Pollution Control Centre

Sewage System - (Annual report to be provided soon!)

Raw sewage is collected throughout the City of Pembroke and conveyed to the sewage plant via gravity sewers. There are also nine sewage pumping stations (Lift Stations) which convey sewage from low areas to higher areas in the collection system. The three major lift stations are equipped with standby generator sets which must be tested regularly.

The original pollution control center was built in 1967. It consisted of two clarifiers, two digesters and a control building. Chlorine was used for disinfection. In 1984 a further two clarifiers were added to meet high flows. A de-watering belt press was added as well a chemical building and a chlorine contact chamber. In 1994 remedial work was done on existing buildings and equipment to ensure compliance with Ministry of Labour guidelines and to optimize the process.

Existing facilities generally consist of:

1. Screening building with travelling bar screen and grit removal equipment
2. Four aerated grit tanks, including blowers, grit pumps and piping
3. Four primary sedimentation tanks (two circular and two rectangular), mechanical equipment including sludge pumps, flyghts and cross collectors
4. Chemical feed systems including alum for phosphorous removal and chlorine for disinfection
5. De-watering building with belt press to thicken sludge, positive displacement pumps and polymer systems. Sludge holding tanks with mixers and Muffin Monsters
6. Anaerobic sludge digesters (primary and secondary) complete with mixing system, gas collection system, boilers, sludge transfer pumps and piping with instrumentation
7. Chlorination comprises of toners with automatic changeover units and chlorinators
8. Outfall sewer pipe
9. Offices, laboratory and standby generator