A slew of water treatment plants has greatly reduced Israel’s dependence on rainwater. But desalination may also be adversely affecting the environment and people’s health.
Zafrir Rinat Feb 06, 2017
Israel has pumped increasing quantities of water from the Mediterranean Sea in recent years. The series of desalination plants built along the coast is supplying a significant amount of water to the country’s homes, relieving Israel of the chronic water shortages it once endured.
But the new installations have also brought new problems, such as the accumulative effect of large quantities of salt being dumped back into the sea as a by-product of the desalination process.
This question has already led several government ministries to order a study of the issue, which is already underway. Ensuing health and environmental problems will also have to be addressed.
This year, the country’s fifth desalination plant goes online in Ashdod. Along with the four older plants, some 582 million cubic meters of water will be produced annually – meeting about two-thirds of Israel’s domestic needs. It will not be the last plant, though, with the Israel Water Authority planning to establish another in Western Galilee and another four large facilities along the coast by 2025. Zoning plans for these coastal projects have already been approved.
“Desalination has created a new and reliable source of water, and reduces dependency on the amount of rainwater,” said Hila Gil, director of the desalination division in the Water Authority. “It allows us to allocate water for farmers for a much longer period, and also for rehabilitating natural parks,” she added.
It’s easy to see the effect it is having on agriculture. A study by the agricultural administration, in conjunction with a consortium of government and academic institutions, found that in the years 1992-2011, the concentrations of salt in the leaves of citrus orchards was high, putting the plants at risk. But last year, a study found a decline of dozens of percent in salt concentrations, as a result of increased use of desalinated water.
“Desalination has significantly improved the quality of the water,” said Gil.
The dramatic influence of desalination plants on the balance of supply and demand for water can be seen in the Kinneret Basin, in northern Israel. No desalinated water has been supplied there as yet, and its supply is dependent solely on rainwater and natural supplies such as deep wells.
In recent years, there has been a shortage of rain there and the Water Authority has had to set quotas on quantities of water supplied to farmers. But the damage to the region, and Lake Kinneret in particular, could have been greater.
Using desalination plants as a backup, the country can afford to completely stop pumping water from the Kinneret and National Water Carrier (which originates in the north and was once the main provider of water to the center of the country). This will prevent a more severe drop in the lake’s water level.
Alongside the advantages, desalination plants have also had a significant impact on the environment and, indirectly, on consumer health.
Although they supply high quality water, it is devoid of some key minerals found in normal water, like magnesium. Magnesium shortages can raise the risk of heart disease, with some experts pointing to a significant shortage of this important mineral in the water.
“Initial results of Israeli studies point to an elevated mortality risk of myocardial infarction in areas where there is wide use of desalinated water,” said public health expert Prof. Yona Amitai, speaking recently at a Bar-Ilan University conference on regulating water supply.
Amitai urged that “more studies be done to examine the possibility of adding magnesium to the water.”
As well as being bad for people, magnesium deficiency can also hurt agricultural products. Researchers at the agricultural administration have already found a significant drop in the supply of this mineral in orchards where desalinated water is used. However, they said the problem can be overcome by adding fertilizer containing magnesium to the water.
“We are in the process of choosing a company that would tell us how to check the possibility of adding magnesium to the water,” noted Gil. “There are varying estimates regarding the expense of such an additive. There is no established information or survey from which we can tell how necessary or efficient this would be.”
She said that even if it transpired that there was a need, “it might cost hundreds of millions of shekels a year. It could affect the price of the water, and we would be the ones who’d have to explain to the public why the prices have risen.”
Desalination plants consume vast amounts of energy, and producing the electricity to power them pollutes the air. But Gil said they account for only a small percentage of the electricity used in Israel. Besides, she noted, air pollution isn’t what worries environmentalists, but pollution of the oceans from the flow of wastewater from the desalination process, which contains high concentrations of salt. This also contains the various chemicals used to treat the water. Gil said routine follow-up is done on the effects of salt concentration, and until now it has been seen as having only a localized effect.
This is the sort of water technology most often associated with Israel: At the IDE and Veolia Sea Water Reverse Osmosis Desalination Plant in Ashkelon.
A seawater desalination plant in Ashkelon.Eitan Simanor / Alamy Stock Photo
Another concern regarding desalination plants is the risk of becoming too dependent on them. One document compiled by a conservation group recently found that the plants can be sensitive to emergencies in the vicinity, such as an oil spill. The membrane technology inside the plants – which separates the salt from the water – cannot handle this type of pollution and can be badly damaged as a result. Proof of this came just a few weeks ago, when oil from one of the Electric Corporation’s installations in Ashdod leaked into the sea. Afterward, the Health Ministry ordered three of the desalination plants to immediately suspend operations.
But government ministries believe further study is required to see what the accumulative effect is from all of the installations.
A study is currently underway at the Israel Oceanographic and Limnological Research Institute in Haifa. Dr. Jack Silverman, one of the researchers involved, says they are trying to assess what effect the high salt concentrations will have on wildlife at the bottom of the sea.
“Along the bottom, there are very important processes that go on with respect to the survival of the ecological system,” he noted.
“Our working assumption is that the concentration may influence these processes and, according to the initial findings, there is an effect,” he said.
“It’s not the desalination that’s the problem,” the Water Authority responded. “It is one of the solutions for adding to the water supply, which also allows for rehabilitating aquifers in terms of quality and quantity.”
So far, desalination plants have been built with almost zero public opposition. But the situation is different in the case of the plant planned for Western Galilee.
Residents there are campaigning against having a desalination plant built near Regba and Lohamei Hageta’ot, two kibbutzim in the Acre area, north of Haifa. They worry about having an industrial-type plant near their agricultural fields and homes.
Citizens are concerned that the landscape would change and the plant would create a lot of noise and pollution. They fear the area would then be used to build even more industrial plants. An experts’ report they prepared recommended instead that the plant be built in the Haifa Bay area, which is already industrialized.
“The northern region is really in need of another water source,” said Gil. “We have been delaying the establishment of a plant in Galilee for years due to the opposition of residents, and now we are looking for alternative sites.”
Gil said of the Haifa option: “We need a plant that can pump water from a clean part of the sea and not in an area such as that bay, where there are still problems with pollution. What is clear is that wherever the new plant is built, it will take at least five years to complete it. And that will leave residents of the north still dependent upon the number of rain clouds hovering over Israel.”
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