Introduction
As you may be aware, the fifth edition of the ‘Design, Construction, Modification, Maintenance and Decommissioning of Filling Stations’, the Blue Book, was published late in 2024. As we have done previously, we have worked through the new edition and prepared this briefing note to highlight key changes from the fourth edition that we think may be relevant to those we work with. This briefing note is not a substitute for reference back to the Blue Book itself but is hopefully helpful as a primer. The changes discussed are not in any way a comprehensive list of changes.
The structure of the fifth edition is broadly the same as the fourth and appears to be less of a change than from the third to the fourth edition. The majority of changes are very minor, although some may have significant impacts on work on forecourts. The general focus of the changes is a continued emphasis on environmental protection and the inclusion of new fuels.
We have tackled the issues thematically below with references where appropriate. If you have any questions about how any of the changes affect your business, please feel free to contact us and discuss these. Contact us at info@cad-ltd.co.uk or by calling 01433 652220.
Electric Vehicle Charging
EV charging and its interaction with traditional fuels are now featured throughout the book.
A new section (2.2.3) has been added, which recommends not placing firefighting equipment near EV chargers due to the dangers of fighting EV fires. The arguments put forward for this are sensible, but questions about fighting EV fires more generally are still an open debate within the industry.
The placement of new EV chargers on a forecourt is now considered in several ways. Designers are asked to consider the movements of EVs and the interaction with other traffic in section 4.5.11. The risk of fuel or vapours travelling down a gradient and the need to intercept these with a drainage channel is considered in 3.3.1, with a useful illustrative diagram.
Although the guidance relating to the relationship between EVs and hazardous zones has not changed a helpful diagram has been included aiding understanding of this important restriction.
Section 9.5.11 requires that new EV charger installations should be notified to the local Fire and Rescue Service. This seems sensible, but we are not sure how it will work in practice, with there being no clear point of contact in most services to notify.
Fuel Infrastructure
Throughout the book, a requirement to protect fuel infrastructure from vehicle impact has been added. We welcome this requirement being made explicit, as we have noticed a lack of physical protection on some sites in recent years.
More details have been added regarding above-ground storage, which is becoming more common and driven by environmental concerns. Additional separation requirements for above-ground tanks greater than 45,000 Ltrs may now be required, with manufacturer advice needed based on testing. A separate section (5.4.2) covering above-ground pipework standards has now been included.
Consideration of secondary containment for suction lines is advocated where a risk assessment highlights an unusual risk.
Section 5.8.3.3 confirms that pipe fusion welding should be considered hot work. Generally, this means the work should be done only where a hot works permit has been issued.
More clarity has been provided on the normal operating limit of tanks, with reference to the Energy Institute publication ‘Guidance on design and operating limits for fuel storage tanks at retail filling stations’. Operators may be interested to know that the recommended working capacity of Tankscan vary between 90% for tanks below 10,000ltrs and 97% for tanks above 30,000ltrs.
The guidance on the construction of tank chambers has changed, with a greater emphasis on the chambers being watertight. Section 5.2.3 makes clear that brick and concrete chambers are no longer acceptable. While this will not affect new sites, it may affect sites where repumping or tanklining is being undertaken.
Environmental Protection Measures
Chapter 6, covering leak prevention, containment and detection has been restructured, but the same overall method for assessing a site and the general requirements have not changed significantly. Descriptions of wet stock monitoring systems and leak detection types are now clearer and easier to understand, which is a welcome improvement.
Class III leak detection is now mandated for all tank chambers (Section 5.2.3.2 and table 7). We recommend the use of discriminatingsensors in chambers for a quick and safe determination of whether the chamber is allowing water to enter or if there is a fuel leak. Site staff must be trained to interpret any alarms triggered by these sensors and know the dangers associated with tank chamber entry. There is a risk that well-meaning but untrained staff try to enter a chamber to resolve an alarm and come to harm as a result.
Table 8 now acknowledges that class I detection systems can be set up to shut down submersible pumps on pressure systems automatically.
Drainage
The drainage section of the book remains similar to the fourth edition but has some important additions and clarifications. It is now clearer than ever that the dispensing area and tanker standing area should be draining to a foul sewer if one is available. The guidance is also clear that a jet wash cannot be installed without a foul connection or a sealed tank from which the effluent is disposed via a tanker. Designers are now also required to consider the drainage condition downstream of the site, and the section on spill isolation (8.4.6) has been expanded.
EVs and Ad-blue (DEF) areas now receive additional attention. Significantly, it is expected these should be drained as distinct areas. Section 4.6 required the water runoff from firefighting activities to be considered with reference to contaminates such as Perfluoro octane sulfonate (PFOS). We see this as sensible but understand the frustration of operators who are considering such matter, when they see large numbers of EV chargers being installed in car park parks under permitted development rights with no such consideration.
Below is our version of the revised diagram for a typical drainage schematic.
A separate diagram is now provided for areas where no foul sewer is available, which includes reference to other (additional) on-site treatment before discharge. Our experience is that regulators are becoming increasingly stringent when considering such schemes, with features like rain gardens or swales becoming the norm in this type of circumstance.
Section 3.3.7 now requires consideration be given to supporting to interceptor vent. We regard this as an important addition. During site surveys of older sites, we often struggle to find interceptor vents, with improvised constructions from drainpipes often having fallen over or been damaged and never replaced in the past.
Ad-blue (Diesel Exhaust Fluid)
Numerous additional references to Ad-blue are throughout the book, reflecting the growth of this market (e.g., 4.5.3, 8.9, and an expanded chapter 11). Chapters 8 and 11 now clearly recommend that Ad-blue be stored and dispensed away from hydrocarbon fuels and drainage not directed through the forecourt interceptor.
The book highlights that DSEAR has been covering Ad-bluesince 2015 as a substance corrosive to metals, and so a DSEAR risk assessment is required for any Ad-blue installation or storage. We suspect that many operators and even some DSEAR assessors, who work more commonly with hydrocarbons, are unaware of this requirement. As a consequence of the DSEAR classification, stringent maintenance and testing requirements are laid out.
The handling recommendations are more detailed, and staff training on Ad-blue is mandated. A specialist spill kit for Ad-blue is also needed—not the same as a hydrocarbon spill kit.
The enhanced chapter 11 includes additional environmental protection considerations related to Ad-blue, including a requirement for below-ground pipework to be double-skinned and have leak detection. Where Ad-blue is sold in containers, the book says provision for the return of used containers should be made.
Recommendations for the shelf life of Ad-blue are included based on temperature. These are borne out by our experience, with some operators having experienced issues with crystallisation of Ad-blue. We suggest stock levels of Ad-blue are carefully considered against throughput to avoid this.
Overall, the trend is to require a more careful approach to Ad-blue than is currently prevalent, with a strong push towards Ad-blue being in a separate area with dedicated facilities. Retailers may want to evaluate their current procedures for Ad-blue and factor in the requirements when considering if they can responsibly introduce Ad-blue dispensing on a site.
New Fuels
References to new, or alternative fuels, are peppered throughout the revised book, and include hydrotreated vegetable oil, additional information on various other biofuels and blends, hydrogen and a rewritten Autogas (LPG) chapter. Section 2.7 provides a helpful high-level guide on the issues to consider when new fuels are introduced in a petrol station environment.
General Design and Practice Items
There are a few general items that have been added or amended throughout the book that we will discuss here. Overall these might be considered ‘tidying’ up and reflections of best practice and we believe most responsible operators will not be significantly affected by these changes, although they are still noteworthy.
A section on the confined space regulations has been added(2.6.2.4), which regard as an important addition, as a number of very serious incidents have occurred where workers have asphyxiated in tanks or tank chambers. We would urge anyone commissioning work on tank chambers to ensure their contractors are prepared for this potential hazard.
Section 4.4.2 requires staff to have visibility of dispensers from the counter area of shops. A raised floor behind the counter is now suggested, although we have observed a general trend away from this solution. Building Control Bodies are often challenging this practice on accessibility grounds, particularly when other methods, such as CCTV are available and often more effective.
Section 4.11.1 now requires height warning signs on canopies and clear entrance and exit signage. A tannoy system is now explicitly required in section 7.6.6 for attended self-service sites. This has long been an implied requirement, but we believe this is the first time this has been a stated requirement.
A new emphasis at the start of the chapter on electrical installations on the guidance being for skilled persons has been added. We welcome this, but feel it is a missed opportunity to clearly outline electricians working on the forecourt should have suitable CompEx certifications or be working under the supervision of someone with these certificates.
Maintenance and Decommissioning
Chapter 12 covers the decommissioning of tanks or sites as a whole. Sections 12.1.2-4, which outline both the relevant legislation and the information an operator needs to provide to the Petroleum Enforcement Officer when decommissioning a tank, are helpful additions to the text. We hope they will be helpful to both operators and Petroleum Officers, who, historically, have not always been consistent in their requests between authorities.
Table 16 has been added and provides a helpful reference on methods suitable for temporary and permanent decommissioning. Notably, foamed concrete is no longer permitted as a method of decommissioning following an incident in 2009. Additional details on foam filling techniques are included.
The language concerning the need to remove tanks with class II monitoring has been strengthened. Section 12.2.2.14 says such tanks ‘should always be removed’ as glycol is a contaminant, so they cannot be made safe in situ. It is also not permitted to leave any tanks under structures.
Significantly, for operators of older sites with multi-compartment tanks, section 12.14 makes it clear that if a compartment fails and cannot be repaired, the whole vessel should be taken out of use. This has serious implications for some operators with older sites. In a similar vein, section 5.2.1 requires that when the external skin of a double-skin tank has failed, the tank is removed.
12.15 makes it clear that operators are responsible for making tanks safe when leaving a site to be redeveloped. We agree with the principle but suspect there will be occasions where a business fails where this does not occur.
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