Lakes and Watercourses

TABLE 19.
CURRENT CONDITIONS: metals in sediment (mg/kg ds)
Class Description Cu Zn Cd Pb Hg
1 Very low concentrations ≤ 15 ≤ 150 ≤ 0.8 ≤ 50 ≤ 0.15
2 Low concentrations 15 – 25 150 – 300 0.8 – 2 50 – 150 0.15 – 0.3
3 Moderate high conc. 25 – 100 300 – 1000 2 – 7 150 – 400 0.3 – 1.0
4 High concentrations 100 – 500 1000 – 5000 7 – 35 400 – 2000 1.0 – 5
5 Very high conc. > 500 > 5000 > 35 > 2000 > 5
Class Description Cr Ni As
1 Very low concentrations ≤ 10 ≤ 5 ≤ 5
2 Low concentrations 10 – 20 5 – 15 5 – 10
3 Moderate high conc. 20 – 100 15 – 50 10 – 30
4 High concentrations 100 – 500 50 – 250 30 – 150
5 Very high conc. > 500 > 250 > 150
TABLE 20.
CURRENT CONDITIONS: metals in aquatic moss (mg/kg ds)
Class Description Cu Zn Cd Pb Hg
1 Very low concentrations ≤ 7 ≤ 60 ≤ 0.3 ≤ 3 ≤ 0.04
2 Low concentrations 7 – 15 60 – 160 0.3 – 1.0 3 – 10 0.04 – 0.1
3 Moderate high conc. 15 – 50 160 – 500 1.0 – 2.5 10 – 30 0.1 – 0.3
4 High concentrations 50 – 250 500 – 2500 2.5 – 15 30 – 150 0.3 – 1.5
5 Very high conc. > 250 > 2500 > 15 > 150 > 1.5
Class Description Cr Ni Co As
1 Very low concentrations ≤ 1.5 ≤ 4 ≤ 2 ≤ 0.5
2 Low concentrations 1.5 – 3.5 4 – 10 2 – 10 0.5 – 3
3 Moderate high conc. 3.5 – 10 10 – 30 10 – 30 3 – 8
4 High concentrations 10 – 50 30 – 150 30 – 150 8 – 40
5 Very high conc. > 50 > 150 > 150 > 40
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