Diesel Storage on Construction Sites: EA Permit Thresholds and Bunding
Construction sites are among the highest-risk environments for fuel spills in the UK. Diesel is used for plant, generators, and heating — often stored in quantities from a few hundred litres in mobile bowsers up to 10,000-litre static tanks. Yet the regulatory framework governing diesel storage on construction sites is frequently misunderstood, with many contractors unaware that they may be operating without the required environmental permits.
This article sets out the Environment Agency's permit thresholds, bunding requirements, and the key legislation that applies to diesel storage on UK construction sites.
The Regulatory Framework
Diesel storage on construction sites is primarily governed by the Environmental Permitting (England and Wales) Regulations 2016 (EPR 2016). These regulations implement a tiered approach to waste and pollution control, with different requirements depending on the volume of fuel stored and the nature of the site.
For construction sites located on or adjacent to agricultural land, the Water Resources (Control of Pollution) (Oil Storage) (England) Regulations 2016 and historically the SSAFO (Control of Pollution) Regulations 2010 — which govern silage, slurry, and agricultural fuel oil storage — may also apply. SSAFO 2010 sets specific standards for oil storage on farms, including minimum bund capacity and construction specifications for containers above 1,500 litres.
EA Permit Thresholds for Diesel Storage
Under EPR 2016, the key threshold for diesel storage on a construction site is 3,000 litres. Below this volume, operations may qualify for a waste exemption — specifically Exemption T29, which covers the storage of waste diesel (i.e., used or contaminated fuel) for transfer. For virgin diesel used as fuel, the COMAH threshold and permit requirements are determined by the total quantity on site at any one time.
Crucially, if a contractor stores more than 3,000 litres of diesel on a construction site, they are likely to require a bespoke environmental permit from the Environment Agency unless they can demonstrate another applicable exemption. Operating without a permit where one is required is a criminal offence under EPR 2016 and can result in an unlimited fine or imprisonment.
| Storage Volume | Regulatory Requirement | Key Legislation |
|---|---|---|
| Under 200 litres | No permit required. Basic bunding good practice recommended. | EA PPG2 guidance |
| 200 – 1,500 litres | No permit required. Bunding strongly advised. PPG compliance expected by EA. | EA PPG2, EPR 2016 |
| 1,500 – 3,000 litres | No permit required but T29 exemption must be registered if waste fuel involved. Full bunding required. | EPR 2016, Reg 5 / Sch 3 |
| Over 3,000 litres | Environmental permit likely required. Contact EA before site set-up. | EPR 2016, Reg 12 |
| Agricultural land (any volume) | SSAFO 2010 may apply. Bund to SSAFO standard required for containers >1,500L. | SSAFO 2010 |
Bunding Requirements: The 110% Rule
Regardless of whether a permit is required, all diesel storage on construction sites should comply with the EA's bunding standard. The minimum bund capacity must be the greater of:
- 110% of the largest single container within the bunded area, or
- 25% of the total storage volume within the bunded area
In practice, the 110% rule almost always produces the larger figure when a single large tank dominates. The bund must be impermeable to diesel, structurally sound, and free of any drains or valves that could allow an uncontrolled release. Drains within bunds must be locked closed and must only be opened manually after checking for contamination.
Mobile Bowser and IBC Bunding
Mobile fuel bowsers present a particular challenge. Where a bowser is in regular transit, it may not require a static bund — but when parked on site overnight or for extended periods, it should be positioned on an impermeable surface with secondary containment. Drip trays rated for the volume of the pump connections and hoses should be in place whenever fuel is being dispensed.
IBCs used for diesel storage must be positioned on compatible bunded spill pallets. Steel IBCs in galvanised spill pallets are generally acceptable for diesel, unlike alkali storage — but the bund must be checked for structural integrity and must not drain to surface water.
Practical Steps for Construction Site Compliance
- Calculate total diesel volume on site before commencing operations
- Register T29 exemption if storing waste/contaminated diesel above threshold
- Contact EA if total storage exceeds 3,000 litres — apply for permit early
- Position tanks and bowsers away from watercourses, drains, and surface water
- Maintain spill kits rated for hydrocarbon spills at all fuelling points
- Train operatives in spill response procedures and emergency contacts
Failure to comply with EA permit requirements on a construction site is not a technicality — it is an offence that routinely results in prosecution, unlimited fines, and reputational damage. Get the permit and bunding right before plant arrives on site.
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