8 SEWAGE AND ITS PURIFICATION 



for the conveyance, storage, or distribution of a water-supply, 

 or flowing directly or ultimately into such water-supply," within 

 which distance the following are specially prohibited to be 

 located, deposited, or discharged : Cesspools, privies, any 

 urinal or water-closet not discharging into a sewer ; any human 

 excreta or compost containing them ; house-slops, sink-waste, 

 or other polluted water ; any stable, pig-sty, hen-house, barn- 

 yard, hog-yard, hitching or standing place for horses, cattle, or 

 other animals. The last section would tend to prevent the 

 common and dangerous practice of watering cattle in a stream 

 which is afterwards used as a human water-supply. Other 

 regulations relate to land-manuring,, cemeteries, manufacturing 

 waste, sewers, hospitals for infectious diseases, factories for 

 working skins or hair, slaughter-houses, bathing, and cutting 

 ice, in their connection with water-supplies. 



The " model by-laws " of the Local Government Board 

 prescribe that — 



1. The privy must be at least 6 feet away from any dwelling. 

 This distance seems much too short, but is, unfortunately, 



limited by the amount of ground at disposal and the con- 

 venience of the householders. 



2. That it must be 40 or 50 feet away from any well, spring, 

 or stream. 



The distance is not always sufficient to prevent infiltration 

 into sources of water-supply, as, although the passage through 

 40 or 50 feet of porous soil is ordinarily sufficient to remove 

 danger from polluted runnings, recorded cases, such as Maid- 

 stone, Worthing, and many I have found in my own analyses, 

 have proved that, owing to the occurrence of cracks or the 

 formation of channels, specific pollution has been able to 

 traverse a much greater space. So that observance of the 

 regulation would not attain safety without examination and 

 inspection at intervals. 



Cases are on record in which the water in a w^ell at a brewery 

 was polluted and the brewings spoilt by percolation of foul 

 matter "through several yards of chalk," and of chalk itself 

 being blackened by the passage of trade effluents through such 

 fissures.^ 



Professor E. Pfuhl ascertained by direct experiment that 

 certain bacteria could be carried in one hour through 26 feet 



^ See also Davies and Tyndale, *' Sewage Disposal on Chalk Soils," Journal of 

 the Royal Sanitary Institute, 1904, p. 643. 



