Household Water Treatment in Flood-Affected Areas

After a flood, the safest household treatment for the muddy water people are actually drinking is coagulation-flocculation-disinfection, not a chlorine tablet on its own. A P&G Purifier of Water sachet treats 10 litres by settling out the suspended solids and then disinfecting, removing the Giardia and Cryptosporidium that resist chlorine alone, per the CDC-affiliated Center for Safe Drinking Water. On turbid floodwater, that is what works.

Why is flood water so dangerous to drink?

Floods do two things at once: they overwhelm sanitation and they fill every water source with suspended solids. Latrines, animal waste, and surface runoff move straight into the shallow wells, ponds, and rivers that displaced households fall back on, and the water arrives brown with silt and organic load. That combination is exactly what drives waterborne disease. Microbiologically contaminated drinking water causes roughly 505,000 diarrhoeal deaths each year, and 2.2 billion people lacked safely managed drinking water in 2022, per the WHO drinking-water fact sheet. In children under five, about 88% of diarrhoeal deaths are attributable to unsafe water, sanitation, and hygiene, per CDC Global WASH.

The scale of the exposure in South Sudan is not abstract. Flooding affected over 1.4 million people across 44 counties and displaced more than 379,000 in 2024, with renewed flooding affecting around 1.3 million and displacing roughly 335,000 in 2025, Jonglei worst-hit, per OCHA South Sudan. Those floods landed on top of an active cholera outbreak that reached nearly 100,000 suspected cases and more than 1,500 deaths across 55 counties from its declaration in October 2024, per WHO AFRO. Treating water at the household level is one of the few interventions a family can carry out the same day, before a tanker or a chlorinated tapstand reaches them.

Why does a chlorine tablet alone fail on flood water?

Chlorine is excellent against bacteria and viruses, but it has two weaknesses that flood water exposes directly. First, suspended particles physically shield pathogens from the disinfectant and soak up chlorine as demand, so a dose that works on clear water is consumed before it can act. Second, chlorine is weak against certain protozoan cysts. The standard household guidance reflects the turbidity problem: roughly 2 mg/L of chlorine for water below 10 NTU and around 4 mg/L for water above 10 NTU, per the CDC guidance on making water safe in an emergency. Flood water sits far above that threshold, and chasing it with more chlorine treats the symptom while leaving the particles and the chlorine-resistant parasites in place.

The manufacturer instructions for chlorine tablets say the same thing in plainer terms: filter cloudy water through a clean cloth before dosing, because a single Aquatabs 67mg tablet is designed to treat 8 to 10 litres of clear water with a 30-minute contact time, per the CDC and Medentech instruction sheet. A cloth removes the worst of the grit, but it does not clarify genuinely muddy floodwater, and it does nothing about Giardia or Cryptosporidium. When the water stays brown after filtering, the tablet is the wrong tool, and pushing it onto turbid water is the single most common treatment error in a flood response.

When does P&G Purifier of Water beat chlorination alone?

Use P&G Purifier of Water whenever the source is turbid, muddy, or heavily contaminated, which is the normal picture in a flood. The sachet was developed with the CDC and treats 10 litres through coagulation, flocculation, and disinfection in about 30 minutes, removing the suspended solids along with the Giardia and Cryptosporidium that survive ordinary chlorination, per the Center for Safe Drinking Water. It produces visibly clear water from a starting point a chlorine tablet cannot handle, and it disinfects in the same step, so the household ends up with water that is both clear and chlorinated.

That is the whole argument for floods. Chlorination alone fights the water it can see and loses to the particles it cannot. The flocculant pulls the solids out first, which removes both the chlorine demand and the cysts hiding behind the silt, then disinfects what remains. For a family drawing from a silty river or a runoff pond, this is the difference between water that looks treated and water that is safe to drink.

The trade-off is honest: P&G takes more steps and more briefing than a tablet. The user stirs the sachet into the water, waits for the floc to form and settle, pours the water through a clean cloth to catch the floc, then waits out the disinfection time. That is more demanding than dropping in a tablet, so for genuinely clear sources, such as a protected borehole or cleanly collected rainwater, a chlorine tablet remains the faster, lighter, simpler choice. The rule is not product loyalty; it is matching the product to the water. Cloudy after a cloth filter means P&G; clear means a tablet will do.

How does a household actually treat flood water, step by step?

The sequence is simple and worth briefing exactly once, clearly, at distribution:

1. Settle first if you can. Let the worst of the mud settle in the collection container before you start, which reduces the load the sachet has to handle.

2. Add the sachet to a known volume. One P&G sachet treats 10 litres, so dose to the container size and stir for the full mixing time so the coagulant disperses.

3. Let the floc form and settle. The particles clump and drop to the bottom; do not rush this stage.

4. Filter the floc out through a clean cloth into a second clean container, leaving the settled sediment behind.

5. Wait out the disinfection time before drinking, roughly 30 minutes in total for the full process.

6. Store it safely. Keep treated water in a covered, narrow-necked container and use a clean cup, so you do not re-contaminate by dipping dirty hands in. Sphere guidance is at least two clean 10 to 20 litre covered containers per household for exactly this reason, per the Sphere WASH standards.

Storage is not an afterthought. In South Sudan refugee camps, 40 to 58% of households drawing from chlorinated tapstands had no detectable residual chlorine in their stored water, and standard doses could not hold 0.2 mg/L of free chlorine 24 hours after distribution, per the Bulletin of the World Health Organization. Good treatment is undone by a dirty cup and an open bucket, so the container and the handling matter as much as the sachet.

What should an agency pre-position before the rains?

Pre-position both routes, matched to the water sources in the area, not a single product. A flood response that carries only chlorine tablets will be stuck the moment the source water turns to mud, and a response that carries only flocculant overspends on the clear sources where a tablet would do. The practical stock is P&G sachets for the turbid floodwater that defines the season, chlorine tablets for the protected and rainwater sources, and clean covered storage containers so the treated water survives to the cup. Sourcing all of it from one authorised in-country distributor means you can shift the mix as the rains change the water without re-tendering, and the full SLS WASH product range covers both treatment routes alongside the storage and testing supplies that complete the chain.

Frequently asked questions

How do I treat flood water for drinking at home?

Use a coagulation-flocculation-disinfection product such as P&G Purifier of Water, which treats 10 litres by settling out the suspended solids and then disinfecting, removing the Giardia and Cryptosporidium that resist chlorine alone, per the Center for Safe Drinking Water.

Can I just use chlorine tablets on muddy flood water?

Not on their own; particles shield pathogens and consume the chlorine, which is why standard guidance calls for far higher chlorine on turbid water, roughly 4 mg/L above 10 NTU versus 2 mg/L below it, per the CDC guidance on making water safe in an emergency. For genuinely muddy water, use P&G Purifier of Water instead.

Does flood water carry parasites that chlorine misses?

Yes; Giardia and Cryptosporidium resist ordinary chlorination, and P&G Purifier of Water removes them along with the suspended solids, per the Center for Safe Drinking Water.

Why is flood water so likely to cause disease?

Floods push sanitation waste into drinking-water sources; contaminated drinking water causes around 505,000 diarrhoeal deaths a year, and about 88% of diarrhoeal deaths in children under five are attributable to unsafe water, sanitation, and hygiene, per the WHO drinking-water fact sheet and CDC Global WASH.

How should I store water after treating it?

In a covered, narrow-necked container with a clean cup, at least two 10 to 20 litre containers per household, per the Sphere WASH standards, because stored water often loses its chlorine residual within a day.

Specialized Logistics Solutions is an in-country distributor based in Juba, an authorised distributor for Aquatabs (Medentech/Kersia), P&G Purifier of Water, and Oxfam tanks (Butyl Products), and a UNGM-registered vendor (No. 380716). During the 2024-2025 cholera response we distributed 3.28 million P&G Purifier of Water sachets to 27,344 households across South Sudan, so we can put the right treatment for turbid floodwater where it is needed across South Sudan. Request a quotation from SLS to pre-position P&G sachets and clean storage before the rains.