Salton Seawater Marine Habitat Demonstration

Transcription

1 Imperial Irrigation District Proposal for a Salton Seawater Marine Habitat Demonstration Point of Contact: Bruce Wilcox Environmental Manager Water Transfer Imperial Irrigation District Operation Headquarters J E. Barioni Boulevard Imperial, CA Tel: Cell: Fax:

2 Technical Proposal Demonstration Project The Salton Seawater Marine Habitat Demonstration project will evaluate an innovative use of an existing but underutilized technology, a Salinity Gradient Solar Pond, to distill hyper-saline post agricultural water from the Salton Sea. This pure water will supply and maintain a Marine Habitat Pond to demonstrate replacement of soon to be lost marine habitat at the Salton Sea in areas where water supply for habitat is not available. Applicant Background The Imperial Irrigation District (IID) currently has water rights to supply from the Colorado River capped at 3.1 million acre-feet per year, minus urban water transfers. IID has senior rights to about 2.6 million acre-feet per year delivered in it s service territory, the Imperial Valley in California. Due to a 3in/year average annual rainfall in this desert region, local surface water supplies are very limited. The vast majority of water needs for most users in the Imperial Valley are supplied from Colorado River Water delivered through the All American Canal and managed by Reclamation. The IID owns large tracts of presently submerged land on the South shore of the Salton Sea that will be exposed and may be ideal for solar energy development by the technology proposed for this demonstration. Use of Salinity Gradient Solar Ponds for Salton Sea distillation and salinity management was described in Project Proposal 42 in IID s Integrated Water Resources Management Plan. Project Objectives The larger objective is to develop a cost effective method to provide long term contaminant free water supply by distillation to shallow marine habitat ponds at this or any location on soon to be exposed Salton Sea lakebed. By using only locally available post agricultural Salton Sea water, Colorado River water used to support habitat projects can be conserved for other uses. The water reclamation method demonstrated will use a Salinity Gradient Solar Pond to capture and store thermal energy for distillation of Salton Seawater and recycling of marine habitat pond water. An existing Salton Seawater desalination test plant that uses low pressure geothermal steam as the energy source will be demonstrated to establish initial target salinity in both ponds. The Salinity Gradient Solar Pond will receive all brine from desalination by solar or geothermal energy thus controlling salinity in the system without brine discharge. Surface films and non-toxic molecular monolayers will be tested to reduce evaporation losses in both habitat and solar ponds reducing costs and further conserving makeup water from the Salton Sea. The primary objective of this demonstration project is to evaluate cost, energy, and water treatment requirements that will enable Salinity Gradient Solar Ponds to provide all the energy, water treatment, and salt storage needs for the creation and maintenance of Marine Habitat Ponds anywhere on future Salton Sea dry lakebed without the need for fresh or brackish water from canals, rivers, or drains hence conserving those supplies. A key added benefit is to eliminate fugitive dust emissions from any critical areas by covering dry Salton Sea lakebed with habitat and solar ponds. Specific Research Objectives This Project will develop and pilot test an alternative model for creating expandable, sustainable shallow marine habitat ponds at the Salton Sea. The marine habitat aspect of the concept is modeled on holding a microcosm of the existing Salton Sea terminal lake ecosystem at a water quality suitable for

3 the current wildlife population. The Salton Sea has minimal outflow from seepage and suffers a high rate of water loss to evaporation causing gradual concentration of salts and contaminants in the brackish inflow. A marine habitat pond filled with Salton Sea water could be maintained indefinitely at target salinity without accumulation of selenium or other contaminants by replacing water lost to evaporation and seepage with distilled water. A limited inflow may be needed to supply essential nutrients to support biota, offset by a limited outflow or by seepage alone. The cost of replacing evaporation losses with distilled water is generally assumed to be prohibitive due to high energy costs. However, these costs can be substantially reduced by using available products to reduce evaporation losses and by taking advantage of the uniquely rich renewable energy resources the Salton Sea region offers. This Project will test the use of films and non-toxic monomolecular layer products to reduce evaporative losses. Use of both non-commercial geothermal steam and a salinity gradient solar pond will demonstrate low cost heat energy to drive a distillation process. Distilled Salton Sea water will maintain a shallow marine habitat pond. Several specific questions need to be answered 1. How effective are the available products for evaporative control when applied to Salton Seawater? The products on the market are designed for pools and reservoirs and may perform differently with marine water. 2. Is geo-cooling in the playa adjacent to the ponds a viable option to cool the thermal desalination process? Thermal desalination and electric generation from salinity gradient solar ponds have been cooled by an evaporative loop through the pond surface. Evaporative cooling would increase water use. Geo-cooling would be more beneficial if cost effective. 3. How much seawater or brackish inflow, if any, is needed to supply essential nutrients to a shallow marine habitat pond? The Salton Sea is eutrophic, often suffering from excessive nutrient inflows. A lower level of nutrients is probably healthy for a pond ecosystem. An optimum needs to be determined. 4. Is outflow over and above seepage needed and, if so, how much? 5. How well will a salinity gradient solar pond perform on the Salton Sea playa? Extensive data is available on these ponds in other locations. But, the thermal efficiency depends on local insolation, seasonal temperatures, heat loss through soils under the pond, wind disturbance of the salinity gradient, and impacts of airborne algae and dust on light transmission into the pond. Only local testing can provide data on these factors. 6. Will there be negative impacts from co-locating shallow marine habitat and salinity gradient solar ponds? These could include algae, fish, birds, etc. from the habitat pond interfering with the clarity or gradient stability of the solar pond, or heat impacting the shallow saline habitat pond. 7. What special pond construction methods will be needed on the Salton Sea playa? Few construction projects have been carried out there. Those who've done it warn of heavy equipment sinking rapidly into the muck. 8. What is the cost per acre of an integrated shallow marine habitat and salinity gradient solar pond system? This can be crudely estimated from other locations, but the climate, hydrologic, and environmental conditions at the Salton Sea are unique. Both pond systems are very sensitive to these conditions. A local demonstration will quantify the amount of make-up water needed and the cost to distill it, as well as other construction, water management, and wildlife management costs.

4 Description of Technical Work The Salton Seawater Marine Habitat Demonstration will develop a process for reclamation of hypersaline water from the Salton Sea to supply and maintain a ¼ acre shallow marine habitat pond on recently exposed lakebed (see Appendix 1 and 3). The Project will construct a ¼ acre Salinity Gradient Solar Pond (Appendix 2) adjacent to the habitat pond to receive saturated brine derived from the Salton Seawater distillation and habitat pond water recycling. Evaporators and a condenser from an existing Vertical Tube Evaporator (VTE) distillation pilot plant (Appendix 7) will be installed at the ponds to maintain a salinity gradient that will trap heat from the sun to drive a long term on site thermal distillation process. The pond site distillation plant will maintain both the shallow marine habitat pond and the salinity gradient solar pond with distilled water make-up. Evaporative losses will be controlled to the extent practicable with a film or non-toxic molecular monolayer and made up from Salton Seawater. The Project location on the south shore of the Salton Sea (Appendix 4) was chosen because it is recently exposed playa with excellent proximity to existing habitat, water sources, the electrical grid, and less than ½ mile from a geothermal power plant with an existing desalination test plant (Appendix 5). The VTE Salton Sea desalination test plant is driven by free heat from low pressure geothermal steam. The location is roughly equidistant between the outflow of the New River and the Alamo River on several acres of IID owned playa (Appendix 6). Within the first year, the Project will test available non-toxic molecular monolayer products in evaporation pans, measure seasonal insolation, ambient, and subsurface temperatures at the location, contract a geotechnical evaluation of the local playa, and test methods to clarify and decolorize Salton Sea brine concentrate for the solar pond under existing permits. On completion of new environmental and construction permitting (1 year) the two ponds will be built. The habitat pond can be in operation within 6 months of construction start. The VTE Demonstration Plant now under construction (Appendix 8) will distill Salton Seawater with heat from low pressure geothermal steam to dilute the habitat pond to a target salinity of 35,000 ppm TDS with no accumulation of selenium or other critical contaminants (Appendix 9, 12). Fish and invertebrates currently in the Salton Sea will be introduced to the habitat pond. These can be desert pupfish, or any mix of local fish species. Piscivorous birds including brown and white pelicans already frequent the site and are likely to forage. Stable desert pupfish habitat is a concern. Additional habitat will help stabilize the desert pupfish population at the Salton Sea. The VTE Demonstration Plant will sustain the Marine Habitat Pond with distillate while the Salinity Gradient Solar Pond is being filled with brine (Appendix 10, 12). The Salinity Gradient Solar Pond and integrated distillation plant can be in operation about 1 ½ years after construction start when the solar pond has a gradient established so that it can capture solar energy to drive the distillation plant at the ponds (Appendix 11). At least one year of operation will be needed to evaluate the solar energy, water, and salt balance of the operation in all seasons and observe and record wildlife usage of the habitat pond and any interaction that may or may not occur with the adjacent salinity gradient solar pond. Research Methods The Project will investigate the hypothesis that habitat for critical fish and piscivorous bird species at the Salton Sea can be conserved by creating a microcosm of the near zero outflow Salton Sea aquatic environment in a shallow marine habitat pond that can be sustained over time at a desired salinity by replacing evaporative and seepage losses with distilled water recycled from the Salton Sea. This approach can be far more water efficient than other habitat water supply being considered at the Salton

5 Sea. Water supply to habitat currently planned using the polluted New and Alamo Rivers require a high rate of flushing to prevent evaporative build up of selenium and other toxic contaminants. Distilled water is contaminant free and thus can make up evaporation losses in ponds with little or no flushing. Evaporative Loss Control Investigate the efficacy of available films and molecular monolayer products to reduce evaporative losses by dosing selected products into seawater in an evaporation pan. Measure evaporation rate and temperatures while holding salinity steady with distilled water make-up over time versus a non-dosed control pan. Solar Pond Brine Treatment Develop a protocol for concentrating, clarifying, and decolorizing saturated Salton Sea brine. Concentration has been tested with the VTE Pilot Plant. The brine needs to be clear and a yellow color from organic matter needs to be removed. For clarifying brine, settling and filtration will be tested. Activated charcoal can remove the color from organic matter and will be tested. Insolation Measurement Measure insolation at the project location over four seasons by installing and monitoring a pyranometer at the site. Estimate available solar energy for thermal desalination and possible future electrical generation. Playa Soil Study Drill core samples at the pond location for a geotechnical study of soils under the playa. Install temperature probes and heated fluid loops into the drill holes. Record temperature at various depths under the playa over four seasons. Obtain sub-surface thermal conduction data by injecting hot fluid into a borehole pipe loop and measuring temperature rise in an array of adjacent boreholes. Estimate heat loss from the bottom of a salinity gradient solar pond, evaluate thermal conductivity of soil for geo-cooling, and observe any asymmetric heat flow indicating subsurface water flows. Soft Playa Construction Methods Work with contractors experienced in local dike construction to develop construction methods for heavy equipment on soft playa. Try moveable work platforms, progressive berm fill and compaction, and extra low ground pressure per square inch tires and tread extensions. Habitat Pond Water Treatment Fill habitat with Salton Seawater, dilute to 35,000 ppm TDS with distilled seawater from the existing VTE plant. Measure the shallow marine habitat pond water at key intervals for selenium, salinity, nutrients, and any other constituents that may impact wildlife. Introduce selected invertebrate and fish species to the shallow marine habitat pond and monitor population. These can be desert pupfish, or any mix of species selected by a Project biologist. Develop a system to automatically dose both ponds with a selected molecular monolayer product in response to seasonal evaporation rate changes and high winds or methods to deploy a surface film. Solar Pond Water Treatment Adapt the solar pond water and salt recycling process used in a 1989 Los Banos VTE test to work with Salton Sea source water.

6 Monitoring During Operation Monitor the salinity gradient, thermal profile, evaporative losses, optical clarity, and any leakage of brine from the Salinity Gradient Solar Pond over four seasons of operation. Monitor the Marine Habitat pond for water quality including salinity, selenium, and nutrients. Monitor biological activity in water and sediment, fish population and use by birds. The monitoring program can be a modest expansion of the existing IID monitoring done as part of the QSA mitigation. Develop methods to correct for any imbalance in the desired water quality and biota by adjusting the inflow and outflow rate to the Sea, filtration, or other methods. Identify and correct any negative interaction of the co-located ponds by measuring the clarity and gradient stability of the solar pond, observing wildlife use, and measuring any leakage of heat or brine impacting the habitat pond. Project Schedule The project will be executed over five years including a one year administrative delay to start. Task Name Duration Start Finish Salton Seawater Marine Habitat Demonstration 1307 days Fri 3/1/13 Mon 3/5/18 1. Administration 1307 days Fri 3/1/13 Mon 3/5/18 2. Labor Compliance Program 1252 days Mon 4/1/13 Tue 1/16/18 3. Reporting 934 days Wed 9/25/13 Mon 4/24/17 Final Report Submitted Milestone Mon 4/24/17 Mon 4/24/17 4. Assessment and Evaluation 342 days Fri 2/14/14 Tue 6/9/ Evaporative Loss Control 291 days Fri 2/14/14 Mon 3/30/ Solar Pond Brine Treatment 60 days Mon 6/9/14 Mon 9/1/ Insolation Measurement 332 days Fri 2/28/14 Tue 6/9/ Playa Soil Study 271 days Tue 5/27/14 Tue 6/9/15 Assessment Studies Complete Milestone Tue 6/9/15 Tue 6/9/15 5. Final Design 58 days Wed 6/11/14 Fri 8/29/ Shallow Marine Habit Pond Design 33 days Wed 6/11/14 Fri 7/25/ Salinity Gradient Solar Pond Design 33 days Wed 6/11/14 Fri 7/25/ Pipeline Design Between Existing VTE Plant and Pond Site 13 days Mon 7/28/14 Wed 8/13/ Pond Site Desalination Plant Design 25 days Mon 7/28/14 Fri 8/29/14 Final Design Complete Milestone Fri 8/29/14 Fri 8/29/14 6. Environmental Documentation 145 days Mon 9/1/14 Fri 3/20/15 CEQA Complete Milestone Fri 3/20/15 Fri 3/20/15 7. Permitting 305 days Mon 2/17/14 Fri 4/17/ Extend RWQCB Waiver for VTE Demonstration Project Distillate Return to Salton Sea 133 days Mon 9/22/14 Wed 3/25/ Extend Minor Amendment to Imperial County CUP for VTE Demonstration Plant 45 days Thu 9/25/14 Wed11/26/ California DFG Approval of Fish Screening for Salton Seawater Intake 32 days Thu 10/2/14 Fri 11/14/ Request RWQCB Waiver for Habitat Pond Water Return to Salton Sea (if any) 140 days Mon 10/6/14 Fri 4/17/ Imperial County Public Works Permit for Dirt Road Crossing by Pipeline 143 days Mon 2/17/14 Wed 9/3/ Department of Fish and Game Section 1602 Notification and Permit for Ponds 103 days Mon 10/20/14 Wed 3/11/ U.S. Army Corps of Engineers Section 404 Permit for Ponds 80 days Mon 11/3/14 Fri 2/20/ RWQCB Section 401 Permit for Ponds 80 days Mon 12/1/14 Fri 3/20/ Imperial County Conditional Use Permit for Ponds 75 days Mon 12/29/14 Fri 4/10/ Imperial County Grading Permit for Ponds 43 days Mon 1/19/15 Wed 3/18/ Imperial County Building Permit for Ponds & Desal Plant 43 days Mon 2/2/15 Wed 4/1/ Imperial County Air Pollution Control District Construction Permit for Ponds 45 days Mon 2/16/15 Fri 4/17/ Imperial County Building Permit for Pipeline Between VTE Plant and Salton Sea 43 days Thu 3/6/14 Mon 5/5/14 Permitting Complete Milestone Fri 4/17/15 Fri 4/17/15 8. Construction Contracting 91 days Mon 4/13/15 Mon 8/17/15

7 Construction Contracting Complete Milestone Mon 8/17/15 Mon 8/17/15 9. Construction 699 days Tue 5/13/14 Fri 1/13/ Mobilization and Site Preparation 91 days Tue 7/21/15 Tue 11/24/ Project Construction 454 days Tue 5/13/14 Fri 2/5/ Salinity Gradient Solar Pond Earthworks 33 days Fri 10/16/15 Tue 12/1/ Shallow Marine Habitat Pond Earthworks 18 days Wed 11/25/15 Fri 12/18/ Salinity Gradient Solar Pond Lining 6 days Wed 11/25/15 Wed 12/2/ Salinity Gradient Solar Pond Piping days Wed 10/28/15 Wed 1/6/ Shallow Marine Habitat Pond Piping 25 days Mon 11/30/15 Mon 1/4/ Pipeline from VTE Demo Plant 392 days Tue 5/13/14 Wed11/11/ VTE Distillation Plant Relocation to Ponds 66 days Fri 11/6/15 Fri 2/5/ Performance Testing and Demobilization days Thu 11/12/15 Fri 1/29/16 Physical Construction Complete Milestone Fri 1/29/16 Fri 1/29/16 Performance Testing 245 days Mon 2/8/16 Fri 1/13/ Shakedown Test Pond and VTE Plant Sytems 24 days Mon 2/8/16 Thu 3/10/ Habitat Pond Water Treatment 221 days Fri 3/11/16 Fri 1/13/ Salinity Gradient Solar Pond Water Treatment 218 days Wed 3/16/16 Fri 1/13/ Shut Down VTE Demonstration Plant and Prepare to Move it Off CalEnergy Site 15 days Mon 12/26/16 Fri 1/13/17 Ponds Ready to Operate Milestone Fri 1/13/17 Fri 1/13/ Environmental Compliance/Mitigation/Enhancement 260 days Mon 1/16/17 Fri 1/12/ Maintain Habitat and Solar Pond with Distilled Seawater from VTE Pilot Plant on Solar Heat 260 days Mon 1/16/17 Fri 1/12/ Monitor Salinity Gradient Solar Pond for Optical Clarity Thermal & Gradient Profile and Leakage 260 days Mon 1/16/17 Fri 1/12/ Monitor Habitat Pond for Salinity Selenium Nutrients Fish and Birds 260 days Mon 1/16/17 Fri 1/12/18 Year Long Operation Test Complete Milestone Fri 1/12/18 Fri 1/12/ Construction Adminstration days Wed 8/12/15 Tue 2/2/16