Less than half a percent of drinking water supplied by the Mekorot water company exceeded allowable pollution limits in 2010, according to a report released on Tuesday. That is a dramatic improvement over the 1991 level when 6.5 percent of the samples in Israel exceeded allowable limits -- and also well below the five percent limit recommended by the World Health Organization.

The report, which was published by Mekorot to mark its 75th anniversary, states that the company checked approximately 27,000 samples for disease-causing bacteria and parasites. Only 0.07 percent of the samples were found to contain such contaminants.

The study examined the quality of the water Mekorot supplies through a national system, which includes the Kinneret, the National Water Carrier, wells, and main pipelines to cities.

Mekorot supplies about half of Israel's water. The other half is provided by water corporations established by municipalities or jointly by communities.

Mekorot also checked some 70,000 samples for chemical pollution, such as the remnants of pesticides and fertilizers. Such contamination was found in 23 samples, which is 0.03 percent of all the tests.

Over the past four years, Mekorot has been using chemical and biological systems to disinfect water in the reservoir to which the Kinneret water is channeled before it is distributed via National Water Carrier pipelines. It also operates a facility to filter water to reduce turbidity.

The main challenge to Mekorot and the water corporations is currently the increasing salination of ground water due to over-pumping. According to the lastest report of the Hydrological Service, issued in 2009, only 39 percent of the coastal aquifer was still of good quality and 11 percent has become unusable. The rest is defined as "satisfactory" in terms of quality.

Four years ago, Mekorot supplied 276 million cubic meters of water from the Kinneret and only 153 million cubic meters of desalinated sea water. Two years ago, that figure was nearly reversed with 277 million cubic meters of desalinated sea water and only 176 million cubit meters from the Kinneret.

Water quality will improve further after the Knesset passes new water regulations shortly, according to Prof. Avner Adin, who headed the Health Ministry committee that set the new standards. "Among other things, the level of bacteria will have to decline to zero and all aboveground water will have to be filtered," Adin said.

According to Storenext, a firm that gathers statistics on retail food purchases, in 2010 Israelis purchased NIS 420 million worth of bottled water, and in 2011 - NIS 397 million, a decline of 5.5 percent.

A major factor in the decline is the entry into the market in March 2011 of Electra's home filtered water dispenser. Electra's product turned out to be powerful competition for Strauss' Tami 4 filtered water dispenser, and prices of both products fell.

Over the last few years, the Environmental Protection Ministry has strongly endorsed drinking tap water. Minister Gilad Erdan recently announced a campaign to encourage people to drink tap water. From a health perspective tap water is fine, Erdan said, and bottled water is a burden on the environment because it uses natural springs and the plastic bottle it comes in is a source of litter and pollution.

People's desire to save on bottled water can also be seen in their preference, according to Storenext, for water brands that are less expensive brands than the market leaders, Mei Eden and Neviot.