Evaluation of groundwater quality in district Tando Muhammad Khan

Five samples of surface water were also collected from the canal passing through Tando Muhammad Khan District and Hyderabad District to compare the water quality of different water sources. Total of 96 locations were selected for groundwater sampling and 05 surface water samples were collected from Phuleli and Pinyari canals from different locations of two districts. The water samples were analyzed for pH, Electrical Conductivity (EC, Turbidity, Colour, Taste, Odour, Alkalinity as CaCO3, Bicarbonates (HCO3 Carbonates (CO3 Calcium (Ca), Magnesium (Mg), Hardness, Sodium (Na), Potassium (K), Chloride (Cl), Phosphate (PO4), Total Dissolved Solids (TDS) and Arsenic (As), Sodium Adsorption Ratio (SAR) and Residual Sodium Carbonate (RSC. The results indicated that 34.37 percent of the groundwater samples had bitter and salty taste and harmful both for human consumption and agriculture use, while 20.83 percent water samples had colour against WHO's pe rmissible limit (15 TCU). Similarly, 50 percent of the total samples had total dissolved solids beyond WHO's permissible limit (1000 mg/I), 54.16 percent underground water samples had chloride (Cl) levels beyond WHO's permissible limits (250 mg/l. The level of sulphate (SO4) also exceeded WHO's permissible limit (250 mg/l) in 44.8 percent underground water samples, while 38.5 percent determined water samples showed excessive amounts of calcium (Ca) which were over and above the WHO's permissible limits (75 mg/l). Sodium (Na) level in 54.16 percent collected samples crossed WHO's permissible limit of 200 mg/l, The level of Turbidity in 21.87 percent of samples exceeded beyond the WHO's permissible limits (5 NTU), while 21.87 percent groundwater samples had hardness more than permissible limits of 500 mg/l. Arsenic level in drinking water of various sources, particularly in third world countries has been one of the burning issues in the recent past because of its modified WHO's permissible limits (10 ppb) against earlier permissible limit of 50 ppb. Arsenic (As) is an inorganic element with no taste, smell, colour in water and it is a naturally occurring element found in soils, surface water and groundwater, highest in areas of geothermal activity. In the groundwater samples collected from different representative locations of Tando Muhammad Khan district, 35.42 percent samples had Arsenic level beyond the WHO's permissible limit of 10 ppb, which shows an alarming situation, and most of the samples with Arsenic beyond permissible limit reached toxicity level. However, odour, pH, magnesium (Mg) and potassium (K) in the groundwater samples were within unobjectionable limits for human consumption and agriculture use water. The Arsenic level in 13 groundwater samples collected from Tando Muhammad Khan taluka, 26 samples from Bulri Shah Karim taluka 23 samples from Tando Ghulam Hyder was within the permissible limit (10 ppb). However, the Arsenic level in 23 groundwater samples in Tando Muhammad Khan taluka, 10 samples from taluka Bulri Shah Karim and 01 sample from Tando Ghulam Hyder taluka of Tando Muhammad Khan district was beyond the WHO's permissible limit of 10 ppb and ranged between 25-500 ppb. In some of the groundwater samples, the Arsenic level crossed 250 ppb level and water samples collected from Tando Saindad of Tando Muhammad Khan taluka and Janan Soomro of Bulri Shah Karim taluka had Arsenic level up to 500 ppb.