What is the purpose of the sump pit in my crawlspace?

Question

I am wondering what this sump pit is for in my crawlspace. Water level seems to be stable, haven’t had any overflow.

Should this be cleaned out and covered and sealed?

Answer 1

It appears to be for drainage, and if it does not overflow it was more caution than an actual need, but it's cheaper to do caution up-front than to retrofit a solution after construction. Presumably the lack of pump means it hasn't overflowed (and you state that it does not in your experience.)

You should check your radon levels before deciding what to do here. If you have too much radon, sealing and sucking from the sump pit is a standard way to reduce it. If you don't, there's no need to seal it, though you can cover it if you spend too much time crawling around the crawlspace and worry about falling into it. If the levels are "technically OK but not negligible" you can seal it and run a passive vent pipe up above roof level, which can be converted to an active vent at any time by installing a fan.