Site number	Mean ± standard error (mg∙L⁻¹)
Site number	Lead	Cadmium	Chromium
1	0.012 ± 0.000	0.002 ± 0.000	0.029 ± 0.008
2	0.015 ± 0.002	0.002 ± 0.000	0.022 ± 0.005
3	0.018 ± 0.003	0.002 ± 0.000	0.019 ± 0.004
4	0.021 ± 0.001	0.003 ± 0.000	0.036 ± 0.004
5	0.016 ± 0.001	0.003 ± 0.000	0.028 ± 0.004
6	0.016 ± 0.001	0.003 ± 0.000	0.034 ± 0.001
7	0.020 ± 0.003	0.004 ± 0.000	0.048 ± 0.004
8	0.013 ± 0.003	0.003 ± 0.000	0.018 ± 0.003
9	0.014 ± 0.001	0.002 ± 0.000	0.010 ± 0.001
10	0.013 ± 0.002	0.002 ± 0.000	0.024 ± 0.007
11	0.021 ± 0.001	0.003 ± 0.000	0.024 ± 0.006
Safe limit (mg∙L⁻¹)
CPCB*	0.1	2.0	2.0
FAO**	5.0	0.01	0.1
US EPA***	0.065	0.0018	Cr(III)	Cr(VI)
US EPA***	0.065	0.0018	0.570	0.016