West 琉璃神社 city staff are recommending a $2.5 million solution to address source water quality issues in the Rose Valley Reservoir (RVR).
A $50 credit for each of the 8,500 accounts on the Rose Valley Water System is proposed, at an estimated cost of $425,000. Both initiatives would be funded through the Rose Valley Water Reserves.
On Nov. 12, a group of residents petitioned city council for increased transparency and better communication regarding water quality and testing at the Rose Valley Water Treatment Plant (RVWTP), citing concerns over manganese levels and potential health risks. The also asked for an independent review of the city鈥檚 2014 Water Utility Master Plan specifically examining the selection of the Rose Valley Reservoir (RVR) for source drinking water.
A staff report going to council on Nov. 26 states the source water quality in the reservoir has experienced changing conditions over time and more source water quality challenges are expected.
鈥淚ncreased human caused activity, climate change, and wildfire are placing additional impacts to the watershed,鈥� the report says.
According to staff, algae growth has intensified, accompanied by rising levels of turbidity, iron-related bacteria, and manganese. An update to the Master Plan is in the early stages of development.
Testing conducted after Health Canada updated its manganese guidelines in 2019 revealed that reservoir manganese levels exceeded acceptable limits at that time and in subsequent years. Residents began noticing discoloured and foul-smelling water in July 2023. Since then, city staff have worked to address the issues with varying levels of success, issuing water quality advisories whenever test results exceeded guidelines.
Chlorine pre-treatment was briefly used to combat discoloration and odour issues. However, the process is not ideal due to its interaction with organic matter, which can create disinfection byproducts. Despite this, the city maintained compliance with disinfection byproduct guidelines during the treatment period.
According to the report, without the RVWTP, residents might have faced extended water quality advisories, boil water notices, or even a 鈥渄o not consume鈥� order in 2024.
To address the manganese and related water quality issues, staff recommend using as an oxidizing agent in the reservoir. This approach, which will not produce harmful disinfection byproducts, is projected to cost $2.5 million.
鈥淭he Rose Valley Water Treatment Plant has improved the quality of water the city is providing to its customers and allows the flexibility of adjusting treatment processes to accommodate changes in the source water,鈥� the report states. 鈥淲ater quality will continue to improve as the city refines its treatment processes and source water quality.鈥�
