Separate waste from water

These are the humanitarian standards, written from what worked and failed in camps of hundreds of thousands:

• At least 30 m from any well, spring or stream, and downhill and downstream of it. Faecal organisms travel further and faster through sand, gravel and fissured rock — increase the distance there.
• The pit floor at least 1.5 m above the wet-season water table. Check the season, not the day: a pit that reaches groundwater is not a latrine, it is an injection well.
• No more than 50 m from where people sleep, and safe to reach after dark. A latrine that is frightening at night is not used at night.
• No more than 20 people per pit. Past that, queues and filth drive people back to open defecation and the whole barrier fails.

Sludge accumulates at roughly 40–60 litres per person per year.

Worked example. Six people, five years, 60 litres each: 6 × 5 × 60 = 1,800 litres = 1.8 m³. A pit 1.0 m × 1.0 m × 2.5 m deep holds 2.5 m³ — enough, with the top half-metre deliberately left empty as freeboard.

Dig the next pit before the current one is full, not after. A group that has to dig in a hurry digs it in the wrong place.

Dig the pit to the planned depth, keeping the sides vertical. Line the top 0.5 m with brick, stone, timber or a mud-and-stick collar — that is where collapse starts, and a collapsing pit mouth is how people fall in.

Lay a slab or stout timbers with a squat hole about 30 × 15 cm, positioned so it can be straddled naturally, and make a cover for the hole that seals it when not in use. Keep the excavated spoil in a heap beside the door with a scoop stuck in it.

Build a screen for privacy before the first use, not after. Privacy is not a luxury here; it is the difference between a latrine being used and being avoided.

A scoop of soil or wood ash after every use, every time, by everyone. This is the whole difference between a pit that controls flies and smell and one that breeds them.

Ash is better than soil: it is alkaline, it dries the surface, it suppresses smell, and flies dislike it. A fire that is burning anyway produces all you need.

The rule has to be stated out loud, taught to children, and followed by the people the group takes its cues from. Habits here are set in the first week and are very hard to change afterwards.

Handwashing with soap cuts diarrhoeal illness by roughly 30–45% — the largest single effect available — but only if it happens at the moment it matters, which means at the latrine door, not at the camp.

Build a tippy tap: two forked uprights about 1.5 m tall, a crossbar, a 3–5 litre container hung by its neck with a 2 mm hole punched below the cap, and a foot cord to tip it. Hands never touch the container. It uses about 40 ml of water per wash. Hang soap on a string, or ash in a tin, and dig a small gravel soakaway underneath so it does not make a mud puddle and a mosquito breeding site.

The five moments: after defecating, after cleaning a child, before preparing food, before eating, before feeding a child.

House flies go from egg to adult in 7–10 days in warm weather, breed in faeces and rotting food, and carry pathogens on their feet directly from one to the other.

That short cycle is the opportunity: remove everything they can breed in and the population collapses within about two weeks. Cover the pit contents, cover and bury food waste, keep a covered refuse pit at least 30 m from water and dwellings, and cover prepared food. Keep the latrine and the kitchen far apart and never carry the same tools between them.

One case becomes ten through hands and shared water. The moment someone has watery diarrhoea:

• Isolate the sick person's waste and washing. A dedicated pot, dedicated water, emptied into the latrine, and hands washed by whoever handles it.
• Rehydrate, hard. Oral rehydration solution: 1 litre of safe water, 6 level teaspoons of sugar, half a level teaspoon of salt. If it tastes saltier than tears, remake it. Give 50–100 ml after every loose stool for a child under two, 100–200 ml for ages 2–10, as much as wanted for anyone older. Keep breastfeeding.
• Give children zinc if any exists — 20 mg a day for 10–14 days shortens the illness.
• Blood in the stool means dysentery and needs antibiotics if any can be reached.

The sanitation guide carries the dehydration signs that say when this has stopped being manageable at home.

When the contents reach 0.5 m below the slab, stop using it. Lift the slab for the next pit, backfill with at least 0.5 m of soil, mounded so it sheds rain and settles rather than ponding, and mark it.

Nothing edible is planted on it for two years, and nothing is built on it — the ground is soft and the contents are not safe until time has done the work. A tree, on the other hand, is an excellent use of it.

The next pit is already dug, because entry 2 said so.