USGS hardness (Handa 1964) shows four categories of hardness: soft, slightly hard, moderately hard and very hard.
The analytical data indicate that 48%% surface water samples are moderately hard and 36%% are of hard categories, while 16%% water samples have hardness higher than 300 mg L−1, which is the desirable limit for drinking purposes (Fig. 5).
Their wood is light, moderately hard, and very durable in contact with the soil but is usually knotty and has an odour sometimes considered offensive.
In Cretaceous, 16%% of the samples are in the slightly hard category, 52%% in the moderately hard and 32%% in the very hard category.
However, 18.8 % each of the groundwater samples were moderately hard and hard, while 20%% of the surface water samples were moderately hard.
Based on the Total Hardness (TH) and Electrical Conductivity (EC) values the water samples were found soft to moderately hard and fresh water, respectively.
Sawyer and McCarty (1967) classified groundwater, based on TH, as ground water with TH <75, 75 150, 150 300 and >300 mg/l, designated as soft, moderately hard, hard and very hard, respectively (Table 3).
Sawyer and McCarthy (1967) classified groundwater, based on TH, as groundwater with TH <75, 75 150, 150 300 and >300 mg L−1, designated as soft, moderately hard, hard, and very hard, respectively.
Hardness of the water samples also varies among moderately hard, hard and very hard (from 50 in sample 27 to 505 sample 20) precluding the use of the water for drinking, domestic or irrigation purpose.
According to Sawyer and McCarty, 1967, the water samples have been classified as soft, moderately hard, hard and very hard as mentioned in the table above.
Generally, water sources with TH values of (0 75), (>75 150) (>150–300) (>300) were classified as soft, moderately hard, hard, and very hard, respectively (Kaka et al. 2011).
