"Dave Liquorice" wrote:


The normal soil bacteria will deal with traces of oil that get to the soil
without any trouble.

As a secondary question, is this heating oil the same stuff as
paraffin?

It's low octane/grade diesel.

That depends on the "heating oil". Modern pressure jet boilers use 28sec
oil which is parrafin, kerosene etc. Diesel, gas oil, etc is 35sec and
less volatile than 28sec.

There is such a boiler that goes with the tank but the CH system is
completely dismantled and will be for a year or so yet.

The OP doesn't state if this is an old steel tank or a more recent plastic
one. If plastic I'd drain as much oil out as possible and use drawing
water off from low down...

A modern plastic one, therefore light enough to roll over and empty
through the filler cap, which should mean all but what adheres to the
inside surface.

There may be a problem with the oil on the
surface depending on how the filling arrangements are done. Where is the
overflow water going to go? Can the surface layer flow back to the normal
drain, as it can with a normal down spout butt filler?

I wasn't thinking of using it with a catchment system but as an
emergency supply in hand. Fill it with a hose while there is water
available and keep until needed, so there will be no overflow. Anyway,
there's nothing to catch! It is part of this year's work schedule (never
completed) to build some largeish concrete tanks to catch the winter
rain.

Thanks.

Brian Mitchell