A sump pump is located in a basement or crawl space prone to flooding or water seepage. These pumps activate automatically when a preset water level is reached in the sump pit. In general, because of how sump pumps function it is not advisable to connect a sump pump to a septic tank.
A sump pump has a single drain line exiting a sump pit. This drain line can be in the form of PVC pipe or something much simpler, such as a section of garden house.
Connecting the Drain
In most instances, the drain line is simply run outside of a house and allowed to drain somewhere on the property. In some cases the drain can be attached directly to the house's drain lines.
In almost all instances, it is a bad idea to add anything to a septic system that will result in additional water entering the system. Your septic system's performance is improved by limiting the water entering the system, so if at all possible, do not attach a sump pump to your septic system.
If the amount of water being removed is minimal, the resulting effects on the septic tank would be minimal. However, in most instances the amount of water being pumped out is higher during heavy rains. This is when the field lines will be the most saturated and be less likely to handle any additional influx of water.
A better alternative would be to plumb the drain line to an area well away from the septic field lines if possible. While you want to remove the water from around your home, you also should limit the amount of drain line as to not overwork the sump pump.