Zurich is a community of approximately 1,000 people located near the centre of the Municipality of Bluewater. Sewage treatment facilities, consisting of a pumping station and two conventional lagoons, were designed by BMROSS and constructed in the early 1970s. In 2000, an Environmental Assessment (EA) was completed for upgrading of the sewage facilities. It concluded that the level of treatment provided at the lagoons was inadequate based on current standards, and that the facility had inadequate storage capacity for current (and future) flows. Due to budget constraints, no upgrades were carried out for several years, and the EA expired. In 2009, BMROSS completed an EA addendum and started final design for the preferred upgrade and expansion alternative.
More stringent effluent quality criteria resulted in the need to provide tertiary level treatment of the wastewater. Budget constraints required that maximum advantage be taken of the existing treatment facilities. A decision was made to add aerated lagoons, deepen the existing lagoon cells and add Intermittent Sand Filters.
The upgrades included the addition of a building to house control, chemical, and blower equipment; increased lagoon storage capacity by deepening of existing cells; installation of fine bubble aeration equipment in two aerated lagoons constructed within the original lagoon footprint; continuous chemical dosing equipment; and an intermittent sand filter system, complete with automated dosing pump facilities. The Main Sewage Pumping Station (SPS) in the community was also upgraded with larger submersible pumps, a new generator, and an improved control system. The sewage treatment facilities are now rated for an average flow of 495 m3/d.
BMROSS completed several tasks related to the final design of the facilities, including:
- Structural design of the control, chemical, and blower building and other outdoor concrete structures.
- Process design for the chemical feed and aeration systems.
- Hydraulic design for wastewater flow from the Main SPS to the final effluent discharge.
- Equipment pre-selection, through a competitive bidding process, for sewage pumps, effluent pumps, a generator, blowers, and the fine bubble air diffuser system.
BMROSS also provided contract administration and site review services. Construction was completed by late 2011. One of the more challenging aspects of the project was to complete an EA Addendum, final design, and construction within a tight Municipal Rural Infrastructure Fund (MRIF) grant program deadline. Another challenge was to expand the facilities while maintaining wastewater treatment capability.