The City of Chilliwack operates an extensive sanitary sewer system. The system is comprised of a sewer collection system, 45+ sewer pumping stations and a wastewater treatment plant.
The collection system includes:
- Inspection Chambers – access point at property line of each property connected to the City sewer for the purpose of inspecting and to aid in removing any blockages in a service line.
- Sewer Service Connection – sewer pipe connecting the inspection chamber to the sewer main.
- Sewer Main – The larger pipe which collects and conveys flow towards a Sewer Pumping Station or the Wastewater Treatment Plant. This is normally a gravity line which is sloped in order to aid in moving sewage flow in the desired direction.
- Sewer Pumping Station – a sewer pumping station consists of an underground tank, pumps, controller and a forcemain connection. A sewer pumping station is placed at the low point in a sewer collection area and the sewer mains drain towards the underground tank at the station. Pumps in the tank then pump the sewage out of the tank, through a forcemain, to a manhole closer to the wastewater treatment plant or directly to the wastewater treatment plant. The pumps are automatically controlled either through a kiosk mounted controller or a building mounted controller, depending on the size of the station.
- Forcemain – is a sewer line which is flowing under pressure from a sewer pumping station. This allows flow to be mechanically pumped from low points in the sewer system to higher points so that flow can continue on under gravity to reach the wastewater treatment plant.
- Wastewater Treatment Plant – the wastewater treatment plant receives all flow from the City’s entire Sanitary Sewer System network. It can process up to 45,000 m3 of sewage flow per day. At the wastewater treatment plant, solid material is removed and trucked away by a private company. Fluid is treated through a biological process and purified prior to the treated effluent being discharged to the Fraser River. The wastewater effluent leaving the plant is monitored carefully. You would be surprised to see that the discharge water is clear and free from particulate matter.