The town of Sackville is flushing out watermains this week and next, so residents may notice sediment or discolouration of water.
We here at Tantramar Report were curious about what’s involved in the process and why we do it, so we spoke with town engineer Dwayne Acton to find out a bit more about the annual process.
Hear this story as reported on Tantramar Report:
The need for the flushing program starts way back when Sackville first started pulling its water from the current reservoir. “Our water for years was hard, very hard in iron and manganese,” says Dwayne Acton. “And that iron and manganese was just deposited in the pipes over so many years.”
“In the late 90s, we built the water treatment plant to remove the iron and manganese,” says Acton, “but the problem is that we have pipes that date back to the 30s that have all these deposits inside the pipes. So this is the reason we do the flushing.”
Acton says whenever there’s a watermain break, and there have been a few recently, the velocity of the water gushing through the system loosens the material from the pipes.
The flushing program does something called uni-directional flushing, systematically opening and closing valves to clean each section of pipe, starting from the treatment plant.
“We use our fire hydrants to gain additional velocity that the system normally does not see, to slough off or to pull this material off the sides of the pipe and get it out through our hydrants,” says Acton. “We’re trying to pull as much of the sediment out of the system that may be just sitting there at the bottom of the pipe or on the sides of the pipe.”
Aqua Data, a Dartmouth, Nova Scotia company, does the annual unidirectional flushing program for Sackville. The company maps out sequences for the flushing program to strategically clean sections of pipe.
Acton likens the shape of the distribution system to a tree.
“We’ll do the main trunk of the tree, our main transmission watermains, and then we’ll come back, and we’ll start pulling water up the side limbs or the side streets, and cleaning them as we move along throughout the town,” says Acton.
Unfortunately, Acton says, the flushing program does mean some discoloured water can get “lost” in the system, or just not make it out of the hydrants. “Let’s face it, it’s almost virtually impossible to pull every little ounce of dirt that you’re trying to get out of there, out of the system.”.
One of the factors making it difficult to get all sediment out of the system is the fact that people need to keep using the water system even as its being flushed. That can cause dirty or discoloured water to get pulled the wrong way, instead of sending it out a fire hydrant.
Acton says when flushing is happening nearby, residents should avoid using water for a short period of time, to avoid pulling dirty water into their house system. But afterwards, it’s a good idea to flush out your water system a bit. In fact, it might be a good time for other home water system maintenance.
“Over the whole year, people can get sediment in the bottom of their hot water tanks,” says Acton. “So it’s a good procedure as a homeowner to try to flush your hot water tanks out annually as well.”
Acton says the nature of the flushing program is such that its hard to predict how long each section of the sequence will take. But he says residents can call public works in the morning to find out where the flushing is happening that day. The number for Sackville Public Works is 364-4960.
