Sanitation refers to public health conditions that involve clean drinking water and the proper handling and disposal of human waste and sewage. Keeping people away from feces and washing hands with soap are important parts of sanitation. Sanitation systems help protect health by creating clean environments that stop the spread of diseases, especially those passed through contact with feces and then touching the mouth. For example, diarrhea, a major cause of poor nutrition and slow growth in children, can be reduced with good sanitation. Many other diseases, such as intestinal worm infections, cholera, hepatitis, polio, schistosomiasis, and trachoma, are more likely to spread in areas with poor sanitation.

There are many types of sanitation systems and methods. Examples include community-led total sanitation, container-based sanitation, ecological sanitation, emergency sanitation, environmental sanitation, onsite sanitation, and sustainable sanitation. A sanitation system includes collecting, storing, moving, treating, and safely disposing of or reusing human waste and wastewater. Reusing resources like nutrients, water, energy, or organic matter from waste is called the "sanitation value chain" or "sanitation economy." People who clean, maintain, operate, or empty sanitation systems are called "sanitation workers."

Sanitation levels are used to compare how well sanitation services work in different countries. A system called the "sanitation ladder," created in 2016, starts with open defecation and moves upward through categories like "unimproved," "limited," "basic," and the highest level, "safely managed." This system is especially important in developing countries.

In 2010, the United Nations General Assembly recognized the human right to water and sanitation. Sanitation is a key global goal and part of Sustainable Development Goal 6. According to a 2017 report, about 4.5 billion people worldwide lack access to safely managed sanitation. Poor sanitation affects not only health but also dignity and personal safety.

Definitions

The term "sanitation" can have different meanings depending on the country or organization. According to the World Health Organization, sanitation includes four types of systems: managing human waste, handling wastewater (including treatment plants), managing solid waste, and managing rainwater drainage, also called stormwater drainage. However, some groups in the WASH sector only focus on managing human waste when they define sanitation.

The Sphere handbook describes sanitation as part of the "Water Supply, Sanitation and Hygiene Promotion" (WASH) sector during humanitarian crises. This sector includes hygiene promotion, providing clean water, managing human waste, controlling disease-carrying pests, managing solid waste, and ensuring hygiene during disease outbreaks and in healthcare settings.

Many people consider hygiene promotion a key part of sanitation. The Water Supply and Sanitation Collaborative Council defines sanitation as the collection, transportation, treatment, and disposal or reuse of human waste, wastewater, and solid waste, along with promoting hygiene.

Although wastewater treatment is part of sanitation, the two terms are often used together as "sanitation and wastewater management."

A 1998 DFID manual explains that sanitation includes personal and public hygiene. Personal sanitation involves tasks like managing menstrual waste, cleaning household toilets, and handling household garbage. Public sanitation includes collecting and treating garbage (municipal waste), cleaning drains, streets, schools, public restrooms, and sewers, as well as operating sewage treatment plants. People who perform these tasks for others are called sanitation workers.

Purposes

The main goals of sanitation are to create a healthy environment for all people, protect natural resources like surface water, groundwater, and soil, and ensure safety, security, and dignity when people use the toilet.

In 2010, the United Nations General Assembly recognized the Human Right to Water and Sanitation. This right is supported by international laws, including treaties, declarations, and other standards. It is based on the human right to have a basic standard of living.

Good sanitation systems prevent human waste from coming into contact with people, which stops the spread of diseases. This idea is shown in the F-diagram, which lists the main ways diseases spread through the fecal-oral route. These include feces, fingers, flies, fields, fluids, and food.

Sanitation systems must be designed to fit the needs of the people who use them and the resources available in their area.

Sanitation technologies can include large structures, such as sewer systems, sewage treatment plants, and landfills. These systems handle wastewater and solid waste. Other technologies may be simpler, like pit latrines or non-flush toilets, which manage waste on-site.

Providing sanitation requires looking at the entire system, not just the toilet or waste treatment parts. The "sanitation chain" includes the user’s experience, how waste is collected, how it is moved and treated, and how it is reused or disposed of. All these parts must be carefully planned.

Managing human waste has many benefits for public health and the environment. For every $1 spent on sanitation, society gains about $5.50 in return.

In developing countries, poor sanitation causes major economic problems. For example, a World Bank study found that inadequate sanitation costs India about 6.4% of its GDP each year. These costs include early deaths, time lost from poor access to toilets, lower productivity, higher healthcare costs, and lost tourism revenue. Poor sanitation also harms the poorest people, women, and children the most. Having a toilet at home helps women improve their education and work opportunities.

Types and concepts (for excreta management)

The term sanitation is connected with various adjectives to describe different types of sanitation systems. These systems may focus only on managing human waste or include handling greywater (wastewater from sinks and showers), stormwater, and solid waste. Here are the terms in alphabetical order:

In 2017, the Joint Monitoring Program (JMP) introduced a new term: "basic sanitation service." This refers to the use of improved sanitation facilities that are not shared with other households. A lower level of service is now called "limited sanitation service," which involves using improved facilities shared between two or more households.

Container-based sanitation (CBS) collects human waste in sealed, removable containers (called cartridges) that are transported to waste treatment facilities. This system uses commercial services that provide portable toilets and replace full containers with empty ones. The service safely disposes of or reuses collected waste. Users usually pay for the collection. With proper planning and partnerships, CBS can offer safe waste management at a lower cost than building sewers. In most cases, CBS uses urine-diverting dry toilets.

Community-based sanitation is related to decentralized wastewater treatment (DEWATS).

Community-led total sanitation (CLTS) is a method used in developing countries to improve hygiene and sanitation in communities. CLTS encourages people to stop open defecation (pooping outside) through a process called "triggering," which uses methods like building simple toilets (such as pit latrines) to inspire change. CLTS helps communities feel proud of their progress while reducing shame about open defecation. It works without giving money for hardware, instead helping communities solve the problem of open defecation together.

The term "dry sanitation" is not widely used and is not clearly defined. It usually refers to systems that use dry toilets and no sewers to transport waste. When people mention "dry sanitation," they often mean systems using urine-diverting dry toilets (UDDTs).

Ecological sanitation, also called ecosan or resource-oriented sanitation, is an approach that safely reuses human waste in agriculture. It focuses on returning nutrients and organic matter from waste to the soil and water in a safe way. Ecosan aims to reduce the use of non-renewable resources. When properly designed, ecosan systems convert human waste into safe nutrients for soil and water.

Emergency sanitation involves managing and providing sanitation during crises, such as for refugees, disaster victims, or displaced people. There are three phases: immediate, short term, and long term. In the immediate phase, the focus is on stopping open defecation, using simple toilets like pit latrines or bucket toilets. In the short term, systems like urine-diverting dry toilets or septic tanks may be used. Handwashing facilities and managing fecal sludge (waste from toilets) are also part of emergency sanitation.

Environmental sanitation includes controlling factors in the environment that spread disease. This includes managing solid waste, treating water and wastewater, handling industrial waste, and controlling noise pollution. According to the World Health Organization (WHO), environmental sanitation involves controlling harmful factors in the environment that affect human health. Its main goal is to protect public health.

Fecal sludge management (FSM) involves storing, collecting, transporting, treating, and safely reusing or disposing of fecal sludge (waste from toilets). FSM includes all steps from collection to disposal, forming a "value chain." Fecal sludge comes from systems like pit latrines, septic tanks, and container-based solutions, not from sewers. It includes human waste, flushwater, toilet paper, menstrual products, greywater (bathing or cooking water), and other waste. Fecal sludge removed from septic tanks is called septage.

Improved sanitation refers to managing human waste at the household level. The term was created by the Joint Monitoring Program (JMP) in 2002 to track progress toward the Millennium Development Goals (MDGs). It is different from "safely managed sanitation service." The opposite of improved sanitation is "unimproved sanitation." These terms are also used to monitor progress toward Sustainable Development Goal 6 (Target 6.2, Indicator 6.2.1) since 2015.

Lack of sanitation means no toilets or no hygienic toilets available. This often leads to open defecation, which causes serious health problems. As of 2015, about 2.4 billion people lacked improved sanitation, including 660 million without access to safe drinking water.

Onsite sanitation (or on-site sanitation) is a system where waste and wastewater are collected, stored, or treated on the property where they are generated. Another term for this is non-sewered sanitation systems (NSSS), which are common in many countries. NSSS are important for managing fecal sludge, making up about half of all sanitation systems. The level of treatment varies, from no treatment (like pit latrines) to advanced treatment (like septic tanks). Onsite systems may connect to fecal sludge management (FSM) systems, where waste is treated offsite. Wastewater is only generated when piped water is available in buildings or nearby.

Other types, concepts and systems

Managing wastewater includes collecting dirty water, cleaning it, and then either throwing it away or using it again. This process is also called water reclamation. In cities of developed countries, wastewater is collected through gravity-powered sewers, then cleaned at treatment plants before being released into rivers, lakes, or the sea. In many developing countries, wastewater is often released into the environment without being cleaned first. Other options for handling wastewater instead of using large sewer systems include using toilets that handle waste on-site, smaller systems for local areas, and dry toilets connected to systems that manage solid waste.

Sewers can be connected to systems that also handle rainwater or kept separate as sanitary sewers. Combined sewers are often found in older parts of cities. Heavy rain and poor maintenance can cause overflow problems, leading to raw sewage being released into the environment. Industries sometimes send their wastewater into public sewers, which can make it harder to clean the water unless the industries clean their waste first before sending it to sewers.

Most solid waste is thrown into landfills, but other methods include burning it, recycling, composting, and turning it into fuel. In developed countries, landfills follow strict rules about covering waste with soil each day to reduce germs, smells, and litter. These countries also use clay-like soil to seal landfills and stop harmful liquids from polluting groundwater. In less developed countries, these rules are usually not as strict.

Burning waste can release harmful air pollutants. Recycling and making fuel from waste are better choices because they are more environmentally friendly and cost-effective over time. Composting is useful but depends on how much people want to buy compost.

In the food industry, keeping surfaces clean is important to remove germs that can make people sick and to keep food safe. In the United States, food companies must follow strict rules about cleaning. In Japan, food safety is ensured by following hygiene laws.

In food and medicine-making industries, "sanitary equipment" refers to tools that can be fully cleaned and sterilized without being taken apart. These tools are designed to avoid areas where cleaning is hard, and they are often made of stainless steel that is polished to reduce germs.

Having sanitation facilities alone does not always improve health. Studies show that how people practice hygiene can affect their health as much as having clean facilities. Teaching people good hygiene habits is important for reducing diseases linked to water, sanitation, and hygiene. This involves helping people learn about hygiene, involving communities in managing services, and providing necessary supplies and tools.

Health aspects

The World Health Organization (WHO) has studied how much of the world’s illness and deaths are caused by poor access to clean water, sanitation, and hygiene (WASH). In their research, they looked at four main health problems: diarrhea, acute respiratory infections, malnutrition, and soil-transmitted helminthiasis (STHs). These health issues are part of a measure used to track progress toward Sustainable Development Goal 3, which aims to improve global health and well-being. This measure, called Indicator 3.9.2, tracks the number of deaths caused by unsafe water, poor sanitation, and lack of hygiene.

In 2023, the WHO reported findings from 2019: Using safe WASH services could have prevented at least 1.4 million deaths and 74 million disability-adjusted life years (DALYs) linked to these four health problems. This accounts for 2.5% of all global deaths and 2.9% of all DALYs. Among the four health issues studied, diarrhea had the strongest connection to poor WASH. It was linked to over 1 million deaths and 55 million DALYs. Of these deaths, 564,000 were specifically tied to unsafe sanitation.

Environmental aspects

When studying environmental samples, scientists use certain types of organisms to check for fecal pollution. For water testing, common indicators include the bacterium Escherichia coli (E. coli) and non-specific fecal coliforms. For soil, sewage sludge, biosolids, or fecal matter from dry toilets, helminth eggs are often used as indicators. In helminth egg testing, eggs are first removed from the sample. Then, a test is performed to determine if the eggs are alive or not. The number of alive eggs in the sample is then counted.

Global mechanisms

In 2016, the Sustainable Development Goals (SDGs) replaced the Millennium Development Goals (MDGs). Sanitation is a global priority and is part of SDG 6, which focuses on "clean water and sanitation for all" by 2030. In 2015, it was estimated that 660 million people still did not have access to safe drinking water.

Since the start of the COVID-19 pandemic in 2020, access to clean water and sanitation has become even more important. Handwashing is a key way to prevent the spread of the virus, but two out of five people globally do not have access to a hand-washing station.

The United Nations created the Millennium Development Goals (MDGs) in 2000 and 2002 to help reduce poverty and support sustainable development. One of the MDGs aimed to halve the number of people without access to clean water and sanitation by 2015, compared to 1990. However, progress toward this goal has been slow, as shown by reports from the Joint Monitoring Programme (JMP) and the United Nations Development Programme (UNDP) in 2006.

In 2006, the United Nations General Assembly declared 2008 as "The International Year of Sanitation" to raise awareness and encourage action to meet sanitation goals.

Sanitation has not received enough political attention compared to other issues, even though it is critical for health and development. Water supply projects are often prioritized over sanitation efforts.

The JMP, a program run by WHO and UNICEF, has published reports every two years since 1990 to track progress on water and sanitation access. In 2015, the JMP reported:
– Open defecation rates dropped globally from 38% in 1990 to 25% in 2015. About 946 million people still practiced open defecation in 2015.
– In 2015, 82% of urban populations and 51% of rural populations used improved sanitation facilities, as defined by the JMP.

In 2011, the Bill & Melinda Gates Foundation started the "Reinvent the Toilet Challenge" to develop new technologies for treating human waste. Examples include the Omni Processor and technologies for managing fecal sludge. In 2015, the foundation released a report titled "Building demand for sanitation" to outline their strategy for improving water, sanitation, and hygiene.

New innovations in sanitation, currently being tested, include locally made alcohol-based hand rub, improved latrines, and container-based sanitation systems. These initiatives have been recognized by the Centers for Disease Control and Prevention (CDC), the U.S. public health agency.

Capacity development, or building skills and knowledge, is a key way to improve sanitation progress. For example, in India, the Sanitation Capacity Building Platform (SCBP) was created with support from the Bill & Melinda Gates Foundation from 2015 to 2022. This project showed that learning on the job and in a supportive work environment helps build capacity most effectively. Capacity development also requires strong policies, funding, and partnerships to turn training into real improvements in sanitation programs and infrastructure. The Capacity Development Effectiveness Ladder Framework (CDEL) outlines five steps for successful capacity development: creating learning materials, building partnerships, designing learning strategies, planning for change, and contributing to global discussions on capacity development.

Costs

A study was done in 2018 to compare the costs of full sanitation systems in developing cities in Africa and Asia. It showed that traditional sewer systems are usually the most expensive option. Next in cost are systems with septic tanks, then ventilated improved pit latrines (VIP), followed by urine diversion dry toilets, and finally pour-flush pit latrines. The main factors that affect the cost of urban sanitation include: the type of technology used, labor costs, material and utility costs, population density, land shape, the level of service provided by the system, soil conditions, energy costs, and other factors such as distance to wastewater treatment facilities, climate, how treated water is used, business models, and water table height.

Some local groups have tested community-managed toilet blocks where households pay for construction and maintenance. A study in Mumbai’s informal settlements found that $1.58 per adult would cover construction costs, and less than $1 per household per month would cover maintenance costs.

History

Major human settlements could first grow only in places where fresh surface water was available, such as near rivers or natural springs. People throughout history created systems to bring water to their communities and homes, and to remove and later treat wastewater. The main goal of sewage treatment at that time was to carry raw sewage to a natural body of water, like a river or ocean, where it would mix with the water and spread out.

An example of public water and sanitation systems from the Bronze Age (3300–1300 BCE) is the Sanitation in the Indus Valley Civilization in Asia. Ancient Rome had highly developed sanitation systems, including stone and wooden drains to collect and remove wastewater from populated areas. For example, the Cloaca Maxima in Rome carried wastewater into the River Tiber. The first sewers in ancient Rome were built between 800 and 735 BCE.

Society and culture

Many jobs are involved in the area of sanitation. For example, on the technical and operations side, some jobs include sanitation workers, waste collectors, and sanitary engineers.