San Francisco District. U.S. Army Corps of Engineers

Transcription

1 San Francisco District U.S. Army Corps of Engineers Dredged Material Management Plan for the Sacramento River Deep Water Ship Channel (SRDWSC) Deepening Project Final March 2012 Sacramento River at Rio Vista Bridge, courtesy of DWR

2 Executive Summary In accordance with U.S. Army Corps of Engineers (USACE) guidance and Engineering Regulation dated April 2000, all federally maintained navigation projects must demonstrate that there is sufficient dredged material disposal capacity for a minimum of 20 years. A preliminary assessment is required for all Federal navigation projects to document the continued viability of the project and the availability of dredged material disposal capacity sufficient to accommodate 20 years of maintenance dredging. If the preliminary assessment determines that there is not sufficient capacity to accommodate maintenance dredging for the next 20 years, then a dredged material management study must be performed. USACE policy for developing and maintaining navigation projects is based on the following criteria. (a) Sound management of dredged material is a priority mission of the USACE. (b) The USACE is committed to conducting dredging and managing dredged material in an environmentally sound manner. (c) The interests of economic development and environmental sustainability will best be served when dredged material placement proceeds according to a management plan. Therefore each existing and proposed navigation project will have a dredged material management plan that ensures warranted and environmentally acceptable maintenance of the project. (d) Beneficial uses of dredged material are powerful tools for harmonizing environmental values and navigation purposes. It is the policy of the USACE that all dredged material management studies include an assessment of potential beneficial uses for environmental purposes including fish and wildlife habitat creation, ecosystem restoration and enhancement and/or hurricane and storm damage reduction. Districts and Major Subordinate Commands (Divisions) will make every effort to ensure that sponsors and other interests understand the valuable contributions that beneficial uses can make to management plans and will maximize use of regional forums to share experiences of opportunities for beneficial uses. (e) Dredged material management goals are to be achieved by District and Division Commanders within existing delegations of authority. Exceptions to this principal are when problems arise that are of such significance that HQUSACE or Administration commitment is required such as changes in dredged material management practices that require substantial capital investment. Dredged Material Management Plans (Management Plans) shall be prepared for all Federal navigation projects, or groups of inter-related harbor projects, or systems of inland waterway projects (or segments). (a) Priority will be given to projects for which existing dredged material disposal sites, including existing confined disposal facilities, are expected to reach capacity or to no longer be available sometime in the next 10 years, or i

3 (b) Existing and projected navigation usage of the project indicates that continued maintenance of the project, or of any substantial increment thereof, may not be warranted. (c) Management Plans shall identify specific measures necessary to manage the volume of material likely to be dredged over a twenty year period, from both construction and maintenance dredging of Federal channel and harbor projects. Non-Federal, permitted dredging within the related geographic area shall be considered in formulating Management Plans to the extent that disposal of material from these sources affects the size and capacity of disposal areas required for the Federal project(s). In those cases where two or more Federal projects are physically interrelated (e.g., harbors which share a common disposal area or a common channel) or are economically complementary, one Management Plan may encompass that group of projects. It is the USACE policy to accomplish the disposal of dredged material associated with the construction or maintenance dredging of navigation projects in the least costly manner. Disposal is to be consistent with sound engineering practice and meet all Federal environmental standards including the environmental standards established by Section 404 of the Clean Water Act of 1972 or Section 103 of the Marine Protection, Research and Sanctuaries Act of 1972, as amended. This constitutes the base disposal plan for the navigation purpose. Scope The Sacramento River Deep Water Ship Channel (SRDWSC) Deepening project proposes to deepen the Sacramento River, including the man-made ship channel and the Port of West Sacramento, from its existing depth of the 30-ft Mean Lower Low Water (MLLW) to the current authorized depth of 35-ft MLLW. This project does not consider the impacts, cumulative or otherwise, associated with the proposed project to deepen the San Francisco Bay to Stockton Deep Water Ship Channel project, which is currently in the planning phase. This report evaluates alternative placement sites for the approximately 9.8 million cubic yards of dredged material that will be removed from the project. An initial Placement Site Report (App. C) was developed to determine all of the potential placement sites that are currently available, or that may become available in the very near future, in the delta region and along the Sacramento River. Sites were selected based on available capacity, proximity to the project, as well as their location to potential reuse sites, such as flood control levee rehabilitation and repair sites. A selection criteria and rating system was developed to pare down the initial number of sites to those that are evaluated in this report. This report also discusses the preparation, operation, and management of the placement sites for the deepening project as well as for the future maintenance of the project. This report assumes that all dredging will be accomplished using a hydraulic cutter head dredge plant, and that all of the dredged material will be hydraulic pumped into the prescribed placement sites. Summary of Analysis Emphasis was placed on developing sites that provide the greatest beneficial use, and that were also environmentally sustainable in terms of providing capacity into the future for O&M material after the project is deepened. The placement sites also had to be comparatively economically feasible to construct and operate. Ten sites were selected to be the primary sites and an additional four sites were selected to serve as alternate sites in the event that any or all of the primary sites became unavailable ii

4 for this project. Five of the primary placement sites are considered as stockpile sites, and all but one of the alternate sites are considered as stock pile sites that could provide resources for beneficial use. This report addresses both the primary and alternate placement sites but, emphasis is placed on the primary sites. A Placement Site Optimization Analysis (App. D) for the SRDWSC project was performed to demonstrate that the primary plan could provide the necessary capacity for the estimated maximum volume of dredged material, for the proposed schedule for construction, and still meet all of the water quality requirements that are anticipated for this project. The Placement Site Optimization Analysis also analyzed the alternate sites, assuming that five of the beneficial use sites, Montezuma Wetland and the three sites that are operated by the Asta Corporation, from the primary plan were not used. The report also confirmed that the alternate sites provide the necessary capacity as well. It should be noted that if the alternate sites are used, the construction schedule can still be executed in the same projected 6-year schedule. This report discusses the management of dredged material associated with the deepening project and also discusses the management of future dredged maintenance material after the deepening project has been completed. Although the USACE requirement requires only a 20-year future sustainable capacity for maintenance material, this report also considers a 50-year sustainable capacity analysis. A cost comparison analysis was performed to maximize cost efficiency in terms of minimizing placement site construction costs by making extensive use of the available beneficial use sites. It is anticipated that the beneficial use sites, with the exception of Montezuma Wetland, will be harvested on an annual basis, which will create the necessary capacity for each year that a beneficial use site will be used. This cost to construct and operate a site was balanced with keeping the cost to dredge and place material in the beneficial use sites to a minimum by keeping the placement sites within a ten-mile pumping distance. The cost analysis demonstrates that not only do the beneficial use sites provide sufficient capacity for the deepening material; they also minimize associated site development costs because the sites can be reused indefinitely due to the annual harvesting of material. The beneficial use sites also become part of the solution to provide a cost effective, ready source of materials to be used in the local flood control levee rehabilitation and repair programs in the delta region. This Dredged Material Management Plan was developed with the intent to provide a plan that will maximize beneficial use of the dredged material from the deepening project as well as provide a plan for the future maintenance dredged material that is better environmentally than what is currently being done with the maintenance dredged material. As a result of the focused planning and design for the deepening project, approximately 50 percent of the deepening material will be placed in beneficial use sites. The same effort was applied to the long term maintenance planning effort. It is currently estimated that 50 percent of the future maintenance dredged material will also be placed in established beneficial use sites and the remaining 50 percent will, at a minimum, be made available for beneficial use purposes. The Port of West Sacramento has initiated their business plan to develop a soil processing facility, which will be located near the port in reach 5. This facility will not only generate revenue for the Port of West Sacramento but, it will also provide additional beneficial use capability to the project, and could result in 100 percent beneficial use of dredged material for the 50-year period of consideration. iii

5 Table of Contents Executive Summary.... i Scope.... i Summary of Analysis.....ii Table of Contents iv List of Appendices vi List of Figures... vi List of Tables vii 1.0 Project Description Project Authorization and Development History Dredged Material Placement Alternatives Dredged Material Management Plan SRDWSC Beneficial Use of Deepening Material Dredged Material Distribution for Deepening Material Montezuma Wetland Decker Island (S19) Asta Sites (McCormick, Deterding, and St. Francis) Dredged Material Distribution for Deepening Material Reach 1, S35, and Beneficial Use Site Montezuma Wetlands Reach 2, S20, S16, and Beneficial Use Sites S19 and Asta Reach 3, S Reach 4, S31-I, S31-II, and S31-III Reach 5, S4, and S Overview of the Timing, Duration, and Scheduling of the Proposed 35- foot MLLW..42 iv

6 5.3.1 Dredging Work Windows Summary of the SRDWSC Proposed Construction Schedule Dredged Material Site Preparation Dredged Material Placement Area Dredged Material Placement Existing Conditions O&M Dredging Future O&M Dredging v

7 Appendices A B - C Placement Site Plans (Included in Body of Report) CAD Sheets - Dredging Plans Placement and Beneficial Use Sites for the Sacramento River Deep Water Ship Channel Report Dated May 2010 D - Placement Site Optimization Analysis Report Dated Feb 2012 vi

8 List of Figures Figure 1.1- Sacramento River Deep Water Ship Channel Project Location...2 Figure Montezuma Wetland Habitat Features..13 Figure Montezuma Wetland Restoration Site...14 Figure Montezuma Wetland Phase I..15 Figure Decker Island (S19) Soil Conveyor System 17 Figure Decker Island (S19) Soil Conveyor System Figure Decker Island (S19) Soil Conveyor System Figure Decker Island (S19) Soil Offloading Facility Figure D.I. Aggregates Telecaster Figure Reach 1, Montezuma Wetlands and S Figure Reach 2, S20, S19, S16 and Asta Beneficial Use Sites.. 28 Figure Reach 3 and S14.33 Figure Reach 4, S31-I and S31-II...36 Figure Reach 4, S31-III...37 Figure Reach 5, S1 and S4..40 Figure Placement of Dredged Material Pipeline...52 Figure Discharge Point of Dredged Material Pipeline 53 vii

9 Figure Typical Berm Cross Section.54 List of Tables 3.1 Proposed Dredged Material Placement Site Details Dredging Volumes per Reach Under the Proposed Project Beneficial Use of Deepening Dredged Material Delta In-water Work Windows SRDWSC 35-Foot MLLW Proposed Schedule Summary of Construction at the Dredged Material Placement Sites Historic Maintenance Dredging of the SRDWSC Projected Yearly O&M Beneficial Use Capability Remaining Site Capacity After Deepening Dredged Material Placement...64 viii

10 1.0 Project Description The Sacramento River Deep Water Channel (SRDWC) is a federally authorized navigation project that begins at the mouth of the Sacramento River in Suisun Bay and progresses north through Cache Slough past the confluence with the Sacramento River, and then diverges from Cache Slough through the manmade channel and ends at the Port of West Sacramento (Port). The originally authorized project was deepened to a depth of 30-feet MLLW in 1963, and in 1969 Congress authorized funds to study deepening the 30-foot project to 35-feet MLLW. The SRDWSC has been divided into five separate reaches that were defined by their hydraulic characteristics as determined by historical shoaling patterns and average depths. Estimated volumes of dredged material were calculated using results from bathymetric surveys. The survey data were generated using single beam hydrographic equipment and the data was converted into channel cross-sections on 100-foot stations. The cross-section information, along with the proposed channel design template, was used in average end-area method calculations to generate estimated volumes for the purpose of cost estimating and informing the design of the associated disposal sites. These estimated volumes include two feet of overdepth tolerance and are broken down by project reach. This information is presented in Table 3.2 of this document. The 45.8-mile-long SRDWSC which passes through Solano, Contra Costa, Sacramento, and Yolo counties is located in the Sacramento San Joaquin River Delta (Delta). It provides deep draft navigation from New York Slough, near Collinsville, to the Port of West Sacramento. Besides the SRDWSC itself, the project footprint includes the surrounding waters from the William G. Stone locks, which is upstream of the Port, to approximately 1 mile downstream of river mile 0.0, where the start of dredging is proposed. The SRDWSC is located in the Sacramento West, Clarksburg, Saxon, Liberty Island, Courtland, Honker Bay, Rio Vista, Antioch North, Jersey Island, and Bouldin Island United States Geological Survey (USGS) 7.5-minute quadrangle maps (figure 1.1). The project footprint includes the SRDWSC and the surrounding waters, including the areas upstream of the Port to the William G. Stone locks and approximately two miles downstream of river mile 0.0, where the start of dredging is proposed. It includes all waters where potential changes in salinity may occur following deepening the SRDWSC, which include portions of the Delta from the confluence of the SRDWSC and San Joaquin River to Franks Tract. The project footprint also includes the banks of the SRDWSC and the dredged material placement sites, extending conservatively one-quarter mile away from the placement sites. The project location is shown on figure

11 Figure 1.1: Sacramento River Deep Water Ship Channel Project Location 2

12 2.0 Project Authorization and Development History The SRDWSC is located in the Sacramento-San Joaquin Delta region of northern California. The mile long channel lies within Contra Costa, Sacramento, Solano, and Yolo Counties and serves the marine terminal facilities at the Port of Sacramento. The Sacramento River Deepwater Ship Channel joins the 35-feet deep San Francisco Bay to Stockton (John F. Baldwin) Ship Channel at New York Slough, thereby affording access from the Port of Sacramento to the Bay area harbors and the Pacific Ocean. The southernmost 3.2 miles of the SRDWSC are naturally deeper than 35 feet and do not require dredging. The SRDWSC project extent is therefore 43.3 miles, starting at River Mile 0 by Collinsville and ending at River Mile 43.3 at the Port of Sacramento. The Sacramento River Deepwater Ship Channel was originally authorized by the River and Harbor Act (Public Law 525, 79th Congress, 2nd Session) and approved on July 24, Construction of a 30- foot deep channel was completed in In response to resolutions adopted on 10 July 1968 and 11 December 1969 by the House of Representatives Committee on Public Works, the Board of Engineers for Rivers and Harbors was requested to review reports pertinent to the Sacramento River Deepwater Ship Channel, and determine any modifications of the existing navigation project should be recommended. In July 1980, a combined Feasibility Report and Environmental Impact Statement (EIS) for Navigation and Related Purposes was completed recommending the widening and deepening to 35 feet of the existing channel. The final EIS was filed with the United States Environmental Protection Agency in May 1981 and the Chief of Engineers of the United States Army Corps of Engineers (USACE) approved the combined report in November The Feasibility Report was transmitted to Congress in October 1983, and the Sacramento River Deepwater Ship Channel, California, channel deepening project was subsequently authorized for construction by Public Law 99-88, dated 15 August This Authorization was superseded by Section 202(a) of Public Law (17 November 1986), of the Water Resources Development Act of 1986 (WRDA of 1986). A General Design Memorandum (GDM) and Supplemental Environmental Impact Statement was prepared in March 1986 which presented the selected plan for channel modifications between New York Slough and the Port of Sacramento. A supplement to the 1986 GDM was prepared in May 1988 in order to reduce the project costs. Construction of a 35-foot deep channel was initiated in 1989, but work was suspended in 1990 at the request of the Port of Sacramento (Port), due to unresolved issues between the Port and the local utility regarding gas pipeline relocations and the inability of the Port to continue financing their share of the project costs. Only two of the six construction contracts had been completed at that time, from River Mile 43.3 to

13 In its conference report on Bill Number HR 4060 in 1998 (to resolve differences between the House and Senate versions of the bill that became the Energy and Water Appropriations Act of 1999), Congress directed the USACE to complete a reevaluation of the un-constructed project that would serve as a basis for a possible recommendation to resume construction: The conferees direct the Corps of Engineers to complete a reevaluation report of the Sacramento River Deepwater Ship Channel, California, project using available funds. Negotiations were held between the Port of Sacramento and the Sacramento District of the USACE to develop an acceptable scope and budget for the project. At the at the request of the Port of Sacramento, however, USACE Management of the project was officially transferred from the Sacramento District (CESPK) to the San Francisco District (CESPN) in June 2002 and work was initiated on a cost-shared (75 Federal/25 Non-Federal) Limited Reevaluation Study in July 2002 with the Port s Board approval of the Initial Project Management Plan. The major engineering features (design) of the project are to remain essentially unchanged from the approved documents. Environmental considerations have, however, changed with new endangered species, availability of dredge material disposal sites, and heightened water quality, Delta LTMS planning, and SLR concerns, and a joint Supplemental Environmental Impact Statement/Subsequent Environmental Impact Report (SEIS/SEIR) will be prepared to accompany a Limited Reevaluation Report (LRR) for the study. As part of the study, a complete economic review will also be performed in order to confirm the justification of the project. In 2005 the Port of Sacramento requested that the study be suspended as the Port addressed its financial priorities. In 2007 the Port, in cooperation with the Port of Oakland, renewed its interest to again support the study and ultimately resume construction of the 35-foot channel as soon as possible. The San Francisco District received funds in late February 2008 and resumed work on the project in March

14 3.0 Dredged Material Placement Alternatives To accommodate dredging as required by the 35-Feet MLLW Project, a range of dredged material placement site options were identified in the study area, emphasizing beneficial reuse where practicable. To facilitate this evaluation, a study entitled Placement and Beneficial Use Sites for the Sacramento River Deep Water Ship Channel (hereafter referred to as the Placement Site Report ; USACE 2010f) was completed in May 2010 and is included as Appendix C. The Placement Site Report documents the options for placement of dredged material in the vicinity of the SRDWSC, including stockpile and beneficial reuse options. The report also describes engineering constraints, regulatory constraints, and estimated costs for acquiring and converting the sites for dredged material placement or reuse. Beneficial reuse refers to any use of the material that provides for some purpose other than disposal (ocean or landfill). Certain sites included in the Placement Site Report are existing placement sites used for annual maintenance dredging. The Placement Site Report identified 124 placement site options throughout an approximately 1,200- square-mile study area. Of these options, 68 were categorized as stockpile sites, 18 were categorized as reuse sites, and 38 were categorized as placement and reuse sites. Stockpile sites, as defined in the Placement Site Report, are; facilities that are designed to directly receive dredged material sediments and the accompanying water. These facilities are managed over several months to dewater the sediments enough to enable transportation of the sediments via truck or barge for subsequent beneficial reuse. Reuse sites are subdivided into two types; Reuse Only (R), and Placement and Reuse (PR) Sites. Reuse Only sites are defined as those beneficial reuse opportunities that can only be satisfied with the delivery of dry sediments. Placement and Reuse sites are defined as those beneficial reuse sites that can be designed to directly receive the discharge of water and sediment from the hydraulic dredging activity. While PR sites can also receive dry sediment, they provide the additional benefit of receiving material directly from the hydraulic dredge, which avoids the re-handling and transportation costs that accompany discharge to a stockpile. The Project Delivery Team decided that the focus would be to use as many of the strictly reuse use as possible to better meet the expectations for maximizing reuse. Once this decision was made, the reuse sites were evaluated on an estimated cost to use basis. These evaluation criteria included proximity to the river, logistical needs such as; where would the pipeline run, and the estimated capacity of these sites. It was decided that realistically a site could not be more than 10,000 feet from the river before logistics become an expensive issue. Therefore, the ultimate criteria for the final selection of the cadre of sites would include the sites closest to the river with the largest capacity, least amount of site prep, and closest to the portion of the river that would provide the dredged material. As soon as the estimated maximum capacity was reached as each new site was added to the cadre, then the selection process was complete. These final sites, primary and alternate, are described in Table 4 of Appendix C. For the purposes of this DMMP, 12 of the 18 remaining proposed placement sites were re-grouped to avoid the use of repetitive naming terminology. S1 consists of WS-P1 and WS-P2, S31 consists of S31-I, S31-II, and S31-III, and S35 consists of S35 and S35a. As such, the 12 placement sites evaluated in this DMMP 5

15 correspond to the 18 remaining sites as they were identified in the Placement Site Report, and also include the three Asta sites. The portions of each site that would be used for dredged material placement were identified based on 2008 and 2010 placement site vegetation and habitat surveys. Where possible, impacts to wetlands and other sensitive areas were avoided. The remaining areas are referred to as the usable portion of the placement site. Table 3.1 describes the 12 proposed placement sites that were carried forward for evaluation in this DMMP, including their approximate location along the SRDWSC, total area, usable portion, ownership, and recent use (within the past 15 years, or after 1995) for dredged material placement and reuse. 6

16 Table 3.1 Site Name Site Name as Defined in the Placement Site Report Proposed Primary & Alternate Dredged Material Placement Site Details Reach(es) within 15,400 Feet of Site Total Site Area (ac) MW-PR-1 MWRP Reach 1 1,800 1,500 S35 S20 S19 (Decker Island) S35 and S35a S20 Reaches 1 and 2 Reaches 1 and Site Usable Portion (ac) Site Owner Site Type DWR S19 Reach Montezuma Wetland, LLC GreenPort Energy Park D.I. Aggregate Management, LLC Reuse Stockpile Placement and Reuse Reuse S16 S16 Reach USACE Stockpile Yes S14 S14 Reach USACE Stockpile Yes ASTA McCormick Reach Private Reuse No ASTA Deterding Reach Private Reuse No ASTA S31 St. Francis S31, S31a Reach 2 and 3 Reaches 4 and 5 Used as a Maintenance Dredging Placement Site After 1995? a Notes: a While these sites have not been used recently as maintenance dredging placement sites, they were used as placement sites during the original SRDWSC construction, the two construction contracts carried out in 1989 and 1990, or for maintenance dredging occurring prior to b Anecdotal evidence from the property manager of site S20 indicates that dredged material was removed from the site in the past, possibly for beneficial reuse; however, specific details have not been confirmed. c This site was used for the Oakland Harbor -50-ft deepening project from 2004 through 2006, and is currently being used for maintenance dredging projects in San Francisco Bay. No c No a Yes b Yes 3 3 Private Reuse No 1, Port Stockpile Yes S4 S4 Reach Private Stockpile No a S1 WS-P1 and WS-P2 Reach Port Stockpile Yes 7

17 Table 3.1 correlate dredging locations and volumes under the Proposed 35-Feet MLLW Project with proposed placement sites. Table 3.2 provides the estimated volumes of dredged material in each reach, including the estimated volumes of overdepth for 1-foot and 2-foot increments. Table 3.2 Dredging Volumes Per Reach Under the Proposed Project (cy) Dredging Volume Required to Reach a Depth of 35 Feet Volume of 1- Foot Overdepth Total Dredging Volume including 2- Foot Overdepth Volume of 2- Reach Foot Overdepth 1 139, , , , ,599, ,000 1,278,000 3,877, ,000 37,000 91, , ,927, ,000 1,273,000 3,200, ,127, , ,000 1,879,000 Total 6,319,000 1,821,000 3,643,000 9,804,000 Note: Volumes (including totals) are rounded to the nearest 1,000 from more specific engineering values 8

18 4.0 Dredge Management Plan Topographic and bathymetric surveys that were taken in 2005 and 2009 coupled with the yearly average volumes of maintenance dredged material show that the remaining capacity for the total of all of the placements sites will be exhausted in less than ten years if material is not harvested from any of the primary sites including S19 (Decker Island), and the three Asta sites. The project sponsor (Port) is obligated by the terms of the 35-foot MLLW Project Local Cost-Share Agreement to ensure that the placement sites that were made available for the deepening will be maintained into the future to provide capacity for maintenance material for at least 20 years after the deepening project has been completed. To fulfill the Port s contractual obligation after the deepening, the Port can make arrangements to either clean out the placements sites or raise the existing containment berms to create additional capacity. It is currently anticipated that all of the remaining dredging will also be accomplished using hydraulic cutterhead dredge plants that will pump the slurried dredged material directly into the disposal sites located adjacent to, and all along the length of the river. It is also anticipated that it will become necessary to use booster pumps for portions of the project where the distance between the dredging areas and the placement sites is too far for the dredge plant to pump alone. The longest pumping distances are generally less than ten miles. All of the disposal sites were initially identified in the original Feasibility Study report and were then designed during the Pre-construction Engineering and Design phase of the project. The site designs were documented in the previous General Design Memorandum (GDM) in accordance with the latest USACE design guidance, for purposes of cost estimation only. In addition to the placement sites that were identified in the original GDM, the additional placement sites that were selected from the Placement Site report (App. C) for the deepening project as part of the current Limited Re-Evaluation Report (LRR) effort were also designed and evaluated for cost estimation purposes. As part of the re-evaluation of the project, a water quality report was prepared to determine if the assumed water quality standards that the project would be held to, could be met considering the dredging schedule, estimated amount of dredged material and the estimated capacities of the placement sites that would be used. After the draft SEIS/SEIR was issued for initial public comment in February 2011, several resource agencies expressed concern that there was no beneficial use of dredged material proposed for any of the placement sites. There has been a concerted effort to rectify this situation, and as of this point in the design of the project, there are several beneficial use sites that have been incorporated into the cadre of placement sites. All site prep construction activities will consist mainly of building up existing containment berms, or building new containment berms to a height that will provide sufficient capacity for the estimated dredged material volumes, and all of the estimated process water. The source for all of the soil needed to construct the containment berms will come from within the respective disposal sites themselves. All of the process water associated with hydraulic dredging will be decanted from each disposal site back into the Sacramento River once it meets the water quality criteria established by the State Central Valley Water Control Board. All dredged material that is placed in any of the identified disposal sites will be made available, at the discretion of the owners of each site, for commercial uses such as fill material, or 9

19 for future construction needs outside the immediate area. These needs might include levee construction or improvement in the Delta, future highway construction, or structural fill for commercial and industrial development. 10

20 5.0 SRDWSC Beneficial Use of Deepening Material The yearly deepening material from reaches 1, 2, 3, and a small amount from reach 4 will all be placed in sites where 100% of the material will be beneficially used. The remainder of the deepening material will be placed in placement sites that are currently not characterized as beneficial use sites but will be considered as stockpile sites. Of the total estimated 7,925,460 cubic yards of deepening dredged material that will be removed from the project footprint in reaches 1 through 4, approximately 5,024,776 will be beneficially used as shown in Table 5.1. Table 5.1 Beneficial Use of Deepening Dredged Material Placement Site Beneficial Use Reach 1 Reach 2 Reach 3 Reach 4 Total (CY) Type (CY) (CY) (CY) (CY) Montezuma Wetland 442, , ,260 Wetlands Restoration Decker Island Levee Repair & 0 3,468, , ,724,500 (S19) Rehabilitation Asta- Levee Repair & 0 96, , , ,510 McCormick Rehabilitation, & Construction Fill Asta-Deterding Levee Repair & 0 41,500 19,200 90, ,006 Rehabilitation, & Construction Fill Asta- St Francis Levee Repair & 0 29, , ,500 Pit Rehabilitation, & Construction Fill Total (CY) 442,460 3,877, , ,806 5,024,776 Total Deepening Volume (CY) 442,460 3,877, ,100 3,200,400 7,925, Beneficial Use Sites Montezuma Wetlands (Reuse): The Montezuma Wetlands Project (MWRP) (Figures 5.1.1, 5.1.2, and Sheet P1 of App. A) addresses two regional problems in the San Francisco Estuary: the loss of wetlands and the need for environmentally sound dredged sediment disposal options. This "beneficial reuse" project will restore over 1,800 acres of wetlands in the Suisun Marsh using approximately 20 million cubic yards of sediment dredged from the region's ports and waterways. Through restoration of a 11

21 complex wetland-upland ecosystem including seasonal wetlands, wetland-upland transition, freshwater drainages, and a 340-acre upland buffer surround the 1,800 acres of wetland; Montezuma will provide a tremendous regional boost to the protection and recovery of numerous wetland-dependent fish, wildlife, and plant species. Montezuma is the first privately sponsored wetland restoration in the nation. It is not compensatory mitigation for any mitigation; instead it derives its funding solely from dredged material placement. When completed, the restored wetlands will be protected in perpetuity. The MWRP has been receiving dredged material since 2004 and currently has capacity for 17 million cubic yards and is capable of receiving dredged material through its offloading system that is currently anchored adjacent to the site in the Sacramento River, or can receive dredged material pumped directly into any of the appropriate cells. The offloader system was built to offload scows that are hauled from various dredging projects within San Francisco Bay and the Sacramento Delta. The SRDWSC will be dredging using a hydraulic dredge and plans to bypass the offloading system and pump dredged material directly into the designated cells. 12

22 Figure Montezuma Wetland Habitat Features 13

23 Figure Montezuma Wetland Restoration Site 14

24

25 Figure 5.1.3: Montezuma Wetland Phase 1 15

26 5.1.2 Decker Island (S19)(Reuse): D.I. Aggregate Management currently operates a soil processing facility, commonly referred to as a pug mill on a portion of the Decker Island property (Sheet P4 of App. A). The purpose of the facility is to produce custom made soil that meets the specifications of the need. Soil is harvested from within the Decker Island property and mixed with other soils from other locations, such as clays or sands that are hauled to Decker Island by scow and offloaded by a telecastertype system. The soils are mixed on-site to the purchaser s specification and then loaded into scows using a conveyor system built specifically for this facility, and then hauled to the site where they will be used, or to a site where they can be offloaded using the same telecaster system, and then trucked to their final destination. Approximately 90% of the soils that are engineered at Decker Island are used for levee repair and rehabilitation. The remaining 10% of the soils are used as construction fill, landfill caps, and top soil for agricultural use. D.I. Aggregate Management is currently capable of producing approximately 900,000 cubic yards of material per year and is contracted to provide that amount of material for the next three years. They have stated that this yearly volume could be increased to 2.7 million cubic yards if needed. 16

27

28 Figure 5.2.1: Decker Island (S19) Soil Conveyor System 17

29 Figure 5.2.2: Decker Island (S19) Soil Conveyor System 18

30 Figure 5.2.3: Decker Island (S19) Soil Conveyor System Specially constructed scows or barges are loaded with the processed soils using the conveyor system. The soils are processed (mixed with other types of soils) to meet the specifications for the intended use, such as; levee repairs, construction fill, landfill capping material, etc. 19

31 Figure 5.2.4: Decker Island (S19) Soil Offloading Facility After the scows or barges have been filled, the soils are transported with the use of a tugboat to their intended location to be offloaded with a telecaster structure that is affixed to the scow or barge. 20

32 Figure 5.2.5: D.I. Aggregates Telecaster Once the tugboat has arrived at the prescribed destination, the scow or barge is positioned so that the soil can be removed from the scow or barge using the telecaster structure, and placed near the levees where the repairs will be affected. 21

33 5.1.3 Asta Sites (Reuse): The Asta sites, which include McCormick, Deterding, and the St Francis pit, provide a similar product as the D.I. Aggregate Management facility at Decker Island (Sheets P5, P7, and P8 of App. A). These sites are currently harvested for their existing soils and trucked to a pug mill to be mixed with other soils to create an engineered fill, or trucked to their final destination to be used as construction fill, landfill cap, or top soil for agricultural use. Asta currently is not involved with levee repairs and rehabilitation but has expressed an interest in doing so to grow their business, and as such, they would be in direct competition with D.I. Aggregate Management. Asta has harvested approximately 2 million cubic yards of material from their McCormick and Deterding sites since They are planning to use either the McCormick or Deterding site as the location for a future pug mill. The proximity of this future pug mill to the Sacramento River may make it possible to establish an offloading facility that is similar to the Decker Island system, for the purpose of hauling the engineered soil by scow instead of trucking the material to the intended destination. Asta is currently working to obtain permits for their enterprise and it is estimated that their facilities will be ready to receive dredged material by the time the deepening project is ready to place material in the Asta sites. 22

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35

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37 5.2 Dredged Material Distribution for Deepening Material Reach 1, S35, and Beneficial Use Site Montezuma Wetlands Reach 1 Reach 1 (figure 5.3 and Sheets C1 through C4 of App. B) begins at the end of the New York Slough Channel, near river mile -2.4, and ends northeast of Sherman Lake, at river mile 4.1, near Collinsville. Dredging this reach would begin at river mile 0.0, which is 2.4 miles east of the beginning of the channel and ends at river mile 4.1. As shown on figure 10 and sheets C1 through C4, several areas within this reach are at or below 35-feet MLLW and would not be dredged as part of the proposed project. It is expected that this reach would be deepened during the first year of construction within the proposed 6-month work window (June 1 through November 30). Approximately 442,500 cubic yards of sediment would be dredged from this reach. To the maximum extent feasible, all sediment dredged from reach 1 would be beneficially used at the existing Montezuma Wetlands Restoration Project during the first year of construction (year 1). Should Montezuma Wetlands either be partially available or not be able to accept dredged material, sediment would be placed at S35 or S20; however, if Montezuma Wetlands is available during the entire time this reach is dredged, S35 and S20 would not be used at all. The distance between Montezuma Wetlands and the areas that would be dredged in this reach ranges from approximately 0 to 4.1 miles. A 24-inch diameter hydraulic dredge can pump sediment approximately 3 miles before a booster pump is needed; ergo, one booster pump would be required to pump dredged sediment to the beneficial use site. The booster pump would be on a small barge floating in the river outside of the channel limits and would be anchored by spuds. The exact location of the booster pump would be determined by the dredging contractor at the time of construction. 23

38 Figure 5.3: Reach 1, Montezuma Wetlands and S35 24

39 Montezuma Wetlands Restoration Project (Primary) Montezuma Wetlands Restoration Project (figure 5.1 and Sheet P1 of App. A) is approximately 2,400 acres located at the eastern edge of Suisun Marsh at river mile 0.0, in Solano County, California. The purpose of this site is to restore approximately 1,820 acres of tidal and season wetlands, intertidal ponds, vernal pools, and upland buffer zone habitats. The site is deeply subsided and dredged material is used to raise site elevations such that wetland habitat could be restored. Montezuma Wetlands is a primary placement site that would beneficially use sediment from reach 1, between river miles 0.0 and 4.1, and reach 2, between river miles 4.1 and 4.8 during the first and second year of construction. Sediment placed at this site would be beneficially used for wetland restoration and would be used during the first of construction. This site would use up to 684,300 cubic yards of sediment from dredged from reaches 1 and 2. If this site is available for use, all 442,500 cubic yards of sediment dredged from reach 1 would be beneficially used at the site, and another 241,800 cubic yards of sediment dredged from reach 2 would also be beneficially used there. The cost to place additional dredged material beyond river mile 4.8 at the Montezuma site is greater than the cost to place that same volume of dredged material at the S19 site. An additional booster pump is needed beyond RM 4.8 to place material at Montezuma, which will increase the unit cost to the point where it is more expensive to place material at Montezuma than it is to place material at S19. Therefore, the only scenario where additional material might be placed at the Montezuma site is if S19 becomes unavailable for any extended period of time. The dredged material pipeline would pump directly into the appropriate cells, as directed by the Montezuma Wetlands managers, and would access the site at a point located at the lower southeast corner of the site. The pipeline would bypass the existing offloading facility, thereby saving cost associated with the use of the offloader facility, and pump dredged material directly into the designated cells. Once dredged material is pumped into the Montezuma Wetlands site, the responsibility for water quality and sediment management belongs to the MWRP site and not to the SRDWSC project. Montezuma Wetlands is permitted to accept dredged sediment from dredging projects. Permitting under the ESA was completed on September 24, Montezuma Wetlands Restoration Project s permits are available at: 25

40

41 S35 (Alternate) S35 is located in reach 1, approximately 3 miles east of Collinsville between river miles 2.0 and 3.1 along the north bank of the Sacramento River in Solano County (figure 5.3 and Sheet P2 of App. A). S35 is an alternate dredged material placement site for reach 1, only if Montezuma Wetlands were not available. Placement of maintenance material dredged from the SRDWSC at S35 was approved by the Central Valley Regional Water Quality Control Board (Central Valley RWQCB) in the maintenance dredging Waste Discharge Permit (WRD) General Order No (Central Valley RWQCB 2001, appendix V). S35 is owned by Green Port Energy Park. This site was previously used as a placement site for deepening material from reach 1 during the deepening project to achieve 30-feet MLLW, and still has all of the water control structures from its previous use but, currently only has capacity for an additional 30,000 cubic yards in the existing configuration. The site could accept up to 181,000 cubic yards of dredge sediment if existing containment berms were constructed to an elevation of 20.5 feet and an additional cell is constructed to the west and adjacent to the existing site. If Montezuma Wetlands is available, this site would not be used nor would any earthwork construction at this site occur. 26

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43 5.2.2 Reach 2, S20, S19, S16, and Asta Beneficial Use Sites Reach 2 Reach 2 (figure 5.4 and Sheets C4 through C14 of App. B) begins northeast of Sherman Lake, at river mile 4.1, and ends just north of the confluence of the SRDWSC and the Sacramento River, at river mile As shown on Sheets C4 through C14, nearly all of this reach would be dredged. It is expected that dredging this reach would occur in the first, second, and third years of construction during the proposed 6-month work window for this reach (June 1 through November 30). To attain a depth of 35-feet MLLW, approximately 3,877,400 million cubic yards of sediment would be dredged from this reach. Sediment dredged from reach 2 would be beneficially used at Montezuma Wetlands, S19, McCormick pit, Deterding pit, and St. Francis pit. If all sediment from this reach is beneficially used, approximately 241,800 cubic yards would be beneficially used at Montezuma Wetlands in year 1; 3,468,600 cubic yards at S19 in years 1, 2, and 3; and 96,500 cubic yards at the McCormick pit in year 3; 41,500 cubic yards at Deterding in year 3; and 29,000 cubic yards at St. Francis in year 3. It is anticipated that sediment would be harvested annually from the S19 site for beneficial use. This annual harvesting will provide for a yearly capacity of 2,470,000 cubic yards. Should all or a portion of these sites not be available while dredging this reach, then one or more of the alternative placement sites S19, S20, S16, and S14 would be used (S19 is both a primary and alternative placement site). Due to the distances of the placement sites from the dredging areas, up to three booster pumps would be required for placement at the McCormick pit and up to two booster pumps for placement at S19. The exact location of the booster pumps would be determined by the dredging contractor at the time of construction. 27

44 Figure 5.4: Reach 2, S20, S19, S16 and Asta Beneficial Use Sites 28

45 S20 (Alternate) S20 is located west of S35 from approximately river mile 5.0 to 5.2 on the east bank of the Sacramento River, in Sacramento County (figure 5.2 and Sheet P3 of App. A). The site is an alternate site that would only be used if Montezuma Wetlands were not available while dredging reaches 1 and 2. S20 was used for maintenance material in 2001 and The Department of Water Resources (DWR) owns this site. S20 has a capacity of approximately 568,000 cubic yards of dredged material if berms were constructed to an elevation of 26.8-feet. If this site is used then sediment dredged from reaches 1 and 2 will be placed here. If the primary placements sites are used to capacity, S20 would not be used. S19 (Decker Island)(Primary) S19 is located on Decker Island, between river miles 6.0 and 7.0 on the east bank of the Sacramento, River, in Sacramento County (figure 5.4 and Sheet P4 of App. A). The placement site area is owned by Milpitas Main Street Investment and the northern portion of Decker Island is owned by the CDFG. In 1999, the CDFG and Department of Water Resources began a wetland restoration and levee rehabilitation project in the northern portion of the island. The restoration site provides habitat to several listed and common species in the Delta region and is managed as a wildlife refuge. S19 was used for maintenance dredging in 2000, 2001, 2002, 2003, 2005, 2006, 2007, and D.I. Aggregate Management, LLC, currently harvests sediment from the borrow pits at S19 and beneficially uses it for levee construction and repair. D.I. Aggregates has contracts in place for the next two years to provide approximately 900,000 cubic yards of soil to various customers, for beneficial use. Many types of soil are placed at the Decker Island facility in order to be mixed with other soils to meet the requirements for specific purposes. As an example; soils that will be used for levee repairs are mixed with clays to resist seepage, and sand and gravel to increase structural integrity. After the soils are dried and processed, they are then loaded onto a conveyor system (figures ) that will transfer the soils to a scow where they are loaded and then hauled by tug boat to their final destination for use in levee repair and rehabilitation. S19 is a primary and alternative placement site and is considered a beneficial use site because sediment placed at the site would be harvested for use in levee construction and repair and as an aggregate for construction. S19 has a capacity of 2,470,000 cubic yards of dredged sediment that would be provided annually for sediment placement. An approximate total of 3,468,600 cubic yards of sediment dredged from reach 2 would be beneficially used at this site. Following each year of construction, dredged sediment would be harvested from this site to allow for additional placement. Placing sediment dredged from reach 2 would require up to two booster pumps, whose locations would be determined at the time of construction. S16 (Alternate) S16 is located south of Rio Vista between river miles 9.5 and 11.0 on the west bank of the Sacramento River, in Solano County (figure 5.4 and sheet P6 of App. A). The site is owned by the USACE and is often used for placing maintenance material, e.g., 2000, 2003, 2006, and