Scope
The December 2025 summary tables compile Canadian drinking-water guideline values by parameter. The table classifies health-based values as maximum acceptable concentrations, with separate aesthetic objectives and operational guidance values where those apply. This page records the heavy-metal and metalloid MAC entries that can be used as drinking-water regulatory comparators.
Exact limit and units
The values below are transcribed from the Health Canada summary table. Arsenic is recorded as total arsenic (tAs) because the table states “arsenic” without speciation; mercury is recorded as total mercury (tHg) because the table states that the MAC applies to all forms of mercury; chromium is recorded as Cr-total because the table states that the MAC is established for total chromium.
| Metal | Matrix | Limit | Unit | Basis |
|---|---|---|---|---|
| Aluminum | Drinking water | 2.9 | mg/L | drinking water |
| Antimony | Drinking water | 0.006 | mg/L | drinking water |
| Arsenic | Drinking water | 0.010 | mg/L | drinking water |
| Cadmium | Drinking water | 0.007 | mg/L | drinking water |
| Chromium | Drinking water | 0.05 | mg/L | drinking water |
| Lead | Drinking water | 0.005 | mg/L | drinking water |
| Mercury | Drinking water | 0.001 | mg/L | drinking water |
| Uranium | Drinking water | 0.02 | mg/L | drinking water |
The aluminium entry also includes an operational guidance value of 0.1 mg/L. The arsenic and lead entries carry ALARA notes, but the MACs above are the transcribed numeric values for the lookup table.
Uranium is shown for completeness because the Health Canada table lists it, but it is not loaded into data/evidence/regulatory_limits.csv because U is outside the controlled metal_species vocabulary for this ingest.
How tested
The summary table does not prescribe a single analytical method for each parameter. It states the guideline value, sources, health basis, and application notes. The lead and cadmium entries specify tap sampling considerations because plumbing can affect exposure.
Enforcement posture
The Guidelines for Canadian Drinking Water Quality are national guideline values compiled by Health Canada and used by Canadian jurisdictions in drinking-water management. The summary table distinguishes health-based MACs from aesthetic objectives and operational guidance values. This page records the MAC values as regulatory comparators and does not treat aesthetic or operational values as food-contaminant limits.
History of changes
This source is the December 2025 summary-table version. The individual parameter rows show their own publication or reaffirmation years, including aluminium 2021, antimony 2024, arsenic 2006, cadmium 2020, chromium 2018, lead 2019, mercury 1986, and uranium 2019.
How it compares
The Canadian MACs are drinking-water concentration values. They are most comparable to EU drinking-water parametric values and US EPA maximum contaminant levels. They should not be substituted for food-specific maximum levels or for product-form standards where a separate regulator sets a matrix-specific limit.
Sources
Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Change | Description |
|---|---|---|---|
| a8052bb | 2026-08-09 | major | 1 source added; contamination-profile values revised; 8 sections added |