Ancient Roman latrines / latrinae, Ostia Antica

Human waste – everybody poops.


  • toilets
  • human waste
  • safe drinking water
  • water for cooking, bathing
  • disposal of waste water
  • run-off, storm drain

Sanitation systems, mid-19th century – A major reason we live 40 years longer than we did in 1880

Water and Engineering – Many of the great engineering achievements beginning at the earliest times through the present have been associated with providing a reliable water supply and with disposing of wastewater. The Romans built aqueducts that supplied Rome and other cities with drinking water between 300 {BC} and {AD} 300. The sewer system in London was developed during the late 1800s.

Most people in the developed world have access to safe drinking water. Water quality standards have been established for drinking water. Engineers developed techniques to provide potable water and to treat wastewater so that it does not unduly pollute the environment.

Potable water


November 19th was World Toilet Day and, though it sounds funny, it was designed to bring attention to the lack of public sanitation in many parts of the world.

Worldwide, 2.6 billion people do not have access to adequate sanitation and the resulting diseases and water pollution cause 1.7 million deaths and a loss of $84 billion in worker productivity each year. In Kenya’s slums, a staggering 8 million people lack access to adequate sanitation.

  • sustainable sanitation cycle – build, and franchise a dense network of low-cost sanitation centers, eventually expanding to every block of the slum. Each center will provide basic high-value services: hot showers and clean toilets. The sanitation centers deposits the waste in air-tight containers. Each day, the full containers of waste from the operators are brought to Sanergy’s central processing facility that converts human waste into biogas through industrial-scale anaerobic digestion process. The output from the biogas generation will be processed into high-quality organic fertilizer, which will be sold to commercial farms and small hold farmers.
  • toilets in Roman cities
  • flush toilets
  • chemical toilets

What do you think?
Converting human waste into rocket fuel – An anaerobic digester process, was developed in which microorganisms break down the organic material and kill pathogens in the absence of oxygen to produce a mixture of methane and carbon dioxide.

  • Ask – What to do with human waste when we start spending long periods of time on the Moon? Carrying back stored waste from such long-term missions would be impractical, and dumping the waste on the Moon’s surface has been ruled out as an option. NASA needed to come up with some alternative ideas.
  • Imagine – What can be used to turn human waste into something useful? There is a lot of energy in waste and it would be good to be able to use that energy. Human waste is organic. So long as there aren’t any disease causing germs in it, it could be turned into fuel such as methane and carbon dioxide
  • Design, Build – The bioengineering researchers came up with a digester to do just that – produce a mixture of methane and carbon dioxide. The methane could be used as rocket fuel.
  • Improve – The digestion process would also produce non-potable water, which could then be split into hydrogen and oxygen through electrolysis.

That’s engineering

  • anaerobic
  • electrolysis

Engineering ideas

  • bioengineering, methane, energy, organic, non-potable

Do it
Here are some challenges for you to work on…

  • Find some interesting ways people are trying to “recycle” human waste – pee and poop

Learn more…