The sequence of steps taken, beginning with unpurified water, which results in purified water delivered through a water system to the ultimate consumer. This sequence would normally include most or all of the following:
- Begin with unpurified water;
- Screening – removal of leaves, sticks and large foreign material;
- Pre-Chlorination – removal of disease organisms, bad taste, and odors;
- Pre-Settling – settling out large dirt particles;
- Flash Mix – a process in which chemicals are added to cause fine dirt to clump together;
- Coagulation/Flocculation – a process in which flash mix particles are gathered and made even larger;
- Sedimentation – a process in which gravity is used to settle out the large particles formed in coagulation/flocculation;
- Filtration – removal of any remaining particles; water is at least 99 percent particle-free at this point in the process;
- Final Chlorination – removal of any remaining disease organisms and adds necessary chlorine to prevent microbe regrowth in the distribution system;
- Corrosion Control – a step in which chemicals are added to neutralize the corrosive effects of “soft” water systems, thereby preventing damage to plumbing and fixtures;
- Finally, effluent pumps send the purified water to residential, commercial, and industrial establishments.
Purify (Water) — To rid water of impurities or pollution. See Purification Process (Water).