The population of Gaza depends on groundwater as the only source for drinking, agricultural use, and domestic supply. The nearest stream is Wadi Ghazza to the south, sourced from Abu Middein along the coastline. It bears a small amount of water during the winter and virtually no water during the summer. Most of its water supply is diverted into Israel. The Gaza Aquifer along the coast is the main aquifer in the Gaza Strip and it consists mostly of Pleistocene sandstones. Like most of the Gaza Strip, Gaza is covered by quaternary soil; clay minerals in the soil absorb many organic and inorganic chemicals which has partially alleviated the extent of groundwater contamination.