Cause B.3. High water table in spring (rainfall). Septic system operation can become sluggish and even fail in the spring, because a seasonal high water table may saturate the soil around the trenches. Homesites and absorption fields in flat areas having poor surface drainage are especially susceptible. If this describes your situation, about the only thing you can do is to use subsurface tile drainage to lower the water table. The drainage tile must discharge to a surface ditch or to a larger tile drainage system.

If located on a sloping site, installation of drain tile upslope from the absorption field should be very effective in lowering the water table. Place the tile at least 25 feet away from the filter field and at least as deep as the bottom of the trench. Home water conservation devices and practices may also be needed to make it through wet springtimes and prolonged rainfall periods.