Federal and state authorities are giving a tentative green light to a massive $1.4 billion energy storage project planned for the Riverside County desert area despite local concerns about water supply. The Federal Energy Regulatory Commission staff Dec. 23 recommended a license for the 1,300 MW Eagle Crest Energy pumped storage project slated for abandoned surface mine pits on Eagle Mountain near the town of Desert Center. In a draft environmental impact statement, however, FERC staff called for additional mitigation measures beyond those proposed by the company. Meanwhile, the state’s lead agency in permitting expects later this year to recommend approval of the project. It would store intermittent wind and solar energy, as well as fossil-fired and nuclear power, to smooth out supply and demand for electricity. Scientists and engineers at the State Water Resources Control Board believe concerns about the project’s potential impacts on the water table and water quality can be adequately addressed with careful engineering, according to Paul Murphey, an agency geologist who has been evaluating Eagle Crest’s proposal. He said final state environmental approval could come as early as this spring. Based on initial review, Eagle Crest president Steve Lowe said he has no concerns about the additional mitigation measures outlined by FERC. He said the project--which would pump water to a high reservoir when there is excess power production and release it to a downhill reservoir through turbines that create electricity when power is needed-- can provide a “buffer” to ensure the reliability of the grid as the state reaches toward its goal of 33 percent renewable energy by 2020. Lowe told Current that if Eagle Crest can obtain all the necessary government approvals--including permits from the State Water Resources Control Board and FERC--it could start construction as early as 2013 and begin operating the plant by 2017. Meanwhile, a citizen’s group remains opposed to the plant. It is concerned it will drain the water table in the surrounding Chuckwalla Valley, plus degrade the quality of the desert area’s groundwater supply, said Donna Charpied, Citizens for the Chuckwalla Valley executive director. At issue is that in order to start the hydroelectric project Eagle Crest would need to fill the abandoned mine pits it plans to use as reservoirs with 24,200 acre feet of water pumped from wells. Then it would have to regularly top off the facility to replace water lost through both evaporation on the surface and seepage from the bottom of the pits through the soil. An added problem is that evaporation would concentrate salts in the reservoir, which would pose the risk that seepage back into the water table would contaminate the groundwater over time. To prevent contamination, one mitigation measure FERC outlined calls for Eagle Crest to filter reservoir water through reverse osmosis units to remove salt. The agencies also are calling for extensive monitoring of both groundwater levels and groundwater quality to prevent impacts on existing water users and facility operators in the valley. Charpied said that pumping water for the project--along with pumping water to supply a number of solar energy projects recently approved in the area--could cause the water table to fall so much that wells supplying communities, residents, and farms in the area will run dry. She said projections that rain can replenish the water table after the project’s initial draw down are based on “voodoo arithmetic.” “This is a desert,” she said, “and our groundwater is ancient.” Consequently, Charpied predicted area residents ultimately would sue to block the project if government regulators approve it. The powerful Metropolitan Water District initially worried that pumping groundwater could cause land subsidence in the area, undermining its Colorado River Aqueduct, one of the main supplies for water in the giant Southern California metropolitan area. However, MWD power resources manager Jon Lambeck said that proposed mitigation measures by Eagle Crest and the state have allayed its concerns. State geologist Murphey concurred that the water levels can be managed to accommodate existing water users, prevent subsidence, and allow the new energy storage project to go forward. Lowe pointed out that the alternative to the project would be to build fossil-fueled peaker plants to even out the intermittent production of renewable power on the grid as the state increases reliance on wind and solar power. This would increase emissions of greenhouse gases and other pollutants, he said. Eagle Crest’s pumped storage facility would consist of a 191-acre upper reservoir and a 163-acre lower reservoir, both of which used to be iron mining pits. Between the pits the company plans to construct an underground powerhouse with four reversible pump-turbine units each capable of generating 325 MW of power. Water would be brought in from surrounding wells. Power to and from the facility would flow over a new 13.5 mile long transmission line to interconnect with Southern California Edison’s planned Devers-Palo Verde Number 2 500-kV transmission line. The project would occupy both federal land managed by the Bureau of Land Management and property now owned by Kaiser Ventures, which formerly mined the area. Eagle Crest estimates it will cost $1.4 billion to build the project. FERC estimates the project will generate 4.3 million MWh/year of electricity at a cost of about $31/MWh.