Drinking water safety is the number one priority during and after any natural disaster — it comes before food and before shelter for survival. Recent storms including Hurricane Helene and Hurricane Milton have highlighted the urgent need for emergency water preparedness. This guide covers what to do before and after hurricanes, floods, and other natural disasters to ensure you have access to clean, safe drinking water.

Recent flooding devastation news coverage in the USA, Europe, Nigeria, Shanghai, and India has highlighted once again the power of water during hurricane, monsoon, and other flooding events.

Be Prepared: Emergency Preparedness: Get a Personal Jase Medical Kit

Hurricane Helene created an 800 mile+ path of destruction across six states (Florida, Georgia, South Carolina, North Carolina, Virginia, and Kentucky) and potentially 4.5 million citizens have been directly or indirectly impacted by this natural disaster. Obvious damages include power lines down, roads destroyed, homes washed away, landslides, and water treatment plants not operational. Less visible is the impact on groundwater — particularly private water wells that need assessment and treatment before any unfiltered or unboiled use.

Pre-Disaster Water Preparedness

Our suggestions are as follows:

1. Try not to panic!
2. Make sure there is at least 1 gallon of clean drinking water per person per day for a minimum of 3 days.
3. Fill a bathtub and other receptacles with water for flushing toilets.
4. Prep a go-bag for evacuation and include: DIY water testing kits and supplies, portable water filter, emergency tablets, matches, pouched drinking water, clean containers, Solar Power Generator, and a portable crank rechargeable radio.
5. Learn the location of local springs and flowing artesian wells and get them tested ahead of the storm as a backup water supply. Also identify emergency evacuation routes and centers in your community. (This does not include surface water sources like streams, ponds, or lakes.) (MORE)

If heavy rains, flooding, hurricanes, or monsoons are expected, maintain a personal fresh water supply for drinking and sanitary needs. The US CDC recommends 1 gallon of clean bottled drinking water per person for at least 3 days. Households should also fill bathtubs with water for flushing toilets.

Some resources for storing and filtering water:

Lifesaver Jerrycan Water Purifier — Military Spec, Heavy Duty Water Purifier for Overlanding, Camping, Hiking, Emergency Preparedness and Survival Kit

EVERLIT Complete 72 Hours Earthquake Bug Out Bag Emergency Survival Kit for Family. Be Prepared for Hurricanes, Floods, Tsunami, Other Disasters (add Lifestraws)

Collapsible Rain Barrel, 100 Gallon Pro Rain Barrels to Collect Rainwater from Gutters, Portable Water Tank Storage Container for Garden Water Catcher with Spigots and Overflow Kit

Emergency Survival Water Distiller and Gravity Filter Combination

Basic Low Cost Gravity Water Filtration System

Post Disaster Water Needs

Following a disaster, safety is priority. Once physical safety is maintained, identifying a method of obtaining clean water is next. During flooding events, water that was once in a stream, lake, or pond may now be severely contaminated with chemicals, pesticides, petroleum products, and human waste. A makeshift filter can remove some color and taste issues — but not health hazards.

Know Your H2O has developed guidance for a makeshift filter that will provide some level of filtration but will NOT remove all chemicals or heavy metals and will ABSOLUTELY NOT treat pathogenic health hazards like protozoa, bacteria, E. coli, Giardia, and other transmittable diseases. This method should only be used in an extreme survival situation. After filtering, water must be boiled at a full rolling boil for 5 minutes. Know Your H2O recommends a full 5-minute rolling boil (3 minutes minimum at elevations above 6,500 feet) to address pathogenic concerns before drinking, preparing food, washing containers, brushing teeth, or any use where water contacts your mouth, eyes, or open skin.

Some reports from the recent southern Appalachia disaster noted that distillation can produce safer drinking water. While distillation addresses pathogens, it does not remove all chemicals or heavy metals, and it strips beneficial minerals. It remains a reasonable option in disaster situations.

Our recommendations for treating survival water from streams, lakes, or ponds:

1. Do not panic!
2. Use stored bottled water first (pouches from your go-bag). Save clean containers for a filtration or storage system.
3. Pre-filtration — Removes discoloration, fine particulates, some organics, and some metals and chemicals, but not all hazards and not pathogenic hazards.
   1. At minimum, use a portable potable water filter, clean cloth, paper towel, or coffee filter.
   2. You can build a DIY makeshift filtration system with an activated carbon layer.
4. Sanitize the water for pathogens:
   1. If you have water sanitization tablets — use them.
   2. If you have 5% unscented chlorine bleach: Add 20 drops (less than 1/2 teaspoon) to every 5 gallons of water. Double the dose if water appears discolored. (Source)
   3. Boil at a full rolling boil for at least 5 minutes (1 minute under 6,500 ft elevation; 3 minutes above 6,500 ft) — or distill if available.
5. Transfer water to clean containers and allow to cool. Shake or mix to improve taste by restoring dissolved gases. Check with DIY water testing kits if available.
6. Store boiled water in clean, sanitized containers with tight covers.

KYH2O Makeshift Filter Instructions: (Sanitization BOIL required after filtering)

Take a 1-liter plastic bottle (soda or beverage). Cut off the bottom leaving about 1 inch of height. Invert the bottle. Cover the open end with cheesecloth or a coffee filter secured with a rubber band.

1. Add a layer of cotton balls, coffee filter, clean towel, or sock to the bottom.
2. Add a layer of crushed charcoal.
3. Add a layer of rinsed, washed fine sand.
4. Add a layer of rinsed, washed coarser sand.
5. Add a layer of clean cloth (if available).
6. Add a layer of rinsed, washed gravel.
7. Cover the gravel with cheesecloth, a coffee filter, or a clean towel.

Website (Reference):
https://www.itsoverflowing.com/diy-water-filter/

You may also want to consider a Portable Distillation System or the Solar Water Heater Distiller — The Sun Kettle.

Solar Pasteurization as an alternative to boiling: Consider making a Solar Water Pasteurization System (pdf) or buying a Solar Oven. Another option is the Solar Clean Water Solutions AquaPak System.

Common temperature indicators for solar pasteurization: beeswax melts at 62°C and soya bean fat melts at 69°C — when these waxes melt, begin timing for sanitization.

Makeshift Water Filter Diagram:

Recovery for Water Well Owners (With Power or Backup Generators)

If your area has been flooded and you use private water wells, you must take action to ensure your well is thoroughly cleaned and sanitized. Contaminated flood water can enter wells directly via the well cap or indirectly through natural macropores in rock or sand and gravel.

Our suggestions are as follows:

1. Do not panic!
2. If you are not handy, contact a licensed professional well driller or a trusted neighbor — they may need help too.
3. If you are handy and have power, inspect the area around the well, remove the well cap, and shock disinfect the well.
4. Purge the well to waste — do not purge into the septic system or back into the well initially. When water appears clear, recirculate back into the well to wash the casing sides. Bypass all water treatment devices and filters and do not run this water through your home's main plumbing.
5. Shock disinfect the well and main line twice. See our guidance on how to shock disinfect a well and the preferred chemical to use. In an emergency, household bleach without scents or additives is acceptable.
6. For the second shock disinfection, include the well and the home distribution system. Remove all aeration devices, bypass all filters, and remove any inline-filtered hoses or connections (e.g., washer hoses). Going forward, consider raising the casing, adding a sanitary well cap, and installing a Well Seal.
7. When shock disinfection is complete, we recommend:
   1. Get your drinking water tested using a DIY Informational Water Testing Kit or by sending a water sample to a laboratory. This is why your go-bag should include DIY water testing kits, a portable water filter, emergency tablets, pouched water, and clean containers.
   2. If testing is not possible, use bottled water for consumption and/or boil your drinking water at a full rolling boil for 5 minutes. Avoid using surface water sources (lakes, streams, springs) directly impacted by the disaster — they are likely contaminated.
   3. If well water or surface water appears cloudy or discolored, allow it to settle as long as possible, then filter through a potable water filter, clean cloth, paper towel, or coffee filter. After additional settling, decant the clear water and boil, disinfect with chlorine solution, or use emergency water tablets. (Note: Boiling and tablets inactivate waterborne pathogens but do not remove dissolved inorganic or organic contaminants.)
   4. Bleach — 5% solution: Add 20 drops (less than 1/2 teaspoon) to every 5 gallons of water; double the dose if water remains discolored. (Source)
   5. Boiling: Bring water to a rolling boil for at least 5 minutes (1 minute under 6,500 ft; 3 minutes above 6,500 ft).
   6. Transfer to clean containers and allow to cool. Shake or mix to improve taste. Check water quality with DIY test kits if available.
   7. Store boiled water in clean, sanitized containers with tight covers.

PS: Adding too much disinfection chemical to the well is not wise — it can cause the release of arsenic and other trace metals into the water.

City Water Customers

If you are a customer of a local water company or authority, the normal distribution system may not be functional — and even if it is, the water may have been contaminated. First step: find out what your local water authority is saying. They may have issued a DO NOT Drink, DO NOT Use, or a Boil Water Advisory — these are three different situations. Learn what each means here.

If a DO NOT Drink or DO NOT USE advisory is in effect, the authority is likely providing access to clean water via bottled water distribution or a local water tanker.

If a Boil Water Advisory is issued:

Do not use your tap water for consumption (DO NOT DRINK!). A boil water advisory means the water may contain a disease-causing pathogen. Establish an alternative water source (bottled or bulk water), or boil water and let it cool before use.

Boil water advisory — what to do:

1. Use bottled water, bulk drinking water, or boiled water that has cooled for drinking, cooking, pet care, brushing teeth, and making baby formula.
2. If bottled water is unavailable, bring water to a full rolling boil for 1 minute (under 6,500 ft elevation) or 3 minutes (above 6,500 ft) — we recommend 5 minutes. Allow to cool, then shake to re-aerate for better taste.
3. You CANNOT just filter your water during a boil water advisory — filtering is NOT adequate. The requirement is to BOIL. After boiling and cooling, filtering is fine. Acceptable supplemental options include a UV filter, portable ozone generation system, portable water filter, or an off-grid reverse osmosis system — but in emergencies, boil first.
4. Do not use ice from an automatic ice maker, even if it has a filter or UV unit. Water must be boiled and cooled before making ice.
5. For infants, breastfeeding is preferred over formula during a boil advisory. If using formula, use ready-to-use formula or bottled water. If you must use tap water, boil (do not microwave or just heat) and cool it. Use boiled water within 72 hours.
6. Use a water screening test on your temporary water source and on your regular source when the advisory is lifted. Follow up with a Level 3 informational screening test via a certified laboratory to confirm lines between the source and your home are free of contaminants.

Other Recent Water-Related Health Concerns

Worms in Well Water

Forever Chemicals in Drinking Water

The Keystone Clean Water Team is a 501(c)(3) that focuses on Pennsylvania but helps private well owners and small water systems worldwide.

For more information, visit our portal. We have a new educational booklet on drinking water quality: "Our Drinking Water".

More questions — visit us at KnowYourH2O.com

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