Does the EPA regulate both health and aesthetic contaminants?
For health effects contaminants, the U.S. EPA establishes Maximum Contaminant Levels (MCLs) for those known to cause, or suspected of causing, health problems. The MCL defines the highest concentration allowed in public water supplies. For aesthetic contaminants, the water may be safe to drink, but not very pleasant because of an undesirable taste, odor, or color. Some water may also stain clothes and fixtures, corrode plumbing, or form a scale and film. Secondary Maximum Contaminant Levels (SMCLs) are usually recommended by the EPA for these aesthetic water quality factors. SMCLs are useful guides for evaluating the suitability of water for drinking, bathing, clothes washing, cooking, and other domestic uses.
