DNREC advises septic system owners on flooding impacts from Hurricane Sandy
With Hurricane Sandy's impacts expected to cause extensive flooding along Delaware's coastline and some inland areas, the Department of Natural Resources and Environmental Control advises septic system owners on how to manage the care of their systems during the storm and in its aftermath.
Should I pump my septic tank?
No. Only after floodwaters have receded should a septic tank be pumped. Under severe conditions tanks can float out of the ground when pumped causing damage to the inlet and outlet pipes. Metal tanks and cesspools can collapse from the water pressure against the sides of the tanks during pumping. The best solution is to drastically reduce your water use and plug all drains in the basement until floodwaters recede.
What do I do with my septic system after the floodwaters have receded?
Do not use the septic system until the floodwaters have receded below the water level around the house.
Do not open the septic tank for pumping while the soil is still saturated. Mud and silt may enter the tank and end up in the drainfield.
Contact a Class F liquid waste hauler to have your septic tank professionally inspected and pumped as soon as possible after the flood. Pump both the septic tank and the dosing chamber if applicable. While most septic tanks are not damaged by flooding, any silt or debris that has entered the tank needs to be removed to avoid clogging the drainfield area. Contact the Ground Water Discharges Section for a list of Class F licensed liquid waste haulers. Homeowners should never clean or repair a septic tank due to dangerous gases that can build up in septic tanks.
If sewage has backed up into the basement or inside the dwelling, clean the area and disinfect the floor. Use a chlorine solution of a half cup of chlorine bleach to each gallon of water to disinfect the area thoroughly. Avoid dumping any water back into the sink or toilet. Wait until you are certain a backup will not happen again.
Flooding of the septic tank may have lifted the layer of fats and greases found inside septic tanks. Some of this scum may have floated and/or partially plugged the outlet tee. If the septic system backs up into the house, check the outlet baffle on the septic tank.
Do not drive or operate equipment over the drainfield area. Wet soil is especially susceptible to compaction which can lead to system failure.
Be sure the septic tank’s manhole cover is secure and that the inspection ports have not been blocked or damaged.
Also be mindful that floodwaters can become contaminated from both wastewater and neighbors'. Use caution and avoid contact as much as possible.
For more advice and assistance in handling septic systems after Hurricane Sandy, please contact the DNREC Division of Water’s Ground Water Discharges Section. For Sussex County residents, call 302-856-4561.