It is only during the alum treatment process that aluminum appears to be changed to a form that may be more readily absorbed. Like tap water, bottled waters vary in their aluminum content. Aluminum may be found in some bottled waters because it occurs naturally at the source. The water provided by municipal water suppliers is safe. First, the water usually meets all provincial guidelines for purity.
Guidelines are very stringent and are designed to protect human health.
Finally, water treatment processes are carefully monitored and controlled to ensure that any process failure is immediately detected and corrected. The main responsibility for ensuring that drinking water is safe lies with the provinces. In the federal domain, Treasury Board uses these guidelines as standards for federal lands. At present, there is no health-based guideline recommending a safe level of aluminum in drinking water in Canada. Health Canada has evaluated the literature on the adverse effects of aluminum on humans and animals.