All these technologies and others have helped, but each has it drawbacks. Since source water for the most part is not a problem in Cambodia, more that it is not potable the biosand filter has been a very popular approach used in Cambodia. Along with rainwater harvesting I would say these two technologies have had greatest impact in rural Cambodia.
Are there aspects of water sanitation that have been implemented in communities, that still are not functioning to their full potential and could be improved? Are they perhaps functioning to a lesser degree in some parts of Cambodia, more than others, for specific reasons?
With any technology there needs to be monitoring and evaluation. We see especially wells where the pumps are broken making the well useless.
What systems or techniques of water sanitation, if any, are still unexplored and perhaps may have potential to do good?
There are a lot of new technologies…but the problem we see over and over again is that they aren’t sustainable. Either filters need changing or parts need repair and are not available. Also costs are prohibitive. What keeps the biosand filter going is it is built using local materials and once installed rarely needs any maintenance other than swirling the top surface and scooping out the water on top.
What exactly are the bio-filters made out of and how well do they function to remove concentrations of potential toxins? (heavy metals, nitrate, nitrite, arsenic, various pathogens, etc.)
Our filters are made from a steel mold out of cement with a copper tube that runs from the bottom, up the side out the spout. We make them at our office in Siem Reap then truck the filter body out to the villages and bring the media which consists of local gravel and sand. Each filter is installed in one household. Course gravel at the bottom, then a layer of fine gravel followed by the largest layer made of sand. That is it. No moving parts to break. Sand usually never needs replacing, (maybe just a little added due to the cleaning over time). We have filters that are still functioning after 10 years. Biosand filters remove about 99% of protozoa, 95% of bacteria, 80-90% of viruses. They are not very good at removing heavy metals. We do not have issues with Arsenic in Siem Reap province of Cambodia. They also remove iron which we found is more of an issue with the taste of the water and staining clothing etc. than being harmful.
An issue we have explored has been that of water transportation and the time it takes for one to actually get that clean water back to their families. Does Cambodia, for the most part, have nearby sources? How active is the rate of flow from a bio-sand filter to provide clean water and is installation of a number of filters adequate to sustain a community?
For the most part villages have readily available water sources so there is not usually the issue of water transportation. Each filter yields about 60 liters/day. The filter is best used 4-5 times a day. The standing water in the filter is displaced with each use and is the purified portion. We suggest morning, noon, dinner and night. Each filter has a storage bottle with a cap to store the water. A filter is considered a household unit and can supply enough clean water for a family of 6. We find in some cases many more people use the filter than that.
Are the locals able to fix their own equipment for water sanitation should it break or malfunction? How ‘sustainable’ are the devices and services that are implemented?
As I mentioned above we still have filters working over 10 years. We went back and looked at 800 filters we had installed in 2007 and found over 80% were still functioning. Some had been abandoned due to a family moving. Some did need to be restarted (a filter must be used daily and wet at the top). A few did have cracks or clogs of the pipe. In each village we have people we train to problem shoot the basic issues that arise. They call us with a major issue and we come out and fix them (believe it or not they do have cell phones). The key is the simplicity of the filter.
Why are communities that do not have clean drinking water, still without? For example is it a matter of unique terrain or climatic conditions that hinder the same successful techniques used in other parts of Cambodia from from being implemented there? or is it just a matter of funding?
A little bit of all the above. This past year we have been working in a village that literally floods 15 feet every rainy season. Their homes are built on stilts but cannot sustain the weight of the filter. We have designed a base that can hold the filter weight and have started installing them. This adds substantial costs to each filter. Also this village is difficult to access in the rainy season which also make work difficult. Another area we service are the homes on the Tonle Sap Lake in Cambodia. These people live on boats so our filter is too heavy. We have developed a light biosand filter that is made from PVC pipe using the same media. It is not as effective though. We are still fine tuning that one. So also as mentioned before the rainy season floods many villages. In the dry season many villages lose a sizable portion of the population due to them moving to Thailand to work. We have continued to build about 2000 filters a year and are over 15,000 now. Our funding continues to support this.
What logistics, political or social aspects are involved in the work that Water for Cambodia does which may both aid and support, or hinder and provide setbacks to development?
The government of Cambodia is very corrupt. Bribes are a way of life. The rich care little about the poor. The government does little to help the rural villages and seem happy to let us do what we do. We are registered with the government as a Cambodian NGO and follow the rules we are aware of. Nothing is very clear with the government. So far they have left us alone. The Cambodian culture is so different and difficult to work with. They have been through so much with Khmer Rouge and have generations to go before they recover. Women do most of the work. Our staff in Cambodia is all Cambodian except our Operations Manager so that helps with interfacing with the villages and government.
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