A water purification process may include a number of different steps. To explain water purification in specific localities, it is necessary to contact your treatment facility or visit their website, if they have one. Some plants are very large and some stations only service a few homes. What follows are the steps used by my local facility.

Ion exchange is the first step in the complex water purification process. Ion exchange can accomplish several things. The facility uses it to remove various metal ions. It is sometimes referred to as "softening". In home systems it is used to balance mineral content, pH levels and remove traces of lead that can seep in through the pipes.

When this step in the water purification process is complete, if effective, there will be no heavy metals like lead, iron, mercury or cadmium. All of which can cause health problems.

Step two is Granular Activated Carbon. As, we are attempting to explain water purification, it is important to note that a water purification process may be used in the home or in a facility or both. Carbon blocks are used in both.

At the facility, there is an oversized granular activated carbon bed. In home units and at facilities where they are used carbon removes chlorine, pesticides, herbicides, and other organic contaminants. THM's or trihalomethanes, which are produced during chlorination, will also be removed by carbon.

Sediment filtration is the third step in our local water purification process. It is a simple paper sediment filter which traps larger particles like sand, dirt or grit. They need to be removed early in the process, to prevent clogging later on.

Step four in the water purification process is reverse osmosis. This is a step that has been adapted for home use, but it is only necessary when the source is particularly contaminated. Depending on the size of the pores in the membrane, it can remove a variety of contaminants, but only those that are heavier or larger than the water's molecules.

Step five is called the five micron carbon block filter. It is designed to capture small particles, those that pass through the reverse osmosis membrane.

In the next step of our local water purification process ultra violet lights are used for disinfection. It is easier to explain water purification of this type, because the design is simple. It consists of a chamber with large ultra violet light.

UV disinfection is followed by a one micro sediment filter. Oxygenation is used to further disinfect and purify. Then the resulting product is stored for use by humans.

In our area, chlorine is again added to prevent algae and bacteria growth in the pipes. So, even though our local water purification process is a good one, we still need carbon filtration in our homes to remove chlorine and THMs.

This was a very brief attempt to explain water purification. There are many other stages that can be included and in some areas, all of the ones mentioned here are not used. The best advice is to have a good water purification process for your home, because contamination can happen in an instant.