The Cowichan Valley Regional Water District operates 17 surface and ground water systems and 2 reclaimed wastewater treatment plants. The district treats the ground water with potassium permanganate to oxidize the high content of manganese and iron in the water. The water is then filtered through green sand filters and industrial bleach is added to the water with a target residual between 0.5 and 0.7 ppm (parts per million). The district also processes wastewater. Reclaimed wastewater is filtered and treated with UV light prior to being pumped into storage tanks, where a free chlorine residual of 1.5 ppm is maintained. The water is then used for irrigation.
Situation & Callenges
The district previously used 7 membrane analyzers from Severn Trent Services Capital Control® to monitor the free chlorine residuals in the storage tanks and at the end of the drinking water discharge lines. The analyzers experienced drift due to the challenging water conditions and required at least one calibration per month. Calibration of each unit took on average 75 minutes (including driving time to analyzer location), which resulted in 15 operator hours/unit/year or a total of 105 operator hours for all seven analyzers/year. The calibration and commissioning process takes about 24 hours, in which the analyzer cannot take any measurements. This was a big concern for the district. The analyzers also required several spare parts, which resulted in annual expenses of $500-600 per unit.
The Cowichan Valley Regional Water District was interested in trying other amperometric chlorine measurement systems. They trialed another membrane-covered amperometric system, but were not satisfied due to similar preventative maintenance requirements and the need for electrolytic gel refills for the sensor.
The Cowichan Valley Regional Water District bought the first Krypton® Multi analyzer in 2018 and was impressed with the performance. The unit could be easily installed, started up and was ready to deliver precise readings within one hour. Once the ASR® automatic sensor cleaning schedule was optimized based on their specific water conditions, the sensor did not require any preventative maintenance. The unit has precisely and reliably measured the free chlorine residuals despite the challenging water conditions for the last three years.
In order to improve measurements and to reduce preventative maintenance, ClearTech suggested the installation of the Kuntze Krypton® Multi analyzers to monitor the free chlorine residuals. The district liked especially Kuntze’s ASR® automatic sensor cleaning technology, which automatically runs up to once per day preventing the sensor from fouling.
Krypton® Multi analyzer
Based on the excellent experience, the Cowichan Valley Regional Water District replaced six Severn Trent Services Capital Control® systems with Krypton® Multi analyzers. The last Severn Trent Services Capital Control® system will be replaced with a Kuntze analyzer in the next few weeks. The Krypton® Multi analyzers have provided a worry-free maintenance solution to the Cowichan Valley Regional Water District and will save about 105 operator hours per year, which will be invested into other important operator work.