What it is
Silver is a precious metal with antibacterial properties. It is almost never present in natural water at measurable levels, so a result above the limit of detection is a clue about the treatment or plumbing on the supply rather than the source.
Where it comes from
The commonest source is a silver-impregnated filter or a silver-ion disinfection unit, both sold for private supplies and for some domestic filter jugs and cartridges, which release a small amount of silver into the water. Some solders, brazing alloys and dental or industrial waste are occasional sources. It is included in the Scottish new-build set as a check on the materials and treatment fitted to a new supply.
Why it matters
The World Health Organization does not set a health-based guideline for silver in drinking water, because the levels found are far below those that cause harm. Very high intake over many years can cause argyria, a harmless but permanent grey discolouration of the skin. There is no UK regulatory limit, so your result is reported for information against the laboratory's limit of detection.
What can be done about it
If silver is detected, check any treatment units on the supply for silver-based media and confirm they are being serviced to the manufacturer's schedule. A unit releasing more silver than intended is usually one that is past its service interval. Reverse osmosis will remove silver if required, but the better fix is at the treatment unit.
Information last reviewed 17 October 2026 by Pozzani Pure Water.