Update from the UKHSA and Environment Agency
The Head of Unit UKHSA provided a detailed report and presentation relating to the health risk assessment for Walley’s Quarry Landfill Site. He advised that the odours within Silverdale and the surrounding areas continued to be a complex and long running incident for UKHSA.
The Chairman welcomed the quality of the assessment and data in the report and presentation which was based on the monthly UKSHA risk assessments of the site. The report considered air quality data and health data going back to the inception of this incident and presentation slides further detailed the position of the mobile monitoring stations around the Landfill Site and data from the monitoring stations.
The Committee noted that high concentrations of hydrogen sulphide (H2S) were first recorded in March 2021, levels of H2S had decreased monthly towards December 2021 and at that time there was anticipation that the measures put in place were having the desired effect. However, UKHSA informed Committee that increases in concentration of H2S were recorded in December 2021 and January 2022 with the highest concentrations of H2S recorded at station MMF9 located in the Galingale residential area. This had raised new concerns that some of the measures on site were not continuing to have the desired effect. UKHSA reported concern for the toxicological effect on individuals’ physical health and also the psychological effect on residents. It was explained that only the Environment Agency (EA) could determine the effectiveness of the interventions on the site.
It was explained that from January 2022 onwards, UKHSA was only comparing the monitoring results with the United States Environmental Protection Agency long-term (lifetime) health based guideline (2 µg/m3).
• (MMF1 and MMF2) concentrations were below the long-term (lifetime) health based guidance value, as they have been since June/July 2021
• (MMF6) concentrations have been below the long-term (lifetime) health-based guidance value since July 2021, In January 2022, showed a slight exceedance; the overall cumulative average is below the long-term (lifetime) health-based guidance value
• (MMF9), concentrations in January 2022 remained above the US EPA RfC. In this location concentrations were also above the World Health Organisation(WHO) odour annoyance guideline value for 16% of the time.
At MMF9, located in the Galingale residential area, concentrations had remained above the recommended guideline value for the duration of the incident and currently, whilst any risk to long-term (lifetime) physical health is likely to be small, UKHSA could not exclude long term health impact if they remained so.
The Committee noted the following comments and responses to questions:
· Data measurement – concerns were raised that monitoring data would not show seasonality without a full year monitoring data. Assurance was provided that monitoring data went back to March 2021 and would be in place until December 2022 and there would be more than a years’ worth of data to compare.
· Concerns were highlighted about H2S concentration levels at MMF9 in the residential area and the health impact on people who lived there. Psychological impact, although not in the risk assessment of air quality data, was also being taken into account. The figures did not show that the remedial work going on to date had been successful.
· Levels of other substances monitored on the site were not of concern at this time from the data presented.
· UKSHA could not respond to questions about the effectiveness of remedial work on site, the EA had provided a briefing paper on regulatory action taken to date, the latest measures to improve control of H2S emissions and a link to the plan to reduce H2S emissions from Walley’s Quarry. UKHSA could only interpret the EA’s monitored levels of H2S concentration coming off site. The only way UKHSA could determine if the work was effective was if levels fell in the monitoring data provided by EA.
· UKHSA had seen evidence of levels decreasing and had seen some differences caused by atmospheric conditions, but essentially EA was responsible for monitoring concentrations outside of the site and provided monitoring data to UKHSA. UKHSA was independent of the EA rather than contracted to the EA.
· Concern was raised about the impact of materials deposited in the landfill site on the water course. It was confirmed that the EA was responsible for monitoring the water and had a duty to make UKHSA aware of any issues. At this time no concerns had been reported.
· Members stressed that residents across Staffordshire had suffered long enoughbut there was no clear point of resolution for residents. Committee were advised that residents continued to be extremely annoyed about the odour, the impact on them, and that the situation had gone on for over 15 months. Residents continued to report a range of problems - foul odour, headache, nausea and respiratory symptoms irritation around eyes and throat which correlated with HS2 concentrations. Mechanisms were in place for residents to report symptoms.
· Committee heard that in autumn 2021 Public Health was reasonably optimistic that there was a clear improving trend, but now were not confident having seen a spike in levels of H2S on the site. There was concern that there was not a clear plan to assure residents of what was promised to them in Parliament a year ago and concerns to the health of residents as the incident endures.
· Committee was assured that NHS had set up a dedicated mental health support facility and residents could access support and advice on health issues through their general practice GP.
· Activity on the site was due to end in 2026 when the contract ended, monitoring of the landfill site would have to continue even when activity ended, and the site was capped. Remediation of the site would be part of any Government action.
The Chairman thanked representatives from UKHSA and Dr Richard Harling for presenting the updates and for responses to questions at the meeting.
The Chairman summarised that the incident at Walley’s Quarry had been an ongoing matter, since 2020, this committee had met in July 2021 to discuss the health implications and residents were still looking for a resolution to the problem in March 2022. The committee had heard that the longer this incident goes on, without a timeline to resolve the issue, the risks to long term health because of H2S concentrations could not be excluded and there was an impact on residents’ mental health. The committee stressed the need to send a clear message to the Government for a decisive and urgent solution to the problems at Walley’s Quarry Landfill Site, with the concentrations of H2S escape and in the absence of a clear plan there was a need to discontinue operations and close the site.