Ultraviolet Treatment for Home Rainwater Systems
Ultraviolet (UV) is the logical choice for rainwater harvesting systems that supply water to homes.
When rainwater is held in a cistern to be pumped to the home, it is subject to microbial contamination. Standing water will eventually produce some microbes. The logical choice to assure that it is safe for drinking is to run it through an ultraviolet purifier on its way to the point of use. UV eliminates bacteria, cysts (giardia and cryptosporidium), and most water-borne viruses.
UV is a perfect addition to rainwater systems because it is a clean, easy-to-use technology that does not add chemicals or objectionable tastes or odors to the water. UV produces no by-products.
Since rainwater is naturally soft and iron-free, the only pre-treatment needed is a sediment filter in front of the UV unit to assure that the water is particulate-free. Adding a carbon prefilter can improve the taste and odor, but it is not essential.
UV needs 110 volt electricity, and it should be installed as close to the point of use as possible. UV on rainwater applications is virtually trouble-free. There are never chemicals to add. The only regular maintenance is a lamp change once a year.