Reading Station is powered by a fuel oil boiler system to heat the main station. Over a period of time they noticed that the fuel oil was lasting less time between refills. This happened to coincide with a period of harsh winters and the station staff initially thought that it was the weather that was consuming the fuel more rapidly as heating systems are operating at higher temperatures over longer periods.
The storage tanks area were inspected and it was found that the tanks had been leaking fuel probably over the last two to three years.
The Operations Team were asked to drill bore holes down to eight metres in line with Environment Agency recommendations and supply a method of removing subsurface oily waters from the local area to the tanks and proceed to filter it and remove the oils.
Supplying a pre-weir system to the site, that the bore holes were pumped into, and through prior to entering a filter container manufactured in-house. The filtration system included a delivery pump regulated to the set flows of the bore hole delivery. Once metering the system the water passed through a grease trap, down through a lamella plate pack with oils being diverted to an in built oil reception tank. The water then travelled through a 10 micron bag filter system and finally through an activated carbon filter. All clean waters were passed back to the surface drains and operations collected the oils once per month over four months before taking them for disposal off site.