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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.
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.
Figure 4: Breakdown of NORM Discharged in Produced Water
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
2009
2010
2011
2012
2013
2014
Bq/ml
Total NORM Activity Discharged to Sea (MBq)
Pb (Lead) -210
Ra-226
Ra-228
Average Ra-226 concentration
Average NORM concentration
Source: EEMS June 2015
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