Surveys and Reports. Please provide any existing eelgrass surveys of the dredge areas.

RESPONSE: The latest eelgrass survey, dated January 2018, is provided as an attachment to this amendment.

QUESTION 0011: INVITATION FOR BID NUMBER 70Z08819BPQQ10600, SECTION I, CONTRACT CLAUSES. FAR 52.211-12 Liquidated Damages - Construction was not included in the Contract Clauses. Please confirm that no liquidated damages will be assessed with this project.

RESPONSE: Liquidated damages will not be assessed for this contract.

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

15A. NAME AND TITLE OF SIGNER (Type or print) 16A NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

JASON DUGAN

15B. CONTRACTOR/OFFEROR 15C. DATE SIGNED 16B. UNITED STATES OF AMERICA 16C. DATE SIGNED

(Signature of person authorized to sign) (Signature of Contracting Officer)

NSN 7540-01-152-8070 30-105 STANDARD FORM 30 (REV. 10-83)PREVIOUS

EDITION UNUSABLE Prescribed by GSA, FAR (48 CFR) 53.243

Invitation For Bid Number 70Z08819BPQQ10600 Amendment 0004 May 10, 2019

QUESTION 0012: INVITATION FOR BID NUMBER 70Z08819BPQQ10600 SECTION B, SCHEDULE OF PRICES, CLIN 0005. There appears to be an error in the pricing schedule. CLIN 0005A and 0005AB reference Area B, rather than Area A.

RESPONSE: Correct; the error in the pricing schedule has been changed. CLIN005AA and CLIN005AB are in reference to the SF Small Boat Basin Area A. See attached revised Schedule of Prices.

QUESTION 0013: DIVISION 01 - GENERAL REQUIREMENTSÐ1 10 00 - GENERAL PARAGRAPHS, PART 1 GENERAL 1.01 SCOPE OF WORK: The specifications indicate the following: “The SF small boat basin shall be dredged to -10ft. MLLW plus 2ft. overdepth allowance in Area A, and -14ft. MLLW plus 2ft. overdepth allowance in Area B. Dredge material shall be transported and placed upland at the Montezuma Wetlands Restoration Site for beneficial reuse as cover and the at the Government furnished deep open ocean disposal Site (SF- DODS)."Please clarify how material is to be identified for disposal at SFDODS or Montezuma Wetlands?

RESPONSE: The material at the SF Small Boat Basin is suitable for unconfined aquatic disposal, meaning it can be disposed of at either SFDODS and/or Montezuma as cover. For pricing purposes, the USCG requests that all of the material from the SF Small Boat Basin be priced at the SFDODS cost regardless of final disposal location.

QUESTION 0014: 35 20 23 – Dredging. When was the last dredging event and please confirm all dredges areas have been previously dredged to the design depth indicated?

RESPONSE: The SF Small Boat Basin was last dredged in 2012 to depths ranging between -10ft to -16ft MLLW; this episode is considered maintenance dredging at this location. CGC ASPEN Mooring and Approach will be dredged for the first time; this episode is considered new dredging at this location.

QUESTION 0015:35 20 23 - Dredging 1.05 Obstruction of Work Area. Will USCG Vessels be moored in the small boat basin during dredging operations and what is the expected frequency and duration that the vessels will be leaving and entering the mooring area? Will the large USCG cutters be relocated during dredging? Will USCG Vessels be moored at the Aspen mooring during dredging operations and what is the expected frequency and duration that the vessels will be leaving and entering the mooring area?

RESPONSE: The USCG will make efforts to clear the moorings of smaller vessels and patrol boats in the SF Small Boat Basin, as well as the CGC ASPEN during the dredging event. However, it is likely that the Cutters located at the SF Small boat basin and the CGC ASPEN will be present during the dredging event. If they are present, the Contractor, in coordination with the vessel Captains, Facilities Engineer, and Contracting Officer, can determine ways to clear the work area so as to minimize effects to USCG operations, meanwhile clearing the moorings systematically so that the Contractor can access all areas necessary for dredging.

QUESTION 0016: Drawings. What is the distance between the eastern edge of the pier fingers and the western edge of the main pier? Or can the USCG provide an updated drawing showing actual locations of the piers?

RESPONSE: The shortest distance between the eastern edge of the pier fingers at the SF Small Boat Basin and the western edge of the main pier is approximately 100 feet. The hydrographic survey that was provided as part of the scope of work is the most up to date drawing.

QUESTION 0017: Drawings. Is the contractor expected to remove the free-standing piling at the south-west corner of the small boat pier?

RESPONSE: The Contractor shall remove the fallen steel- reinforced concrete pile (pile) located at the last floating dock in the SF Small Boat Basin.

QUESTION 0018: Sediment Sampling and Analysis Results. Can the USCG provide the appendices for the sediment sampling and analysis results reports provided in amendment 02?

RESPONSE: Because of the large size of the files, a copy of the appendices for the sediment sampling and analysis results reports can be provided to the Contractor upon award. The data in the appendices may be found at the following website: https://www.dmmosfbay.org

QUESTION 0019: 01 10 00 - General Paragraphs. Where is the temporary storage location for the jet docks?

RESPONSE: Temporary storage and protection of the jet docks is the responsibility of the Contractor.

QUESTION 0020: Schedule of Prices - Option CLIN 0008. The contractor will not be responsible for any dredge material below or near the floating jet docks if the option is not exercised, correct?

RESPONSE: The Contractor is responsible for all dredge material within the dredge footprint. The option item for the temporary removal and reinstallation will be exercised if the jet docks are in place during the dredging event. In the case that they are not, the Contractor shall still dredge the area.

QUESTION 0021: 01 00 00 - General Paragraphs. In order to avoid contingencies in bids, please specify whether there are liquidated damages that will apply to this job and, if so, please confirm the amount of such damages.

RESPONSE: See response to QUESTION 0011

QUESTION 0022: 01 00 00 - General Paragraphs. In order to reduce bid contingencies, please confirm that pursuant to 48 CFR § 49.505 that FAR 52.249-14 "Excusable Delays" applies to this contract in the event of a delay outside the reasonable control of the Contractor. If the answer is in the affirmative, please provide an amendment reflecting the inclusion of this clause.

May 10, 2019

RESPONSE: FAR 52.249-10(b) shall apply to this contract in the event any delays outside the reasonable control of the Contractor are encountered.

QUESTION 0023: 01 00 00 - General Paragraphs. Unlike land-based construction, completed dredging activities are subject to natural forces that are entirely outside the control of the Contractor. To clarify the intent of the warranty, please include the following warranty provision in an amendment: "Upon Contractor's advising the Contracting Officer that the dredging has been completed, the Contracting Officer shall inspect the Work and, if acceptable, shall advise Contractor of the Government's acceptance thereof. Contractor in no way represents, guarantees or warrants that any dredging or excavation will stay open, dredged or excavated for any period of time whatsoever.

RESPONSE: A post- dredge hydrographic survey submittal is required prior to final acceptance of the completed work. The post-dredge hydrographic survey shall be completed as soon as practicable, and no later than five (5) days after the completion of the entire work. The Contractor shall remove shoals and lumps by dragging the bottom or by dredging. However, if the bottom is soft and the shoal areas form no material obstruction to navigation, removal may be waived at the discretion of the Contracting Officer. When areas are found to be in satisfactory condition, the work therein will be accepted as complete. Final volume for payment will be subject to deductions for excessive overdepth, dredging outside of authorized areas, or disposal of material in an unauthorized manner. No shoals or lumps above project depth will be accepted or waived, as evidenced by multi-beam soundings. In the event sliding occurs in any excavation after its completion but prior to its acceptance, the Contractor shall remove such portions of the slide at no additional cost to the Government. Particular attention shall be provided to the slope nearest to the eastern edge of the float dock.

QUESTION 0024: 01 00 00 - General Paragraphs. Will the USCG extend the bid date one week to allow contractors sufficient time to review the responses to outstanding questions and any forthcoming amendments?

RESPONSE: See item 4 of this amendment.

(2) The response to Question 0008 issued in Amendment 003 is revised to read:

QUESTION 0008: IFB Section 3 Schedule of Prices. Cant the material in CLINs 0004AA & 0004AB in Area C, designated for SFDODS disposal, be transported upland?

RESPONSE: The material from Area C has to be disposed of at SFDODS. This is because it did not meet the thresholds for alternative disposal locations, such as the Montezuma Wetlands Restoration Project (Montezuma). The material from Areas A and B can be disposed of at either SFDODS or Montezuma. Overall, the material from the CGC ASPEN Mooring and Approach shall be split 50/50 between SFDODS and Montezuma (as cover), such that:

Area A+B: ~50,000 cy of cover quality sediment to reuse at Montezuma Wetlands Restoration Project

~39,000 cy to the San Francisco Deep Ocean Disposal Site (SFDODS) Area C: ~11,000 cy to SFDODS

(3) The Schedule of Prices is revised and hereby attached with this amendment.

(4) The submission date reflected in paragraph 13a. of the Standard Form 1442 is revised to read.

a. Sealed offers in original and 0 opies to perform the work required are due at the place specified in Item 8 by 2:00 P.M. (hour) local time on May 17, 2019.

May 10, 2019

SECTION B

SCHEDULE OF PRICES

MAINTENANCE DREDGING OF U.S. COAST GUARD CUTTER ASPEN MOORING AND APPROACH &

U.S. COAST GUARD STATION SAN FRANCISCO SMALL BOAT BASIN AT YERBA BUENA ISLAND, SAN

FRANCISCO CALIFORNIA (PSN 647873)

THE CONTRACTOR SHALL FURNISH ALL PLANT, LABOR, MATERIAL, EQUIPMENT, ETC., NECESSARY TO PERFORM ALL WORK IN STRICT ACCORDANCE WITH THE TERMS AND CONDITIONS SET FORTH IN THE

CONTRACT TO INCLUDE ALL ATTACHMENTS THERETO.

CLIN Description Unit of Issue

QTY Unit Price Total Amount

0001 Mobilization and Demobilization JOB 1 $ $

CLIN 0002: Dredging, CGC ASPEN Area A and Area B to -24-ft (MLLW) including 2-feet of Paid Overdepth with disposal at Montezuma Wetland beneficial use upland site.

Issue

EST

QTY

Unit Price Total Amount

0002AA Required Dredging to -24-ft MLLW In CGC ASPEN mooring Area A and Area B

CY 33,350 $ $

0002AB Overdepth Dredging to -26-ft MLLW in CGC ASPEN Area A and Area B

CY 16,650 $ $

CLIN 0003: Dredging, CGC ASPEN Area A and Area B to -24-ft (MLLW) including 2-feet of Paid Overdepth with disposal at SF-DODS.

Issue

EST

QTY

Unit Price Total Amount

0003AA Required Dredging to -24-ft MLLW In CGC ASPEN mooring Area A and Area B

CY 26,150 $ $

0003AB Overdepth Dredging to -26-ft MLLW in CGC ASPEN Area A And Area B

CY 12,850 $ $

CLIN 0004: Dredging, CGC ASPEN Area C to -24-ft (MLLW) including 2-feet of Paid Overdepth with disposal at SF-DODS

Issue

EST

QTY

Unit Price Total Amount

0004AA Required Dredging to -24-ft MLLW in CGC ASPEN mooring Area C

CY 8,200 $ $

0004AB Overdepth Dredging to -26-ft MLLW in CGC ASPEN mooring Area C

CY 2,800 $ $

May 10, 2019

CLIN 0005: Dredging, SF Small Boat Basin Area A to -10ft- (MLLW)plus -2ft-MLLW) of Paid Overdepth with disposal at SF-DODS and the transition zone from Area A to Area B to depths from -10ft-(MLLW) to -14-ft(MLLW)with disposal at SF-DODS

Issue

EST

QTY

Unit Price Total Amount

0005AA Required Dredging to -10-ft MLLW in Small Boat Basin Area A

CY 3,000 $ $

0005AB Overdepth Dredging to -12-ft MLLW in SF Small Boat Basin Area A

CY 1,200 $ $

0005AC Required Dredging of transition zone from Area A to Area B to depths from -10ft- (MLLW)to -14-ft MLLW in SF Small Boat Basin

CY 300 $ $

CLIN 0006: Dredging, SF Small Boat Basin Area B to -14-ft (MLLW) including 2-feet of Paid Overdepth with disposal at SF-DODS

Issue

EST

QTY

Unit Price Total Amount

0006AA Required Dredging to -14-ft MLLW in Small Boat Basin Area B

CY 9,000 $ $

0006AB Overdepth Dredging to -16-ft MLLW in SF Small Boat Basin Area B

CY 4,700 $ $

OPTION

CLIN

Description Unit of Issue

QTY Unit Price Total Amount

0007 Eelgrass Survey JOB 1 $ $

GRAND TOTAL ITEMS 0001- 0007 $

Notes:

*QUANTITIES FOR CLINS 0002AA, 0002AB, 0003AA, 0003AB, 0004AA, 0004AB, 0005AA, 0005AB, 0005AC, 0006AA, and

0006B ARE STIMATED AMOUNTS; SEE FAR 52.211-18 IN SECTION F

1. Prices must be submitted on all individual items within the Schedule of Prices. Failure to do so may be cause for rejection of bids.

2. CLIN 0007 Option Line Item. The exercise and award of CLIN 0007 will be made within 60 days after contract award. Award of CLIN 0007 will be dependent on the availability of funds.

3. The term "JOB", which appears on the Schedule of Prices under “Unit of Issue” for Bid Item No. 0001 and 0007 shall be considered as a Lump Sum. The Variation in Estimated Quantities contract clause, FAR 52.211-18, shall not apply to CLINs 0001 and Option

CLIN 0007.

Arcadis U.S., Inc.

2300 Clayton Road

Suite 400

Concord

California 94520

Tel 925 274 1100

Fax 925 726 0121 www.arcadis.com

Page:

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Ms. Gilda Barboza Project Manager United States Coast Guard Civil Engineering Unit Oakland 1301 Clay Street, Suite 700N Oakland, CA 94612-5203

Subject:

Eelgrass Survey for New and Maintenance Dredge Footprints, Sector San Francisco, Yerba Buena Island, City and County of San Francisco, California

Dear Ms. Barboza:

At the request of the United States Coast Guard (USCG) Civil Engineering Unit (CEU) Oakland, Arcadis U.S., Inc. (Arcadis), managed and supervised an eelgrass (Zostera marina) survey of the new and maintenance dredging footprints at the USCG Sector San Francisco (SSF) facility at Yerba Buena Island, City and County of San Francisco, California (Figure 1). The work described was performed in accordance with the USCG CEU Oakland Scope of Work dated September 2017 for Contract No. HSCG50-14-D-PSL007, Task Order HSCG88-17-J-PQQ179, and applicable regulatory guidance.

Background

Eelgrass is considered an essential fish habitat for a number of threatened or endangered fish species by the National Marine Fisheries Service (NMFS). The first official regulatory policy regarding eelgrass protection on the west coast was established by the National Oceanic and Atmospheric Administration (NOAA) Southern California Eelgrass Mitigation Policy (adopted 31 July 1991). This has since been replaced by the California Eelgrass Mitigation Policy and Implementing Guidelines (CEMP; NOAA 2014). In June of 2011, the U.S. Army Corps of Engineers (USACE) and the U.S. Environmental Protection Agency (USEPA) issued the Agreement on Programmatic EFH Conservation Measures for Maintenance Dredging Conducted Under the LTMS Program, based on consultation documentation prepared by NMFS and issued on July 13, 2010. As part of this agreement, the USACE and USEPA have agreed to implement avoidance and mitigation measures as appropriate for a given project based on specific site conditions. These measures include pre- and post-dredge eelgrass surveys, mitigation for indirect impacts through eelgrass marking, implementation

ENVIRONMENT

Date:

January 3, 2018

Contact:

Josh Gravenmier

Phone:

925-296-7858

Email:

Josh.Gravenmier@ arcadis.com

Our ref:

B0003010.0004 arcadis.com USCG Sector SF Eelgrass Survey

Ms. Gilda Barboza 03 January 2018

Page:

2/5 of turbidity controls or light monitoring, and mitigation for direct impacts to eelgrass through mitigation as guided by the CEMP (NOAA 2014).

Identification of the eelgrass beds in the vicinity of the SSF site will assist USCG in determining what (if any) avoidance and mitigation measures in the vicinity of the new and maintenance dredge footprints are necessary to satisfy the NMFS mandate to minimize to the extent practicable adverse effects on such habitat and encourage the conservation and enhancement of that habitat (as per the Magnuson-Stevens Fishery Conservation and Management Act, as amended by the Sustainable Fisheries Act of 1996).

Eelgrass in the San Francisco Bay is restricted to a narrow intertidal range between approximately +1 feet Mean Lower Low Water (MLLW) and -7 feet MLLW. Its depth range at a site is dependent upon water turbidity as plant growth is light limited (Zimmerman et al. 1991). The Study Area for the survey was therefore limited to those areas where eelgrass growth was possible (inclusive of a buffer). The Study Area was approximately 24 acres (Figure 2), which includes the maintenance dredge area, a 150-foot buffer, and an approximately 200-foot wide by 1,600-foot long area along the USCG wharf to accommodate the potential near-shore areas associated with the new dredging area and a buffer area to the south. The survey took place during the active growing season for eelgrass in San Francisco Bay as defined by the CEMP (April through October). Based on growth within the Study Area, eelgrass density was minimal at the time of the survey, but adequate for determining the outer margins of the eelgrass beds. In addition, the area surrounding the docks were walked to visually assess the area for eelgrass during the low tide.

Survey Methods

On 16 October 2017, side scan survey data was collected to determine the potential presence or absence of eelgrass in the intertidal zones within the dredging footprint areas capable of supporting eelgrass growth, as well as a buffer outside both the new and maintenance dredge footprints using a 24-foot survey vessel Beaver operated by PCH Survey, Inc. Prior to the survey, the 2014 baywide eelgrass survey (Merkel 2014) was reviewed for eelgrass mapped in the vicinity of the Study Area. Weather conditions were favorable for the collection of accurate data (sunny, clear, and a slight breeze) and seas were calm in areas adjacent to the shoreline and mild with waves up to 2 feet further away from the shoreline. Survey conditions coincided with a rising tide from 5.7 feet above MLLW at 09:32 AM and 6.0 feet above MLLW at 10:31 AM (Yerba Buena Island station 9414782). Sub-meter accuracy for horizontal positioning was achieved using a Trimble 860 differential global positioning system (DGPS) onboard the survey vessel. The horizontal datum for the data collected was in feet using the NAD 83, California State Plane System, Zone 3. The vertical datum was in MLLW in feet.

Multiple side scan survey transect lines were run in the Study Area. Transects were spaced at 70-foot intervals. Sidescan sonar images (TIFF format) were received from PCH hydrographers and analyzed using eCognition 4.0 software (Definiens Imaging 2005) in combination with ArcGIS. eCognition is a remote-sensing application that is used to interpret features usually from satellite images and aerial photographs. The sidescan sonar images were processed and digitized to report eelgrass density. After the image was processed, segments of eelgrass of various densities were selected and used as baseline samples to determine eelgrass density signatures. The eelgrass densities were categorized into the following density ranges: 0-5%, 6-20%, 21-40%, and above 41-100%. The software was then used to identify other segments of similar intensity throughout the Study Area and assign them to the proper

3/5 occurrence and density category. These segments were then exported to GIS format (shapefile) and processed using for mapping purposes. Acreages for each density category were then calculated.

The eelgrass survey was performed using sidescan sonar to comply with requirements of the NOAA West Coast Fisheries (NOAA 2014) for eelgrass surveys completed in areas that cannot be safely surveyed on foot at low tide in San Francisco Bay.

Verification Locations Areas where sidescan imagery indicated presence of eelgrass were field-verified using underwater imagery and live video to determine the presence of local plant material. During the sidescan survey, the operator visually noted areas of potential eelgrass occurrence (image roughness at depths shallower than 10 feet MLLW) and recorded those locations. A remotely-operated underwater vehicle outfitted with a navigation system and high definition video camera was deployed to obtain video in each of those four target locations. Video was obtained, and any occurrence of eelgrass was noted in the video files. The combined sidescan survey and still images of the videos at verification locations are included in Appendix A.

Four verification locations were identified in the southern extent of the identified eelgrass bed (Exhibit 1 is a closeup of Figure A1 in Appendix A). Three of the locations had confirmed eelgrass. The fourth location was determined to be macroalgae on rocks.

Exhibit 1. Verification Locations

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Results

One area of eelgrass, comprising approximately 1.40 acres, was mapped within the Study Area during the 2017 eelgrass survey (Figure 3). No eelgrass was observed within either dredge footprint. The location of the observed eelgrass bed with both the new and maintenance dredge limits and the depth contours from a concurrent bathymetric survey are shown in Figure 4.

The eelgrass survey for USCG SSF indicates that:

• No eelgrass was observed within the maintenance dredge limit;

• No eelgrass was observed within the new dredge limit;

• One eelgrass bed was mapped approximately 55 meters north of the maintenance dredge limit;

and

• The mapped eelgrass bed is located approximately 200 meters from the new dredge limit.

A previous eelgrass survey was conducted at the site in February 2010 at the request of the Dredged Material Management Office (DMMO). This survey identified an eelgrass bed northwest of the maintenance dredge area in approximately the same area as the 2017 eelgrass survey (Arcadis 2010).

The eelgrass observed in 2010 is in the same general location as the most recent survey, which would result in a similar proposed silt curtain location during dredging as highlighted in the San Francisco Bay Regional Water Quality Control Board (RWQCB) water quality certification (CIWQS Place No. 782244) to avoid adverse effects to eelgrass from dredging-related turbidity (Appendix B).

Conclusions

Based on the observations stated above, Arcadis concludes the new and maintenance dredging activity will be located greater than 45 meters from observed eelgrass beds (a distance which is protective of the eelgrass beds and accounts for population fluctuations over time) and will not directly impact eelgrass.

Eelgrass will be within 250 meters of the dredge footprints and thus will be considered to still have indirect impacts to eelgrass which may result in the implementation of additional dredging best management practices (i.e., silt curtains).

If you have any questions or require any additional information, please contact Josh Gravenmier.

Sincerely, Arcadis U.S., Inc.

Josh Gravenmier Vice President/Project Manager

Brianne Zorn Environmental Scientist

5/5

Copies:

Janice Preston, USCG

References

Arcadis. 2010. Eelgrass Survey for Sector San Francisco Dredge Footprint, Yerba Buena Island, San Francisco, California. Prepared for the US Coast Guard, Order Number HSCG88-10-J-PQQ190.

August.

Assessment of Environmental suitability for growth of Zostera marina (eelgrass) in San Francisco Bay.

Aquatic Botany 39: 353-366.

NOAA Fisheries, West Coast Region. 2014. California Eelgrass Mitigation Policy and Implementing Guidelines. October.

Merkel and Associates. 2014, as cited in California Department of Fish and Wildlife 2016. Baywide Eelgrass Inventory of San Francisco Bay. Available online at https://map.dfg.ca.gov/metadata/ds1503.html. Accessed 09/19/2017.

Zimmerman, R.C., J.L. Reguzzoni, S. Wyllie-Echeverria, M. Josselyn, and R.S. Alberte. 1991.

Enclosures

Figures

1 Site Vicinity Map

2 Eelgrass Study Area 16 October 2017

3 Eelgrass Observed in Study Area

4 Dredge Limits and Eelgrass

Appendix

A 16 October 2017 Sidescan Eelgrass Survey Verification Photographs (WRA 2017)

B Proposed Silt Curtain Location Based on the 2010 Eelgrass Survey https://map.dfg.ca.gov/metadata/ds1503.html.%20Accessed%2009/19/2017

FIGURES

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NOTE:

ROAD MAP COURTESY OF ESRI.

UNITED STATES COAST GUARD

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SITE VICINITY MAP

FIGURE

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NOTES:

1. 2016 IMAGERY OBTAINED FROM ESRI IMAGE SERVICE.

2. EELGRASS SURVEY CONDUCTED BY PCH SURVEY, Inc, on October 16, 2017.

LEGEND:

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SECTOR SAN FRANCISCO, CITY AND COUNTY OF SAN FRANCISCO, CA

EELGRASS STUDY AREA

16 OCTOBER 2017

FIGURE

EELGRASS SURVEY REPORT

Sector San Francisco

U.S. Coast Guard Cutter Aspen Mooring Location

NOTES:

1. 2016 IMAGERY OBTAINED FROM ESRI IMAGE SERVICE.

2. EELGRASS SURVEY CONDUCTED BY PCH SURVEY, Inc, on October 16, 2017.

UNITED STATES COAST GUARD

SECTOR SAN FRANCISCO, CITY AND COUNTY OF SAN FRANCISCO, CA

EELGRASS OBSERVED IN STUDY AREA

FIGURE

EELGRASS SURVEY REPORT

LEGEND:

STUDY AREA

NEW DREDGE AREA

MAINTENANCE DREDGE AREA

Eelgrass Coverage 1-5% (0.43 ac.)

6-21% (0.37 ac.)

21-40% (0.29 ac.)

41-100% (0.31 ac.)

0 360 720 Feet

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APPROXIMATE STORMWATER OUTFALL

LOCATION

DEPTH CONTOUR LINE

1. BASE MAP WAS TAKEN FROM A DRAWING ENTITLED "CIVIL

CONDITION HYDROGRAPHIC SURVEY" AT A SCALE OF

1"=50' DATED 3/31/99 AND WAS PROVIDED BY USCG.

2. BATHYMETRIC AND EELGRASS DATA IS FROM A SURVEY

CONDUCTED BY PCH SURVEY ON 16 OCTOBER 2017 AND

REPRESENTS THE SEAFLOOR CONDITIONS PRESENT ON

THAT DATE.

3. DEPTHS DEPICTED IN FEET ABOVE OR BELOW MEAN

LOWER LOW WATER (MLLW).

NOTES

FIGURE

UNITED STATES COAST GUARD

SECTOR SAN FRANCISCO, CITY AND COUNTY OF SAN FRANCISCO, CA

EELGRASS SURVEY REPORT

FEET

125' 0

125' 250'

METERS

0 4020 601030 1020

APPENDIX A

16 October 2017 Sidescan Eelgrass Survey Verification Photographs

(WRA 2017)

Yerba Buena Island Sidescan Eelgrass Survey US Coast Guard Sector San Francisco and Station San Francisco Marin County, CA

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Sources: Esri Streaming - NAIP 2016, WRA | Prepared By: smortensen, 12/1/2017

Verification Points

Eelgrass Extent

Study Area

Maintenance Dredge Area

New Dredge Area

Eelgrass Coverage 1-5% (0.43 ac.)

6-21% (0.37 ac.)

21-40% (0.29 ac.)

41-100% (0.31 ac.)

0 400200 Feet

Figure A1. Sidescan Sonar Imagery

1 2

Inset

Target Easting Northing Identification 1 6024136.1 2123511.9 eelgrass 2 6024223.8 2123512.2 eelgrass 3 6024248.8 2123578.4 eelgrass 4 6024098.9 2123361.6 nearshore

Photograph 1. Verification Site 1; Eelgrass present within sandy substrate. Still frame captured from remotely operated vehicle video by Pacific Coast Habitat Survey, October 6, 2017.

Photograph 2. Verification Site 2; Eelgrass present within sandy substrate. Still frame captured from remotely operated vehicle video by Pacific Coast Habitat Survey, October 6, 2017

Appendix A. Eelgrass Verification Photographs A-2

Photograph 3. Verification Site 3; Eelgrass present within sandy substrate. Still frame captured from remotely operated vehicle video by Pacific Coast Habitat Survey, October 6, 2017.

Photograph 4. Verification Site 4; Eelgrass absent. Large rocks with attached macroalgae present within surrounding sandy substrate. Still frame captured from remotely operated vehicle video by Pacific Coast Habitat Survey, October 6, 2017.

Appendix A. Eelgrass Verification Photographs A-3

APPENDIX B

Proposed Silt Curtain Location Based on the 2010 Eelgrass Survey