Neutrally buoyant produce labels and other floating bits of plastic were passing through the Dublin San Ramon (Calif.) Services District Recycled Water Treatment Facility and entering the distribution system, plugging meters, irrigation strainers and sprinkler heads.
The facility had continuous-backwash upflow sand filters that kept the plastics suspended, allowing them to pass out with the effluent. Judy Zavadil, district senior civil engineer, could not locate another facility with a similar problem. “We had to find our own cure,” she says.
After evaluating bar and drum screens and step and articulating rake screens, the district considered and decided on a band screen. Many
