By Andrea Arnold
A water conservation notice has been issued for the Village of McBride effective immediately, May 18, 2021. The notice requests that residents limit water usage where possible like dishwashing, and toilet flushing, and omit unnecessary usage of water such as car washing or pool filling for the time being.
Water restrictions and boil water advisories are not new for the residents of McBride. Each spring, as the thaw creeps up the mountain side, particles and organic materials join the flow of water into the village’s water supply.
How it works
Public Works Working Foreman and Water Plant Operator Matt Slaney explained the process water goes through as it travels through the treatment system.
“Water enters the system from Dominion Creek, through an intake pipe located in a small dammed pond,” said Slaney. “It flows to two settling tanks, each with a capacity of 60m3, to allow sediment to settle. The cleaner water then travels to the treatment plant where it is treated to intense UV exposure. The UV lights render organisms like Giardiasis and Cryptosporidium incapable of reproduction, making them harmless for consumption.”
He explained that once it has been UV treated, a very small amount of water travels through a vacuum/suction process where a predetermined amount of chlorine is added to kill the 99% of other organisms in the water.
“The amount of chlorine needed is monitored and adjusted regularly,” he said.
The chlorine concentrated water is returned to the main flow just before it enters the underground reservoir. The reservoir contains a series of wall-like partitions staggered through the 800m3 tank and the flow around the walls causes the chlorine to distribute evenly before arriving at your tap.
What to expect
A few weeks ago, residents may have noticed their water had a hint of a yellow colour.
“Yellow water is caused by melting in the lower elevations,” said Slaney. “As the water runs down the slopes into the creek, it picks up discoloured organics. Like a large organic tea bag.” This is an example of when chlorine levels are added, however the colour cannot be removed.
“As spring continues higher up on the mountain, freshet begins to be a problem,” said Slaney, referring to the widely used term to describe the thaw. “This is the season we are in now.” It is during this time, boil water advisories most often occur.
“When the turbidity levels reach 1.0 NTU for 24 consecutive hours, Northern Health, along with the village CAO will issue the advisory. (Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air). Or, there may be a water conservation advisory issued. This may seem strange as it often happens when there seems to be an excess of water available.
“The issue is not the quantity available, but the availability of quality water,” said Slaney. The purpose of restrictions is to help prevent unnecessary particles and dirt entering the system by slowing the intake from the creek. “The full reservoir can sustain the village for a minimum of two days without any new water being added,” he said. When a restriction is issued the village is trying to extend the amount of clean, treated water available, while hoping to avoid the need for further action.
When the need arises for a boil water advisory, the UV lights become less effective due to the muddiness/cloudiness of the water entering the tanks. The light can not penetrate through the murk. The action of boiling the water prior to consumption removes the organisms that may have been missed.
In light of the call for water conservation issued on May 18, 2021 residents need to understand that last year’s water situation was exceptional. Most years, the need for conserving or boiling water lasts anywhere from a few days to several weeks. The rate of thaw this year is looking more like a usual spring runoff.
How can you help?
It is important that residents respect the request for conservation as the amount of consumable/clean water is limited (without the boil water advisory). Once an advisory has been issued, the turbidity is beyond what is considered healthy and the recommendation to boil is for the health and safety of all residents.