Air quality near Third Energy’s gas site in North Yorkshire deteriorated as the company mobilised equipment and got ready to frack, research has revealed.
Monitoring at the site at Kirby Misperton saw a significant rise in levels of nitrogen oxides (NOx) pollutants, which coincided with increases in lorry movements and the operation of diesel-powered machinery.
The air quality changed from that typical of a rural setting to what you would expect in an urban area.
The study was carried out by University of York researchers as part of a project coordinated by the British Geological Survey. The findings reflect a conclusion of a report by the government’s Air Quality Expert Group. This estimated that UK shale gas extraction could lead to increases in NOx emissions of 1-4% of 2012 the national total.
Third Energy said its environmental statement had expected increased emissions when the Kirby Misperton site became operational but it said the increase had not breached air quality limits. Full statement and other reaction to the report here
Significant increase in exhaust emissions
The data from the Kirby Misperton monitoring project for 2015-2017 shows that NOx levels at Third Energy’s site, known as KM8, did not exceed national air quality thresholds at any point. But in the second half of 2017 the annual concentration increased significantly.
According to the report:
“There was a noticeable increase in NOx from Autumn 2017 as the site was prepared for hydraulic fracturing operations to begin.
“From 19th September 2017, the monitoring changed at the KM8 site as Third Energy started to bring equipment on to site.
“This led to a greater number of vehicle movements to, from and on the site, and in the local area. In addition to equipment being brought to site there was also an increase in traffic associated with the local protests and policing.”
The research also pointed to the installation and operation of on-site diesel generators as a reason for the increase.
The report said:
“These activities changed the emissions at KM8 and marked the end of the baseline period when activities at the KM8 site and locally were relatively benign.”
Third Energy had expected to begin fracking in about November 2017. But after all the equipment was deployed, the government delayed granting hydraulic fracturing consent. This was firstly because of a legal loophole and later when ministers ordered a financial resilience assessment on Third Energy.
So far, the consent has not been granted and Third Energy cleared the site by spring 2018. This was also reflected in the air quality data.
The report said:
“From the 1st March 2018, the removal of equipment from the site was commenced as operations were suspended, without hydraulic fracturing taking place, following continued delay in receiving final approval to carry out hydraulic fracturing. As a result of this, patterns in air quality again started to change as the site returned towards a more benign state as was the case during the baseline period.”
The researchers’ conclusions were also supported by important changes at Kirby Misperton in the level of two constituents of NOx: NO and NO2.
A major source of NOx in the UK is road transport. NO is emitted by exhaust pipes and turns into the secondary pollutant NO2, following oxidisation.
In 2016, NO2 was in higher concentrations than NO and made the most significant concentration to NOx recorded at the Kirby Misperton monitoring station.
The report suggests that this was because the monitoring station was on the edge of the fracking site and quite some distance from the nearest main road. The air that reached the monitoring equipment had time for the NO vehicle emissions to oxidise into NO2.
But in September 2017, the trend reversed. NO began to dominate the NOx. This indicated a change in the source of emissions and coincided with the increased activity at the site. The NO vehicle emissions did not have time to oxidise into NO2 before they were picked up by the air monitoring equipment.
The researchers concluded:
“it does indicate that the characteristics of KM [Kirby Misperton] site changed significantly as a result of the preparations being made for hydraulic fracturing-related activities.
“In terms of the impact on residents living in Kirby Misperton, these plots would suggest that after September 2017 (and until end of February 2018) the levels of NOx pollution at the site were more similar to living in an urbanised area, rather than a rural setting with only a few major roads and industrial sources.”
The report added:
“This highlights the importance of measuring the whole shale gas operational cycle for air quality as the preparative operations can have a substantial impact on air pollution.”
The latest results also point to potential long-term fugitive emissions of methane (CH4) from the Kirby Misperton gas site or its infrastructure.
The researchers said there were spikes of high concentrations of methane, at more than five times background levels, over short periods of time. This happened mostly when there was a light south-south easterly wind and was accompanied by little change in the levels of carbon dioxide (CO2). This indicated the presence of a non-combusted fugitive methane source in the local area, the researchers said.
The report concluded:
“Given that the existing Third Energy well-head is positioned about 100 m upwind from the measurement site in this direction, we suggest that these enhancements may well represent detection of fugitive emissions of CH4 from the existing conventional gas extraction site, which appear to be a continuous feature across both baseline periods.”
“These episodic features are worthy of further case study attention during any operational phase and may represent a local fugitive emission source, such as the existing Third Energy conventional gas site and well-head.”
The researchers identified other potential sources of fugitive methane: landfill sites at Knapton and Caulklands, Pickering gas offtake station and four local gas leaks.
The Kirby Misperton monitoring also recorded low levels of hydrogen sulphide gas (H2S), which smells like rotten eggs. The average level was 1.1 parts per billion (ppb) but on occasions it rose to 22 ppb. This is well below any exposure limits that would affect health, which are measured in parts per million. But the report said:
“Odours have been reported in the village. The dataset has therefore been analysed to try and identify any sources of enhanced H2S, and whether these may explain the reported odour incidents.
“These peaks may not be due to operations at KM8 but may be due to work being conducted on conventional gas wells to the south and west of the site.”
Preston New Road
The York University team has also monitored air pollution at Cuadrilla’s site at Preston New Road, near Blackpool.
According to the report, the results were largely similar in 2017-2018 than in 2016-2017.
Monitoring identified sources of NOx to the south east of the monitoring site, which was probably from traffic on the A583 Preston New Road, the report concluded. NOx and particulate levels were highest on weekdays and in the morning and evening, coinciding with traffic rush hours.
But the report added:
“There is also a strong source [of NOx] directly west of the [monitoring] site. This source was not observed in the previous Phase 2 data (2016-2017) and is most likely due to the developments taking place at the Preston New Road site to the direct west of the monitors.
“Currently this is not having the same scale of effect on concentrations as has been observed at KM in autumn 2017.”
The report also noted there was a large source of particulates to the south east of the monitors, recorded in both 2017-2018 and 2016-2017. This was determined to be a local influence, it said.
On methane emissions, the report identified sources at two local dairy farms and gas leaks from the distribution network. It added:
“There was no detectable evidence of significant emissions to atmosphere from the PNR2 well that was being drilled during period covered by this report.”
“Key to public acceptance”
The report concluded that 12 months of monitoring was enough to give a baseline picture against which any changes seen following fracking could be compared.
“Credible and transparent monitoring is key to gaining public acceptance of the evidence base on the industry’s environmental and public-health impact.”