On 21 December 2023, we issued an Enforcement Notice to the site operators at Hafod Landfill in Johnstown, Wrexham. This notice included several actions that needed to be taken to address the odour complaints reported between October and December 2023.

Our officers had previously identified parts of the Hafod Landfill site that were causing the odours. These findings came from investigations where our officers visited the site and carried out several offsite odour assessments at different times of the day.

The Site Operator has since complied with all steps outlined in the Enforcement Notice and completed several works, including the temporary capping of cells and the installation of pin wells to reduce the potential for gas emissions and odours. The Operator is also planning and carrying out additional work to improve the use of landfill gas and further reduce the chances of odours.

Our officers continue to ensure that the Site Operator meets the requirements of their Environmental Permit. We are also reviewing the Operator’s management procedures, and in September 2024 they provided us with an updated action plan.

Our officers also continue to complete offsite monitoring in response to incident reports and complaints by the local community.  

In September and October, we received several reports of odours in Johnstown. In response, our officers investigated the site and the surrounding area.

The operator recently completed a series of infrastructure improvements on site (see the update from the site operator below). During these scheduled works, officers detected some localised landfill gas and waste odours. However, these odours were not continuous and could not be detected once the works were completed.

The works included raising the height of leachate chambers (23/09/24 - 27/09/24) and installing new landfill gas collection pipework (08/10/24 - 05/11/24). These improvements are part of ongoing site development and are necessary to ensure landfill gas continues to be collected and utilised in the landfill gas engines.

We continue to carry out regular site inspections and offsite odour assessments to ensure the operator complies with the environmental permit.

Please be assured that Enovert is working tirelessly to ensure the best possible and most appropriate measures are used to prevent odours off-site. We are working closely with NRW on the actions we are taking.

Moving forward we will provide the local community with regular updates on developments and progress at the site, with a regular update provided via Natural Resources Wales. This is to complement the information already provided at the Community Liaison Meetings, which take place on a quarterly basis.

As part of this process, Enovert reports the following actions have been undertaken during September and October as part of scheduled site works:

• Further temporary LLDPE plastic liner was extended across the lower section of Cell 5b Western flank in early September 2024. This additional 3000 m2 of capping was installed to seal this inner flank prior to the development of Cell 5c next year.
• One of the main 180mm gas collection pipes has been relocated to the top of Cell 5b as tipping continues in this cell. All gas infrastructure in this cell has been reconnected to this main line which now sits on the permanent cap on Cell 5a, to ensure active extraction continues across this cell.
• A new 250mm gas collection pipe has been installed across a bench of Cell 5a and along the sidewall of Cell 5b. This effectively forms a ring main in this phase of the landfill, allowing gas to be extracted in two directions to minimise any vacuum losses across the entire system.
• Concrete leachate chambers raised in Cells 3 and 4. As waste height increases, with the normal infilling of the site, we need to correspondingly raise the leachate extraction chambers. Whilst we work on these, we deploy additional control measures as per our odour management plan, but some localised odours may be present whilst wells are disconnected from the gas system. Please be assured that this work is both necessary and completed in the shortest possible timescale.
• An engine rebuild within the Gas Utilisation Plant: a new engine has been purchased to replace the previous engine, which was due for a major rebuild based on hours in service. This new engine is expected to be commissioned within the next few weeks. During this work, gas extraction has continued to be managed via the second engine on-site and the high-temperature flare stack, which is specifically installed to ensure continuous and consistent extraction on the gas field during maintenance periods.
• We have trialled the use of a specialised methane (CH4) monitoring laser to assess for any point sources emissions on both the operational landfill and capped areas. The results can then be used to guide installation of further gas collection or temporary capping. The trial aims to compare the laser’s effectiveness against the usual equipment used for this type of survey and to determine if the results can improve gas capture.

Further works scheduled over the next few months will include:

• Installation of several sacrificial pin wells on the active area of Cell 5b.
• Installation of a new gas manifold in preparation for further gas extraction infrastructure on Cell 5b.
• Identify the location of new deep gas wells in Cell 5b, once waste levels reach final height.