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Monterey Bay
Regional Water Project Project Narrative
Supplement to California State Lands
Lease Application
Revised February 3, 2016
Submitted by:
An Oceanographic Solution to Produce Fresh Water Contact Information: Kim Adamson, General Manager 7532 Sandholdt Rd., Suite 6, Moss Landing, CA 95039 Phone: 831-632-0616 Email: [email protected]
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Table of Contents
LIST OF TABLES 4
LIST OF FIGURES 4
LIST OF APPENDICES 5
1. PROJECT SUMMARY 6
1.1 OVERVIEW 6 1.2 PROJECT BACKGROUND 9 1.2.1 REGIONAL WATER SUPPLY ISSUES 9 1.2.2 KEY PROJECT CONSIDERATIONS AND FEATURES 9 1.3 APPLICANT’S OBJECTIVES 11 1.4 PROJECT SETTING 14 1.4.1 EXISTING SETTING 14 1.4.2 ENVIRONMENTAL SETTING 18 1.5 SITE DEVELOPMENT PLAN 19 1.5.1 SITE PLAN 19 1.5.2 SITE INFRASTRUCTURE 20 1.6 ALTERNATIVE LOCATIONS CONSIDERED 23 1.7 REQUIRED PERMITS 23 1.8 CONSTRUCTION PLAN 25
2. SEAWATER REVERSE OSMOSIS PROJECT OVERVIEW 25
2.1 MAJOR SWRO PROJECT COMPONENTS 26 2.2 ENVIRONMENTAL FEATURES 27 2.3 INTAKE AND DISCHARGE SYSTEM OVERVIEW 30 2.3.1 INTAKE 33 2.3.2 INTAKE STRUCTURE 35 2.3.3 ALTERNATIVES TO SCREENED DEEPWATER OCEAN INTAKE 37 2.3.4 MARINE BIOLOGICAL IMPACTS 40 2.4 SEAWATER CONVEYANCE FROM DESALINATION PLANT TO ONSHORE PUMP STATION AND OFF-SHORE
INTAKE STRUCTURE 41 2.4.1 OFFSHORE CONVEYANCE CONSTRUCTION 41 2.5 ONSHORE PUMP STATION AND DATA CENTER BOOSTER PUMP STATION 44 2.6 HEAT TRANSFER PROCESS 49 2.7 REVERSE OSMOSIS DESALINATION SYSTEM 49 2.7.1 SWRO PRETREATMENT SYSTEM 50 2.7.2 REVERSE OSMOSIS DESALINATION 51 2.7.3 ENERGY RECOVERY 52 2.7.4 PERMEATE POST-TREATMENT: DISINFECTION AND STABILIZATION 52 2.7.5 FINAL PRODUCT WATER STORAGE AND HIGH-SERVICE PUMP STATION 53 2.8 BRINE CONCENTRATE DISCHARGE 53 2.8.1 REGULATORY CONSIDERATIONS 54 2.8.2 DESIGN 55 2.8.3 DISCHARGE PLUME MODELING 56 2.9 OPERATIONS AND MAINTENANCE 56 2.9.1 CHEMICAL STORAGE AND USE 58
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2.9.2 STAFFING 59 2.9.3 SOLID WASTE GENERATION 59 2.9.4 ELECTRICAL POWER CONSUMPTION 59 2.10 PRODUCT WATER DISTRIBUTION PIPELINES 60 2.10.1 MONTEREY PENINSULA 60 2.10.2 CASTROVILLE AND SALINAS 60 2.10.3 SANTA CRUZ COUNTY 60
3. DATA CENTER OVERVIEW 65
3.1 MAJOR PROJECT COMPONENTS 65 3.1.1 DATA CENTER BUILDINGS 65 3.1.2 CLOSED LOOP COOLING SYSTEM 65 3.1.3 BACK-UP POWER SUPPLY 66 3.1.4 FIBER OPTIC INTERCONNECTIONS 67 3.2 OVERVIEW OF OPERATIONS 69 3.2.1 BUILDING EFFICIENCY 69 3.2.2 STAFFING 70 3.2.3 WATER USE AND WASTEWATER GENERATION 70 3.2.4 SOLID WASTE GENERATION 71
4. HYDROACOUSTIC MONITORING SYSTEM 71
4.1 HYDROACOUSTIC SYSTEM OVERVIEW 71 4.2 DYNEGY MOSS LANDING FUEL PIPELINE AND INSTALLATION OF THE HAIL SYSTEM 72 4.3 OPERATIONS AND MAINTENANCE 73
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List of Tables Table 2.1 MBRWP design flows for seawater and potable water
Table 2.2 Summary of environmental design, construction and operational features
Table 2.3 Locations of Intake and Discharge Structures
Table 2.4 Summary of maintenance operations
Table 2.5 Chemicals used on SWRO process
List of Figures Figure 1.1 Regional location map
Figure 1.2 Aerial photograph of former tank farm
Figure 1.3 Routing for potable water and sanitary sewer service
Figure 2.1 Proposed Intake and Discharge Pipeline Alignment and Pump Station
Figure 2.2 Secondary Alternative Intake and Discharge Pipeline Alignments and Pump Station
Figure 2.3 Northern Alternative Intake and Discharge Pipeline Alignments and Pump Station
Figure 2.4 Intake and Discharge Site Locations
Figure 2.5 Conceptual Intake Structure
Figure 2.6 Passive engineered intake screen assembly
Figure 2.7 HDD Intake and Discharge Pipeline Relative to Entry Pit for Proposed Option
Figure 2.8 Depiction of HDD Pipeline Installation
Figure 2.9 Conceptual Pump Station Design (Proposed, Site Plan)
Figure 2.10 Conceptual Pump Station Design (Proposed, Plan View, Motor Room)
Figure 2.11 Conceptual Pump Station Design (Proposed, Elevation)
Figure 2.12 Conceptual Diffuser Structure
Figure 2.13 Pipeline route map to Monterey Peninsula
Figure 2.14 Pipeline route map to Castroville and Salinas
Figure 2.15 Pipeline route map to Santa Cruz County
Figure 3.1 Fiber optic routing maps
Figure 4.1 Moss Landing Project Area Site Map for HAIL monitoring System
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List of Appendices Appendix A Biological Resources Report
Appendix B B1- Hydrogeological Literature Review and Analysis
B2-Potential GHG Release from Subsurface Desal Feeds
Appendix C Moss Landing Desalination Plant Intake Impact Assessment
Appendix D D1- Preliminary Design of the Ocean Intake and Discharge Pipelines for the MBRWP
D2- Alternative Pump Station Drawings (Ashley Vance, 2016)
D3- Intake and Outfall Conceptual Design and Construction Analysis (Forthcoming)
Appendix E E1- Pipeline Inspection Report -Moss Landing Power Plant
E2 – DWD Moss Landing Hydroacoustic Monitoring System
Appendix F Brine Dilution Analysis for DeepWater Desal
Appendix G Comparative GHG Emissions Analysis
Appendix H Wedgewire Screen Entrainment Study
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1. Project Summary
1.1 Overview Deepwater Desal LLC (DWD) is developing the Monterey Bay Regional Water Project (MBRWP or the Project) at Moss Landing, California. The MBRWP will consist of a proposed seawater reverse osmosis (SWRO) desalination facility, co-located seawater-cooled computer data centers, back-up power generation, and real time water quality data collection infrastructure. The proposed Project will be capable of producing up to 25,000 acre-feet of high quality potable water annually. As detailed in subsequent sections, seawater desalination has been recognized as an important component of the overall regional approach to addressing water supply for the Monterey Bay region. The volume of water produced at the proposed facility, and its central location within the region, make it an ideal solution to augment potable water supplies available in the region. The Project is intended to make a new supply of potable water available north to Santa Cruz, east to Salinas, and south to the Monterey Peninsula. The proposed SWRO facility will be co-located with a proposed 150-megawatt (MW) data center campus. Seawater will be used to provide cooling for the data center buildings prior to desalination. The seawater will capture waste heat from the buildings before entering the desalination facility. Seawater cooling of the data centers will make them among the most energy efficient data centers in the world. Seawater warmed by waste heat taken from the data center and power generation facilities will reduce the energy required to operate the SWRO desalination facility. The reduction in greenhouse gas (GHG) emissions for the co-located facilities is significant in comparison to standalone alternatives. The volume of power necessary to operate the proposed MBRWP, robust Project infrastructure and the Project’s proximity to major elements of the State’s electrical grid will afford the opportunity to supply electrical power necessary to operate the MBRWP at carbon intensities and financial cost significantly below what would otherwise be possible in the region. The proposed data center campus is a key part of the infrastructure necessary to meet the currently underserved data transmission and storage capabilities in the region. The proposed MBRWP will be located on a 110-acre site historically used to store heavy fuel oil used for generation of electrical power at the Moss Landing Power Plant. The site is designated for heavy industrial use in the Monterey County Local Coastal Plan. The site is located on the north side of Dolan Road, approximately 1.5 miles east of State Route 1 (SR1) at Moss Landing in Monterey County, California. The location of the proposed Project affords access to seawater from the Monterey submarine canyon. Seawater intake pipelines will be installed from the plant site, down Dolan Road, to a dry well just east of the intersection with SR-1. From that location, 42 in-dia. steel pipe will be installed using Horizontal Directional Drilling under SR-1, Moss Landing Harbor, the sand spit and Monterey Bay to a location on the east canyon wall.
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Brine discharge lines will extend to a location on the north shelf of the Canyon head. Proposed potable water distribution mains will be constructed running north from the MBRWP towards Soquel, east through Castroville towards Salinas, and south towards Seaside. The project location is show in Figure 1.1. The proposed desalination facility component of the MBRWP will address the urgent demand for additional supplies of potable water throughout the region with significantly lower impact on the area’s fragile environment than the cumulative impacts of multiple desalination facilities scattered around Monterey Bay. The proposed data center component of the MBRWP will significantly reduce the environmental impact and cost of operation of a standalone desalination facility while serving currently unmet need for data storage and transmission capability throughout the Central Coast region.
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Figure 1.1 Project Location
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1.2 Project Background
1.2.1 Regional Water Supply Issues The Monterey Bay region’s municipal water supplies come largely from a combination of groundwater and diversion of local rivers and streams. There is relatively little storage capacity for surface waters. Historically, several proposals to add storage capacity have been dropped due to concerns about impacts on the area’s fragile environment. Overdrafting of groundwater supplies has resulted in seawater intrusion as far inland as wells serving the City of Salinas. Steelhead trout, amphibians and other species that require consistent surface water flows to propagate and survive have all suffered from the diversion of river waters to meet the demands of residents, agriculture and other industries and businesses around Monterey Bay, as well as the overdrafting of groundwater that reduces base flows. The lack of sustainable water supplies from existing ground and surface water sources renders the region particularly vulnerable in times of drought. Finally, recent regulatory actions intended to reduce impacts on surface and ground water sources will reduce the available supply of potable water in some areas around Monterey Bay (notably the Monterey Peninsula, Salinas Valley Basin and Soquel Basin) to levels far below the amount of water necessary sustain the existing population.
1.2.2 Key Project Considerations and Features
1.2.2.1 Location Moss Landing Harbor is located at the head of the Monterey Submarine Canyon, one of the deepest and closest-to-shore submarine canyons in the world. The MBRWP proposes to use a screened, low velocity, deep water ocean intake located on the uppermost eastern slope of the Monterey Submarine Canyon. The intake structure will be deployed at the terminus of a newly constructed subsurface water conveyance pipeline located approximately 1,000 feet offshore and a depth of approximately 130 feet below the surface. At this sufficient depth, deep water from within the Canyon is driven up by tide-like oceanographic features and made accessible to the intake in the Canyon. This deep water contains low concentrations of planktonic organisms. The consistency and quality (low turbidity) of the intake water will also reduce pretreatment requirements for the feed water used in desalination facility and extend the operating life of the membranes used in the SWRO process. Independent studies completed on behalf of the MBRWP have confirmed that fewer aquatic organisms, such as larval fish, exist in the water column at the depth of the proposed intake location. As further discussed in Section 2.3.3, the location of the seawater intake facilities in the Monterey Submarine Canyon will reduce the Project’s impact on marine organisms to an insignificant level.
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1.2.2.2 Seawater Reverse Osmosis Desalination The proposed SWRO will be designed to produce up to 25,000 acre-feet per year (AFY) of potable water from approximately 55,000 AFY of seawater. Source water for the SWRO will flow from the offshore intake structure via subsurface pipes to a dry well pump station located onshore near the Moss Landing Power Plant on Dolan Road. Two 42-inch diameter pipelines will be installed beneath the ocean floor using horizontal directional drilling technology to connect the intake structure with the pump station. Pumps located in the pump station will pump the source water through two 36-inch diameter pipelines that will be installed under Dolan Road from the proposed pump station to the MBRWP site along the defined onshore pipeline route, as further described in Section 2.0. The SWRO will generate approximately 30,000 AFY of concentrate, or brine, which is proposed to be discharged through redundant 36-inch diameter pipelines to be constructed subsurface and fitted with high pressure diffusers (See Section 2.7 for additional information). At the terminus of the concentrate line in Monterey Bay, the concentrate will be discharged through a series of diffusers designed to rapidly mix the concentrate with ocean water at the point of discharge and minimize zones of hyper saline water in the discharge region. DWD has retained an independent consulting firm to design and model concentrate discharge using a series of duckbill high velocity diffusers. Sophisticated modeling shows the design will meet all regulatory requirements with respect to the Ocean Plan Amendment, while also meeting the requirements of the California Thermal Plan. The report in Appendix F is currently being modified to show this through additional modeling.
1.2.2.4 Data Center Facility Cooling Data centers have relatively modest environmental impacts, including low requirements for staffing. However, data centers require significant energy to keep computer servers and associated equipment cool. Typical data centers use chilled water systems to remove heat that builds up in the computer server rooms and ultimately reject it to the atmosphere using freshwater cooling towers. These systems require substantial electrical power to run the chillers and consume freshwater used in the evaporative cooling towers. In lieu of chillers and evaporative cooling systems, the MBRWP proposes to use the cold, SWRO source water to cool the data center buildings. The buildings will be cooled using closed-loop cooling systems that will transfer waste heat to the seawater through non-contact heat exchangers. Cooling the 150 MW of data center will increase the temperature of the SWRO feed water by approximately twenty degrees centigrade. The increased temperature of the source water reduces the energy needed to pump the seawater through the reverse osmosis membranes, while concurrently reducing the power required to cool the data center, thereby reducing the footprint of GHG emissions.
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1.3 Applicant’s Objectives Background: The objectives of the proposed MBRWP comply with the Monterey Bay National Marine Sanctuary (MBNMS) guidelines that encourage a single, regional desalination project, serving the Monterey Bay region, thereby avoiding the development of a number of small SWRO plants around the Bay. The regional impact of over-drafting the groundwater basins, rivers and tributaries that feed the bay and impact the steelhead and other species are priorities for MBNMS. This is an important factor when weighing the impact of a regional desalination operation. The MBRWP can provide the needed potable water for the Monterey Bay region, provide a drought reserve and enable reduced groundwater pumping and surface water diversion to promote habitat restoration. Potable Water: The MBRWP will produce enough replacement water to enable California American Water Company (CAW) to meet its obligations under the State Water Resources Control Board Cease and Desist order WR2009-060 95-10 and the final Court Order adjudicating the Seaside Basin. DWD understands that its MBRWP project is being considered as an alternative in the EIR prepared by the Public Utilities Commission for the proposed CAW desalination project. After a thorough evaluation process, the Monterey Peninsula Water Management District (MPWMD) has provided support for the scientific and environmental analysis of the MBRWP as a ‘back up’ project to supply up to 9,000 acre feet of water to the Monterey area on an annual basis should the CAW project not move forward for legal or technical reasons or be significantly delayed. MPWMD, through a Statement of Qualification selection process, has entered into a cost sharing agreement and memorandum of understanding (MOU) with DWD to have first right to water from the proposed plant as a contingency to the CAW project. California Water Company, the publically regulated utility company that provides water service to the City of Salinas is considering using 6,000 to 10,000 acre feet of potable water supplied from the MBRWP to augment its current Salinas Valley ground water sources which are threatened both by nitrates from surrounding farmlands and seawater intrusion. CalWater submitted a letter of interest to DWD in May2015. They are also a signatory to an MOU with Salinas through which Salinas would purchase wholesale power and sell it to the proposed MPWMD. CalWater is including the MBRWP in their 2015 Urban Water Management Plan as a potential supplemental water source. Soquel Creek Water District (SqCWD), who relies solely on an overdrafted ground water supply that has seawater intrusion at its coastline is also affected by hexavalent chromium, has identified the MBRWP as a potential source for the 1,500 acre feet of water it needs. Soquel Creek and the Monterey Peninsula Water Management District jointly commissioned an evaluation by Kennedy Jenks, an independent consulting engineer, of DWD’s MBRWP and its cost projections to deliver water to their respective Districts. The Kennedy Jenks evaluation concluded that DWD's projections were generally accurate. In May, 2015, SqCWD entered into
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a Memorandum of Interest with DWD. Soquel Creek Water District is including the MBRWP in their 2015 Urban Water Management Plan as a potential supplemental water source. The Castroville Community Services District (CCSD) whose service area lies between the MBRWP site and the City of Salinas has identified a need for 1,000 acre feet of water from the MBRWP. This need is in addition to any basin replacement water that may be generated and sold to Castroville by the CAW project. In September 2014, CCSD entered into a Memorandum of Interest with DWD. Pajaro/Sunny Mesa Community Services District (PSMCSD) who provides water in the Pajaro, Elkhorn, and Prunedale areas has identified a need for 1,000 acre feet of water from the MBRWP. In January 2015, the Board of PSMCSD entered into a Memorandum of Interest with DWD. The Marina Coast Water Management District whose service area includes the City of Marina and the former Fort Ord Military base in Monterey County is also considering desalination as a source of supply to augment its present ground water sources in the Salinas Valley. The 2012 Basin Management Plan Update prepared for the Pajaro Valley Water Management Agency concluded that up to 12,000 acre feet of water is needed in the Valley to replace ground water supplies threatened by seawater intrusion. Agriculture interests in the Valley believe that some, but not all, of that need could be eliminated through increased conservation efforts. Data Centers: Data centers are among the fastest growing businesses in the US and around the globe as companies race to meet the demand of the wireless world of communication through cell phones, PDA’s, laptops and other computer devices. Data centers are commonly referred to as the Cloud. They provide the physical infrastructure that enables technology to continue to support all forms of human needs for communications, personal transactions, record keeping, government applications and business/commerce competiveness. A data center is made up of computer servers that receive traffic and store electronic data for people, business and government that can be retrieved by those utilizing the internet. The proposed 150 megawatt data center campus will provide numerous regional benefits. There are no data centers in the Monterey Bay region. The closest data centers are located in Silicon Valley. The Monterey Bay region is underserved by the lack of broadband fiber infrastructure and data storage capability. The high tech industry refers to the lack of fiber infrastructure in an area like the Monterey Bay region as a cause for network “latency”. The proposed MBRWP project will address these issues, and more, through the development of a robust data center infrastructure supported by fully redundant broadband fiber connectivity. Several prominent technology and communications companies have expressed the need to reduce latency in the network between Northern and Southern California. The MBRWP will address those concerns by creation of an environmentally friendly data center campus located
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in the Monterey Bay region that will provide service at low cost relative to other data centers now located in California. Through a Memorandum of Understanding (MOU) with the City of Salinas, DWD has proposed an extension of this broadband fiber connectivity and associated data center infrastructure to support Salinas. These services would provide Salinas and the surrounding agricultural region with severely needed infrastructure required to remain competitive. To deal with the growing water costs and water shortages, growers are looking to next generation wireless soil sensing technologies to enable “Smart Farming”. These sensors will require significant wireless broadband access to be installed in the region, coupled with data center infrastructure, to upload data, interpret it, and ultimately relay messages back to the field with regard to water, nutrient, and overall soil management. The combination of data centers and high speed internet access (up to 50X faster than current available speeds in the region, where available at all today) will enable the region, its people, agriculture and tourism industries to access the benefits of technology at the level of Silicon Valley. As importantly, this infrastructure will allow Salinas to remain compliant with current FEMA requirements and ensure that local City, County, Police, Fire, Academic, and Hospital infrastructure is equipped with the needed redundant network connectivity and capacity to prevent catastrophic loss in the event of a local crisis or natural disaster. The synergistic efficiencies of the proposed MBRWP will lower the cost of desalinating seawater from Monterey Bay as well as the Power Utilization Equivalent (PUE) of its data center campus. Here are the high level objectives of the Project:
Develop a replacement water supply that would enable reduced groundwater pumping from severely over-stressed aquifers, reduce or reverse seawater intrusion, promote aquifer recharge and recovery, restore surface water base flows, and meet the requirements of the California Sustainable Groundwater Management Act (SGMA) of achieving statewide sustainability of groundwater supplies by 2040-2042.
Develop a local water supply that would enable reduced surface water diversion to promote habitat restoration.
Provide a regional approach for a supplemental water supply for the entire Monterey Bay region which, by serving multiple agencies and water users, promotes the efficient use of resources and infrastructure and avoids duplicative infrastructure cost and their associated environmental impacts.
Protect the regional economy and Monterey Bay communities from adverse consequences that result from mandatory curtailments under SGMA and due to periods of drought, which will result in highly restrictive mandatory conservation at consumption levels that will threaten businesses and jobs.
Provide a supplemental water supply that is readily available and reliable and avoids uncertainty and/or risks during project operations and/or maintenance.
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Provide the flexibility needed to efficiently and cost effectively meet future change conditions, including changes in demand, changes in regulatory requirements, changes in water quality, and climate change.
Provide a water supply that minimizes environmental impacts including but not limited to: energy requirements, greenhouse gas emissions, and adverse impacts to marine and coastal resources.
Provide a water supply that protects species in the ocean and coastal rivers, and promotes habitat restoration.
Develop a water supply in a timely manner that is relatively cost-effective in terms of both capital and operation/maintenance costs.
Enable businesses dependent on high speed internet services to locate in the region as well as enable a remote workforce to perform job functions without commuting to major urban centers.
Address data transmission latency issues on the central coast that prevent data intensive industries from locating in the region.
Utilize and repurpose an existing, abandoned oil pipeline in the Monterey Bay to be a non-intrusive, hydroacoustic monitoring system to collect real-time data for the MBRWP and other research/academia needs that may be of interest pertaining to the Monterey Bay Canyon.
1.4 Project Setting
1.4.1 Existing Setting
The SWRO plant and data center components of the MBRWP will be constructed on the southern portion of an approximately 110-acre site referred to as the East Tank Farm Parcel. The parcel is located on the north side of Dolan Road, approximately 1.5 miles east of the intersection of Dolan Road with CA State Highway 1.
1.4.1.1 Existing and Prior Land Uses
The project site was formerly owned by PG&E, who built five above-ground storage tanks on the site in the 1970s to augment the existing fuel oil storage capacity of the Moss Landing Power Plant (MLPP), which was originally built and operated by PG&E. The tanks were used to store #6 fuel oil; a heavy, high-paraffinic fuel. The MLPP ceased the use of fuel oil in the 1990s and the tanks were cleaned and removed in 2003, along with most of the associated piping and related equipment. An aerial photograph of the site when it had fuel oil tanks is shown in Figure 1.2. The site has been assessed for potential contamination and remediated as described further in Section 2.2.2. The site contains some remnants of equipment used as part of the tank farm, such as cleaned pipelines, and empty electrical cabinets. Many of the earthen berms that surrounded the fuel oil tanks remain in place. Following removal of the tanks and remediation of the underlying soil, much of the site was re-vegetated with native grasses. The present environmental conditions of the site are further discussed in Section 1.4.2.
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Figure 1.2 Aerial photograph of former tank farm
The site is unused with the exception of a small facility operated by the Marine Mammal Center (MMC) and used to stabilize rescued marine animals. Those facilities include a small trailer, a building and a one-million-gallon water tank that is used to store water for the Moss Landing Mutual Water Company that provides water to neighboring properties. The MMC facilities and water tank will initially remain on the site, however the tenants may have plans to move to another site in the region. Other uses on the Project site include several high voltage power transmission lines that connect to the Moss Landing Substation, and two large, underground natural gas pipelines that supply natural gas fuel to the MLPP. All of these gas and electric facilities run in a single corridor located in the northernmost 700 (approximate) feet of the Project site. The Project is surrounded by a mixture of other land uses. The dominant uses of the areas west of the Project site are active and historical heavy industrial uses. These include the MLPP (now owned and operated by Dynegy Moss Landing, LLC) that sits adjacent to the PG&E-owned Moss Landing substation and several auto dismantlers with associated salvage yards immediately to the East. On the south side of Dolan Road, near intersection of Hwy 1, is the former National Refractories plant, which produced magnesia and refractory brick, using seawater from the
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ocean and dolomite from the Natividad Quarry near Salinas. The site is now called the Moss Landing Industrial Park, and houses multiuse industrial tenants. Other uses surrounding the MBRWP include agriculture (both farming and cattle grazing) and undeveloped open space. There are three buildings that appear to be residences located within ¼ mile of the Project site boundary. The proposed seawater intake and brine concentrate discharge lines will extend west from the Project site using the pipeline corridor shown in Figure 2.1. Both the intake and concentrate discharge pipelines will be buried and will pass beneath CA State Hwy 1, through Moss Landing Harbor and terminate in Monterey Bay. Figure 2.1 also illustrates the proposed offshore pipeline routes. Moss Landing Harbor provides berths for research vessels, fishing boats, and a variety of smaller yachts and boats. The community of Moss Landing also has a historic village center that is host to a variety of small-scale commercial uses, and along its southern edge, Moss Landing has a small, stable residential community. The Monterey Bay Aquarium Research Institute and the Moss Landing Marine Laboratory form the anchor of marine research activities in Moss Landing and together with facilities at the University of California Santa Cruz and on the Monterey Peninsula make the Monterey Bay Area a world leader in marine research. Other linear facilities proposed for the Project include the product water pipelines to be used for delivery of potable water produced by the SWRO, and fiber optic cables that will connect the data centers facilities to existing fiber optic networks. These facilities are proposed to be located largely along existing linear corridors, such as public roads or railroad lines. Additional details on the siting of linear facilities can be found in Section 2 (for the SWRO) and Section 3 (for the data centers).
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1.4.1.2 General Plan Consistency and Zoning Monterey County 2010 General Plan The Monterey County General Plan contains countywide goals, objectives, policies, and the countywide land use plan. The General Plan is organized into four components: natural resources, environmental constraints, human resources, and county development. Each of these components addresses subject matter required for one or more of the mandatory general plan elements (land use, circulation, housing, open space, safety, conservation and noise). The General Plan also addresses parks and recreation, public services and facilities, historic preservation, demographics, socioeconomics, and air and water quality. In regard to industrial land use, it is the goal of Monterey County to encourage industrial development which maintains the quality of the environment and is economically beneficial to the area, located in close proximity to major transportation routes, and which are compatible with surrounding land uses. The MBRWP will help Monterey County achieve several goals listed in its General Plan. Those include: Chapter 1: General Land Use
Goal LU-1: Promote appropriate and orderly growth and development while protecting desirable existing land uses Goal LU-2: Encourage residential development of various types and densities for all income levels in areas where such development would be accessible to major employment centers and where adequate public services and facilities exist or may be provided. Goal LU-7: Encourage the use of the County’s major inland water bodies for multiple purposes, such as water supply, flood control, and hydroelectric generation.
Chapter 6.0 Public Services Element
Goal PS-2: Assure an adequate and safe water supply to meet the County’s current and long-term needs. Goal PS-3: Ensure that new development is assured of a long-term sustainable water supply
Chapter 7.0: Economic Development Element
Goal ED-1: Support the development of jobs and business opportunities in Monterey County Goal ED-2: Develop public/private partnerships among constituents, county, city, business organizations, and key industries to support economic growth within each of the key industry clusters.
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Goal ED-3: Create and maintain an adaptive/skilled workforce to meet the needs of existing and future businesses. Goal ED-4: Improve the business climate to retain and expand existing businesses of all sizes, recruit new businesses and support emerging industries (Source: Monterey County General Plan, 2010)
North County Land Use Plan The Coastal Zone in Monterey County is divided into four planning areas: North County, Big Sur, Carmel, and Del Monte Forest. The Project is located in the North County Land Use Plan area, which includes the unincorporated area of the Coastal Zone from the Marina City limits to the Santa Cruz County boundary at the Pajaro River, and inland nearly to Highway 101 to include as much as possible of the Elkhorn Slough watershed. The North County Land Use Plan was certified by the California Coastal Commission in 1982 as part of the Local Coastal Program for Monterey County. The plan identifies policies regarding natural resources management, the public service system, land use and development, and public access to the shoreline. A primary objective of the North County Land Use Plan is to plan for appropriate levels of land use and development in the coastal zone while protecting coastal resources and providing or maintaining coastal access and recreation opportunities. The plan states that the only industrial facilities particularly appropriate for North County are those that are coastal dependent. The MBRWP site is designated for Heavy Industrial Use in the North County Land Use Plan.
1.4.2 Environmental Setting Following demolition and removal of the fuel oil tanks and associated facilities, the Project site underwent remediation for historical soil contamination resulting from its prior industrial use. The remediation was performed by PG&E under contractual obligation and overseen by the California Department of Toxic Substances Control (DTSC) pursuant to California Health and Safety Code Section 25260 et seq. The remediation activities on the MBRWP parcel were part of PG&E’s site-wide remediation obligations, which include identified areas of the MLPP property, including the other former tank farm parcels located between the MBRWP site and the MLPP. In 2005, the DTSC issued a No Further Action letter in which they concluded that soil on the MBRWP site has been successfully remediated and historical activities had not affected groundwater quality beneath the site. The letter included a determination that no further soil removal or groundwater investigation was required. In April 2014, DTSC and Dynegy Moss Landing, LLC recorded a Land Use Covenant (LUC) imposing certain restrictions and requirements on the Project property related to the potential for future exposure to hazardous soil contaminants. The use of the property as a location for an industrial use like the MBRWP is allowed by the LUC without condition. The LUC requires preparation of a Soil Management
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Plan, which must be approved by the DTSC before any soil disturbing activities can be performed on the site. Following removal of the fuel oil tanks and associated equipment, a mixture of native and non-native vegetation has grown on the site. The heavily disturbed areas where the oil tank footings were located were seeded with native grasses. The undeveloped remainder of the site is largely non-native grassland, ruderal vegetation, and stands of Northern Coyote brush Scrub habitat and non-native trees. A biological resources survey was performed on most of the Project site in spring of 2013. The survey, performed by Denise Duffy and Associates, also included property along Dolan Road and the west side of SR-1 that would be included in, or near, the seawater intake and brine discharge pipeline route for the wet-well location and alternate pipeline routes along Dolan Road. A copy of the Biological Resources Report is provided in Appendix A. Additional biological and cultural resources are currently being collected and assessed by EMC Planning and WSA, Inc. This information will be forthcoming. As discussed in further detail in Section 2, the proposed intake and concentrate discharge pipelines will be constructed entirely subsurface. The installation of the pipelines will not involve disturbance of the seafloor except in the “breakout” locations in the vicinity of the intake and outfall structures on the shoulder of the Monterey Bay submarine canyon. The seafloor in the vicinity of the proposed intake and discharge locations consists of sandy bottom with little or no submerged aquatic vegetation. Details of the marine environmental setting are provided in Section 2.3.1.
1.5 Site Development Plan
1.5.1 Site Plan The proposed data center complex, SWRO buildings and power infrastructure will be located on the south side of the 110 acre parcel off Dolan Rd. The site plan will also include planned landscaping, berms, parking, drainage areas, roads, and other critical items planned for the site to meet architectural and code requirements. All areas of the site south of the PG&E transmission lines will be disturbed during construction. Additional site plan drawings will be submitted to the lead agencies in spring 2016.
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1.5.2 Site Infrastructure
1.5.2.1 Access and Ingress/Egress The main entrance for the Project site will be through the existing gate, located at the western terminus of Via Tanques Road near the intersection of Via Tanques and Dolan Roads.
1.5.2.2 Site Utilities
1.5.2.2.1 Project Substation The MBRWP will have significant electrical demands. The data centers will require up to 150 MW and the SWRO and other site infrastructure will require approximately an additional 25 MW of electrical power. The data centers derive commercial value in part from their ability to provide customers with mission-critical space to support their servers, including access to a steady stream of high-quality electrical power supply. Interruptions of power could lead to server damage or corruption of data stored on the servers. For this reason, data center installations require careful thought and planning with respect to redundant primary and backup power supplies. A critical characteristic of the MBRWP site is its proximity to the Moss Landing Substation, owned and operated by Pacific Gas and Electric Company (PG&E) and located about one mile west of the MBRWP site. In addition, several high voltage power lines run through a corridor located on the MBRWP property. To support the Project’s industrial uses, a redundant supply of electric power will be established by constructing a new project substation that is interconnected to PG&E’s transmission system through the adjacent high voltage power lines. The proposed interconnection and substation facilities will be designed to provide the redundant electrical power supply required to ensure power quality and reliability for data center operations. Exact configuration of the interconnection to PG&E’s transmission will be determined though a detailed electrical an interconnection study conducted by PG&E All of the new transmission structures will be built on the MBRWP site. Additional information will be provided with the substation/interconnection design to be submitted at a later date.
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1.5.2.2.2 Broadband Fiber Infrastructure In order to support the redundant network infrastructure needs of the proposed onsite data centers, DWD has entered into an exclusive relationship with a provider of broadband fiber possessing existing fiber in the vicinity of the project site. Additional redundant fiber assets will be made available to the project site via connections planned with providers of telephone and video conferencing infrastructure (such as PG&E, AT&T and Comcast among others). This exclusive relationship between DWD and the fiber asset provider enables the MPRWP to not only support the onsite needs of the data center, but extend the reach of this infrastructure to Salinas via 1 Gigibit/Second hard wired fiber and to the agricultural growing region via 100MB/Second wireless infrastructure (which is more than adequate to support next generation soil sensing technology). High bandwidth users such as UC Santa Cruz, which currently houses massive amounts of data to support the Human Genome Project remotely in San Diego, suffer from the above mentioned latency problem and would greatly benefit by integrating into the proposed MBRWP infrastructure.
1.5.2.2.3 Potable Water and Sanitary Sewer During construction, potable water service could be provided to the project site by pipeline from the Moss Landing Mutual Water Company. Once the SWRO plant is operational, the MBRWP intends to be supplied water directly from the plant. Sanitary waste will be provided by the Castroville Community Services District and will require installation of new pipeline along the route shown in Figure 1.3.
1.5.2.3 Security The existing site is surrounded by a 7-foot high chain link fence. The perimeter of the proposed Project will be similarly fenced and will include three-strand barbed wire. Facilities within the Project perimeter, such as the electrical substation, may have additional fencing for both safety and security reasons. Access to the Project site will be through access-controlled automatic gates. The gates will include Knox Boxes or similar means by which emergency personnel can access the site.
1.5.2.4 Lighting Outdoor area lighting for the Project site will consist of permanently mounted fixtures secured to structures, equipment, walls and poles as required, providing access lighting for personnel and for security. The lighting system will be designed to provide nighttime lighting levels consistent with applicable standards.
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Fig 1.3 Routing for potable water and sanitary sewer service
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1.6 Alternative Locations Considered Two alternative locations for the Project were considered and eliminated. One site was the former National Refractories factory location located southwest of the intersection of State Hwy 1 and Dolan Road and now known as the Moss Landing Commercial Park. That site is no longer used as a refractory, though some of the industrial structures and infrastructure remain. The site offered an advantage of being closer to the location of the wet well, which would reduce the distance needed to pump seawater, and it is zoned for industrial use. The site was eliminated as an alternative for the following reasons:
None of the existing infrastructure remaining on the site was determined to be usable without significant demolition and reconstruction including existing buildings and concrete basins, which would have resulted in higher project cost than new purpose built construction on undeveloped land.
Concern about risks associated with the potential to encounter contamination resulting from past industrial uses of the site.
The other site considered for an alternative location is the Capurro Ranch. This site is located on the west side of State Hwy 1, approximately 1.1 miles north of the intersection of Hwy 1 and Dolan Road. The site provided access to the Monterey Bay Submarine Canyon and included some existing buildings with the potential to be repurposed for housing portions of the SWRO facility. The site was eliminated as an alternative for the following reasons:
Insufficient land was available to accommodate both the data center facilities and the SWRO facility.
The site did not have nearby access to the electrical and natural gas infrastructure needed to support the data center facilities. Access to those utilities would require crossing Elkhorn Slough with high-voltage electrical lines and natural gas pipelines.
Incompatible land use zoning.
1.7 Required Permits The following federal, state, and local agencies have regulatory authority over various aspects of the project or an ownership interest in the property to be utilized by the project. Federal Agencies
National Oceanic & Atmospheric Administration: Authorization by the Monterey Bay National Marine Sanctuary Superintendent of federal, state, and local agencies’ permits within the sanctuary in accordance with NOAA’s National Marine Sanctuary Program requirements for the MBNMS.
U.S. Army Corps of Engineers: Permit in accordance with Clean Water Act Section 404.
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U.S. Army Corps of Engineers: Permit in accordance with Rivers and Harbors Act Section 10.
U.S. Coast Guard: Approval for construction and use of structures located in and above navigable waterways.
Requirements for all Federal Agencies: o Consultation with the United States Fish and Wildlife Service and/or National
Marine Fisheries Service as required under Endangered Species Act of 1973, Migratory Bird Treaty Act, Fish and Wildlife Coordination Act, the Magnuson-Stevens Fishery Conservation and Management Act, the Marine Mammal Protection Act of 1972 and other federal laws.
o Consultation with the State Historic Preservation Officer and/or Tribal Historic Preservation Act of 1966.
o Consultation with the California Coastal Commission. o Consultation with the State Regional Water Quality Control Board. o Compliance with National Environmental Policy Act.
State Agencies
California Coastal Commission: Coastal Development Permit for all development below mean high tide line.
Regional Water Quality Control Board Central Coast Region: o Compliance with National Pollutant Discharge Elimination System General Permit
for Storm Water Discharges Associated With Construction Activity. o Compliance with National Pollutant Discharge Elimination System Permit in
accordance with Clean Water Act 402. o Compliance with Waste Discharge Requirements in accordance with Porter-
Cologne Water Quality Control Act. o Compliance with Water Quality Certification in accordance with Clean Water
Action Section 401.
State Water Resources Control Board: Order of approval for Regional Board Action.
California Department of Public Health: Permit to operate a Public Water System.
California Department of Transportation: Encroachment permits for structures to be located within State Highway right of way and consultation with State Historic Preservation Office regarding historic resources.
California Public Utilities Commission: Certificate of Public Convenience and Necessity (if a utility company regulated by the CPUC takes water from the Project).
California State Lands Commission: Permission to construct and use facilities to be located on land owned by State of California.
California State Parks temporary use permit: Permission to construct a temporary drill pit on sand spit adjacent to Moss Landing Harbor
For all State Agencies: Consultation and coordination with federal agencies, compliance with California Environmental Quality Act.
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Regional and Local Agencies
Monterey County: Coastal Development Permit for development to be located above the mean high water line within the Coastal Zone, unless the County defers its original Coastal Development Permit jurisdiction to the California Coastal Commission.
Monterey County Planning and Building Inspection Department: Erosion Control Permit for structures to be located within the county road right of way, Grading Permit, Erosion permit, Use Permit, and Coastal Development Permit in accordance with the California Coast Act.
County Health Department: Use Permit Permission to construct and operate a Desalination Facility.
Monterey Bay Unified Air Pollution Control District: Permission to construct and operate in accordance with Air Quality Regulations.
Moss Landing Harbor District: Permission to construct and use facilities located on or above submerged lands and uplands owned by MLHD.
Transportation Agency for Monterey County: Permission to construct and use facilities located on land owned by TAMC.
Monterey Peninsula Water Management District: Water System Expansion Permit (if a water purveyor within the MPWMD’s territory takes water from the DWD project).
For All Regional and Local Agencies: o Consultation and coordination with State and Federal Agencies and Permits. o Consultation with California Department of Fish and Wildlife o Compliance with California Environmental Quality Act.
1.8 Construction Plan Appendix D will include detailed construction scenarios regarding:
Intake/ Discharge Pipeline Construction*
Associated Intake and Discharge Infrastructure Construction*
*This information will be forthcoming from a report by Brierley Associates (February 2016)
Information related to construction scenarios for the SWRO, data center, site improvements and power facilities will be provided at a later date.
2. Seawater Reverse Osmosis Project Overview The MBRWP proposes to construct a seawater reverse osmosis desalination plant, together with its ancillary facilities, to produce up to 25,000 AFY of potable water. Ocean water withdrawal and potable water production rates, in both gallons per minute (GPM) and million gallons per day (MGD) are presented in Table 2.1.
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Table 2.1 MBRWP Design Flows for Seawater Withdrawal and Potable Water Production
Desalination Plant Rated Flow
Units
Seawater Withdrawal 33,800 GPM
48.7 MGD
Potable Water Production 15,500 GPM
22.3 MGD
The Project proposes to use a screened, low velocity, deep water, ocean intake located on the upper slope of the Monterey submarine canyon. The proposed intake structure will be mounted at the terminus of a newly constructed subsurface source water conveyance pipeline located approximately 1,000 feet offshore at a nominal depth of approximately 130 feet (final depth will be determined based on additional studies and design details).
2.1 Major SWRO Project Components The proposed SWRO will be comprised of the following major elements: A screened deep water ocean intake and conveyance system, including:
• Offshore, deep-water, low velocity, passive screened ocean intake structure • Subsurface seawater intake transfer pipeline • Onshore pump station • Subsurface seawater conveyance system from pump station to the project site
A seawater reverse osmosis desalination system, including:
• Pretreatment system • Spiral wound reverse osmosis seawater desalination system • Energy recovery system • Post treatment system • Solids handling system • System controls • Product water disinfection and stabilization system • Product water distribution high service pump system • Finished water conveyance system
A concentrate discharge system, including:
• Concentrate disposal conveyance piping - subsurface onshore and offshore • Concentrate pump station
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• High velocity duck-billed diffusers
2.2 Environmental Features The proposed MBRWP has been conceived and designed to minimize environmental impacts while producing high quality potable water at an affordable cost. Design features aimed at minimizing impacts include the following: (i) A passive, low velocity, screened deep-water sited ocean intake system; (ii) greenhouse gas emission reduction features; (iii) energy saving features; (iv) waste reduction features; (v) concentrate discharge outfall design that complies with all regulatory requirements for SWRO concentrate disposal in the open ocean. Table 2.2 summarizes the project design features and their environmental benefits.
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Table 2.2. Summary of Environmental Design, Construction, and Operational Features
Project Feature Design or Operational Feature Benefit
Passive, Screened, Low Velocity Deep Water Ocean Intake
Screened deep water ocean intake location below photic zone
Intake water velocity ≤0.5 feet/second
Wedgewire screen with 1 mm slot spacing
Reduces impacts associated with impingement and entrainment of marine organisms to insignificant levels
Deep water siting below the photic zone where the abundance of marine organisms is significantly less than in shallower water
Provides access to water with consistently higher quality, reducing pretreatment requirements
Ocean intake located at the head of the Monterey Submarine Canyon
Water from within the Canyon dominates the intake location and contains very few larval fish and shellfish.
Wedgewire screened deep water ocean intake
Provides access to deep water containing less larval fish and shellfish.
Larval fish in deeper water are generally larger and so an increase in the effectiveness of the wedgewire screening occurs that further limits entrainment and impingement.
Off-Shore Seawater Conveyance Piping
Constructed subsurface using hydraulic directional drilling (HDD)
Avoids impacts to marine areas along pipeline routes
Minimizes disruptions to recreational and commercial boating in Moss Landing Harbor
Offshore Discharge Structure with Brine Diffuser Ports
High-velocity duckbill diffusers extensively modeled to insure compliance with the 2015 Ocean Plan Amendments
Ensures rapid mixing of concentrate with receiving seawater, as has been extensively modeled.
Data Center Cooling Capturing waste heat from data center
buildings
Improves efficiency of desalination process with respect to energy consumption
Significantly reduces GHG emissions associated with data center cooling and the desalination processes
Energy Recovery System Recovers energy from the high pressure
RO concentrate stream for recycle to boost the incoming feed water pressure.
Reduces the overall pumping energy required for desalination, thereby saving electrical energy.
Reduces GHG emissions associated with the desalination process.
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Project Feature Design or Operational Feature Benefit
Other Energy Minimization and GHG Reduction Measures being considered
A GHG Reduction and Minimization Study will be conducted in 2017 to evaluate how to reduce the carbon footprint of the Project and make it net-carbon neutral. Potential projects include:
o Carbon capture from on-site back-up power generators
o Indirect free cooling, economization system for data center
o Purchase 100% green power from the power provider
o Purchase RECs or GHG credits
o Geothermal ground loops to reduce SWRO brine temperatures
o Solar Panels
Helps California meet its GHG goals for 2020 and 2050
Helps make the MBRWP net-carbon neutral
Additional Applicant Proposed Measures: In addition to those listed above, the following are also proposed measures that will be included in the MBRWP work tasks during permitting, design, and construction.
1. Sensitive habitat, including native grasslands, riparian, and wetlands, shall be avoided to the greatest extent feasible*.
2. A wetlands assessment and habitat assessment shall be conducted for the distribution pipeline prior to permitting*.
3. Focused surveys shall be conducted within the project areas to determine their presence or absence, if needed*.
4. Construction activities should be conducted during dry weather conditions to avoid erosion issues and impacts to migrating special status amphibians, if present*.
5. An employee education program be conducted prior to the construction activities to inform the construction crew of the sensitive resources present and the protections afforded to them.
6. Create avoidance and minimization measures for sensitive habitat and special-status plants*. 7. Develop a Habitat Mitigation and Monitoring Plan* 8. Establish general noise controls for construction equipment 9. Develop site-specific construction lighting measures. 10. Develop a traffic control and safety assurance plan 11. Develop a dust control plan and a stormwater management plan 12. Develop a construction equipment efficiency plan 13. Develop a GHG Reduction and Implementation Plan 14. Establish construction worker parking requirements 15. Develop a drilling and fluids management plan for the marine environment to be used during
construction. * Will be further discussed in the forthcoming reports by EMC Planning (Spring 2016)
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2.3 Intake and Discharge System Overview A primary and secondary alternative have been developed to convey seawater and brine concentrate between the offshore intake and discharge structures. Overall the alternatives are generally similar since they have similar pipeline alignments, include a pump station to take water from a screened intake structure located within the Monterey Bay submarine canyon, and transmit brine to a diffuser located on north edge of the Monterey Bay submarine canyon. The discharge and intake locations are nearly identical for each alternative. Figure 2.1 and 2.2 present the proposed and secondary alternatives for intake and discharge pipeline alignments and pump station locations in plan view.
Figure 2.1 Proposed Intake and Discharge Pipeline Alignments and Pump Station
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Figure 2.2 Secondary Intake and Discharge Pipeline Alignments and Pump Station
A general description of features for the proposed alternative (Fig. 2.1) is listed below:
A pump station (IPS-1) will be installed along the northern portion of Dolan Road at the end of an existing railroad spur.
A screened intake structure (IS-1) will be secured to the seafloor within a ravine of the Monterey Bay submarine canyon. Seawater will be conveyed between IS-1 and the pump station within 2 x 42-in dia. pipelines that are installed via Horizontal Directional Drilling method or a similar technique.
A seafloor diffuser structure (BCD-1) will be secured to the seafloor west above the Monterey Canyon submarine canyon. Brine will be conveyed between BCD-1 and the pump station within 2 x 36-in dia. pipelines that are installed via Horizontal Directional Drilling method or a similar technique.
Between the pump station and desalination plant, seawater and brine will be conveyed within 4 x 36-in dia. pipelines below the westbound lane of Dolan Road. These pipelines will be placed using conventional trenching techniques.
A general description of features for the secondary alternative (Fig. 2.2) is listed below:
A pump station (IPS-2) will be installed west of Sandholdt Road within an existing easement for the existing Moss Landing Power Plant discharge tunnels.
A screened intake structure (IS-1) will be secured to the seafloor within a ravine of the Monterey Bay submarine canyon. Seawater will be conveyed between IS-1 and the
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pump station within 2 x 42-in dia. pipelines that are installed via Horizontal Directional Drilling method or a similar technique.
A seafloor diffuser structure (BCD-1) will be secured to the seafloor west above the Monterey Canyon submarine canyon. Brine will be conveyed between BCD-1 and the pump station within 2 x 36-in dia. pipelines that are installed via Horizontal Directional Drilling method or a similar technique.
Between the pump station and desalination plant, seawater and brine will be conveyed within 4 x 36-in dia. pipelines that cross the Moss Landing Harbor channel within one of the existing MLLP 12’ tunnels. Once across the channel, the pipelines will be conveyed below State Highway 1and onto Dolan Road within a tunnel created using micro-tunneling. Using conventional trenching techniques, the pipelines will then run in the westbound lane of Dolan Road to the plant.
A third alternative was also identified for the MBRWP using a northern routing from the East Tank Farm parcel as shown in Figure 2.3.
Figure 2.3 Northern Alternative Intake and Discharge Pipeline Alignments and Pump Station,
Brierley (2014) A general description of features for the alternative from Brierley (2014) and presented in Fig. 2.3 is listed below and was described in the June 2015 NOP/NOI:
A pump station (IPS-3) will be installed west of SR-1 and east of the Moss Landing Harbor Channel on Moss Landing Power Plant property.
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A screened intake structure (IS-2) will be secured to the canyon wall on the north side of the Monterey Bay submarine canyon. Seawater will be conveyed between IS-2 and a construction shaft within an existing parking lot in 2 x 42-in dia. pipelines. The pipeline are planned to be installed using the Horizontal Directional Drilling method or a similar technique.
A seafloor diffuser structure (BCD-2) will be secured to the seafloor on the shelf above the Monterey Canyon submarine canyon. Brine will be conveyed between BCD-2 and a construction shaft within an existing parking lot at Moss Landing State Beach in 2 x 36-in dia. pipelines. The pipelines are planned to be installed using the Horizontal Directional Drilling method or a similar technique.
Between the construction shaft and pump station, seawater and brine will be conveyed within 4 x 36-in dia. pipelines that cross the Moss Landing Harbor channel within a newly installed 10-ft dia. microtunnel.
From the pump station, the 4 x 36-in dia. pipelines will be conveyed below SR-1 and onto Moss Landing Power Plant property within separate steel casings. Jack and bore techniques will be used to install the casings.
Using conventional trenching techniques, the 4 x 36-in dia. pipelines will then run around the north side of the Moss Landing Power Plant to the desalination facility.
Additional details on the design and preliminary construction of various elements of the proposed and secondary alternative are provided in subsequent sections of this report. Details for the alternative presented in Brierley (2014) are not included (See Appendix D). A forthcoming ‘Intake and Outfall Construction Analysis Report will be completed in February 2016 and provided to the lead agencies.
2.3.1 Intake A central consideration in selecting Moss Landing as the location of the MBRWP is the proximity to the Monterey Bay submarine canyon. Withdrawing source water from deep below the ocean surface will minimize environmental impacts that are a concern for open ocean intakes located in shallow water. Independent scientific assessments conducted on behalf of the MBRWP have confirmed that, due to a reduction in larval abundance in deeper water and the presence of a deep water mass that predominates at the head of the Monterey Submarine Canyon, fewer planktonic marine organisms are present in the water column at the depth of the proposed intake. The near-shore access to deep water and the nature of the movement of water masses at the head of Monterey Submarine Canyon makes siting an intake in deep water at Moss Landing economically and technically feasible where it otherwise would not be for other coastal locations. The proposed intake structure (IS-1) is located near the head of the submarine canyon approximately one-quarter mile southwest of the Moss Landing Harbor entrance, at a depth of approximately 130 feet. The location of the proposed intake structure is shown in Figure 2.4.
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Horizontal location relative to latitude and longitude and planned elevation of IS-1 and other proposed or existing seafloor structures is provided in Table 2.3.
Figure 2.4. Intake and Discharge Site Locations
Table 2.3. Locations of Intake and Discharge Structures
ID No. Description Elevation1 (ft) Latitude (deg) Longitude (deg)
BCD-1 Preferred Discharge Structure Location -65 36.8126 -121.8091
BCD-2 Alternative Discharge Structure Location -65 36.8084 -121.7986
IS-1 Preferred Intake Structure Location -130 36.8033 -121.7924
IS-2 Alternative Intake Structure Location -130 36.8069 -121.7982
MLPP Existing Moss Landing Power Plant Outfall -25 36.8043 -121.7910 1Approximate elevation relative to Mean Lower Low Water (MLLW)
An alternative location for the intake structure (IS-2) was identified half-mile offshore and northwest of the harbor entrance. This location was originally identified in the July 1 NOP/NOI; however, due to potential cultural and habitat resources issues with this alignment, it was not further pursued. Selection of the intake location was based on the following considerations:
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1. A deep-water depth of approximately 130-ft in order to locate the intake within the zone periodically occupied by the deep water mass and reduced larval abundances, to achieve reduced impact on marine organisms resulting from entrainment.
2. A deep water body mass site with access to consistent quality seawater, that is expected to be low in turbidity and not subject to periodic high turbidity (suspended sediment or organic matter) events resulting from storm water runoff, wave action and red tide events.
A site with sufficient ocean cross currents to “sweep” the wedgewire screens of the intake structure, thereby minimizing impingement and entrainment and maintaining the cleanliness of the screens.
2.3.2 Intake Structure Seawater is proposed to be extracted through a passive, screened, low velocity engineered intake structure located offshore at a depth of approximately 130 feet below mean lower low water. Between the intake structure and onshore pump station, two pipelines will convey seawater. The pipelines will be installed below the seafloor using Horizontal Directional Drilling (HDD) or a similar technique. A preliminary design of the intake structure is shown Figure 2.5
Figure 2.5. Conceptual Intake Structure
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The overall dimensions of the intake structure is about 85-ft long, 30-ft wide, and 12-ft in height. At the breakout face where the dual pipelines emerge from the seafloor, the screening manifold for each pipe will be connected with flexible couplings to allow for some movement. Piping that supports the screens will be secured to reinforced concrete pads with pipe supports and straps. The pads will be secured to the ocean floor with embedment and deadweight type anchors. Screen sections may be removed entirely for maintenance purposes with little downtime; and the end of each pipe may be removed to facilitate cleaning or pigging. An example of a passive screen system is provided in Figure 2.6.
Figure 2.6. Passive engineered intake screen assembly
In addition to the passive 1mm slot size opening wedgewire screens, the screened deep water intake water velocity will be at or below the regulatory standards for open ocean intakes (0.5 feet-per-second). The combined approach of locating the intake in a deeper canyon depth, intake slot size screening and minimized intake velocity will meet the regulatory standard of Best Technology Available for reducing the environmental effects of planned seawater intake. Construction of the intake structure will occur after installation of the pipelines has been completed. The bed of intake structure may need to be prepared below the concrete pads. This will be accomplished using diver assisted or lead dredging using suction and/or mechanical techniques. The amount of seafloor materials to be removed is dependent on the local changes in
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bathymetric grade, but should be confined within the planned area 120-ft by 50-ft to accommodate the intake structure. Excavated materials will be transferred to a barge and disposed of in a suitable area onshore or offshore. Embedment type anchors are currently anticipated to be set in the seafloor to secure the concrete pads since the intake will be placed within a ravine that has a slope of about 10 horizontal to 1 vertical. These will be set prior to the setting of pads on the seafloor with locations determined using a template. The anchors could extend tens of feet below the seafloor, with the number and depth being dependent on geologic and geotechnical conditions. If the sub-seafloor materials are soft, then screw type anchors will be installed; but if the sub-seafloor materials are hard, then grouted screw or micropiles will likely be installed. Alternatively, gravity type anchors could be used to secure the intake structure in place, but ballast would likely be required to hold the structure on the seafloor. Once the anchorages have been placed, the intake structure will be placed on the seafloor. The entire assembly would likely be built offsite and transported to the project site, then lowered to the seafloor by crane and set into place by divers. Alternatively, the intake structure could be assembled in place by divers as needed using modular components that are fabricated offsite then barged to the site. Once the intake structure has been installed, prefabricated section of stiff or flexible pipe would be used to connect intake structure to the subseafloor pipelines.
2.3.3 Alternatives to Screened Deepwater Ocean Intake As outlined in the 2015 Ocean Plan, the regional water board shall require subsurface intakes unless it determines that subsurface intakes are not feasible based on a comparative analysis of factors. These factors include geotechnical data, presence of sensitive habitat, energy use for the entire facility, design constraints (engineering, constructability), and project life cycle cost. Subsurface intakes include vertical beach wells, horizontal (radial) intake wells, slant wells and near-shore infiltration galleries. These intakes can offer some advantages over screened deep water ocean intakes. These include elimination of certain impacts to marine organisms, discussed in further detail below. For highly contaminated intake locations, e.g. in an active harbor, subsurface intakes also reduce the need for pretreatment upstream of the reverse osmosis membranes to remove a comparatively greater amount of suspended material from the source water body compared to other traditional intake systems; resulting in improved pretreated water quality. However, subsurface intakes are relatively new, not widely in use for large capacity SWRO plants, and their sustainable performance is highly site dependent.
2.3.3.1 Regulatory Considerations One concern about the intake of ocean water for industrial uses is the potential impacts to marine organisms. The intake of seawater for industrial purposes effects planktonic organisms
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and larvae that live within the water body. These plankton and larvae may be impinged or entrained resulting in mortality. To reduce this mortality, the intake for the desalination facility must comply with State Water Code Section 13142.5(b), which states, “For each new or expanded coastal power plant or other industrial installation using seawater for cooling, heating, or industrial processing, the best available site, design, technology, and mitigation measures feasible shall be used to minimize the intake and mortality of all forms of marine life.” The use of a subsurface intake whereby seawater is pre filtered through a sand bottom filter can eliminate impingement and entrainment. However, subsurface intakes are not always feasible particularly for projects for this size and capacity, and may result in considerable environmental impacts, such as impacts in the coastal zone related to the construction and operation of well fields, restricted beach access to the public and potentially significant greenhouse gas emissions.
2.3.3.2 Evaluation of Subsurface Intake Alternative Evaluation by EcoSystems Management Associates, Inc. (EMA) The MBRWP commissioned an independent assessment to study whether subsurface wells could provide an alternative source of seawater for the project. Ecosystems Management Associates, Inc. (EMA) assessed the hydrogeological feasibility of extracting the volume of seawater necessary to produce a 25,000 AFY of desalinated water using subsurface intakes. The firm conducted a comprehensive literature review of relevant data in the Moss Landing region as well as a survey of subsurface beach well intake systems for seawater desalinating plants presently in operation. Subsurface intakes are a relatively new method for seawater extraction for desalination and are not widely in use due to their high cost of construction and maintenance and technical risk of diminishing flow over time. The vast majority of SWRO projects worldwide use open ocean intakes to supply their source water. While subsurface intake systems for SWRO desalination plants may improve feed water quality in some cases, the feasibility of subsurface intake systems for desalination plants depends on the local hydrogeological conditions, site location and available space, engineering concerns, hazards, and the proposed capacity of SWRO plant. In other words, the feasibility of subsurface wells is highly project and site dependent. The study conducted by EMA included a hydrogeological analysis to assess whether the subsurface geology would likely provide sufficient recharge rates from the ocean to result in sustainable, high capacity subsurface wells. The EMA study makes the following conclusions regarding the feasibility of subsurface intakes to supply the MBRWP:
1. Major coarse-grained aquifers exist at about 180 ft. and 400 ft. below sea level along the coast. In addition, a shallow aquifer in alluvium, eolian, and older dune sand exists along the coast, but may have poor water quality (California American Water [Cal Am], 2013).
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2. Seawater intrusion has occurred in these aquifers since at least the 1930s. In the Moss Landing area, saline water has reached farther (1.75-2.5 miles) inland in the upper (180-foot or upper Aromas Sand) aquifer, and not as far inland (0.75-1.2 miles) in the lower (400-foot or lower Aromas Sand) aquifer.
3. Layers of fine-grained deposits between and within the major aquifers form aquitards that limit the vertical flow and recharge of the major aquifers. The depth of saline water observed in coastal wells is vertically restricted and not continuous throughout the main aquifer deposits.
4. Models of seawater intrusion assume that the source waters enter the aquifers in the walls of the Monterey Canyon offshore, which reduces the recharge rates that may be achieved if vertical flow were unrestricted by the shallow aquitards.
5. Considering the limited recharge rates of seawater intrusion, it is likely that subsurface intake systems would require a large number of wells or intake pipe arrays to provide the amount of seawater needed for a large-scale desalination plant. Test wells along the beach may provide data to quantify what flow rates may be achieved at various aquifer levels. Preliminary test well data south of Elkhorn Slough failed to achieve significant seawater flow rates.
6. Design of a subsurface intake system should be thought out carefully so that the optimal location of the intake is selected in order to achieve the necessary recharge of seawater, avoid geologic hazards from earthquakes and liquefaction, and minimize impacts on Monterey Canyon.
7. Subsurface intake systems are newly evolving technologies, and at present are likely suitable for small desalination plants (about 10 mgd). Their success will depend on the recharge rate, water quality, engineering concerns, geological hazards, maintenance, and other factors.
The results of the study suggest that more than 30 beach wells would be required in order to supply the volume of source water required. Assuming the typical well spacing distance of approximately 1,000 feet, the 30 wells would be distributed over nearly 6 miles of coastline. The costs and environmental impacts associated with installing, interconnecting, and operating such a large well field make subsurface wells an infeasible alternative. The complete EMA report is included in Appendix B. Evaluation by William Bourcier The MBRWP commissioned an independent assessment to study the potential greenhouse gas release from subsurface desalination feeds by William Bourcier. Marine sediment pore waters commonly contain elevated concentrations of GHG and methane which are generated by microbial degradation of organic matter present in the sediment, often 10 to 100 times higher than at atmospheric values. Essentially all these gases will be released from the subsurface ocean water once the fluid is brought to the surface and allowed to equilibrate with the atmosphere. Thus, subsurface intake source water has the potential to emit substantial GHG emissions based just on its water composition. To measure and analyze the gas contents in subsurface ocean water, Bourcier collected compositional data for fluids sampled from the exploratory bore holes contained in the Cal-Am EIR. Based on this data, the Moss Landing
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samples have an average partial pressure of carbon dioxide that are 120 times higher than atmospheric values. Thus, the use of subsurface source water with high levels elevated concentrations of GHGs would increase the MBRWP’s carbon footprint as compared to deep canyon ocean water. The letter report by Bourcier is included in Appendix B. Evaluation by GeoScience for Cal-Am and Peer Review by HydroMetrics WRI Hydrogeology and geotechnical data was recently collected with exploratory borings evaluated in the Moss Landing area. Based on this data and analysis by GeoScience in 2013-2014, it was concluded that subsurface wells for desalination were not feasible in Moss Landing due to physical constraints (thickness of permeable unit) to produce adequate feed water supply for desalination. (http://www.cpuc.ca.gov/Environment/info/esa/mpwsp/deir/AppendixC3.pdf). Peer review of this work by GeoScience was conducted by HydroMetrics WRI who concurred with the analysis that Moss Landing area was not a feasible location for subsurface intake. Evaluation by GeoScience did speculate that subsurface intakes could potentially be feasible near Protero Road; however, data was limited to one bore hole within that vicinity. GeoScience stated that pumping at this location has an impact on inland aquifers. DWD is currently planning further evaluation of the feasibility of a subsurface intake system near Protero Road and will submit additional information at a later date. Subsurface intakes for seawater desalination are relatively new, not widely in use for large capacity SWRO plants, and thus limited data on performance has not proven that this method can reliably and sustainably provide an adequate water supply. DWD will also continue to monitor the subsurface evaluation of test slant wells in Marina by HydroFocus and the peer review by Lawrence Berkeley National Laboratory.
2.3.4 Marine Biological Impacts
The MBRWP undertook an assessment of the potential effects of entrainment of marine larvae (fishes and invertebrates) due to the withdrawal of seawater through an ocean intake. Entrainment occurs when small, generally planktonic marine organisms pass through the intake screening system into the industrial facility, resulting in the death of those organisms. Tenera Environmental (Tenera) was hired to undertake a year-long field sampling program and to provide an analysis of the potential effects of the intake in accordance with the current best practice in the state of California. The study design and assessment approach used by Tenera was similar to that used for much larger intakes associated with coastal electric generating facilities, and also for other proposed coastal desalination facilities located elsewhere in California. The method of assessment applied in this study is called the Empirical Transport Model (ETM). The goal of the ETM is to produce an estimate of proportional mortality (PM), which is the proportion of larvae lost from
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a source water population due to entrainment. To derive the source water population, an empirically based hydrodynamic model of larval transportation was developed that incorporated the surface circulation and internal tide dynamics of Monterey Bay and the submarine canyon system. This model was combined with life history information and age estimates of the larvae collected in the field sampling to estimate the source water population size for each taxa. The calculated annual entrainment of each taxa was based on the sampled concentrations of larvae and was expressed as a proportion of the source water population at risk of entrainment.
The outcomes of the ETM indicated that for each of the taxa examined, no more than 0.1% of the source water population would be entrained. Relative to natural rates of mortality of larval fish and fishing quotas assigned for commercial fisheries, this proportion is so low that it is highly unlikely to have any effect at the population level. The study demonstrated that constructing the intake pipe to entrain seawater from 100 to 130 feet below mean sea level will result in a reduction in total larval entrainment relative to the shallower depths typical of seawater intake pipes in California as there are fewer larvae at these deeper depths. The study also investigated the implications of the internal tide that transports (advects) deep, cold canyon water onto the shelf at the head of the Monterey Canyon, the proposed location of the intake. This water was shown to have fewer larvae and fewer species of larvae than the warmer surface strata. By locating the intake at the head of the Canyon, this deep water that wells up from within the Canyon upwelling will be entrained as intake water twice daily throughout the year, further reducing the rate of entrainment. The entrainment assessment is provided in Appendix C.
2.4 Seawater Conveyance from Desalination Plant to Onshore Pump Station and Off-shore Intake Structure
Seawater will be conveyed from the intake to an on-shore pump station via two 42-inch diameter pipes. Dual intake pipes were selected rather than a single large diameter pipe to provide for system redundancy and maintain flows during pipeline maintenance. The MBRWP retained Brierley Associates to conduct a feasibility study associated with the construction of the seawater conveyance system. The firm was asked to evaluate the methods of construction, routing and constructability of the intake and discharge conveyance pipelines. Brierley Associates evaluated a number of potential construction technologies and methods to deploy and secure the pipelines.
2.4.1 Offshore Conveyance Construction The proposed conceptual intake system (IS-1) calls for 2 x 42-inch diameter seawater intake pipelines connected to the passive wedgewire screen system to allow for one screen/pipeline to be out of service for maintenance while the other screen/pipeline system is in service. The conceptual intake structure is shown in Fig. 2.5.
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To minimize environmental impacts associated with the construction and operation of the pipelines and to avoid hazards to navigation in the near shore segments, Brierley recommended the 42-inch dual pipelines be constructed subsurface using horizontal directional drilling (HDD) from the pump station near the end of the railspur (corner of Dolan Road and Hwy 1) to the off-shore seawater intake structure location. Figure 2.7 depicts the planned HDD installation for the intake pipelines. The HDD segment can be installed prior to or during the construction of pump station (IPS-1) from an entry pit (Shaft/Pit 01) located within 200-ft east of the pump station within the footprint of the railroad spur. Prior to installation of these pipelines, the railroad spur and underlying embankment will be removed, and the site graded to the final elevation of the pump station. Figure 2.7 depicts the general configuration the entry pit and pipelines relative to the pump station (IPS-1).
Figure 2.7. HDD Intake and Discharge Pipeline Relative to Entry Pit for Proposed Option
As shown in Fig. 2.7, The HDD segment of the intake pipelines will traverse down the north side of Dolan Road, go across SR-1, across the Moss Landing Harbor Channel and Moss Landing Sand Spit within the discharge tunnel easement of the Moss Landing Power Plant, and then offshore to intake structure. The depth of the pipelines will be over 100-ft below SR-1, the channel, and sand spit. The shallowest portions of the pipelines will be near the pump station and intake structure. Both intake pipelines will have similar elevations will be separated by 10- to 20-ft along the alignment.
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The HDD method uses a surface launched drill rig to drill a pilot bore to the target site (discharge and intake locations). The pilot bore is enlarged by a back reamer(s) to pre-ream to the size required for the product pipe. The pipe is pulled back through during the final reaming process. Figure 2.8 illustrates the HDD pipeline installation method.
Figure 2.8. Depiction of HDD Pipeline Installation
Between the pump station and desalination plant, the intake lines will run below Dolan Road. These lines will be installed within a conventional trench that is approximately 10-ft wide and
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15-ft deep. Approximately 5- to 10-ft of cover will be provided between the top of the pipeline and roadway. Alternatives for the off-shore seawater conveyance alignment included:
Secondary alternative: Dual 42-inch diameter seawater intake pipeline would be constructed using HDD to the uppermost northern slope of the Monterey Submarine Canyon, northwest of the Moss Landing Harbor entrance to IS-2 (see Figure 2.3). This alternative was included in the NOP/NOI issued on June 1, 2015 for the Monterey Bay Regional Water Project but is no longer being considered due to the cultural/biological constraints with the on-shore routing of this alignment.
Tertiary Alternative: Dual 42-inch diameter seawater intake pipelines would be installed within an existing 12 foot diameter unused Moss Landing Power Plant discharge tunnel owned and operated by Dynegy as a means get under the Harbor with a pump station located on the sandspit on Sandholdt Road. The intake pipeline would then be constructed subsurface using HDD from the pump station on Sandholdt Road to the off-shore seawater intake structure location IS-1.
Installation of intake pipelines via HDD are similar as described above for the secondary alternative. The third option includes installation of pipelines in an existing MLPP 12-ft dia. discharge tunnel and construction of a tunnel below SR-1. Limited demolition of the existing MLPP tunnel would be required near Sandholdt Road and SR-1 to place pipe inside the tunnel. It will also require a 10-ft dia. tunnel be constructed to place pipe below SR-1. Pipelines down Dolan Road to the desalination facility will use conventional trenching techniques as described for the proposed alternative.
2.5 Onshore Pump Station and Data Center Booster Pump Station The proposed pump station (IPS-1) will be constructed to hydraulically move the seawater to the desalination facility located off Dolan Road. The proposed pump station will located at the end of the railroad spur near Dynegy’s Moss Landing Power Plant and Hwy 1. The pump station will contain four centrifugal intake pumps (three operating and one stand-by) each with a rated capacity of approximately 12,000 GPM and with a discharge pressure of 150 PSIG. Additional features of the intake pump station include a pig launching system, cathodic protection, and water quality sampling station. The centrifugal pumps will be located below grade in a 108’x30’ pump station. The only equipment planned to be above-grade are transformers and an emergency backup power supply system that would be housed in a small building. A conceptual design of the pump station is provided in Figures 2.9, 2.10 and 2.11. An alternative 30’x62’ pump station (IPS-2) located on Sandholdt Road was also evaluated which included a wet well and vertical pumps to move the seawater to the desalination facility on Dolan Road. This alternative included four vertical turbine intake pumps (three operating and one stand-by) each with a rated capacity of approximately 12,000 GPM and with a discharge pressure of 150 PSIG. Additional features of this alternative intake pump station
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include a pig launching system, cathodic protection, and water quality sampling station. The vertical pumps will be located below grade with a one-story small building to include the wet well and pumps as well as the transformers and an emergency backup power supply. A conceptual design of the pump station is provided in Appendix D. Another alternative pump station (IPS-3) location was also identified in the NOP/NOI and located west of State HWY 1, across from the MLPP. From there, the pipeline corridor was to cross under Highway 1, and would proceed north before continuing to run in an easterly direction, dropping south into the Project site. The alignment is previously shown in Figure 2.3. This alternative was included in the NOP/NOI issued on June 1, 2015 for but is no longer being considered due to potential cultural/biological constraints with the on-shore routing of this alignment.
Figure 2.9
Figure 2.10
Figure 2.11
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A chemical biofouling control system is included in the design of the pump station, although the need for biofouling control cannot be determined until after the system is operational. The purpose of the biofouling control is to prevent biological growth on the walls of the conveyance pipelines, which can affect water flow and increase energy demand. If required, biofouling control would be accomplished by periodic dosing with liquid sodium hypochlorite. However, based on our prior experience with cold-water intakes, it is likely that biofouling will not be a significant issue due to the extremely cold temperature of the source water, which will limit biological growth. The intake conveyance piping system will include multiple manifold access points at the project site from which slipstreams of cold seawater can be directed to individual data center buildings for use in non-contact cooling. From the data center building, the warmed seawater will be pumped back to the intake pipeline. Following the data center interconnections, the warmed seawater will flow into an interim warm water holding tank, with a nominal capacity of approximately 350,000 gallons. From the holding tank, the warmed seawater will be pumped to the desalination facility by a booster pump station located within the data center boundary. The booster pump station is designed at the same capacity and redundancy as the intake pump station.
2.6 Heat Transfer Process An initial step to the SWRO treatment process includes capturing the heat from the data center. A closed loop cooling system is proposed to provide air conditioning to both office and computer server areas of the data center buildings. In lieu of the chiller units and evaporative cooling systems typically employed for building air conditioning, the data centers will reject heat to the cold seawater being pumped to the inlet side of the SWRO facility. Cold seawater will run through a non-contact, tube-and-shell or plate style heat exchanger where it will collect heat from the data center cooling system. The heat exchanger will be made of either titanium or an admiralty metal to avoid problems with corrosion. After leaving the heat exchanger, the warmed seawater will be recombined with the SWRO inlet pipeline. The proposed seawater cooling loops will be individually monitored for both flow and temperature prior to recombination with the SWRO inlet pipeline. Conceptual design information is forthcoming in March 2016.
2.7 Reverse Osmosis Desalination System Reverse osmosis desalination is a cross-flow separation process using polymeric semi-permeable membranes to separate and concentrate dissolved minerals (salts) from seawater. In RO desalination, when the feed stream is pretreated and pressurized against the membrane surface, two resulting streams emerge: high quality permeate (the water that will eventually
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become potable water) and a concentrated feed water solution (also termed concentrate or brine). The membrane has the ability to reject nearly all of the dissolved minerals (99.85% or greater), concentrating them on the feed side of the membrane. As permeate is produced, the volume of the feed is reduced and the concentration of salts increases until the concentrated brine is discharged from the outlet side of the RO membrane trains. For seawater, the ratio of the volume of permeate to the volume of the feed water typically ranges from 40 to 50%. In other words, for every 100 gallons of feed introduced into the RO system, approximately 40 to 50 gallons of permeate and 50 to 60 gallons of concentrate are produced. Process flow diagrams and conceptual general arrangement for the SWRO system will be forthcoming.
2.7.1 SWRO Pretreatment System Prior to desalination, the seawater requires filtration to remove suspended solids and organic matter that could foul the SWRO membranes and potentially cause more frequent membrane cleanings and a shortened membrane service life. The pretreatment system will primarily consist of single-stage, deep-bed, dual media filtration system with sufficient redundancy to ensure reliable, sustainable, source water supply to the downstream desalination process. Additional pre-treatment may be required in the event of periodic turbidity spikes that may occur from red tide events, storm water discharges caused by flooding of the Salinas River, or other temporary, short-duration events. We do not anticipate that any of these events will adversely affect the source water quality at the deep-water intake location. However, prudent engineering requires that the process design consider the capability of the pretreatment system to accommodate such additional steps; such as coagulation – flocculation – sedimentation or dissolved air flotation ("DAF"). A more robust pretreatment process such as this may also be needed to reduce chemical cleaning frequency and maximize the operational life of the membrane elements. Ferric (iron) -based coagulant, filter aid polymer, and sodium hypochlorite storage and dosing systems are integrated into the design to improve the filtration efficiency of the pretreatment system during system operation. As is the case with other chemical treatment processes, the need for chemical treatment upstream of filtration will be determined during routine operations. Such chemical treatment may be needed intermittently during periods when the source water temporarily contains higher concentrations of organic matter or other suspended solids. The media filters are designed to utilize filtered seawater as a source of backwash water or alternatively, RO concentrate. Virtually all of the backwash wastewater will be recycled through a backwash reclaim system, which is discussed in Section 2.7.2.1.
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Following pretreatment, filtered water will pass through micron cartridge filters that will serve as guard filters to capture any residual material that may not be removed in the media filters. Redundancy is built-in so that one cartridge filter may be offline for cartridge replacement without affecting the production of the facility. The cartridge filter vessels will be rubber-lined carbon steel or high alloy duplex stainless steel. Based on the design recovery and feed water quality conditions, anti-scalant is not anticipated to be required. However, as with other chemical treatment systems, the SWRO design includes provisions for scale control and a determination as to whether it’s required will be made based upon operational experience.
2.7.2 Reverse Osmosis Desalination
Seawater feed pumps will be dedicated to each respective membrane treatment train. Although the size and quantity of trains may change, overall system capacity will not. Presently, ten SWRO pumps (plus one stand-by) will be used to pump the seawater through the reverse osmosis membranes. Each pump has a rated capacity of approximately 1,600 gpm and will be capable of discharge pressures ranging from 850 to 1,000 psi. An integrated isobaric energy recovery system, described later in more detail, recaptures hydraulic energy from the brine stream. The SWRO and energy recovery systems will be designed using a modular array and skid approach. One complete standby SWRO skid and energy recovery system will be available to ensure reliable water plant production.
The entire membrane and energy recovery systems will be automated and operating conditions such as pressure and water quality will be continuously monitored using sensors and fully integrated computer control systems. Materials of construction for the system include duplex and super-duplex stainless steels for high-pressure, high salinity pipes and valves; and GRP (glass reinforced fiberglass) or thermoplastic for low-pressure pipes and valves. Under the provisions of the federal Safe Drinking Water Act (SDWA) and the State of California (CA) via the CA State Water Resources Control Board (SWRCB), Division of Drinking Water (DDW) has elected to adopt, modify, implement, and enforce public drinking water standards via regulation and policy under California state law. Therefore, DDW has primary responsibility (referred to as “primacy”) over the federal law and regulations. DDW establishes CA maximum contaminant levels (MCLs) based on public health goals established by the CA Office of Environmental Health Hazard Assessment (OEHHA). Accordingly, the facility is designed to be compliant with the following rules and regulations:
• Surface Water Treatment Rule (SWTR) • Disinfectants/Disinfection Byproducts Rule (D/DBPR) • Filter Backwash Recycling Rule (FBRR) • Lead and Copper Rule (LCR) • Total Coliform Rule (TCR)
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• Primary WQ Standards • Secondary WQ Standards • CA Notification Levels
2.7.2.1 Filter Backwash and Membrane Cleaning The granular media filtration system described in Section 2.7.1 will require periodic backwashing to remove accumulated solids retained by the filters. Filter backwash will be collected and treated in a backwash solids handling system consisting of a lamella clarifier/ solids settling system with integrated surge basin, and either a belt filter press or centrifuges to achieve greater than 20-percent dry solids. The basin will be glass lined bolted steel or concrete, designed to contain sufficient backwash volume to stabilize feed flow to the solids settling system. A mixture of duplex stainless steel and thermoplastic valves, pipe and fittings will be used throughout the system. The SWRO membranes will require periodic cleaning to remove foulants in order to maintain efficiency. The cleaning process typically includes the use of a detergent in either an acid or base solution, depending on the nature of material being removed. Spent (used) membrane cleaning solution will be collected and neutralized prior to discharge into the brine discharge line or alternatively to the sanitary sewer as determined by applicable regulation. The neutralization tank will have a capacity equal to one complete membrane cleaning event (approximately 7,000 gallons) and will be constructed of glass lined bolted steel, fiberglass, or concrete. Approximately four membrane cleaning events are anticipated annually.
2.7.3 Energy Recovery The system will be supplied with an integrated isobaric energy recovery system to capture hydraulic energy from the high pressure SWRO brine stream and transfer that energy to approximately 52 to 54-percent of the filtered water from the pretreatment system. The remaining fraction is pressurized through high pressure SWRO feed pumps. The two streams are blended together feeding the SWRO membrane treatment train.
2.7.4 Permeate Post-Treatment: Disinfection and Stabilization A portion of the SWRO permeate requires post-treatment conditioning with calcite and carbon dioxide for pH adjustment and stabilization; followed by disinfection. Sulfuric acid may be utilized to assist with calcite dissolution; and sodium hydroxide may also be used for pH control downstream of the calcite contactors. The post-treatment system forwards desalted permeate to a draw-back tank where a portion is re-pressurized and sent to the calcite contactors; and the remaining portion is forwarded to the finished water storage tank. Eight operating (and one stand-by) forwarding pumps, each with a
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rated capacity of approximately 1,940 gpm at a discharge pressure of 35 psig, will be used to feed the calcite system. Redundancy is built in to the post treatment system with one complete standby calcite and carbon dioxide vaporizer system to be available during maintenance periods. The calcite contactors will be vertical vessels and scalable with plant capacity by adding vessels in a modular fashion as demand capacity increases. The vessels will be carbon steel with NSF-approved rubber lining.
2.7.5 Final Product Water Storage and High-Service Pump Station To provide sufficient retention time for complete disinfection, product water will be temporarily stored on-site prior to being forwarded to the distribution pipeline. At present, the storage facilities will be comprised of one above ground tank with provision for a second tank, if required; each with a capacity of 5.5 million gallons. Tank capacity will be finalized (however the capacity is not expected to increase) once disinfection and finished water requirements are finalized with water off-takers, including chlorine, ammonia, and fluoride addition. The tanks will be NSF-compliant and be constructed of pre-stressed concrete. Provisions will be made in the finished water delivery system to accommodate a distribution pipeline corrosion control inhibitor, if needed, to insure the final product water is fully compatible with distribution pipeline materials of construction. Final determination for post treatment requirements will be finally determined based on operational experience and water quality characteristics required by off-takers. The product water pump station will provide high quality drinking water for distribution. Eight operating and one stand-by pumps will each have a rated capacity of approximately 1,900 gpm and be capable of discharge pressures reaching 100 psi to the distribution system. The pump bodies will be constructed of stainless steel; pipe and valves will be a combination of stainless steel, thermoplastic or lined steel based on pressure and service location. A discussion of proposed routes for pipeline delivery of product water to regional municipalities is included in Section 2.10.
2.8 Brine Concentrate Discharge SWRO concentrate will be conveyed from the SWRO site to the offshore discharge diffuser structure via dual newly constructed 36” pipelines with a brine carrying capacity necessary for the 25,000 AFY SWRO facility. Dual lines are necessary to provide redundancy during periodic pipeline maintenance, without requiring a temporary reduction in SWRO production capacity, or restricted data center cooling flow.
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The proposed brine concentrate discharge (BCD-1) pipelines will be routed subsurface from the desalination facility on Dolan Road using HDD construction from on-shore to the off-shore diffuser structure (see Figure 2.4). The pipelines will be connected to a five-jet linear diffuser oriented orthogonal to the shoreline, consisting of five discharge risers emerging from a manifold and fitted with duckbill diffuser nozzles. Alternative off-shore brine concentrate discharge (BCD) systems were also evaluated:
BCD-2: Two 36-inch diameter steel discharge pipelines would be installed from on-shore near Shaft/Pit #2 to a discharge location near the terminus of the existing oil pipeline on the north flank of the Monterey Submarine Canyon (see Figure 2.4). This alternative was included in the NOP/NOI issued on June 1, 2015 for but is no longer being considered due to the cultural/biological constraints with the on-shore routing of this alignment.
BCD-3: SWRO concentrate to be conveyed from the SWRO site to the existing MLPP cooling water outfall pipeline via dual newly constructed 36” pipeline. The concentrate discharge would be routed subsurface down Dolan Road to a location east of Highway 1 where it would connect to the existing MLPP cooling water system and co-mingle with the Dynegy’s existing seawater discharge. This alternative has several issues related to MLPP’s interest in sharing its existing discharge system with the MBRWP and also the ability for MLPP to keep its full right/access to this discharge line.
The pipelines will be connected to a five-jet linear diffuser oriented orthogonal to the shoreline, consisting of five discharge risers emerging from a manifold and fitted with duckbill diffuser nozzles located at the proposed intermediate discharge location modeled in the Brine Dilution Study (Approx 5700 Ft offshore, Appendix F). The onshore pipeline segments will be constructed of fiberglass-reinforced plastic (FRP) or similar non-metal material onshore and HDPE or flexible PVC for the offshore pipeline segments. If necessary, a discharge booster pump system will be constructed to ensure the required concentrate pressure and velocity at the discharge structure for the high velocity diffusers to operate at their design efficiency.
2.8.1 Regulatory Considerations Staff from the California State Water Resources Control Board recently developed an amendment to the California Ocean Plan in 2015 that addresses environmental issues associated with desalination facilities. One concern is the salt, minerals, and other compounds that are discharged as hyper-saline brine. Brine concentrate is denser than the receiving ocean water and, depending on discharge methods, may settle on the ocean bottom. Accumulation of brine on the seafloor may have an adverse effect on marine organisms. Currently, brine discharges from proposed desalination facilities are regulated through the issuance of National Pollutant Discharge Elimination System (NPDES) permits that contain conditions protective of aquatic life. In addition, the 2015 Ocean Plan also included provisions
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for establishing statewide requirements for use of the best available brine discharge method feasible after a facility-specific evaluation. Specifically, the preferred technology is to comingle brine with wastewater (agricultural, municipal, industrial, power plant cooling, etc) with multiport diffusors as the next best method for disposing of brine.
2.8.2 Design The outfall structure will use a multi-jet linear diffusers to ensure rapid mixing of the concentrate with the receiving water at the outfall location. The diffuser consists of five separate risers emerging from a manifold that is connected to the terminus of the concentrate discharge pipeline. Each riser will be fitted with a duckbill diffuser nozzle. Each riser will be capable of discharging a maximum of 5.45 MGD, for a combined discharge total of 27.26 MGD. Figure 2.12 depicts idealized diffuser structure.
Figure 2.12. Conceptual Diffuser Structure
The completed diffuser assembly is about 140-ft in length, 10-ft wide, and 15-ft tall. Installation will be similar to the intake structure since the diffuser pipe will be supported on prefabricated concrete pads placed on the seafloor. Please refer to the Intake and Outfall Construction Analysis for constructability details (Appendix D, forthcoming).
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2.8.3 Discharge Plume Modeling The MBRWP evaluated the ability of the proposed discharge facility to comply with the standards that are included in the Ocean Plan amendment. Scott A. Jenkins Consulting was hired to evaluate and model the initial dilution and dispersion of the concentrate discharge from the proposed Project using discharge characteristics (e.g., flow, temperature and salinity) derived from the Project design calculations. Dr. Jenkins performed hydrodynamic modeling of two proposed discharge sites to determine the potential for compliance whith what was expected to be included in the Ocean Plan Amendment at the time the work was completed. The Jenkins study involved numerical simulation of worst case and long term scenarios using a combination of hydrodynamic models: 1) a near field mixing zone model, Visual Plumes certified by the U.S. Environmental Protection Agency and the California State Water Resources Control Board for use in ocean outfall design; 2) a fully 3-dimensional far field dispersion model SEDXPORT that is a processed-based, stratified flow model with the complete set of littoral transport physics including tidal transport, wind and wave induced transport and mixing; and 3) two commercially computational fluid dynamics models (CFD) known as COSMOS/ FLowWorks for hydraulic design and Star-CD , Version 3.1, with QUICK space discretization for first order up-winding of the diffuser turbulence equations. Based on the extensive modeling, and using conservative estimates for brine discharge volumes, the probability of exceeding the discharge limits is exceptionally low for the modeled discharge design. The Jenkins report concludes that “the diffuser dilution strategy at both the deep water and intermediate MBRWP discharge sites satisfies any of the presently permitted or potential future dilution standards for all foreseeable long-term ocean conditions at MBRWP Moss Landing.” The complete Jenkins study report is provided in Appendix F. The project is proposing the intermediate location for installation of the diffusers. The Jenkins study is currently being updated to account for discharge temperature limits contained in the California Thermal Plan. The revised report will be submitted at a later date.
2.9 Operations and Maintenance The desalination plant would likely operate 24-hours a day, 365 days a year. The plant would be centrally operated from a state of the art computerized control system that would assist the plant staff in operating and monitoring the process equipment. Operators would regularly inspect equipment and conduct water quality analyses during each shift to check water quality and verify instrument readings. The types of maintenance activities and their expected frequency are shown in Table 2.4.
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Table 2.4. Summary of Maintenance Operations
Feature Frequency Duration Operation Waste Generated
Intake Screens Once per year 2 days Manual cleaning with
divers None - organic matter only
Seawater Conveyance Pipelines
Once per year 3 days Pigging to remove
accumulated sediment and bio-growth
None - organic matter only
Cartridge Filters Four times per year 4 hours Replace cartridge filter
elements
Used cartridge filter elements - non-hazardous, landfill disposal
RO membrane elements
Once every 5-years (20% annually)
Replace SWRO membrane
elements
Used SWRO membrane elements – non-hazardous, landfill disposal
Pumps As needed N/A – continuous Normal maintenance
procedures None
Valves As needed N/A – continuous Normal maintenance
procedures None
Monitoring Instruments
As needed N/A – continuous Normal maintenance
procedures None
RO Membranes Four times per year
(estimated) 1 day Chemical cleaning
pH neutralization with sanitary sewer disposal
Pretreatment Media Once every 12 years
(estimated) 7 days Replace sand media
Non-hazardous sand; land application or landfill
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2.9.1 Chemical Storage and Use Chemicals certified for use in drinking water treatment will be used in the desalination process to optimize pretreatment filtration, ensure the correct water quality, and maintain the RO membrane elements in a clean condition; as well as for stabilization and disinfection of the desalted product water for distribution in a regulated potable water supply. The chemicals used will be delivered to the site in bulk quantities and stored in fully contained bulk storage tanks prior to being used in the process. All chemical storage, handling, and feed facilities will be designed, constructed, and maintained in compliance with all applicable governmental codes and regulations to ensure safe storage and handling. Table 2.5 identifies the chemicals typically used in the SWRO process. Note: the following table is a comprehensive listing of chemical frequently used in SWRO desalination processes and does not necessarily represent that all such listed chemicals will be used in the Project. Actual chemical type, frequency and dosage used in the Project process can only be determined once experience is gained on the source water composition, quality and biological activity. Table 2.5. Chemicals used in SWRO process
Common Name Chemical Formula Feed Location
Bleach Sodium Hypochlorite NaOCl Raw Water
Bisulfite Sodium Bisulfite NaHSO3 Raw Water
Coagulant Ferric Sulfate Fe2(SO4)3-8H2O
Raw Water
Filter Aid, Cat-P Superfloc C573 Polymer Raw Water
Ammonia Aqueous Ammonia NH4OH Product Water
Caustic Sodium Hydroxide NaOH Product Water
Chlorine Sodium Hypochlorite NaOCl Product Water
Fluoride Hexafluorosilicic Acid H2Fi06 Product Water
CO2 Carbon Dioxide CO2 Post Treatment
Limestone Calcium Carbonate CaCO3 Post Treatment
Chlorine Sodium Hypochlorite NaOCl Post Treatment
Sludge Polymer Polymer Polymer Solids System
Citric Acid Citric Acid C6H8O7 Cleaning System
Polyphophate Polyphophate Polyphophate Cleaning System
EDTA EDTA C10H16N2O8 Cleaning System
SDBS Suphonate Surfactant
Cleaning System
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2.9.2 Staffing The seawater desalination facility will be designed and constructed for continuous operation and will be adequately staffed to support continuous operations in accordance regulatory requirements and good practice. The plant will be fully automated and will have operations and maintenance staff of approximately 18 full-time employees. Additionally, outside services will be required from electrical, equipment, and instrumentation contractors, and the service industry. The SWRO plant will operate 24 hours per day and seven days a week year round. Therefore, the plant will be continuously staffed with three-shifts. The daytime normal workweek shift will include approximately 5 to 7 people, depending on normally scheduled maintenance activity. The 2nd and 3rd shifts will be staffed with 3-4 people. The weekend shifts will also be typically staffed with 3 to 4 people. Some visitor traffic is also anticipated, primarily from vendors and interested parties wishing to tour the facility. On average, not more than five plant visitors weekly are anticipated. Outside service contracts will also regularly, but not frequently, visit the plant site. Such visits are not expected to exceed 1 visit per week on average.
2.9.3 Solid Waste Generation The proposed desalination plant would generate waste from the solids produced from the pretreatment process. These solids would be settled, dewatered and ultimately disposed of in a solid waste landfill or other approved land application method. The solids would contain naturally occurring organic and inorganic matter removed from the raw seawater during the pretreatment process and precipitated iron from coagulation dosing with ferric chloride, if needed. Other solid wastes generated would include used cartridge filters generated during routine maintenance activities. Spent reverse osmosis membranes are non-hazardous waste and will be disposed of in a landfill. The administrative activities at the plant would generate nominal amounts of typical office wastes.
2.9.4 Electrical Power Consumption The operating SWRO plant will consume 12-16 MW of electric power, inclusive of SWRO plant operation, source water transmission, concentrate disposal to the offshore discharge and pressurized transmission of product water to water purchaser's distribution pipeline.
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2.10 Product Water Distribution Pipelines
With a production capacity of up to 25,000 AFY, the MBRWP is designed to provide an alternative water supply to communities throughout the Monterey Bay region. Whether the MBRWP provides water to a particular community depends on whether that community or water district chooses to become an offtaker. Based on known needs and discussions with many local water suppliers, the MBRWP is including the possibility that numerous communities may choose to participate in a JPA and take water from the Project. Although any project to extend pipelines to the MBRWP would be separately proposed, permitted and constructed by the individual water suppliers, proposed pipeline routes which have been validated by potential off-takers of water against available infrastructure and likely tie in points are being included in this application.
2.10.1 Monterey Peninsula
The Monterey Peninsula Product Water Pipeline will be constructed of 36-inch diameter HDPE to deliver water south to the Monterey Peninsula communities conveying product water from the MBRWP Desalination Plant to the CAW distribution systems at Seaside. See Map below of the proposed system. The Product Water Pipeline begins at the southeast corner of Dolan Rd Tank Farm Parcel and goes 9 miles south along the UPRR through Castroville then follows the TAMC ROW to Beach Rd. in Marina. The pipeline alignment will continue in a southerly direction for 7 miles connecting with the Seaside and Monterey Pipelines just north of the intersection of Auto Center Parkway and Del Monte Boulevard.
Ownership of the pipeline and appurtenances would be shared between the JPA and CAW. The JPA will own approximately 16 miles of 36-inch diameter HDPE pipe, capable of delivering as much as 9 MGD from the MBRWP Desalination Plant to and including a CAW Meter located near the intersection of Auto Center Parkway and Del Monte Boulevard. Pipeline routes to the Monterey Peninsula are shown in Figure 2.13.
2.10.2 Castroville and Salinas
Product Water Pipelines for the City of Salinas are proposed to be routed along a parallel easement along the UPRR to a central location on Market St. near Davis Rd. to deliver approximately 6 million gallons per day of product water. A 30-inch diameter product water pipeline will exit the MBRWP east to the UPRR corridor southward approximately 12 miles to the Cal Water Salinas distribution system. This route would also have the ability to deliver water to Castroville Community Services District. Pipeline routes to Castroville and Salinas are shown in Figure 2.14.
2.10.3 Santa Cruz County Product Water Pipelines for north county Monterey and the communities of Santa Cruz County providing could transport approximately 10 million gallons per day of product water. The
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proposed route involves installing a 36-inch diameter product water pipeline that will follow an existing reclaim water pipeline, the “Purple” line to the Pajaro Valley Water Management Agency recycled water plant on Beach Rd. From the PVWMA plant the product water will be distributed to SqCWD via a 24-inch diameter pipeline north of the plant and continues along San Andreas Rd and along the SC County Coastal Rail corridor. The pipeline will terminate at the Soquel Creek Water District’s distribution system. Pipeline routes to Santa Cruz County are shown in Figure 2.15.
Figure 2.13Pipeline Route to Monterey Peninsula
Proposed Pipeline Route(s) to Castroville and Salinas
Proposed Brine Concentrate Discharge (BCD-1)
Proposed Seawater intake Location (IS-1)
Proposed Pipeline Route
Figure not to scale
Legend
Figure 2.14
Proposed Brine Concentrate Discharge (BCD-1)
Proposed Seawater intake Location (IS-1)
Proposed Pump Station
Proposed Pipeline
Figure not to scale
Proposed Pipeline Route to Santa Cruz County
Legend
Figure 2.15
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3. Data Center Overview
Data centers are low occupancy uses with few environmental impacts beyond the energy demand needed to operate and cool the computer servers. The MBRWP intends to significantly reduce the energy demand of the proposed data centers by cooling the buildings using the cold source water for the SWRO located on the same Project site. The data centers will use non-contact heat exchangers so that only heat from the data center buildings will be added to the SWRO source water. This added heat would decrease the pumping pressure needed to desalinate the seawater and thereby reduce the costs and environmental impacts of the desalination process. This cooling process will result in significant reductions in energy use and make these data center buildings among the most energy efficient data centers in the world. The MBRWP is providing independent verification of the expected gains in efficiency along with the resulting reductions in greenhouse gas emissions. More detailed information about the environmental benefits of the collocated SWRO and data centers is provided starting in Section 3.2.1.
3.1 Major Project Components
3.1.1 Data Center Buildings
The MBRWP is proposing a Data Center Complex that will have (4) buildings and a landing area-(a concrete pad and connections points for electrical and mechanical support) for a Modular Data Center. Approximately 1MM square feet of total space will be allocated for the Data Center Complex. The total Data Center Complex power load will be targeted at 150 MW. The Data Center Complex will provide the following support spaces -offices, rest rooms, kitchen and storage spaces. An area for trash and recycling will be included for the complex. The Complex will be designed and constructed with the most efficient building products as well as means and methods available.
3.1.2 Closed Loop Cooling System
Each proposed data center building will include a closed loop cooling system designed to provide air conditioning to both office and computer server areas of the buildings. In lieu of the chiller units and evaporative cooling systems typically employed for building air conditioning, the data centers will reject heat to the cold seawater being pumped to the inlet side of the SWRO facility. Cold seawater will run through a non-contact, tube-and-shell or plate style heat exchanger where it will collect heat from the data center cooling system. The heat exchanger will be made of either titanium or an admiralty metal to avoid problems with corrosion. After leaving the heat exchanger, the warmed seawater will be recombined with the SWRO inlet pipeline. The proposed seawater cooling loops will be individually monitored for both flow and temperature prior to recombination with the SWRO inlet pipeline.
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The proposed data center closed loop cooling system will hold approximately 400,000 to 850,000 gallons of fresh water for a total of approximately 2.5 million gallons for all 150MW. Prior to the initial charging, the fresh water may require treatment, such as softening and deionization, to remove hardness minerals that could result in scaling. With the initial treatment coupled with the relatively low operating temperature of the closed loop system, corrosion and scaling are not expected to be problems. Water quality will be monitored and any problems that develop will be addressed with commercially available treatment consistent with any applicable regulations. The proposed closed loop systems are not expected to consume water during normal operation. There will be incidental losses from system leaks and water will be added during operation to keep the systems fully charged. Annual maintenance may include replacing up to 20% of the closed loop system capacity with fresh, demineralized water. Water from the closed loop system, whether captured from incidental losses or maintenance procedures, will be discharged to the sanitary sewer system in compliance with any applicable pretreatment requirements. Additional information on the conceptual heat exchange design will be forthcoming.
3.1.3 Back-up Power Supply The data centers derive commercial value in part from their ability to provide customers with mission-critical space to support their servers, including access to a steady stream of high- quality electrical power supply. Interruptions of power could lead to server damage or corruption of data stored on the servers. For this reason, data center installations require careful thought and planning with respect to redundant power supplies. The MBRWP will include a set of natural gas fueled back-up power generators, either gas turbines or reciprocating engines (each retrofitted with state of the art Carbon / GHG Capture Technology), to provide the required redundant electrical power to the data centers in the case of a full or partial loss of electrical service from the grid. Additional green sources of power, including the possibility of seawater cooled rooftop-mounted solar panels, are also being considered. The back-up power generators will be located within the data center facilities themselves and anticipated to be split between the 2-3 most critical need facilities, though available for emergency power allocation across the entire project as needed. The generators being considered would each be rated between 8.5 and 10 MW. Natural gas fuel for the generators will be supplied by an existing PG&E-owned natural gas pipeline that runs across the MBRWP site and provides fuel for the Moss Landing Power Plant. California is currently producing 33% renewable energy and is expected to reach 50% by 2030. It is anticipated that at certain times of the day and year there will be abundant renewable energy available to the MBRWP. The MBRWP wishes to retain the flexibility to purchase this
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energy off-the-grid, but it is also projected that there may be massive renewable energy curtailments, especially solar, once supply reaches 40%. In the future, when solar and wind resources do not arrive as expected or weather conditions are not conducive to wind and solar production, the generators could be deployed to provide grid reliability. While providing grid reliability services, the generators would be expected to operate on average between 1 and 4 hours a day. It is expected that each generator would initially be operated no more than 1000 hours per year. If the generators are eventually transitioned to grid reliability operation, a mix of technology could include renewable, storage and conventional sources. If conventional technologies are selected, their carbon emissions will provide an opportunity to develop and demonstrate carbon capture technology. If this capture technology is successful, the project would further reduce the carbon footprint of the facility by removing the carbon produced by conventional electric generation technologies.
3.1.4 Fiber Optic Interconnections The project will interconnect with existing fiber optic cable running along the nearby Union Pacific Railway line east of the Project site. Fiber optic cable will be buried in new conduits along the routes shown in Figure 3.1.
Figure 3.1
FIBER OPTIC CONNECTION EXHIBIT
DOLAN ROADVI
A TA
NQ
UES
RO
AD
APPROX. CONNECTION POINT
APPROX. CONNECTION POINT
APPROX. CONNECTION POINT
APPROX. CONNECTION POINT
FIBER OPTIC LINE 1FIBER OPTIC LINE 1
UPR
R
FIBER OPTIC LINE 2FIBER OPTIC LINE 2
29 MAY 2014
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3.2 Overview of Operations
3.2.1 Building Efficiency Power Usage Effectiveness, or PUE, is a metric used to compare the efficiency of facilities that house computer servers. PUE is defined as the ratio of total facility energy use to Information Technology (IT) (i.e., server) power use (e.g., PUE = Total Facility Source Energy/ IT Source Energy). For example a PUE of 2.0 means that the data center must draw two watts of electricity for every watt of power consumed by the IT/server equipment. It is equal to the total energy consumption of a data center divided by the energy consumption used only for the IT equipment. The ideal PUE is 1.0 where all power drawn by the facility goes to the IT infrastructure. Data center PUE is influenced by external factors, such as average ambient temperature, and design-related factors for the buildings, cooling system, and computer servers. Most non-IT power consumption is related to air-conditioning of the computer server rooms. Most contemporary data center installations today have PUEs in the range of 1.55 to 2.5. Through a combination of building and server designs and the use of cold seawater to cool the data center buildings, the MBRWP is expecting to achieve PUEs as low as 1.06. These efficiencies would make the data center buildings among the most energy efficient in the world.
3.2.1.1 Potential for Greenhouse Gas Emission Reductions As with any large-scale project of this magnitude, it is important to recognize the potential for environmental impact and seek out opportunities to mitigate such impact wherever feasible. The MBRWP is no exception. One of the main goals of the MBRWP is to develop a sustainable solution for providing high quality potable water to the Monterey Bay region at a reasonable cost and in an environmentally sustainable way. After careful evaluation of various options, the concept of combining data centers, which have high cooling demands but which are otherwise relatively benign land uses, with a desalination plant became the obvious solution. The synergies created by this combination of technologies on a single project site are remarkable. Not only does the MBRWP significantly reduce the overall cost of providing potable water to the region compared with other proposed desalination projects, it provides benefits to the data center as well in the form of lower-cost energy, significant reductions in overall energy consumption, and, lower greenhouse gas (GHG) emissions. The reduced GHG emissions will result in the opportunity to generate carbon emission offsets, which will further reduce the overall cost of running the data centers. PE International, a firm recognized internationally as experts in sustainability, was hired to independently determine the GHG reductions possible through this combined project. The goal of this study was to quantify the difference, in terms of global warming potential (GWP), between (a) the proposed MBRWP Project to combine a SWRO with data centers and (b) a
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SWRO and separately operating, conventionally cooled data centers (i.e., not using the SWRO inlet seawater). The results of this study quantify the GWP savings realized when seawater is used to cool the data centers (in lieu of a conventional system of chillers and cooling towers) and the increased efficiency of the SWRO process resulting from the heated inlet seawater. The study found that the MBRWP’s combined SWRO and data center design results in a significant reduction in GWP compared to the alternative scenario. Within the range of possible PUEs for both scenarios (from 2.5 to 1.06), the potential annual GWP reduction from the MBRWP Project over the baseline scenario is 65.7 million kilogram (kg) of CO2e (carbon dioxide equivalent), with a large spread between a 393 million kg CO2e increase and a 603 million kg CO2e reduction depending on the chosen baseline PUE values. Over the 30-year lifetime of the facility, the influence of the difference infrastructure materials between the two scenarios on the GWP is marginal compared to the influence of power consumption on GWP. The complete PE International report is provided in Appendix G. A GHG Reduction and Minimization Study will be conducted in 2017 to evaluate how to reduce the carbon footprint of the MBRWP and make it net-carbon neutral. Potential projects may include:
o Carbon capture from on-site back-up power generators o Rooftop solar panels o Indirect free cooling, economization system for data center o Purchase 100% green power from the power provider o Purchase RECs or GHG credit o Geothermal ground loops
3.2.2 Staffing Data centers are highly automated facilities with relatively low staffing requirements. Administrative, security and maintenance staff will be present on the site on a 24-hour basis, with most staff present during normal daytime hours. During occasional maintenance activities, additional contracted resources will be needed in addition to core staff. For the combined data center buildings, core staffing is expected to require 20 employees during each 8-hour shift. Additional contracted staff and client visitors may add up to an additional 20 people during any 8-hour shift. If required, staggering shifts to avoid rush hour traffic times can easily be accommodated as most scheduled maintenance takes place during non-peak load times late at night, on weekends, or during holiday shut downs to minimize disruption.
3.2.3 Water Use and Wastewater Generation In addition to fresh water used for the closed loop cooling system, there will be potable water demand from onsite personnel. It is estimated that an average of 1500 gallons of potable
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water per day will be needed to serve the combined data center buildings. For planning purposes, it is assumed that this same volume of water will be discharged daily to the sanitary sewer system.
3.2.4 Solid Waste Generation The data centers are expected to generate solid waste typical for professional office environments. Computer servers and other electronic equipment would be recycled consistent with applicable regulations.
4. Hydroacoustic Monitoring System
4.1 Hydroacoustic System Overview
Another component of the MBRWP includes repurposing an existing, abandoned oil pipeline in the Monterey Bay to be a non-intrusive, hydroacoustic monitoring system. This system will allow for collection of real-time water quality data for the MBRWP and other research and/or academia needs that may be of interest pertaining to the Monterey Bay Canyon by utilizing a Hydroacoustic Information Link (HAIL). HAIL is a through water communications system that is nonintrusive and does not require a cabled system to relay data from offshore instrumentation. It will provide a reliable underwater data link capability for instruments located up to 10 kilometers of the system receiver.
The HAIL system is comprised of three primary components including a transmitter(s), a receiver and an onshore processor. The planned in-water instruments will monitor water turbidity, temperature, bacteria and conductivity (salinity). These four instruments will be integrated into a HAIL hydroacoustic transmitter that will send continuous data measurements on the site conditions to the HAIL Receiver. The receiver hub will be installed near the end of the existing Dynegy oil pipeline that is no longer in service. The existing pipeline will be utilized as a shore crossing conduit to install a cable that links the offshore HAIL receiver with the onshore HAIL computer processor. Figure 4.1 map shows the approximate location of the existing Dynegy oil pipeline and placement of the monitoring instruments.
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Figure 4.1 Moss Landing Project Area Site Map for HAIL monitoring System
4.2 Dynegy Moss Landing Fuel Pipeline and Installation of the HAIL System
The existing, abandoned oil Dynegy pipeline will be prepared for use as a conduit for the HAIL
system receiver. A report on the pipelines integrity is included in Appendix E. There is no
information on hydrocarbon content, it is presumed that the pipeline was cleaned prior to it
being taken out of use. As a precaution the pipeline will be checked at the sea/shore interface
and the offshore blind flange for hydrocarbons.
The first task of the cable installation will be to mobilize a shore crew to the Dynegy plant to
install the shore processing equipment and a winch that will be used to pull the HAIL receiver
cable through the pipeline. The crew will secure the cable pull-in winch in line with the end of
the inshore pipeline. The pull-in line that was previously installed through the pipeline during
the pipeline preparation phase will be attached to the winch. The onshore crew will use the
Approximate intake area & instruments
Dynegy Pipeline HAIL Receiver cable
-30m
-15m
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winch, when the offshore operation is ready, to pull the HAIL receiver cable from the offshore
installation vessel / barge, through the pipeline to shore.
Divers will be deployed to remove the end flange from the oil pipeline and recover the pull-in
wire to the vessel. The pull-in wire will be connected to the leading end of the HAIL receiver
cable and pulled to the beach by the onshore crew.
The offshore Hail receiver will be mounted on the end of the oil pipeline and sealed to prohibit
the intrusion of sand and debris. The onshore portion of the Hail receiver cable will then be
installed to the onshore processing equipment.
Additional information on the preparation of the Dynegy Pipeline and Installation of the HAIL
system is included in Appendix E.
4.3 Operations and Maintenance
Data from the offshore instrumentation will transmitted and delivered to the HAIL onshore
processor. Both the offshore instrument sensors and HAIL transmitter will be powered by
battery packs, these will need to be maintained and changed out on an ongoing basis by a small
local surface support vessel.