Of 166 wells operating in 1980, only 96 were still in operation as of 2011; contaminants are industrial in origin.
By Zafrir Rinat
Almost two thirds of drinking-water wells in the greater Tel Aviv area have been declared too contaminated for use, according to a recent study.
The data, collected by the Health Ministry and the Water Authority, show that in 1980 there were 166 wells, fed by the coastal aquifer, which provided a good deal of the drinking water to the big cities in the Tel Aviv area. As of the end of 2011, 96 of them were out of operation, mostly because of contamination. The contaminants are industrial in origin, particularly from armaments production, use of fertilizers and pesticides, and contaminated sludge seeping into the ground.
Another source of pollution is the salination of the water table, which happens when too much sweet water is pumped out and is replaced by sea water. According to the Health Ministry and Water Authority figures, 32 of the wells were declared unfit for use due to a high level of nitrates, which originate in chemical fertilizers, and some of those were also found to contain toxic metals.
Eight other wells were also found to contain toxic metals. Ten wells were disqualified for containing perchlorate, a component of rocket fuel used in military manufacturing, large quantities of which leaked into the ground from the Israel Military Industries site in Ramat Hasharon.
The use of well water was completely stopped in Ramat Hasharon due to perchlorate contamination, and the city now gets its water from the National Water Carrier.
Ramat Hasharon has filed suit against the state due to the expenses it has incurred in building infrastructure to receive water from the National Water Carrier. It is believed that some 600 million cubic meters of water in the Ramat Sharon area are contaminated.
It will have to be pumped and purified, which will take 20 years and cost about half a billion shekels. If this is not done, the contamination will continue to spread, putting more groundwater at risk.
In the industrial zone of Holon, seven wells, producing some 124 million cubic meters of polluted water in an area covering 2.8 square kilometers, have had to be closed due to pollution.
Last year the Water Authority checked seven more wells in Bnei Brak, Tel Aviv and Ramat Gan, and found two of them to be contaminated. The Water Authority plans to rehabilitate the wells in the area of Tel Aviv once occupied by Israel Military Industries.
These plans include, in addition to pumping and purifying water, injecting materials into the aquifer that help dissolve the contaminants more quickly.
Contaminated wells next to 20 gas stations in the area have been cleaned up, and materials speeding up dissolution of contaminants have been injected into a contaminated area on Yigal Alon Street in Tel Aviv, which the Water Authority says has reduced the contamination there.
http://www.haaretz.com/print-edition/news/study-finds-most-tel-aviv-area-wells-too-polluted-to-draw-drinking-water-1.407880