Challenge

The Devlin WWTP in Roselle, IL, needed to expand and improve treatment to meet stringent effluent quality standards.

Solution

Siemens Water Technologies provided three key wastewater treatment technologies during an expansion project in 1988.

• In the preliminary treatment area, a medium bar screen takes out large solids in the influent stream.
• Following primary and secondary treatment, flow proportional V-notch chlorinators provide disinfection, followed by sodium thiosulfate addition for dechlorination (summer operation only).
• Four Hydro-Clear® pulsed bed sand filters by polish effluent to its crystal clear quality before it is released into Spring Brook. The filter cells are situated in concrete tanks and are 9 ft wide by 21.5 ft long.

Results

The systems have all performed reliably since installation as part of a major plant expansion in 1988. In 2003, the Devlin plant scored the highest in effluent quality, maintenance, process control, laboratory practices and public information, and was named the Best Operated Plant among the 168 Group I operations in Illinois. The Devlin Plant had been nominated by the Illinois EPA twice before for the state’s top award.

“We were elated to finally get it this time,” says Lead Operator, Jeff Peto. “They don’t reveal the winner until the last minute at the annual conference of the Illinois Water Pollution Control Operators.”

The Devlin Plant and its sister operation, the Botterman Plant (1.4 MGD), serve the 23,000 residents and businesses of Roselle, located just a few minutes south and west of Chicago’s O’Hare Airport. 

The Devlin team and their technology easily meet requirements of 10 milligrams per liter BOD and 12 mg/l suspended solids. In fact, the average effluent values for 2002 were 2.5 mg/l BOD and just over 3.0 mg/l suspended solids.