Sand-filters: a sustainable answer to potable water issues in Haiti
ACTED uses a large scale bio-mechanic filtration technology in Haiti, in the Lower Artibonite.
Despite considerable water resources in Haiti, only 55% of the households have access to potable water (according to a 2008 UNICEF report). An aggravated erosion of the soils, frequent floods, the absence of sanitation systems, latrines and solid waste management, explain both the shortage in ground water and the pollution of surface waters (rivers, sources, etc). The population, which draws its water from the polluted Artibonite River and its surrounding irrigation canals, in the Lower Artibonite zone, is therefore daily confronted to these issues. In response, ACTED has distributed sand-filters to 1,200 households in the townships of Grande Saline, Desdunes and the 5th Bocozelles section of Saint Marc (since May 2009), with the support of both the European Union and UNICEF. 1,500 additional sand-filters should also be distributed at the end of 2009 in the rural and isolated areas of the Lower Artibonite.
Access to potable water has recently considerably deteriorated in the Lower Artibonite. The salinization of ground waters, due to the soils gradual sinking, has compromised the use of artesian wells. Although some Hydropur stations created by Oxfam remain available, they are unequally spread in the zone, thus limiting their access by the population. Hydropur stations combine bio-mechanic filtration and the chlorination of water. They can provide up to 1,000 people with potable water on a daily basis. The first hydropur stations were installed in Haiti in 1984. Potable water conveyances are also insufficient, and because of their outdated state, they fail to guarantee the cleanliness of the water. Therefore, the consumption of contaminated water is a major sanitary risk, particularly for pregnant women and children under 5.
The latest national sanitary survey (EMMUS IV) indeed reveals a high rate of diarrhea for children under 5 year old in the Artibonite department (36%) in comparison to the national average (23%). As drinking water is conducive to the spread of these illnesses, it is crucial to render drinking water shipments safe.
The river as the main source of water
The Artibonite River is the unique accessible and free source of water for the nearby communities. Understandably, the families in the village of Lagrange use it regularly for diverse purposes (to cook, to shower, or to wash their clothes). The water they drink is brackish and salty. As a consequence, the inhabitants regularly suffer from diarrhea, skin infection and stomach pain. Edner Louis, father of eight in the area of Lagrange, explains: “My wife Denise and our two little children [Fedline, 4 year old and Odlin, 13 year old] often developed diarrheas during the last four months [in the rainy season], particularly when they drank water from the river”. People in Modelle village use the water from the Boudette-Modelle drainpipes, filled with waste and silt. The river, the secondary irrigation canals and the drains are the unique sources of water in the isolated rural areas of the Lower Artibonite. They are as much used for domestic cleaning and showering as for livestock drinking, thus explaining the frequency of hydric illnesses. “We only have the muddy water of the river available”, Louis tells us. “And although we usually leave it to settle before drinking it, this is obviously not enough: the children suffer from diarrheas and horrible stomach pains.”
A layer of sand retains the particles between the sand grains.
Slowly filtered through the sand, the water generates new micro-organisms within the first centimetres of the sand layer which reduces bacteria and pathogenic residual that remain in the water.
The filtration process
In these particular circumstances, domestic water filtration is thus the best means to guarantee access to potable water in the isolated rural zones of Lower Artibonite. Beneficiaries have rapidly adopted this technology, as coffee and fabric filters are traditionally used by the majority of the population. The water treatment process is based on a double filtration mechanism, mechanical and biological, which guarantees the cleanliness of the water at 99.9% (see box below).
Sand-filters are easy to use and require little maintenance. Moreover, lasting up to five years, they are sustainable sources of potable water for the beneficiary households. Eman Oxide Chéry, father of a family of 10 children in a precarious economic situation, certifies that filters are very advantageous: “Thanks to the filter, we have free processed water and don’t need to gather wood to boil it. As a result, the children are less sick and we save money by spending less on chlorine or on char-coal to filter water”.
SUPPORT TO LOCAL CAPACITIES
In close partnership with the Support to Human Development Initiatives Programme (PAIDEH), a Haitian NGO which runs on micro-entrepreneurship, ACTED currently works at the fabrication and promotion of sand-filters. For a long time, the Centre for Affordable Water and Sanitation Technologies (CAWST) has supported PAIDEH, and contributed to setting up a fast and rigorous production process. Thanks to ACTED and PAIDEH’s previous collaborations, 86 jobs have been created in the PAIDEH independent workshops. New orders have allowed the sustainability of these jobs for the year 2010. In parallel, ACTED works at the institutional consolidation of PAIDEH to improve the monitoring of the beneficiaries. This includes the training of 10 workshop technicians, the repair of broken moulds, the reinforcement of PAIDEH beneficiaries’ monitoring system, the training on filters’ maintenance technique based on the PHAST method as well as the training by CAWST of ACTED technical teams.
Beyond the distribution of filters, trainings on their use and maintenance, and a close monitoring of the beneficiaries are essential to guarantee an optimal use (see box above). Along with the distribution of filters, trainings on eight key maintenance points as well as an explanatory booklet in Creole are provided to the beneficiaries. According to Charles Mitila, one of the programme’s beneficiaries, this training was essential: “Thanks to the training, the use and maintenance of the sand-filter is now easy. Without training, it would have been quite difficult to do it correctly”.
Because of both the severe problems related to the extraction of ground water and the pollution of surface waters in the Lower Artibonite, alternative measures such as sand-filters for households and a mix between impluviums and filters for public infrastructure (schools, health clinics) appear as most suitable. In addition to the dissemination of this technology, sensitization activities in regard to water hygiene and the prevention of hydric illnesses as well as latrine building programmes for the riverside residents are also carried out. ACTED therefore strives to respond in the short term to the issues related to potable water and sanitation in the townships of Grande Saline and Saint Marc in the Lower Artibonite.
ISSUES IN THE DEFINITION OF POTABLE WATER
The SPHERE (Humanitarian Charter and Minimum Standard in Disaster Response) standards state that access to potable water should guarantee “0 Fecal Coliform per 100 ml of water”. An eight points control set up by CAWST allows the PAIDEH filters to guarantee quality water, potable at 99,9%. Still, considering the initial water is extremely contaminated and contains 1000 coliforms, 1 or 2 will inevitably remain, despite the filtration process.
In its « Guidelines for Drinking-water Quality », the World Health Organization (WHO) states that the SPHERE standards however depend on the area of intervention. In Haiti, reaching 0 coliform would necessitate the definite end in human waste pollution of the water. This contingency is however only expectable in the long term and through coercive policies.
In addition, the “0 Fecal Coliform per 100 ml of water” SPHERE standard is not the unique indicator to certify of the cleanliness of the water. Additional pathogen factors need to be considered in light of the contamination of drinking water. These are: the quantity of water that is offered, the price the beneficiaries pay for their water (they will disregard cleanliness if they can pay less), the accessibility of the water (similarly, beneficiaries will prioritize accessibility at the detriment of cleanliness), as well as the reliability of water shipments.