The waste water treatment plant is located on the Yellow Breeches Stream, East of Boiling Springs, at the end of Criswell Drive.

The plant began operation on July 20, 1977, and is of the extended aeration type with aerobic digestion of sludge.

The original plant had a permitted capacity of .75MGD. In 1993, the plant was expanded and the capacity was increased to 1.5MGD.

50,000 square feet of reed beds were also constructed to improve sludge processing.   The reed bed system utilizes aquatic plants to dewater the sludge and increases storage capacity.

Today the sewer system consists of:

• The 1.5MGD treatment facility
• 11 Regional pumping stations
• 70 Miles of sewer mains
• 1,666 Manholes
• 3,943 Customers

In addition to it's own plant capacity, the South Middleton Authority owns 200,000 GPD capacity in the Mt. Holly Springs treatment plant, and 1.01 MGD in the Carlisle Borough treatment plant, in order to service South Middleton residents in those areas.