Drainage options
Rural Drainage
The options available for providing non mains drainage normally
involve one of the following solutions.
Cesspool
A cesspool is usually a single chamber, either brick lined (for
older installations) or prefabricated (e.g. fibreglass) with no
outlet to the subsoil. This means that the contents will
require regular removal by a licensed contractor. The
following points should be considered if your house drainage
discharges to a cesspool.
Frequent emptying will be necessary because all the wastewater
is retained in a cesspool.
Emptying records should be retained to demonstrate that the tank
does not discharge to the subsoil.
Do not use a temporary pump to dispose of excess wastewater as
it may cause a nuisance to neighbours.
Septic Tank
A septic tank consists of at least two chambers, a subsoil
drainage field (the infiltration system or soak-away) and
connecting pipe-work. A distribution chamber may be located
between the septic tank and the drainage field to allow sampling of
the effluent and visual inspection of fluid levels.
The raw sewage will undergo settlement and partial treatment in
a septic tank. However, a septic tank will require periodic
emptying to prevent it from filling with solid materials and
overflowing. Lack of maintenance will also result in excess
solids accumulating in the drainage field and causing
blockage. Under poor operating conditions, the quality of the
discharge is likely to deteriorate and may cause a nuisance to
neighbours.
Approved Document H of the Building Regulations 2000 sets out
the design criteria for a septic tank installation and will apply
if you intend to replace an existing drainage system.
Package Treatment Plant
A package treatment plant is a scaled down version of a small
sewage treatment works. It is capable of treating effluent to
a higher standard than a septic tank.
Most septic tanks and package treatment plants will be for
residential use serving less than four people and so the rate of
sewage generation for a typical installation is likely to be less
than one cubic metre per day. The rules applying to consents
for discharging treated effluent will change with effect from April
2010. Further details may be obtained from the Environment
Agency.
Reed Bed
A reed bed or wetland system can improve the quality of effluent
discharged from a septic tank or package treatment plant.
This enhanced level of treatment may be required before a discharge
is permitted into a sensitive or small watercourse, a watercourse
receiving multiple discharges or a drainage field where the
underlying groundwater is vulnerable to pollution.
The Environment Agency is empowered to require householders to
improve the quality of effluent discharged from a septic tank or
package treatment plant and the Council may take action if the
drainage system is inadequate or there is a nuisance to
neighbours.
Further technical advice may be obtained from British Water
publications
This webpage was updated on
1/20/2010