Irrigation customers who use much of the reclaimed water from the New Smyrna Beach (Fla.) water reclamation facility plant haven’t noticed a difference. Commercial irrigation storage ponds are still full, though it takes longer to fill them.
But the plant, owned by the Utilities Commission, City of New Smyrna Beach, has made substantial operational changes that are conserving energy and holding down electricity costs. By adjusting and optimizing pressure in the reclaimed water distribution system, the plant staff is saving about $140,000 a year. Similar changes at the drinking water plant next door are saving $100,000 a year while also reducing use from 199 gallons a day per connection to 195 with virtually no complaints.
Saving the resource
Built in 1998, the 7-mgd advanced treatment plant creates high-quality effluent, most of it reclaimed for irrigation for homes, golf courses, and other large commercial customers. “The water resource is very precious, especially in Florida, where there is a limited amount of freshwater and we’re surrounded by saltwater,” says Dave Hoover, director of the Water Resources Department.
The plant is allowed to discharge up to 30 percent of its treated water into the Indian River. Over the last three years, an average of 85 percent of the wastewater coming to the plant has been reclaimed. That number reached 90 percent over the last year. “We’re real excited about it,” says Hoover. “A lot of the investment our utility and ratepayers have made in irrigation piping and developing an adequate customer base has paid off,” Hoover says.
Water reclamation reduces the amount of drinking water used for irrigation and keeps more water in the aquifer. The ecological importance of that is always on Hoover’s mind, but recently his thoughts have been on system pressure. Less pressure in the system means less power demand from the plant.
Hoover got the idea for optimizing pressures from a local utility commercial. “The commercial said that by using two settings on your thermostat — one for when you’re at home and one for when you are away — you could save as much as 20 percent off your energy bill every month,” he recalls. “Another commercial said that if you reset your cruise control to 65 instead of 75, you could save 20 percent on your fuel cost.”
The wastewater plant had always operated with a system pressure of 75 psi. “I kept looking at that, and those commercials kept coming back to me,” Hoover recalls. “I became convinced that we didn’t need to put out 75 psi.” His goal was to use the many variable-speed drives (Yaskawa Electric America) in the plant to respond to demand on the system, rather than setting them for peak demand at all times.
