To assess the impact of seasonal trends on groundwater quality, samples were collected during pre-monsoon, post-monsoon, spring and winter seasons from selected locations of Itawa tehsil of Kota District of Rajasthan state (India) from 2011 to 2013 and determined physicochemical parameters like pH, TDS, specific conductivity, total alkalinity, magnesium, nitrate, sulphate, phosphate, potassium, sodium, hardness, chloride, and fluoride. Standard research techniques were used to evaluate the quality of groundwater and its suitability for irrigation and drinking purpose. Results of investigation showed that conductivity, alkalinity and hardness parameters have higher values during the post-monsoon season than in the spring season. The average values for groundwater in pre-monsoon, post-monsoon, spring and winter seasons of the pH was 7.3 - 8.1, EC (Electrical Conductivity) 910 - 1313 µs/cm, TDS (Total Dissolved Solid) 659 - 911 mg/L, TA (Total Alkalinity) 205 - 407 mg/L, TH (Total Hardness) 120 - 312 mg /L, Ca (Calcium) 79 - 185 mg/L, Mg (Magnesium) 43 -125 mg/L, Na (Sodium) 109 - 183 mg/L, K (Potassium) 5 - 11 mg/L, Cl (Chloride) 54 - 107 mg/L, SO42- (Sulphate) 64 - 125 mg/L, NO3- (Nitrate) 19 - 41 mg/L, PO43- (Phosphate) 0.28 - 0.55 mg/L. The results were compared with the World Health Organization (WHO, 2006) guideline limits for drinking water1. The study suggested that the majority of the groundwater samples were unsuitable for irrigation in post-monsoon compared to that in pre-monsoon.
