What Is Bulk Fuel Storage? Definition, Tanks & UK Compliance

Bulk fuel storage means keeping significant volumes of liquid fuel on site in engineered tanks so you can refuel plant, vehicles or generators without relying on forecourts or regular deliveries. It typically starts at around 200 litres and scales to tens of thousands. Common products include diesel, gas oil, petrol, kerosene and renewable blends, in above‑ or below‑ground systems with containment and monitoring.

This guide covers typical volumes and fuels, choosing between above‑ground and underground tanks, and how secondary containment works. We outline tank materials, key components, who uses bulk storage, benefits and risks. You’ll also get a plain‑English overview of UK compliance, siting, environmental and safety controls, fuel quality, deliveries, permits, training, and sizing a compliant system.

Typical volumes and fuels that count as bulk

In practice, anything from 200 litres upward is treated as bulk fuel storage, with end‑user tanks commonly ranging from a few thousand litres to 110,000 L or more, depending on usage and delivery frequency. Typical fuels include diesel (DERV), gas oil (red diesel), petrol, and kerosene, plus renewable options such as biodiesel blends (e.g., B5–B20) where fleets want tighter control over quality and supply.

Above-ground vs underground: choosing a location

Choosing above‑ground or underground bulk fuel storage shapes cost, inspection and risk. ASTs are quicker to install and maintain, with easier leak monitoring, but are exposed to weather and often need pump‑assisted deliveries. USTs save space, stabilise temperatures and allow gravity‑fed deliveries, with lower fire/explosion exposure; however they’re harder to access for repairs and leaks aren’t visible.

Single-wall, double-wall and bunded: how secondary containment works

Secondary containment is the safety net that stops product escaping the primary tank and reaching soil or water. In bulk fuel storage, a single‑wall tank must sit within a separate bund (for example a dike, curb or pit) to capture leaks and spills. A double‑wall, or “bunded”, tank integrates this protection: the inner tank holds fuel, the outer wall forms the bund, and the interstitial space between them can be monitored for leaks. In the UK, bulk fuel tanks are required to be bunded, improving environmental security and theft resistance while simplifying compliance.

Tank materials and construction

Bulk fuel tanks are typically fabricated from carbon steel or stainless steel for strength and impact resistance (common for above‑ground tanks), or from fibreglass‑reinforced plastic (FRP) and sometimes concrete for underground installations. Double‑wall (bunded) tanks comprise an inner tank and an outer wall with an interstitial space that can be leak‑monitored; some designs incorporate concrete in this space for added protection. Robust builds add practical features such as certified lifting lugs, and lockable cabinets that house pumps and dispensing equipment.

Key components of a bulk fuel system

A bulk fuel ‘tank’ is a complete system for storing, measuring and dispensing product safely. Beyond the vessel, the right components drive reliability, compliance and fuel quality. Core elements typically include:

Fuel tank: sized to demand.
Pump: duty‑rated transfer.
Dispenser, hose and nozzle: controlled issue; optional filtration.
Tank gauging/leak detection: levels and interstitial monitoring.
Fuel management system: access control and transaction logs.

Who uses bulk fuel storage and when it makes sense

Bulk fuel storage is widely adopted by fleet operators, construction and heavy machinery sites, forestry and agricultural businesses, industrial facilities, and locations running generators for prime or standby power. It makes sense when fuel use is high and frequent, sites are busy or remote, deliveries are limited, or you want to cut costs by buying in bulk, tighten control over dispensing, and maintain supply resilience during disruptions.

Benefits, risks and common pitfalls to avoid

Done right, bulk fuel storage boosts efficiency and uptime, lowers per‑litre costs through bulk buying, secures supply during disruptions and cuts site traffic. Bunded, leak‑monitored tanks aid compliance, and centralised refuelling reduces wear. Main risks are spills, non‑compliance, fuel degradation and theft.

Inadequate containment: single‑wall tanks without a compliant bund.
Poor quality control: no testing/filtration, inviting water or diesel bug.
Weak access control: unmanaged dispensing, theft and wastage.
Neglected maintenance: gauges, hoses and pumps left unchecked.

UK regulations and standards you must follow

In the UK, bulk fuel storage is controlled under DSEAR (Dangerous Substances and Explosive Atmospheres Regulations). For bulk fuel tanks, bunding is a legal requirement, with DSEAR regulation 6(4)(e) cited as the basis for bunded tanks in practice. The HSE’s guidance HSG176, The storage of flammable liquids in tanks, applies to above‑ and below‑ground fixed bulk tanks and sets out good practice for design, siting, operation, inspection and emergency arrangements. Modern double‑wall (bunded) designs and leak‑monitored interstitial spaces support environmental compliance by containing spills and aiding early detection.

Use bunded tanks: Meet DSEAR expectations for secondary containment.
Follow HSG176: Apply HSE guidance on design, siting, operation and inspection.
Monitor for leaks: Interstitial monitoring and regular checks improve assurance.
Control access and security: Manage who dispenses fuel to reduce loss and risk.
Document risk assessments: Keep DSEAR assessments and maintenance records current.

Siting and installation basics (spacing, foundations and vehicle access)

Choose a location that meets HSE good practice for separation, safe access and impact protection. Install on a level, load‑rated concrete pad sized for the full tank mass and bund footprint. Keep clear of ignition sources and buried services, and guard where vehicles pass. Plan tanker access for turning, safe hose runs and hardstanding; ASTs typically need pump‑assisted drops, while USTs can accept gravity‑fed deliveries, which may lower delivery charges.

Separation and access: Maintain clearances and firefighting access in line with HSG176.
Impact protection: Fit bollards or crash barriers where vehicles operate.
Tanker logistics: Provide a marked standing area with lighting, security and clear signage.

Environmental protection and spill prevention

In bulk fuel storage, environmental protection starts with robust secondary containment and disciplined operations. Use bunded (double‑wall) tanks so any leak is captured by the outer wall, and monitor the interstitial space. Control deliveries to prevent overfills, secure fill points and hoses, and ensure you can respond quickly with the right equipment if something does go wrong.

Bunded design and monitoring: interstitial/leak checks recorded routinely.
Overfill control: high‑level alarm and automatic shut‑off tested.
Delivery discipline: supervised drops, drip trays, clean couplings.
Spill readiness: stocked kits, drain covers and trained responders.

Safety controls, hazardous areas and signage

Under DSEAR and HSE good practice (HSG176), bulk fuel storage must control ignition sources and manage vapours where dispensing or venting can occur. Classify and mark hazardous areas around tanks, fill points and dispensers, restrict access, and keep equipment in locked cabinets. Provide simple, robust controls that stop flow fast, warn early, and guide behaviour on site with clear signs and site rules that drivers, operators and contractors can follow at a glance.

Hazardous areas: Identify/mark zones and keep potential ignition sources and hot work out unless strictly controlled.
Emergency controls: Fit clearly labelled emergency stop, tested overfill/high‑level alarms, and isolate power when not in use.
Security and access: Use lockable cabinets and a fuel management system to authorise users and log issues.
Signage: Display flammable liquid warnings, no smoking/vaping, product identification, emergency contacts and site procedures.
Housekeeping: Keep fill points tidy, use drip trays, and remove residues to minimise vapour and slip/fire hazards.

Fuel quality, testing and routine maintenance

Keeping fuel clean and dry is what keeps engines, generators and dispensers reliable. In bulk fuel storage, neglecting quality leads to clogged filters, downtime and costly repairs; contaminated or “diesel bug”‑affected product is a known risk. Build a simple, routine programme that combines periodic testing, filtration and housekeeping with checks on the tank, gauges and interstitial monitoring so issues are caught long before they become incidents.

Sample and test fuel: Periodically check for water and visible contamination; act on any off‑spec findings.
Filter at dispense: Fit and maintain filtration to protect equipment; replace elements when performance drops.
Control water ingress: Keep lids/caps sealed and remove any water promptly to limit microbial growth.
Housekeeping: Keep fill points and cabinets clean; use drip trays and keep couplings tidy.
Inspect equipment: Check pumps, hoses, nozzles and seals for wear/leaks; repair or replace as needed.
Verify instrumentation: Cross‑check gauge readings, alarms and interstitial leak monitoring; record results.
Check containment: Inspect bunds/double walls for integrity and ensure vents/overfill devices operate correctly.

Deliveries, dispensing and inventory management

Effective bulk fuel storage hinges on well‑planned deliveries, controlled dispensing and tight inventory control. Schedule drops against forecast consumption and available ullage; ASTs typically need pump‑assisted offloads, while USTs can accept gravity feeds. Supervise every delivery and test overfill alarms. Dispense through metered equipment under a fuel management system (PIN/fob). Use cloud gauges/telemetry, set reorder levels, reconcile book vs gauge and investigate variances; retain delivery notes.

Tanker logistics: Safe standing, clear hose routes and supervised hook‑ups.
Authorised dispensing: Access control, transaction logs and meters you can trust.
Reconciliation: Use opening stock + deliveries – issues = closing stock; match to gauge, probe anomalies promptly.

Permits, planning and budgeting: what to expect

Expect an upfront compliance phase: DSEAR risk assessment, alignment with HSE HSG176, drawings/specs, and early conversations with planning authority, landlord and insurers. Plan design, civils/electrical works, delivery logistics and commissioning, and allow lead time for tank manufacture, transport and site access.

Bunded tank and dispensing equipment
Civils (pad, impact protection) and power
Installation, spill response, signage, routine inspections/testing

Training, competence and responsibilities

Under DSEAR and HSE guidance, anyone storing, delivering or dispensing fuel must be competent, trained and supervised. Nominate a responsible person to own the DSEAR assessment, daily checks, maintenance and control of contractors/deliveries. Provide induction and task‑specific training (dispensing, overfill/alarms, emergency stop, spill response), refresh routinely, and keep records. Supervise every drop, empower staff to stop unsafe work, and brief visitors on site rules.

How to size a tank and select a compliant supplier

Map realistic use and delivery lead times, pick a sensible days‑of‑cover, allow ullage, and consider peaks, growth and generator run‑time. Choose bunded (double‑wall) tanks for UK compliance, decide AST vs UST on space and access, and specify gauges, overfill alarms, filtration and a fuel management system.

Required capacity = (Average daily use × Days of cover) + Safety margin

Compliance: Bunded/double‑wall; HSG176 good practice and DSEAR support.
Protection: Interstitial leak monitoring and tested overfill alarms.
Turnkey: Design, civils, install, commissioning, maintenance and training.
Control: Secure dispensing, cloud gauges, reporting and reconciliation.

Key takeaways

The essentials are simple: size the tank to realistic demand, choose AST or UST for your site constraints, and use bunded, leak‑monitored designs. Build in overfill protection, secure dispensing, clear procedures and records, then maintain fuel quality and equipment.

Bunded/double‑wall tanks with interstitial monitoring.
AST vs UST: space, access, maintenance.
Control, test and reconcile routinely.

Need practical support or training? Speak to the dangerous goods specialists at Logicom Hub.