EMEGs are used in the public health assessment process to identify contaminants of concern. They may consist of the source of water used in decontaminating and steam cleaning the equipment. At a minimum, one sample from each event and each source of water must be collected and analyzed. Formation is often accompanied by oxidation or other chemical reactions. For example, in water, one part per million equals one pound of a chemical per million pounds of water.
Percolation is the volumetric flux per unit area of soil.
It represents the minus base 10 logarithm of the concentration of free hydrogen ions. The value of 7 represents neutrality. In general, the greater the porosity, the more readily fluids may flow through the soil. An exception is clay soils, in which fluids are held tightly by capillary forces. Quality control is the responsibility of all those performing hands-on operations in the field and in the laboratory.