What we do

• The need
• How we work
• Where we work
• Policy and research
• Statistics
• Sustainable technologies
• Technology notes
• Sustainable technology in action
• Toilet technologies
• Water source options
• Technical FAQs
• SoPHE Young Engineers Award 2011
• Technologies
• Documents and publications
• Impact of our work

Forward to a friendPrint this page

Send this page

Email address:

Separate mutiple addresses with a comma (,)

Your name:

Your email address:

Please enter the answer to the sum below. E.g. For "What is Ten plus Three?" enter "13". Doing so helps prevent automated spam.

What is Fifty plus Two? *

 

The details you provide on this page will not be used to send unsolicited e-mail, and will not be sold to a third party.

Thank you for telling a friend about WaterAid

We're sorry, an error occured while trying to send this page.

SoPHE (Society of Public Health Engineers)Young Engineers Award 2011

1. The Challenge

Design a low cost dewatering device for a decentralised waste water treatment system.

2. Background

A number of WaterAid's Urban programmes have begun to work with municipalities and/or utilities to develop simple low-cost systems for a complete Faecal Management Cycle. Essentially, where sewers are not an option in the near future and where existing sanitation facilities consist of low-cost latrines (dry, pour flush or even ecological), there is a need for the collection, transport, treatment and disposal of this waste. At present, much of this waste is simply left buried or dumped locally, exacerbating local health problems.

The management model that WaterAid is working with is based on a simple solid waste management model that includes primary and secondary collection phases, with the primary collection part being wholly managed by community groups or small scale contractors. However, unlike solid waste, an extremely large proportion of the waste is water. The current model simply involves the primary collection teams emptying the pit toilets or septic tanks using a VacuTug or a manual pump called a Gulper.

The contents of the pits are then transported large distances to the nearest sewerage treatment plant. Apart from being costly, extremely heavy, voluminous and slow to transport, the waste is also extremely toxic, carrying a high BOD (biochemical oxygen demand). Ironically, despite the water content, the waste is also too solid for the traditional treatment plant, often causing major system failures.

WaterAid has recently been considering using Decentralised Waste Water Treatment Systems (DEWATS – 'glorified' septic tanks) as part of the solution. The idea is that the waste is first collected and treated locally as an interim step, before being transported. Although this is technologically achievable and fairly cheap to operate, the final waste still has a high percentage of water.

3. The Brief

WaterAid is looking for a very cost effective, robust and simple way to dewater this waste. Clearly the waste water will need to be safely disposed of locally.

WaterAid sees the challenge as two fold: Developing a design for a DEWATS that includes a DEWATERING stage. The system should be able to produce easily transportable solid waste cakes to be taken elsewhere for further composting as well as safely disposing of the liquids on-site.

Note that the subsequent composting phase could form part of a potential business incentive. Competition entrants should consider all possible ways to reduce the costs that may be passed on to poor households. This could be through simplifying the technology or considering the entire management cycle and looking for ways in which small scale businesses or community groups are able to extract economic benefit from the phases.

4. Entry

Teams of up to 3 people, aged 18-35 on 30 September 2011.

The entry submitted by competitors or teams of competitors must be made of:

• A concept design for your proposal on a one A1 poster with a maximum of 1500 words and should include at least
  two diagrams / sketches.
• The submission should include the name(s) of the participants their date of birth and contact details.
• Six copies should be provided.
• Additionally the competitors may also supply a CD with a pdf version of their submission.

• Low running costs
• Minimal technical complexity
• Small footprint
• Robust
• Ability to manufacture locally with local materials.

6.2. Judging Process 

The first phase will be for the judges to short list entries on the material submitted. Short listed teams or individuals will be invited to present their idea to the panel. They will be given the opportunity to make a short presentation (up to 20 minutes) followed by a 20 minute question and answer session.

For more information, please go to the CIBSE website.

Top