Septic tanks affected by flood waters
Floodwater is highly likely to be contaminated with sewage.
It is therefore important to maintain high standards of hygiene after coming into contact with floodwater. Washing your hands with warm, clean water and soap after being in contact with floodwater is the most effective way of preventing infection. If there is no clean water, use disposable soapy, wet wipes or sanitising gel.
The safe disposal of wastewater is an essential part of protecting your health. If floodwaters have affected your property and you have a septic tank system it may also be affected. Septic tanks take wastewater from your toilet and grey-water from your bathroom, kitchen and laundry.
How will I know if my septic tank system has been affected?
Failed systems are not easy to identify, however some simple indications may include:
- A pungent odour around the tank and soakaway area
- Wastewater overflowing from the tank
- High sludge levels within the septic tank
- Sewage flowing up through the toilet and sinks
Immediate actions while there is general flooding in your area:
Try to stop all non-essential water use and flush toilets as little as possible. Continue to do this until the ground is no longer flooded.
It may be necessary to arrange to have your septic tank emptied more frequently until the ground is no longer flooded. However it is advisable to get advice from your drainage contractor as in some circumstances emptying the tank can cause mud or silt to be drawn into the tank or, in extreme cases, result in it lifting out of the ground.
If your septic tank system becomes flooded:
If your septic tank and/or soakaway becomes covered with water, try not to use the system and avoid contact with any standing water that may contain sewage. Continue to do this until the flooding stops and make arrangements to have your tank emptied if the situation allows. However it is advisable to get advice from your drainage contractor as in some circumstances emptying the tank can cause mud or silt to be drawn into the tank or, in extreme cases, result in it lifting out of the ground
Short-term actions are:
- Keep away from the septic tank drainage area, as standing water/wet ground/ponded water may contain untreated sewage. Avoid doing works until the ground conditions are suitable.
- If you have put caustic or toxic chemicals in your septic tank in the past, and your system backs up into your cellar, basement or drainage field, be especially careful to protect your eyes, skin and lungs from the fumes.
- If sewage has backed up into the house clean the area and disinfect the floor. Use a household bleach based detergent (according to manufacturer’s instructions) to disinfect the area thoroughly.
- Inspect the septic tank system for signs of damage and to determine if removal of silt or debris is required and then take any actions required. An appropriately qualified contractor may be needed to inspect and take action. Only trained specialists should clean or repair septic tanks because tanks may contain dangerous gases.
- For composting toilets or other similar approved systems, contact the manufacturer for specific advice on how flooding or power outages may affect these systems
Keep children and pets away from floodwater affected areas.