Surface Water Treatment Plant

1

Intake Structure

2

Sedimentation

3

Coagulant

4

Flocculation Basins

5

Clarifier

6

Sludge

7

Filtration

8

Disinfection

9

Clear well

10

Distribution System

Intake Structure

Screens and withdraws raw surface water from the source. Removes large debris such as sticks, leaves, and trash before the water enters the treatment plant.

Sedimentation

Allows heavy suspended particles to settle to the bottom by gravity. Reduces turbidity and removes sand, grit, and dense solids before chemical treatment and mixing.

Coagulant

Chemicals (like alum or ferric salts) added to destabilize fine suspended particles and colloids so they can stick together.

Flocculation Basins

Gently mix the water after coagulant addition. The slow stirring encourages small particles to collide and form larger, heavier flocs that can settle out easier in the clarifier.

Clarifier

A settling tank where the flocs formed in flocculation sink to the bottom as sludge. Clarifiers remove the majority of suspended solids and significantly reduce turbidity. 

Sludge

The collected settled solids from the clarifier. Sludge is typically thickened, dewatered, and disposed of or sent for further processing.

Filtration

Water passes through layers of sand, gravel, and sometimes activated carbon. Removes remaining suspended particles, flocs, microorganisms, and fine turbidity that did not settle in the clarifier.

Disinfection

Applied to kill or inactivate pathogenic microorganisms. Ensures water is microbiologically safe before distribution.

Clear Well

A storage reservoir that allows contact time for disinfectant to work effectively. Provides short-term storage before water is pumped out to the distribution.

Distribution System

Pumps send the fully treated, safe drinking water into municipal distribution networks

MCL

highest concentration of a contaminant the EPA legally allows in drinking water and is enforceable

MCLG

a health-based non-enforceable target level for a contaminant

Nitrate MCL

10 mg/L