Nickel is not commonly found in nature as a pure metal. Pure nickel is a hard silvery white metal. It is often combined with other metals such as iron, copper, chromium and zinc to form alloys. These alloys are used to make coins, jewelry and useful items like valves and heat exchangers. Nickel is often used in electroplating and is used in making stainless steel. Many nickel compounds dissolve fairly easily and can produce a green color. Additionally nickel can enter the water from mining and refining operations. Nickel is naturally occurring in soil and is found in metaphoric rocks coming from volcanic activity. Nickel is also found in meteorite and on the ocean floor.
The absorption of dietary nickel from the gastrointestinal tract appears to be quite low, with the majority of nickel passing through the body. Nickel can be present in drinking water as the result of acidic water attacking nickel-based material.
What do the results mean? Is nickel regulated?
While the US EPA does not regulate nickel. The World Health Organization originally established a level of 0.02 mg/L for nickel in 1997. In 2006, the WHO raised the guideline level of 0.02 mg/L to 0.07 mg/L as a result of further scientific studies.
How do you test for nickel?
Laboratories analyzing drinking water samples can utilize various methods including EPA method 200.8 which utilize an Inductively Coupled Plasma (ICP) or the Standards Method 31138 which uses Graphite Furnace
Water Treatment Options
Nickel can be removed using distillation or reverse osmosis. Most nickel in drinking water is coming from a fixture that contains nickel, possible due to acidic conditions or a low pH level, so you may have to correct an acid condition with chemical feed or neutralizer.