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GATINEAU, QC DRINKING WATER
The City's Aylmer water and wastewater plants are the most vulnerable to flooding
We sent Gatineau media a series of email questions. The answers are below
WT: Can you describe the drinking water system in Regina, (distribution watermains, treatment plant, number of users, etc.) and the main challenges it faces?
Gatineau has four plants that treat and distribute around 37 billion liters of drinking water a year to about 290 000 citizens through 1 400 Km of water mains. The treatment process includes:
- Coagulation (alum)
- Flocculation (cationic polymer)
- Setting tanks (actiflos)
- Oxidation (ozone)
- Biological filtration (activated carbon)
- Disinfection (sodium hypochlorite) and
- pH correction (lime)
WT: What is the source of drinking water?
The source for the drinking water for the Aylmer, Hull, and Gatineau sectors is the Rivière des Outaouais (Ottawa River) and the source for the Buckingham sector is the Rivière du Lièvre.
WT: Do the plants have any treatment for emerging contaminants such as PFAS, and endocrine disrupters?
The right technologies for the removal of PFAS are not yet available for plant treatment. In Gatineau, along with the modernization of our plants, we added oxidation and biological filtration with activated carbon after the coagulation as our treatment process. According to the literature, there is a substantial removal of PFAS through carbon absorption. The combination of oxidation and carbon absorption can also be useful for many other emerging contaminants. Furthermore, oxidation with ozone is recommended for many endocrine disrupters.
WT: With the increase in extreme weather events and flooding, what measures is Gatineau taking to protect its plants?
Regarding the floods, the Aylmer and wastewater plants are the most vulnerable. The situation could be improved by building dykes. Also, because of the low water levels of the Ottawa River, the City will be enlarging the inlet of the raw water chamber of the Gatineau water plant.
WT: Combined sewage overflows are a common problem in cities across Canada. What is the situation in Gatineau? What was the amount of CSO in recent years?
Gatineau has 90 combined sewage overflows (CSO) sites. For the last twenty years, the City has rebuilt many underground infrastructures. In that sense, several CSO sites have been eliminated. In addition, in 2021, 632 events were recorded. Another important issue that the City is looking into is corrosion in water remains, especially with all the long-term investments in infrastructures.
WT: Lead connections are also a common problem, how many lead connections do you estimate there are in Gatineau? What is the city doing about it?
There are currently 1 600 lead connections estimated. It is important to note that Gatineau follows the Quebec regulation on lead connections, sampling campaigns,and letters to owners.
WT: Are there other emerging issues you are looking into?
Finally, it is worth mentioning that according to our most recent Drinking Water Review (French only) the efforts of the citizens and those of the cities have reduced drinking water consumption by 10% since 2015. According to these results, Gatineau ranks as one of the best cities in the province of Quebec in terms of drinking water consumption.