Assessment of Groundwater Quality along the Cooum River, Chennai, Tamil Nadu, India

Table 8

Correlation coefficient (𝑟) for different water quality parameters—postmonsoon.

Parameter	pH	EC	TDS	BOD	COD	Na	Pb
2009 postmonsoon
pH	1
EC	0.3	1
TDS	0.412	0.975	1
BOD	0.348	0.88	0.899	1
COD	0.182	0.935	0.89	0.811	1
Na	0.399	0.915	0.948	0.909	0.808	1
Pb	0.084	0.832	0.78	0.676	0.827	0.748	1
2010 postmonsoon
pH	1
EC	0.363	1
TDS	0.445	0.972	1
BOD	0.405	0.884	0.921	1
COD	0.244	0.933	0.893	0.829	1
Na	0.333	0.846	0.886	0.809	0.762	1
Pb	0.186	0.849	0.808	0.747	0.857	0.781	1
2011 postmonsoon
pH	1
EC	0.392	1
TDS	0.325	0.974	1
BOD	0.310	0.914	0.892	1
COD	0.164	0.895	0.935	0.812	1
Na	0.363	0.879	0.843	0.818	0.730	1
Pb	0.167	0.821	0.846	0.723	0.853	0.734	1