Coagulation: The destablization and initial aggregation of finely divided suspended solids by the addition of a polyelectrolyte or a biological process.

Cryptosporidium: A protozoan parasite that can live in the intestines of humans and animals.

Floccule or Floc: Small, gelatinous masses formed in water by adding a coagulant, or in wastewater through biological activity.

Flocculation: Gentle stirring or agitation to accelerate the agglomeration of particles to enhance sedimentation or flotation.

Giardia Lamblia: A protozoan parasite responsible for giardiasis.

Microfiltration membranes: A low-pressure membrane filtration process that removes suspended solids and colloids larger than 0.1 microns.

Nanofiltration membranes: Low pressure reverse osmosis. Used for softening, and organic removal, including color.

Ozone Resistance: The ability of a material to resist the oxidizing power of ozone.

Rapid Mix: A physical water treatment process that involves rapid and complete mixing of coagulants or conditioning chemicals.

Reverse Osmosis: A method of separating water from dissolved salts by passing feedwater through a semipermeable membrane at a pressure greater than the osmotic pressure caused by the dissolved salts.

Sedimentation: The removal of settleable suspended solids from water or wastewater by gravity in a quiescent basin or clarifier.

Silt Density Index: A measure of the fouling tendency of water based on the timed flow of a liquid through a membrane filter at a constant pressure.

Total Suspended Solids: The measure of particulate matter suspended in a sample of water or wastewater. After filtering a sample of a known volume, the filter is dried and weighed to determine the residue retained.

Turbidity: Suspended matter in water or wastewater that scatters or otherwise interferes with the passage of light through the water.

Ultrafiltration: A low-pressure membrane filtration process that separates solutes in the 20-1000 angstrom (up to 0.1 micron) size range.