Are there microplastics in tap water?
Yes, but levels vary. A 2026 Milan drinking-water study found low levels of plastic particles in tap water and suggested private plumbing may add some particles.
What's actually in it
Tap water can contain tiny particles from the environment, treatment systems, pipes, and home plumbing. Not every particle is plastic. Some are natural fibers like cellulose.
Microplastics are small plastic pieces. They are hard to see, and smaller particles are harder to filter.
What the research says
A 2026 study in Journal of Xenobiotics tested water from groundwater extraction, treatment steps, a public fountain, and 10 household taps in Milan, Italy.
The study found low particle levels. Household tap water averaged 1.9 particles per liter. Plastics made up 8% of the full particle set, and cellulose made up most of it. The researchers did not find a significant increase across the supply chain, but higher variation in homes suggested private plumbing may add particles.
This study does not prove that all tap water has high microplastic levels. It does show that tap water can carry plastic particles by the time it reaches the glass.
What to do
Use a good water filter if microplastics are a concern. Store filtered water in glass food storage instead of plastic bottles.