The Monterey Peninsula Water Management District (MPWMD) is proposing to construct and operate a desalination plant with a production capability of 8,400 acre-feet annually (AFA) in Monterey County, California. The desalination plant would be located in Sand City. Other major elements of the project, including pipelines, seawater collection wells, and brine disposal wells, could be located in Seaside, Monterey, Marina, and the former Fort Ord, depending on the options selected.
The MPWMD manages and regulates the use, reuse, reclamation, and conservation of water within its boundaries on the Monterey Peninsula. About 80% of the water collected, stored, and distributed within the MPWMD boundaries is done so by the California-American Water Company (Cal-Am), which serves approximately 95% of Monterey Peninsula residents and businesses. Approximately 70% of the water delivered by Cal-Am is diverted from the Carmel River Basin. In 1995, the State Water Resources Control Board (SWRCB) determined that the Carmel River was over-appropriated in the drier seasons of the year and issued Order WR 95-10 to reduce Cal-Am’s unlawful diversions from the Carmel River.
The proposed 8,400-AFA desalination plant, also referred to as the MPWMD water supply project (WSP), would allow Cal-Am to meet the provisions of SWRCB Order WR 95-10, maintain its existing total system production of 15,285 AFA (maximum, dry year demand), and continue to provide a reliable supply of water to the Monterey Peninsula customers.
The MPWMD’s objective for the proposed project is to assist Cal-Am to develop a legal water supply, thus the production goal of 8,400 AFA. While meeting this objective, the MPWMD is also working to protect the quality of surface and groundwater resources, continue the restoration of the Carmel River environment, manage and allocate available water supplies, promote water conservation, and plan for future water supply needed to meet community and environmental needs.
This environmental impact report (EIR) is being prepared in compliance with the California Environmental Quality Act (CEQA), which applies to a discretionary activity proposed by a California public agency. This EIR analyzes the environmental impacts of the proposed project, identifies ways to reduce or avoid adverse environmental impacts resulting from the project, identifies and assesses alternatives to the proposed project, and assesses cumulative impacts.
The proposed project is an 8,400-AFA desalination plant in Sand City. The desalination plant would use the reverse osmosis (RO) process to remove salts from seawater. This process is about 50% efficient; therefore, the desalination plant would require 15 million gallons per day (mgd) of feedwater to produce 7.5 mgd of potable water. At the same time, the plant would produce about 7.5 mgd of brine concentrate that would be returned to the ocean. The project elements include the following:
n Desalination plant located at one of three sites within Sand City (Figure ES-1). Desalination Plant Site 1 is located on a parcel currently occupied by Graniterock. Desalination Plant Site 2 is the existing Salvation Army building located between California Street and Scott Street. Desalination Plant Site 3 is located on a parcel west of and adjacent to State Route 1 (SR 1) near the intersection of SR 1 and Del Monte Boulevard.
n Seawater collection through horizontal directionally drilled (HDD) wells and/or radial beach wells located along the beach in Sand City and the former Fort Ord (Figure ES-1 and ES-2).
n Brine disposed of through HDD wells located within the coastal section of former Fort Ord or through the Monterey Regional Water Pollution Control Agency (MRWPCA) treated-wastewater outfall pipeline, which discharges to Monterey Bay south of the mouth of the Salinas River (Figure ES-3, ES-4a, and ES-4b). If the MRWPCA brine discharge option was selected, brine would be disposed of in the outfall year-round.
n Seawater collection pipeline and treated-water pipelines constructed primarily within city streets (Figure ES-5).
n Brine disposal pipelines to HDD wells or to the MRWPCA wastewater outfall constructed within surface streets or railroad rights-of-way.
The proposed project could be expanded in the future by constructing additional seawater collection wells and increasing the capacity of the RO equipment.
Alternative 1—No Project
Two “no-project” scenarios are analyzed under this alternative. Under the first scenario, the proposed desalination plant would not be built. Cal-Am would continue to supply up to 15,285 AFA total system production. Pumping from the Carmel River Basin would continue to be limited to 11,285 AFA, and production from the Seaside Basin would continue to be a maximum of 4,000 AFA. This reflects the SWRCB temporary limits on the amount of water that can be diverted from the Carmel River Basin until a replacement source is developed.
Under the second no-project scenario, no new water supply project would be pursued by Cal-Am or MPWMD and, as a result, the SWRCB would fully enforce Order WR 95-10. In Order WR 95-10, the SWRCB stipulates that Cal-Am only has legal right to divert up to 3,376 AFA from the Carmel River. Order WR 95-10 also stipulates that Cal-Am either obtain a permit from the SWRCB to divert the unlawful amount from the Carmel River or replace that amount from some other water source. This scenario assumes that Order WR 95-10 is enforced and no more than 3,376 AFA is diverted by Cal-Am from the Carmel River prior to developing a replacement supply of water. A maximum diversion of 4,000 AFA is assumed for a total Cal-Am production of 7,376 AFA.
Alternative 2 is composed of an aquifer storage and recovery (ASR) system and a desalination plant at Sand City to produce 8,400 AFA. The ASR element would include diverting surplus flows from the Carmel River (3,200 AFA) and storing this water in the Seaside Groundwater Basin. The stored water would be withdrawn from the basin during peak demand periods, typically summer months. Major elements of the ASR would include five new extraction wells in the Carmel Valley with a production capacity of 1,800 gallons per minute; a 13-mgd water treatment plant; 11 injection and recovery wells within the former Fort Ord; and new pipelines connecting the extraction wells to water treatment plants and the water treatment plants to the injection and recovery wells.
The desalination plant element would be similar to the proposed project, except production would be limited to 5,200 AFA or approximately 4.6 mgd. Similar to the proposed project, the desalination plant would be located in Sand City, and the seawater collection wells would be located on or near Seaside Beach and/or the former Fort Ord. Brine would be disposed of through HDD wells or through the MRWPCA outfall.
Alternative 3 would include a new dam and reservoir on the mainstem of the Carmel River. The reservoir would be located 24 miles upstream from the mouth of the Carmel River, and the dam would be located approximately 2,400 feet downstream of Los Padres Dam. Like the Carmel River Dam project proposed by Cal-Am in 1996, the 282-foot-high gravity dam would be constructed with roller-compacted concrete and would have a spillway and fish collection facilities; the reservoir would have a storage capacity of approximately 24,000 AF, a surface elevation of 1,130 feet above sea level, and a surface area of 266 acres. The reservoir project described in previous evaluations would be combined with other Cal-Am facilities to achieve various production goals. However, for the purposes of this analysis, production from the reservoir would not exceed 8,400 AFA to enable comparison to the proposed project.
Alternative 4 would involve construction and operation of an 8,400-AFA desalination plant located adjacent to Duke Energy’s Moss Landing Power Plant (MLPP). This alternative includes an RO desalination plant, pump stations, water storage tanks, and pipelines connecting the desalination plant to the existing Cal-Am water distribution system. Alternative 4 would be similar to the plan described in the California Public Utilities Commission Final Plan B Project Report (California Public Utilities Commission 2002). However, the desalination plant described in the Plan B Project Report would produce 9,400 AFA, whereas production under Alternative 4 would be 8,400 AFA for the purposes of this analysis to enable comparison to the proposed project. Unlike the Plan B project, Alternative 4 would not include the Carmel River ASR.
The MPWMD planning process that has culminated in the development of the proposed project included significant input from the MPWMD Board of Directors, government agencies, and the public regarding water production goals. Through that process, MPWMD determined that its project should focus on the facilities and production level needed to make the current community water supply a legal supply. Larger production levels that may be needed to serve existing legal lots of record and future growth were discussed and have been described in project-related documents and in public meetings. These larger production goals are described in concept, but are not discussed in detail and not subjected to environmental evaluation in this EIR because a larger planning process and public discourse is needed to more fully describe the goals and the facilities requirements of expanded water production. The alternative water supply projects described above were developed with the knowledge that future community decisions could warrant expansion of facilities to meet additional water production goals. If facilities expansions are proposed in the future, those actions would be subject to further environmental evaluation in compliance with CEQA.
Environmental impacts of the proposed project and the mitigation measures required to reduce the significant impacts to a less-than-significant level are listed by issue area in Table ES-1 at the end of this Executive Summary. Following is a brief discussion of the impacts for each issue area (presented in the order they appear in the EIR). For a comparison of the options within the proposed project, refer to the summary comparison tables at the end of each technical chapter in the EIR.
Construction of the desalination plant, wells, and pipelines would result in increases in NOx and PM10 emissions. This impact would be mitigated to a less-than-significant level with emission-reducing construction practices.
Operation of the project would result in potential exposure of sensitive receptors near the desalination plant to toxic air contaminants (chlorine) from the desalination process. This impact is considered less than significant because of the Monterey Bay Unified Air Pollution Control District’s Regulation 10 requirements. This regulation would require the desalination plant to use a closed-loop chlorination system that minimizes the potential for release of toxic chlorine gas.
Construction of the proposed project could affect special-status plant and wildlife species or habitat in undeveloped dune areas. These special-status species include the federally listed sand gilia and Monterey spineflower plant species; the federally listed Smith’s blue butterfly, black legless lizard, western snowy plovers, and burrowing owl wildlife species; and several nonlisted special-status plant species (see discussion below for each project component). These impacts would be mitigated to a less-than-significant level with construction surveys that allow avoidance, construction timing, and habitat restoration and replacement.
Operation of the proposed project would have a beneficial impact on riparian habitat along the Carmel River because river flows would increase. However, the increased flows could have a potentially adverse effect on the existing populations of California red-legged frogs (CRLF) because freshwater increases could result in an increase in the number of nonnative bullfrogs, which are a competitor and predator of CRLF. This impact would be mitigated to a less-than-significant level by continuing or expanding bullfrog eradication efforts currently in place.
Desalination Plant. Construction of the desalination plant at site 1 would have no significant effects on biological resources because the site is currently developed with Graniterock facilities. However, construction of the desalination plant at sites 2 and 3 could affect federally listed special-status plant and wildlife species or their habitat and nonlisted special-status plant species because these sites include currently undeveloped sand dunes. At plant site 2, special-status species include sand gilia and Monterey spineflower, and Smith’s blue butterfly and black legless lizard. At plant site 3, special-status species include sand gilia, Monterey spineflower, and black legless lizard. Additionally, development at plant site 3 could result in the disturbance of breeding or wintering western snowy plovers and temporary disturbance to nonlisted special-status status plant species. These impacts would be mitigated to a less-than-significant level through construction timing and by replacing habitat with off-site restoration.
Seawater Collection. If radial wells are constructed to collect seawater, there would be temporary disturbance to western snowy plovers at Seaside Beach. This impact would be mitigated to at less-than-significant level with preconstruction surveys and appropriate construction timing. If HDD wells are constructed, there could be temporary impacts on sand gilia, Monterey spineflower, nonlisted special-status plant species, Smith’s blue butterfly, black legless lizard, and western snowy plovers. These impacts would be mitigated to a less-than-significant level through construction timing and by replacing habitat with off-site restoration.
Brine Disposal. If HDD wells are constructed at the former Fort Ord to dispose of brine, there could be impacts on sand gilia, Monterey spineflower, Smith’s blue butterfly, and black legless lizard, as well as temporary disturbance to western snowy plovers, and burrowing owl habitat. If the MRWPCA outfall pipeline is constructed, there could be impacts on fewer special-status species (federally listed Smith’s blue butterfly and black legless lizard), but the effects could occur over a larger area because of the length of the pipeline. Additionally, for both the HDD well sites and the MRWPCA pipeline, there could be temporary disturbance to nonlisted special-status plant species habitat. These impacts would be mitigated to a less-than-significant level primarily by on-site/off-site restoration.
Treated-Water Conveyance. Impacts on biological resources would be minor because most of the pipelines would be installed beneath paved roadways where there are few, if any, biological resources.
Construction could result in “frac-out” during subsurface drilling of wells and pipelines. Frac-out is a term used to describe the fracture or cracking of soil or rock above an active subsurface drilling operation, leading to discharge of drilling fluids to the surface. The drilling mud proposed for this project would be composed of the lubricant bentonite and fresh water. This mud could seep up through a fracture to the floor of Monterey Bay and have an adverse effect on benthic (bottom-dwelling) species. This impact would be reduced to a less-than-significant level by implementing best management practices (BMPs) and ensuring that drilling is halted if frac-out occurs. Drilling would not be restarted until the fracture is sealed.
If brine disposal were to occur through HDD wells, operation of the project would result in brine discharge into the Older Dune/Aromas Sand formation (Aromas formation) under the seafloor of Monterey Bay. The impact on Monterey Bay aquatic resources is considered less than significant because brine discharged into the formation below the bay would move downward rather than upward toward the seafloor environment. This movement is anticipated because the brine would be denser than the seawater present in the formation. If the MRWPCA outfall was used for brine disposal, the impact on marine species would be less than significant because modeling indicates there would be adequate dilution. Any changes in sedimentation patterns at the outfall would be minor and would not significantly affect benthic species.
Project implementation would result in increased flows in the Carmel River, and this could have a positive effect on the river’s aquatic resources in comparison to the existing conditions. However, this change would not return Carmel River flows to the “natural” condition that existed before humans altered streamflow and groundwater in the river basin.
Implementation of the project would result in potential for discovery of buried cultural deposits and human remains during construction of the wells, pipelines, and desalination plant. This impact would be mitigated by “stop work” orders if buried cultural deposits or human remains were encountered during construction activities and appropriate recovery or avoidance procedures were implemented.
There would be no operational impacts on cultural resources.
Construction of the project would disturb the ground and expose soil to rain and wind, potentially causing accelerated erosion and deposition of sediment into drainages. Development of a stormwater pollution prevention plan (SWPPP) and implementation of its recommendations would protect receiving waters, so the impact would be less than significant. Additionally, construction of the radial wells within 50 feet of the 50-year erosion setback line could increase slope instability. This impact would be mitigated to a less-than-significant level by implementing bluff erosion control measures.
Operation impacts include potential structural damage to the desalination plant and associated pipelines and wells from seismic activity and rupture of pipelines from soil expansion, both of which could threaten public safety. These impacts are considered less than significant because all structures would be designed to meet the Uniform Building Code and California Building Standards, and the pipeline would be designed and located in compliance with recommendations identified in the engineering geotechnical investigation.
Construction of the project could result in increased erosion and sedimentation, the potential for frac-out during subsurface drilling, and disposal of dewatering effluent. These impacts would be reduced to a less-than-significant level because there would be a requirement to comply with BMPs and other conditions set forth in the SWPPP and associated permits. There would be a slight increase in impervious surface and a resulting increase in runoff containing contaminants where the desalination plant is constructed, but this is considered less than significant because the small amount of increased runoff would not substantially alter drainage patterns, and runoff control measures would be taken to maintain water quality.
The potential for operational impacts related to disposal of filter cleaning solutions to the sanitary sewer system would be maintained below significance thresholds through pretreatment, if necessary. Risk of upset, such as pipeline failures, would be minimized through proper facility design, construction, and contingency plans.
Operation of the project could result in changes to hydrology and water quality from seawater collection and brine disposal, but these potential impacts are considered less than significant (see below). Additionally, project-related increases in flows in the Carmel River would likely result in a small increase in the transport of sediment in the lower stretch of the river. This is considered less than significant because of the small size of the change in sediment movement. The small change in sediment transport is not anticipated to substantially reduce bank stability or flood conveyance capacity.
Seawater Collection. Operation of radial or HDD collection wells would result in a less-than-significant impact on groundwater hydrology and water quality. Water would be withdrawn from a portion of the Seaside Groundwater Basin that is small, geologically isolated, unused, and exhibits significant constraints to future use. There is a remote possibility that water withdrawal from the aquifer could result in a drawdown of Robert’s Lake because the lake is hydraulically connected to the water supply source aquifer. This potential impact would be reduced to a less-than-significant level by monitoring the lake’s water level and, if necessary, augmenting the water going into the lake.
There also is a possibility that the project-related groundwater pumping would affect the saltwater/freshwater interface within the Aromas formation in the vicinity of the wells. This interface could be moved toward the bay, which could result in water with a lower salinity being drawn by the wells in the future. This lowering of feedwater salinity would reduce the need for salt removal and would, therefore, increase the desalination plant’s efficiency. This change would not be considered an adverse impact.
The potential reduction in Robert’s Lake water level or movement of the saltwater/fresh water interface would be greater with operation of the radial wells than with HDD wells. The screened portion of the HDD wells would be located farther oceanward than would the screened portion of the radial wells; as a result, the HDD wells would have a greater effect on interactions with the ocean than with the freshwater inland aquifer.
The northernmost HDD extraction well would be located offshore of a portion of the Seaside Groundwater Basin that is used for domestic purposes. However, the potential for this extraction to affect domestic water use would be very low because of the small amount of water that would be drawn by the well and the relative isolation of the well from the more inland and much deeper aquifers tapped by water supply wells in the area.
Brine
Disposal. If HDD brine disposal
wells were to be constructed, the impact on local groundwater and hydrology
would be less than significant. Once
the brine was discharged into the subsurface Aromas formation, it would tend to
move lower into the formation because the brine would be denser than the
saltwater that exists within the aquifer.
The potential that the brine would migrate upward to the floor of the
bay or inland toward the freshwater portions of the aquifer would be extremely
remote. Further, the aquifer containing
the brine would receive a constant influx of ocean water from above and, at
some point, would be diluted to the point that it would not be substantially
more saline than ocean water once reaching the ocean floor. No mitigation is required.
If the MRWPCA outfall were to be used for brine disposal, the impact would be less than significant. Modeling of this combined brine and wastewater discharge indicates that there would be adequate dilution to prevent significant changes in ocean salinity or concentrations of trace pollutants. Also any changes in sedimentation patterns at the outfall would be minor and would not significantly alter water quality. Modeling conducted for an earlier desalination project proposal showed that, even with 80–100% wastewater reclamation at the MRWPCA treatment plant, the combined plant discharge would still be only slightly more saline than the ocean following initial dilution. This analysis was conducted using conservative estimates of mixing zone volume and dynamics.
There is some potential that the brine from the desalination facility could interact with the wastewater and cause dissolved particles to flocculate and become suspended particles, changing sedimentation patterns around the wastewater outfall. This potential impact is considered less than significant given the large area over which the effluent plume would disperse. The concern that toxic levels of contaminants might exist in mixed brine/wastewater treatment plant effluent could be addressed only through pilot studies. MPWMD proposes that an appropriate management/remediation strategy would be developed if pilot studies indicated a potentially significant change in water quality would occur from mixing the desalination project brine with MRWPCA wastewater.
Construction activities would temporarily disrupt land uses adjacent to the treatment plant site, the well sites, and along the pipeline corridors. These effects would be less than significant because of their temporary nature. Also, required traffic control plans would be designed to mitigate circulation impacts, including measures to maintain pedestrian and bicycle access and circulation during project construction. Effects on the Monterey Coast Trail would be controlled in this manner.
Location of the desalination plant at Plant Site 3 would be inconsistent with the applicable land use designation and zoning for the proposed parcel. The project would convert open space that is designated for recreation and planned for future residential development to a more industrial/public facility use. The project is not required to comply with local zoning, per California Government Code Sections 53091 and 53096. These sections exempt the “location or construction of facilities for the production, generation, storage, treatment, or transmission of water” from regulation under local zoning ordinances. As such, operation of the collection and disposal wells, collection and disposal pipelines, and desalination plant would have a less-than-significant impact on applicable land use plans, policies, or regulations.
Construction of the proposed project facilities would expose noise-sensitive land uses to higher-than-normal noise levels. This condition would be of greatest concern where construction occurs in or adjacent to public recreation areas such as Seaside Beach. This impact would be mitigated to a less-than-significant level by limiting hours of construction and employing noise-control construction practices.
Operation of the desalination plant, which involves three 3,500-hp electric pumps, could expose adjacent noise-sensitive land uses to noise levels above the local noise standards. This would be mitigated to a less-than-significant level by designing the pump stations to meet local noise standards.
Construction of HDD wells and installation of pipelines that extend through the former Fort Ord could expose employees and the public to hazardous materials because various organic substances, metals, petroleum products, and related chemicals may be present in the soil. This impact would be reduced to a less-than-significant level by preparing a health and safety plan and risk management plan for construction activities on the former Fort Ord and then implementing the feasible PM10/dust–control measures, worker safety training, and public access controls during construction activities.
Operation of the desalination plant would involve the storage and use of hazardous materials, including carbon dioxide, lime, chlorine gas, and other substances, that may result in hazardous conditions on site. Compliance with regulations and requirements concerning the use and storage of hazardous materials would minimize the proposed project’s potential to threaten public safety and the environment.
Construction of the desalination wells, pipeline, and plant could result in increased solid waste and construction debris being left at the construction sites or on roadways. This impact would be reduced to a less-than-significant level by ensuring proper disposal of all demolition and construction debris and by sweeping roadways and parking lots. Construction could also result in the temporary disruption of existing utilities and utility service, particularly underground utility lines in roadways but possibly aerial lines as well. This impact would be mitigated to a less-than-significant level by coordinating relocation and interruptions of service with utility providers and by protecting all existing utilities slated to remain.
Operation of the desalination plant would increase the demand for electricity. Pacific Gas and Electric Company (PG&E) can provide adequate electricity for operation of the desalination plant.
Construction of the pipelines, wells, and desalination plant would result in temporary increases in traffic, which could further degrade traffic movement at intersections or roadways already operating at unacceptable levels of service (LOS). Additionally, construction activities associated with installation of pipelines could disrupt fixed-route transit service and cause schedule delays to Monterey-Salinas Transit (MST) and disrupt service on the Union Pacific Railroad (UPRR) line. These impacts could be mitigated to a less-than-significant level by coordinating with local agencies to prepare a traffic control plan during the final stage of project design.
Operation and maintenance of the desalination plant would require approximately five employees at any given time, which would result in a less-than-significant increase in traffic and demand for parking near the treatment plant site.
Construction activities would temporarily alter scenic views identified in the local general plans and local coastal programs and would affect views from SR 1, a state-designated scenic highway. This impact is considered less than significant because construction activities are considered temporary, and the existing visual character of areas surrounding the project sites would be restored after the completion of the project.
There could be operation impacts on visual resources at the HDD well sites and Desalination Plant Sites 2 and 3 from the introduction of new visual features in currently undeveloped areas. This impact would be mitigated to a less-than-significant level by providing vegetative buffers, minimizing visually intrusive fencing, and ensuring the architecture and site design of the desalination plant are consistent with the existing dunes environment. Additionally, the desalination plant would create a new source of light and glare for surrounding areas. This impact could be mitigated to a less-than-significant level by incorporating light-reduction measures into the plan and design of exterior lighting at well sites and desalination plant sites.
The project’s construction-related impacts that could contribute to a cumulative effect include increased traffic, dust emissions, noise, and loss of vegetation and wildlife habitat. To minimize cumulative effects on traffic, air quality, and noise, construction projects planned for the same timeframe should be coordinated to implement compatible traffic control plans, phase construction activities so the NOx and PM10 emissions remain below Monterey Bay Unified Air Pollution Control District (MBUAPCD) thresholds, and implement noise reduction measures for all projects. However, because there is no guarantee that the other local agencies will participate in implementing the cumulative impact mitigation measures, cumulative impacts are considered significant and unavoidable. To minimize cumulative effects on vegetation and wildlife (loss or disturbance to special-status plant and wildlife species or their habitat), preconstruction and postconstruction biological surveys will be conducted for special-status plant and wildlife species and their habitat for projects affecting undeveloped dune habitat; any losses will be compensated for, and construction monitoring will be conducted.
The project’s operation-related impacts that could
contribute to a cumulative impact include effects on Monterey Bay’s water
quality and aquatic resources.
Additionally, in the vicinity of the desalination plant, there could be
increased traffic from employees and noise from facility operation. It was determined that the project would not
result in a substantial contribution to decreased water quality and significant
adverse effect on aquatic resources in Monterey Bay from brine disposal because
the brine would be sufficiently diluted.
Increased traffic from employees could contribute
to cumulative effect of level of service (LOS) degradation at intersections
operating at or below acceptable levels.
To reduce this impact to a less-than-significant level, employees will
avoid critical intersections during peak hours.
Chapter 16, “Alternatives,” provides the results of the comparative evaluation of the environmental effects of Proposed Project with the alternatives, including the No-Action Alternative. The environmental impacts associated with constructing and operating the alternatives are generally greater than the Proposed Project with the exception of the No-Action Alternative.
Two No-Action Alternative scenarios were evaluated. One scenario assumed current Cal-Am diversions of up to 11,285 AFA from the Carmel River would continue. The other scenario assumed that SWRCB Order WR95-10 would be fully enforced, resulting in Cal-Am diversions of up to 3,376 AFA; however, this loss in water supply would not be replaced. Both scenarios would not result in construction-related effects because no water diversion, treatment, or transmission facilities would be constructed. If current diversions continue, the existing adverse effects on Carmel River aquatic resources and visual resources would continue. If only 3,376 AFA is diverted from the river by Cal-Am, beneficial effects on the Carmel River resources would occur, but may also result in adverse impacts on alternative water supplies such as the Seaside Groundwater Basin. This loss of water supply may also result in adverse effects on the local and regional economy.
Alternative 2 includes a desalination element and an aquifer storage and recovery (ASR) element. The components of the desalination element would be similar to the Proposed Project. Construction and operation effects of the desalination element would be similar but less than the Proposed Project because fewer wells would be constructed and less brine would be discharged. The ASR element results in greater impacts on riparian vegetation, oak woodlands, upland chaparral, coastal chaparral, and maritime chaparral than the Proposed Project as a result of construction and operation of water conveyance pipelines between the Carmel River and the Seaside Groundwater Basin and injection and extraction wells on the former Fort Ord. Benefits to the Carmel River resources due to reduced diversions would be similar to the Proposed Project.
Alternative 3 includes construction and operation of a dam on the Carmel River near the existing Los Padres Dam. The project would result in greater construction-related impacts on air quality, noise, cultural resources, and water quality than the Proposed Project because a greater area would be disturbed. Permanent impacts on vegetation and visual resources would be greater because of inundation effects. Benefits to the Carmel River resources, due to changes in enhanced streamflow would be less than the Proposed Project, because of continued diversions in the lower river.
Alternative 4 consists of a desalination plant located at Moss Landing. Constructing this alternative would result in greater impacts on air quality, vegetation, wildlife, cultural resources, and water quality because of the length of the proposed pipeline. Operational impacts would be similar to the Proposed Project, but Alternative 4 would likely have fewer effects on the Monterey Bay environment. Benefits to the Carmel River resources would be similar to the Proposed Project.
The State CEQA Guidelines require identification of an environmentally superior alternative that would minimize adverse impacts on the project site and surrounding environment, while achieving the project’s basic objectives. The goal of identifying the environmentally superior alternative is to assist decision makers in considering project approval, although an agency is not required to select the environmentally superior alternative (Laurel Hills Homeowners Association v. City Council [1978] Cal. App. 3d 515, State CEQA Guidelines Sec. 15042-15043). The No Project Alternative cannot be selected as the environmentally superior alternative.
A discussion of the comparative environmental impacts of the Proposed Project and the alternatives is included in Chapter 16, “Alternatives.” The MPWMD has identified the Proposed Project composed of the Site 1 desalination plant, HDD seawater collection wells, HDD brine disposal wells, and the treated water pipeline following the Del Monte Avenue alignment as the environmentally superior alternative.
Between the different seawater collection options (HDD wells and radial wells), brine disposal options (HDD wells and treated wastewater ocean outfall), desalination plant locations, and treated water pipeline alignments (Del Monte Avenue and Fairmont Street), the HDD/site 1/Del Monte Avenue combination would result in fewer construction-related and operation-related environmental effects. Constructing the HDD seawater collection wells would result in less ground disturbance than the radial wells and would minimize adverse effects on sensitive habitat and special-status-species. Because the HDD wells are located farther offshore than the radial wells, changes in the onshore characteristics of the aquifer attributable to pumping would be minimized. Using HDD wells for brine disposal would substantially reduce the length of the brine disposal pipeline compared to the MRWPCA outfall option. Choosing this brine disposal option would result in fewer ground-disturbing activities. In addition, disposal of brine within this aquifer would avoid effects on aquatic habitat as a result of discharging brine through the outfall. Selecting desalination plant site 1 would avoid impacts on sensitive plant habitat and visual resources and would be more compatible with adjacent land uses because this site is located on a parcel used for industrial purposes, whereas sites 2 and 3 include these habitats.
The Proposed Project is the environmentally superior alternative when compared to Alternatives 2 through 4. Construction-related effects would be less when compared to the alternatives because fewer ground-disturbing activities would occur. Resulting construction-related effects on water quality, sensitive plant and wildlife habitat, air quality, and cultural resources would be less compared to all alternatives. Construction-related effects on transportation and circulation would be the same or less than the alternatives. Operation-related effects would be less than all alternatives because less land would be permanently converted and most facilities would be located underneath roadways or constructed in disturbed areas. Water quality effects would be avoided because brine would be discharged in an offshore aquifer.
The construction and operation of the proposed project is controversial because of competing environmental, municipal, and public uses of water and land in the Monterey Peninsula region and because of concerns for the effects of desalination facilities on marine life, coastal sensitive habitats, and Monterey Bay water quality. During the scoping process for the EIR, the major areas of concern identified included:
n effects on flows in the Carmel River and resulting effects on the watershed ecosystem (including effects on protected species such as steelhead and CRLF);
n water quality impacts on the Monterey Bay National Marine Sanctuary and effects on fish and marine wildlife;
n the appropriate size for a new water supply project (should the project provide just enough water to comply with SWRCB Order WR95-10, or should it include an increment for future growth?);
n pursuit of a regional water supply project versus a project designed to meet only the needs of MPWMD water users;
n water quality and water quantity impacts associated with aquifer storage and recovery in the Seaside Groundwater Basin;
n consideration of the CPUC Plan B alternative (desalination plant at Moss Landing); and
n consideration of the Carmel River Dam and Reservoir Project, which was a proposed project during the EIR scoping period but has since been dismissed by MPWMD and the CPUC.