Guidance

Refineries and fuel: examples for your adapting to climate change risk assessment

Updated 17 May 2023

Applies to England

Possible impacts and mitigation measures to consider when preparing your climate change risk assessment.

Summer daily maximum temperature

This may be around 7°C higher compared to average summer temperatures now, with the potential to reach extreme temperatures as high as over 40°C with increasing frequency based on today’s values.

Impact 1

Increased potential for non-methane volatile organic compound (NMVOC) emissions from storage tanks with atmospheric vents, with associated odour impacts.

The mitigation for this could be:

• consider implementation of vent control or vent treatment measures
• keep existing zoning distances around key plant under regular review
• regularly review the cooling capacity to ensure it is sufficient to operate the plant safely especially if dry cooling is used and consider what would the consequential effect be of volatile organic compound (VOC) carry over due to poor cooling on process operations

Impact 2

There would be a greater likelihood of activation of pressure relief systems on sealed storage systems leading to increased routine flaring.

The mitigation for this could be to consider installing insulation or cooling on tanks storing:

• volatile liquids
• liquefied gases under pressure

Impact 3

There could be an increased risk of fire on adjacent facilities, woodland and common ground, which could spread to the refinery or impede local fire and rescue services (FRS) from accessing site.

The mitigation for this could be to identify boundary locations that present a fire risk. For land owned by the refinery operator, maintain good housekeeping, such as:

• removing rubbish and vegetation that could ignite
• clearing a firebreak track next to the boundary fence

Impact 4

There could be a risk of wildfires affecting power supply to key areas of plant.

The mitigation for this could be, for land owned by a third party, to engage with neighbours and electrical supply companies to help manage fire risks.

Impact 5

Increased energy and water consumption due to added load on cooling systems.

The mitigation for this could be to review the capability and design of cooling systems to see if efficiency improvements can offset the added demand.

Impact 6

Risk of overloading vacuum systems.

The mitigation for this could be to review the design of vacuum systems to ensure they can cope with a larger ambient temperature range.

Impact 7

Increased potential for odour generation from effluent treatment systems, including storage tanks and lagoons.

The mitigation for this could be to:

• monitor and maintain effluent plant performance to maintain oxygen levels, as required
• review the plant design to minimise potential for fugitive odours, including containment and abatement systems

Winter daily maximum temperature

This could be 4°C more than the current average with the potential for more extreme temperatures, both warmer and colder than present.

Impact 1

In extreme cold weather, the risk of:

• failure of trace heating systems
• freezing of cooling water, resulting in blockages – particularly on long pipelines and storage in exposed areas

This could also lead to process failures and flaring events.

The mitigation for this could be to regularly inspect and maintain insulation, particularly on pipework and equipment in exposed areas of the site.

Impact 2

Increased risk of water pipework ruptures, affecting:

• boiler condensate
• process water
• cooling water
• effluent systems

This in turn may lead to process interruption and flaring.

The mitigation for this could be:

• considering added insulation on pipework containing water
• reviewing operating procedures to make sure pipework is not left full of static water when not in use
• identifying any potential dead-legs where static water may be held up

Impact 3

Failure of pH control due to caustic systems solidifying (for example, effluent treatment)

The mitigation for this could be to review capability of caustic systems to remain liquid at anticipated colder temperatures.

Impact 4

Extremes of hot and cold temperatures are likely to affect the performance of biological treatment facilities and may kill the biological organisms.

The mitigation for this could be to develop contingency plans for failure of biological treatment facilities.

Impact 5

Viscous materials such as crude oil, crude distillation unit (CDU) and vacuum distillation unit (VDU) residues become immobile in cold weather causing process interruptions and damage to pumping equipment.

The mitigation for this could include:

• regularly inspect and maintain insulation and trace heating, particularly on pipework and equipment in exposed areas of the site
• ensure equipment is drained when not in use

Impact 6

Frozen on-site roadways may restrict access for staff and emergency vehicles.

The mitigation for this could include:

• regularly inspect and maintain roadways during winter and remove any standing water
• ensure grit is available to treat road surfaces

Impact 7

Damage to site infrastructure from snow-loading over extended periods.

The mitigation for this could be to review the design of structures to withstand increased loading.

Daily extreme rainfall

Daily rainfall intensity could increase by up to 20% on today’s values.

Impact 1

Flooding could lead to:

• power failure
• process disruption
• infrastructure damage
• restrictions on site access for staff and emergency services

The mitigation for this would be to prepare a flood plan with reference to the guidance Preparing for flooding: A guide for sites regulated under EPR and COMAH.

Impact 2

Bunds and tertiary containment fill up with rainwater, reducing the capacity for containing a spillage of a hazardous material.

The mitigation for this could be to:

• provide level detection and alarms for bunds and tertiary containment
• implement a frequent visual inspection regime during periods of high rainfall
• maintain good housekeeping standards to make sure the ground and other surfaces do not contaminate floodwater

Impact 3

Roof drains on floating roof tanks could become overwhelmed.

The mitigation for this could be to regularly review of tank roof drainage capacity to reduce risk of overflow in extreme rainfall events coupled with good housekeeping to maintain installed capacity.

Impact 4

Potential for contaminated floodwater or surface water run-off from the site, causing pollution.

The mitigation for this could be to:

• segregate storm water from effluent drains where practical
• provide suitable balancing capacity

Impact 5

Effluent treatment facilities overwhelmed with storm water, leading to direct discharge of untreated effluent to controlled water.

The mitigation for this could be to:

• identify structures and roofs that might be vulnerable to damage from snow-loading
• put in place measures to clear snow

Impact 6

Heavy precipitation falling as snow in winter could result in damage to equipment and collapse of old fragile roofs. Access around the site may also be hampered by snow on roads.

Mitigation for this could be to ensure road surfaces are gritted and kept clear in the event of significant snowfall.

Average winter rainfall

Average winter rainfall may increase by over 40% on today’s averages.

Impact 1

Erosion of earth bunds by prolonged heavy rainfall, reducing containment capability.

The mitigation for this would be to:

• increase inspection frequency of earth bunds during winter

• train personnel to identify signs of erosion

Impact 2

On-site flooding leading to:

• power failure
• process disruption
• infrastructure damage
• restrictions on site access for staff and emergency services

The mitigation for this could be to produce and maintain an on-site flood plan with reference to the guidance Preparing for flooding: A guide for sites regulated under EPR and COMAH.

Impact 3

Prolonged saturation of unmade ground resulting in soil movement and erosion and subsidence of cross-country pipelines leading to loss of containment.

The mitigation for this could be to increase inspection frequency of ground around cross-country pipelines to check for signs of:

• erosion
• subsidence
• hydrocarbon leaks

Impact 4

Bunds and tertiary containment fill up with rainwater, reducing the capacity for containing a spillage of a hazardous material.

The mitigation for this could include:

• providing level detection and alarms for bunds and tertiary containment
• implementing a frequent visual inspection regime during periods of high rainfall

Impact 5

Potential for contaminated floodwater or surface water run-off from the site, causing pollution.

The mitigation for this could include maintaining good housekeeping standards to make sure the ground and other surfaces do not contaminate floodwater.

Impact 6

Effluent treatment facilities could be overwhelmed with storm water, leading to direct discharge of untreated effluent to controlled water.

The mitigation for this could be to:

• segregate storm water from effluent drains, where practical
• provide suitable balancing capacity

Sea level rise

Sea level rise which could be as much as 0.6m higher compared to today’s level.

Impact 1

Increased risk of flooding of refinery process areas and associated impacts as previously identified.

The mitigation for this would be to prepare flood plan with reference to the guidance Preparing for flooding: A guide for sites regulated under EPR and COMAH.

Impact 2

Jetties become inaccessible (tide and wave height) or inoperable so raw materials cannot be delivered by ship.

Mitigation for this could include making sure contingency plans are in place for when ship access is not possible, such as:

• spare storage
• alternative land-based supply chains

Drier summers

Summers could see potentially up to 40% less rain than now.

Impact 1

Drought restrictions on direct and indirect abstraction, affecting the availability and quality of incoming water for cooling, boiler and process services.

The mitigation for this could be to implement and maintain a water efficiency management plan, including:

• minimisation at source
• rainwater harvesting
• options for effluent reuse

River flow

The flow in the watercourses could be 50% more than now at its peak, and 80% less than now at its lowest.

Impact 1

Longer periods of low water in estuaries, restricting access for shipping.

Mitigation for this could include making sure contingency plans are in place for when ship access is not possible, such as:

• spare storage
• alternative land-based supply chains

Impact 2

Poorer dispersion in receiving waters of large effluent streams.

The mitigation for this could be to provide buffer storage to hold effluent during periods of low fluvial flow.

Impact 3

Potential for inability to discharge when a watercourse is at high level, leading to effluent treatment inundation and failure.

The mitigation for this could be to review the effluent treatment design for its resilience to discharge at high water levels.

Storms

Storms could see a change in frequency and intensity. The unique combination of increased wind speeds, increased rainfall, and lightning during these events provides the potential for more extreme storm impacts.

Storms and high winds could damage building structures, jetties and tanks with increased potential for fugitive emissions.

Impact 1

Stability of tall and exposed structures such as tanks is at risk in stronger winds along with jetties with higher sideways loadings due to wave and wind action.

The mitigation for this could be to review design of tall structures, tanks and jetties to withstand higher maximum loading.

Impact 2

Increased risk of damage during major maintenance, such as to lifting equipment.

The mitigation for this could be to ensure increased wind speeds and gusts are adequately covered in risk assessments for crane-work.