Microbac has successful undertaken the clean up of a diesel spill at a site in Cumbria, UK. The oil escaped from a large storage tank, located at the top of an incline after a problem occurred with closure of the valve. The position of the spill resulted in oil running down the incline and into the site drainage system.
In response to the client's request, Microbac installed a biological treatment system designed to collect, circulate and treat the oily run-off with biological cultures specially selected for their ability to degrade hydrocarbon based oils.
The treatment system utilised the natural incline of the site to collect and contain the run off wastes from the treatment area to prevent further contamination of the drainage system. A network of spray heads connected by plastic pipework was positioned over the spill area. A Bioreactor was used to grow up oil degrading biological cultures, under optimum conditions, which were then distributed via the spray network, over the contaminated soil. Oily leachate from the soil was collected in plastic lined trenches at the bottom of the site and pumped back to the top of the site and through a balance tank and into the Bioreactor where further degradation of the oil occurred. Here, the Bioreactor served a dual purpose - initially, to provide a source of viable bacteria to disperse into the soil to initiate degradation of the oil and, secondly, as an efficiently treatment system for re-circulated oil. As the oily waters were re-circulated through the unit and the contaminated ground, the bacteria in the whole system began to degrade efficiently the diesel oil.
After a period of four weeks, analysis of samples from the soil and the water in the collection trenches showed that levels of diesel oil had fallen below the 5 mg/l pre-determined by the Environmental Agency for a successful clean-up operation and the work was completed to the client's satisfaction with minimal site disturbance.