Guidance

Landfill for hazardous or non-hazardous waste: 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

Greater potential for increased dust and odour or pests from daily activities.

The mitigation for this could be to:

• put a greater emphasis on regular updates from site operators
• review amenity management and action plans

Impact 2

There is potential overheating or failure of critical landfill gas pumps, control equipment and infrastructure.

Increased thermal expansion of landfill gas pipework resulting in movement which will induce stress and strain on wellheads. Possible increased risk of air ingress and condensate blockages due to low spots on pipework.

Overheating of landfill gas engines resulting in reduced efficiency and lower collection unless additional flaring is used.

The mitigation for this could be to:

• review procedures, maintenance and contingency plans

• make sure that adequate flaring capacity is available

Impact 3

Increase in hot waste, for example barbeque disposal, leading to waste fires on the tip face or within the waste mass.

The mitigation for this could be to:

• review waste acceptance criteria and waste inspection on receipt
• inspect the tip face before closure each day
• review fire incident procedures. Consider inert waste fire breaks to prevent rapid fire spread and stockpiling inert waste to use to smother fires
• review fire incident procedures and surface water management to ensure adequate supply of water for firefighting (see drier summers)

Impact 4

Desiccation or cracking of cover soils, leading to exposure of geomembrane or geosynthetic clay layers for example.

Exposure of engineered containment systems and caps to increased UV. This can result in a reduction in performance and can lead to increased infiltration, leachate generation and leakage and the risk of surface discharge.

The mitigation for this could be to make sure that engineered containment and capping designs are appropriate and are covered with suitable materials within appropriate timescales.

Impact 5

For restored areas and closed landfills, cover vegetation may be unable to survive leading to greater erosion risk.

The mitigation for this could be to review restoration plans and maintenance plans.

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

Higher winter temperatures could lead to increased odour complaints and pest infestations in spring and autumn.

The mitigation for this could be:

• to review leachate, gas odour and pest management plans
• greater public engagement
• advanced notice of changed or adverse weather conditions

Impact 2

Lower winter temperatures could lead to freezing of liquid carrier pipework. Freezing of condensate in landfill gas (LFG) pipework resulting in blockages and or reduced flow. Freezing of leachate in carrier pipework resulting in blockages and or reduced flow.

The mitigation for this could be to make sure that all critical pipework is adequately insulated.

Impact 3

Plant and equipment – it is possible for site vehicles to become iced to a base, particularly in wet conditions, and there is also a risk of diesel gelling.

Mitigations might include storing vehicles on hard standing ground or undercover.

Daily extreme rainfall

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

Impact 1

Potential for increased landfill leachate in operational cells, leading to failures of pumps and flooding of monitoring points.

The mitigation for this would be enhanced leachate management and storage infrastructure.

Impact 2

There is potential for overloading of surface water management system, leading to flooding or silt run-off to water. Increased accumulation of surface water run-off becoming contaminated and becoming leachate.

The mitigation for this could be to:

• make sure that surface water management plans are reviewed and systems are enhanced
• improve buffering and attenuation planting around site perimeter
• prepare flood plan with reference to additional guidance “Preparing for flooding. A guide for sites regulated under EPR and COMAH”

Impact 3

Could lead to temporary closure of landfills due to flooded access roads creating limited access.

The mitigation for this could be to:

• review haul road maintenance procedures and drainage capacity
• make sure enough aggregate is available to repair haul roads
• prepare contingency plan for temporary parking closure

Impact 4

Very wet waste in operational area generating landfill gas and hydrogen sulphide quickly.

The mitigation for this would be to:

• review operating procedures to ensure waste is adequately covered at the end of the working day
• make sure that adequate temporary or sacrificial gas infrastructure is installed in operational areas
• consider additional LFG infrastructure and flares to deal with ‘dirty’ LFG

Impact 5

Increased risk of erosion of cover soils leading to exposure and erosion of caps leading to increased infiltration, leachate generation and the risk of surface discharge.

The mitigation for this could be to ensure capping designs and materials are appropriate.

Impact 6

Increased risk of instability of cover soils to caps and soil protection layers to engineered containment systems leading to increased infiltration, leachate generation and leakage and the risk of surface discharge.

The mitigation for this could be to ensure engineered containment and capping designs are appropriate and are covered with suitable materials within appropriate timescales.

Impact 7

Increased risk of instability of waste mass leading to failure and damage to engineered containment systems.

The mitigation for this would be to:

• place waste to an appropriate gradient
• enhance leachate management and storage infrastructure

Average winter rainfall

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

Impact 1

This could lead to Increase in landfill leachate levels.

The mitigation for this would require enhanced leachate management and storage infrastructure.

Impact 2

There is potential for overloading of surface water management systems, leading to flooding.

The mitigation for this could be to:

• make sure that surface water management plans are reviewed and systems are enhanced
• prepare flood plan with reference to additional guidance “Preparing for flooding. A guide for sites regulated under EPR and COMAH”

Impact 3

Increasing operational difficulties (such as haul roads and access to tipping face).

Mitigations could include contingency plans and increased storage of suitable materials to maintain access.

Impact 4

Increased risk of erosion of cover soils leading to exposure and erosion of mineral caps leading to increased infiltration leachate generation and leakage and the risk of surface discharge.

The mitigation for this could be to make sure that capping designs and materials are appropriate.

Impact 5

Increased risk of instability of cover soils to caps and soil protection layers to engineered containment systems leading to increased leachate generation, infiltration and leakage and the risk of surface discharge.

The mitigation for this could be to make sure that engineered containment and capping designs and materials are appropriate.

Impact 6

Increased risk of instability of waste mass leading to failure and damage to engineered containment systems.

The mitigation for this would be to place waste to an appropriate gradient and enhance leachate management and storage infrastructure.

Sea level rise and coastal erosion

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

Impact 1

If a site is located near the coast there is potential for an increased risk of flooding.

The mitigation for this would be to:

• review flood defences around coastal landfill sites
• maintain and, where necessary, improve perimeter site engineering
• prepare flood plan with reference to additional guidance “Preparing for flooding. A guide for sites regulated under EPR and COMAH”

Impact 2

Increased salinity in the waste mass which may change the mobility of contaminants.

The mitigation would be to:

• review flood defences around coastal sites
• to maintain, and where necessary, improve perimeter site engineering

Drier summers

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

Impact 1

Potential increase in odours and amenity issues such as fly infestations, impacting on local communities.

The mitigation for this could include:

• enhanced management plans from site operators
• more frequent review of amenity impact and plans
• customer engagement
• ongoing proactive monitoring

Impact 2

Increase in airborne dust and reduced air quality for local receptors, for both residents and businesses.

The mitigation for this would be to make sure that:

• cover is applied at the end of the working day
• caps are protected and sites restored

Impact 3

There is a risk of desiccation of the landfill cap, leading to increased gas emissions, infiltration, leachate generation and leakage and the risk of surface discharge.

The mitigation for this would be to make sure that capping designs and materials are appropriate and are covered with suitable materials within appropriate timescales. and sites restored.

Impact 4

Less surface water available to use for dust suppression and tackling fires.

The mitigation for this would be to make sure that there is sufficient surface water storage capacity on site.

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

There is potential impact on volumes permitted in discharge consents to local watercourses in both high and low flows where limited dilution would be provided.

The mitigation would include reviewing and varying permits and discharge consent limits to avoid environmental impact or flooding downstream.

Impact 2

Increased risk of erosion of site sidewalls or inundation of waste by higher river levels or flood water.

The mitigation for this would be to:

• maintain, and where necessary improve perimeter site engineering
• install bunds