How Water Treatment Plants Work

Water treatment is critical to the health and safety of your community, and as recent events have shown, having poor quality water or water that is not properly treated at a water treatment facility can have detrimental health consequences on the population. In order to provide good quality water to your constituents, it’s important to have a water treatment plant that is working properly.

Water System Sizes

The drinking water standards that a treatment facility must meet are different depending on the size of the facility and the number of people it serves. Generally they fall into one of three different categories:

Community Water System – with 54,000 of these in the U.S., they are the second largest type behind transient non-community water systems. These are public water systems that serve a fixed group of people all year-round. Generally that includes things like homes, apartments, condos, and mobile home parks in small communities.

Non-Community Water System – this type of system is also public but serves different people throughout the year. They fall into two types:

• Non-Transient Non-Community Water System serves a set population but does not provide them with water throughout the year. An example might be a school with its own water treatment that only operates 8 months out of the year.
• Transient Non-Community Water System serves different people throughout the year. An example might be water provided at a campground where the population is constantly changing.

Treatment Processes

Different water suppliers use a variety of treatment processes that can remove harmful contaminants from water that is provided to communities for drinking purposes. In some cases several individual treatment processes will be conducted sequentially to ensure the highest level of safety for the water that leaves the plant.

The Safe Drinking Water Act of 1974-2004 protects the public’s health when it comes to water from the tap using treatment methods that might include:

• Filtration – removing all particles from the water, including clay, silt, and natural organic matter, particles from other treatment processes, iron, manganese, and microorganisms
• Flocculation & Sedimentation – coagulating small particles into larger particles that settle out of the water using alum or iron salts or synthetic polymers to promote coagulation
• Disinfection – killing potentially dangerous microbes using chlorine, chloramines, and chlorine dioxide, as well as ozone and ultraviolet radiation in some cases
• Ion exchange – remove inorganic contaminants that cannot be removed with sedimentation or filtration; it’s particularly useful in treating hard water and removing harmful things like arsenic, chromium, fluoride, nitrates, radium, and uranium
• Absorption – removing organic contaminants, colors, and other things that could cause problems with the taste or odor of the water using powder-activated carbon

The exact processes that each water treatment plant chooses, and the sequence in which they are applied, is based on the contaminants contained in the raw water that comes through the system.

You can find all the water treatment plant equipment you need for your own processes at Ashton Tucker.