Hi all…a document entitled “Aluminum in drinking water: Guideline technical document for consultation” has been posted on Health Canada’s website. A new health-based guideline (MAC) of 2.9 mg/L is being proposed for aluminum for the first time. The previous guideline only recommended an operational guideline (OG) concentration. While the health-based concentration is higher than past and current OGs, it is still a new MAC so utilities should carefully review this from their perspectives. It seems to be the consensus that the lowered OG (from 0.1 mg/L to 0.05 mg/L) could be more problematic than the new MAC.

See page 60 for Canadian water quality data from the National Drinking Water Survey (2009–2010) and Environment Canada’s long-term aluminum monitoring data for select river basins across Canada (2000–2015).



All comments must be received by August 30, 2019.


Purpose of consultation

“The existing guideline technical document on aluminum, developed in 1998, recommended operational guideline (OG) values for treatment plants using aluminum-based coagulants as follows: less than 0.1 mg/L (100 µg/L) for conventional treatment plants and less than 0.2 mg/L (200 µg/L) for other types of treatment systems (e.g., direct or in-line filtration plants, lime softening plants). A health-based guideline was not established at that time, as there was no consistent, convincing evidence that aluminum in drinking water could cause adverse health effects in humans. This document proposes a maximum acceptable concentration (MAC) of 2.9 mg/L (2,900 µg/L) for total aluminum in drinking water, based on neurological effects observed in rats. An OG value of 0.050 mg/L (50 μg/L) is proposed for total aluminum to optimize water treatment and distribution systems.”