When tap water safety is compromised, such as during emergencies or when a water source’s quality is uncertain, sanitizing drinking water becomes important. Contaminated water can harbor harmful microorganisms, including bacteria, viruses, and parasites, leading to waterborne illnesses. These pathogens can cause conditions from mild gastrointestinal issues to life-threatening complications.
Disinfecting water eliminates these disease-causing organisms. Household liquid bleach is an accessible and effective solution for emergency water treatment. Bleach works by releasing free chlorine, which oxidizes and inactivates pathogens, making the water safer for consumption.
Selecting Appropriate Bleach
Choosing the correct type of bleach is crucial for effective and safe water purification. Only regular, unscented, plain household liquid bleach should be used. Check the product label to ensure the active ingredient is sodium hypochlorite.
Avoid scented, color-safe, splash-less, or gel bleach varieties, and those with added cleaners. These often contain additional chemicals unsafe for ingestion. Suitable household bleach typically has a sodium hypochlorite concentration ranging from 5% to 6% or 8.25%.
Determining Bleach Dosage
Determining the appropriate bleach dosage is crucial for water sanitization. The amount needed depends on the water volume and clarity. Clear water requires less bleach than cloudy or turbid water, which needs a higher concentration for effective disinfection.
For clear water, add 8 drops of 6% sodium hypochlorite bleach, or 6 drops of 8.25% bleach, per gallon. If using a 5.25% sodium hypochlorite concentration, 8 drops (0.5 mL) per gallon is recommended. For smaller quantities, such as a quart of clear water, 2 drops of 5.25% household bleach are sufficient.
When treating cloudy or very cold water, double the dosage. This accounts for interference from suspended particles and organic matter. For instance, cloudy water requires 16 drops of 6% bleach per gallon. Filter visibly cloudy water through a clean cloth or coffee filter before adding bleach to improve disinfection efficacy.
Applying Bleach for Treatment
Once the correct bleach dosage has been determined, carefully apply it to the water. Begin by adding the measured amount of unscented liquid household bleach directly to the water in a clean container. It is important to use a medicine dropper or a clean teaspoon for precise measurement, especially for smaller volumes.
After adding the bleach, thoroughly stir the water to ensure the disinfectant is evenly distributed throughout the entire volume. This mixing allows the sodium hypochlorite to effectively contact and inactivate microorganisms present in the water. The treated water should then be left to stand for at least 30 minutes to allow the chlorine sufficient contact time.
Following the 30-minute waiting period, verify the effectiveness of the treatment by checking for a faint chlorine odor, similar to that of a swimming pool. This slight smell indicates that enough chlorine remains in the water to have achieved disinfection. If no chlorine odor is detected, repeat the dosage and allow the water to stand for an additional 15 minutes before rechecking.
Ensuring Safety and Proper Storage
Handling bleach requires certain safety precautions to prevent accidental exposure. Always use bleach in a well-ventilated area to avoid inhaling fumes and prevent direct skin or eye contact. If contact occurs, immediately rinse the affected area with plenty of water. Bleach is corrosive and can cause tissue damage if ingested in concentrated forms.
After the water has been successfully treated and a faint chlorine odor is present, it is ready for safe consumption. Store the disinfected water in clean, sanitized containers with tight-fitting covers to prevent recontamination. While bleach effectively kills most disease-causing microorganisms, it is important to remember that it does not remove chemical pollutants, heavy metals, or other toxic substances from the water.
If the treated water has an overly strong chlorine taste, it can be mitigated by pouring the water back and forth between two clean containers several times, or by letting it stand uncovered for a few hours. This aeration process helps to dissipate some of the residual chlorine. However, this method should only be used after the necessary contact time has passed and disinfection is complete.