Table 5 Average metal concentration and their ranges in water samples collected from Rivers and Channels used to irrigate Awara Melka and Nura Era Farms (mean ± SD, n = 4)

Awara Melka

Bulga river

20.8 ± 0.2

13.3 ± 0.4

28.0 ± 0.1

11.8 ± 0.1

0.038 ± 0.001

0.024 ± 0.001

0.026 ± 0.001

0.068 ± 0.001

ND

0.0043 ± 0.001

Channels

 Mean

28.3 ± 0.3

15.1 ± 0.4

38.4 ± 0.1

12.5 ± 0.6

0.036 ± 0.004

0.046 ± 0.005

0.022 ± 0.002

0.080 ± 0.004

ND

0.0075 ± 0.0003

 Range

26.9–29.0

11.1–24.3

22.2–34.4

8.3–17.4

0.032–0.037

0.043–0.048

<0.001–0.037

0.062–0.096

ND

0.0073–0.0078

Nura Era

Awash river

14.9 ± 0.2

13.2 ± 0.6

26.9 ± 0.1

6.7 ± 0.1

0.142 ± 0.012

0.037 ± 0.002

0.092 ± 0.002

0.106 ± 0.002

ND

ND

Channels

 Mean

16.3 ± 0.5

15.2 ± 0.6

28.6 ± 0.4

6.8 ± 0.2

0.352 ± 0.011

0.044 ± 0.005

0.061 ± 0.005

0.090 ± 0.006

ND

0.0070 ± 0.004

 Range

12.8–18.8

12.7–19.7

22.0–33.1

5.8–8.0

0.124–0.709

0.011–0.066

0.012–0.184

0.053–0.125

ND

<0.0001–0.0091