WaSH During Emergencies: Emergency Water Standards and Usage

30 September 2026 ·Wateroam

When disaster strikes, basic human necessities must be secured to prevent further loss of life.

Among these necessities is water. Without clean water, the risks of dehydration and infection from water-related diseases increases. To mitigate these risks and save lives, first responders and humanitarian organisations globally carry out water, sanitation and hygiene (WaSH) programmes.

This article is to serve as an overview of Water, Sanitation and Hygiene(WaSH) fundamentals, water usage requirements, and standards and emergency water treatment during emergencies while providing links to relevant guidebooks, standards and policies that you can access below.

This overview summarises and draws heavily from Unicef’s Emergency Technical Guidelines (Sudan 2017). (1)

Emergency WASH Fundamentals

According to the UNICEF endorsed Sphere Handbook (2): the main objective of WaSH programmes during disasters is to reduce the transmission of faecal-oral diseases and exposure to disease-bearing vectors through the promotion of:

Good hygiene practices
The provision of safe drinking water
The reduction of environmental health risks
The conditions that allow people to live with good health, dignity, comfort, and security

Sphere(3) is a movement that was started in 1997 by “a group of humanitarian professionals aiming to improve the quality of humanitarian work during disaster response.”

The Sphere handbook is their flagship publication which global bodies like Unicef and UNHCR have recognised.

The use of WaSH to prevent the spread of disease and dehydration is summarised in the diagram below:

To summarise the diagram, to prevent the spread of disease from faecal matter, different WaSH barriers are used:

Clean water sources and proper water distribution systems (W in the diagram)
Sanitation (S in the diagram): e.g. proper toilets, drainage and waste management, etc.
Hygiene practices (H for hygiene in the diagram): e.g. washing and storing food and washing hands

These barriers prevent the spread of infection from the following vectors or transmission methods:

Fluids
Fingers
Flies
Fields
Floods

All these practices are targeted at reducing the spread of the following WaSH related diseases:

Water-borne diseases:
- Caused by the ingestion of water contaminated by human or animal faeces containing pathogens.
Water-washed diseases:
- Caused by inadequate use of water for domestic and personal hygiene. Often related to a lack of water.
Water-based diseases:
- Infections caused by parasites usually found in aquatic organisms, for example schistosomiasis.
Water-related diseases:
- Insect vectors, breeding or living in or around water. The main cause of malaria.
Diarrhoea, acute respiratory infection (pneumonia), and malaria:
- Three big killers of children under five can be found here.

This article focuses more on water standards, usage and treatment via filtration during emergencies.

If you’d like to find out more about sanitation (e.g. toilet management) and hygiene promotion activities, we recommend the following resources:

Sphere Handbook (Latest edition as of time of writing is 2018)
- Sphere standards have been adopted by different global agencies when it comes to humanitarian aid
Unicef’s Water, Sanitation and Hygiene Sector Emergency Technical Guidelines (Sudan)
- This guide provides an overview of all the WaSH activities and standards, with references to the Sphere Handbook
Humanitarian Response - Emergency WASH Response Minimum Standard - revised 4 April 2020
- This short document covers all the minimum standards for water supply, sanitation, hygiene promotion, solid waste management, WASH in disease outbreaks and healthcare settings
WHO and Public Health England’s Fact Sheet on Health Emergency and Disaster Risk Management - WATER, SANITATION AND HYGIENE
- 2-page fact sheet on WASH’s key points

Emergency Water Supply

Water Supply Standards

Being the ‘W’ in WaSH, the provision of clean drinking water reduces infection from water-borne diseases that occur when people drink unclean and unsafe water.

The Sphere handbook has 2 water supply standards:

2.1 - Access and water quantity
2.2 - Water quality

These are explored in detail below:

References:

*CFU (4) stands for Colony Forming Units - a measure of the amount of living microorganisms in a liquid

**NTU(5) means Nephelometric Turbidity Unit - a measure of the opaqueness of a fluid due to the presence of suspended solids

*** FRC(6) means Free Residual Chlorine - the portion of the chlorine dose which forms a powerful disinfectant after the chlorine demand of the water has been used up. FRC remains in the water after the initial disinfection has occurred, but will decay with time.

Recommended Water Usage Amounts

During emergencies, emergency water supplies need to provide an adequate amount of water to the affected persons for drinking and other uses.

Below is the recommended amount of water per person for each household as well as the amounts needed for other usages:

For households

Reference: Sphere Handbook 2018 Page 107

For medical centres

For other uses

Reference: Sphere Handbook 2018 Appendix 3

How Water Filtration Helps During Emergencies

According to UNICEF, water quality is measured in terms of having a safe microbiological quality level, safe physical quality and safe chemical quality.

Water quality is defined in terms of “microbiological contamination, chemical and physical parameters.”

Microbiological contamination
- In the early phases of emergencies, microbiological contamination leads to diseases like diarrhoea and is the most important to eliminate via disinfection.
Physical (turbidity)
- Turbidity refers to physically visible particles in the water. Highly turbid water will prevent effective disinfection.
Chemical
- Some chemical parameters are important for long-term health but are not considered in first phase emergencies unless an assessment suggests these would be a high risk.

Water filtration helps in terms of the microbiological and physical quality aspects of water.

Water filters remove a lot of the physical solids found in water, which can interfere with the cleanliness of the water at later stages of water treatment if left unfiltered.

As for the microbiological quality, water filters with small enough pores are able to remove a large quantity of microorganisms such as bacteria, helminths, protozoa, viruses and cysts by up to 99.99% or more.

Filtration’s Role in Reducing Turbidity

Turbidity refers to the physical quality of the water. Turbidity, along with the other two water quality measures has to be taken into consideration when setting up the emergency water supply system. Below is what a typical bulk water treatment setup looks like that takes into account turbidity along with the water supply’s microbiological and chemical quality:

Stages:

Water abstraction and pumping
Raw water storage
Pre-treatment (such as roughing filtration)
Coagulation/Flocculation/Sedimentation or Sand filtration
Chlorination
Storage
Distribution

In emergency situations, ensuring that the microbiological quality of the water is safe is vital to preventing water-borne diseases from spreading, and is controlled by disinfection and chlorination.

High turbidity affects the disinfection (chlorination) process due to the sediments floating in the water. Filtration and sedimentation are used to reduce the turbidity to 5 NTU as a pre-treatment to chlorination.

There are multiple types of filtration methods:

Bulk Filtration Methods:

Pressurised Sand Filters
- Pressurised sand filtration is one of the options used for emergencies. These are combined with coagulation and flocculation processes to increase the sediment size and make filtration easier, along with activated carbon and chlorination.
- These can be rapidly deployed via mobile water treatment units, but have high capital and operation costs and require skilled operators, but are able to output between 3 to 5000 litres per hour.
Slow Sand Filters
- These are more applicable in longer-term emergencies, as they make use of gravity to filter large quantities of water through sand without the help of pressure mentioned above to remove pathogen load and turbidity.
- Their setup requires a raw water tank, floating outlet, and roughing filter before hooking it up to the slow sand filter.
Membrane filters
- In membrane filtration, the water is passed through the membrane at low pressure.
- These membranes have a pore size of around 10^-7m which helps to prevent the passing of bacteria, helminths, protozoa, and cysts by up to 99.99% or more, and viruses are also significantly reduced.
- Turbidity will be reduced to about 0.1 NTU.
Simple Household Filtration technique: Cotton Cloth
- Straining water through a piece of fine, cotton cloth is able to remove some of the suspended solids and insect larvae from the water.
- This had some results in Bangladesh according to Unicef (Page 99): “In Bangladesh, folding a cotton cloth in four and straining water through that, reduced the cholera bacilli by 90% and in the villages where this was promoted, cholera rates reduced by 50% (New York Times, 2011)

Using filtration in conjunction with chlorination can be highly effective in reducing the presence of microbes like protozoa and helminth eggs that chlorination alone is less effective in killing.

How Wateroam Helps Out

Over the years, Wateroam has been distributing its filters to locations that require disaster relief to deal with the turbidity of their emergency water supplies. Below are examples of how we’ve helped in Indonesia and the Philippines.

Lombok Earthquake Relief

2000 people reached
BGR International sent their Disaster Assessment Team to support the relief efforts after the devastating earthquakes in Lombok. Wateroam was able to provide clean water to the earthquake victims in collaboration with BGR International with four ROAMfilter™ Plus systems.

As existing water sources and transport routes are disrupted and only contaminated water is available, our portable filtration systems were able to be quickly distributed and set up to support the relief effort. With the four units deployed, a total of 2000 people can be supported with 4800 litres of clean water produced daily. Due to the success of the operation, BGR International will continue to deploy another 38 systems in the following two months.

You can read more about our efforts in Indonesia here.

Links to Helpful Resources:

Links to Helpful Resources

All the information provided in this overview only scratches the surface of what goes on during WaSH programmes during emergency situations. We’ve collected resources below for your perusal in other WaSH areas which we hope you’ll find useful:

Sphere Handbook (Latest edition as of time of writing is 2018)
- Sphere standards have been adopted by different global agencies when it comes to humanitarian aid
Unicef’s Water, Sanitation and Hygiene Sector Emergency Technical Guidelines (Sudan)
- This guide provides an overview of all the WaSH activities and standards, with references to the Sphere Handbook
How to implement a successful safe water project (Indonesia) | Wateroam Webinar
- This webinar covers multiple steps for managing sustainable water projects in Indonesia from identifying water sources, filter maintenance to empowering and communicating with the community
Humanitarian Response - Emergency WASH Response Minimum Standard - revised 4 April 2020
- This short document covers all the minimum standards for water supply, sanitation, hygiene promotion, solid waste management, WASH in disease outbreaks and healthcare settings
WHO and Public Health England’s Fact Sheet on Health Emergency and Disaster Risk Management - WATER, SANITATION AND HYGIENE
- 2-page fact sheet on WASH’s key points
Centre for Disease Control and Prevention’s collection of webpages, fact sheets, posters, toolkits, and other relevant information to help WaSH professionals, first responders and more.
Institute of Migration’s list of resources for Wash Technical Operations
Emergency Wash Knowledge Portal
- An online library that splits the three WaSH pillars into different components for WaSH professionals to use.

We hope that you’ve found this resource helpful and insightful.

Wateroam is always ready to support WaSH programmes worldwide with our water filters and aim to make a difference whether it’s for disaster relief or rural development initiatives.

To find out more about our work and our products, reach out to us below:

(1) UNICEF - Water, sanitation and hygiene sector emergency technical guidelines for Sudan
(2) The Handbook editions and languages | Sphere Standards
(3) About Sphere
(4) Colony Forming Units - CFU in water bearing systems.
(5) Nephelometric Turbidity Unit - an overview | ScienceDirect Topics
(6) Chlorination for Water Treatment in Humanitarian Responses | Oxfam WASH Resources

← Back to blog