THIS MAIL SURVEY WAS CONDUCTED FOR THE PURPOSE OF THE COLLECTION OF FIELD EXPERIENCE AND UNPUBLISHED DATA WITH PARTICULAR REFERENCE TO PRACTICAL SOLUTIONS IN DRINKING WATER SUPPLY AND WASTES DISPOSAL IN DEVELOPING COUNTRIES. A NEED WAS FELT FOR A COMPILATION OF INFORMATION OF ALTERNATIVE TECHNIQUES WHICH WOULD BE UNCOMPLICATED, EASY TO WORK WITH, REQUIRE LESS MAINTENANCE, AND WHICH COULD BE MANAGED BY THE LOCAL PEOPLE. THESE COULD BE NON-CURRENT TECHNIQUES, ADAPTIONS OF EXISTING ONES OR NEW DEVELOPMENTS. MADE WIDELY AVAILABLE, SUCH A COMPILATION WOULD ENABLE ENGINEERS TO SELECT THE SOLUTIONS WHICH WOULD BEST SUIT THE SOCIAL, CULTURAL, AND ECONOMIC CONDITIONS OF THE COUNTRY AND TECHNICAL LEVELS OF THEIR PERSONNEL. THIS REPORT, BASED ON THE SURVEY, COVERS WATER SOURCES AND RECOVERY, TREATMENT AND TRANSPORT, SOLAR AND WIND ENERGY, AND COLLECTION AND DISPOSAL.