They did it because the county was going to shut off their water if they didn't.
They did not and do not believe that sanitary sewers are a risk factor for untreated body wastes from an Ebola patient, and I don't, either.
Ok, I did find this, but I am not sure who to believe anymore. Sorry if I was spreading false information.
"Because of Ebola’s fragility when separated from its host, bodily fluids flushed by an infected person would not contaminate the water supply. Researchers believe Ebola survives in water for only a matter of minutes. This is because water does not provide the same environment as our bodily fluids, which have higher salt concentrations. Once in water, the host cell will take in water in an attempt to equalize the osmotic pressure, causing the cells to swell and burst, thus killing the virus."
Ebola Information Released for Water and Wastewater Utilities
What about private septic systems?