EPA sets MCLs at levels that are economically and technologically feasible. Some states set MCLs which are more strict than EPA's. The level of a contaminant at which there would be no risk to human health. This goal is not always economically or technologically feasible, and the goal is not legally enforceable. Tiny living organisms that can be seen only with the aid of a microscope.
Some microorganisms can cause acute health problems when consumed in drinking water.
Also known as microbes. Testing that water systems must perform to detect and measure contaminants. A water system that does not follow EPA's monitoring methodology or schedule is in violation, and may be subject to legal action. A water system which supplies water to 25 or more of the same people at least six months per year in places other than their residences. Some examples are schools, factories, office buildings, and hospitals which have their own water systems.