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Emergency Sanitation at the 35th WEDC conference

July 22, 2011

Emergency sanitation was present at the 35th WEDC conference (http://wedc.lboro.ac.uk/).

All presentations and doccuments will be soon available on the net, but we publish below the presentation about the portaloos used by ACF in Haïti.

The emergency operations that followed the earthquake in Port-au-Prince showed the humanitarian community the importance of ready-to-use solutions for both water treatment and sanitation. In most situations, fortunately, the excreta management problem would be solved by digging pits and/or burying the waste. In such a context, emergency squatting slabs are a good solution. In areas where digging is not possible, portable toilets such as the ones used in Haiti could be an alternative.  The portable solution, however, is feasible and cost effective only if the cubicles can be rented locally. It would not make economical sense and it would be a logistical nightmare to store the cubicles and desludging equipments in a contingency stock, and to send them (by plane?) in the affected area. Another necessity is to be able to access a safe final disposal site for the sludge. Without such a facility, we would just move the problem somewhere else…

Pa fouillé la: the impossibility of digging
Reasons for not being able to dig pit or trench latrines were numerous after the earthquake. Most of them were linked with the fact that the disaster took place in a town, a capital city: streets were paved, narrow, oppen spaces were used by refugees or the owner did not give the authorisation to dig.

The "portaloo", the hand washing station and the cubicle attendent (photo J. Eyrard)

 

The portable solution
The latrine is a self standing plastic box equipped with a door, a lock and ventilation. The toilet seat is located over a 200 litres tank. This tank is collecting the urine and faeces, with no addition of water nor chemicals (optional, not recommended if service is daily). These toilets can serve up to 50 persons per day. With so many users they need to be cleaned everyday (or preferably every night). This service is done by a vacuum tanker operated by the same company. The option to rent only the toilets and to do the service with NGO tankers was considered but found not relevant: To manage a fleet of at least 5 trucks is a difficult task as these are difficult to maintain equipments: the pumps are the critical part. It is therefore recommended to rent the full service from the same company.

The portable toilets need to be supervised by a cubicle attendant to guarantee maintenance and cleaning. Each row of 10 cubicles was under the responsibility of one attendant, in charge of distributing the toilet paper and keeping the hand washing device full of water and soap. The attendant was a community member, paid for this job for a period of 15 days. Every 15 days, the attendants were changed to allow turn over among the community so that a maximum of people could benefit from the project. This idea was found to be relevant and added a great value to the project, by keeping the hand washing facilities operational (with water and soap) and “humanizing” the latrines. It also contributed to ease user’s mind about using the latrines – there was always a security issue in Port-au-Prince after the earthquake for women and young girls going to the toilets. Hand washing stations with soap were also installed, as they were not included in the rented cubicle – it was possible to rent an optional hand washing station, but this option was not feasible in the Champ de Mars because this hand washing station needs a connection to water network to function. An autonomous hand washing station with a container would be a better option in such context: a design point that should be improved.

A good solution for emergencies?
The portable toilet is a ready-to-use solution that can be deployed quickly in any emergency. From the users point of view the portable latrines is a good solution: it is users friendly, and provide a high class standard in terms of comfort and safety. There is no risk of falling into the pit or the tank, and the door is equipped with a lock. A larger cubicle is also available for wheel chair access, which is also a necessity in emergencies.

The main inconvenient is the price due to the necessity of a daily service. The price is depending on the number of toilets rented and the duration of the contract. This solution would therefore fit better for large numbers of units and long term contract. The cost efficiency must be balanced with other option (if other options are available) and should take into consideration quality of the service and rapidity of the installation, two elements that can make the difference.

To be implemented within the first days of an emergency, the latrines need to be stored in a significant amount in a country where a toilet rental company is operating. This is not really possible due to the logistical constraint and the financial risk and to rent the latrines to “normal” customers would jeopardize the availability of toilets in the case of a sudden emergency. It would not be recommended to store portable latrines somewhere in the world to be dispatched for the next emergency, considering the volume of storage and number of cubicles. It would be cheaper and faster to have a pre-signed agreement with the rental companies, with clear terms and condition for production and shipping of large quantities of latrines (and desludging equipment) in various “hot spots” where they could potentially be needed: flood prone areas, urban centres, etc. This would also allow humanitarian community to have negotiated prices with the rental company. A price around 10 USD / day / user is competitive with other semi permanent solutions, but can be met only if renting larges quantities of latrine or if a clear agreement is established in advance.

Desludging
To empty the portable toilets there are two solutions: a vacuum tanker or a desludging pump (self priming diaphragm pump). The first one is acting as a giant vacuum cleaner and can suck up the waste from the tank as well as faeces “accidentally” dropped around the seat. The second one needs to be operated with a tank of fresh water. The operation consist in injecting fresh water in the tank to dissolve the content, and then to pump it. The first system is more tolerant to small objects and stones that may have been drop in the toilets. It needs a specific tanker, which is not always available in country. The second option can be “home made” with a platform truck, a diaphragm pump and two tanks, one for the fresh water and one for the sludge. It is more difficult to operate and less resistant to objects drop in the toilet. For large size projects, the rental company would provide proper vacuum tankers. This is obviously the best option.

Final disposal of the sludge
This is a critical issue. Under normal circumstances the final destination of the sludge should be either a sewer discharge station (SDS) connected to a semi centralized treatment facility (constructed wetlands), or a sedimentation pond / drying bed, to allow proper treatment of the sludge before final disposal safe for environment. Such facilities are not available everywhere: before even thinking about renting portable toilets, one should think about the final destination of the sludge. Once the toilets are installed and used, the service is daily and if there is no dumping site ready before the installation of the latrines consequences can be huge for the environment. The minimum facility, to reduce the environmental risk, would be an isolated field, far enough from houses and water sources, where a large pit is dug to collect the waste.

The Truitier landfill near Cité Soleil. Not exactly the perfect dumping site but there is no other solution so far in Haiti (photo J. Eyrard)

Conclusion
The main constraint faced in Haiti was the quantity of sludge to move: 5 full trucks every day. This was due to the fact that the tanks were collecting faeces and urines. Knowing that an adult produce daily 1.5 litres of urines and 0.5 litres of faeces, Urine Diversion Dry Toilets (UDDT) could be an option to reduce the amount of waste to transport every day if urine can be infiltrated in the soil near the latrine (which is not possible everywhere) or used for farming. Such UDDT are not yet operational for emergencies, but the technology is promising. The best option would to have it compatible with the existing emergency squatting slabs, the KK Nag Magic, for a faster and safer deployment during emergency, in contexts where digging is not possible. Portable latrines are another option, to consider if rental companies can commit themselves to significant amount of cubicles and if safe waste final disposal facilities exist in the country.

Complete paper will be available soon on the WEDC web site.

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