Zinc in well water: taste and galvanized pipes

Zinc isn't a health concern at well water levels. Above 5 mg/L (EPA and Ontario) water can taste metallic. High zinc often points to corroding galvanized pipes.

US (EPA): 5 mg/L cosmetic guideline.
Ontario: 5 mg/L aesthetic objective.

What it is

Zinc is a common mineral and a nutrient. In tap water, most of it comes from galvanized (zinc coated) pipes and fittings, especially with acidic water.

What your number means

Within limitsBelow 5 mg/L
No taste effect expected.
Worth a lookAbove 5 mg/L
Metallic taste and possible cloudiness. Look for corroding galvanized plumbing.

What to do

Check your pH. Acidic water corrodes galvanized pipes faster.
If you have galvanized plumbing, test for lead and cadmium too, since they can come from the same pipes.
Replacing old galvanized pipes fixes the source.

How often to test

With a full panel every 3 to 5 years.

Common questions

Is zinc in water bad for you?

Not at the levels found in tap water. The guideline is about taste.

Why test for lead if zinc is high?

Old galvanized pipes can release lead and cadmium as well as zinc.

Sources: EPA secondary standards; Ontario Drinking Water Quality Standards (O. Reg. 169/03). Limits checked November 2026.