AWWA Water Treatment Operator Certification Practice Test 2025 – Complete Exam Prep

The primary function of a sedimentation tank in water treatment is to allow sediment to settle. This process is crucial in the treatment workflow as it helps to remove suspended solids and particulates from water. When water is introduced into the sedimentation tank, it flows slowly, giving heavier particles, such as sand, silt, and organic matter, the opportunity to settle to the bottom due to gravity. This settled material is then usually removed as sludge.

By effectively reducing the concentration of these particles, the sedimentation process enhances the efficiency of subsequent treatment steps, such as filtration and disinfection, resulting in clearer and cleaner water. It's an essential stage that precedes any chemical treatments or disinfection processes aimed at further purifying the water. This role in particle removal is why sedimentation is often one of the first steps in water treatment processes.