Sediment

What is Sediment?

Sediment is the catch-all for solid particles suspended in water: sand, silt, clay, rust flakes and pipe scale. It comes from well water, from disturbed water mains and hydrant flushing, and from corroding iron pipes and water heaters inside the home. Cloudy water, grit in the aerator and reddish-brown stains are the usual signs.

Sediment is mostly a nuisance rather than a direct health hazard, but it is not harmless. Particles shield bacteria and parasites from disinfectant, which is why utilities are held to a turbidity standard, and rust particles can carry lead and other metals that were bound to old pipe surfaces. It also clogs appliances and wears out the finer filters downstream.

On a filter, "sediment" is the mechanical claim: a pleated or spun cartridge rated in microns (5 µm is typical, 1 µm is fine) simply strains the particles out. It removes nothing that is dissolved — no chlorine, metals or chemicals — which is why sediment filters are usually the first stage in front of carbon or reverse osmosis rather than the whole system.

Commonly found in: Municipal tap water, Well water, Water filter claims, Lab-tested products

Sources: Surface Water Treatment Rules · National Primary Drinking Water Regulations