I always enjoy presenting to the students at MIIS and local residents who grow vegetables in the community garden their.  The students pursuing graduate degrees are interesting and well traveled.  This year several of the group had volunteered in Madagascar and Indonesia and were able to learn first hand the challenges of water born illnesses in 3rd world countries.  In the United States many cities and states have policies allowing rainwater to be captured and processed into potable water.  Generally this requires expensive equipment to remove sediment and disinfect the water prior to being potable.  One student and her friend told me how local folks in Indonesia captured rainwater and used a tank full of sand to remove sediment before flowing into the second tank.  From the second tank the water was put into plastic bottles and laid out in the sun while ultraviolet light killed the bacteria and virus and made it potable.  Very different, but very effective and used my millions of people around the world.  In fact, the World Health Organization recommends solar disinfection as an effective way to eliminate water born disease.  For more information on solar disinfection, google SODIS.  The community garden at MIIS is very impressive and well organized by the student volunteers.  There are separate plots that are used by different individuals or families to grow food.  The garden also practices composting and vermiculture.  Water for the garden is provided by two sources, Cal-Am, and a 3,000 gallon rainwater tank capturing rainfall from the classroom roof.