Secondary Treatment in the United States
Secondary Treatment in Environmental Law
Processes used by municipal wastewater treatment plants to reduce the amount of pollution released to surface waters. Primary treatment is simply removal of solids, done by flotation or settlement; secondary treatment usually involves the use of bacteria to break down the pollutants, followed by disinfection.
Now that the wastewater treatment plants are required to meet secondary treatment standards, a third level of treatment, tertiary treatment will be added. It involves further removal of suspended solids, nitrogen, and phosphorus. See also Clean Water Act; National Pollutant Discharge Elimination System; publicly owned treatment works; water pollution control technologies.
Based on “Environment and the Law. A Dictionary”.