Desert Renewable Energy Storage Project Raises Water Issues

By Published On: April 30, 2010

With energy storage gaining new impetus as California utilities reach for higher levels of intermittent renewable energy, a Palm Desert-based company is advancing a 1,300 MW pumped storage project in the eastern Riverside County desert. Eagle Crest Energy plans to build the project at the site of an old Kaiser Steel mine near Joshua Tree National Park. It is an area devoid of surface water, averaging 3 inches of rain a year. The company would fill two mine pits to create reservoirs with water pumped from the ancient Chuckwalla Valley aquifer to the east. Known as the Eagle Mountain Pumped Storage Hydroelectric Project, the facility would interconnect 13 miles to the west with Southern California Edison’s system. It would use excess wind and solar power at times when demand for energy is slack to pump water from the lower to the upper reservoir. When demand for power is high, it would let the water run down through turbines to make power, generating about 70 to 80 percent as much energy as it uses to pump the water uphill. In essence, it would be a giant wet battery for storing energy from renewable power in the area. Eagle Crest, which applied for a Federal Energy Regulatory Commission license in 2008, plans to issue a draft environmental impact report in the next few months, according to its counsel, Donald Clarke. The document likely may become a lightening rod for opposition due to concerns about how the project, plus a number of nearby solar energy projects that also would need water, would affect the Chuckwalla Basin aquifer. The project would result in overdraft of the aquifer, according to Curt Sauer, Joshua Tree National Park superintendent. The National Park Service notes that the basin recharges at the rate of about 10,600 acre-feet a year, meaning that the pumped storage plant, as well as the solar plants in the area, would effectively begin to deplete the aquifer. The pumped storage plant would withdraw more than 8,000 acre-feet a year of water to fill the reservoir for three years. Another 2,400 acre-feet would be pumped from the ground annually to make up for evaporation and seepage from the reservoirs on an ongoing basis, according to Eagle Crest documents on file with the Federal Energy Regulatory Commission and data from other public agencies. (An acre-foot is 325,851 gallons. Typically, California families consume about half an acre-foot a year, but that varies by climate and the size of one’s lawn.) Eagle Mountain is one of many energy projects looking to withdraw water from the Chuckwalla Basin aquifer, including the Genesis Solar Project. Genesis plans to pump more than 1,600 acre feet a year. There are seven other solar facilities planned in the Chuckwalla Basin that are in line for the area’s water. A new landfill, also planned at Eagle Mountain, would tap the groundwater too. After construction and start up, the Energy Commission estimates that all of the projects would use more than 3,700 acre-feet of water from the aquifer each year. Existing local water use--while sustainable--is already near the average recharge level. It stands at almost 10,400 acre feet, according to the California Energy Commission. As a result, some area residents fear that lowering the water table, which lies just feet below the surface in low elevation areas, will kill local vegetation and turn the basin into a dustbowl. The CEC notes in its staff assessment for the Genesis plant that lowering the water table could kill mesquites and other plants. The Energy Commission document also warns that overdraft of the reservoir could cause subsidence and interfere with the operation of existing wells. Farms, a prison, and at least one town rely on the aquifer for their water. Donna Charpied, Citizens for the Chuckwalla Valley executive director, warns that if the pumped storage project ultimately is approved “it will deplete the Chuckwalla Valley’s aquifer.” Approving the other solar energy projects too will accelerate that depletion, she contends, qualifying the development of the area for renewable energy as “a case of environmental justice.” Joshua Tree National Park superintendent Sauer also is worried that if Eagle Crest cannot successfully prevent seepage from its operation, it will contaminate groundwater with acid mine drainage, the legacy of decades of mining operations at the site. The giant Metropolitan Water District is concerned about potential effects on its nearby Colorado River Aqueduct, which supplies water to the Southern California megalopolis. While the district has raised several issues, chief among them is that the operation of the pumped storage facility could cause subsidence that would damage its aqueduct, according to district senior deputy general counsel Peter vonHaam. In filings with FERC, Eagle Crest acknowledges its facility could affect the water table. The company told federal regulators it plans to monitor groundwater in the Chuckwalla Basin and mitigate any significant drop in the water table. Near the actual facility, it plans to drill a series of wells to recover seeping water, plus line various areas of the pits that are particularly porous to prevent a localized buildup of water from damaging the aqueduct. The Los Angeles County Sanitation District is worried the energy facility would conflict with its plan to use another one of the mine pits at the site as a landfill for solid waste. The county sanitation agency thinks tunnels to convey water from the upper reservoir to the lower reservoir under the pit slated for waste disposal could cause the landfill’s clay liner to break apart and result in groundwater contamination, according to Alexander Shipman, attorney for the agency. Under a complicated deal that took more than a decade to negotiate and permit, the waste agency has the rights to buy the pit from Kaiser to bury up to 20,000 tons of waste hauled by rail each day from Los Angeles County, where local landfall space is short.

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