"Nightjar" wrote in message
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On 16/08/2018 16:55, NY wrote:
"Nightjar" wrote in message
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There is absolutely no requirement to modify existing plants. All
existing plants, no matter how old, can be left exactly as built. The
requirement is that you must ensure that the outflow from the plant does
not contaminate a waterway.

Which may amount to the same: you may need either to modify your plant so
its output is cleaner, if it discharges into a waterway, or else you may
need to modify where the unmodified outflow goes (soakway rather than
waterway). One way or the other you may need to pay, even though your
system met the relevant standards when it was installed.

The result may well be that you need to spend money to clean up the
outfall, but that does not constitute a retrospective application of
current standards to the plant itself.

I think you might be splitting hairs (*) here. If you need to clean up the
outfall (or direct the outfall elsewhere), having not been required to
previously, then that is retrospective application of a modern standard onto
an old system. Where you make the boundary between "the plant" and "the
outfall" doesn't really matter.


(*) Or "splitting hares" as I saw someone write, which conjures up the image
of someone attacking a jack or a jill with a cleaver :-)