There are three possibilities:
1. Assuming that this is a sump pump well (not ejector pump) you’re asking about.
If the drain tile (that's how they call pipes that run under your house, collect ground water, and discharge it into the sump pump well) hasn’t been sealed around the penetration of the basin’s wall (they rarely are sealed properly) it will leak ground water into the basin.
This is normal and it shouldn’t cause any problems unless there are debris, mud, gravel, sand, and other contaminants pouring into the basin. Sump pump
performance / operation could be compromised or pump’s impeller (and motor) permanently damaged.
If the sump pump is operating properly and there’s no debris accumulation inside the basin there’s nothing to worry about. However, you should monitor sump pump basin’s bottom periodically.
2. However, if this pump acts as an ejector pump for the washing machine and / or your bathroom, laundry, kitchen, etc., the PVC pipe should be sealed around the basin’s side wall penetration so none of the sewer / bacteria contaminated water discharging from the house’s plumbing fixtures mixes with the groundwater. To determine what the role of your pump is, flush the toilets and open the faucets to see if there’s any water discharging from the PVC pipe into the basin.
3. This basin and the pump are used for both purposes at the same time, which is not a proper installation and should be corrected by a plumber.