Septic tanks have widely been used in rural areas of the UK since the early 1900’s for areas where ‘mains drainage’ is not available or the cost of connection is prohibitive.
The main purpose of a septic tank is to separate the receiving waste water and allow the solid material to settle and undergo a process known as ‘anaerobic digestion’. This has the effect of reducing the sludge volume and therefore the frequency of the septic tank requiring emptying. The resulting effluent is disposed of to an underground soakaway.
Although many septic tank systems work effectively, there are various septic tank problems that homeowners can experience with these systems, including:
- Flooding of the drains;
- Pollution in nearby watercourses;
- Structural problems;
- Odour nuisances;
- Visual impact on the garden.
Flooding of the drains
There are many reasons which may cause a septic tank to flood and these can range from something as simple as an outlet ‘dip pipe’ being blocked to more serious problems involving the receiving soakaway system. If a soakaway fails and prevents the effluent from percolating through the ground this will result in the soakaway, septic tank and the foul drainage pipe work surcharging. Click here for further information on a septic tank flooding.
Pollution in nearby watercourses
Septic tanks are not permitted to discharge into any watercourses whether it be a ditch, stream or river, regardless of the age of the discharge. In situations where a septic tank is discharging to a watercourse it would be necessary for the discharge to be stopped, or for the sewage to be ‘treated’ by means of a septic tank conversion unit or packaged sewage treatment plant. Click here regarding the rules on septic tank discharges.
Structural problems
Septic tanks can suffer from structural problems in relation to both the main body of the tank and the internal components. In situations where the exterior of the tank is exposed to substantial ground movement the tank can implode or crack. Structural damage can also occur to the baffles contained within prefabricated tanks and the inlet and outlet ‘dip pipes on traditionally built tanks. Click here for further information on this subject.
Odour nuisance
During the ‘anaerobic digestion’ process within a septic tank methane, hydrogen sulphide and other gases are produced and these gases can in some cases cause a serious odour nuisance. In view of this, it is essential that septic tanks are correctly vented to allow the noxious gases to escape into the atmosphere. Unfortunately, there is no way of preventing these gases from occurring within a septic tank.
Visual impact on the garden
In many instances older septic tanks can have a large concrete cover slab. Depending on the location of the septic tank within the garden setting, this can sometimes be obtrusive and spoil the appearance of a garden.