The document discusses bund linings for creating effective secondary containment. It provides information on bund design requirements according to UK regulations, including that bunds should be able to contain at least 110% of the volume of stored liquids. It also discusses bund lining types, factors to consider for bund replacement versus relining, and regulations and guidance documents pertaining to bund construction and oil storage.

1. BUND LININGS
Creating Effective Secondary Containment
Requirements, Recommendations and Best Practices
Stephen Bowen, Managing Director, Strandek GRP Systems
WWW.STRANDEK.CO.UK

2. WWW.STRANDEK.CO.UK
Contents
ØUnderstanding Bunds
ØBasic Bund Design
Considerations
ØWhere Are Bunds Used?
ØBund Failure: Causes &
Examples
ØTypes of Bund Linings
ØBund Design
ØBund Replacement vs. Relining
ØTypes of Bund Linings
ØBund Lining
ØDesigning an Effective Bund
ØBund Replacement vs. Relining
ØDisadvantages of Relining a
Bund
ØChoosing a Bund Lining
Specialist
ØRegulations &
Recommendations
ØAbout Strandek®
ØContact Us

3. Bunds are structures typically built around
tanks and vessels that hold large amounts
of potentially hazardous chemical liquids.
Built from concrete and mortar, their walls
are typically several inches thick and they
should be able to contain an excess of the
total volume of all liquid within their
perimeter, should it leak.
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Understanding Bunds
What is a bund?
High level
detector
Pipework
over wall
Blind collection sump
Drains to
sewer or
stop tank
Collection sump
Truck loading and
unloading area
undercover
Bund big enough to contain >110% of the volume of the target tank
Spills from hose
couplings within
bund area
Pump
Truck
unloading
area
Outer bund wall (brick)
Bund wall inner lining
Steel tank wall
Schematic of a standard bund surrounding a storage tank with associated equipment and features
Bunds are a second line of defense against
catastrophic leaks from primary containment
vessels like storage tanks and reactors. Their
purpose is to “defence for preventing,
controlling or mitigating major hazards
events” according to the UK’s HSE advice on
bunding.
Why are bunds needed?

4. WWW.STRANDEK.CO.UK
Basic Bund Design Considerations
Secondary containment refers to a containment structure or bund wall around equipment or tanks holding large volumes of
liquid. If the equipment leaks or the tank is overfilled, the liquid is contained and thus prevented from flowing into other parts of
the facility, where it could create a safety and environmental problem. As such, careful design of the bunded area and
surrounding equipment needs to be undertaken
Bund walls are typically made from earth or concrete. If a storage tank fails, a bund would
contain any leaked liquid, particularly at higher elevation. They prevent leaked liquids from
flowing directly into adjacent process areas.
Bund wall should be impervious to tank liquids and the bunded area should have an impervious
floor. Walls can be made impervious via protective bund linings like fibreglass (GRP), epoxy,
polyurethane, etc. These resins are chemically inert, durable and non-porous unlike concrete.
Spacing in/around the bund area should permit emergency equipment access; overhead piping
from other systems, pumps, filters, manifolds, and heat exchangers should all avoid the bunded
area.
Bunds: a form of secondary containment
Bund Walls
Concrete bund wall
Bund wall internal lining

5. Where Are Bunds Used?
Bunds installed at industrial production and
processing facilities are designed to contain:
Fuels and oils: petrol, diesel, motor oil
Food processing: vegetable oils, dairy, soft drinks
Acids: sulphuric acid, hydrochloric acid,
lactic acid
Alkalis: sodium hydroxide, sodium carbonate, potassium
hydroxide, potassium carbonate.
Water: wastewater, treated water, sewage
Breweries/distilleries: beer, whiskey
Solvents: ethanol, acetone, methanol
Agriculture: fertilizer, diesel, water
Industries and Sectors Requiring Bunds
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Information on fuel & oil bunds is a significant to comply with UK
HSE regulations on oil storage

6. Bund Failure: Causes & Examples
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CASE STUDIES
Floreffe, Ashland Oil (1988): 4 million gallon tank of fuel oil released a
surge wave that swamped the bunded area. This lead to the damage of
another tank and a $4.6 million fine.
Iowa (1997): 1 million gallon tank of ammonium phosphate failed
Michigan (1999): the rupture of a 1 million gallon tank of ammonium
polyphosphate. Lead to damage of an additional 3 tanks.
Ohio (2000): 1 million gallon liquid fertilizer tank ruptured, damaging
nearby tanks. This caused a wave that penetrated the concrete bund,
forcing 5 rigs into the nearby river.
Ohio (2000): tank containing 1.5 million gallons of ammonium phosphate
ruptured. Caused three other tanks to leak, overflowing the bund leading
to the contamination of 450,000 gallons water that would have been
sent for drinking water.
Breakdown, & damage: signs of bund failure
Physical
• Impact (forklift trucks, falling objects, age-related wear)
• UV breakdown of the outer lining leading to substrate
exposure
Chemical
• Incompatible, ineffective liners or no liner, leading to
chemical attack and ingress into the bund wall
• Exposure of underlying layers that lack chemical resistance via
UV breakdown, physical wear
Biological
• The presence of microbials like fungus and vegetation could
indicate a failure of the bund lining, making it susceptible to
leaks

7. Bund design requires careful consideration of layout and materials. Its structural
characteristics are important to withstand impact and high liquid volumes and
its ability to effectively contain those liquids via an inert, unreactive and
impervious lining or coating.
For secondary containment bunds of either variety you must make sure:
• the bund is impermeable to oil and water - oil and water cannot pass
through
• Bunds constructed from masonry and concrete are likely to need a rendering
or coating on the internal surfaces of the base and walls to make them
impermeable.
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“Bund design according to the UK Government for pollution control and secondary containment should be
designed to adequately accommodate stored substances based on their size and construction.”
Bund Design
Guidance & Recommendations

8. Bund Design
Bund design according to the UK Government for pollution
control and secondary containment should be designed to
adequately accommodate stored substances based on their size
and construction. Moreover:
• The total volume of the number of storage tanks in a single
bund should not exceed 60,000 m3
• Incompatible chemicals that are hazardous when in contact
should have separate bunds
• Accumulated rainwater is removed regularly
• Storage tanks have individual bunds
BUND CAPACITY
• at least 110% of the capacity of storage
containers over 205 litres capacity to
accommodate foaming and surges
• at least 25% of the capacity of storage
containers up to 205 litres capacity
BUND LOCATION
• 10 meters from watercourses, open
drains, gullies, unsurfaced areas or
porous surfaces
• 50 meters from wells, springs or
boreholes
Bund replacement versus refurbishment
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9. Types of Bund Linings
A range of different resins-based lining systems are ideal for bunds
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EPOXY
• Good mechanical strength
• Can be combined with aggregate
• Low flexibility – suitable for
demanding environments
• Chemically resistant to a wide
range of substances
• Fully impervious, highly durable
POLYURETHANE
• Excellent flexibility – up to 400%
elongation capacities
• Seamless and versatile
• Chemically resistant to a wide
range of substances
• Marginally more expensive than
epoxy
FIBREGLASS (GRP)
• Composite system made from
glass fibre mat and polyester resin
• High strength-to-weight ratio
• Low cost vs. other systems
• Chemically resistant & impervious
to a range of liquids
• Good elongation & flexibility
POLYUREA
• Spray-on system
• Requires expensive equipment
• Versatile and easily applied
• Requires adequate surface
preparation and application
• Chemically resistant & impervious
to a range of liquids

10. Bund Linings
Consideration should also be given to bund wall height:
• Low bund walls: (height: 1 - 1.5 m) aid emergency worker
access, but risk chemical contamination if a pressurised
vessel leak occurs higher up or if a sudden release of high
volume liquid occurs and causes an overflow.
• High bund walls: account for the possibility of the tank or
vessel floating and tipping in the event of a large volume
liquid leak.
More detail on bund design, capacities, shapes and structural considerations is available from the NBS's guidelines for bund construction.
Bund replacement versus refurbishment
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11. WWW.STRANDEK.CO.UK
A lining is a form of surface coating that protects the
inside of a vessel or structure, rather than the outside.
In the context of bund walls and floors, its purpose is to
contain any liquid that could be released from the
primary vessel to protect the bund structure, which is
typically concrete or mortar.
Bund linings are typically thin layers of resin-based
substrates commonly combined with other materials like
aggregates or glass/textiles for added performance.
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What is a Bund Lining?
Designing an Effective Bund

12. “Bund wall and floor construction and penetration
joints should be leak-tight.
Surfaces should be free from any cracks,
discontinuities and joint failures that may allow
relatively unhindered liquid trans-boundary migration.
As a priority, existing bunds should be checked and any
damage or disrepair, which may render the structure
less than leak-tight, should be remedied.”
See more via Safety and environmental standards for fuel storage sites (Part 42: page 16).
Seamless and leak-proof surfaces
Bund Replacement vs. Re-lining
Concrete splitting Blistering, loss of lining
Joint failure Chemical / biological staining
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13. Bund replacement versus refurbishment
To get a balanced assessment when comparing the benefits of re-lining a bund versus a full
replacement, several considerations need to be taken into place.
To repair or refurbish a bund, the primary focus is on surface preparation to render the existing
bund amenable to coating, concrete repair and the application of a lining.
An effective solution, replacement is
expensive, time consuming and generates
a higher carbon footprint since far more
concrete is used.
To repair or refurbish a bund, the primary
focus is on surface preparation to render the
existing bund amenable to coating, concrete
repair and the application of a lining.
Option 1: Construct a new bund Option 2: Re-lining a bund
Bund Replacement vs. Re-lining
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14. Cost
• On average the cost of a bund replacement could be 30% of
the cost of a new bund.
• This equates to £2,400 to re-line the bund versus £7,600 to
replace it.
• These figures are estimates; every bund replacement and
relining project are likely to differ, but this calculation does
demonstrate potential cost savings for the customer.
• The major cost contributor to the bund replacement is
associated with the underlying bund substrate itself.
Bund Replacement vs. Re-lining
How much does it cost to re-line a bund vs. a full replacement?
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Full
replacement
Re-lining
£7,600
£2,400
£-
£1,000
£2,000
£3,000
£4,000
£5,000
£6,000
£7,000
£8,000
COST(£)
Re-lining a bund is
30% cheaper than a
replacement
Replacement factors
• Removal of existing bund
• Bund construction
• Surface preparation
Re-lining factors
• Repair of bund
• Surface preparation
Replacement factors
• Materials
• Workmanship
• Bund lining
Re-lining factors
• Bund lining
• Workmanship
Full
replacement
Re-lining

15. Downtime
From an operational perspective, the downtime to repair or
refurbish an existing bund, is a major consideration if the primary
containment vessel cannot be used for storage during that period.
This means that for every 1 day spent re-lining and refurbishing
an existing bund, around 2.6 days will be spent installing a bund
replacement.
This is likely to change in a real-world setting with different
considerations like additional manpower and modular systems,
but it does highlight that relining can be as low as 40 % of a full
replacement.
Bund construction time can vary; some systems are modular in
certain situations and can result in greater cost savings for bund
re-linings.
Bund Replacement vs. Re-lining
What is the downtime for re-lining compared to replacement?
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6.5 HOURS
2.5 HOURS
0
1
2
3
4
5
6
7
TIME(HOURS)
Full
replacement
Re-lining
Re-lining a bund is
2-3 times faster
than a replacement

16. Disadvantages of a Re-lining a Bund
When not to re-line an existing bund…
There are several reasons not to reline a bund. These centre on instances where:
• Catastrophic failure of the existing bund, calling for a redesign or rebuild
• Severe damage to the existing bund via impact, rendering it beyond repair
• Indication of damage or chemical contamination in the core structure of the bund
• Bund design is deemed in breach of current regulations or is deemed unsafe based on a
safety review
• A change in the volume or type of material housed in the primary storage tank/vessel has
occurred
In these instances, the existing bund should be modified to ensure that it is compliant with
existing regulations on secondary containment.
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17. Choosing a bund lining specialist
A range of systems exist, from epoxies to urethanes and fibreglass GRP.
When selecting a bund lining system or coating, customers should focus on:
• Chemical compatibility with primary containment liquids
• System robustness and durability
• Expected & proven lifetimes
• Skill of applicator
• Accreditations: CHAS, Construction Line, etc.
• Experience in prescribed application
• Case studies: proven performance
• Good links to top tier manufacturers with ISO 9001 & 14001
certifications
• Extent of repairs and possible redesign requirements
Guidance on Choosing a Bund Lining Specialist
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18. Control of Major Accident Hazards
Regulations (COMAH)
Secondary containment
https://www.hse.gov.uk/comah/sragtech/techmeascontain.htm
Secondary and Tertiary Containment of Bulk Hazardous
Liquids at COMAH Establishments
https://www.hse.gov.uk/comah/guidance/bulk-hazardous-
liquids.pdf
Safety and environmental standards for fuel storage sites
(Part 42: page 16),
http://www.hse.gov.uk/comah/buncefield/bstgfinalreport.pdf
Legislation and guidance:
The Control of Pollution (Oil Storage) (England) Regulations 2001
• http://www.legislation.gov.uk/uksi/2001/2954/regulation/3/made
• http://www.legislation.gov.uk/uksi/2001/2954/regulation/4/made
Above ground oil storage (including petrol, diesel, mineral oil,
heating oil or vegetable oil)
https://www.gov.uk/oil-storage-regulations-and-safety
Regulations & Recommendations
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19. UK Environmental Agencies
www.environment-agency.gov.uk
Scottish Environment Protection Agency
www.sepa.org
www.defra.gov.uk
Welsh Environmental Protection Agency
www.naturalresources.wales
Bund Design Codes & Standards
CIRIA163 - Guidance note for the Control of Pollution (Oil Storage) (England)
Regulations 2001
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment
_data/file/69255/pb5765-oil-storage-011101.pdf
BS8007:1987 - https://shop.bsigroup.com/ProductDetail?pid=000000000000172967
BS EN 1992-3:2006 - Eurocode 2. Design of concrete structures. Liquid retaining and
containing structures
https://shop.bsigroup.com/ProductDetail/?pid=000000000030047506
Construction of bunds for oil storage tanks (R163D)
https://www.ciria.org/ItemDetail?iProductCode=R163D&Category=DOWNLOAD&Websit
eKey=3f18c87a-d62b-4eca-8ef4-9b09309c1c91
Oil storage regulations for businesses
https://www.gov.uk/guidance/storing-oil-at-a-home-or-business#secondary-containment
Regulations & Recommendations
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20. History
• Founded in 1976
• Specialists in cold-applied, resin-based linings and coatings, from fibreglass (GRP) to epoxy and polyurethane
Responsibility
• A strong health, safety & environmental policy
• Trained, certified and dedicated applicators
Service & Performance
• Experts in a range of resin-based composites, from fibreglass to polyurethanes and epoxies.
• Close working relationship with leading manufacturers
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About Strandek®
Experts in surface waterproofing and chemical protection

21. Contact Us
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Steve Bowen
Managing Director & Founder
Phone: 01633 250652
Email: steve.bowen@strandek.co.uk
Paul Chapman
Senior Manager
Phone: 02920 900011
Email: paul.chapman@strandek.co.uk
Main Address
Strandek GRP Systems
Croes-Carn-Einon, Newport
South Wales, NP10 8RR
www.strandek.co.uk
Company number: 01448607
Jan Pitt
Finance & Administration
Phone: 01633 250652
Email: admin@strandek.co.uk