24B0010 Amendment 1 Updated 7.5.2024.pdf

AMENDMENT OF SOLICITATION/MODIFICATION OF 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)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83)

Prescribed by GSA

FAR (48 CFR) 53.243

Summary of Changes:

1. CONTRACT ID CODE PAGE OF PAGES

1 316

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

16C. DATE SIGNED

BY

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

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

8. NAME AND ADDRESS OF CONTRACTOR (No., Street, County, State and Zip Code) X W912P724B0010

X 9B. DATED (SEE ITEM 11)

11-Jun-2024

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer X is extended, is not extended.

Offer 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 ACKNOWLEDGMENT 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 date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE 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 copies to the issuing office.

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

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/MODIFICATION NO.

5. PROJECT NO.(If applicable)

6. ISSUED BY

3.EFFECTIVE DATE

05-Jul-2024

CODE

USACE, SAN FRANCISCO DISTRICT

450 GOLDEN GATE

SAN FRANCISCO CA 94102

W912P7 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

1. Extended bid due date and bid opening date to July 12th, 2024.

2. Change to specifications 01 11 00, Summary of work under Para 1.1.1 (b). Please see tracked changes on following pages.

3. Including Biological Opinion and related permits as attachments.

a. NMFS BiOp

b. USFWS BiOp

c. Water Quality: WDR for Clamshell (Mechanical Dredging)

d. Water Quality (MOU (General Delta)

4. RFI's and correlating responses posted to SAM.gov solicitation posting.

W912P724B0010 Amendment 1

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION 00 10 00 - SOLICITATION

The required response date/time has changed from 11-Jul-2024 12:00 PM to 12-Jul-2024 12:00 PM.

(End of Section 00 10 00 Changes)

1. Extended bid due date and bid opening date to July 12th, 2024.

2. Change to specifications 01 11 00, Summary of work under Para 1.1.1 (b). Please see tracked changes on following pages.

3. Including Biological Opinions and related permits as attachments.

a. NMFS BiOp

b. USFWS BiOp

c. Water Quality: WDR for Clamshell (Mechanical Dredging)

d. Water Quality (MOU (General Delta)

4. RFI's and correlating responses posted to SAM.gov solicitation posting.

(End of Summary of Changes)

W912P724B0010

To submit a bid, each bidder must contact Logan Champlin to obtain a unique DoD SAFE submittal code. Logan Champlin can be reached at logan.champlin@usace.army.mil or (415)503-6953. In the event Logan Champlin cannot breached, please contact Melissa DeNigris at (916) 557-5137, to request assistance.

Once a bidder has a unique submittal code, they may upload their bid submission to DoD SAFE. All submissions may be up to 6 calendar days prior to Bid Opening. Early and late submissions outside of this window will not be accepted. The public bid opening will be held via WebEx at 01:00 pm PST on July 11th 12th, 2024, which will allow participants to hear a live reading of the bids. Prior to the bid opening, participants must follow this link: https://usace1.webex.com/meet/melissa.a.denigris. Government will review the bids received electronically and post the abstracts of bids on sam.gov as soon as practicable after bid closing.

It is the responsibility of all bidders to ensure their bid submissions are complete, inclusive of the price schedule, acknowledge of amendments, bid guarantee, and all additional information requested through this advertisement.

1.8 OTHER BIDDELIVERY METHODS

Telegraphic, Facsimile, emailed, HAND DELIVERED, MAILED, or comparable delivery methods of the

Bid Package are not acceptable.

Bids may only be modified or withdrawn by electronic means through a signed letter request uploaded to DoD SAFE using the same request code as the original bid. A notice to modify or withdraw a bid sent via DoD SAFE must be received in DoD SAFE no later than the exact date and time set for Bid Opening.

1.9 PERFORMANCE AND PAYMENT BONDS

The offerer will, furnish performance and payment bonds within the time established in the contracting in accordancewith FAR 52.228-15 (DEVIATION 2020-O0016) located in Section 00 72 00.The offeror will provide the bonds to the Government electronically via the DoD SAFE. The offeror will a lso mail original,hard copies of bid bonds and performance bonds to the U.S. Army Corps of Engineers, San Francisco District, Contracting Division, 450 Golden Gate Avenue, Fourth Floor, San Francisco, CA 94102.

2.0 INDIVIDUAL SURETIESIN SUPPORT OF BID BONDS

An offerer utilizingindividual sureties in support of a bid bond shall include a Standard Form (SF) 28 (Affidavit of Individual Surety), accompanied by a pledge of acceptable assets from each person actingas an individual surety, and include these with the SF 24 (Bid Bond), and the proposal itself (see clause titled "Pledges of Assets," FAR 52.228-11 DEVIATION 2020-O0016).

Pledges of acceptable assets shall be in the form of (1) evidence of an escrow account and/or (2) a recorded lien on real estate.

Failure to provide required documentation described herein may cause the offerer to be deemed "unacceptable".

2.1 BID GUARANTEE FORM AND AMOUNT

The offerer shall furnish a separate bid guarantee in accordancewith the solicitation provision titled "Bid Guarantee", FAR 52.228-1. In accordance with FAR 28.101-2 (b) the bid guarantee amount shall be at least 20 percent of the“proposed price" but shall not exceed$3 million. When the penal sum is expressed as a percentage, a maximum dollar limitation maybe stated.

In accordance with FAR 28.106-1 a Standard Form (SF) 24 shall be used for the bid bond.

In accordance with FAR 28.202(a) (1), corporate sureties utilized must appear on the list contained in the

Section 00 21 00- Page 3

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W912P724B0010

San Joaquin - Stockton DWSC FY24 Dredging W912P724B0010

SECTION 01 11 00

SUMMARY OF WORK

08/11

PART 1 GENERAL

1.1 PROJECT DESCRIPTION

The work includes annual maintenance dredging of the federal navigation channel in the San Joaquin River / Port of Stockton Deep Water Ship Channels (DWSC),which cannot begin before 1 August in any year and must be completed by 30 November. The period of performance will not be extended to the following calendar year.

1.1.1 Requirements

a. Dredge the specified dredge reaches to -35-ft MLLW plus 1-ft of allowable paid overdepth in San Joaquin River / Stockton DWSC in all Reaches, except for the Sediment Trap, which shall be dredged to -38.5-ft MLLW with 1-ft of allowable paidoverdepth. All dredge material is suitable for Government furnished upland sites at Antioch Dunes,Scour Pond, Bradford Island, Mandeville, Tule Island, Roberts Island II, Roberts Island I, Rough and Ready Island . Dredge material may be suitable for beneficial reuses at Contractor furnished sites in accordance with the permit requirements of the specific reuse sites.

The most recent sediment sampling report is attached at the end of the specification package.

b. Dredging operations in the San Joaquin River / Stockton DWSC shall begin at the downstream end of the channel (dredge reach 1) and continue in ascending order towards the upstream of the channel.

c. If a second dredge plant is used, dredging operations shall follow the order of the aforementioned requirement (item b). Multiple dredge plants shall not work in the same dredge reach.

d. The Contractor is responsible for hiring a 3rd party Contractor to fulfill the requirements of fish monitoring and water quality monitoring tasks. Upon request by the Government, the Contractor shall also coordinate with Government personnel to allow oversight of the monitoring efforts.

e. Fish entrainment monitoring shall be performed on at least 30% of the dredged material.

f. If Government furnished upland dredged material placement sites are used, the Contractor shall notify the Government 72 hours prior to starting site work at Government-furnished placement sites.

g. This project can be dredged either with a clamshell dredger or a hydraulic cutterhead dredger. If a hydraulic cutterhead dredger is used, the hydraulic cutterhead plant(s) shall have a minimum of 16-in diameter pipeline and 1,800 horsepower for the main pump engine.

h. The Contractor is responsible for dredge material placement site preparation and dredge material management. See Section TEMPORARY ENVIRONMENTAL CONTROLS 01 57 19 for additional requirements.

SECTION 01 11 00 Page 1 June 09, 2024

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W912P724B0010

United States Department of the Interior

FISH AND WILDLIFE SERVICE

San Francisco Bay-Delta Fish & Wildlife Office

650 Capitol Mall, Suite 8-300

Sacramento, California 95814-4700

In reply refer to:

2023-0018864-S7-001

June 27, 2023

Mr. Marshall K. Harper

Chief, Environmental Resources Branch

United States Department of the Army

Army Corps of Engineers, Sacramento District

1325 J Street

Sacramento, California 95814-2922

Subject: Reinitiation of Consultation for the Stockton Deep Water Shipping Channel

Dredging and Bank Stabilization Project, Sacramento, Contra Costa, and San

Joaquin Counties, California (Service File No. 08FBDT00-2017-F-0099)

Dear Mr. Harper:

This letter is in response to the U.S. Army Corps of Engineers’ (Corps) January 30, 2023, letter requesting reinitiation of formal consultation with the U.S. Fish and Wildlife Service’s (Service) on the Stockton Deep Water Shipping Channel Dredging and Bank Stabilization Project

(project), Sacramento, Solano, and Yolo Counties, California (Service File No. 08FBDT00-

2017-F-0098) (September 1, 2017 BO). Your request was received via electronic mail (email) on

January 30, 2023.

The Corps is proposing to extend the consultation for 5 years covering dredge seasons 2023-

2028 to incorporate mechanical clamshell dredging in addition to maintenance dredging conducted with a cutterhead hydraulic suction dredge on the Stockton Deep Water Shipping

Channel (SDWSC). The Corps has determined the proposed project will likely adversely affect the federally threatened giant garter snake (Thamnophis gigas) (GGS), the federally threatened delta smelt (Hypomesus transpacificus) and its designated critical habitat. The Corps has also determined that the project may affect, but is not likely to adversely affect the federally endangered Lange’s metalmark butterfly (Apodemia mormo langei; LMB), the federally endangered Antioch dunes evening primrose (Oenothera deltoides ssp. howellii; AEP), and the federally endangered Contra Costa wallflower (Erysimum capitatum var. angustatum; CCW). In addition, the Corps is requesting a conference opinion on the San Francisco Bay-Delta distinct population segment (DPS) of the longfin smelt (Spirinchus thaleichthys), which is proposed for listing as endangered under the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et

W912P724B0010 Amendment 1

W912P724B0010

Mr. Marshall K. Harper 2 seq.) (Act). This response is provided under the authority of the Act, and in accordance with the implementing regulations pertaining to interagency cooperation (50 CFR 402).

In reviewing this project, the Service has relied upon: (1) the Corps’ January 30, 2023, letter requesting reinitiation of the September 1, 2017 BO; (2) the January 2023 Programmatic

Biological Assessment for the Stockton Deep Water Ship Channel Maintenance Dredging and

Bank Protection Project, Contra Costa, Sacramento, and San Joaquin Counties, California (BA) prepared by the Corps; (3) the September 1, 2017, biological opinion (Service File No.

08FBDT00-2017-F-0098); (4) the March 19, 2019, amendment to the September 1, 2017 BO

(Service File No. 08FBDT00-2017-F-0098-1); (5) the March 14, 2022 one-year extension of the consultation for the project; (6) several emails, telephone conversations between the Service, the

Corps, and their consultant; and (7) other information available to the Service.

The Service concurs with the Corps that the proposed project is not likely to adversely affect the

LMB, the AEP, or the CCW. As part of the Comprehensive Conservation Plan (CCP) for the

Antioch Dunes National Wildlife Refuge (ADNWR), dune restoration is one of the primary objectives for habitat restoration (Service 2019). Beginning in 1991, the Service has imported sand to the ADNWR in order to create additional habitat. The CCP specifies identifying potential sources of clean sand, specifically from the SDWSC, and importing the sand for habitat restoration. In 2013, the Service and the Port of Stockton came to an agreement that the sandy material dredged by the Corps could be used to restore the sand dune habitat required by the species. This area is anticipated to be used as a dredge material placement site in order to reduce the invasive non-native species in the area and restore the naturally occurring sand dunes. Prior to each proposed dredging season, The Corps would coordinate with the Service, the National

Marine Fisheries Service (NMFS), and the California Department of Fish and Wildlife (CDFW) to avoid any adverse effects to listed species or habitats. Due to the sensitive species in this area, the area would be cleared of seeds and/or propagules by Service staff prior to dredge material placement. All material placement in the ADNWR would be coordinated with the Service. In addition, a biological monitor would conduct pre-dredging surveys prior to all maintenance dredging in order to avoid adverse effects to the Antioch dune species.

The remainder of this document represents the Service's biological opinion on the effects of the

2023-2028 5-year implementation of the SDWSC project on the GGS, the delta smelt, and the delta smelt's critical habitat and the Service’s conference opinion on the longfin smelt.

Consultation History

September 1, 2017 The Service issued the BO for the project.

March 13, 2019 The Service received the Corps’ March 8, 2019 request for reinitiation to extend the in-water work window.

October 30, 2019 The Corps, Service, and National Marine Fisheries Service

(NMFS) met to discuss the extensions to the listed species in-water work windows.

W912P724B0010

Mr. Marshall K. Harper 3

October 31, 2019 The Corps withdrew the March 8, 2019 reinitiation request.

June through July 2018 The Service provided technical assistance regarding adding the

Tule Island Dredging Material Placement Site (DMPS)

November 18, 2018 The Corps reinitiated formal consultation with the Service for the addition of the Tule Island DMPS.

March 21, 2019 The Service issued the amended biological opinion (Service File.

No. 08FBDT00-2017-F-0098-1) that includes the Tule Island

DMPS.

January 19, 2022 The Corps requested a one-year extension for the project’s consultation to dredge in 2022 with the intent to reinitiate for the next 5-year dredging program in the fourth quarter of fiscal year

2022.

March 14, 2022 The Service issued a one-year extension for the project’s consultation to dredge in the calendar year 2022 work window of

August 1 through October 31.

January 30, 2023 The Service received the request to reinitiate the July 17, 2017 BO for dredging in years 2023 through 2028.

February 2, 2023 The Corps and the Service held a telephone conversation about species effects determinations and an effects determination for the delta smelt’s critical habitat for the project. The Corps was changing their determinations for the San Joaquin kit fox (Vulpes macrotis mutica), the valley elderberry longhorn beetle

(Desmocerus californicus dimorphus), and the California least tern

(Sterna antillarum browni), and that they were changing their determination for the delta smelt’s designated critical habitat from may affect, but not likely to adversely affect to may affect and is likely to adversely affect, but would not adversely modify the critical habitat.

June 6, 2023 The Corps sent the Service an email confirming the February 3, 2023, telephone discussion that the Corps had changed the determinations to “no effect” for the San Joaquin kit fox, the valley elderberry longhorn beetle, and the California least tern. The Corps also confirmed from the February 3, 2023, discussion that they had changed their determination for the delta smelt’s designated critical habitat from may affect, but not likely to adversely affect to may affect and is likely to adversely affect, but would not adversely modify the critical habitat.

W912P724B0010

Mr. Marshall K. Harper 4

BIOLOGICAL AND CONFERENCE OPINION

Description of the Proposed Action

The Corps proposes to continue routine maintenance dredging and bank protection on the

SDWSC. The proposed action includes dredge work using hydraulic or mechanical dredging methods. The exact methods could include hydraulic cutterhead pipeline, mechanical bucket, or mechanical backhoe dredging and would depend on the contractor and site conditions. The rock placement would be accomplished with a clamshell crane with rock transported via barges, or by truck, depending on site conditions. The dredged material would be deposited at previously authorized DMPS (Table 1) and several new proposed DMPSs. Dredge slurry would be routed to the DMPS via pipelines or barges. The DMPS would be diked to allow dredge slurry to settle and consolidate. Decant water would then be discharged back into the SDWSC, as determined during annual coordination with the Corps, dredge contractor, and the Central Valley Regional

Water Quality Control Board (CVRWQCB). Dredged spoils would be allowed to dry in the

DMPS. The bank protection rock placement may be placed at any site that previously contained bank protection work, and where there is a need for additional rock due to bank erosion. The proposed action would follow specific work windows to minimize impacts to species.

Table 1. SDWSC DMPS, listed in order going upstream, including proposed sites.

Placement

Site

Area

(acres)

Method of Return

Water

Point of

Contact

Special

Requirements

Landing Point;

Line Pump

Allowance

Montezuma

Wetlands

(proposed)

(Phase II)

Gravity. Water leaves site through return water channel, which conveys it to the make-up pond.

Montezuma

Wetlands, LCC

Habitat restoration site; Off-loading by barge/scow only

Station number

2+00;

Antioch

Dunes

8 Gravity. Water leaves site through gravity drain into the San

Joaquin River.

Port of

Stockton

Habitat restoration site so minimize impacts.

Station 314+00;

Allowance 2,300 feet

Sherman

Island Scour

Pond

125 Pump. Water leaves site by gravity into agriculture canal with pump out provided by

Reclamation District

(RD) 341.

Port of

Stockton /

RD 341

Site underlain by peat; no placement or decant water in adjacent pond.

Station 423+00;

Allowance 900 feet

Sherman

Island

McCormack

Pit

26 Pump. Water leaves site by gravity into agriculture canal with pump out provided by

RD 341.

Port of

Stockton /

RD 341

Site underlain by peat.

Station 564+00;

Allowance 3,700 feet

Bradford

Island I

110 Pump. Water leaves site by gravity into agriculture canal, which

Contractor must then pump out.

Port of

Stockton

Only access to island is by boat;

agriculture ditch pumped out by RD

2059 / Port owned pumps.

Station 740+00;

Allowance 500 feet

Bradford

Island II

(proposed)

18 Pump. Water leaves site by gravity into agriculture canal, which

Port of

Stockton

Only access to island is by boat;

agriculture ditch

Station 940+00;

Allowance 650 feet

W912P724B0010

Mr. Marshall K. Harper 5

Contractor must then pump out.

pumped out by RD

2059 / Port owned pumps.

Twitchell

Island South

18 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 950+00;

Twitchell

Island

North

35 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Berm construction and dredged material placement should avoid irrigation/drainage canal; dredge pipeline may be positioned across the canal.

Station 1050+00;

Venice Island

I (proposed)

24 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1210+00;

Allowance 5,300 feet

Venice Island

II (proposed)

13 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1260+00;

Allowance 480 feet

Venice Island

III (proposed)

11 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1280+00;

Allowance 750 feet

Mandeville

Island

34 Water leaves site by gravity into agriculture canal.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1300+00

Venice Island

IV (proposed)

31 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1350+00;

Allowance 4,800 feet

Venice Island

V (proposed)

13 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1360+00;

Allowance 5,450 feet

W912P724B0010

Mr. Marshall K. Harper 6

Venice Island

VI (proposed)

16 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1430+00;

Allowance 750 feet

McDonald

Island

(proposed)

18 Pump. Water leaves site by gravity into agriculture canal, then to San Joaquin River via pump.

Port of

Stockton

Irrigation/drainage canal likely regulated by the

Corps, CVRWQCB, and

CDFW.

Station 1515+00;

Allowance 4,100 feet

Tule Island 9 Gravity. Water leaves site by exiting weir box.

Port of

Stockton

Adjacent property

CDFW owned and operated conservation easements.

Station 1586+00;

Allowance 300 feet

Roberts

Island II

220 Pump. Port of

Stockton

May be under cultivation.

Station 1618+00 to 1840+00;

Allowance 300 feet

Roberts

Island I

250 Pump. Port of

Stockton

May be under cultivation.

Station 1895+00 to 1975+00;

Allowance 300 feet

Rough and

Ready Island

West

Complex

50 Pump. Port of

Stockton

N/A Station 2105+00;

Allowance 2,750 feet

Dredging methods

Prior to each proposed dredging season, the Corps will coordinate with the Service, NMFS, and

CDFW. This coordination will include documentation of exact reaches of the SDWSC to be dredged, schedule for that dredging year, and which DMPS would likely be used. If there are changes to DMPS boundaries, location, or function, separate documentation will be provided to the agencies for approval. A maintenance dredging work window is proposed to follow a yearly schedule from July 1 through November 30 for the Stockton DWSC. From July 1 through July

31, dredging on the SDWSC would only be permitted between the Roberts II DMPS and the Port of Stockton. A standard 2-week extension is also proposed, after concurrence with the Service, extending dredging in the SDWSC to December 15, on a case-by-case basis. All sites would be dredged to maintain the current depth: the lower portion of the channel would be maintained at a depth of 30 feet below mean lower low water (MLLW), and the upper portion of the channel would be maintained at a depth of 35 feet below MLLW. An allowable over depth of 1 or 2 feet is also anticipated for all sites. These depths maintain safe conditions for ships using the channels while not increasing the quantity or size of commercial navigation traffic.

The proposed project will use hydraulic or mechanical methods for dredging. Dredged material would be routed to the DMPS via pipelines or barges. The DMPS would be diked, and dredge slurry would be allowed to settle and consolidate. Depending on the size of the DMPS and the

W912P724B0010 Amendment 1 l2pdrdjc Highlight

Mr. Marshall K. Harper 7 amount of material being dredged, the decant water could be released from the DMPS into the river. Effluent discharge from all DMPSs is done only with prior approval from the CVRWQCB in accordance with the 401 Water Quality Certification. Dredged spoils would be allowed to dry, and the land returned to prior uses except for Montezuma, where the dredged spoils would be used to create wetland habitat.

The CVRWQCB sets the standards for water quality within the Action Area. Dredging operations have to meet the water quality criteria and monitoring requirements described in the

Memorandum of Understanding between the United States Army Corps of Engineers, San

Francisco District and the California Regional Water Quality Control Board, Central Valley

Region, Concerning Operations and Maintenance Dredging of Stockton and Sacramento Deep

Water Ship Channels (MOU). The MOU requires water quality monitoring up and down current of the dredge, at the DMPSs, and at and up and down current of any discharge location back to the river from a DMPS. Water quality must be maintained and meet the turbidity and other criteria laid out in the MOU.

The quantity of material to be dredged each dredging season is expected to not exceed 500,000 cubic yards (cy), barring monumental flood events. Dredging is expected to operate 24 hours a day, seven days a week during the work window.

Hydraulic Cutterhead Pipeline

Hydraulic dredges remove and transport sediments by suction and pumping, which mixes large volumes of water with the sediment to form a slurry that is piped or barged to a disposal area. A hydraulic cutterhead pipeline dredge is a barge-type vessel that consists of an onboard pump(s), spud piles (long pipes), and a toothed cutterhead attached to a pipeline. The cutterhead is mounted to a ladder that can be lowered, raised, and angled to increase the dredge path. The discharge pipeline exits the back (stern) of the dredge. Flexible pipeline sections are added to the dredge’s pipeline opening, as needed, depending on the distance between the dredge site and the

DMPS. Approximately every 500 feet, the flexible pipeline sections are anchored in the bottom of the channel using spud piles. Pipeline sections and anchors not in use would either be secured on a floating barge, capped and lashed together to float in the channel, or stored at the designated staging areas. Once the dredge is positioned, the pipeline and cutterhead would be lowered to the bottom of the channel. The cutterhead would then slowly start to rotate and break up sediment along the seafloor, continuing from side to side in a sweeping arc using the swing anchor. The dredge would move along the channel self-propelled or by tugboat, and a crew would always maintain and operate the dredging equipment. Skiffs and a tugboat would be used for crew transport, maintenance, and other operations associated with dredging activities. The collected dredge slurry is expected to consist of 80 to 90 percent water and 10 to 20 percent solids by weight. This ratio is ultimately determined by the difficulty of material removal experienced by the dredge operator.

When the dredge is positioned in a location where shoaling is to be removed, the dredge anchors itself by alternatively planting one or two “spuds,” or vertical poles, into the bottom sediment.

The dredge rotates around whichever of the two spuds is planted by pulling on “swing” anchors, alternately raising and planting the spud as the dredge “walks” forward. The hydraulic pipeline

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Mr. Marshall K. Harper 8 cutterhead dredge is equipped with a rotating cutterhead (excavator) surrounding the intake of the suction line. At that point, the solids and a large volume of the surrounding water are passed through the dredge centrifugal pump to the discharge pipeline as slurry.

Dredging activities would be limited to depths greater than 25 feet, and the cutterhead would be kept within three feet of the channel bottom while drawing in water. The cutterhead is mounted on a “ladder” that is free to pivot in the vertical plane and rotated down to various depths. The ladder would be mounted on a floating dredge that swings left and right while proceeding along the channel. The dredge could be self-propelled or transported to the area by a tugboat.

Typically, the dredge is tended by two tenders that pick up and place the swing anchors as the dredge progresses and can move the dredge short distances. There are also two outboard engine-powered skiffs that transport crews and conduct water sampling upstream and downstream of the dredge.

Mechanical Clamshell

A mechanical clamshell dredge consists of a crane mounted on a floating deck barge, with a clamshell bucket on the end of the crane boom. The deck barge has two to four spud piles attached to the platform, generally at the corners. The spud piles are long pipes that would be driven vertically into the SDWSC bottom by hydraulic assistance. The spud piles are used to anchor the dredge barge. Clamshell dredges are not self-propelled, so they require a tugboat to tow or push the dredge to and from the dredge sites. Once a tug moves the dredge into place, the spuds are driven into the bay bottom anchoring the dredge. Once the dredge is anchored in place, dredging can begin. Relocating the dredge would require approximately one hour to complete.

On average, the mechanical clamshell dredge plant for this project would need to be relocated approximately every three hours. In addition, when working in the ship channel, the dredge would need to be moved out of the shipping channel to allow deep draft vessels to transit the channel.

The crane would be equipped with a boom that is long enough to extend out beyond the end of the work barge in any direction and is able to swivel 360 degrees on its mount. A large clamshell bucket would be attached to the end of a series of cables at the end of the boom, which would allow the bucket to be raised and lowered into the water. The cables would open and close the bucket as it is filled with sediment and then emptied into scows. Scows are open barges that can carry large quantities of sediment and are towed with tugboats to and from disposal sites. As soon as one scow is filled and hauled away, another empty scow would be maneuvered into place alongside the dredge and digging would continue.

Clamshell buckets would be raised and lowered to the bottom of the SDWSC using a system of cables. The weight of the bucket would be sufficient for it to fall through the water column into the bottom sediment. Cables would restrict the clamshell from going too deep, or beyond the maximum allowable overdepth. During mechanical dredging, the clamshell would close and be pulled up through the water column to above the scow. Once over the scow, the clamshell would open and deposit the dredged material into the scow. The bucket’s full cycle would take approximately 75 seconds from entry into the water column, capturing sediment in the bucket, raising in the water column, and dropping sediment into the scow; for approximately 25 seconds

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Mr. Marshall K. Harper 9 of the cycle the bucket would be below water. When all the material within reach of the clamshell is dredged, the spuds would be raised, and the tender tug would transport the dredge and scow to the next area requiring dredging. The process would be repeated until all material is dredged from the channel. Following dredging, hydrographic surveys would be conducted to ensure that the entire area is dredged to the desired depth.

During dredging, clamshells would place a slurry of sediment and water in the scows. Depending on the sediment type being dredged, the sediment-to-water ratio of the slurry is expected to be approximately 60 to 70 percent sediment and 30 to 40 percent water. To increase the sediment volume in the scows, the scows may decant water back to the water column in a process called overflow. Overflowing the scows increases the sediment volume, compared to water, which can decrease the number of scow-tug trips to placement sites, thereby decreasing construction costs.

Turbidity monitoring would be conducted within 500 feet of dredging operations to demonstrate that the turbidity plume generated by overflow activities meet the turbidity and other criteria laid out in the MOU.

Based on prior dredging seasons, most of the dredge material within the SDWSC is comprised of sand and silt, which settles within a couple of hours. Based on 30 samples, 24 had sediment that was greater than 80 percent sand (Corps 2021). One of the samples with higher silt and clay content in the sediment sample was near Mandeville Island, the other five samples were further upriver past where the White Slough enters the San Joaquin River near Vulcan Island (Corps

2021).

For the proposed project, the clamshell bucket capacity would range between 20 to 50 cy, depending on dredge availability. Up to seven scows, with a capacity of 2,000 to 4,000 cy, and up to four 1,800-horsepower (hp) tugs would be used to transport dredged material to placement sites. In addition, one 1,000 hp tender tug would be required to maneuver each dredge plant.

The estimated daily production rate would range between 3,000 and 7,000 cy, depending on the location of dredging and the DMPS being used. For example, the production rate would be approximately 5,000 cy if a nearby DMPS was available, while the production rate would decrease if material would have to be transported further.

Dredge Material Transport and Placement

For hydraulic cutterhead dredging, the dredge material would be transported to the DMPS via discharge pipes. Mechanical dredging would use scows to transport the dredged material to the

DMPS.

Scows transported to the DMPS would moor to an offloader at the respective site, such that sediment could be pumped out of the scow and onto the restoration site. The dredged material would be pumped out using a modified hydraulic pipe dredge, which serves as an offloader. A

Liberty offloader, which is on a floating barge or a land-based offloader could be used. Once moored, the offloader would insert a snorkel into the scow, simultaneously injecting water into the scow to create a water-sediment slurry and pumping the slurry from the scow to a designated cell within the site. The offloader's water intake system must be screened in accordance with the

CDFW's screening criteria. It would take approximately two hours to completely offload dredged

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Mr. Marshall K. Harper 10 sediment from a scow. Scows-tugs would travel an average of 20 miles to the DMPS. Scows-tugs would travel approximately 7 knots (8 miles per hour) from dredge sites to the DMPS. On average, each scow-tug trip to and from the beneficial use sites, including offloading, would take approximately 1-3 hours.

The discharge pipeline would run from the dredge in the channel, across the bank, and onto the relevant DMPS. At all DMPS, a nominal area of outboard levee would be temporarily disturbed during the positioning of the slurry pipe. To minimize disturbance, a survey would be taken of the area immediately prior to pipe placement, and upon completion of the dredging operation, any disturbed banks would be restored to pre-project conditions. All pipes would be placed so as to avoid affecting any listed species or habitat.

The pipeline would be made of durable plastic and would alternately float or sink depending on the specific gravity of the material it contains. The pipeline would float approximately 2 inches above the water surface when filled with water or air and would rest on the channel bottom while containing dredged material and water. Depending on which section is being dredged, the length of the pipeline could range from 1,500 to 22,000 feet. The dredge contractor would determine the best route for the pipeline (per the disposal plan) in conjunction with a qualified biologist to avoid special status species or habitat. The pipeline would be marked by buoys and/or high visibility paint to warn boaters of its presence. Additional safety measures may include signs, flaggers, and/or other measures as required.

Bank Protection

Suitable rock protection would be placed at eroded sites. Where scour, wash, settlement, or failure of a portion of the original stone protection has been noted, or where inspection indicates that such damage may result during the next flood or high water period, the scour or wash would be filled with earth that is free from brush, roots, sod, or other unsuitable material and additional stone would be placed upon the earth fill. Bank stabilization maintenance work would bring the rock protection to its original section, using rock fill, filter material, and quarry rock. To the extent practicable, the rock would be similar in kind and gradation.

Along reaches of the SDWSC where filter material was originally placed or where it may be required, maintenance repair of existing rock protection would include the placement of a properly graded filter layer under the rock protection. In the event an inspection reveals that due to scour, settlement or other causes, rock protection on the bank is required beyond the limits of the original construction, or in reaches of the bank not originally provided with such protection, the Corps will alter the slope to conform with standards by placing rock, as needed, to protect completed works.

Construction activities in shallow water habitats will be avoided to the fullest extent possible.

However, proposed maintenance bank stabilization work may involve some shallow water areas.

This maintenance bank protection work is located along both banks of the constructed portion of the SDWSC at various locations. Rock may be placed at any site that previously contained bank protection work or where there is a need for additional rock due to bank erosion. On the

SDWSC, the maintenance bank protection work would be located along the right and left banks, W912P724B0010

Mr. Marshall K. Harper 11 between River Mile 4.0 and 42.0. Authorized maintenance sites are within 1,000 feet of the

Stockton DWSC centerline.

The Corps will conduct bank protection maintenance during the work window from June 15 to

November 30 to avoid adverse effects to listed fish species in the project area, including delta smelt.

Fish entrainment and/or capture monitoring

Depending on the type of dredging conducted, the dredge contractor will employ one of the below listed fish entrainment/capture monitoring programs.

A fish entrainment monitoring program has been implemented to help quantify the level of incidental take of special status species from the dredging operations, assess the effects of maintenance dredging and dredge material placement on water quality, and provide feedback to the Corps to lessen potential environmental effects of the long-term dredging activities. This fish monitoring program has been ongoing since 2006 and has been utilizing adaptive management practices to improve the effectiveness of the monitoring. Part of the adaptive management has included the design of a fish entrainment device to allow more effective dredged material monitoring and further reduce adverse effects. Entrainment monitoring will be implemented during each dredging season unless otherwise noted by the Service, NMFS, and CDFW. Overall monitoring time will be increased to reach a goal of at least 30 percent of dredged material monitored during any given dredge season.

The protocol for entrainment monitoring is well-developed for use with a hydraulic cutterhead dredge; however, entrainment monitoring is less successful when conducting maintenance dredging utilizing a clamshell dredger. Accordingly, the Corps proposes to conduct experimental fish capture monitoring to identify a method which could be used to quantify take of special status fish and other organisms. Refinements to these protocols would occur through the adaptive management process through close coordination with the Service throughout the dredge season.

Since the variation in the material composition is unknown, and the variation in the benthic biota and fish captured is also unknown, the Corps is proposing to use grid sampling to gain an understanding of the level of variation in the material. Since the capacity of a standard scow is

5000 cubic yards, and the standard environmental bucket can transport 30 cubic yards, each scow can carry approximately 167 bucket loads. Thirty percent of this value, the target under the other protocol, is 50. Therefore, taking 50 samples of a full scow is intended to simulate taking a grab sample of 30 percent of the loads delivered to the scow. At this juncture, this sampling protocol will help the Corps understand the variation present in the medium and the organisms captured, while meeting targets similar to those under the hydraulic monitoring protocol. After variation is understood, the Corps, in coordination with NMFS will revise the protocol to determine a statistically significant number of samples to take per scow.

Mr. Marshall K. Harper 12

Scow Grab Sampling

1. Once a scow is full, visually divide the scow into 1-yard x 1-yard square grids.

Number each grid sequentially.

2. Utilizing a random number generator, select and identify 50 individual grid squares from the scow.

3. Utilizing another random number generator, assign a random depth to the nearest half-foot ranging from surface (0) to full depth (usually 8.5 feet) to each of the individual grid squares identified in the previous step.

4. Utilizing a grab sampler no smaller than 1 cubic foot in size, collect a sample of sediment from the scow for each of the individual grid squares identified.

5. Characterize the spoil material (e.g., sand, silt, or clay). Separate any incidentally collected organisms from other attendant material. Record any fish or invertebrates incidentally collected including all pertinent attributes documented under the hydraulic fish entrainment monitoring program.

6. Document all findings in the Biological Resources Monitoring Report.

Engineering Research and Design Center Fish Screen

The Corps Engineering Research and Design Center is currently in the process of designing a fish monitoring screen for use with mechanical dredgers which would function similarly to the fish entrainment monitoring device in use for hydraulic dredgers. To further this effort to quantify take of listed species in real time, maintenance dredging completed under this project would utilize the experimental device and provide reports to determine the feasibility of permanently including this monitoring measure.

Avoidance and Minimization Measures

The Corps is proposing to implement a number of general conservation measures such as standard Best Management Practices (BMPs) and other measures. Please refer to the project BA for these BMPs. The following conservation measures are specific with regard to the delta smelt, the longfin smelt, and the GGS.

Delta Smelt and Longfin Smelt

All dredging will be accomplished during an in-water work window from July 1 to November

30. A two-week extension to December 15 may be implemented upon concurrence by the

Service.

Dredging Operations-Related Avoidance and Minimization Measures:

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1. No dredging work will be conducted from land-based equipment.

2. Dredging at depths of less than 20 feet will be avoided to the maximum extent achievable.

3. Maintenance dredging will only be conducted in the authorized channel to the authorized depths.

4. The Corps will coordinate project dredging schedules and plans with the Service, NMFS, and CDFW with the intent of reducing and avoiding any adverse project effects to listed species and designated critical habitats to the extent feasible. In addition, a biological monitor will conduct pre-dredging, aquatic, and/or terrestrial pre-construction surveys prior to all maintenance dredging.

5. A maintenance dredging work window is proposed to follow a yearly schedule between July 1 through November 30 for the SDWSC. From July 1 through July 31, dredging on the SDWSC would only be permitted between the Roberts II DMPS and the Port of Stockton. A standard 2-week extension is also proposed, after concurrence with the Service, extending dredging in the Stockton DWSC to December 15, on a case-by-case basis. If any extension period beyond the traditional work window is granted, fish entrainment/capture monitoring shall be increased to 24/7 monitoring as fish are more likely to be present outside of the environmental work windows.

6. If two dredgers are used in a single channel, they will not operate in the same reach to reduce the length of channel that fish are exposed to elevated turbidity. Alternatively, if two dredgers are used in the same reach, a turbidity curtain must be used downstream of each dredger to reduce the length of channel that fish are exposed to elevated turbidity.

7. All slurry pipe placement and bank stabilization activities will specifically avoid known locations containing special status species and/or designated critical and other sensitive habitats to the maximum extent feasible.

8. The contractor will be responsible for providing erosion and sediment control measures in accordance with Federal, State, and local laws and regulations to ensure compliance with water quality standards. This will be accomplished by installing temporary and permanent erosion and sediment control best management practices.

These may include, but are not limited to, vegetation cover, stream bank stabilization, slope stabilization, silt fences, construction of terraces, interceptor channels, sediment traps, inlet and outfall protection, diversion channels, and sedimentation basins. Any temporary measures will be removed after the area has been stabilized.

9. A Corps representative will be identified as the point of contact for any contractor who might incidentally take a listed species. This point of contact will be identified to all construction employees during an orientation regarding the potential effects on listed species. The orientation will be conducted by a qualified biologist and cover

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Mr. Marshall K. Harper 14 specific information on measures to prevent injury to listed species and what to do if any are found in the project area.

10. Fish entrainment/capture monitoring will be conducted for all dredging work. The

Corps and its contractors will pursue a monitoring target of 30 percent of the material dredged in accordance with the procedures, unless operating outside of the environmental work window wherein the Corps and its contractors will attempt to monitor all dredged material for fish entrainment using a cutterhead dredge and will double the monitoring conducted if using clamshell.

Hydraulic dredging measures:

1. Cutterheads will not be operated more than 3 feet above the channel bottom.

2. Suction dredging will not be operated as the dredge head is deployed and retrieved through the water column.

3. The suction head will be maintained at a constant elevation near the channel bed when dredging, to reduce the field of influence where fish may be entrained into the dredge pipe.

4. A drag beam or similar device will not be used to “knock down” ridges or high spots on the channel bottom.

5. The cutterhead rotation speed would be reduced as needed to reduce the potential for side casting the excavated sediment away from the suction entrance and resuspending sediment.

6. The swing speed would be reduced as needed to ensure that the dredge head does not move through the cut faster than it can hydraulically pump the sediment. Reducing swing speed reduces the volume of resuspended sediment. The goal is to swing the dredge head at a speed that allows as much of the disturbed sediment as possible to be removed with the hydraulic flow. Typical swing speeds range from 5 to 30 feet per minute.

7. Bank undercutting will be eliminated, and sediment will be removed in maximum lifts equal to 80 percent or less of the cutterhead diameter.

8. The hydraulic dredge will operate on the bottom of the channel, and the velocity of water moving toward the dredge cutterhead will be less than 1 foot per second within

9 feet of the suction…