Trailblazer Foundation

a U.S. tax exempt public charity

Benjamin Gooding, Program Director
Phone: 092 209 874

 

 

Clean water, who needs it?

 

 
Typical drinking water source in rural villages.

 
Tonle Sap lake water being used at Chong Khneas Floating School.

 

Cambodia is one of the poorest countries in S.E. Asia and continues to be affected by waterborne illness on a daily basis. Larger scale water treatment plants and drilled wells are financially unfeasible in some communities and can take much time to achieve while many families continue to suffer from water related illness and death. Bio-sand water filtration is a sustainable, low cost, low maintenance technology that can be constructed by locals with locally available materials such as sand, gravel and concrete.  Its success has been documented around the world by improving overall health in the community. It is a chemical free method of producing clean drinking water that is virtually free of bacteria and viruses.

Operation is simple. Water is dumped into the top of the filter onto a diffuser plate which protects the bio-sand layer. It then flows through a layer of biologically active sand which traps and degrades sediment, bacteria and parasites. Due to the availability of incoming organics (food) and oxygen at the top of the sand layer, naturally occurring micro-organisms colonize, grow and function to break down organic matter and destroy incoming fecal bacteria and viruses.

Over a 6 year average from collected data from Nepal, Vietnam, Honduras, Pakistan, and Cambodia the levels of water contaminant removal are as follows:

Bacteria…….90 to 99.99%

Viruses……..99%

Protozoa……99%           

Parasites……100%           

Iron………....93%

Arsenic….….85-95% (by adding 5 kg of iron nails to the diffuser basin)

Typically the bio-sand filter will remove over 98% of the bacteria and parasites if installed and used properly. Often the amount of bacteria left alive will not be enough to make someone sick. Disinfection using chlorine, or solar rays from the sun, is recommended to remove any remaining bacteria.  The important feature of the bio-sand filter is that it is an intermittent use sand filter unlike the traditional slow sand filter which requires continuous use. When the filter is not being used the water remains at a level above the sand bed to keep the biologically active sand wet. To maintain optimal use of the filter it is recommended that no more than 50 to 80 liters of water is filtered per day.

Maintenance is very simple and within the capabilities of any user. Washing the top few centimeters of sand will restore the proper filtration rate of 1 litre per minute. Maintenance cost over a 3 year average is about $1.00 (U.S.) per year. Trailblazer Foundation gives an onsite lesson and a handout which has been translated and explains proper use, maintenance and sanitation practices for optimum use of the bio-sand filter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Construction of bio-sand water filter.
Delivery of water filter to Pray Dack village.

 

 

back to goneawol.net