Yes, if it is extremely bad, and the perptrator does nothing, and they find out about it.
In my case, the amount of pollution my old septic tank produced was about
0.001% of the pollution caused by all the deer, foxes, dogs and so on who crap all over the countryside and indeed my back garden round here.Nevertheless they made me put in a Klargerster for a 'new build' - which I was happty to do frankly, because although the occasional whiff from the old system is nothing like as bad as what cones off the Cambridge sewage works on a warm summer day, I didn't want it anyway.
Cess pits - as opposed to septic tanks - are a different matter. They really are a health hazard and te EA is right to go after them.
Most old septic tanks are rather poor, but they are a thousand times better than a cess pit.