Waste Water Pollution Control

The mission of Pollution Control Facility is to collect and provide proper treatment of the City's residential, commercial, and industrial wastewater for the lowest practical cost to the residents and ratepayers in a prudent, reasonable and responsible manner.



The Water Pollution Control Facility (WPCF) is a fixed film, secondary treatment wastewater facility, utilizing Rotating Biological Contactors (RBCs).The facility was constructed in 1975 and upgraded in 2003. With the completion of the upgrade, the WPCF is now capable of providing full secondary treatment for an average daily flow of 1.7 Million Gallons per Day (MGD) and up to 4.7 MGD of flow (peak hourly), and provide primary treatment with disinfection for up to an additional 11 MGD of flows. Flows beyond 15.7 MGD will be discharged through the City's licensed CSOs.


Major treatment processes for the upgraded WPCF include influent pumping facilities; fine screening via a mechanically cleaned step screen with a backup manual coarse bar rack; grit removal via a two speed vortex system; primary treatment with two primary clarifiers; a storm flow treatment system that includes pumping, flow metering, primary treatment, disinfection, dechlorination and sampling facilities; a secondary treatment system which includes RBCs with the ability to be operated in a "hybrid" fashion (fixed film and supplementary suspended growth treatment), two final clarifiers, disinfection, dechlorination and sampling facilities; return and waste sludge pumping facilities; sludge handling system, which includes sludger storage, pumping and dewatering facilities; and a new instrumentation and control system, including a Supervisory Control and Data Acquisition (SCADA) system.


Collection System

The City of Old Town's wastewater collection system contains approximately 25 miles of sewers, 500 manholes, and six pump stations. It serves both commercial and residential interests, with approximately 1,900 Old Town resident accounts (including parts of the Stillwater section of Old Town) and approximately 680 Milford users utilizing the system. Portions of this collection system date back to the 1890's and as such are subsequently discharged to the Penobscot River.

In addition to the licensed outfall at the plant, the City of Old Town has three licensed combined sewer overflows(CSOs).  Two discharge to the Penobscot River and one to the Stillwater River. The CSO locations are listed below: 

CSO #002 - Prentiss Street - 24 inch overflow

CSO #003 - Gilman Falls Avenue - 10 inch overflow

CSO #004 - Stillwater Avenue - 8 inch overflow


Two other CSO discharges exist, but have been deactivated. An 8 inch overflow in the Great Works area of Old Town which has been plugged; and an 8 inch overflow directly connected to the College Avenue Pump Station Wetwell (Stillwater System), where its valve has been manually closed.


The WPCF is staffed by 7 employees.

A Superintendent, an Assistant Superintendent, four Assistant Operators, and one Office Manager.


Weekend and holiday duties include a plant inspection and any required daily laboratory analysis.