TEP UK continued to enhance performance in relation to produced water discharges from its offshore operations. Improvements on the Produced Water Re-injection System on the North Alwyn platform have reduced the total mass of oil discharged in produced water under permit to just 1.1 tonnes in 2011. On Elgin-Franklin the average oil-in-water content was 13.6 milligrams per litre against a recommended level for the industry of 30 mg/l and an average concentration level across the UK Continental Shelf (UKCS) of 19.5 mg/l.
LOR benefited from the first full year of operating its new Sulphur Recovery Unit 3, enabling it to improve its sulphur recovery efficiency. The plant is part of a wider project to enable LOR to handle more sulphurous crude oil without detriment to the environment. In a further improvement LOR has introduced a de-sulphur dioxide additive in its fluidised catalytic cracking unit that will also have the potential of reducing SO2 emissions in future years. Emissions of SO2 in 2011 totalled 5,154 tonnes as against 5,227 in 2010 and 6,457 tonnes in 2009.
As a result of operational changes due to the reopening of a polyester plant (closed at the end of 2009) in order to help meet increasing demand, Bostik’s emission of aqueous effluent increased. While emissions at Leicester were within permitted limits, the overall level of Bostik’s chemical oxygen demand rose from 407 milligrams per litre in 2010 to 862 mg/l in 2011. Suspended solids rose from 92 mg/l to 259 mg/l over the same period.