What it is
Settleable solids are measured by letting a sample stand for one hour and recording how much material settles. It is a practical measure of how much of your solids load a settlement stage will remove, and how much sludge that stage will accumulate.
Where it comes from
Heavier particles: grit, sand, soil, vegetable and meat pieces, shell, bone fragments and dense sludge. Root-crop washing, yard drainage, abattoirs and food preparation produce a lot of settleable material.
Why it matters
Settleable solids are the main cause of blocked drains and silted sewers, which is why water companies watch them. A high value with an interceptor already in place usually means it is undersized, overdue for emptying, or being bypassed at peak flow.
What can be done about it
This is the easiest fraction to deal with: screens, grit traps and a correctly sized settlement tank or interceptor, emptied on a schedule that matches your throughput, will remove most of it. A Pozzani engineer can check whether your existing tank is sized for your actual flow.
Information last reviewed 6 October 2026 by Pozzani Pure Water.