Calculating Point-of-Use Water Treatment Needs for Cholera Response in South Sudan: A Field Planning Guide for WASH Teams

South Sudan's 2026 rainy season started with an active cholera outbreak already spread across 16 counties, 535 tonnes of WASH supplies delayed in transit, and above-normal rainfall forecast through October for Jonglei, Unity, and Upper Nile — the three states most vulnerable to the compound flooding and disease cycles that have defined the last two rainy seasons. For a WASH officer or NGO procurement manager trying to size a point-of-use water treatment response right now, the gap between what the Sphere Handbook recommends and what field teams can actually source and deliver in a flood-disrupted environment is where outbreaks get traction.

This guide walks through the calculation logic for household-level water treatment quantities, the choice between P&G Purifier of Water sachets and Aquatabs chlorine tablets for different population profiles, the Sphere thresholds that govern minimum coverage, and how to structure procurement when supply chains are under stress.

Quick answers for field teams:

• Each P&G Purifier of Water sachet treats 10 litres of turbid flood water — plan 2 sachets per person per day at Sphere's 20 L target, plus 30% buffer.

• Aquatabs 67mg are NOT effective in flood-turbid water above 1 NTU; use P&G sachets for surface or post-flood open-well sources.

• WHO cholera-response FRC target: 0.5 mg/L minimum at point of use — higher than the standard Sphere emergency threshold of 0.2–0.5 mg/L.

• As of April 2026, 535 tonnes of WASH supplies serving 575,140 people are delayed; order before June to pre-position ahead of flood-peak access collapse.

• Specialized Logistics Solutions (SLS) holds exclusive South Sudan distribution rights for P&G Purifier of Water and is an authorised Aquatabs distributor — Juba and Kampala stock available now.

Why Point-of-Use Treatment Matters More When Infrastructure Fails

The primary transmission pathway for Vibrio cholerae is faecally contaminated drinking water. When floodwaters inundate hand pump aprons, open wells, and shallow boreholes, even households that normally access treated water fall back on whatever source is accessible — rivers, flooded depressions, or trucked water from unverified sources. In these conditions, centralised chlorination at the source is insufficient on its own because the distribution network breaks down at the same time as contamination peaks.

OCHA's April 2026 South Sudan Humanitarian Update documented this dynamic directly: as of 10 April, 102,105 cholera cases and 1,662 deaths had been reported, with a case fatality rate above the 1% emergency threshold set by WHO. The same update noted that 535 tonnes of WASH and SNFI supplies — enough to serve 575,140 people — had been delayed, and that destruction and looting of hand pumps, latrines, and water storage had reduced services at the household level across eight states. Point-of-use treatment is not a secondary backup in this context. It is the intervention that reaches households when supply chains to centralised infrastructure have broken. See the OCHA South Sudan April 2026 update for full figures.

The Sphere Handbook sets a minimum of 15 litres per person per day for survival needs, with a target of 20 litres per person per day for a basic dignified standard. Free residual chlorine (FRC) at the point of use should be between 0.2 and 0.5 mg/L under normal emergency conditions. During active cholera transmission, WHO guidance raises the target FRC to 1.0 mg/L at the source and recommends maintaining 0.5 mg/L or above at the point of use. Any WASH programme planning for South Sudan's 2026 rainy season should be using the cholera-response chlorination thresholds — not the standard emergency thresholds — because the outbreak is already active.

P&G Purifier of Water: How It Works and When to Use It

Each P&G Purifier of Water sachet treats exactly 10 litres of water using a two-stage process: ferric sulfate coagulates and settles suspended solids and particulates, and calcium hypochlorite disinfects. The WHO International Scheme for Evaluating Household Water Treatment Technologies assigns P&G Purifier of Water a 2-star Comprehensive Protection classification, indicating greater than 4-log (99.99%) reduction in bacteria and viruses, including the Vibrio cholerae bacterium responsible for cholera. Treatment takes 30 minutes and requires only a clean cloth for filtering the settled floc.

The key operational advantage of P&G sachets is performance in turbid water. During flood conditions in South Sudan, surface water turbidity routinely exceeds 100 NTU — high enough to render chlorine tablet products like Aquatabs ineffective, because chlorine demand rises with turbidity and residual levels drop below protective thresholds. The coagulation step in P&G sachets reduces turbidity before disinfection, which means the product maintains protective efficacy even in the heavily silted, flood-affected water sources that dominate the rainy season in Jonglei and Unity states.

P&G sachets are most effective for household distribution to families using river water, open wells post-flood, and any source where turbidity is variable or elevated. They work in standard 10-litre containers — a common household vessel across South Sudan — which simplifies training and reduces dosing errors.

For procurement planning: Specialized Logistics Solutions (SLS) holds exclusive distribution rights for P&G Purifier of Water in South Sudan and maintains pre-positioned stock in Juba for immediate dispatch. Full product specifications and minimum order quantities are available via the WASH products page.

Aquatabs 67mg: When and How to Deploy Them

Aquatabs 67mg effervescent tablets contain sodium dichloroisocyanurate (NaDCC), which releases free chlorine on dissolution. Each tablet treats 20 litres of moderately turbid water (less than 1 NTU after settling) to a residual of 0.5–1.0 mg/L. Aquatabs are faster to deploy than P&G sachets — no waiting for coagulation and settling — making them suited to populations drawing from borehole or hand-pump sources where turbidity is consistently low, distribution points with pre-sedimented water, and rapid NFI kit distributions where speed of deployment matters.

The Global WASH Cluster guidance on household water treatment tablet selection recommends combining products across a distribution area based on water source type. In practice, for a South Sudan flood response: use P&G sachets for households drawing from surface water or post-flood open wells, and Aquatabs for households with access to rehabilitated boreholes or UNICEF-supported emergency water points. Mixing the two products within a single household NFI kit is also common practice — the P&G sachet addresses acute turbid-water episodes and the Aquatabs maintain daily treatment once turbidity subsides.

Specialized Logistics Solutions (SLS) is an authorised distributor of Aquatabs 67mg and carries stock in Juba and Kampala. See the WASH products page for current availability and UNGM-compliant pricing.

Quantity Calculations: Sizing Your Procurement

Field teams frequently undersize POU treatment procurement because they calculate only against the target population, not against the likely replacement rate from loss, spoilage, or distribution failures in flood conditions. A conservative planning factor of 1.3x (30% buffer) is standard WASH Cluster practice for emergency distributions in flood-affected areas. Apply this to all calculations below.

P&G Purifier of Water sachet calculation:

• Sphere target: 20 litres/person/day

• Each sachet: 10 litres treated

• Sachets per person per day: 2 sachets

• For 1,000 people for 30 days: 2 × 1,000 × 30 = 60,000 sachets

• With 1.3x buffer: 78,000 sachets

Aquatabs 67mg calculation:

• Sphere target: 20 litres/person/day

• Each tablet (67mg): treats 20 litres

• Tablets per person per day: 1 tablet

• For 1,000 people for 30 days: 1 × 1,000 × 30 = 30,000 tablets

• With 1.3x buffer: 39,000 tablets

These calculations assume full Sphere coverage. In most South Sudan flood response scenarios, the realistic distribution coverage rate in the first two weeks is 40–60% of the target population due to access constraints, meaning your procurement quantity should target 100% coverage to achieve 50% actual distribution. Plan for the gap, not the ideal.

Procurement managers should also build in a lead time buffer of at least 21 days for in-country delivery, even from pre-positioned Juba stock, given road access disruptions during the June–October flood peak. The April 2026 OCHA update confirms that 535 tonnes of WASH supplies have already been delayed this cycle — pre-ordering before the flood peak is the only reliable mitigation strategy.

Integrating POU Treatment Into a Cholera Response Plan

Point-of-use treatment sits within a response chain, not as a standalone intervention. WHO and the Sphere Handbook both emphasise that household water treatment must be accompanied by safe storage (covered containers), hygiene promotion, and sanitation improvements to break the cholera transmission cycle fully. A sachet distribution without a hygiene promotion session typically achieves lower sustained uptake than a distribution paired with a 20-minute community demonstration.

The evidence base for this is clear. A PLOS ONE field study of household water treatment uptake in cholera-endemic settings found that distribution alone increased treatment rates by 12%, while distribution combined with a practical demonstration increased sustained uptake by 34% at 30 days. For South Sudan, where the Ministry of Health's WASH cholera response is ongoing across Mayom, Panyijiar, Awerial, Renk, and 12 other counties as of April 2026, the implication is that sachet procurement planning should include a line for hygiene promoter support — typically one hygiene promoter per 250 households in IDP settings per Sphere guidance.

For rapid-onset flood response where the population is mobile and access is constrained, the practical minimum is a pictorial instruction card packed with each monthly household kit. P&G sachets include a QR-linked instruction format suited to this purpose. For a full list of available distribution materials and minimum pack configurations, contact the team at sales@maji-safi.org.

What This Means for Your Programme

South Sudan entered the 2026 rainy season with cholera already active in 16 counties, the worst WASH supply disruption in three years, and above-normal rainfall forecast through October. Point-of-use treatment — P&G Purifier of Water for turbid flood-source water, Aquatabs for treated borehole sources — is the intervention that closes the gap between centralised chlorination and actual household-level protection.

Procurement teams that wait for flood peak to place orders will face the same delays OCHA is documenting now. The window to pre-position before the June–August peak is open, but narrow.

For related products — pumps for water point establishment, tanks for safe storage, and shelter for distribution hubs — see the pumps and equipment page and warehouses and shelters page. Specialized Logistics Solutions (SLS) holds pre-positioned stock of P&G Purifier of Water sachets and Aquatabs 67mg in Juba and Kampala, available for rapid dispatch. Contact the team at sales@maji-safi.org.

Frequently Asked Questions

How many P&G Purifier of Water sachets do I need per household per month?

A standard South Sudan household of five people using 20 litres per person per day requires 10 sachets per day (2 sachets × 5 people, each sachet treating 10 L). Over a 30-day month, that is 300 sachets per household. With a 30% loss and spoilage buffer, order at least 390 sachets per household per month for reliable coverage.

Can I use Aquatabs in flood-turbid water in South Sudan?

No. Aquatabs 67mg are designed for water with turbidity below 1 NTU after settling. During flood conditions in South Sudan, surface water turbidity routinely exceeds 100 NTU. In these conditions, use P&G Purifier of Water sachets, which include a coagulation step that reduces turbidity before chlorine disinfection. Applying Aquatabs to highly turbid water will deplete the chlorine in the tablet without achieving protective free residual levels.

What is the correct free residual chlorine target for cholera response?

The Sphere Handbook sets a standard emergency target of 0.2–0.5 mg/L FRC at the point of use. During active cholera transmission, WHO raises this to a target of 0.5 mg/L or above at the point of use, with 1.0 mg/L at the source. South Sudan's 2026 outbreak context requires the elevated WHO cholera-response threshold, not the standard Sphere minimum.

How far in advance should I order POU treatment supplies for South Sudan?

Allow a minimum of 21 days for in-country delivery from pre-positioned Juba stock under normal road access conditions. During June–October flood peak, road access to many priority counties — Jonglei, Unity, Upper Nile — is severely disrupted and delivery timelines extend. The April 2026 OCHA update documented 535 tonnes of WASH supplies delayed across eight states. Order before the flood peak — ideally by the end of May or early June at the latest — to ensure pre-positioning before access collapses.

Does Specialized Logistics Solutions supply to NGOs as well as UN agencies?

Yes. Specialized Logistics Solutions (SLS) is UNGM-registered (Vendor No. 380716) and supplies to UN agencies, international NGOs, and national NGOs. SLS holds exclusive distribution rights for P&G Purifier of Water in South Sudan and is an authorised distributor of Aquatabs 67mg. Contact sales@maji-safi.org for quotations, minimum order quantities, and current stock availability in Juba and Kampala.