Bunds for oil and chemical storage on construction sites
Bunded areas to comply with oil storage regulations and for safe chemical storage
A bund is a structure that storage tanks or barrels can be stored inside. It is designed to prevent oil, fuel or chemicals from escaping into the environment if the storage tank or barrels leak or burst.
What you must do
Bunds or secondary containment systems must meet certain requirements, as specified in General Binding Rule (GBR) 28 in Scotland and the Oil Storage Regulations in Northern Ireland. The requirements include:
Location
Identify a location on site where you can set up a storage compound for oil, fuel and chemicals. Ideally, the compound should remain in the same place for the duration of your works. It should be as far away as possible from surface waters, groundwater and surface water drains.
Plan how the storage compound will be removed at the end of the contract.
Identify the types of waste that will be present and where you can dispose of them.
Capacity
A bund should be able to contain 110% of the volume of the largest container stored within it.
For drum storage, the bund capacity of 25% of the maximum volume of material stored is sufficient.
A notice close to the bund should display the maximum number of barrels and containers that can be stored at any one time.
Maintenance
Your environmental regulator can serve you with an 'anti pollution works notice if your site causes, or is at risk of causing water pollution. This notice will require you to clean up any pollution and to take action to prevent any further pollution.
The volume of rainwater within any bunded area should never exceed 5% of the total volume of the bund. Accumulated rainwater and other liquid in the base of the bund will reduce its capacity and may need to be disposed of as hazardous/special waste.
If possible, put a roof over the bund and cover the sides that receive the most severe weather. By reducing the amount of contaminated rainwater in the bund that you must dispose of, you could save money.
Nominate someone to check regularly that the bund is intact and not leaking.
Evidence of leaks can include discolouration of unrendered block or concrete bund walls or an oily sheen on any water standing on the ground close to the bund. If the bund is leaking, you should take immediate action to prevent land contamination and pollution of surface waters and groundwater. Your environmental regulator will be able to advise you on what action you should take.
Contact your environmental regulator
Where appropriate, you could paint concrete bunds or refuelling areas with epoxy-type paint to prevent fuel and oil drips from soaking in.
When you break out the concrete at the end of the project, it may not need to be disposed of as hazardous/special waste as it is less likely to contain soaked-in oil or diesel. Look at the broken out concrete to see if it is discoloured, smell it to see if it smells of oil, diesel or petrol. If you are unsure, have samples laboratory tested. You should also make sure that your waste haulage contractor agrees with your classification of the material.
Associated equipment
All hoses, valves, trigger guns, funnels and other associated equipment should be kept within the bunded area to prevent land around the bund from being contaminated.
Any trigger guns present should be fitted with an automatic cut off. This will help prevent spills of fuel onto the ground from equipment or containers being overfilled.
Deliveries
Supervise deliveries of raw materials or fuels to your site and clearly label tanks with their contents and storage capacity; this will reduce the risk of overfill and spillage.
Records
Keeping the following records may be useful to you:
- when the bund was last inspected
- the rainwater level – the more rainwater present within the bund, the lower its capacity for containing spills
- how frequently rainwater is removed – this overlaps with your duty of care for the disposal of contaminated rainwater
- any maintenance work undertaken on the bund.
Further information
- GPP 2 Above ground oil storage tanks (Adobe PDF - 276KB)
- GPP 21 Pollution incident response planning (Adobe PDF – 318KB)