Impacts of Untreated wastewater in Palestine
Impact of untreated wastewater on natural water bodies: Integrated risk assessment

Research

Study area: Wadi Faria, West Bank

Wadi Faria is a 320 km2 catchment draining the north-eastern slopes of the West Bank from Nablus to the Jordan River. The climate is arid to semi-arid, characterized by a dry and warm summer and mild and wet winter season. Precipitation input is highly variable in space and time with an estimated mean of 400 mm a-1. The Faria catchment is one of the most important agricultural areas in the West Bank. Surface runoff in the catchment is a mixture of (i) groundwater from springs, (ii) runoff generated from winter storms, and (iii) untreated industrial and domestic wastewater of the eastern part of the city of Nablus and untreated domestic wastewater of the Al-Faria refugee camp.

Location of Wadi Faria, West Bank © unesco-ihe

 

Groundwater as important source of drinking water

Groundwater is the most important source of drinking water in Palestine and all over the world and therefore it takes a central role regarding quantitative as well as qualitative aspects.

The protection of this important source of water is essential and is due to the long residence times in the groundwater a long-term assignment. On the one hand, the long residence times are important for the degradation and natural purification within the aquifer; on the other hand, groundwater has a long-term memory for resistant contamination. In order to avoid an extraordinary burden on the drinking water resources it is important to prevent this vulnerable system at the source of pollution.

Apart from leakages of the sewage system, the free flow and direct use of raw wastewater from domestic centers into the natural environment, diffuse pollution from cess pits, the extensive direct inputs from agriculture and particularly the linear inputs along rivers and streams from surface water play an important role regarding groundwater and drinking water quality.

Because of water shortage in semi-arid and arid regions wastewater is often reused. From a quantitative point of view, this is a useful measure to save water resources, but it demands a reasonable water quality of the reused water. This is not the case if persistent or non-degradable substances are not, or only with a high technical effort removed from the final effluents of sewage treatment plants.

Possible pathways for contaminants and possible risks for the population © unesco-ihe