City will replace disinfection unit at sewage plant
Written by Jane Stebbins, Pilot staff writer   
May 07, 2013 08:14 pm

The Brookings city council has approved the replacement of a ultraviolet light disinfection unit at the Wastewater Treatment Plant, officials there announced Tuesday.

Typically, sewage is processed into wastewater at the plant, and that effluent is discharged into the ocean. The final stage of treating the wastewater is running it through the UV light unit.

“It’s a complex mechanical process responsible for the final treatment of wastewater effluent and necessary for state and federal regulatory compliance before ocean discharge,” said Public Works Director Loree Pryce. “The wastewater enters the UV process and confronts a series of UV lights that eliminate microbes, including waterborne pathogens.”

The project involves replacing the UV system control panel at a cost of $67,000.  

“The control panel is responsible for adjusting the light intensity based on the flows entering the process,” Pryce said.

 “The flows fluctuate constantly, depending on the time of day and discharges received by the treatment plant.”

Pryce said the control panel was no longer functioning reliably and that the system was being monitored manually.

“”Running the system on manual bypass mode results in higher electric costs and puts the city at risk by not having the system monitored 24 hours a day,” Pryce said. 

The current control panel was installed in 2001; the expected life of such a control panel exposed to a corrosive oceanfront environment is about 10 years.