Onshore oil and gas sector guidance

9. Storing and handling crude oil best available techniques (BAT)

BAT for the storage and handling of crude oil at onshore oil and gas sites.

9.1 Storing crude oil

The Environment Agency defines crude oil as any hydrocarbon extracted from a mineral well that is liquid at ambient temperature and pressure. This includes gas condensate.

You must store crude oil in a way that prevents it from polluting surface water, groundwater or land. You can find more information in:

9.2 Storage vessel design

The Environment Agency considers the following to be BAT. The storage vessel must be:

  • constructed from material that is impermeable to crude oil and water and resistant to corrosion
  • fitted with level detection and an overfill protection system
  • protected against over or under pressurisation
  • made with welded or flanged connections
  • fitted with a system that can detect water building up and can drain off water without a significant release of crude oil

The Engineering Equipment Users Association explains how you can design a storage vessel.

9.3 Containment system design

The Environment Agency considers the following to be BAT.

You must contain all storage vessels using a bund. The bund must:

  • have a capacity of either 110% of the largest vessel, or 25% of the total capacity of all the vessels it contains – whichever is greater
  • be able to withstand the hydrostatic head of liquid when full
  • be made of fire resistant material which is also impermeable to crude oil and water
  • be fitted with metal water stops to prevent leakage from any joints in the bund construction
  • have joint sealants that are resistant to crude oil and water and can maintain a seal during thermal expansion or contraction of the bund
  • have walls or floor that are not penetrated by pipework, cables and instruments
  • be fitted with a high-level alarm
  • be fitted with a sump to allow removal of accumulated liquid

Read Containment systems for the prevention of pollution (C736) to find out more about the design of containment systems.

9.4 Crude oil handling system design

The Environment Agency considers the following to be BAT. You must:

  • install ancillary equipment associated with the storage vessel, such as pumps, oil bath heaters and filters in the containment bund
  • protect ancillary equipment such as heat exchangers and filters against over pressurisation
  • locate crude oil pipework joints inside the containment bund, where possible
  • protect the ground beneath any crude oil pipework joints with an impermeable liner, if it is not protected by a bund
  • use an oil and water separation system that can handle oil-contaminated rain water extracted from the bund and accumulated water extracted from the oil storage vessel

9.5 Operating the crude oil handling and storage system

Your preventative maintenance programme must include maintenance of the crude oil storage and handling system and their associated containment. This maintenance programme must be part of your environmental management system.

You should:

  • routinely check and record the level in the crude oil storage vessels
  • regularly check the quantity of crude oil stored against the expected inventory - based on filling and export records
  • visually inspect the crude oil storage and handling system every day to identify any faults

9.6 Managing vent emissions from storing and handling crude oil

You should investigate all viable and appropriate options to use, or abate, gaseous emissions before you consider venting to the atmosphere. You must demonstrate to the Environment Agency that you have done this. If you conclude that venting is the only viable option, you should:

  • predict the quantity and nature of the emissions from your crude oil storage vessel vent - based on the expected composition of the crude oil and the predicted oil storage vessel feed rate
  • carry out sampling to verify the composition and the quantity of your emissions
  • carry out an odour impact assessment and produce an odour management plan if the crude oil you are storing or handling contains hydrogen sulphide
  • back vent road or rail tankers to the storage vessel during loading
  • describe any measures needed to reduce the concentration of hydrogen sulphide or other harmful substances emitted