Ensuring Safe Water Supply and Sanitation During Disasters

When disaster strikes, the immediate focus often falls on rescue operations and emergency shelter. However, ensuring access to safe water and proper sanitation is equally critical for survival. Contaminated water and poor sanitation can quickly transform a disaster into a full-blown public health catastrophe, with outbreaks of cholera, typhoid, and other waterborne diseases claiming more lives than the initial event itself. Understanding the minimum standards for water supply and sanitation during emergencies is essential for humanitarian responders, local authorities, and affected communities alike.

Why water and sanitation matter in disaster response 🔗

People affected by disasters face significantly increased vulnerability to illness and death from disease, much of which stems from inadequate sanitation, insufficient water supplies, and the inability to maintain basic hygiene. The primary objective of Water, Sanitation and Hygiene (WASH) programmes during emergencies is to reduce the transmission of faeco-oral diseases and limit exposure to disease-bearing vectors. This is achieved through promoting good hygiene practices, providing safe drinking water, and reducing environmental health risks.

Simply providing water and sanitation facilities will not automatically ensure their optimal use or achieve the desired public health impact. Disaster-affected populations need the necessary information, knowledge, and understanding to prevent water and sanitation-related diseases. They must also be involved in the design and maintenance of these facilities to ensure sustainability and cultural appropriateness.

Water supply standards 🔗

Water is essential for life, and in extreme disaster situations, access to clean water for meeting basic needs becomes critically important. Poor hygiene due to insufficient water, or the consumption of contaminated water, is frequently the primary cause of infection spread in disaster settings.

Quantity requirements 🔗

According to established humanitarian standards, a minimum of 15 litres per person per day should be provided as soon as possible during emergencies. However, in the immediate post-impact period when resources are severely constrained, it may be necessary to temporarily limit treated water to a survival minimum of 7.5 litres per day per person. This survival quantity covers only drinking and basic food preparation needs.

The total daily water requirement breaks down approximately as follows: 2.5 to 3 litres for drinking (varying with climate and individual physiology), 2 to 6 litres for basic hygiene practices, and 3 to 6 litres for basic cooking needs. When circumstances allow, this amount should increase to 20 litres per person per day to accommodate laundry, bathing, and more thorough hygiene practices.

Access and distance standards 🔗

The location of public water points must be planned sufficiently close to households to enable use of the minimum water requirement. The maximum distance from any household to the nearest water point should be 500 metres, and the maximum queuing time at a water source should not exceed 30 minutes. When selecting water sources, groundwater or gravity-flow supplies from springs are preferable as they require less treatment and no pumping.

Accessibility standards also specify approximate flow rates: 250 people per tap (based on a flow of 7.5 litres per minute), 500 people per hand pump (17 litres per minute), and 400 people per single-user open well (12.5 litres per minute). All community members must have equitable access regardless of gender, ethnicity, or physical ability.

Water quality and contamination prevention 🔗

During emergencies, it should be assumed that all water is at risk of contamination, including piped supplies. The quality of urban drinking-water supplies is particularly vulnerable following structurally damaging disasters. Water treatment works may be damaged, causing untreated or partially treated water to enter the distribution system, while broken sewers and water pipes can cause cross-contamination.

Floods present special contamination risks, as they may contaminate wells, boreholes, and surface water sources with faecal matter washed from the ground surface or from overflowing latrines and sewers. Where there is evidence of faecal contamination, it may be necessary to modify treatment of existing sources or temporarily use alternative drinking-water sources. Free chlorine residual in disinfected water should be maintained at 0.2 to 0.5 mg per litre, increasing to at least 1 mg per litre during diarrhoeal disease outbreaks.

Water treatment options include aeration to remove volatile substances, sedimentation, filtration using membrane, sand or ceramic filters, and disinfection through boiling, solar methods, or chemical treatment with chlorine. When centralised treatment systems are unavailable, point-of-use water treatment at the household level becomes a viable alternative.

Sanitation facilities 🔗

Safe excreta disposal creates the first barrier to excreta-related disease and represents a major priority in most disaster events. It should be addressed with as much speed and effort as providing a safe water supply.

Toilet ratios and accessibility 🔗

The fundamental standard for sanitation is maintaining the living environment free from human faecal contamination. After a disaster, demarcating and cordoning off defecation areas, followed by building communal toilets, should be completed as quickly as possible. The key indicator is a maximum of 20 people per toilet, with use arranged by household or segregated by sex.

Disaster-affected populations need adequate, appropriate, and acceptable toilet facilities sufficiently close to their dwellings to allow rapid, safe, and secure access at all times, day and night. Toilets must have safe access and provide privacy in line with cultural norms. The distance from dwellings should be no more than 50 metres. Special considerations may be needed for children, older people, and persons with disabilities, potentially requiring specially designed facilities.

Design and placement requirements 🔗

All excreta containment measures, including trench latrines, pit latrines, and soak-away pits, should be at least 30 metres away from any groundwater source. Pits should be at least 1.5 metres above the groundwater table, with increased distances required for fissured rocks and limestone formations. In flooded environments, toilets or septic tanks must be built in elevated areas to prevent spillage and contamination.

The type of sanitation facility adopted depends on several factors: the phase of the disaster response, user preferences, existing infrastructure, local soil characteristics, construction materials, and water availability. For the initial days, demarcated defecation areas may be necessary. Trench latrines are suitable for use up to two months, while simple pit latrines, ventilated improved pit (VIP) latrines, and ecological sanitation systems are appropriate for longer-term situations.

Public toilets at markets, distribution points, and health centres should be provided at a ratio of 3:1 (women to men), with urinals provided where possible. Toilets must include adequate water supply and cleansing materials, containers for disposal of menstrual hygiene materials, and hand washing facilities with soap.

Hygiene promotion and solid waste management 🔗

Hygiene promotion is a vital component of any successful WASH intervention. It enables disaster-affected people to learn how to prevent and mitigate water, sanitation, and hygiene-related diseases through a planned, systematic approach.

Key hygiene behaviours 🔗

The most critical hygiene messages focus on handwashing with soap at key moments: after defecation, after cleaning a child’s bottom, and before eating or preparing food. In camp settings, there should be two hygiene promoters per 1,000 members of the affected population to ensure adequate outreach.

A basic minimum hygiene items pack should include water containers (two 10-20 litre capacity containers per household, one for transportation and one for storage), bathing soap (250g per person per month), laundry soap (200g per person per month), and acceptable menstrual hygiene materials for women and girls. Information should be disseminated through multiple channels, targeting different at-risk groups including those who are illiterate or have communication difficulties.

Solid waste management 🔗

Inadequate solid waste management creates public health risks through the breeding of flies and rodents and pollution of water sources. According to humanitarian standards, all households should have easy access to refuse containers, with at least one 100-litre container available per 10 households. These containers should be emptied at least twice weekly, though waste should ideally be removed from living environments daily.

Communal refuse pits should be located no more than 100 metres from households. If waste is buried on-site, it should be covered daily with a thin layer of soil to prevent attracting flies and rodents. Medical waste requires special attention and must be isolated and disposed of separately in properly engineered pits or incinerators at health facilities.

Vector control 🔗

Vector-borne diseases represent a major health risk following disasters. Mosquitoes transmit malaria, dengue, and yellow fever; flies transmit diarrhoeal diseases; fleas can transmit plague and typhus; and rodents spread leptospirosis and other infections. Effective vector control requires reducing breeding sites through proper drainage, eliminating standing water, maintaining safe water supplies, and ensuring proper excreta and solid waste disposal.

Individual protection measures include insecticide-treated bed nets (effective against mosquitoes, lice, fleas, and bedbugs), long-sleeved clothing, household fumigants, and regular washing of clothes and bedding. Camp sites should ideally be located 1-2 kilometres upwind from large mosquito breeding sites such as swamps or lakes.

The path to recovery 🔗

Meeting minimum standards for water supply and sanitation during disasters is not merely a technical exercise but a fundamental expression of human dignity. These standards, developed through decades of humanitarian experience and refined through initiatives like the Sphere Project, provide a benchmark for ensuring that disaster-affected populations can survive and recover with their health and dignity intact. As climate change increases the frequency and intensity of disasters worldwide, understanding and implementing these standards becomes ever more essential.

What do you think? How can communities better prepare their water and sanitation infrastructure to withstand disasters? What role should local knowledge play in designing culturally appropriate sanitation solutions during emergencies?

References

1. https://www.who.int/teams/environment-climate-change-and-health/water-sanitation-and-health/environmental-health-in-emergencies/humanitarian-emergencies
2. https://spherestandards.org/handbook/
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC4910130/
4. https://emergency.unhcr.org/emergency-assistance/water-hygiene-and-energy/wash-camps
5. https://www.oxfamwash.org/domestic-and-refugee-camp-waste-management/