Can you rule out a problem with the pump? for example is water coming out the discharge pipe?
What has been the normal operating rate for your pump prior to this?
Depending on the configuration of your piping, can you tell where the water is coming in from? It a longshot, I'm wondering if maybe the city water supply pipe broke outside your foundation and the drain tiles are picking it up.
Neighbors having any problems? IMO its impossible for the groundwater table to cause this.