The Ann Arbor City Council has approved $3.8 million worth of upgrades to improve the city’s water system. $3.4 million of that money will go to UV-treatment upgrades in order to combat a parasite called cryptosporidium.
Commonly called crypto, the parasite takes up residence in the intestines of people and animals and causes gastrointestinal issues, including diarrhea. The other $406,800 has been allotted for PFAS chemicals.
Cryptosporidium was first detected at elevated levels in Ann Arbor’s source water in 2014. Those levels spiked in December of 2014, and sampling since then shows crypto’s presence in Ann Arbor’s source water as recently as last month.
Samples from last month show levels of cryptosporidium that, based on the Environmental Protection Agency’s guidelines, require additional treatment from the city to disinfect it. The Michigan Department of the Environment, Great Lakes and Energy, then called the Department of Environmental Quality, informed the city of the additional protection requirement in 2017. In order to be in compliance, the UV-system must be installed by June 2020.
Brian Steglitz is the Water Treatment Manager for the City of Ann Arbor. He says the city used to use ozone to disinfect crypto.
“Having UV as another, you know, disinfectant tool in our toolbox really increases the robustness of our disinfection practices to address other things that are not as effective at being killed by ozone, and crypto is one of those things.”
He says, in general, a UV system is a good tool to have, since it can help with other viruses and bacteria.
“So you sort of need, you know, this assortment of techniques in order to meet all of the different types of things that we have to address in water treatment. So UV definitely improves our ability to address microbial contaminants.”
He says the city is on track to complete the UV-system upgrades by the June deadline.
Steglitz also says in the grand scheme of things, the nearly $4 million the city is spending now is a moderate investment. Steglitz says the city has plans to upgrade old infrastructure, a project that may cost up to $100 million.