Aluminum in well water: guidelines and causes
The EPA's cosmetic guideline for aluminum is 0.05 to 0.2 mg/L. Health Canada's health based limit is 2.9 mg/L. Most well results are far below the health limit.
- US (EPA)
- 0.05 to 0.2 mg/L cosmetic guideline.
- Canada
- 2.9 mg/L (Health Canada).
What it is
Aluminum is common in soil and rock. Acidic water dissolves more of it, and a cloudy sample with sediment can read higher.
What your number means
- Within limitsBelow 0.2 mg/L
No taste or color effect expected.
- Worth a look0.2 to 2.9 mg/L
Can cause cloudy or discolored water. Under Health Canada's health limit.
- Above limitAbove 2.9 mg/L
Above Health Canada's limit. Retest and ask about treatment.
What to do
- Check your pH. Raising low pH often lowers aluminum.
- If the sample was cloudy, retest after running the water until it runs clear.
- Reverse osmosis removes aluminum.
How often to test
With a full panel every 3 to 5 years.
Common questions
Does aluminum in water cause Alzheimer's?
Health agencies have not found that aluminum in drinking water causes Alzheimer's. Health Canada's limit is based on effects in animal studies at very high doses.
Why is aluminum higher with low pH?
Acidic water dissolves more minerals from rock, including aluminum.
Sources: EPA secondary standards; Health Canada guidelines summary table. Limits checked November 2026.