Cesspools
Cesspools
If you require a temporary sewage disposal system whilst you are preparing a permanent solution, a cesspool might be a suitable method.
The Environment Agency donít encourage the use of cesspools and you might need permission from the local authority Environmental Health Officer
In Scotland, the Building Standards do not permit the use of cesspools. The minimum capacity of a cesspool is set in guidance supporting the Building Regulations. You should check with your supplier to make sure the unit you buy fully complies with legal requirements.
A cesspool is a covered watertight tank used for storing sewage. It has no outlet and relies on road transport for the removal of raw sewage. It is the least sustainable option for sewage disposal. You should consider a cesspool as a temporary measure pending a more satisfactory solution, such as the provision of mains drainage. A cesspool requires regular emptying and must not be allowed to overflow. The EA recommend you install a level warning device to indicate when it is nearly full. You should check that whoever empties your cesspool is registered with us to carry waste. You can use your local authority or a private contractor as an emptying service (you should check, as emptying services may be non-existent or expensive in your area) The average household of three people will produce 9,000 litres of sewage in about two weeks, the capacity of a typical emptying tanker.
You should site a cesspool where it cannot affect surface or ground waters and cannot cause a nuisance to nearby residential properties. The Building Regulations set minimum distances from certain features and you should consult your local authority to ensure you locate your plant appropriately.
Additional treatment systems for further improving effluents before discharge to a watercourse (effluent polishing systems)
Reed Bed Systems
A reed-bed or wetland system should improve the quality of effluent discharges from septic tanks, a settlement tank or package sewage treatment plants. This enhanced level of treatment might be required before a discharge is allowed into a sensitive or small watercourse, a watercourse that receives many discharges, or a drainage field where groundwater is vulnerable. Our consent is required for a discharge from a reed-bed to a watercourse or drainage field. In some cases the addition of a reed bed is a legal requirement.
a) Reed-beds are specially designed and constructed plots with a granular medium and an impermeable base which can be used to improve effluent quality. They have the advantage of having no moving parts and require less maintenance than package treatment plants. Reed-beds rely on the ability of certain plants to absorb and transport oxygen through their stem system to the root zone, where it can be taken up by the organic material present in the sewage and so purify the effluent.
b) Before you install a reed-bed, you should consult us to discuss whether it will be a satisfactory means of treating the effluent given the local circumstances. Any reed-bed should be properly designed, constructed and
maintained.
Partial or Seasonal Drainage Field
This is a hybrid option incorporating an overflow to a watercourse from the highest point of the drainage field. They can provide a disposal solution for sites where there is a high water table in winter and low surface water flows in summer.
Disinfection
Disinfection can be provided for effluent discharges into watercourses that enter or lead to bathing, shellfish or
recreational waters. The disinfection process kills off many of the bacteria present in the effluent and prevents the development of infections and ill health in those using the bathing or recreational waters. The disinfection can be achieved by several methods but for each of them the effluent quality has to be quite good for the treatment to be effective. It will not work on septic tank effluent without additional treatment. The equipment manufacturer should state the capability of their equipment.
Filtration
There are several filtration systems on the market that can filter effluent from package sewage treatment plants and polish the effluent to a better quality. These include sand filters, drum filters, membrane filters and microfilters.
They take up a smaller area of land than some other options but they require ongoing maintenance and usually need a power supply.
Stabilisation ponds
Stabilisation ponds allow the effluent to be retained and improved for a while before discharge to a watercourse or soakaway. They are only suitable for effluents that have already been treated to a high level as any significant residual organic matter can make the pond smell foul. They can provide an attractive natural habitat for plants and animals. However, high nutrient levels usually mean they are unsuitable for fish.
Gravel Beds
Gravel beds spread effluent evenly across a bed of gravel. The effluent is further treated as it comes in contact with micro-organisms living on the gravel surface. The effluent quality should be quite good before it is treated this way or the gravel bed can block and stop working. Gravel beds sometimes require a power supply. They are often able to cope with uneven flows.
Drainage Mounds
Drainage mounds are constructed from layers of different material which the effluent passes through and the micro-organisms within the layers breaks down any residual organic matter