120 The City's Challenge in Resource Use 



ation. It is the concentration of a large number of humans and their 

 activities that creates the pollution problems, once again under the 

 take-off principle. Rivers, lakes and oceans, land and free-flowing air 

 can take, diffuse, and oxidize a mechanically and chemically specified 

 quantity of defined additions v^ithout destroying the general balance 

 of nature involved or making the water or air offensive or poisonous 

 to man. You have to go only shghtly beyond this point of tolerance 

 to have the whole thing go bad. While there are some notable cul- 

 prits in remote locations, especially certain mines, mills, and chemi- 

 cal plants, it is the activities within the cities that are now the great 

 offenders. They place a great strain on the natural resources of clean 

 water and pure air. 



Not only are water and air polluted, but at times the land itself. 

 In the suburban rings we now have tens of thousands of acres of 

 septic tanks, many of which are already beyond the carrying capacity 

 of the land. Just a little more density, a few more subdivisions, and 

 millions of suburbanites will find that their sewage is in their cellars.^ 



Increasingly, also, the disposal of other wastes from urban con- 

 centrations will become more demanding. Already many cities are 

 finding it difficult to dispose of solid wastes within their own bound- 

 aries, such as ashes, tins, and other noncombustible rubbish. They 

 fill all the swamps in sight, and reach farther and farther into their 

 neighboring countrysides to find dumps. Radioactive wastes will now 

 intensify this problem. And while the junkman is a wonderful con- 

 servationist, we have made precious little real progress in reclaiming 

 our increasing mountains of urban waste. 



The cities of antiquity encountered no difficulty in rising above 

 their own rubbish and rubble.^ But we moderns have invested so 

 much in subsurface works and have such excellent excavating machin- 

 ery, such firmly set street grades, and have so much putrescent gar- 

 bage, tin cans, and other junk, that we are driven to burn and cart 

 our wastes away, instead of raising the general level of the urban 

 land from century to century. We too "make land," but usually out- 



* "How Good is Our Land Development?" Urban Land, April 1956. 

 ^This is true even of London. See William T. Hill, Buried London (London: 

 Phoenix House, 1955). 



