Ebola Treatment Units: Pumps, Wastewater and Dewatering on a Contained Site

Tony Miller

3 days ago

7 min read

An Ebola treatment unit has to plan for 100 to 400 litres of water per person per day, and almost all of it leaves the site as liquid waste. The pumping job is therefore not clinical: it is moving, holding and draining water without letting any of it leave the fence uncontrolled.

How much wastewater does a treatment unit actually produce?

Plan on most of the water you bring in coming back out. UNICEF's WASH package guidance note for Ebola care and treatment centres (10 October 2014) estimates 100 to 400 litres per person per day for cleaning, laundry, chlorinated handwashing, footbaths, disinfection, drinking and oral rehydration solution. It also asks for at least two days of storage on site. That is the figure a pump planner should size against, and it is concentrated inside a fence.

Two things follow. First, every footbath, laundry point and shower needs somewhere to drain, and UNICEF's note specifically says to consider space and drainage to soak ways when siting laundries and showers. Second, the volume is the problem you can reduce. The same note advises separating grey water from black water to minimise the volume undergoing treatment. Anything that cuts the volume cuts the number of pump runs and the number of times a worker in full protective equipment has to touch a hose.

One caveat applies to everything below. The two documents I rely on for the sanitation detail date from 2014, from the West Africa response. The 2026 outbreak is Bundibugyo virus disease, and as of the WHO Emergency Committee statement of 28 August 2026, approximately 5,000 cases had been reported in the DRC as of 18 August, across 55 health zones in Ituri, North Kivu and South Kivu. Concentrations, holding times and waste routes on your site must follow your agency's current IPC and WASH protocol. Equipment does not replace that protocol.

What does WHO say about holding wastewater before it goes anywhere?

Hold it, and give time to do the work. WHO's Ebola key questions and answers on water, sanitation and hygiene says containing wastewater before secondary treatment allows natural die-off of the virus. It recommends, as a minimum for flush toilets, on-site septic tank treatment with later controlled removal. It also says there is no evidence to date of Ebola transmission via sewerage systems, and that sewered facilities should be risk-assessed to confirm the wastewater does not leak before it reaches a working treatment site.

For pit latrines, the same WHO document gives site rules that decide where your drainage can go: at least 1.5 metres between the pit bottom and the groundwater table, and latrines at least 30 metres horizontally from any groundwater source, including boreholes. Where the water table is high or space is short, it says to retain excreta in impermeable storage containers as long as is feasible, and it suggests two parallel tanks so one can fill while the other sits.

UNICEF's note adds figures for a simple treatment unit: a stabilisation pond with at least one hour of retention time and sludge tanks with about two months of capacity. WHO notes that waste stabilisation ponds work well on pathogens because retention of 20 days or more combines with sunlight and elevated pH.

My view is that this is where treatment sites go wrong on pumps. Teams buy one large pump for "the site" and plumb nothing around it. A contained site needs a layout first: grey water to a fenced soak-away or drain, black water to holding tanks, and a stormwater route that never meets either. Pumps are the fourth item, not the first.

Which water needs a pump, and which needs gravity?

Let gravity do the grey and black water if the ground allows, and keep pumps for the three jobs gravity cannot do.

Stormwater and flood protection. Rain falling on a fenced, partly covered site has to leave without crossing a contaminated zone. In flood-prone ground, a perimeter drain with a sump and a trash pump is the difference between a working unit and one that is closed because the low corner is under water. South Sudan's 2021 floods affected about 1.2 million people according to the World Bank.
Transfer between holding tanks. Moving settled grey water or tank overflow from one holding point to the next, or into a soak-away at the far side of the site, is a short, low-head job.
Raw water supply. Borehole or surface water has to reach the storage tanks that give you the two-day buffer. That is a submersible, solar or surface pump job, and it is the one area where power and fuel reliability decide uptime.

Pumping excreta is a different category. WHO says all workers handling excreta wear full PPE, and that for crews pumping out tanks or unloading pumper trucks, great care must be taken to avoid splashing. I will not tell you how to run a desludging operation on an Ebola site: that sits with your IPC and waste lead and with the agency's own protocol. What equipment planners can do is keep the risky operation small, scheduled and not improvised, by making sure the clean-water, stormwater and grey-water systems do not need an emergency visit from the same crew.

What pump suits a contained site?

A self-priming trash pump for dewatering and grey-water transfer, a submersible pump for water supply, and a spare of each. A trash pump earns its place because the water is never clean: leaves, mud, laundry lint and grit.

The Multiquip QP3TH 3-inch trash pump is rated by the manufacturer at up to 1,500 litres per minute (396 gpm), passes solids to 37 mm, reaches a maximum head of 95 ft and lifts from 7.6 m. For the grey-water and storm-drain duties above, the 3-inch is normally enough, and its lower weight matters when the person moving it is in full protective gear.

Selection rules I would apply on a contained site:

Self-priming and low maintenance. Every service call into a contaminated zone costs time and exposure. Pick a pump with a short list of wear parts and spares in Juba.
One engine type across the site. Mixed fuels mean mixed spares. If you can plan solar for the water supply side, do it, since a clean-water pump that stops because diesel did not arrive is the one failure that cannot wait.
Dedicate the pump to the zone. A pump and hose set used in a contaminated area stays in that area and is decontaminated per protocol before it leaves. Buy enough units that this is possible.
Spare delivery hose and a spare pump. Hoses split and pumps fail. Holding them in stock in Juba rather than ordering ex-works is the point of local supply.

SLS is an authorised distributor for Multiquip and Aussie Pumps, covering trash, submersible and borehole, solar and high-pressure pumps, supplied from stock in Juba. We do not hire pumps, and we do not supply PPE, medical equipment or chlorine solutions. The pump equipment range is the dewatering and water supply side of the site only.

Why not just chlorinate everything that goes down the drain?

Because WHO says it is often unnecessary for grey water and unhelpful for solids. WHO's Q&A states that 0.5% chlorine is sufficient to inactivate the virus in water relatively free of solids, defined as under 10 mg/l, so grey water from washing reusable PPE and surfaces, which is already chlorinated at that strength, does not need to be chlorinated again. It must still go to drains connected to a septic system, a sewer or a soak-away pit, and a soak-away should be fenced inside the facility grounds to prevent tampering and exposure on overflow.

For solids it goes the other way: WHO states chlorine is ineffective on media with large amounts of solid and dissolved organic matter, so adding it to fresh excreta gives limited benefit and may add splashing risk. UNICEF's 2014 note takes a more protective line for urine and vomit before a soak-away. The two documents are not identical, which is the strongest argument for following your own agency's current protocol and not mine.

The practical point for pump buyers is that all this chlorinated water has to be contained and moved, which is why drains, tanks and a small number of reliable pumps matter more than a long equipment list.

How do you keep a site from flooding on top of all this?

Design for the rainy season on day one, not after the first storm. The existing SLS guide to dewatering a flooded IDP site covers pump selection and deployment sequence for open camps. A treatment unit adds one rule to it: the stormwater route must be separate from the wastewater route, and no flood-pumping outlet should discharge on a path that crosses the site boundary near a water source. For the water side of the unit, our guide to WASH infrastructure for Ebola treatment units covers storage and chlorine supply planning, and the WASH products range lists the tanks and treatment products SLS supplies for it.

Frequently asked questions

How much water does an Ebola treatment unit need?

UNICEF's 2014 guidance note estimates 100 to 400 litres per person per day for cleaning, laundry, chlorinated handwashing, footbaths, disinfection, drinking and oral rehydration solution, with at least two days of storage on site.

Does grey water from an Ebola unit need to be chlorinated again?

Not if it was already chlorinated at 0.5% and is relatively free of solids (under 10 mg/l), according to WHO's water, sanitation and hygiene Q&A on Ebola. It must still go to a septic system, sewer or fenced soak-away pit.

How far should a latrine or soak-away be from a water source?

WHO says latrines should be at least 30 metres horizontally from any groundwater source and keep at least 1.5 metres between the pit bottom and the water table, in its Ebola WASH Q&A. It states more is needed in coarse sands, gravels and fissured formations.

What size trash pump suits site drainage?

For grey water and storm drainage a 3-inch trash pump is usually enough. The Multiquip QP3TH is rated at up to 1,500 litres per minute and solids to 37 mm.

Can SLS supply the pumps for an Ebola treatment unit?

SLS supplies Multiquip and Aussie Pumps from Juba stock, covering dewatering, water supply and flood protection. We do not supply PPE, medical equipment, vaccines or chlorine solutions, and our equipment does not replace IPC protocols.