Medium-term Emergency Sanitation and Upgrading

Emergency interventions aim to provide basic facilities to contain and separate excreta, and to prevent transmission of faecal-oral diseases and the contamination of water sources (see sanitation in emergencies). The medium- and long-term phase of an emergency response follows the immediate emergency phase and typically lasts from several months to several years in complex emergencies. It covers the time where the situation becomes stabilised and more sustainable interventions can be implemented for longer-term use. Community structures may reassemble and morbidity and mortality rates should start to fall. However, emergency situations do not follow a linear progression: some situations may become more acute after improvements, e.g. when the affected population increases, an epidemic occurs, or the security deteriorates (HARVEY 2007).

While the immediate response focuses on the collection and confinement of the excreta, the medium-term response focuses on the treatment and management of the sludge as well as greywater, solid waste and stormwater. All wastewater treatment systems in emergencies produce sludge – either continuously or intermittently. This sludge requires careful handling and disposal in a pit, an incinerator or on agricultural land. 

Emergency preparedness planning should include identification of suitable sites for the safe disposal of sanitary wastes, such as sewage and faecal wastes from latrines (GLOBAL WASH LEARNING PROJECT 2008). 

Priorities, stakeholder involvement and technology choice for the sanitation actions in an emergency response after the immediate emergency phase. Adapted from JOHANNESSEN & BIKABA 2009

While certain emergency phases can be defined, the choice of the actual sanitation system for each phase depends on the particular situation e.g. if people live scattered or in a camp, if they are in an in-situ or an ex-situ situation (see also sanitation in emergencies), in urban or rural areas, and the specific needs related to sanitation.

Simple pit latrines are by far the most common technology choice adopted in emergency situations. They should be designed as deep as possible (at least 2m) and covered by a slab (e.g. concrete, wood or prefabricated plastic) with a removable lid in order to prevent odour and flies. Ventilated improved pit latrines are designed to minimise odour and flies and do not require water for functioning. Due to their higher costs they are generally exclusively affordable for institutions (e.g. schools and hospitals) during emergencies (HARVEY 2007). When pits are filled, they are usually covered with 1 to 1.5 metres of soil and left for decomposition and a new pit has to be dug out. Diversion of urine prevents excreta collection chambers to fill up too quickly and also limits the risks of groundwater pollution by reducing the infiltration of contaminated liquid into the ground (see also urine diversion toilets and urine diversion components).

Borehole latrines can be constructed very rapidly in a deep soil profile if drilling equipment is available (5 to 10m deep, depending on the groundwater table). But there is a greater risk of groundwater pollution and higher probability of blockages compared to pit latrines. Borehole latrines should be considered only if pit excavation is impossible (HARVEY 2007).

Peepoo bags have been used as a medium-term emergency response, e.g. in Haiti by Oxfam. If collection and safe disposal are provided, this is an efficient way of maintaining hygienic conditions while minimising the risk of environmental pollution.

Ecological toilets (such as urine diversion toilets, composting toilets, terra preta toilets, twin pits pour-flush toilet) also have the advantage of being “dry” and therefore suited for areas with a high risk of groundwater pollution through infiltration of leakage from pits. From a long-term perspective, these solutions also offer the option of using products for gardening and agriculture (see also urine fertilisation or use of compost). However, ecological systems require the user being instructed on how to use them and maintenance is generally slightly higher.

Where users are not used to dry-toilet systems and water is used for the cleansing, pour flush toilets can be implemented. However, they are more expensive than pit latrines and require water. Moreover they have to be connected to collection tanks (e.g. septic tanks; biogas settler or anaerobic baffled reactor), which require frequent desludging as well as transport (see also motorised and human-powered emptying and transport) and further treatment of the sludge.

Package wastewater treatment plants such as Rotating Biological Contactors (RBCs) or activated sludge processes are quick to install, highly automated and provide an effective barrier against pathogens. The disadvantages include the high costs, high energy consumption, and that they are basically not designed to treat the highly concentrated waste arising from emergency settlements as this may inhibit their performance (HARVEY 2007). Also skilled staff is required for maintenance and spare parts are often barely available locally.

If the emergency situation persists or a displaced population is not expected to return to their homes after a couple of months, a longer-term solution has to be found. For long-term solutions, the same criteria apply as for a non-emergency sanitation system (see also sanitation system).

Excreta from dry sanitation systems can be composted and reused (see also reuse of compost). Arborloos and fossa alterna systems allow for direct on-site reuse of the composted excreta. Faeces from urine diversion toilets can be dehydrated before composting and/ or reuse. Urine can be stored and then applied as fertiliser in agriculture (see also storage of urine and urine fertilisation at small-scale).

Sludge from wet systems (e.g. septic tanks) has to be emptied and transported either manually or by trucks or a sewer system (see PPT) has to be installed. Sludge treatments include small scale and large scale composting, anaerobic digestion, drying beds, settling ponds followed by use of compost, small and large scale incineration or disposal in landfills.

Besides excreta collection and treatment, sanitation also includes the management of greywater. There are options for directly reusing greywater relatively easily (see also vertical gardens and greywater towers). If greywater has to be disposed of, a managed infiltration system needs to be constructed (see also leach field, soak pit or evapotranspiration bed).

Moreover, solid waste has to be managed to maintain proper hygiene conditions. Organic solid waste can be composted (see also large scale composting) or used for the production of biogas (see also anaerobic digestion of organic solid waste). Other waste should be incinerated (see also small and large scale incineration) and finally disposed of safely in landfills.

Finally, the management of surface run-off is often forgotten in sanitation; read more in stormwater management.

Following the flooding of the Rio Beni in Bolivia in March 2008, approximately 20,000 people moved to higher grounds where open defecation presented a health risk. Sanitation units were installed as quickly as possible. Urine diversion toilets were installed and faeces were collected in 200 litre drums and urine was drained into containers for disposal. The faeces were collected each day and transported by truck to a landfill site. One problem that was experienced was with disposal of toilet paper. In Bolivia, people use to throw their used toilet paper into a bin next to the toilet. If no bin is provided,  the used toilet paper gets thrown on the floor beside the toilet. For communal toilets, this caused both a hygiene risk and a littering problem (OXFAM 2009).