It seems odd to me that you'd have a waste dump path in such a place which didn't have a secondary decontamination step in it. Running the water through UV sterilization would be an obvious move, and incredibly cheap considering the danger.
>>Drake demonstrated that poliovirus is able to undergo multiplicity reactivation.[23] That is, when polioviruses were irradiated with UV light and allowed to undergo multiple infections of host cells, viable progeny could be formed even at UV doses that inactivated the virus in single infections.