ted 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.
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 Instit