Mammoth Lakes, CA March 15, 2018 – Findings from a new groundwater quality investigation confirm that Ormat Technologies’ existing geothermal operation and proposed expansion project – known as Casa Diablo IV (CD-IV) – present an unnecessary, existential threat to the Mammoth Lakes community’s main and most reliable public water supply.

“We are charged with protecting our region’s precious water supply and have repeatedly asked Ormat to partner with us to ensure our water supply is not impacted by Ormat’s geothermal pumping,” said Pat Hayes, General Manager of Mammoth Community Water District (MCWD). “Despite sound science and expert recommendations, Ormat continues to place the community’s groundwater at unnecessary risk. If the company were truly committed to clean energy and sustainable practices, it would implement the necessary safeguards to preserve and protect our community’s groundwater.”

MCWD commissioned Wildermuth Environmental, Inc., a respected, highly-specialized water resources consulting firm, to analyze groundwater monitoring data collected by the experts at the United States Geological Survey – the sole science agency for the U.S. Department of the Interior. Wildermuth’s scientific analysis and conclusions demonstrate clear evidence that geothermal fluids are present in Mammoth’s groundwater basin, confirming:

  1. Fractured rock allows water, heat and other elements to travel between Mammoth’s groundwater basin and Ormat’s geothermal reservoir.
  2. The conclusion of no impacts to Mammoth’s groundwater basin in the environmental review of Ormat’s geothermal expansion project was based on a fundamentally flawed assumption that an impermeable barrier prevents Ormat’s geothermal reservoir from mixing with the Mammoth community’s groundwater.

The connection between Mammoth’s groundwater and Ormat’s geothermal reservoir places the community’s drinking water at risk of contamination or depletion, and the threat is imminent. Ormat’s CD-IV project will expand geothermal pumping closer to Mammoth’s groundwater wells, placing new stresses on the region’s complex, interconnected hydrologic system. Without necessary safeguards, increased geothermal pumping from Ormat’s CD-IV project could cause:

  • Irreversible groundwater contamination – Continued geothermal intrusion could cause significant harm to water quality – even if geothermal pumping is stopped. In particular, once arsenic levels reach a certain threshold, MCWD’s existing arsenic removal treatment technologies cannot achieve potable drinking water standards.
  • Depletion of the community water supply – Mammoth’s groundwater could leak into the underlying geothermal reservoir as a result of changes in pressure.

Robust safeguards are needed to protect the water supply. Even a small loss of supplies could be cumulatively catastrophic, forcing the Mammoth community to find an alternative water supply – an expensive and uncertain process, requiring years of planning and environmental review. However, the potentially devastating impacts of Ormat’s geothermal pumping are preventable. MCWD does not oppose Ormat’s geothermal project, but the District is calling on Ormat and regulators to do their part to protect the community’s water supply through three simple steps:

  1. Be responsible – don’t put our groundwater at unnecessary risk. Install the necessary monitoring well to collect important data regarding the extent of the threat and ensure an early warning system to avoid potential groundwater degradation.
  2. Be a partner in protecting our water supply. Share timely, complete and transparent well monitoring and geothermal operations data with MCWD, federal and state regulators, community members, and elected officials.
  3. Establish a plan with checks and balances. Adopt and enforce an adequate Groundwater Monitoring and Response Plan that clearly defines monitoring thresholds and requires, if necessary, feasible actions for providing an alternative water supply for Mammoth Lakes.

“Mammoth’s tourism industry is the economic heart of our region. My colleagues and I serve the families, employees and business owners, large and small, who are keeping the beat – and we simply cannot allow Ormat to leave them high and dry,” said Mammoth Community Water District Board President Thomas Smith. “While I am a strong supporter of bringing clean energy to our state, energy cannot be considered clean if it comes at of the cost of clean water supplies that serve our communities.”

Ormat is being consciously negligent with Mammoth’s drinking water. The foreign-owned, publicly-traded geothermal giant is the largest company of its kind in the world with a current market value of $3.25 billion. It has the financial wherewithal to invest in adequate safeguards to protect Mammoth’s water supply, but has repeatedly refused to do so. It’s unclear why Ormat is choosing to put Mammoth’s precious groundwater supply at risk, when solutions are readily available to protect the water and community.

The new data analyzed in the Wildermuth report provides clear evidence of a connection between Mammoth’s groundwater and Ormat’s geothermal reservoir, disproving the fundamental assumption of complete separation used as the basis for the project’s environmental review and conclusions – an assumption made by Ormat without using transparent, scientific evidence. Great Basin Unified Air Pollution Control District needs to reopen the environmental review process – the people of Mammoth Lakes deserve a substantive, thorough review of the project’s potentially significant impacts on Mammoth’s water supply – before it’s too late.

“There is a right way and a wrong way to develop clean energy sources. When projects pose a significant negative impact to our environment, the California Environmental Quality Act requires those impacts must be disclosed and mitigated where feasible. The solution is simple – if Ormat is unwilling to voluntarily do the right thing, then our regulators and elected leaders must step up to the plate,” added Hayes.

For more information and to read the full report, please visit: