Septic Tank Inspection for Housebuyers

Arranging a septic tank system and soakaway drain field inspection is perhaps the most important thing that you must do when purchasing a rural property.

The cost of replacing the sewage system can amount to thousands of pounds and the sewage system does not form part of the normal house survey. Septic tanks can become dangerous over time and inspections are essentail. 

The major points of a good septic tank system inspection include: 

1.    Making sure that the septic tank system complies with the Environment Agency General Binding Rules.

2.    Checking that the design and size of the septic tank is suitable for the size of your family.

3.    Checking the tank for water after it has been fully pumped of all its prior contents. The surveyor will require that you shut off the water in your house. Water flowing into the tank from your house when you have no taps or appliances being used indicates that there is a problem with your drains leaking ground water into them. If there is water flowing in from the drain field outlets, you have a problem with the drain field; further inspection will be required.

4.    The septic tank should be inspected for signs of ‘backing-up’ from the drain field soakaway in the past.

5.    The inspection should check that no rainwater is entering the system from the gutters and drains.

6.    A good and thorough check of both the baffles and the ‘T’ pipes of your system. Baffles are installed on the tank during the building of the tank in the factory and allow sewage effluent to flow between the chambers. Concrete baffles must be checked for cracks cause by external stress, as this could create a major problem for your system down the road. T pipes are the fittings on the inlet and outlet of the tank. They can be plastic or salt-glazed pipes and they must be checked for damage, strength and stability also.

7.    Every attempt should be made to find the discharge point or soakaway area as septic tanks are not allowed to discharge into ditches, streams or any other watercourse.

8.    An assessment should be made of the overall condition of the tank, the risers and the lids and covers. The cover inspection is particularly important as septic tank gases contain Hydrogen Sulphide which turns into Sulphuric Acid in contact with air.  This corrodes both metal and concrete over time and the covers become very unsafe. Hundreds of people die in septic tanks each year due to the collapse of septic tank and cesspool covers. NEVER stand on the cover of a septic tank - it may be the last step you ever take!

9.    The system should be checked to make sure that certain appliances do NOT discharge into the septic tank.

A septic system hangs in a delicate balance between input, processing in the tank, and output being absorbed into the drain field. Without a proper inspection, you are leaving this continuity of the balance up to chance and risking a great amount of potential expense as a result. Fixing a problem with the septic tank can be expensive, but it is a lot better to find out before you buy the property than afterwards.

Septic tank inspections are essential if you want to avoid problems when you move in.

Atlternatively, we have written an article on How to do a DIY septic tank inspection survey.