The Environmental Protection Agency has approved a new flocculation process that effectively filters cryptosporidium out of pool water.
Research conducted at Auburn University in Auburn, Ala., and by Jeff Williams, Ph.D., at HaloSource in Redmond, Wash., found that cryptosporidium can be trapped in a sand filter without reintroducing it into the pool.
The application uses a positively charged, water-soluble polymer to catch crypto (which is negatively charged) and form it into a larger clump. A second application then stabilizes the clump and prevents it from unraveling and filtering out of the sand bed. The two-step process flocculates particles down to 0.5 microns. Crypto is between 4 and 6 microns.
The application does not destroy the pathogen, but because the process creates a stable flocculated clump, it can be removed through backwashing. Studies conducted at Auburn University show a 99.9 percent reduction of crypto when applying the flocculent process.
The process also has proven effective in trapping chloroforms, algae, oils and organic matter as well. It therefore works to prevent water turbidity. With space between particles in a sand filter at approximately 50 microns, most cannot effectively trap crypto and other pathogens because of their small size. Crypto is particularly worrisome to facility operators because it takes nearly seven days to be destroyed by chlorine due to its tough outer shell.
According to Williams, this is the first flocculation process that effectively traps crypto, and recently was given approval by the EPA. ?This is a monumental breakthrough for public recreational water facilities to improve quality and reduce risk,? said Williams, chief technology officer of the health sciences company that focuses on specialty polymers and their use in water treatment.
He said the application provides another layer of protection against crypto along with proper pH balance, chlorine levels and use of UV.
Cryptosporidium is a parasite that causes vomiting, diarrhea, fever, weight loss and other symptoms. It can be spread through fecal matter introduced into a recreational water setting.