Mammoth Community Water District officials say that the proposed Casa Diablo Geothermal plant expansion could harm both groundwater and surface water resources used to serve the community of Mammoth Lakes.
Casa Diablo Geothermal officials have gone through the environmental investigation of their expansion plans and Mammoth’s Water District has responded. In a press release, the Water District says the geothermal expansion project proposes the development of 16 production and reinjection wells along with a “significant increase in geothermal fluid pumping.” The release also says that several of the proposed new wells are within two miles of the District’s groundwater production wells.
Mammoth Water officials hired two specialists to help in the review of Casa Diablo’s plans. District officials say that pumping or well reinjection could decrease aquifer recharge or alter water quality in the aquifers. There are also concerns about increased pumping by Casa Diablo decreasing flows in Mammoth Creek.
The supply of water to Mammoth comes from both surface water, recycled water and groundwater. According to Mammoth officials, the Draft Environmental Document on Casa Diablo’s proposed geothermal expansion project says there are no significant impacts to the Water District’s operations. According to the District press release, the Casa Diablo document “does not provide sufficient information to support these conclusions.” The Water District’s specialists identified “significant information gaps.”
More information is available on the Mammoth Community Water District website at www.mcwd.dst.ca.us.