Sources of Drinking Water
According to the latest statistics, 4,700,000 inhabitants out of a total population of 7,700,000, or 61 per cent, derive their drinking water from a water system. Of these 444 communes, 142 secure their water from dunes, 25 from subterranean water drawn from dunes, and 49 from river water. Some communes, such as Amsterdam and Groningen, utilize partly river water and partly subterranean water. In 1929 there were 149 water systems, 109 of which are exploited by public administrations and 39 by private companies. From a report recently published on this important question by Messieurs Liefrinck and Krul, certain points of general interest have been taken. The public health law of June 21, 1901, placed all questions concerning the hygiene of water, soil and air under the control of inspectors of public hygiene and created at Utrecht a central laboratory of public hygiene charged with annual chemical