COMAH Bund Services
CIRIA 736 encourages COMAH sites to ensure the competency of the design and build contractor for their secondary containment. GPT have a proven track record for carrying out all aspects of bund work for both upper and lower tier COMAH sites.
The Buncefield incident in 2005 demonstrated the worst case scenario of having improper bunding, the incident was exacerbated by the failings in the sites bunding allowing flammable liquids to spread and pollutants to enter the environment. CIRIA 736 - Containment systems for the prevention of pollution lays out specialist requirements for bunding on COMAH sites. We offer a comprehensive range of services covering all aspects of bund works on COMAH sites.
Our COMAH bund services include:
- COMAH bund design
- COMAH bund construction
- COMAH bund surveys
- COMAH bund repair
- COMAH bund lining
- COMAH bund maintenance
CIRIA 736 covers maintenance, extension and modification of an existing bund as well as the construction of a new containment facility, and states: “In summary, bunds should be designed and constructed to comply with a number of performance criteria that should take into account all credible:
- modes of escape of pollutant from the primary storage vessel
- modes of failure of the bund
- incident scenarios
- loadings
- chemical and physical exposure (particularly fire).”
Due to the high health and safety and environmental risks posed by the liquids stored on COMAH sites the specification for bunding often goes beyond the requirements of broader legislation on secondary containment. Aspects in which CIRIA 736 is stricter include:
- Recommendations on minimum and maximum wall height.
- Specialist linings/coatings
- Construction Material
- Proximity of tanks to bund walls
- Ability to cope with hydrodynamic and hydrostatic pressure
- Bund wall penetrations
Fuel and firefighting liquids flowed off site (Buncefield)
Loss of sealant between penetrating pipe and bund wall (Buncefield)
COMAH Bund Case Studies
Extracts from legislation and guidance
“The Buncefield incident in December 2005 highlighted many shortcomings with the design and construction of the secondary containment facilities at the site that failed leading to a MATTE (Major Accident to the Environment). The subsequent HSE (2011) report contained a number of recommendations for the design and construction of secondary and tertiary containment.”
Containment systems for the prevention of pollution (C736)
“The quality of design and construction is fundamental to the integrity of the containment system. It is therefore imperative that any designer, contractor or maintenance works operative engaged to construct, extend or modify a containment system is experienced in designing and constructing to the relevant class of containment. As a minimum, the parties should have a proven history of carrying out the relevant type of work.
All works need to be properly designed, whether it is the construction of a new or replacement bund, the extension or modification of an existing bund, or repair and maintenance work as set out in current standards.”