Had the same thing here. I used to live in canyon lake tx and still go there a couple times a month to hang with friends.
https://www.kens5.com/video/news/crime/vandal-releases-arsenic-into-canyon-lake-water-supply-residents-ordered-not-to-drink-it/273-89d110e0-51df-4642-87e6-cb84c0e9cae9