The activated carbon filters offer an effective method to remove chlorine taste and odor and other organic substances in a water supply. Small amounts of color and low levels of hydrogen sulfide may also be removed with activated carbon. In some difficult water conditions, it may be necessary to use a different grade of carbon other than the standard grade.
The multi-media filters provide an efficient means to remove sediment and particulate matter from a water supply. Multi-media filters use stratified layers of graduated size media which offer a depth filtration process through the filter. The larger particles are filtered out at the top of the media and the bottom layers filter out particles as small as 10 microns.
The greensand filters employ a manganese-coated greensand as the main medium in the filter. Additional media are used to provide a depth filtration process, similar to the multi-media filter. The feed water must be treated to provide a continuous oxidation of iron, manganese and hydrogen sulfide for effective and efficient operation. This requires using a chemical feed pump to inject potassium permanganate into the supply water.
