Surface Water Treatment & CT Compliance: Alabama Grade IV
Grade IV is Alabama's only surface water treatment classification (ADEM Admin. Code 335-10-1-.03) — it covers every surface water treatment plant in the state regardless of size, plus any groundwater plant classified as "under the direct influence of surface water" (GWUDI). Alabama's largest utilities — serving Birmingham, Montgomery, and Mobile — draw from rivers such as the Cahaba, Black Warrior, Alabama, and Tombigbee, so Grade IV content should center on conventional filtration and the federal Surface Water Treatment Rules, which do not apply to a typical groundwater plant.
The conventional treatment train
Coagulation (rapid mix of a coagulant like alum or a polyaluminum chloride to destabilize colloidal turbidity) → flocculation (slow mixing to grow floc) → sedimentation (settling out the floc) → filtration (usually ra