How to Make Water Safe to Drink During Natural Disasters

Posted by
John Woodard on February 16, 2024

According to UNICEF, about 74 percent of all natural disasters are water related, meaning they can have an impact on water supplies. Many types of natural disasters and other emergencies can affect your home’s drinking water. Planning ahead to counter these situations is not always possible or practical, but there are many measures homeowners can take to prepare their water supplies for potential contamination. For those that do not have the means to prepare with full water treatment systems, some common household items can create water that is safe to drink when it is affected by a natural disaster. In this article, you can learn how to prepare your home’s water supply ahead of an emergency and how to treat contaminated water at home in a pinch. Keep in mind that the advice present in this article is not intended to replace the guidance of your local authorities during a natural disaster.

The critical importance of preparing water for emergencies

Unlike food, which humans can survive without for weeks, water is a necessity that humans can only survive for a few days without. When water supplies are compromised, the well-being of those who use the water supply is put in immediate jeopardy. Preparing your home’s water supply for emergencies ensures that your family will have access to clean, safe drinking water in times of natural disasters or emergencies.

What natural disasters affect water supplies?

Many natural disasters, including floods, hurricanes, earthquakes, tsunamis, and tornadoes, can cause a water supply to become contaminated. For example, flooding can contaminate private wells, lakes, rivers, and other freshwater sources with bacteria, human waste, chemicals, and other harmful contaminants. On the other hand, earthquakes can cause damage to freshwater and sewer lines, leading to contamination of the public water supply. Regardless of the natural disaster, there are steps you can take to mitigate the effect on your home’s water.

Should I store water for emergencies?

During an emergency, bottled water is the safest form of water to drink. If you store water ahead of time, you do not need to rely on water treatment systems that require electricity, and you do not have to worry about the contaminants in your drinking water. Waiting until right before a natural disaster strikes to purchase bottled water is risky, as there may not be enough supply to meet the demand of customers needing access to clean drinking water. Keeping an emergency supply of bottled water can alleviate some of the headache provided by a natural disaster.

The CDC recommends storing at least one gallon of water per person per day for an emergency. You should try to keep a stockpile that can supply you for at least two weeks. This means that a family of four should keep an emergency water storage of at least 56 gallons (14 days x 4 people x 1 gallon per day per person). If you live in a hot climate, have pets, or live with someone who is pregnant, you should stock more than one gallon per person. You should also keep a bottled of unscented chlorine bleach to disinfect water in case of emergency.

How to prepare your home’s water for natural disasters

The best thing you can do for your home’s water supply is to prepare before crisis strikes. Once your water becomes compromised, you do not have time to wait around for a solution. Rather, you should already have systems in place to make your water safe to drink. If your water supply is already contaminated, there are some emergency steps you can take that will make your water safe in some situations. In other situations, you cannot make your water safe to drink with an emergency solution at home, meaning you must resort to another source of water, such as bottled water.

Municipal water supplies are treated to remove microbial threats, but, during natural disasters, they can be contaminated with bacteria, viruses, and parasites. During these situations, a home water treatment system can make your water safe to drink without the need for boiling water or other disinfection methods. Some home water treatment systems can make your water safe to drink by themselves, while others must work in conjunction with another system or two to effectively treat water. Below are some water treatment systems that can make water safe to drink during an emergency either by themselves or with the help of another system.

Water distillers

Water distillers are heralded as the most effective way to make water as pure as possible. This is because they remove practically all contaminants from water. Distillation is so effective that it is the only acceptable water for certain medical and laboratory applications. Regardless of the contaminants present in your water, a properly used water distiller can make the water safe to drink. This makes distillation particularly effective during natural disasters when you do not always know the specific contaminants in your water.

Water distillers emulate the hydrologic cycle that circulates water between the sky and the earth. Contaminated water is loaded into a chamber, where it is heated until it turns into vapor. This vapor collected at the top of the distiller, where it is cooled back into a liquid state. Because contaminants and water vaporize at different temperatures, the water collected at the top of a distiller is pure water. The bacteria, chemicals, and other contaminants remain in the boiling chamber. The pure water at the top of the distiller is diverted into a collection container. From here, the water can be used for drinking, cooking, or any other application where pure water is needed. Because water in a distiller must vaporize, cool down, and be diverted into a collection container, the distillation process is very slow. It takes about 4 to 6 hours for a countertop distiller to treat one gallon of water. Because water must be heated constantly in a distiller, distillation uses more energy to treat water than other systems.

Learn more: What is distilled water and is it safe to drink?

Advantages of water distillers

  • Create very clean water
  • Do not require the aid of other systems

Disadvantages of water distillers

  • Slow treatment rate
  • Use more energy than other treatment systems
  • Require electricity
  • Produce water with a dull, flat taste

UV water disinfection systems

UV disinfection systems are common in homes that use well water because they effectively deactivate microorganisms in water. UV systems disinfect water by subjecting it to a germicidal wavelength of UVC light. This light contains a very short wavelength that is harmful to humans, animals, and, for our purposes, microorganisms. UVC light damages the DNA of microorganisms, preventing the organisms from replicating and further contaminating a water supply. This also means that the bacteria, viruses, and other microorganisms in the water cannot reproduce once consumed, effectively preventing waterborne illness. UV disinfection systems only subject water to UVC light, meaning they do not remove any contaminants from water. If you need to remove other contaminants from water, consider pairing your UV system with a reverse osmosis system.

UV disinfection systems are not effective when sediment and other small debris blocks the UVC light from reaching microorganisms in water. Because of this, a sediment filter must always be used before a UV system.

Learn more: What is a UV water purifier and how does it work?

Advantages of UV disinfection systems

  • Treat much higher volumes of water than distillers
  • Disinfect all water that enters a home

Disadvantages of UV disinfection systems

  • Must be used with a sediment filter
  • Do not remove any contaminants from water
  • Require electricity

Reverse osmosis systems

Reverse osmosis (RO) is a popular home water treatment method because it effectively removes many contaminants from water. They are almost always used in point-of-use applications, meaning they are only connected to one water outlet, most commonly the kitchen sink. If needed, reverse osmosis systems are also available in whole-house configurations, treating all water that enters a home. RO removes practically all contaminants from water, making it almost as effective as distillation. However, certain contaminants, such as some organic compounds, select microorganisms, and some dissolved gases are not removed by reverse osmosis. This means that RO should be used in conjunction with a disinfection treatment method, such as a UV system.

Learn more: What is a reverse osmosis system? | Do I need a whole-house reverse osmosis system?

Advantages of reverse osmosis systems

  • Remove many contaminants from water
  • Available in point-of-use and whole-house configurations

Disadvantages of reverse osmosis systems

  • Create wastewater in the treatment process
  • Do not make water microbiologically safe

Sediment filters

Sediment filters, as their name suggests, remove sediment, dirt, and other small debris from water. They are often used as a pretreatment method so that other filtration systems do not become clogged. Sediment filters are essential to other water treatment systems like UV and reverse osmosis. RO systems contain a sediment filter as one of their treatment stages, while UV systems require a separate sediment filter to function properly.

Sediment filters are simpler than many other water treatment methods. As a result, they are much less expensive than other systems. Sediment filters alone will not be able to make your water safe to drink, but they are an excellent first step in a robust water treatment system.

Learn more: What is a sediment filter and how does it work?

Advantages of sediment filters

  • Inexpensive
  • Effectively remove sediment, dirt, and other small debris from water
  • Prevent other water treatment systems from clogging

Disadvantages of sediment filters

  • Cannot make water safe to drink on their own
  • Only remove large contaminants

How to quickly treat contaminated water at home

If your water is already contaminated and you do not have access to bottled water or another clean water source, you must be able to treat your home’s water with easily accessible items. Below are some steps you can take to purify water at home with items you may have on hand.

Boiling water

Boiling water is the most common method of disinfecting water because it only requires a working stove or other heating mechanism. To effectively eliminate microorganisms from water, bring water to a rolling boil for at least one minute if your elevation is below 6500 feet. If your elevation is higher, bring the water to a rolling boil for at least three minutes. Before pouring your water into a clean storage container, allow the water to cool to room temperature.

Keep in mind that boiling water kills microorganisms, but it will not eliminate other contaminants, such as heavy metals, salts, and chemicals, from your water. In fact, boiling water will cause the volume of water in your pot to decrease as some of it is lost to steam. This means the concentrations of these contaminants will be slightly higher than before the water was boiled.

If you do not have power during an emergency where your water contains microorganisms, try one of the below methods to disinfect your home’s water.

Learn more: Boil water advisory procedures

Purification tablets

Water purifier tablets are most often used for recreational purposes like hiking or camping, but they can also be used in emergency situations where water has become contaminated with microorganisms. These tablets use chlorine or iodine to kill harmful bacteria in water, preventing waterborne illnesses. While iodine tablets are excellent at disinfecting water, they can cause adverse health effects if used for an extended time, particularly in pregnant women or people with thyroid problems. They also give treated water a foul aftertaste. As a result, chlorine tablets are a popular option for those that do not want the aftertaste or possible side effects of iodine tablets.

When using a water purifier tablet, ensure you strictly follow the treatment instructions for your tablets. If you attempt to cut corners, such as not letting the tablet treat the water for long enough before consuming, you can expose yourself to harmful microorganisms.

Use unscented chlorine bleach

In a pinch, unscented household bleach can be used to disinfect your drinking water. Ensure that you use chlorine bleach that can be used as a disinfectant. For each gallon of water, add about 1/8 teaspoon (8 drops) of bleach. Mix the solution and allow it to sit for thirty minutes. If the water is cloudy after stirring, repeat the process again. While your water may contain a strange odor, it is safe to consume if you used the correct amount and type of bleach. When using bleach, always pour it in a well-ventilated room and avoid contact with your skin, eyes, or any other body parts.


If you have any additional questions, please do not hesitate to contact us.

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