I had a sump pump replaced in my 37 year old house. It is an above ground sump pump and stands on a pedestal in the sump pump hole. The cover is two half circles about 2 2 1/2 inches thick (Concrete) that fit together to form (circle) the cover. The new sump pump is too low for the cover to fit. Is it all right to put bricks under the pedestal in the hole to raise the whole unit up so the cover will fit or will this reduce the sump pump's effectiveness? I want the hole covered because we have a radon problem in our city. Thank you. If it is not possible to do it this way, any suggestions?

Yes, you can raise the pump up with out affecting its operation. You will have a couple more inches of water in the sump crock when the pumps shuts off but that does not matter. The pump does not pump all of the water out anyway.

If you are concerned with radon this fix is worthless. Your can test for radon but if you have it the basement needs extensive work to make it air/water tight and a mitigation system installed. Recommended Residential Radon Mitigation Standard of Practice | Publications | Radon | Indoor Air Quality | Air | US EPA