This is a legacy version of the WELL Building Standard. Please check the latest version here.

Inorganic contaminants

Inorganic contaminants


To limit the presence of inorganic contaminants in drinking water.


While there are numerous metals that are necessary for healthy body functions, high levels of these essential metals can be harmful to health. Many dissolved metals that contaminate water supplies can be acutely or chronically toxic. Contamination levels vary widely by geographic location and water source, spurring the need for localized testing. Exposure to even minute amounts of certain metals such as lead and mercury through drinking water has been linked to developmental delays and deficits in learning abilities in children, as well as high blood pressure and kidney problems in adults. If necessary, reverse osmosis (RO) systems or Kinetic Degradation Fluxion (KDF) filters can remove dissolved metals at the point of delivery.

Part 1
Dissolved Metals

All water being delivered to the project area for human consumption (at least one water dispenser per project) meets the following limits:
Lead less than 0.01 mg/L.
Arsenic less than 0.01 mg/L.
Antimony less than 0.006 mg/L.
Mercury less than 0.002 mg/L.
Nickel less than 0.012 mg/L.
Copper less than 1.0 mg/L.