Sanitation

1Latrines: the benchmarks

• In the acute phase: communal latrines with a maximum of 50 people per latrine, then aim for 20 people per latrine or family latrines as soon as possible.
• Less than 50 metres from dwellings, but at least 30 metres from any groundwater source, with the bottom of the pit at least 1.5 metres above the water table.
• Separate for men and women, with a lock on the inside, lighting at night and access for people with disabilities and children.
• A handwashing point with soap and water nearby, and solutions for menstrual hygiene management.

Women and girls must be consulted on location and design: badly placed latrines will not be used and expose people to violence.

2Faecal sludge and solid waste

• Plan from the outset for pit emptying (safe manual or mechanical), transport and treatment of sludge; a full pit with no solution becomes a health risk again.
• Solid waste: regular collection, drop-off points, refuse pits or controlled landfill; sorting where possible.
• Medical waste: a separate stream (segregation, sharps in safety boxes, incineration or appropriate burial).
• Protective equipment and vaccination (hepatitis B, tetanus) for sanitation workers.

3Drainage and vector control

Stagnant water around water points and shelters encourages mosquitoes (malaria, dengue) and disease. Provide drainage aprons around taps and showers, soakaway pits, and maintenance of channels.

Vector control combines environmental measures (drainage, waste), personal protection (insecticide-treated nets) and sometimes targeted treatments, in coordination with health.

4Choosing and sizing excreta disposal: criteria, phases and calculations

A sanitation option is not chosen from a catalogue. It depends on five sets of criteria that must be documented before the first latrine is drawn: soil and groundwater, available space, user practices, the foreseeable duration of the crisis, and the capacity to empty and treat faecal sludge. The Sphere benchmarks set the expected outcome (safe, dignified access that is actually used), not the technology.

Criteria to document

• Soil: ease of digging, stability of pit walls (unstable sand, expansive clay, outcropping rock), infiltration capacity. A simple percolation test (a 30 cm hole saturated with water, measuring how fast the level drops) helps identify soils where an infiltrating pit will work.
• Water table: depth in the dry season and in the rainy season, measured in existing wells or with hand-auger soundings. The bottom of the pit must remain at least 1.5 m above the highest level of the water table; in fissured or highly permeable soils (gravels, karstic limestone), this distance and the distance to water points must be increased.
• Distances: at least 30 m from any groundwater source, and no more than 50 m from dwellings.
• Practices: anal cleansing with water or dry materials, posture (squatting or sitting), taboos (sharing with other families or with in-laws, orientation), menstrual hygiene management, practices for children.
• Duration and downstream chain: a pit that fills up in three months with no emptying solution is not a solution.

Options by phase

Benchmarks for the number of toilets

Sizing a pit

Effective pit volume (m³) = number of users × sludge accumulation rate (m³ per person per year) × desired design life (years). A freeboard of about 0.5 m below the slab is added, which must never be filled.

The accumulation rate varies with the context. Commonly used benchmarks for a dry infiltrating pit: about 0.04 m³ per person per year where anal cleansing is done with water or degradable materials, about 0.06 m³ where non-degradable dry materials are used; more if users throw waste into the pit, which is common in the absence of solid waste management and menstrual hygiene solutions. In a sealed pit there is no infiltration: the entire volume of excreta, urine and cleansing water accumulates, which multiplies the emptying frequency.

A latrine that is compliant on paper may be unusable: a door that does not close, no lighting, odours, queues, an isolated location. The relevant indicator is not the number of latrines built, but the proportion of people who use them, by day and by night, and feel safe doing so.

5The faecal sludge management chain: emptying, transport, treatment and worker safety

Emergency sanitation was long thought of as "dig and build". In crises that drag on, faecal sludge becomes the main problem: full pits, overflows in the rainy season, illegal dumping into watercourses. Faecal sludge management should be thought of as a chain of five links, and one missing link makes the whole chain ineffective.

1. Containment: pit, sealed tank, container.
2. Emptying: safe manual emptying (hand pumps, long-handled tools) or mechanical emptying (vacuum truck, sludge motor pump).
3. Transport: tanker truck, trailer, closed drums, to the treatment site.
4. Treatment: stabilisation and pathogen reduction.
5. Disposal or reuse: controlled burial, land application after full treatment, compost.

Treatment methods usable in emergencies

Calculating emptying requirements

Monthly volume to be emptied (m³) = sum of the volumes of the pits that reach their emptying level during the month, estimated from fill-level readings. In the absence of data, start from a fill rate observed on a sample of pits during the first weeks (measuring the free height below the slab with a dipstick), then adjust. Number of truck trips = monthly volume ÷ (effective truck capacity × working days). Effective capacity is often 70 to 80% of nominal capacity, because thick sludge cannot be fully sucked out and sometimes has to be diluted.

Safety of sanitation workers

• Protective equipment: boots, heavy-duty gloves, waterproof overalls or apron, mask and eye protection against splashes, with a washing and disinfection station on site.
• Vaccination: tetanus and hepatitis B as a minimum, hepatitis A and typhoid depending on the context.
• No entry into a pit without a confined space protocol (toxic gases, lack of oxygen); give preference to long-handled tools and pumps.
• Decent working conditions: fair pay, no forced labour or work reserved for a stigmatised social group, working hours adapted to the heat.

In many contexts, pit emptiers belong to marginalised groups and work without protection. The WHO Guidelines on Sanitation and Health, together with the joint work of WHO, the World Bank and the ILO on the health and safety of sanitation workers, point out that protecting them is part of programme quality, not an optional extra.

6Worked example: the twelve-month sanitation plan for the Kalimbé site

We return to the fictional Kalimbé site (18,000 people, day 1). Hand-auger soundings and readings in wells show two very different areas: the northern area (15,000 people) on stable sandy-clay soil, with the water table at 8 m depth; the southern area (3,000 people), a lowland where the water table is at 2.5 m in the dry season and rises to 1.2 m in the rainy season. Focus group discussions indicate anal cleansing with water, strong reluctance among women to share latrines with unrelated men, and no solution for used sanitary pads, which are currently thrown into the pits.

Step 1: the acute phase (weeks 1 to 4)

• Days 1 to 3: two defecation areas demarcated by sex, downstream of water sources, with shovels and lime, handwashing points and supervision by hygiene workers recruited from the site.
• Week 1: 120 deep trench latrine cubicles built, i.e. 150 people per cubicle. The gap with the benchmark (50) is reported to the cluster with a catch-up schedule.
• Week 3: 360 cubicles in 60 blocks of 6 (benchmark of 50 people per cubicle reached). Each block has 4 cubicles for women, 1 for men and 1 accessible cubicle (ramp, wide door, grab bar), giving a ratio close to 3 to 1 for sex-segregated cubicles. Each block has solar lighting, internal locks, a handwashing station and a closed bin for menstrual products.

Checking the design life of a trench: effective volume of 0.8 × 6 × 2 = 9.6 m³ (excavated depth 2.5 m, freeboard 0.5 m). Users: 6 cubicles × 50 = 300 people. Accumulation rate used: 0.06 m³ per person per year, higher than the 0.04 benchmark to account for waste thrown in: 300 × 0.06 = 18 m³ per year. Design life: 9.6 ÷ 18 = 0.53 years, i.e. about six months. Family latrines must therefore be in place before the fifth month.

Step 2: shared latrines in the northern area (months 2 to 6)

After consultation, households choose latrines shared by four related or neighbouring households (about 20 people). Requirement: 15,000 ÷ 20 = 750 latrines.

• Effective volume for two years: 20 × 0.06 × 2 = 2.4 m³.
• Pit with a 1.2 m × 1.0 m cross-section: effective depth 2.0 m, excavated depth 2.5 m including freeboard.
• Water table check: 8 m − 2.5 m = 5.5 m between the bottom of the pit and the water table, above the minimum of 1.5 m.
• The top five courses of the pit lining are reinforced (sandbags or blocks) because of the moderate stability of the surface soil.

Step 3: the southern area, where conventional pits are impossible

With the water table at 1.2 m in the rainy season, no infiltrating pit can meet the 1.5 m separation distance. The team installs 150 raised latrines on 1.5 m³ sealed pits. The fill rate, measured on 20 latrines over three weeks, is about 1.5 litres per user per day (excreta, urine and anal cleansing water).

Reasoning: 10,500 dollars per month, i.e. 126,000 dollars per year, for 3,000 people, with a high risk of overflow if the truck breaks down during the rainy season. The team presents an alternative to the site manager, the CCCM cluster and representatives of the lowland area: voluntary relocation of the 600 households concerned to a 4-hectare extension on higher ground, negotiated with the town council, at an estimated one-off cost of 90,000 dollars (shelters, conventional shared latrines). After consultation, 420 households accept; the other 180 prefer to stay close to their fields. Raised latrines are kept for them, which brings emptying costs down to about 3,200 dollars per month.

Step 4: the faecal sludge treatment site

A 0.5-hectare plot is obtained 1.5 km downstream, more than 300 m from the nearest borehole and outside the flood zone. It comprises a lime mixing pit, four covered drying beds (two- to three-week rotation per bed), and a burial pit for dried sludge. The site is fenced and guarded, and its workers are equipped and vaccinated.

Step 5: monitoring

The point to watch in this table is perceived safety at night: even at 76%, one woman in four does not feel safe. The qualitative survey that follows shows that most incidents occur on the way to the latrine, not inside it. The response therefore depends as much on lighting the pathways and coordinating with protection actors as on the design of the cubicles.

7Solid waste, healthcare waste, drainage and vector control: the operational method

Household solid waste

A site of 18,000 people commonly produces several tonnes of waste a day, mostly packaging from distributions, food scraps and ash. Without management, it blocks drains, attracts rodents and flies, and ends up in the latrines. The method:

1. Characterise: for one week, weigh the waste from a sample of households and collection points (quantity per person, composition).
2. Reduce at source: work with distribution actors to limit packaging, and recover reusable cartons and bags.
3. Organise collection: one bin per household or group of households, communal collection points, collection at least twice a week (more often in hot weather), paid and equipped teams.
4. Dispose: refuse pits covered daily with a layer of soil for small sites, a controlled landfill outside the site for larger sites, in agreement with local authorities; open burning should be avoided (toxic fumes from plastics).
5. Recover value where possible: composting of organic waste, collection by local recycling chains, income-generating activities.

Healthcare waste

WASH teams are often responsible, together with health actors, for managing waste from health posts and treatment centres. Segregation at source is done into at least three categories, with a consistent colour code across the whole site:

The health facility's waste zone is fenced, locked, inaccessible to children and animals, and equipped with an incinerator or pits sized according to the volume produced. The WHO guide on the safe management of wastes from health-care activities is the reference.

Drainage

• Each water point has a sloping concrete apron and a channel leading to a soakaway or a garden. The sizing of a soakaway depends on the volume of greywater and the permeability of the soil (percolation test).
• Stormwater drainage is planned together with site design: following the contour lines, primary and secondary ditches, culverts, regular maintenance by paid teams before and during the rainy season.
• Shower and laundry areas have their own drainage.

Vector control

Any use of insecticide or larvicide must involve products prequalified by WHO and authorised in the country, applied by trained and protected people, in coordination with the health sector and the national malaria control programme. The "comfort" spraying demanded at the start of a crisis is rarely effective and can encourage resistance.

8Reusable tools and templates

Checklist for siting a latrine block

• At least 30 m from any well, borehole or spring catchment, and located hydraulically downstream where possible.
• Pit bottom at least 1.5 m above the highest level of the water table (measured in the rainy season or estimated with a margin).
• Less than 50 m from the shelters served; route lit, visible, with no isolated passages.
• Outside flood-prone areas and drainage lines.
• Location validated during a safety walk with women, adolescent girls and persons with disabilities.
• Agreement of the site manager and, where applicable, the landowner.
• Access possible for emptying (truck or manual equipment).

Monthly latrine observation sheet

Faecal sludge emptying and treatment register

Decommissioning plan for a full latrine

1. Inform users and bring the replacement latrine into service before closure.
2. Add lime or soil, then backfill with at least 0.5 m of compacted soil.
3. Recover the slab and superstructure if they are reusable, after cleaning and disinfection.
4. Mark the location (stake, paint) and record it on the site map so that no one digs in the same place.

Questions for a focus group discussion on sanitation

1. Where do members of your household go to the toilet, by day and at night? The children? Older people?
2. What prevents you from using the latrines (distance, smell, queues, fear, cleanliness)?
3. Who are you willing to share a latrine with? Who should not share it?
4. How do women and girls manage their periods? Where do they wash and dry their menstrual materials? Where do they dispose of them?
5. Who cleans the latrines today? How could cleaning be organised fairly?

9Common mistakes, donor expectations and adapting to contexts

Common mistakes

1. Counting latrines built rather than latrines used. A report showing 900 latrines with no data on use, functionality and safety tells the donor nothing about the project's effect.
2. Ignoring the downstream chain. Sealed pits without a vacuum truck, a truck without a treatment site, a treatment site without a permit: all situations that end in illegal dumping.
3. Designing for adult men. Squat holes too large for children, no bins for menstrual products, cubicles without lighting, accessible latrines built without consulting the people concerned.
4. Underestimating the water table. Readings taken in the dry season lead to pits that fill with water in the rainy season, contaminating nearby wells.
5. Neglecting cleaning. Communal latrines without a paid or organised cleaning system become dirty within days and are abandoned.
6. Applying development approaches out of context. Community-led total sanitation (CLTS), designed to end open defecation through mobilisation and without subsidies, is not suited to a displaced population with no land, no materials and no security of tenure. It may be suitable in host communities or in protracted crises, with caution.

What donors and evaluators look at

• Justified benchmarks and a clear trajectory: from 50 to 20 people per toilet, with a realistic timeline and the reasons for any gaps.
• Outcome indicators, not just output indicators: use, perceived safety, functionality, availability of water and soap, absence of open defecation.
• Data disaggregated by sex, age and disability, and evidence of consultation, in line with the Humanitarian Inclusion Standards for Older People and People with Disabilities and the Inter-Agency Standing Committee (IASC) Guidelines for Integrating Gender-Based Violence Interventions in Humanitarian Action.
• A faecal sludge management chain budgeted for the entire project duration, and the necessary environmental permits.
• The cost per person served and how it compares with the other options studied (the reasoning in the Kalimbé example).
• The protection of sanitation workers.

Variations by context

10Interview questions and key references

1. "How do you choose a sanitation option for a new site?"

A good answer lists the criteria (water table, soil, space, practices, duration, downstream chain), mentions concrete measurements (hand auger, existing wells, percolation test), separate consultation of women and men, and the phased approach, with an emptying plan from the design stage.

2. "The pits in a camp are full after nine months and there is no more space. What do you propose?"

The candidate proposes a rapid assessment of the condition of the pits, prioritisation, options for mechanical or safe manual emptying, an authorised treatment site, and a revision of the design (emptiable pits, alternating twin pits). They quantify the sludge volume and the truck trips, and think about worker safety.

3. "How do you know whether your latrines are safe for women and girls?"

The candidate cites safety walks, safety audits with groups of women and adolescent girls, a disaggregated perceived-safety indicator, links with protection and gender-based violence actors, and concrete changes made after feedback (lighting, location, locks).

4. "Why not apply community-led total sanitation in a camp for displaced people?"

The candidate explains the conditions for this approach (a stable community, land ownership, capacity to invest), their absence in a camp, the risk of social pressure on vulnerable people, and the cases where elements of the approach can be useful (host communities, protracted crises).

5. "What indicators would you put in a logframe for a six-month sanitation project?"

The candidate proposes a mix of output indicators (functional toilets, ratio of people per toilet) and outcome indicators (observed use, availability of water and soap, perceived safety, absence of open defecation), with baseline, target, disaggregation and data collection method.

Key references

• The Sphere Handbook (2018 edition), standards on excreta management, solid waste management and vector control: Sphere Association.
• Compendium of Sanitation Technologies in Emergencies: Eawag, German WASH Network, Global WASH Cluster and partners.
• Excreta Disposal in Emergencies (Peter Harvey): WEDC, Loughborough University.
• Guidelines on Sanitation and Health: World Health Organization.
• Safe Management of Wastes from Health-care Activities (second edition): World Health Organization.
• Health, Safety and Dignity of Sanitation Workers: An Initial Assessment: World Bank, ILO, WaterAid and WHO.
• Vector Control: Methods for Use by Individuals and Communities and guidance on vector control in emergencies: World Health Organization.
• Guidelines for Integrating Gender-Based Violence Interventions in Humanitarian Action, WASH thematic area: Inter-Agency Standing Committee (IASC).
• Humanitarian Inclusion Standards for Older People and People with Disabilities: Age and Disability Consortium.
• Menstrual Hygiene Management in Emergencies toolkit: Columbia University and International Rescue Committee.