Why is polluted water entering a sinkhole a hazard?

Question

This is a chemistry question that I am supposed to answer by looking it up on the internet. Unfortunately I can not find the answer in a typical online search, so I was wondering if anyone on here might know the answer.

Answer 1

because it will be there forever

there are places where sewage has replaced good water in carbon aquifers and this is there forever

so when people pump for water they get sewage instead.

some sink holes are over a mile deep

whilst sewage that either dissolves in bigger water or goes though a composting process ,on the surface ,remains sewage that deep down ,for ever

Answer 2

It might be that dieses could brew and you could get sick.  Also the water might erode more of the sinkhole away and the whole area might collapse.