Wastewater Treatment Plant Improvement History

1935

The Springfield Wastewater Treatment Plant was originally constructed and placed into operation with preliminary and primary sewage treatment and single stage anaerobic sludge digestion followed by a vacuum filter.

1961

An upgrade project was completed that provided secondary biological treatment with trickling filters. Hydraulic capacity was increased to 25 MGD (million gallons per day) daily average flow, and 37.5 MGD peak flow. The anaerobic digestion system was upgraded to two stages with the addition of a secondary digester with a floating cover for gas storage.

1972

The preliminary treatment process was expanded and upgraded to dual units for screenings and aerated grit removal. A chlorine contact basin and storage building for one-ton containers was added to improve the disinfection process.

1988

The plant was upgraded to advanced secondary treatment by adding complete mixed activated sludge in tandem with the trickling filters. Dechlorination and post aeration were added after the disinfection process. This project also included a new Operations and Laboratory building.

1995

Mechanical sludge dewatering by belt filter press and covered storage were constructed to replace earthen lagoons. Land application of sludge was transferred from in-house staff to private operators.

2000

At this time, the following improvements were completed:

Combined sewer overflow screening and other headworks improvements.
Anaerobic digester structural renovations and new process heating system.
Effluent sewer expansion for peak flows handling.
Conversion from gaseous chemical disinfection to aqueous chemical disinfection.
General repair and renovation to buildings and structures.
Installation of mechanization and electronics for a SCADA system for process automation.

2009

An effluent pump station was added.

2015