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A New Paradigm: Ecological Sanitation

- Project overview by Huguette Allen

Centralized sewering and wastewater treatment sanitation systems were designed to solve severe environmental and health problems caused by open sewers and cesspools.

Today centralized sewage and wastewater treatment systems are proving to compound environmental problems and to be unsustainable and costly.

They require energy, resources and capital intensive technologies. Their end product is toxic, disease and pollution-producing, and has no redeeming qualities. In addition to high costs, this presents a twofold problem:

  • Loss of valuable nutrients, (see links between hunger and sanitation, page 4)
  • Pollution of domestic and international waters

Flush toilets use potable water which comes with a high treatment cost and account for 40% of the residential demand for water. They represent the largest single category of domestic water use and the only one with significant room for reduction. 

Communities around the world that wish to save water, improve water quality, save money, and contribute to food security are shifting to Ecological Sanitation. This new paradigm is based on three principles:

  • preventing pollution rather than attempting to control it 
  • sanitizing the urine and the faeces
  • using the safe products for agricultural purposes

Types of Ecological Sanitation:

There are two major types of ecological sanitation. Both reduce water usage. The first consists of composting toilets that use little or no water and produce compost. The second consists of Living Machine®s and constructed wetlands and produce only water as output since the solids are taken up by various aquatic species and plants. One can see the applicability of both systems in different situations, such as shifting from flush to composting toilets, and using Living Machine®s or such, to treat grey water and stormwater. 

Various types of toilets can produce a compost that is safely returned to the soil thus closing nutrient loops (nitrogen, phosphorous, potassium). This is being used increasingly around the world including the China-Sweden Erdos Eco-Town Project, Dongsheng, and Hillerod, Denmark (urban area pop.: 29,382; municipal pop.: 46,354) and is highly recommended by five independent research institutes: as a way to ensure food security. 

Living Machine®s consist of tanks teeming with live plants, trees, grasses and algae, koi and goldfish, tiny freshwater shrimp, snails, and a diversity of microorganisms and bacteria. Each tank is a different mini-ecosystem designed to eat or break down waste. They are used by businesses, schools, and government agencies in climates as diverse as the maritime Pacific Northwest, the arid Mojave Desert, and temperate (seasonally very cold) New England.

See examples of Ecological Sanitation systems in the attached document entitled "NewParadigm".

This document was written as a response to a request from Ehren Lee of Urban System, sent to me on September 28th. Since I had been advocating a different way to deal with “wastes”, Ehren suggested I do some research that would include case studies of the use of waterless toilets in the Pacific Northwest.

As I worked, I decided to expand the research to include ways to treat stormwater and to recycle grey water.

Please realize this draft is not meant as an exhaustive study of Ecological Sanitation but as a prompt to our committee to take the opportunity before us to look at how we can shift from costly collection and treatment systems, to more economical, environmental and healthier management systems.

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