Groundwater Quality and Suitability Assessment in Tirupur Region, Tamil Nadu, India

Table 3

Classification of groundwater on the basis of EC, SAR, Na%, PI, MR, and Kelly’s ratio.

Parameters	Range	Groundwater class	Samples (n = 49)
			In. no	In%
Electrical conductivity (EC)	<250	Excellent	0	0
	250–750	Good	3	14
	750–2250	Permissible	13	62
	>2250	Unsuitable	5	24
Sodium adsorption ratio	<6	No problem	21	100
	6–9	Increasing problem	0	0
	>9	Severe problem	0	0
Sodium percentage (Na %)	<20	Excellent	1	4
	20–40	Good	16	76
	40–60	Permissible	4	20
	60–80	Doubtful	1	4
	>80	Unsuitable	0	0
Soluble sodium percentage (SSP)	<50	Suitable	19	90
	>50	Unsuitable	2	10
Residual sodium bicarbonate (RSBC)	<1.25	Suitable	16	76
	1.25–2.5	Marginal	2	10
	>2.5	Unsuitable	3	14
Permeability index (PI)	<60	Suitable	21	100
	>60	Unsuitable	0	0
Magnesium hazard (MH)	<50	Suitable	16	79
	>50	Unsuitable	5	24
Kelly’s index (KI)	<1	Suitable	18	86
	>1	Unsuitable	3	14