Silver is a relatively rare metal originating from natural sources and from industrial waste. Silver is used in many applications including photographic materials, alkaline batteries, jewelry, coins, mirrors and tableware. Silver also has higher electrical and thermal conductivity than other metals so it is also used in making certain electrical equipment.
What do results mean? Is it regulated?
Silver is regulated as a secondary contaminant as it does not cause any known health effects. They have established a Secondary MCL for silver at 0.10 mg/L.
Skin discolorations are a cosmetic effect related to the ingestion of silver. This effect, called argyria, and does not impair body function. Argyria has never been found to be caused by drinking water in the United States. A standard has been set, however, because silver is used as an antibacterial agent in many home water treatment devices, and so presents a potential problem which deserves attention.
How do you test for Silver?
Silver can tested for in the field using a colorimeter method based upon Standard Method using a Dithizone to produce the color change.
Laboratories analyzing drinking water samples can utilize various methods including EPA method 200.8 which utilizes an Inductively Coupled Plasma (ICP) or the Standards Method 31138 which uses Graphite Furnace.
Water Treatment Options
Silver is often used in water treatment devices as a bacteriostatic agent, meaning it inhibits the growth of bacteria.