PROTECT I OX OF RIVER AXD HARBOR WATERS ]~ 



tribution of sewage over a large surface of ordinary agricultural land, having 

 in view a maximum growth of vegetation consistent with due purification ." 

 Progress in England along these lines was rapid, so that over two hundred 

 irrigation areas of various sizes were in operation by 1883. Many are -till 

 in use to-day and on the continent, Paris and Berlin offer classic examples 

 of this method of disposal. The Paris sewage is distributed on private 

 land and it is not easy to form a sound judgment as to the success of the 

 system. The Berlin farms on the other hand are operated by the city and 

 offer an excellent example of sewage farming at its maximum of efficiency. 

 The farms include 39.000 acres of excellent sandy soil, an area of over >ixty 

 square miles. Grass and cereals, potatoes and beet> are cultivated and 



Intermittent sand filter bed. Photograph of a model in the American Museum 



dairies and distilleries are maintained for the utilization of the crops. Even 

 the effluent drains are stocked with fish. The farms are operated by convict 

 labor, and with German intelligence and German military discipline, the 

 enterprise is not only successful as an experiment in sewage disposal but 

 is also economically profitable, for the crops cover all costs of operation and 

 pay for a part of the interest charges on the land. 



In general, however, the results of broad irrigation have been by no 

 means so favorable. The process requires large areas of land. The sewage 

 of a community of one hundred persons would need from one to two acres; 

 and the soil must be loose and sandy in character. Where, as in many 

 English towns, the attempt is made to treat sewage on clayey soil, disaster 



