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Providing Water to Families in Africa: Water Filter Comparisons

November 25th, 2009 5 comments

A number of people I know have mentioned the Blood:Water Mission and I have even supported a book reading challenge to raise money for that cause (still time to support her!). They are an organization looking to help out Africa. In their own words:

We’re a group of passionate people who have been inspired by our friends in Africa, friends who face unbearable challenges from the HIV/AIDS and water crises. We creatively and thoughtfully raise awareness and the necessary funds for the provision of clean blood and clean water in sub-Saharan Africa.

When they came out with their Christmas Clean Water Challenge, I was very interested in chipping in and helping out. This desire started a very insightful conversation between me, a few friends, and two different water filtration proponents.

The discussion started when Vimal, who has worked with water filtration systems in Africa, was curious about the $85 cost for the biosand water filter through Blood:Water Mission’s Christmas Challenge. This is the conversation that we had (hope you are ok with this Vimal!):

Vimal Shenoy: 85 bucks? How many filters? That’s an expensive filter for developing countries. When I did water filtration work in Africa, our filters cost less than $25 to make and distribute… But whatever.

Matt Jones: Here, watch this video, tell me what you think.

Vimal Shenoy: interesting… if it’s true that it’s good for 20 years, then it may be worth it, though wikipedia only cites 10 years. there’s a lot of factors to consider when choosing water purification means, so I’m not going to diss this means.

Matt Jones: What system did you guys use? I am curious what the differences are and if there are different benefits to either of them. They might be interested in checking out other options as well. Another guy I know used these filters in Haiti and passed on the link. I think this is an important discussion to have because I always get frustrated when non-profs are not using their money wisely. I trust Blood:Water Mission and would love to pass on any other info on what you used.

Vimal Shenoy: yeah, we used potters for peace. I could come downstairs and explain more… but for sam’s sake i’ll put a brief blurb. Basically what we used were what looked like flower pots, the most expensive parts being the plastic pot and spigot. We went to an organization within Benin and taught them how to make them properly and they make them in country with materials there (dirt, coconut shells, whatever else you use in pots). When we left them they were selling them for 25 dollars or so, but we calculated that if they made the plastic parts there, they could sell them for less than 10 dollars, which is a significant difference in that area of the world. Replacement filters after ~10 years is 4-6 dollars, so maintenance is low… take a look at this.

Vimal Shenoy: the greatest downside is the rate of water filtration. only 2.5 liter per hour as opposed to 40 in the other system. but if you distribute these on a household level, they are definitely worthwhile. 2.5 litres x 10 hours is enough for everyone to drink in a household.

Matt Jones: Awesome! That is good information to have. I imagine that the most expensive part of the biosand filters is the “biological layer” (whatever that is). I will definitely pass that on. I am assuming they have looked at other options as well, but have other options available is always good.

As you suggest, there could definitely be benefits to either system and context probably means a lot. It would be good to hear from the organization about how they picked this particular method.

Matt Jones: Got a pretty good response from the Blood:Water Mission people, here is a part:

“As a part of this program, every family wanting filter sends a family member to a three day training held at the compound. As a part of this training, the family member learns about biosand filters, how to maintain the filter, as well as the basics of hygiene & sanitation (there are complete hygiene & sanitation trainings done in villages separate of this training). They also make their own biosand filter, which is then installed in their home at the end of the week. This is a much more intensive process in terms of space, personnel, and time than is typically used in biosand filter programs, but we have found that it is very effective in terms of local empowerment and sustainability. This cost also pays for some follow-up from staff to make sure that everything taught in the training is being implemented in the homes.”

Vimal Shenoy: ah very good. i see now why the cost is somewhat elevated. but with that follow up that’s really good. interesting.

Matt Jones: Indeed. I suppose the important part is not just the cost of the filter at all, but the cost of training and providing resources to help with sustainability and positive practices.

Matt Jones: I just got this from Potters for Peace:

“On our website there is a comparison study, at least one, on the ¨filters¨ sub page ¨studies¨ Yes, the ceramic filter is less expensive, the price varies but generally retails for $15-$25 ready to use with sustainable profit and all costs included. The ceramic filter also usually is more effective at removing bacteria than the bio-sand. One could argue also that the ceramic filter is more user friendly in terms of maintenance. The idea of using terra cotta clay for water treatment is easily accepted and something with a long history in the developing world, many users claim that they prefer the taste of water passed through clay.”

Here is the link to the study he mentioned.

The study was actually quite interesting, you should read it. I am actually going to write up a post about all of this actually, it has been quite helpful.

I would recommend reading the study: Comparative Analysis of the Filtron and Biosand Water Filters. Here is their conclusion:

The Filtron [the ceramic Potters for Peace filter] is more effective in removing E. coli and total coliformes than the biosand filter, but a flow rate of only 1-2 liters per hour and the frequent need for cleaning limit its ability to meet UN minimum requirements. The biosand filter’s flow rate is adequate to meet this standard for quantity, but not consistently for quality, as defined by the WHO. It is, therefore recommended that the filtered water from the biosand filter be disinfected in some manner, such as UV radiation or chlorination, before being consumed.

The cost of the Biosand filter is more expensive but can handle a larger load, but the Filtron system seems to remove bacteria better. One comment from the study suggests that the biological layer (the “schmutzdecke“) of the Biosand filter could take time before it becomes most effective (they saw better and more consistent results near the end of the trial). Also, a disadvantage to the Filtron system (aside from the lower flow rate) is that it requires frequent cleaning to be effective. This could be a huge problem for areas that not only have contaminated water, but small amounts of water.

Anecdotally, both filters have support. Vimal has personal, positive experiences with the Potters for Peace ceramic filters and Nathan had this to say:

biosand is overall the best for family/in-house use. its super simple, super low maintenance, and with a little training can last for 20 years with no costs. so… i’ve yet to hear of anything that can beat that… it’s because it mainly uses a biological layer to eat all the nasty bacteria… however, it does not filter pesticides and other chemicals… which are not usually present in 3rd world countries… so its usually highly effective

Clearly, there are a lot of factors that go into choosing a filter and providing support that goes along with it.

I am still sold on supporting Blood:Water Mission’s Christmas Challenge. I want to purchase at least one Biodsand filter and have a few people already willing to help out. I would love to purchase more, so please let me know if you are interested in helping. My family is also interested in supporting this cause sometime this year (as a group we are supporting Heifer International this Christmas). If you would like to join me, please let me know and I can coordinate OR feel free to donate directly to them or to their Christmas Challenge. OR, if you feel the Potters for Peace method is more to your liking, you should donate directly to them. Either way, I highly recommend that you be giving this Christmas season (and all year really) and spending less on “things.”