MCWD, Ormat continue to wrestle
According to Mammoth Community Water District (MCWD), Ormat, the geothermal power company that operates at the corner of State Highways 395 and 203, could be stirring a giant cocktail of geothermal fluid and domestic drinking water with its operations. The environmental impact report (EIR) for Ormat’s proposed Casa Diablo IV geothermal power plant claims there is an impenetrable barrier that separates the geothermal fluid from the domestic water supply at the proposed site of development. MCWD claims it’s found a hole in that wall that is allowing the liquids to intermingle. Geothermal fluid contamination would destroy Mammoth’s domestic water supply by allowing toxins into the community’s water source.
The Casa Diablo IV project is expected to increase output at Ormat’s geothermal plant from 29 megawatts to 59, enough to power 40,000 homes hourly. The Casa Diablo IV project is not yet in operation but MCWD wants to curtail any damage or water contamination before any mixing occurs.
The US Geological Survey (USGS) began collecting new data in 2015. At that point, the project and EIR had already been approved by the Bureau of Land Management (BLM). The BLM is responsible for managing underground extractions of any kind from public lands, including those facilitated by mining and geothermal power operations.
In 2017, the BLM also drafted a Groundwater Monitoring and Response Plan, which provided the final approval for Ormat to move forward with the Casa Diablo IV project. The plan spells out what monitoring is needed and sets thresholds for Ormat for extraction and injection of geothermal fluids.
Following the USGS’s collection of new data in 2015, MCWD hired Wildermuth Environmental, Inc. to compile and analyze the data. Wildermuth Environmental, Inc. published its findings in a new report this month.
In a prepared statement issued in January, Ormat stated that, in continuing to challenge Casa Diablo IV, MCWD is continuing a media campaign for a battle it’s already lost at great expense to its customers because the BLM has already approved the project.
Ormat still contends there is no connectivity between the geothermal fluid and Mammoth’s drinking water. It also claims the new data offered by the USGS has not been peer reviewed and so has little if any merit.
The data collected by USGS in 2015 includes chemical analysis of water samples from monitoring wells near Ormat’s existing geothermal wells. The USGS National Water Quality Laboratory in Denver tested the samples.
“Do we want to wait around before we take a call to action or do we take action now?” Pat Hayes, MCWD Executive Director asked. “I think we’re in the second category.”
Hayes stated in a press release on March 16 that the impacts of intermingling are preventable. He is recommending that Ormat take three steps to curtail any potential damage to the Town’s water supply. First, he asks that Ormat install water monitoring wells as part of the Casa Diablo IV project as an early warning system that would detect any commingling of the geothermal fluids with the Town’s groundwater. Two, he asks that Ormat be transparent by sharing all well and operations data it collects. Three, he asks that Ormat adopt and enforce an adequate Groundwater Monitoring and Response Plan.
Paul Thomsen, Executive Director of Ormat told The Sheet on March 21 that the Wildermuth report is currently being review by Ormat’s staff.
He added that he was a little confused about why Hayes’ requests were aimed at Ormat, as the BLM is the agency responsible for requiring the construction of a new well and any transparency measures involving Ormat’s monitoring and data collection. It would also be responsible for drafting a new Groundwater Monitoring and Response Plan.
Thomsen addressed MCWD’s three requests with responses that all led to Ormat being in compliance with the Response Plan already put in place by the BLM. The Response Plan requires that Ormat drill and construct monitoring wells, and be transparent with information from those monitoring wells to be published each quarter.
BLM Geologist Mark Spendel told The Sheet that the agency is currently reviewing the Wildermuth report.
If the BLM decides to include a new monitoring well in the Response Plan, Hayes said Ormat would likely pay for the well.