Preparing for all eventualities
Some armchair experts claim that accidents never happen. If every piece of equipment is properly designed and used correctly, if every worker is properly trained and never takes a short cut, and if every process carried out on site is conducted as it should be and monitored rigorously, then nothing will go wrong. But in the real world accidents do happen.
The inevitability of spills is an important factor in the design and construction of tank storage facilities. Tanks are surrounded by bunded areas to catch spills and fitted with warning devices to detect leaks and overflows before they become serious. But bunds can leak (or be overtopped) and any warning device can fail. If they do fail a second level of spill control to limit the spill and a clean-up regime is required to minimise environmental damage and make sure the site is safe to resume operations as quickly as possible.
In the wake of the Buncefield fire in the UK during December 2005 tank storage operators everywhere are looking extra carefully at the safety of their systems. Whilst overflows and leaks of less volatile materials are unlikely to lead to such a catastrophe, they are nevertheless expensive to deal with. Several less dramatic cases that occurred this year show that there are still lessons to be learnt. On 2 July a light sheen of oil was noticed drifting in the Firth of Forth (estuary of the river Forth) in Scotland. The Scottish Environmental Protection Agency (SEPA) traced the source of the slick to the Grangemouth refinery operated by Ineos. The nature and volume of oil released has not been disclosed, nor have the mechanics of how it happened been revealed. Ineos' press officer Kath Wilson would only say that they were unable to go into detail while the matter is under investigation. SEPA demanded work be done immediately to prevent a recurrence and went as far as to station a boat in the estuary to monitor the work on site.
In this instance the spill was small and no clean up work was required in the estuary. According to SEPA's Lin Bunten nature is the best possible form of clean-up in this case, as no significant accumulations of oil have gathered on shore and no dead birds or fish have been identified as a result of this incident.
Not all spills are so benign.
A more serious incident
occurred on the same day
4000 miles away in
Coffeyville, Kansas, US, when
the Verdigris river over
topped its levee by four feet
and inundated a refinery.
Some 71,400 gallons of crude
oil mixed with the flood water
and caused widespread
damage. And when a four
million gallon tank of diesel
owned by Ashland Oil in
Pennsylvania split apart in
1988 it polluted the drinking
water supply used by more
than a million people.
