Buying a property with a septic tank/plant

If you are planning to buy a property which is not connected to the public sewer or install a new system then you should be aware of the relevant regulations. It is an offence to discharge sewage into the ground or surface waters without an environmental permit. That said most discharges of domestic sewage will be exempt on the basis certain requirements can be met.
If your house is not connected to the public sewer, your sewage will go to one of the following:
• a septic tank – an underground tank where liquid flows out and soaks through the ground;
• a small sewage treatment plant (also known as a package treatment plant) – a part-mechanical system that treats the liquid so it’s clean enough to go into a river or stream;
• a cesspool (also called a cesspit) – a sealed tank that collects the sewage;
• a non standard system
An “operator” of such system must adhere to certain rules and requirements.
You will be an “operator” if you own the system or use a shared system (each property is an operator and the obligations are shared) or you have a written agreement stating you are responsible (such as a tenancy). An operator must meet the “General Binding Rules” (“the Rules”) which were first introduced in January 2015.  If the system does not meet the Rules you must apply for a permit.
In order to comply with the Rules the sewage must be:-
• domestic in nature, for example from a toilet or bathroom;
• must not cause pollution.
As the Rules came into force on 1 January 2015 if your system was installed and discharging before 31 December 2014 you have an ‘existing discharge’. If your system was installed and discharging on or after 1 January 2015 you have a ‘new discharge’.
All new discharges require planning permission and building regulations approval and if the system was installed following this date and the relevant permissions were not sought retrospective consent should be obtained.
There are other rules depending on whether you’re releasing this sewage:
• to the ground, eg in your back garden;
• to a surface water, eg a river or stream;
• discharges in a groundwater source protection zone 1;
A groundwater source protection zone 1 can be either:-
• an area around a commercial water supply (used for drinking water or food production) shown on the map of protected zones – check if your discharge is in the inner zone (zone 1) or ask the Environment Agency;
• any area within 50 metres of a private water supply for human consumption – ask your neighbours if they have one and if so how far their spring, well or borehole is from your drainage field
You must apply for a permit if you have an existing discharge or are planning to start a new discharge to the ground in a protection zone 1. A permit will include additional conditions to the Rules.
The Environment Agency is likely to grant the permit if there is no evidence of pollution or the risk of pollution is an acceptable one. If the pollution is at an unacceptable level the Environment Agency will ask you to make changes to your system and may issue a permit with improvement conditions.
The Environment Agency will regularly check the quality of surface and ground water and compliance with any permits. Permits may be reviewed or revoked if pollution is found.
A permit will also be required if the discharge point is in or near a designated sensitive area which includes ancient woodland, special areas of conservation, special protection areas, Ramsar sites and biological sites of special scientific interest.
You can make and enquiry to the Environment Agency and find out whether the above applies to your property.
A cesspit/pool is a sealed tank and owners do not need to comply with the Rules or apply for an environmental permit. However it’s important to note, the cesspit must be maintained and emptied regularly by a registered waste carrier and planning permission and building regulation approval should be obtained for installation.
As well as the above it is also necessary to consider:-
(a) if the tank/plant exclusively serves the property;
(b) if it is wholly within the boundaries of the property – if not are there adequate rights to use the tank and enter the adjoining land for maintenance etc?
(c) the practical arrangements in respect of emptying the tank and maintenance, particularly relevant if shared with other properties;
(d) consider when the system was last serviced and whether any recommended works have been carried out satisfactorily.
If you need more information regarding this, please contact our Residential Conveyancing Team on 0800 088 6004