The day after city hall said the frozen pipes issue has been resolved for the season, civic officials said they’ll now start a key component of the discoloured water containment program.
Crews from the water and waste utility will begin flushing water lines this weekend to rid the system of excessive amounts of manganese, the material identified as the cause of the brown water problem that became so widespread last year.
Geoff Patton, the utility’s manager of engineering, said crews will begin flushing water lines in River Heights and the North End.
An accelerated line flushing initiative is part of a comprehensive program to contain the discoloured water.
The city normally flushes all of its water lines on a six-year cycle, but that was fast-tracked to a two-year cycle after reports of brown water spiked last year.
The city used to have about 100 reports a month of discoloured water, but the numbers jumped in 2012 and peaked in August 2013 at 1,600 reports.
City and health officials repeatedly maintained that putrid-looking brown water was safe to drink, but did not recommend anyone drink or bathe in it or use it for cooking or laundry.
Ironically, manganese is released into Winnipeg’s water supply as a by-product of a chemical compound — ferric chloride — added to the water supply to make it easier to clean the same water lines.
The problem became severe with the construction in 2009 of a new water treatment plant. The plant filters out ferric chloride, but not manganese, which attaches to the lining of the water lines and is released with a sudden change in water flow, like water-main breaks or repairs. The manganese is released in clumps of varying sizes and floats through the water system until it’s drawn into a household line.
The utility normally starts its line-flushing in late May, but that was severely delayed this year as a result of the frozen pipes. The utility had no spare staff to do line flushing and, even if they did, they couldn’t do it because a large portion of the city’s water lines remained frozen and too many households were running their water as a precaution to prevent line freezing.
Patton said when crews move into a neighbourhood to initiate line flushing home owners are advised not to run their taps. Patton said that wasn’t possible with so many homes running their taps to prevent freezing.
But the city informed more than 10,000 households Wednesday that they can stop running their taps and the line flushing begins this weekend.
Patton said the accelerated line flushing program is one of several initiatives identified by a consultant earlier this year to contain brown water.
Other measures include:
❚ Switching to another ferric chloride that contains less manganese.
❚ Design changes at the water treatment plan to eliminate manganese.
❚ Clean and inspect the three in-town water supply reservoirs. Most of that work has been completed and the rest will be done in the fall.
❚ Curtailing third-party use of fire hydrants, which was identified as a contributing cause.
❚ Design and construction of a testing facility within the existing water treatment plant to test alternative methods.
❚ Hiring a consultant to monitor the city’s progress and independently verify manganese levels.
❚ Patton said the city has spent about $200,000 to date on the measures.
Additional crews will be put on the line flushing program and they will work longer hours, he said.
For exact street locations of water line flushing, click here and then check the area of the map where you live.
For this weekend, water lines in the North and South of Winnipeg are being cleaned.