CWWA’s Drinking Water Quality Committee submitted comments on Health Canada’s new proposed guidance for pH in drinking water. As always the Committee is appreciative of the extensive background information given in the Guidance produced by Health Canada and the Committee on Drinking Water. 

 

The new proposed guideline recommends an acceptable pH range of 7 to 10. for drinking water in order to achieve water quality objectives and corrosion control. While our members were generally supportive of the recommendation, they did identify a few times where it could be problematic – for example the City of Calgary finds that during spring run-off when extra coagulant may be required, their finished water can have a pH slightly lower than 7.0. In order to comply with the new recommendations the city would need to add pH adjustment.

 

Another Committee member has found that pH levels impact chlorine residuals in the distribution system, and that some utilities may actually need to maintain below the maximum acceptable range to maintain chlorine residuals.

CWWA’s comments are on our website.