Designing and monitoring landfills

Landfill engineering includes the design and construction of a landfill facility, as well as methods for checking the integrity of landfill facilities - for example, construction quality assurance.

GOV.UK guidance on landfill engineering

Monitoring landfill leachate, groundwater and surface water

Landfill leachate is a potentially polluting liquid, which may cause harmful effects to the soil, groundwater and surface water that surround a landfill site unless it is contained, managed and treated.

Your environmental permit will contain conditions that require you to put mechanisms in place to manage emissions from your site.

The reasons for monitoring leachate, groundwater and surface water at landfills are to:

  • demonstrate that the landfill is performing as designed
  • provide reassurance that leachate controls are preventing pollution of the environment (by reference to a pre-established baseline)
  • meet the control and monitoring requirements of legislation
  • demonstrate you comply with the groundwater control and trigger level requirements
  • indicate whether further investigation is required and, where the risks are unacceptable, the need for measures to prevent, reduce, or remove leachate pollution
  • identify when a site no longer presents a hazard to the environment or human health so that you can make an application to surrender the permit.

Monitoring landfill gas

Landfill gas is a complex mixture that mainly contains methane and CO2. These gases are produced during the major part of the decomposition process. Many other gases are produced in trace amounts and the exact composition of the gas will vary between different landfill sites, parts of the same site, and over time. You must monitor and control landfill gas.

Correctly monitoring landfill gas is important for the advance warning of any underground migration of gas out of a landfill, which might indicate that the control measures have failed. Landfill gas must also be collected and burned to produce energy or flared - this reduces the impact of methane on climate change.

Landfill stability

If your landfill site will accept non-hazardous or hazardous waste, you will need to assess hydrogeological, stability and landfill gas risks when you apply for your PPC permit. If your site will accept inert waste, you will need to assess stability risks. See the page in this guideline: Pollution prevention and control permits for landfill sites.

Further information

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