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Appendix A: Contaminant analysis - Water Injection/Plough Dredging and Bed Levelling

Contaminant Analysis Required for Dredging Operations in the Thames

Water Injection Dredging/Plough Dredging/Bed Levelling

 

Determinand
Detection Limit
(mgkg-1 dry weight)
Analytical Technique/Notes
Note all fractions of a sample should be analysed
Organics
PAH Screen by HPLC
Total hydrocarbons
<100
 
Individual PAHS:
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluroanthene
Pyrene
Benzo (a) anthracene
Chrysene
Benzo (b) fluroanthene
Benzo (k) fluoranthene
Benzo (a) pyrene
Indeno (1,2,3-cd) pyrene
Dibenzo (a,h) anthracene
Benzo (g,h,i) perylene
<0.1
 
PCBs – ICES 7 Congeners
<0.02
If PCB contamination identified further analysis for individual congeners may be necessary.
Heavy Metals
Total metals should be analysed unless stated
Arsenic
<7
 
Cadmium
<0.4
 
Chromium
<40
 
Lead
<30
 
Mercury
<0.1
 
Copper
<18
 
Nickel
<20
 
Zinc
<124
 
Organo-metallic Compounds
Tri-butyl Tin & Di-butyl Tin
<0.1
 
Physical Properties
 
 
PSD (particle size)
Gravel, sand, silt fractions