A latrine is a toilet system that collects and contains human waste on-site, rather than piping it away through a sewer. In its simplest form, it’s a hole dug in the ground with some kind of structure built over it for privacy. But latrines range from basic pits to engineered systems with ventilation, water seals, and composting chambers. They remain the primary form of sanitation for billions of people worldwide and have been used in some form for thousands of years.
How a Latrine Differs From a Toilet
The core distinction is where the waste goes. A conventional flushing toilet connects to a sewer system that carries waste off-site to a treatment plant. This requires reliable plumbing, a steady water supply, and expensive infrastructure. A latrine handles waste where it’s produced. It either stores waste in a pit below ground, treats it through decomposition, or contains it until it can be emptied and hauled away.
In areas where piped water is collected from a well or standpost, sewered systems simply aren’t feasible. Latrines fill that gap. The upfront cost is generally a single payment for construction, far less than the long infrastructure runs that sewer systems demand. That said, emptying a full latrine pit can be a significant expense on its own.
Common Types of Latrines
Not all latrines are just a hole in the ground. Several engineered designs address specific problems like odor, flies, and groundwater contamination.
Simple Pit Latrine
The most basic version: a pit dug into the earth, topped with a slab or platform and an enclosure for privacy. When the pit fills up, the structure is moved to a new pit and the old one is covered with soil. A typical pit with about 2.5 cubic meters of storage (roughly one meter wide and three meters deep) can last up to 10 years before it needs emptying or replacement, though in waterlogged conditions that timeline can shrink to as little as two and a half years.
Ventilated Improved Pit (VIP) Latrine
This design adds a vertical vent pipe extending above the roof of the latrine enclosure, with a fly screen at the top. Wind passing over the pipe creates airflow that draws odors up and out of the pit rather than into the enclosure. The fly screen traps insects that are attracted to the top of the pipe by light, preventing them from entering or leaving the pit. The enclosure itself is kept deliberately dim so that flies inside the pit move toward the light at the top of the vent pipe rather than through the squat hole. For these features to work properly, specific construction guidelines need to be followed, including using vent pipes of at least 150 millimeters in diameter and keeping windows free of insect screens that would block airflow.
Pour-Flush Latrine
This type uses a small water seal (similar to the U-bend under a sink) to block odors and flies from rising out of the pit. Instead of a mechanical flush, you pour water by hand to push waste through. It uses roughly 7 liters of water per use, far less than a conventional cistern toilet but still requiring a reliable water source.
Composting Latrine
Composting latrines break down waste through aerobic decomposition, the same biological process that turns garden waste into soil. The system relies on maintaining the right balance of carbon and nitrogen, along with controlled moisture (40 to 65 percent) and adequate airflow. Bacteria and fungi do the work in two phases: an initial warm-up period lasting a few days, followed by a hotter phase (reaching 40 to 60 degrees Celsius) that can last several months. During this hotter stage, the organisms break down fats, proteins, and cellulose. The World Health Organization recommends composting at 50°C for two weeks, then at 55 to 60°C for a month, with another two to four months of curing after that. The end product is a dark, stable material resembling rich organic soil that can be used as fertilizer.
The Public Health Impact
The primary purpose of any latrine is separating human waste from human contact. When waste contaminates water sources, food, or soil, it spreads diseases like cholera, typhoid, and dysentery. The question of how much latrines actually reduce illness has been studied extensively.
A large systematic review found that sanitation improvements reduce childhood diarrhea by about 25 percent on average. But the details matter enormously. When at least 75 percent of a community adopts improved sanitation, that reduction jumps to 45 percent. Below that threshold, the benefit drops to around 24 percent, meaning a single household latrine does less good if neighbors are still practicing open defecation. A trial in Bangladesh found a 39 percent decrease in childhood diarrhea after a sanitation intervention, dropping weekly prevalence from 5.7 to 3.5 percent. Full sewerage connections, where available, showed the most dramatic effect: a 64 percent reduction in diarrhea on average.
The takeaway is that latrines work best as a community-wide solution, not just an individual one.
Where Latrines Fall on the Sanitation Scale
The WHO and UNICEF classify sanitation into tiers. A pit latrine with a proper slab, a VIP latrine, a pour-flush latrine connected to a pit, and a composting toilet all count as “improved” sanitation facilities, meaning they’re designed to hygienically separate waste from human contact. A pit latrine without a slab or platform, a hanging latrine (suspended over water), or a bucket latrine is classified as “unimproved.”
To reach the top tier, “safely managed,” the facility must not be shared with other households, and the waste must be treated in place, stored and emptied for off-site treatment, or connected to a sewer with proper treatment. If the latrine is improved but the waste isn’t safely handled, it’s classified as “basic” sanitation. Many latrines in practice fall into this middle category.
Maintenance and Emptying
A latrine isn’t a build-and-forget system. Pits fill up, and what happens next depends on the design and local conditions. Data from Dar es Salaam, Tanzania, found that emptying frequency varies by construction type. Unlined pits lasted about 8 years on average before needing to be emptied, partially lined pits about 6.5 years, and drum or tire-based pits only about 4.7 years. Fully lined pits, which prevent waste from seeping into surrounding soil, lasted around 8.5 years.
Emptying is one of the most challenging parts of latrine sanitation. In dense urban areas, access for pumping trucks can be limited. Manual emptying carries serious health risks for workers. And the removed waste still needs safe treatment and disposal, a step that’s frequently skipped in practice.
Latrines in History
Communal latrines were a feature of Roman life. At sites like Housesteads Fort on Hadrian’s Wall, soldiers sat on wooden boards with holes cut into them, positioned over a long trench. Water ran through a ditch at their feet and carried waste into a central channel connected to the main sewer system, which ultimately drained into a river. The Romans even recycled bathhouse wastewater to help flush these public latrines. Long bench-like seats with keyhole-shaped openings offered little privacy. For cleaning, users shared sponges on sticks, rinsed in buckets of water mixed with salt or vinegar.
These ancient systems were remarkably sophisticated in their engineering, yet the basic principle hasn’t changed: keep human waste away from living spaces, food, and drinking water. Modern latrines accomplish this with better materials and design, but the core challenge of safely managing what goes into the pit remains the same one Roman engineers grappled with over two thousand years ago.