Some products contain organic solvents which contribute to groundwater pollution. If you do not know where your septic tank is located, you can find it by gently tapping a steel rod into the ground starting about 10 feet from the point where the sanitary drain leaves the house. Another method is to wait for a light snowfall. The snow is likely to melt first directly over the septic tank. The drainfield receives septic tank effluent.
Wastewater trickles out of the pipes, through the gravel layer, and into the soil.
The size and type of drainfield depends upon estimated daily wastewater flow and soil conditions. The soil below the drainfield provides the final treatment and disposal of the septic tank effluent. After the effluent has passed into the soil, most of it percolates downward and outward, eventually entering the groundwater. A small percentage is taken up by plants through their roots, or evaporates from the soil. The soil filters effluent as it passes through the pore spaces.