Aloha again,

Since we are considering high density urban poor settlements we’d like to include a central composting station for the UDDT (previously named Ecosan but thanks to Chris Canaday we’ve changed that).
Does anyone have construction specifications for a composting centre in Sub Saharan Africa? We’re assuming that it’ll be a paved ground and manual turning of compost as easiest form.

Many thanks in advance and
Cheers,
Lars Pelzer (saniman)

Dear Saniman,

Congratulations on undertaking such important work.

Do I understand correctly that you will be estimating Greenhouse Gas Emissions via published data and theoretical calculations? Given the complexity of the processes involved, it would be excellent for someone to measure these emissions empirically.

A few comments on your attached table:

1) EcoSan is a broad category of techniques to recycle nutrients and not treat excrement as waste. I believe you refer to the UDDT (Urine-diverting Dry Toilet).

2) Within the UDDT category, it would useful to analyze different cover materials, including sawdust and wood ash (which are commonly used), but also more biologically active substances, such as rich, organic soil (including compost from kitchen waste or recycled UDDT cover material after storage and/or treatment). Please take into account the potential for soil microbes to consume these gases before they are emitted into the air.

3) What would be the emissions from WC + Sub-surface-flow Constructed Wetland?

4) Please give us a link to a description of the CleanTeam Technique and the chemicals used. www.cleanteamtoilets.com/our-model/ does not give any useful detail.

5) Please include in your calculations the GHGs emitted during the production and operation of the vehicles used to transport materials.

Good luck with your work. I look forward to seeing the results.

Best wishes,
Chris Canaday

As Cranfield University’s students we are currently working on a DFID induced and WSUP sponsored project on estimating the greenhouse gas emissions (GHGE) from different options of the total sanitation value chain for urban poor settlements and comparing these. Starting with open defecation as its simplest form and improving sanitation step by step leading to Water Closet as most common option in urban areas of developed countries (see attached Table 1).

In the following two weeks we will post questions that occurred during the project and hope for input from experienced professionals in order to tackle this complex topic, starting with the first one today:


In order to calculate the GHGE emissions from option 7 and 8 in attached Table 1 we need a COD value for the effluent of a pour-flush squatting pan. We thought about taking the value of a pit latrine but since the excreta are diluted with water from flushing we are not sure and we unfortunately couldn’t find anything in recent literature. Can anyone provide values for that?

Many thanks in advance!