Physiochemical analysis of spring water used for drinking purposes in Northern Khyber Pakhtunkhwa, Pakistan

Abstract

Majority of the water supply schemes in the Northern Khyber Pakhtunkhwa have natural springs as source of water supply and utilizing it without any physical or chemical treatments except for primary sedimentation. The physiochemical characteristics of these rural sources of water supply are very little understood. This study primarily investigates the water quality of randomly selected springs located in Dir, Malakand, and Swat Districts to check the suitability of spring water for drinking purposes as per National Standards of Drinking Water Quality (NSDWQ) and according to World Health Organization (WHO) guidelines. Water samples from different springs were collected at different time interval and analyzed for physiochemical parameters. The concentrations of the parameters were compared with the NSDWQ and WHO guidelines.

Samples were analyzed for color, electrical conductivity (EC), odor, suspended solids (SS), total dissolved solids (TDS), taste, temperature (T), turbidity, pH, alkalinity, calcium (Ca⁺²), carbonates (CO₃^-), chloride (Cl^–), zinc (Zn⁺²), dissolved oxygen (DO), fluoride (F^–), iron (Fe⁺²), magnesium (Mg⁺²), manganese (Mn⁺²), nitrate (NO₃^-), nitrite (NO₂^-), sulfate (SO₄^2-), calcium hardness (CH), magnesium hardness (MH), andtotal hardness (TH). Variations from standard values were observed in Temperature (13.10 C to 21.30 C), Alkalinity (18.00 mg/L to 162.33mg/L), CO₃^-, (0 mg/L to 9.33 mg/L) and DO (5.60 mg/L to 12.60 mg/L). Also, Water samples of districts Swat and Dir were found compliant with NSDWQ and WHO guidelines, however, some of the parameters for Malakand district were higher but still under the acceptable thresholds. These includes T (21.30oC), SS (34 mg/L), Ca⁺² (75.88 mg/L), DO (9.870), CH (189.33 mg/L), and Zn⁺² (4.250 mg/L).