bio sand water filter
July 30, 2010
Simple, Accessible, Affordable Tests to Assess Microbial Water Quality and Safety in the Developing and Developed World “My hope is that these tests would be transformational. […]
July 22, 2010
A dirt cheap and 100 percent ecological house that has all the comforts of an ordinary home, without being connected to the electricity grid, waterworks, sewer […]