How Long Does it Take to Purify Urban Water?

Because tap water often smells bad and tastes of chlorine, people might think the water is not pure. Water quality standards for public water differ from public opinion. Public water must be pure, clean and drinkable by state and federal law. Smell and taste are considered objectionables and not issues that affect water quality.

Treatment and Flow Rates

• Where the water gets pulled from drives the length of time for treating and purifying public water for drinking. Water collected in reservoirs or pulled from rivers must go through many treatment processes before it is released for public consumption. Another factor that figures into the treatment time has to do with the flow rates of the water coming in and going out of the treatment plant.

High Flow Plants

• Urban high flow water treatment plants essentially treat water in just over two hours from the time the water arrives at the plant. This depends on what type of treatment processes are going on and the status of the water when it arrives. Additionally, under EPA guidelines only surface water is regulated. If a water treatment plant uses well water, treatment modalities change as does the time required to treat the water, which would be significantly reduced.

Treatment Process

• The treatment process of a high output plant in an urban setting screens out large debris and then mixes the water with natural materials that clump sediment together and drop it to the bottom. Skimmed top water is then sent through an ozone, chlorine or chloramine process that performs bacteria kill. A final rinse through sand and carbon filter beds polish and clean the water for consumption. Water is continually checked at various points in this process by water treatment plant operators.

Distribution

• Treated water enters the distribution system by being pumped into large storage tanks above residential areas. Water must meet over 90 regulations to be safe for public consumption. Water treatment operators are licensed by the state health department and are ultimately responsible for safe drinking water.