26 March 2013

Sanitary City

A sanitary city is an urban form developed to correct the ills and hazards of the industrial city (Fig. 1). 

Figure 1. Industrial city hazards stimulated the development of the sanitary city.

Sanitary cities segregate wastes and other hazards from residents.  Early sanitary cities accomplished this by collecting and piping sewage downstream (Fig. 2) or out to sea, by landfilling solid waste, by erecting tall smokestacks, and by employing single-use zoning.  As environmental awareness increased, the waste streams were treated more effectively.  Sanitary city solutions are engineered, management is based on separate sectors, such as water, traffic, health, etc., government is the active decision making and funding entity.  Furthermore, some aspects of environmental improvement assume that the demographic transition will play a role in improving people’s well being in the sanitary city.

Figure 2. The sanitary city depends on massive investment in infrastructure, originally designed to remove or segregate hazards from residents.  Here a large storm drain emerges from below ground to join a surface stream.

Sanitary cities are now common in countries where industrial or colonial wealth accumulated.  Baltimore is an example of a sanitary city, characterized by separate sanitary sewer and stormwater runoff collection systems.  Sanitary sewage is treated at least to the secondary level, in which biological digestion occurs at the end of the collection pipe.  Solid waste is collected, and an incinerator reduces the volume while generating electricity.  Recycling is a relatively recent addition to the sanitation regime.  In the United States, the Clean Water Act and the Clean Air Act have been important in reducing the impact of urban areas as pollution generators.

Why Important: 
The sanitary city has been an immense boon to human health and wellbeing in those nations and regions that have been able to implement and maintain the expensive technical infrastructure.  However, many cities or informal settlements have little access to basic sanitation, such as clean water delivery and collection and treatment of human and animal waste (Fig. 3).  In sanitary cities there is an increasing recognition that there are still improvements still to be made in environmental quality, and reduction of resource use, including energy, water, and building materials.  The increasing concern with environmental equity and quality of life and livelihood have been added to the mix by citizens and urban policy makers, who now call for cities to become more sustainable.  Hence, the sanitary city as a current state and ideal is contrasted with visions of the Sustainable City.

Figure 3. Informal development near Cape Town, South Africa.  Such shanty and favela settlements are common in rapidly growing cities around the world.  Many originally had no or rudimentary sanitary infrastructure, and such conditions persists in many.  Photo S.T.A. Pickett.

For more information:
·         Gandy, M. 2003. Concrete and clay: reworking nature in New York City. MIT Press, Cambridge.
·         Melosi, M.V. 2000. The sanitary city: urban infrastructure in America from Colonial times to the present. Johns Hopkins University Press, Baltimore.
·         Olson, S.H. 1997. Baltimore: the building of an American city. The Johns Hopkins University Press, Baltimore.