Guidance on Mine Gas Risk Assessments

How do I know if a Coal Mine Gas Risk Assessment is required?

How do I know if a Coal Mine Gas Risk Assessment is required?

Use this Decision Tree to Identify what Risk Assessments you need for Planning Permission

Why do you Need a Coal Mine Gas Risk Assessment?

Gas ingress to residential buildings from mine workings can occur and potentially pose risks to human health.

Potentially hazardous mine gases can, in some instances, enter buildings (or other enclosed spaces) if the gases accumulate the levels can rise and present a risk to the property’s inhabitants.

The main gases of concern from old coal mines include:

  • methane
  • carbon dioxide
  • carbon monoxide
  • oxygen deficient air

Other gases such as hydrogen sulfide and radon may also need to be considered in specific sites where there are known issues. At Earth Environmental & Geotechnical we provide a comprehensive range of ground gas monitoring and surveys. We can make sure that the ground conditions and subsurface of your development site is clearly understood and any construction is designed to ensure the safety of those living and/or using the buildings.

Risk Assessments for Planning Permission

The starting point for all risk assessments is to complete a Phase 1 Desk Study ideally this should be accompanied with a site walkover.

You can read more about these services by following the links below.

Guidance on Mine Gas Risk Assessments.

If you are planning a new development or extending a property it is essential to have a thorough understanding of the ground conditions and what lies beneath your land or property.

If your development site is in a coal mining or mining risk area you will need to complete various risk assessments to ensure that you have assessed all risks and taken the steps required.

Our Decision Tree will help you identify what Risk Assessments you will need to ensure you supply the required documents to support your planning permission application. And make sure that you understand the correct design and constructions required to complete a successful safe project.

How Do I determine if a Coal Mine Gas Risk Assessment is Required?

The overall risk assessment process for mine gas follows the broad framework provided by the UK government on land contamination risk management (LCRM1) (Environment Agency, 2020). The Coal Mining Reporting Area (also known as CON29M Coal and Brine Consultation Areas) is the known extent of coal mining activity and is used to determine whether a coal mining report is required for property transactions and the conveyancing process.

The coalfield is divided into two areas, referred to as Development High Risk Area and Development Low Risk Area:

the High Risk Area (15% of the coalfield) is where coal mining risks are present at shallow depth which are likely to affect new development; and

the Low Risk Area (85% of the coalfield) is where past coal mining activity has taken place at sufficient depth that it poses low risk to new development.

If your development site is within a Coal Mining Reporting Area (as defined by the Coal Authority, based on their current data and experience across Great Britain2) then a mine gas risk assessment should be carried out.

What is the difference between a Coal Mining Risk Assessment and a Coal Mine Gas Risk Assessment?

  • A Coal Mining Risk Assessment will identify site-specific coal mining risks and set out the proposed mitigation strategy to show that the site can be made safe and stable for the proposed development.
  • A Coal Mine Gas Risk Assessment will identify if complex mine gas is a risk on your site and steps that need to be taken to minimise the risk.

What is a Coal Mining Risk Assessment?

The aim of a CMRA is to identify any coal mining legacy risks and set out a proposed mitigation strategy to demonstrate to the Local Planning Authority that the site can be made safe and stable for the proposed development. In some cases it may be possible to ensure that the development layout avoids recorded high risk features.

To find out more about Earth Environmental & Geotechnical’s Coal Mining Risk Assessments please click here

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