Not so simple samples

The goal of this project is to reduce the need for frequent and costly emptying of pit latrines. The benefit worm-based sanitation brings is that it lowers the volume of faecal waste through the worm digestion, is odourless, and fly-free. The Tiger Worm Toilet (TWT) thus offers us a more sustainable sanitation solution over the longer term – both economically and environmentally.

Oxfam’s TWTs have been running in Sittwe for 20 months, alongside control pit latrines. We’re following a monitoring protocol – routinely collecting and analysing data on the presence of faecal matter and vermicompost (worm poo) in the toilet pits, and gathering user experiences.

The question to answer next is – how safe is the vermicompost for disposal or reuse in some way? To answer this, we needed to collect samples of the vermicompost in the TWTs pits and the sewage-like contents of the control (pour flush) pit latrines for technical evaluation. We use a control to compare the results of our innovation to the current technology that is being used.

Finding laboratories with the ability to undertake the sample tests we needed proved a challenge! Dr Claire Furlong assisted the Sittwe and Yangon teams with this mission.

What to analyse & why

We chose to have our samples analysed for the following:

• Total solids and volatile solids – this tell us how wet the materials are and gives an estimation of whether the samples can be further broken down.
• Indicator bacteria – this tell us if the materials contain pathogenic bacteria, and how safe it is to handle and dispose of.
• Human helminth (parasitic worm) eggs – this will tell us if these eggs are accumulating in the Tiger Worm Toilets.

In contrast to all previous studies on Tiger Toilets that concentrated on the liquid (effluent) that infiltrates into the soil, we decided to focus on the material inside these systems – because this tells us how safe it is to handle and dispose of.

We also decided to look at human helminth eggs, as we know that parasitic worm infections are rife in this part of the world. Helminth eggs are very resistant and can survive for up to seven years. As the Tiger Toilet has a filter that traps the solids, we can also check to see if we’re accumulating these eggs in the vermicompost compared to the control latrines. If this were to happen, we would need to give guidance on how the vermicompost should be safely disposed of.

Location

As we don’t have a laboratory ourselves, we needed to identify one to analyse our samples. It truly has been a team effort with the logistics and WASH teams networking to find the right laboratories with the correct testing protocols and capabilities. In Yangon, we could get the bacterial analysis done at the ISO Tech Laboratory (Waterworks Engineering Group).

For helminth and solids analysis, we contacted our neighbours in Thailand at the Asian Institute of Technology (AIT), and the world leaders at analysing these type of samples – the Pollution Control Group at the University of KwaZulu Natal, Durban, South Africa. They developed the method for helminth analysis for such samples. Through a multi-country approach, we were able to achieve the full sample analysis we’d hoped for.

Collecting samples in the rainy season

With expert support from Lucy Polson and Claire Furlong, the team in Say Tha Mar Gyi Camp were responsible for collecting and packaging the samples during July and August, for transport to the three laboratories. Sampling equipment was made using materials bought from the local market. A long-handled mattock (hoe) was used to scoop out vermicompost samples, and a plastic cup attached to a mop handle was used to collect the more liquid control latrine samples.

Transportation logistics

Several transportation options were explored, which provided further challenges. The bacterial samples (destined for Yangon) were kept chilled, collected by a logistics company in Sittwe, flown to Yangon and delivered by Oxfam to the laboratories – all within 24 hours. The samples for Bangkok were hand delivered to the laboratory, while samples for Durban were couriered and arrived seven days later.

Overall, the challenges were overcome thanks to the dedication of the project team and their enthusiasm for such comprehensive research. Bringing together the logistics, management and technical WASH teams has resulted in an indomitable ‘Tiger Team’!

Results

Full sample results to follow…stay tuned! We’re hugely excited about this – not only because it’s the first-time Oxfam has undertaken such a level of TWT analysis, but also this is one of the first studies to ever test the vermicompost from these systems. It will provide us with meaningful and robust data that will inform Oxfam, and the sector, in finding sustainable sanitation solutions for emergencies.