Failed waste stream audit – handling not in line with waste management plan - December 7, 2017

Between the 07/12/2017 and 09/03/2018 a Waste Stream Audit for the main waste categories produced at the Preston New Road Exploration site was carried out by the Environment Agency and found that:

The Waste Management Plan requires drill cuttings to be separated from the drilling mud, as far as reasonably practicable, at the surface, so that the maximum amount of drilling mud can be reused on site. The amount of spent fluid drilling muds produced on site is significantly higher than the Waste Management Plan estimates (i.e. over 2500 m3already produced per well compared with the total estimate of 400 m3/well). We recommend improvements are made to the efficiency of the separation process, if this is not possible a change is required to the Waste Management Plan.

According to Waste Management Plan waste spacer fluid and suspension brine should be collected on site as separate fractions (i.e. estimated suspension brine 20-40 m3/well and spacer fluid 20-40m3/well). During the audit, duty of care notes for offsite dispatch of waste described as spacer fluid or suspension brine were not available. These
CAR 2 V2.0Page 3of 5wastes were removed from site described as spent fluid drilling muds and/or as returned slurry cement waste. Please ensure waste spacer fluid and suspension brine are collected and managed separately, not mixed into other waste steams.

Approximately 56 loads of extractive waste removed from site were described by the subsequent waste holders as having an unexpectedly high water content (i.e. 90% or more). A explanation was provided for the high water content, for example the artesian flow of groundwater at the commencement of drilling the shallow conductor for the first well in June 2017, water from the cellar that requires removal following rainfall, and bund water from static and mobile tanks around the rig. Waste’s high water content and the reason for it were not explained in the consignment notes and waste transfer notes, greater clarity on the description of the activity that gave rise to the extractive waste would prevent confusion.