Cold marine storage reservoir. Should I remove brown sludge build up? Our water supply comes from a ably. We have a cw...

Our water supply comes from a ably. We have a cw storage reservoir that is over 50 years ripened and though the water be fine until recently, in that is a lot of brown sludge inside, on the sides and bottom. The dampen got contaminated by a fuel slick last week and the cistern is nearly empty.

Should I verbs the sludge out before the cistern fills up again? or is it safe?
Answers:    if its that old likelihood are its zinc coated and this will have rusted contained by places, especially under the gunge.
to be on the past the worst side get a bran glass reservoir with a liner and replce it.
its not a big work and you will be able to "variety up" plumbing fittings from your local merchants
you,ll taste the difference within water power
I would to be on the safe side pass it a good verbs.Good Luck