The Portland Water District (Maine) announced an upgrade to the Sebago Lake Water Treatment Facility with the addition of ultraviolet (UV) disinfection unit at the district’s facility in Standish. It is part of a $12.8 million project. When it becomes fully operational in 2014, the district’s UV water treatment system will be the second-largest in New England, behind the Massachusetts Water Resources Authority’s in Boston.
The process sends water through a reactor that is equipped with ultraviolet lamps. As water is exposed to the light, the light penetrates micro-organisms damaging their DNA so they can not reproduce and thus stoping the life cycle of the organism.
The improved disinfection system was mandated by the federal government. The U.S. Environmental Protection Agency (EPA) requires surface water treatment facilities to improve drinking water quality and provide additional protection from disease-causing micro-organisms and contaminants. To meet EPA standards, the district must operate two disinfection systems — its current ozone water treatment system and the new UV system. While EPA considers UV technology to be the most effective against cryptosporidium and giardia, they also promote multiple barriers for treating water. This means using two to three methods of disinfection in case any one of the systems fail.
The U.S. Centers for Disease Control and Prevention say cryptosporidium is a microscopic parasite that can cause diarrhea. Resistant to chlorine treatments, it is one of the most common causes of waterborne disease in humans.