How can I fix and cap my undersized sump?

Question

So, I have an old Sump in my house (built 1960), that currently does not have a functioning pump in it. I plan on replacing the pump and running new exit pipe however, I'm stumped on how to close/cap the sump hole. I mostly want to cap it to reduce radon gasses in my house (we did a reading

The reason is because my sump is only 14.5" across, and 24" deep so all of the standard "sump containers" simply don't fit.

Luckily, groundwater flooding in my neighborhood is very uncommon (the pump I threw out was a 1970's pump that had rusted to no function).

Does anybody know of either a:

A) source of small sump containers?

B) Some way to install a cap on flat concrete?

Answer 1

Buy a steel or aluminum sheet metal plate big enough to cover the hole. You could use a silicon bead under the edge if you really need it to be gas tight, but if you do, when you add a new sump pipe remember to also add a hose to allow air to return into the sump when the pump runs.

Thickness of the plate will depend on the hole location and whether you expect anyone or anything heavy to stand on it.