Innovative Engineering Gets Environment Agency Approval

The retro fitting of a unique liquid containment facility at an existing tank farm, has won HBPW plaudits from the Environment Agency.

Deoxygenated water – or liquid without oxygen – is lethal to fish stocks and wildlife if it leaks into the general water course.

Consequently, it has to be kept safely in a tank farm with provision to protect the public, and the environment, in the event of a catastrophic failure in one or more of the holding tanks.

Senior Partner, Paul Withers, said: “Tank farms can house any number of dangerous effluents, chemicals or flammable materials but, in this case, our client’s facility is used to contain deoxygenated water generated by the UK food industry.

“Despite the best planning in the world accidents still happen so it is in everyone’s interests to factor this in at the design stage.

“Ideally you would have a concrete slab beneath the containing tanks, with a retaining concrete bund wall of such height that it was capable of holding 110% of the volume of the biggest tank or 25% of the total volume of all tanks combined.

“But what do you do when an existing facility has grown organically over the years, has no containment around its perimeter and the concrete hardstandings, upon which the tanks sit, are full of cracks and other such vulnerabilities that might allow leakage of effluent? That’s where our client found themselves.”

Working with Bradford based sister company, HB Projects, Paul and the HBPW team turned to the drawing board and, by applying the specifications of CIRIA Report 736, which provides design recommendations for containment systems, they came up with an innovative solution.

“We engineered a ‘retro fit’ scheme to install low level perimeter concrete walls, with cantilevered baffle walls within the concrete bund, designed to deflect any catastrophic flows of water whilst also preventing the threat of fluid over-topping the perimeter dwarf concrete containment wall.

“As an adjunct to the concrete perimeter walls the team also constructed an innovative lagoon capable of accepting CIRIA specified liquid volumes, with ultimate sign off of our work by the Environment Agency.

“What we have done is both innovative and highly unusual,” added Paul, “but, as well as solving a problem, we like to think that our design has, once again, illustrated how HBPW promotes solutions that not only challenge the norm, but often produce innovative ‘firsts’ and this is a scheme that fits into that category.”

“On the one hand we have satisfied the Environment Agency’s basic requirement to properly consider containment of effluent, however, we have done so without slavishly following design recommendations. Innovative solutions requirement innovative thinking.”