32 WATER SUPPLY FOR DOMESTIC USE. 



between the three wells. In 1885 a shaft had been commenced 

 near a corner of the waterworks yard, but had to be abandoned 

 on account of a large body of suspicious water met with coming 

 from a fissure in the chalk. On March 13, 1893, a new heading 

 was commenced, which proved to be just beneath this fissure, 

 and on April 14, a large fissure was struck. The water derived 

 from this new heading was, to a certain extent, allowed to mix 

 with the general water supply, and cases of typhoid fever broke 

 out in nine or ten days after, and within a fortnight or three 

 weeks the main outbreak occurred. 



The question arose as to how the water could have become 

 contaminated ? Dr. Thompson, in his Report to the Local 

 Government Board, says : " With a view of testing whether 

 the abandoned shaft of 1885 had led to the discovery of a fissure 

 which communicated with the new heading below, he caused a 

 ton of salt in solution to be thrown down the fissure, and had as 

 a result, an increase of chlorine in the adjacent well of from 5'0 

 to 35-8 parts per 100,000 within an hour and a-half from the 

 commencement of the experiment. It became thus evident that 

 any sewage contamination of the surface of the ground above the 

 fissure experimented on would permit of the entry of dangerous 

 material to the public water service. Local contamination was 

 abundantly shown by the existence of old disused drains leading^ 

 to sewage pollution of the soil overlying the chalk in which the 

 wells, &c., are sunk. Dr. Klein was able to demonstrate the 

 existence of the typhoid bacillus in the water of the contamJ- 

 nated wells. 



Wells, such as I have described, may be termed surface or 

 shallow wells, in contradistinction to Artesian W^ells, so named 

 from the province of Artois, where they have been long in use. 

 The term artesian is confined to wells, the water of which rises 

 above the surface ; and wells sunk into geological formations and 

 deep beds are called deep wells. The water of artesian and 

 deep wells is less liable to contamination than that of shallow 

 wells. This can be easily understood when we consider the 

 conditions under which the water is stored in the reservoirs 

 which yield the artesian and deep well supplies. In the case of 

 Queensland, for example, the sources of artesian water supply 

 are supposed to have their origin in that portion of the rainfall 



