WCW26

The historical water treatment plant (WTP) at the Town of Moosomin produced finished water that was generally in compliance with Maximum Acceptable Concentration (MAC) parameters such as arsenic, iron, and manganese. However, the plant had no process to improve the aesthetics of the finished water which were elevated TDS and hardness. The existing graver style filters had also far exceeded their design life and required increasing operator attention to maintain compliant effluent qualities.
To achieve improvement to water aesthetics, KGS Group proposed the implementation of biological filtration followed by membrane filtration technology. The biological filtration system termed Mangazur offered by Veolia was piloted with very favorable results reducing manganese from 1.2 mg/L to less than 0.05 mg/L and filtration rates as high as 19.5 m/hr (8 gpm/ft²). Given the mature state of membrane technology, the membranes were not piloted.
Based on the success of the pilot, the decision was made to utilize Mangazur for full-scale implementation. Two 2.14 m diameter filter vessels were selected each with filtration areas of 3.57 m² for a total of 7.14 m². At a rate of 19.5 m/hr, the two filters could each produce treatment rates up to 70 m³/hr for a total pre-treatment rate of 140 m³/hr.
The membrane filtration system that followed the Mangazur consisted of two primary Reverse Osmosis (RO) skids that operated at 75% recovery and a third brine skid that treated the reject water from the two primary units operating at 50% recovery. The purpose of the brine skid was to increase overall recovery which was estimated at 88% for the complete membrane system. This 13% reduction in rejected wastewater took significant pressure off the existing sanitary infrastructure.
The primary skids were each sized to produce 39 m³/hr for a total of 78 m³/hr. The brine skid was sized to produce 13 m³/hr and the overall total membrane production was 90 m³/hr; total feed rate with both primary skids running was 103 m³/hr.
To produce a stable finished water, the design blended 25% of the Mangazur effluent with the membrane permeate. With both membrane skids running the blend rate was 22 m³/hr.
Although the raw water supply wells had been MPA tested confirming groundwater, the proximity to the lake presented the possibility that the supply wells could be declared GUDI in the future. Given this possibility additional measures were taken during the design to help accommodate a potential well designation change. This included the installation of UV disinfection and a cartridge filter rated for 3-log Crypto/Giardia on the blend line. Virus inactivation will still be provided through chlorination with CT provided by the treated water reservoir.
The historical WTP utilized chlorine gas for primary and secondary disinfection. Given the proposed treatment changes significantly reduce the total chlorine demand, the upgraded design moved to use sodium hypochlorite. The chlorine gas feed and associated equipment were abandoned.
The full scale WTP was commissioned in late 2025 and is currently producing high quality finished water for the community.