The Oregon Institute of Technology (OIT) campus has used geothermal energy for heating since 1964, and cooling since 1980. Three hot water wells drilled during the original campus construction range in depth from 1,300 to 1,800 ft. These wells supply all the heating needs of the 11 building 600,000 sq. ft. campus. The combined capacity of the well pumps is about 800 gpm of 192F water. All are equipped with variable speed drives to modulate flow to campus needs. The actual flow rate for heating is dependent upon outside temperature. Swimming pool and domestic hot water heating impose a small, but relatively constant, year-round flow requirement