What Is Turbidity in Drinking Water?

A turbidimeter measures light scattered by particles and reports a number. Source water may become more turbid during a storm. Settled-water and filter-effluent results help show how well the removal steps work. Very small amounts can matter at a filter, so appearance alone is not enough. Dirty sample cells, air bubbles, scratches, or a poor sample can affect a reading. Operators use clean cells and the approved method, check the instrument, and record the result with its location and time. A rising filter-effluent trend can call for prompt action under the plant procedure. The beginner's connection is direct: particles removed before and during filtration support the reliability of later disinfection.