A great many of the solutions to the clean water and personal hygiene issues facing rural Cambodians require hardware to facilitate their implementation. RDI is actively involved in the process by both designing and building much of the needed equipment and structures. For example, simple and effective organic latrines are being built at homes that have previously had no method of waste disposal available. These latrines consist of two cylindrical holes. One hole is the active side, the other remains unused for a time. A rectangular concrete base is placed over the active hole. In order to keep costs down, the base has no walls but is fitted with four PVC pipes from which modesty screens can be hung. A lid to reduce ambient odor and insect attraction is also provided. A family can use this active side – being careful to sprinkle ash into the hole after each use – until it is filled (about 18 months.) At that time, the base is moved over the other hole which now becomes active. A round concrete lid is placed over the exposed hole and the contents are allowed to compost into usable fertilizer. When the second hole becomes filled, the process is reversed.