Portland has a schedule to replace its open finished drinking water reservoirs with enclosed storage by December 31, 2020
"A finished drinking water reservoir contains water that has been through all the treatment steps required by the federal Safe Drinking Water Act and can be delivered to the public without further treatment."
One Man's Pee Pushes Portland To Flush 38 Million Gallons Of Water
"Though they concede it's unlikely the public was endangered, officials in Portland, Ore., have decided to drain 38 million gallons of water from a reservoir after a young man was observed urinating into it on Wednesday."
Oregon Drought Watch
Here's How Long That Teen Would Have to Pee in the Portland Reservoir to Make It Unsafe to Drink
"A teenager urinated into one of the city's drinking water reservoirs the other day. That's gross, sure, and aggravating-what a brat!"
What Contaminates Are in Water
"The sources of drinking water generally include rivers, lakes, streams, ponds, reservoirs, springs, and wells."