Our report for NRW helps characterise the threat posed by coastal landfill sites to habitats and species in the Welsh MPA network

Flooding and erosion of coastal landfill sites can lead to physical and chemical contamination of the environment.

The release of landfill waste can be further exacerbated by the effects of climate change, such as sea-level rise and increase in extreme weather events, which can increase erosion rates and the likelihood of sea water inundation.

There are over 1,500 individual landfill sites recorded in Wales. Many of these are located at the coast and sit within or adjacent to Marine Protected Areas (MPAs), which contain habitats and species vulnerable to landfill materials such as asbestos, plastics, and inorganic and organic contaminants.

To inform the management of these pressures on the Welsh MPA network, Nature Resources Wales (NRW) commissioned ABPmer to identify the threat the coastal landfill sites could pose to the MPA network over different future time periods (epochs), and management measures that could reduce this threat.

Method

Coastal landfill sites were firstly identified based on landfill sites with potential to release waste to the marine environment due to coastal flooding or erosion.

The risk of waste being released from each coastal landfill site was then determined, our specialists characterised the sites based on several factors, including the potential level of flooding, susceptibility to coastal erosion, and the presence and condition of coastal defences.

The vulnerability of the MPA habitat features to waste being released from coastal landfill sites was then assessed. This was based on the potential pressures likely to arise from the different types of landfill waste, the distance at which the pressures could have an impact, and the potential sensitivity of features to each pressure.

These two stages were combined to determine an overall score for the threat each coastal landfill site poses to MPA habitat features.

This assessment was repeated for the three epochs: the present day (2005 – 2025), the medium-term future (2025 – 2055) and the long-term future (2055 – 2105), to identify the change in threat over time.

Results

Based on flooding and coastal erosion in the present day, 265 coastal landfill sites were identified as having the potential to release waste into the marine environment. This increased to 306 and 332 sites in the medium and long-term epochs, respectively.

It was also found that the landfill sites which had a higher risk of release waste tended to be in high flood risk areas, were undefended, and had a large seaward boundary that would be exposed to wave impact.

The highest concentration of coastal landfill sites occurred around the Dee Estuary, Burry Inlet, Swansea, Cardiff and Newport. The North West Operational Area and South Wales Operational Area (including the Burry Inlet) contained the highest proportions of coastal landfill sites which posed a high overall threat to MPA habitat features. These areas with high concentrations of coastal landfills and/or areas with landfills which pose a high overall threat to MPA features are considered a priority for further regional or site-specific investigations.

The habitat features deemed most at risk to the release of waste from landfill sites were estuaries and reefs. Sand influenced biogenic reefs, caves, mudflats and sandflats were also found to be at higher risk compared to other features.

Several management measures were found to have the potential to reduce the risk of released waste being released from coastal landfill sites. These include the removal of landfill waste, coastal protection, treating contamination, and inspection and surveillance.

Protected bird, fish and mammal species were not included in the main assessment, however, it was highlighted that they have the potential to be directly and/or indirectly impacted by both physical and chemical waste released from coastal landfill sites.

Next steps

NRW will use the report to prioritise further actions in areas which pose the highest threat to MPA habitat features. Priorities could include undertaking more detailed, site-specific investigations on the different parameters used to characterise the landfill sites, the transport of waste when released (based on coastal hydrodynamic processes), and the management measures currently implemented at the landfill sites. These further investigations will better inform the most appropriate management measures to implement going forward.

The complete findings are presented in a report, “Investigating the impact of landfill sites at the coast on MPA features in Wales”.

To download the full report, visit the NRW website.

^{Header image: Burry Port east beach fly ash landfill site, courtesy Harriet Robinson/NRW}

ABPmer routinely advises marine sectors on regulatory and policy matters and has a long history supporting government and its agencies in developing the evidence base against which policy decisions are made.

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