Eastern Passage WPCP

Plant Statistics:

Plant process:

Preliminary treatment- Sewage entering is screened by automatic units which remove items such as plastics, rags, and sticks. A grit chamber allows heavy inorganic (non- treatable) particles to settle to the bottom of the grit chamber where they are removed. Air emissions from the grit room areas pass through a two stage air scrubber system before being discharged to the atmosphere: Stage 1- air is passed through a wet acid phase (pH 4) which removes odour causing nitrogen compounds such as ammonia and amines. Stage 2- a wet base/sodium hypochlorite phase removes and oxidizes acidic sulfur compounds such as mercaptans and hydrogen sulfide. Following preliminary treatment, the wastewater flow proceeds to five primary clarifiers which allow heavier organic solids to settle out and any floating materials, for example, grease and oils to be removed by surface skimming systems. All primary clarifiers are covered by fiberglass enclosures for odour control purposes. Approximately 40%-50% of suspended solids and 35%-40% of organics (B.O.D.5) are removed at the primary clarification stage.Sludges captured in the primary clarifiers are pumped by means of an automatic control arrangement, to the anaerobic digester. This is a biological process by which anaerobic bacteria metabolize and stabilize organic particles over a 20-30 day period. A major by-product produced, methane, provides the majority of plant (heating) fuel requirements. Treated sludges are ultimately removed and transported to the Aerotech Park Biosolids Lagoon.

Primary effluent proceeds to a two stage disinfection stage which performs additional clarification and destruction of pathogenic (disease causing) bacteria. A chlorine solution originating from a chlorine gas system located in the main control building is added to the wastewater flow prior to entering the chlorine contact tanks.