Many rural properties rely on oil-fired central heating, in particular in villages where there is no mains gas supply. Although leaks are not a common occurrence, when they occur they can be costly to the householder and can result in environmental pollution.
Oil is toxic and harmful to plants and animals. Spilt or leaking oil can contaminate watercourses and soil, and can pass through the soil and rock to reach groundwater. In Derbyshire Dales there are a large number of private water supplies that rely on the cleanliness of groundwater for their domestic use. On entering a watercourse or groundwater, oil can spread quickly and contaminate a large area in a short space of time.
Oil tanks must be sited at least 10 m from a pond, river, ditch or lake and wherever possible at least 50 m from a borehole or spring. Ideally you should know where any underground pipe work runs and ensure that no above ground activities can puncture it. An Oil Firing Technical Association (OFTEC) technician can advise you on the testing of underground pipe work. A tank should also be sited more than 1.8 m from a non-fire rated building or structure. If you have an internal oil storage tank further fire regulations apply.
The Local Authority, which controls the installation of any new or replacement domestic oil storage tank, will require a Building Notice to show that the work complies with current Building Regulations (unless the work is already covered under a full Building Regulations approval).
Alternatively, the work can be done by a 'competent person'. This is someone who can self-certify their own installation work. OFTEC-qualified and registered installation technicians are regarded as competent persons.
Modern, or newly installed, domestic oil tanks over 2500 m3 must be bunded. A modern bunded tank simply stores the oil in a tank within a tank, so that any leaks to the internal tank are caught within the outer plastic tank. With proper maintenance a modern tank will last for up to 20 years. A new tank storing under 2500 m3 may need to be bunded depending on a site specific risk assessment, taking into account local environmental risks. The District Council would always recommend installing a bunded tank to minimise any pollution risk. Older style tanks are typically made of a single skin and constructed from metal. This means they are more likely to corrode (rust). This can result in water ingress which can ruin any oil stored in the tank and result in leaks where the oil is lost. Furthermore older style metal tanks are not normally bunded so any leak will not be contained.
Most domestic oil tanks have a capacity below 3500 m3 (770 gallons). If you have a tank with a capacity greater than 3500 m3 serving a domestic property you must comply with The Control of Pollution (Oil Storage) (England) Regulations 2001 (as amended).
Further information on preventing and identifying an oil leak, along with how to deal with an oil leak is available in this leaflet [PDF 405KB]. OFTEC provide a useful set of frequently asked questions covering domestic oil tanks.