The Health Ministry has just completed its first-ever survey of Israelis' water-drinking habits to help experts determine where to add calcium and magnesium to desalinated water from which vital minerals have been removed. Recent studies have shown a connection between the drinking of "soft water" lacking minerals and an increase in coronary heart disease. The ministry said on Monday that it was constantly working to ensure that there were enough minerals in the water that were beneficial to good health. The survey, conducted partly in summer and partly in winter among a representative sample totaling 1,600 people, was a cooperative effort by the ministry's nutrition department and the Hebrew University of Jerusalem. The survey looked at not only how many glasses of tap water and other types of water and beverages average Israelis drink in summer and winter, but also whether they eat foods rich in these minerals, where they live, and their socioeconomic level. The ministry found that Israelis drink an average of 2.9 glasses of tap water a day, plus 14 glasses of other beverages including soft drinks and juice. Unsurprisingly, people in the South drink 15.3 glasses a day compared to 12.8 in the North. Residents of Kibbutz Ma'agan Michael - between the southern Carmel mountain and the Mediterranean Sea at the foothills of Zichron Ya'acov - drink more tap water per capita (five glasses on average per day) than anywhere else in the country. In addition, the survey found, the use of filtration devices is more common in areas that receive water from the National Water Carrier. Women drink less tap water and other beverages than men. Consumption of bottled water was highest in the South. Consumption of sweet bottled beverages was twice as high in the summer than in the winter, and much higher in the South than the North. The average Israeli drinks two to 2.5 cups of coffee, half to one cup of tea, and half a cup of soup per day, the ministry said.