Material

Example concentration (mg/kg)

Chromium

Mercury

Nickel

Coal ash/slag

1–200

Not reported

50–300

PP wash water sludge

< 1–10 000

0.1–3

28–20 000

FGD sludge

3–210

< 1–70

20–240

NPP decommissioning steel

3000

Not reported

2000

MSW ash/slag

200–2300

50

50–180

Oil refinery sludge

10–5080

2.1–4

40–2000

Limits*

70

5

1000

*Limiting concentrations for near surface disposal of wastes as calculated in Reference 17.

Notes: PP = power plant; NPP = nuclear power plant; FGD = flue gas desulphurisation; MSW = municipal solid waste.