ASSESSMENT OF CUMULATIVE IMPACTS ON RIVER GANGA FROM HARIDWAR TO GARHMUKTESH WAR WITH A SPECIFIC FOCUS ON POINT SOURCE DISCHARGES

Abstract

l'hcre were many schemes for pollution abatement of River Ganga. Ganga Action Plan (1 and 2) and thereaf'tcr NRCD and National Ganga River Basin Authority (NGBRA) launched by Government of India. But these plans focused only on big cities and did not take into account pollution generated in the entire stretch/catchment. In their efforts small cities, semi urban settlements. Industries and pollution from rural sector were not addressed. As a result program had limited success and the improvement in water quality of River Ganga was limited. l'he impact of' human activity or a project on an environmental resource or eco-system may he considered insignificant when assessed in isolation, but may become significant when evaluated in the context of the combined effct of all activities in the past, present, and foreseeable future that may have an impact on the resources. Thus it is necessary to assess the cumulative eflcts of pollution sources on river rather only assessment of each human activity and project in isolation. This study aims at studying the cumulative environmental impact assessment of point source discharges in river Ganga catchmcnt from I laridwar to Garhmukteshwar (160 km ) based on field visits satellite data supported with details from Survey of India topographical sheets, census data, district Industry data, water quality and discharge data. Catchment area of study stretch ol'river Ganga is about 5690 sq. km generating currently about 203 MID waste water out of which 117 MEl) is from urban areas and the rest ( 86 MLD ) is from rural areas. Near about 20 Ml.l) industrial waste water generates from various industries which lie in study catchment. Ihus total waste water generation from study catchment is about 223 ML!). Water samples collected from drains had been analyzed and studied for cumulative environmental impact assessment with water quality as one valued ecosystem component. Water quality model QUA!. 2K developed by EPA of United States was used for in stream water quality predictions of river Ganga stretch from Ilaridwar to Garhmukteshwar. Model simulation for the year 2034 shows that during non-monsoon period River stretch will he affected due to se crc degradation of' water quality (1301) >3 and 1)0 < 6 ) at various sites in the river stretch and would not ['ullill the outdoor bathing criteria. 41 Fnvironmental flow assessment using hydrological methods (modified tennat method and flow duration curve shifting method) revealed that in months of lean flow river flows do not meet the requirement of minimal flow required to maintain the river environment in desirable state. Impacts on flood plain valued ecosystem component as another V1iC was also studied.