KINGMAN - Hualapai Valley Solar continues to work on an agreement with the city of Kingman to purchase treated wastewater from the city's Hilltop Wastewater Treatment Plant.
The water would be used to cool the turbines and wash mirrors at Hualapai Solar's 340-megawatt concentrated solar plant proposed to be built near Red Lake, about 27 miles north of Kingman.
Representatives from Hualapai Solar have said several times in the past that they hoped the agreement would be finished by the end of July.
Kingman City Manager Jack Kramer said there is not one particular issue that is slowing the negotiations. There are several important issues under consideration such as how many years the city will sell the effluent to the plant and how much effluent will be sold, he said.
Currently, the city and Hualapai Solar are looking at a 10-year contract for 900,000 gallons of A+ effluent a day, Kramer said. The contract could be renewed every five years after 2020.
City Council has already determined that the effluent will be sold at 64 cents per thousand gallons, he said.
"We're getting really close, but it's not ready to go before Council yet," Kramer said.
Hualapai Solar would also have to provide a means of transporting the effluent from the city's wastewater plant to the solar plant, Kramer said. Hualapai Solar has already pledged to build a pipeline.
The exact cost and length of the pipeline depends on its route. Hualapai Solar Project Manager Greg Bartlett has said the company is currently negotiating rights of way.
Water, especially the use of groundwater, has been a significant issue in the development of the plant. According to the city, Kingman's Hilltop Wastewater plant can produce around 1,600 acre-feet of water a year.
The plant is expected to produce around 2,300 acre-feet a year by 2016. Until then, Hualapai Solar's plant will have to draw groundwater to meet its cooling needs.
Mohave County residents Denise Bensusan and Susan Bayer have raised the water issue several times before the Mohave County Planning and Zoning Commission, the County Board of Supervisors and as interveners during hearings before the Arizona Corporation Commission Line Siting Committee and the commission itself for Hualapai Solar's certificate of environmental compatibility.
Both women believe that the Hualapai Valley aquifer, which the plant would draw groundwater from, is in depletion and the solar plant would drain the aquifer to the point that it would damage the surrounding ecosystem and dry up local wells.
They are also skeptical of Hualapai Solar's claims to build a pipeline and use effluent. Both women want the ACC to compel Hualapai Solar to use only effluent to cool the plant or make the plant use dry-cooling or hybrid-cooling technology instead of wet-cooling technology.
In return, Hualapai Solar has said that the company has studies that prove that there is more than enough water in the aquifer for the plant and the surrounding community.
The company has also argued that using dry- or hybrid-cooling technology would not be feasible or efficient. The technology would increase the cost of power produced by the plant because the plant would have to use more energy to cool its turbines, according to Hualapai Solar documents submitted to the ACC.
It would have to sell its power at a higher cost in order to cover the extra usage of power, which would put the plant at a disadvantage in the power market, the documents state.
The ACC has scheduled a hearing on Hualapai Solar's certificate of environmental compatibility for Sept. 22.