On Jun 4, 12:59 pm, M Q wrote:
I have a septic tank with round concrete lids at grade
level resting on a concrete riser.
As the concrete is a bit rough and uneven,
the lids do not seal very well.
Depending upon atmospheric and other conditions the
area is a bit malodorous.

How is a seal usually formed for such things?
Are there gaskets that are used? A ton of plumber's putty?
Something else?

Hopefully they're fabricated well enough to simply seat well enough on
their own. Most installations I've seen also have the tank set deeply
enough that the lids are below surface by at least a few inches and so
the ground prevents any air leakage.

If you can't cover them w/ ground (cover w/ plastic first to prevent
dirt entrance), I'd mix up a really thin paste of cement so it
wouldn't have much adhesion power and lay an inch around the lip and
the set the lid on it. Most any flexible material could be used in
the same manner.

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