Comprehensive environmental data which includes hundreds of thousands of separate air quality readings taken continuously for more than a year has been published by shale gas exploration operator Cuadrilla today.
The company, which operates the UK’s most advanced shale gas exploration site in Preston New Road (PNR), near Blackpool, Lancashire, has posted the data on its website as part of its commitment to transparency and in line with its Environmental Management and Monitoring Plan (EMMP). This is in addition to a range of monitoring data already uploaded to Cuadrilla’s e-portal each month.
Independent specialists have been undertaking continuous air monitoring including recording methane and nitrogen dioxide levels continuously since the beginning of 2018. Independent monitoring was also carried out from February 2016 to January 2018 to establish a ‘baseline’ of levels occurring in the area.
There are hundreds of thousands of readings in total from each stage of the process including the drilling of the two wells and the hydraulic fracturing operations subsequently carried out between mid-October and mid-December 2018. Over the period the results show:
- During the ‘baseline’ period before site construction the BGS observed ambient methane levels of up to 70ppm. This formed the data set to monitor future operations.
- As part of the site’s environmental permit conditions, methane levels above 7.1ppm have to be notified to the Environment Agency. Methane readings above 7.1ppm are rare and the level is set purposefully low.
- There have been four separate instances of elevated methane levels recorded from PNR since May 2018 when a continuous methane detector was installed. Periods of elevated readings equate to less than 0.3 per cent of the time. The EA has been notified each time in accordance with the protocol.
- 99.7 per cent of the time the methane levels in and around the site have been below the reporting threshold of 7.1ppm – this includes the periods of operational activity including hydraulic fracturing and flaring.
- Three short term spikes of methane were recorded between 11 and 23 January, 2019. The highest spike was 30.5ppm which is less than half of the highest level recorded during the baseline period. This was a controlled release of methane through the flare during the well testing phase.
- The methane was mixed with nitrogen gas for a short period to form a non-combustible mix in the on-site flare. The flare pilot light was ignited to try and combust the mixture and propane was also added for the same purpose, but the methane and nitrogen gas mixture could not be burnt.
- The fourth instance of elevated methane emissions was in October when a reading of 12.1ppm was recorded for about 10 minutes. This related to methane gas in flow back water stored in tanks.
The continuous monitoring site forms part of a wide range of monitoring activity which is carried out at Preston New Road by Cuadrilla, as required by a range of regulators such as Lancashire County Council, the Environment Agency, Health and Safety Executive and Oil and Gas Authority. It was described by Lancashire County Council in December 2018 as “highly detailed and professional monitoring” which has made Preston New Road the most “monitored site in Europe”.
Nick Mace, environmental manager at Cuadrilla, said: “We are very proud of the extensive monitoring programme and the resulting data set being published today. It has worked exceptionally well and the data set is probably the most comprehensive ever gathered at a shale gas exploration site. It shows how seriously we take our environmental responsibilities at Cuadrilla.
“The absolute level of methane emissions over the 12 month reporting period is reassuringly tiny. While there were four instances of somewhat higher methane levels detected at Preston New Road, let me put these into context to reassure people. The instances were short in duration, very low in absolute volume and naturally occurring background methane at this level was also detected before the site existed, so it is not uncommon to see short term spikes in data.
“In addition, there are no health consequences whatsoever from very short term emissions of methane at these low concentrations.”
The on-site air quality monitoring is mirrored by the British Geological Survey (BGS) from a separate base about 450m from site designed to provide academic analysis and public reassurance.