The chairman gave the direction after a number of members pointed out that tap water or polluted water was being sold as mineral water. They were dissatisfied with Health and Family Welfare Minister Dalit Ezhilmalai's reply to their query on steps being taken up to remedy the situation.

The chairman said water was a basic necessity and the government ``should come to the House prepared'' when the question was raised next.

Replying to a query by K R Malkani on the specifications for mineral water formulated by the Bureau of Indian Standards (BIS), Ezhilmalai said the food health authorities of states and Union territories keep a vigil on the quality of mineral water by drawing random samples of mineral water from the market and checking their quality.

This however did not satisfy Malkani who wanted to know the numberof samples found substandard and whether the government had any plans to make BIS certification mandatory for manufacturers of mineral water.

Ezhilmalai said water did not come under his ministry alone. It was connected with other ministries and municipal corporations, and therefore it could be deemed a Health Ministry issue.

The chairman asked Minister of State for Parliamentary Affair Ram Naik to arrange an inter-ministerial meeting to discuss the matter.

Several cases of so-called mineral water turning out to be ordinary tap water were detected in various parts of the country, the members said. They demanded that there should be a proper certification by some government agency assuring that the water sold in the bottles was safe and also whether it was mineral water or not.