Hydrogeologic Support for a Solar Power Plant
M&A demonstrates that there is sufficient groundwater available to support a renewable energy project without significantly impacting nearby users.
- Clients: Mohave Sun Power
- Time frame: 2009–2011
- Location: Mohave County, Arizona
The proposed 340-MW Hualapai Valley Solar (HVS) project was located in the northwest part of Arizona, near Kingman. As one of the largest "wet-cooled" concentrating solar plants in the state, HVS was expected to need about 2,400 to 3,000 AF/yr of water for its operations. Although HVS initially planned to use groundwater, it evaluated the feasibility of incorporating treated effluent and other renewable water supplies.
M&A provided hydrogeologic expertise, which included a comprehensive groundwater flow model, to support the permitting and development of this facility. The use of groundwater resources was identified as the highest concern of regulatory agencies and a vocal group of local citizens.
- Analyzed all available groundwater quality data to assess compatibility with the facility's needs
- Sited and constructed four production wells
- Worked with the BLM and the Western Area Power Administration to prepare the water resources analysis for an EIS that addresses the transmission line route
- Developed a comprehensive groundwater flow model to assess impacts to aquifers and nearby users in the project vicinity
- Presented results of its investigation at hearings of both the MCPZC and the BOS
- Provided 2 days of testimony to the Arizona Power Plant and Transmission Line Siting Committee regarding HVS' application for a Certificate of Environmental Compliance
M&A's model demonstrated that the proposed groundwater use would have an insignificant impact on the more than 15 million AF that is stored in the basin above a depth of 1,200 feet. The model also predicted that water levels would change by less than 1 foot in the surrounding populated areas if HVS pumps for 30 years and uses only groundwater for cooling. Because the project lies outside of an AMA, it is not subject to ADWR's well-impact restrictions. Nonetheless, the modeling projected that the drawdown in off-site wells would meet ADWR's stringent drawdown criteria. One notable finding was the fact that HVS' proposed groundwater use was actually about half of the use planned under a previous residential development scenario for the site.
The project received unanimous approval to proceed from the Mohave County Planning and Zoning Commission (MCPZC) and the Board of Supervisors (BOS). In addition, the application for a Certificate of Environmental Compliance was approved unanimously.
However, a setback occurred in late 2010. After extensive presentation of project plans by M&A and others, the Arizona Corporation Commission (ACC) concluded that HVS had to rely on renewable water sources in order to proceed.