Environment Report 2015

Figure 4 below shows that there has been a consistent decrease in the amount of NORM discharged with produced water since 2011, and the current values are the lowest since 2009. The average Ra 226 concentrations and the average total NORM concentrations are consistently and significantly below the 0.1 Bq/ml limit, both with a 2014 value of less than 0.003 Bq/ml.

1

Total NORM activity discharged is almost wholly dependent on the volume of produced water discharged. As an asset matures, there is potential for NORM scale to build up in pipework.

2

Figure 4: Breakdown of NORM Discharged in Produced Water

3

Pb (Lead) -210

Ra-226

Ra-228

Average Ra-226 concentration

Average NORM concentration

800,000

0.007

700,000

0.006

4

600,000

0.005

500,000

0.004

400,000

5

0.003

Bq/ml

300,000

0.002

200,000

0.001

100,000

6

Total NORM Activity Discharged to Sea (MBq)

0

0

2009

2010

2011

2012

2013

2014

Source: EEMS June 2015

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