This is defined as acceptable levels as recommended by the U.S. Environmental Protection Agency. Detection Level is the level at which the laboratory's equipment and procedures were able to produce results within normal acceptable limits of accuracy. Hardness is the term applied to water containing calcium or magnesium salts. Hard water, when heated, develops hard scale on pipes, cooking utensils and other metal objects. The life and efficiency of heating equipment are decreased by the production of the hard scale on heating coils or elements.
Hard water causes soaps to curd in the water rather than make a lather.
The concentration of these gases usually is not reported. However, objectionable taste and odor and high acidity may indicate their presence. Carbon dioxide results primarily from decaying organic matter in water-bearing soils. It accelerates corrosion of iron, brass, copper and aluminum, causing rust-colored stains from copper piping. Hydrogen sulfide comes from a sulfur source, usually accompanies iron in water, and releases a rotten-egg odor.