3250 A comparison of risks related to the storage of hydrocarbons in above-ground and underground tanks at petrol filling stations

Overview:

In 2012 the Environment Agency and the Energy Institute commissioned a project to compare the risks associated with different tank storage and dispensing options at retail petrol filling stations (PFS)s.

This was done to progress practical protective solutions to industry’s ongoing challenges arising from the position statements set out in Groundwater Protection: Principles and Practice (GP3) (Environment Agency, 2012) particularly arising from the Environment Agency’s approach for above-ground storage in the most sensitive locations.

The project compared the qualitative spill and other risks of contamination to groundwater resources and the relative risks to human safety from above-ground and underground storage solutions. The report used a relative risk assessment methodology to compare the environmental and safety risks from four generic types of underground storage tanks (UST)s and above-ground storage tanks (AST)s:

• Single skin USTs
• Lined single skin USTs
• Modern double skin USTs with automatic leak detection applied between the double skins.
• ASTs with double skin filled with porous concrete and leak detection applied, plus a bund below and around the tank.

The main project objective was to provide support to planning submissions that takes account of all relevant environmental and safety risks by developing a means to assist the Environment Agency, operators of PFSs and other interested parties.