Self-reliance in water treatment: Providing safe drinking water to
communities using charcoal filtration to remove pesticides
Judith Flanagan, University of New South Wales, Australia firstname.lastname@example.org
Joshua Kearns, AqueousSolutions, Oakland, California, USA and Chiang Mai province,
Pesticide contamination of drinking water is a significant problem in developing countries where
due to inadequate regulations over 70% of agrichemicals used intensively are banned or heavily
restricted in the West. Pun Pun organic farming community in northern Thailand is committed to
practicing a variety of sustainable and self-reliant living techniques. A reservoir nearby is
contaminated by agricultural (including pesticide) runoff from surrounding farms. We are
developing a simple, robust and inexpensive technology to purify water thus providing the Pun
Pun community with a stable, year-round source of safe drinking water using locally sourced
labor and materials.
The environmental and human health consequences of widespread application of large quantities
of hazardous agrichemicals are a mounting concern around the globe. In the United States, for
example, a recent study by the Center for Disease Control detected pesticides and their
breakdown products in 100% of test subjects. The highest concentrations of many agrichemicals
were detected in women of childbearing age, children and Mexican Americans (1).
The situation in the developing world is even worse, where agrichemical corporations find
markets for many of their products deemed too hazardous to human health and the environment
for sale in Western countries. For example, each year the US produces hundreds of millions of
pounds of pesticides considered too dangerous for domestic use. Meanwhile, over 70 percent of
the pesticides used in Thailand and India are banned or severely restricted in the West (2). A
survey by the Thai National Environment Board found residues in 86 percent of water samples
(3). Furthermore, in the Indian state of Punjab DDT and BHC – agrichemicals banned in the west
– have been widely detected human breast milk (4).
A survey of the agrichemical products in common usage around the Pun Pun community in
northern Thailand revealed that, out of 34 substances, 19 exhibit moderate to highly acute
toxicity to humans, 8 are possible human carcinogens and 5 are known human carcinogens, 9 are
cholinesterase inhibitors (indicating neurotoxicity), 10 are suspected endocrine disruptors, 6 are
reproductive or developmental toxins, 21 are classified as “Bad Actors” by the Pesticide Action
, and 13 represent significant threats to groundwater contamination.
According to the Pesticide Action Network, “Bad Actors” are chemicals that exhibit one or more of the following