OFF-PEAK PUMPING OF POTABLE WATER
REFLECTS SUBSTANTIAL SAVINGS

By RONALD G. NAYLOR, P.E., Director of Public Works

Seven months (as of December 1988) of experience with off-peak pumping of potable water in DeKalb, Ill., shows promise of meeting an expected $150,000 reduction in annual electrical costs for the city's water division.

Electric bills averaged $248,881 in the 5-year period of June 30, 1984 through June 30, 1988. Projecting from a 7-month average of $8,550, the 1989 bill is expected to total $102,600. That is a savings of $146,281 or 59.8 percent of the gross electric bill. It is a savings of 64.6 percent on the potable water pumping portion of the bill. Utilization of the 6T Rate offered by Commonwealth Edison for municipal off-peak pumping has dropped the net kilowatt hour rate from 7.787¢ to 2.756¢.

Off-peak pumping is possible because of a two-year building program. This includes construction of two elevated storage tanks with two million gallon capacities each, two 1,200 gpm wells, about six miles of new water mains, and the installation of an automated and computerized control system.

DeKalb's updated water system serves 33,000 citizens, Northern Illinois University, the second largest university in the state, and a growing business/industry contingency. Daily consumption averages 4.2 million gallons.

The project was financed through a 20-year, $5.3 million general obligation bond issue and a user rate increase. The rate increase was imminent even if the improvements had not been made.

The system is expected to be adequate at least until 1995 unless unforeseen demands arise. •

Page 18 / Illinois Municipal Review / March 1989