To the editor:
In response to the March 29 letter to the editor regarding: Manganese removal plant not required for 108 water
Since 1996, the Cariboo Regional District has been sampling and monitoring manganese concentrations in the two wells that supply raw water to the 108 Mile Ranch water system. Well No. 1, located near the south end of Sepa Lake, contained total manganese at a concentration of 0.42 mg/L in 1996 and increased to over 1.00 mg/L in 2002. At that point, the well was taken out of use (1 mg/L = 1 ppm).
Well No. 2, located near the north end of Sepa Lake, initially had a total manganese concentration of 0.22 mg/L in 1996. This has increased to over 0.40 mg/L in recent years with a total manganese concentration of 0.44 mg/L measured in 2017.
These concentrations exceed the 0.05 mg/L Aesthetic Objective standard outlined in the Guidelines for Canadian Drinking Water Quality’s Drinking Water (these guidelines can be found by searching ‘Canadian Drinking Water Guidelines’ at www.canada.ca). The manganese in the water is problematic because it precipitates out of solution and builds up as a sludge in distribution and service lines. It also causes staining of laundry and fixtures in homes.
The manganese levels were one of the main reasons the CRD conducted a referendum in 2016 to borrow $2 million to help pay for the 108 Mile water treatment plant project. Eighty-one percent of the 515 residents who voted said yes to the increased requisition, which meant the parcel tax increased from $135 per year (which was paying for past infrastructure works) to $250 per year for 15 years to pay off the debt and the user fee increased to $284 per year per single-family residence.
Peter Hughes, Manager of Environmental Services
Cariboo Regional District