HUALAPAI VALLEY SOLAR an effluent-supported solar project that ...

HUALAPAI VALLEY SOLARan effluent-supported solar projectthat never happenedWilliam R. VictorPrincipal / Hydrogeologist1

Project Overview Hualapai Valley Solar (HVS), subsidiary ofMohave Sun Power 340 MW (largest solar project planned then) Selected proven utility-scale technologies 2008-2009:• Public hearings and open houses• Selected wet-cooled CSP with solar troughs andmolten salt thermal storage• Utilities identified to purchase energy generated• Preliminary design and DOE funding application6

Project Overview (continued) 2010:• Permitting• Effluent source identified• Key ACC permit process ended October 2010 Project infeasible as approved by ACC Deadlines not met for DOE funding Project died7

Permits and Authorizations EIS under NEPA for transmission line Air Permit from ADEQ Comply with all regulations of ADWR Certificate of Environmental Compliance(CEC) from ACC Amendment to Mohave County GeneralPlan (county supported project) APP from the ADEQ8

Environmental Aspects Baseline studies identified no fatal flaws for:Air Quality Health, Safety, and NoiseBiologyRecreationCulturalSocioeconomicsGeology and Soils Visual ResourcesLand Use Water Resources Water resources was a public concern voiced by a smallgroup of local citizens9

Socioeconomic Benefits 1,500 jobs over 2.5-3 year construction period 100+ full-time jobs for plant operation Additional benefits:• Goods and services purchased for the Project• Taxes generated by employment• Property taxes• Other taxes paid to state/local governments10

HVS Natural Water Supply Groundwater stored in thick basin-fill alluvial deposits Must be treated to high purity, generated brine would beevaporated in onsite surface impoundments Average raw water demand = 2,400 AF/yr (1,500 gpm) Projected life of solar plant = 30 yrs Total groundwater use over time = 72,000 AF / 30 yrs Groundwater recharge/discharge and storage in basin• Natural Recharge = Discharge = 3,800 AF/yr• Storage above depth of 1,200 feet = 15.8 million AF(Half of this occurs in Red Lake sub-basin)11

HVS Effluent Supply Effluent from City of Kingman Hilltop WWTP~ 20 miles away WWTP produces about 1,800 AF/yr or ~75% oftotal HVS water demand No current competition for effluent 25-35 mile pipeline required to deliver water Mayor and City management supported plan12

M&A Model Development MODFLOW and Groundwater Vistas Characterized hydrogeologic conditions• Compiled all available hydrologic and geologic data• Data for more than 800 wells• Geophysical data (gravity & borehole logs) ADWR integral to model development and vetting• Hydrology reviewed over several months with muchinteraction and resolution with M&A on key model inputs• 2007 approval• Analysis of Adequate Water Supply issued for 70,000AF/yr groundwater for 5 residential developments13

Location MapSite location and wellsN-NW trending structural basin66 mi x 18 mi (~1,200 sq. mi.)3 sub-basins:Kingman sub-basin (south)Red Lake sub-basinGregg sub-basin (north)14

2005-2006Water LevelsGood calibration to WLs Steady-state 1965-1970 Transient model 1971-2005 Predictive model 2006-2042Groundwater divideSurface water divideGroundwater flows north3,800 AF/yr outflow to lakeRecharge simulated atmountain fronts (70%) andmajor washes (30%)15

Geologic FeaturesBasin boundariesSite locationDepth to bedrock contours3 sub-basinsBuried salt depositsAquifer boundaryLines of sectionGroundwater in storage27.7 million AF total (abovesalt in middle sub-basin)15.8 million AF abovedepth of 1,200 feet16

Hydrogeologic Section A – A Water table 3 sub-basins Salt deposits Well data17

Stable Water Levels Since 1950s18

HVS-only in 2042Pumping simulated: HVS at 3,000 AF/yr Kingman 3% per year Domestic = 34 AF/yr OCD = 9,763 AF/yr Mardian Ranch & RhodesHomes 50-yr build outstarts in 2012 (50,459 AF/yr in 2042) Total (90,884 AF/yr) morethan 3 times thatestimated by County PlanMaximum drawdown at HVSsite 63 ftRapidly diminishing withdistance

HVS-only in 2017(first 5 years)Complies with stringent wellimpact criteria of AMAs forexisting wells

Water Resource FindingsCurrent water use is a minute fraction of groundwater in storageProjected drawdown met AMA criteria for well impacts (not an AMA)After 30 years, small projected impact of HVS pumping;

ACC Process January 2010: Power Plant & Trans. Line Siting Comm.• 10 to 0 vote in favor of project• Two local citizens did not comply with requirements asinterveners, but were allowed to speak at length and askcommittee members questions to ask HVS April 2010: ACC granted a conditional CEC to HVS• CEC subjected to an immediate stay to reopen the matter• Requests for intervention granted to 2 local citizens andMohave County June 2010: ACC Evidentiary Hearing in Kingman July 2010: HVS filed application to lift stay on CEC October 2010: ACC Open Meeting• Chairman added condition to CEC requiring HVS to use nogroundwater despite the minimal impacts testimony• Chairmans condition passed by a 3 to 2 vote• Conditioned CEC approved by a 4 to 1 vote22

THE END23

ADWR Report,September 2009Gravity data shows newbedrock (BR) surfacePreliminary ADWR dataused in model in 2007Color coded Blue = model BRdeeper Red = ADWR BRdeeperSimilar in Red Lake subbasin,which most affectsmodel results for HVSpumpingEffect of differences notsubstantial, especially inRed Lake sub-basin (~5%)25