Water Usage at Sunflower Electric's Holcomb, Kansas, Coal Plants
Prepared by the Kansas Chapter, Sierra Club 9-04-06
Sunflower Electric has indicated they will need about 8000 acre-ft per year of water to operate each of their three proposed new 660 MW boilers. This will be needed to operate water cooling towers. These work by evaporating to the atmosphere water that is used to condense steam after it runs through turbines to produce electricity. These quantities are very consistent with what the existing 360 MW Holcomb 1 power plant has been using since start up in 1983. So the total water rights required for all four boilers will be about 30,000 acre-ft. At an average annual capacity factor of 85%, total use will be about 8 billion gallons of water per year.
As is the case with Holcomb 1, this water will be pumped out of the Ogallala aquifer. We reviewed well water level measurements maintained by the Kansas Geological Survey for the existing water wells used by Sunflower Electric to operate Holcomb 1. The water table before initial operation of Holcomb 1 averaged 87 feet. The level in 2003 and 2004 was about 180 feet below the surface. Thus the water table had declined 93 feet since the initial operation of Holcomb 1 in 1983.
Some of this decline will reflect the cone of depression caused when large quantities are being pumped out of the wells. Measurements prior to 1983 would have reflected water levels after irrigation season when water levels had time to return to equilibrium. On the other hand such cones of depression will be a permanent condition because the coal plants are operated year round. The Groundwater Management District has stated that the broad area around the Holcomb plant has already been subject to significant declines in water table.
The power plants and supporting water pumps at Holcomb will be operating at full capacity in the summer at the same time that irrigation needs in the area are greatest. Sunflower Electric usually shuts down their plant in April for maintenance when electricity demand is very low. In years when rainfall is good in western Kansas farmers can cut back on irrigation use. However, Sunflower Electric will need to pump continuously from the aquifer for 50 to 75 years to protect their very large investment.
We conclude that Sunflower Electric should be required to perform a full scale hydrological study of the area to demonstrate whether or not there will be harm to the surrounding community. They should also explain why they do not use air cooled heat exchangers instead of evaporative cooling towers. Air cooled heat exchangers work like a car radiator and cause no water loss.