What is a basic, field-applicable method for ensuring safe drinking water?

• A. Boiling water; chemical disinfection (iodine/chlorine dioxide) or portable filtration as alternatives.
• B. Rely on bottled water only
• C. Only chemical disinfection
• D. Only portable filtration

Answer: (A)

In field settings, safe drinking water is achieved with practical methods that work with whatever resources you have. Boiling water is the most universally reliable approach because heat kills bacteria, viruses, and protozoa; once water reaches a rolling boil for a short period, pathogens are inactivated. If boiling isn’t feasible, portable chemical disinfection with iodine or chlorine dioxide provides a flexible alternative that can inactivate a broad range of microbes, though it requires proper contact time and can affect taste. Portable filtration adds another useful option by physically removing many microorganisms and particulates, improving clarity and reducing microbial load, though it may not remove all viruses or dissolved contaminants, so using filtration in combination with disinfection enhances safety. Because field conditions vary, having multiple proven methods available gives the best chance of producing safe drinking water in real-world scenarios.