Pre-winter oil tank check: Prevent pollution and save money, says NRW

Natural Resources Wales (NRW) is calling on owners of domestic oil tanks to carry out regular maintenance checks to avoid environmental damage from fuel spillages this winter.

While homeowners who store oil have a legal responsibility to make sure their storage tanks do not cause pollution, a large number of incidents resulting from tank leaks still happen each year.             

Leaked fuel badly damages the environment – it can kill plants, harm wildlife, pollute rivers and contaminate drinking water.

Fuel loss is an expensive problem for homeowners too; leaving them to foot the bill of replacing oil and potentially having to pay thousands of pounds to clean up an oil spill.

Huw Jones, Environment Team Leader with NRW:
“Before we start to see frosty weather, it is important that homeowners check tanks and their pipework to make sure they are well maintained.
“When water enters an oil tank, it accumulates below the oil at the base of the tank. This may not immediately cause a problem, but once the volume of water increases it can also enter the pipework.
“Water in a steel tank can lead to corrosion and in very cold weather it can expand and freeze. This can rupture pipes and fittings, leading to potential fuel loss and unfortunately, in many cases, a significant environmental incident.”

One sign of a leak is if the volume of oil you use suddenly increases. Getting advice from a qualified oil heating professional is essential to address any problems.

Steps to help prevent an oil spill include safe tank filling by ensuring your delivery driver uses the tank fill point and there is space for the oil in your tank. It is also important to check the tank base or supports for cracking or subsidence and to check all visible pipework, valves and filters for damage and signs of leaks.

Any secondary containment (tank bunds) should also be checked for liquid or rubbish, and to ensure drip trays for remote fill pipes are clear and do not have any oil, water, leaves or rubbish in them.

Householders should also check if an oil spill is covered by their home insurance, including the clean-up of oil on your property, neighbouring properties, and seepage into the ground or watercourses.

For more information you can visit Natural Resources Wales / Check your household oil tank for leaks

Report all suspected pollution and other environmental incidents to NRW via the 24-hour incident hotline 0300 065 3000 or email