Which water filtration/treatment systems/products could we supply after a natural disaster?
This is a question that I've been asked in the field so I wanted to share it with everyone on KnowledgePoint
This question was asked by a private company who planned to assist the victims of the hurricane in Puerto Rico.
Wondering if you might be able to opine on which water filtration systems/products you may have vetted/trust. We’ve received recommendations on the following:
You have here a wide range of different products, most of them being household water treatment (HHWT) solutions that could be used during emergency responses, when sources of potable water are not available; but one – from Water Makers – being a reverse osmosis desalinization system.
Then the choice depends on your objectives:
Why do you want to treat water? What are the available sources of drinking water? How many people are affected? After the emergency response – during which portable water treatment kits could be used, what longer term solution are you planning for drinking water? What is your budget available? And finally, which system/technology would be accepted by the users?
Firstly, before making any choice, keep in mind that the chlorine, when properly used and dosed, has, what we call a “persistent effect”: you always add a little bit more of chlorine than needed, to make sure that you have some free residual chlorine in your water.
During emergency response, when people might be exposed to diseases or outbreak and/or when hygienic practices of people are not healthy, the drinking water could be re-contaminated after treatment – i.e. through dirty hands or buckets. So, even if the water has been filtered using Waves for Water or Sawyer filters, it could be contaminated afterwards, through risky hygienic practices. Thus, purification tablets/chlorine tablets (supplied with the Dayone response water bag and by the internationally known Aquatabs offering a wide range of products) would properly treat your water and a remaining/extra quantity of chlorine present – called “residual chlorine” – in the treated water would prevent opportunistic re-contaminations.
Even if you’re working in an environment where the hygienic practices seem to be good, I would recommend the use of chlorine for the treatment of water, which could be combined to the filtration: first, filter the water (which will remove lots of contaminants and suspended matters) and then disinfect it (the filtration would reduce the quantity of chlorine required to treat the water) making sure that you’ll have “free residual chlorine” after treatment.
Of course, if you’re looking for a system that you may use during your treks in the pristine mountains, you can use the filter bags without chlorine to filter the water from the torrents!
Cost and time
Remember that if you plan to distribute massively HHWT technologies, you’ll need to properly train the users and monitor the use. Then, when you target a large number of affected population, it will be more expensive to organize a distribution of HHWT technologies than to protect and use a source of good quality water. But during an emergency response, it could be the only solution; which should be a temporary solution.
Chlorination at the points of use
Under extreme conditions, you may need to set up water treatment at the point of use. It’s quite common during cholera/Ebola outbreak. You’ll set up different chlorination points which consist of some trained technicians chlorinating the collected water directly ... (more)
Aqua tabs are are simply fixed dose chlorine tablets. To be effective the turbidity of the watter must be below 5 NTU. Unless your water is coming from protected wells you would need to filter the water. IF water is coming from surface water sources such as rivers then you would likely need to include a cosgulation/flocculation stage. For individual/household levels you could try combined treatment sachets. There are a number of proprietary brands, I think ther is a south african producer called waterguard, and a European producer called aquapur. There are likely to be a myriad of Indian producers. I suggest that you check out the Oxfam equipment catalogue at https://supplycentre.oxfam.org.uk/wat..., which provides a comprehensive set of options, many of which are purposefully designed for deployment in a humanitarian emergency.
Hello the question you ask comes from a disaster situation. It is therefore very difficult to provide a truly reliable solution. Everything will depend on several factors of origin of the natural disaster and the origin of the water to be treated. Earthquake, flood. Earthquake: It can be considered that pollution comes from the gullying of the soil in the water. Filtration systems are highly operational to date Flooding: This is more serious because all terrestrial pollution can have contaminated this water. It is then necessary to study the possible sources of pollution, their toxicity and adapt a targeted treatment. We are dealing with a much more important issue that requires funding to meet the objectives. Too broad a subject to answer.
Water Mission has utilized a system over the past 15+ years that brings safe, filtered, disinfected water to a community. It has been designed for ease of deployment in disasters (given all the challenging factors in these scenarios).
More information including a process schematic: https://watermission.org/wp-content/u...
Not a direct answer to the question, but a comment/ feedback on the phrasing of the question itself: disasters are not natural ... hazards may be, but whether a hazard turns into a disaster is the consequence of global/ regional/ local geopolitical/ economical factors ... labelling disasters 'natural' takes away from the need for relevant players to take responsibility for the role they played in making a hazard into a disaster ....
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