Slow drains or sewage backing up into the house:
The cause could be a blockage in the plumbing line to the septic tank, blockage to inlet and outlet tees within the septic tank or a clogged filter if present. If the problem only occurs during rainy weather, the problem could be related to surface water drainage or water standing on top of the absorption field area. If the septic tank system is old, the absorption line may be clogged. If the system has a pump, pump failure could be the cause.
Surfacing of septic tank effluent on the ground surface:
The cause may be related to a poor soil absorption rate, soil clogging in the absorption line,
or water usage. If the problem is noticeable only after rainy weather, the problem could be
related to surface water drainage or a high seasonal groundwater table.
Smell of sewage odor:
The cause of sewage odors may be natural gases that occur in the septic tank that are vented
from the plumbing system through the roof of the house. Odors may be noticeable in the area of
the vent pipe. Odors near the septic tank could indicate a cracked inlet or outlet plumbing pipe. Odors in the absorption field area could indicate a surfacing of wastewater effluent.

Any repair work performed on an on site sewage management system requires a repair permit from the county health department. The county environmental health specialist can assist homeowners with an evaluation of the system to determine repair options. A certified septic tank contractor should perform any repair work.