We recently visited a site where a bulk installation of LPG tanks had been installed; these were used to routinely refill HGV fuel tanks. The installation had been installed by a well-known compressed gas provider and, to the knowledge of the business, was designed to comply with the requirements of DSEAR.
However the businesses insurers had requested that an independent DSEAR assessment was completed and they approached us to undertake this on their behalf. We visited site and looked in detail at the installation and at first glance all suitable controls appeared to be in place.
On closer inspection it was noted that the earth straps did not connect to a suitable earth rod; they relied upon the tank frames being bolted to the concrete base as the means to earth these. Given the tanks held in excess of 20,000 litres we suggested this was not a suitable means and it would be difficult to prove an effective route to earth.
It is potentially possible that in certain conditions when the ground is dry and free from moisture that instead of providing a source to earth that the lines could become positively charged. Not a good scenario, given the highly flammable nature of the tank contents.
If your controls include earth bonding we suggest that you routinely have them checked to confirm on-going integrity.
