U.S. Drinking-Water Systems Still Haven't Defeated This Nasty Parasite

The U.S.’s largest-ever outbreak of waterborne illness—cryptosporidiosis—hit Milwaukee 30 years ago. Why are many other water systems still vulnerable to the same parasite today?

https://www.scientificamerican.com/article/u-s-drinking-water-systems-still-havent-defeated-this-nasty-parasite/