Most people outside the utility industry think of getting a golden tan from a plastic bed when they think of ultraviolet (UV) rays. But many of us at GUC think of UV in a different "light."

GUC's Wastewater Treatment Plant (WWTP) uses UV light as one of the final steps to disinfect water prior to discharging it back into the Tar River. The plant, which treats more than 11 million gallons of wastewater per day, has two UV units that were installed in 1994 and 1996. The average useful life of a UV system is about 20 years, so these two units have recently undergone what's due, a replacement.

The project involved replacing a medium pressure system with an energy efficient, low pressure, high intensity system. Bottom line is that the new UV system as a whole (water flow changes, new equipment, etc.) will reduce the annual power consumption of the equipment by more than 70%. That results in an annual operating and maintenance savings of over $100,000.

Construction began last fall at the plant and was done in phases. Replacing such a vital part of the wastewater treatment process involved careful and strategic planning.

"We replaced one UV unit at a time," said Jason Manning, WWTP Superintendent. "The best time to shut down a UV channel is the driest part of the year, which is outside of hurricane season."

Construction involved building a new control panel and a canopy over the panel; replacing two UV channels (controls water flow); and the installation of the two new units. The new system was put back into service before the start of this year's hurricane season, which started June 1st.