For anyone who relies on suppliers of heating oil shropshire to keep their home or business warm, the oil tank is the most important piece of equipment on the property, and yet it is probably the least thought about. Tucked away outside the house, often obscured by fencing or planting, it sits there year after year quietly doing its job until, one day, it does not. A leaking or failed oil tank is not just a heating problem. It is a potential environmental incident, a regulatory issue and, depending on the circumstances, a very expensive one.
Understanding your oil tank, how to look after it, when it needs replacing and what the regulations require of you, is one of the most straightforward and cost-effective things you can do to protect your property and your peace of mind. This guide covers everything you need to know.
Types of Oil Tank
The first thing to understand is that not all heating oil tanks are the same, and the differences between them matter both for performance and for regulatory compliance.
Single skin plastic tanks. These are the most common type found in domestic properties and were the standard installation for many years. They consist of a single layer of plastic, typically polyethylene, which provides the fuel containment. They are lightweight, relatively inexpensive and resistant to corrosion. However, they provide no secondary containment, meaning that if the tank develops a leak or is accidentally damaged, the fuel can escape freely into the surrounding ground.
Bunded plastic tanks. A bunded tank consists of an inner tank, which holds the fuel, within an outer tank, which acts as secondary containment. If the inner tank leaks or is damaged, the outer bund retains the fuel, preventing it from reaching the ground. Bunded tanks are now the required standard for most new installations, particularly in locations close to watercourses, in areas of high groundwater sensitivity, or where the tank capacity exceeds certain thresholds. They are considerably safer from an environmental protection perspective and are strongly recommended even in locations where they are not strictly required by regulation.
Steel tanks. Steel tanks were commonly installed before the widespread availability of plastic alternatives and many remain in service, particularly on farms and in commercial settings. They are robust and can be made in large capacities, but they are susceptible to corrosion over time, both externally from weathering and internally from water condensation within the tank. Older steel tanks that are approaching the end of their serviceable life should be carefully monitored and replaced before they fail.
Slimline and horizontal tanks. Both plastic and bunded tanks are available in a range of configurations to suit different installation locations. Slimline tanks are narrower than standard tanks, making them suitable for locations where space is restricted. Horizontal tanks are an alternative to the more common vertical design and can be useful in locations with limited overhead clearance.
Oil Storage Regulations: What You Need to Know
Oil storage in the UK is subject to regulation, and understanding what is required of you is important both to ensure compliance and to protect yourself from liability if something goes wrong.
In England, the Control of Pollution (Oil Storage) Regulations 2001 apply to any above-ground oil storage container of 200 litres or more used for non-domestic purposes. The regulations specify requirements for secondary containment, labelling, condition and the positioning of tanks in relation to watercourses and drains. There is currently no equivalent statutory regulation for domestic oil storage in England, but there are published guidelines from the Environment Agency that set out best practice and that form the basis on which liability is assessed in the event of a pollution incident.
In Wales, the Water Resources (Control of Pollution) (Silage, Slurry and Agricultural Fuel Oil) (Wales) Regulations 2010 and the Environmental Permitting Regulations set out requirements for agricultural fuel storage. For domestic users in Wales, as in England, there is no specific statutory regulation, but the best practice guidelines are broadly the same.
The practical effect of all of this is that any oil tank installed today, whether domestic or commercial, should meet the current best practice standards, which means bunded containment in most cases, correct positioning, appropriate labelling and regular inspection. If your existing tank does not meet these standards, you are not necessarily required to upgrade it immediately, but you carry greater environmental and financial liability if it fails and causes a pollution incident.
If you are uncertain about the regulatory status of your installation, a conversation with your oil supplier or with an oil tank installer will quickly clarify what is required.
How Long Does an Oil Tank Last?
Plastic tanks have a typical working life of around 20 to 30 years, depending on the quality of the original installation, the conditions they are exposed to and how well they are maintained. However, this is a guide rather than a guarantee. Tanks can develop problems sooner, particularly if they have been subjected to physical damage, installed on an unstable base, or exposed to conditions that accelerate degradation.
Steel tanks have a more variable lifespan depending on the quality of the steel, the conditions of use and the level of maintenance they have received. Many commercial steel tanks installed in the 1980s and 1990s are now approaching or past the end of their recommended service life and should be assessed carefully.
The key point is that tanks do not fail all at once. Deterioration is gradual, and a tank that is showing early signs of wear can often be replaced in a planned and orderly way before it develops a serious problem. The alternative, waiting until a catastrophic failure occurs, invariably costs more and causes far greater disruption.
Signs That Your Tank Needs Attention
Regular inspection of your oil tank is one of the most important things you can do as a heating oil user. The following signs should be investigated promptly.
Visible cracks or stress marks. Even hairline cracks in the tank body are a warning sign that warrants professional assessment. On a plastic tank, white stress marks or crazing in the surface of the plastic indicate material degradation that may be progressing towards failure.
Staining or discolouration around the base. Oily staining on the ground around the tank, or discolouration of the tank itself near the base or at any joint or fitting, may indicate a slow leak. This needs to be investigated and remedied promptly.
Rust or corrosion on steel tanks. Surface rust on the exterior of a steel tank is not necessarily critical, but deeper corrosion, particularly around welds, fittings or at the base of the tank where water tends to accumulate, is a serious concern.
Deterioration of the bunded area. On a bunded tank, check the condition of the outer containment shell as well as the inner tank. If the bund is cracked or damaged, it will not provide the secondary containment it is designed for.
Unstable base. The ground beneath an oil tank can shift over time, particularly in wet conditions or where the base was not properly constructed in the first place. An unlevel or unstable tank places additional stress on fittings and pipework and may indicate that the base needs to be assessed and remediated.
Age. If your tank is more than 20 years old, it is worth having it formally assessed by a qualified installer even if no obvious problems are apparent. A professional assessment will give you an informed view of the tank’s condition and remaining service life.
What to Do If You Suspect a Leak
If you suspect your oil tank is leaking, act immediately. Even a slow leak from a domestic tank can release a significant quantity of fuel into the ground in a short time, causing environmental contamination that is expensive to remediate and for which the property owner is liable.
Turn off the supply valve from the tank to the boiler. This prevents further fuel from reaching the leak point if the problem is downstream of the valve. Contact your oil supplier and, if the leak is significant or if fuel has reached a drain or watercourse, contact the Environment Agency in England (via their incident hotline on 0800 80 70 60) or Natural Resources Wales in Wales. Concealing or ignoring a known oil leak is not an option: the pollution and liability consequences are serious and worsen with time.
Do not attempt to repair a leaking tank yourself using sealants or patches. These are temporary measures at best and do not address the underlying failure. A proper repair or replacement is required.
Tank Replacement: What the Process Involves
When the time comes to replace an oil tank, the process is more involved than simply swapping one tank for another, and it is worth understanding what it entails so you can plan appropriately.
Fuel uplift. Before the old tank can be removed, any remaining fuel in it needs to be removed. Your oil supplier can arrange for the fuel to be uplifted, either returning it to you once the new tank is installed or crediting it to your account.
Tank removal and disposal. The old tank needs to be removed from site. Tanks that have contained fuel are classified as waste containers and need to be disposed of responsibly through a licensed waste contractor.
Base assessment and preparation. The base on which the new tank will sit needs to be structurally sound, level and of sufficient size and strength to support the full weight of the loaded tank. If the existing base is inadequate, it will need to be replaced or improved. A concrete or compressed hardcore base is standard for most domestic installations.
New tank installation. The new tank is installed on the prepared base, connected to the supply pipework and boiler, and the system is tested for leaks before being put back into service.
Regulatory compliance. The installation should be carried out by a competent professional who is familiar with the current regulations and best practice guidance for oil storage. The positioning of the tank relative to the house, any watercourses, drains and property boundaries will all be checked as part of the installation.
Most reputable oil tank installers and fuel suppliers can coordinate the entire process, from fuel uplift through to new tank installation and commissioning, making the experience as straightforward as possible for the property owner.
Choosing the Right Tank for Your Needs
When selecting a replacement tank, the key decisions are capacity, type and positioning.
Capacity should be chosen to reflect your annual consumption and the frequency with which you want to order. A larger tank means you can order less frequently, take advantage of lower summer prices by filling up when costs are lower, and reduce the risk of running out. Most domestic properties are well served by a tank of 1,000 to 2,500 litres, but higher-consumption properties or those that want to order just once or twice a year may benefit from a larger capacity.
Bunded vs single skin. As noted above, a bunded tank is the right choice for any new installation from both a regulatory and an environmental protection perspective. The additional cost over a single skin tank is modest relative to the protection it provides.
Positioning. The tank should be positioned on a stable, level base, at a suitable distance from the property, boundaries and any drains or watercourses as required by the current guidelines. It should be accessible to the delivery tanker without requiring an excessively long hose run and should be in a location where the fill point and gauge are easily accessible.
A knowledgeable supplier can advise on all of these decisions based on your specific property and circumstances, ensuring that your new tank meets your needs for decades to come.