TEMPORAL VARIABILITY ASSESSMENT OF MAJOR POLLUTANTS IN WASTEWATER OF HUDIARA DRAIN AND ALLIED AQUIFERS: A POTENTIAL ENVIRONMENTAL RISK

Abstract

Wastewater flowing through Hudiara Drain is posing serious threats to population, agriculture, livestock, and groundwater aquifers. No historical data was available regarding the drain water quality and its impact on groundwater in the allied areas. It is a nearly 100 kilometers trans-boundary Drain emanating from India with 55 kilometers reach in Pakistan where it finally falls into river Ravi. Some cattle died along its surroundings in 1998 and Directorate of Land Reclamation Punjab (now Water Resources Zone) Lahore was assigned to investigate. It reported that the Drain carries a cumulative load of more than three hundred industries and housing societies and that the aquifer below this it is directly linked with 27 villages containing As, Cu, Cd, Cr, Fe, Ni, Pb, Se, Zn, pesticides and various organic and inorganic matters which seems to be the major cause of various endemic and epidemics diseases including respiratory disorders, skin infections, gastrointestinal problems and even death in extreme situations. The current study involved eight years monitoring of this drain in which 240 samples of Hudiara Drain and 96 samples of groundwater were collected and examined during 2016-22 (Total: 336 Samples). Major water quality parameters like conductivity, total dissolved solids (TDS), chemical oxygen demand (COD), biological oxygen demand (BOD), Fe, Ni, Cu, Cr and Cd were determined for wastewater. The sodium absorption ratio (SAR) and residual sodium carbonate (RSC) were monitored to evaluate the irrigation water quality of the drain samples. The average values were computed, and it was found that the wastewater of drain was unfit due to high COD, BOD, TDS, Conductivity, Cu, Cd, SAR, and RSC during both pre- and post- monsoon seasons. Groundwater quality in the vicinity of Hudiara Drain indicated that all the physical parameters were within the fit range except Fe which exceeded the permissible limits. The groundwater quality regarding irrigation parameters revealed that its quality was fit for irrigation based on EC, SAR, and RSC. The temporal assessment of drain water did not provide a specific trend though a slow but steady deterioration in groundwater quality was observed. The groundwater was also found fit for irrigation quality in the whole area selected for study. An impact of wastewater on groundwater quality in adjacent areas was observed and a slow but steady increase in water quality deterioration was noticed which might be a potential threat in upcoming years keeping in view the high urbanization rate and water scarcity. Wastewater coming from industries and allied populations must be treated to avoid the increase in waterborne diseases.