[Paridel]

It wasn’t urine which spread polio, but fecal contamination.

No arguments here. I personally don't understand why you would have an open air reservoir when terrorists are considering going after our water supplies, but some guy peeing it is no reason to drain it. I was just trying to explain why pools are closed when someone defecates in them.

-paridel

[hellbender]

I doubt that anyone could put enough of something into a reservoir to threaten the health of many people. For one thing, the dilution would be enormous, and many contaminants would biodegrade. For another, public water supplies are filtered and disinfected.

The problem with crapping in a pool is that someone could actually ingest raw solid fecal matter (yech).

It's amazing that millions of people drink from domestic wells in close proximity to their own or their neighbors' septic systems. Quite literally, they are drinking their own wastewater, yet with modern design and construction, there is little risk.