Septic tank in the context of "Sludge"

Emergency sanitation is the management and technical processes required to provide sanitation in emergency situations. Emergency sanitation is required during humanitarian relief operations for refugees, people affected by natural disasters and internally displaced persons. There are three phases of emergency response: Immediate, short term and long term. In the immediate phase, the focus is on managing open defecation, and toilet technologies might include very basic latrines, pit latrines, bucket toilets, container-based toilets, chemical toilets. The short term phase might also involve technologies such as urine-diverting dry toilets, septic tanks, decentralized wastewater systems. Providing handwashing facilities and management of fecal sludge are also part of emergency sanitation.

The immediate sanitation phase focuses on the provision of proper waste management resources. The main course of action during this stage is reducing open defecation. It is implemented as a course of initial action in emergency situations and it lasts from one to three months. Toilets provided might include very basic Latrines, pit latrines, Bucket toilets, container-based toilets or Chemical toilets.

A toilet is a piece of sanitary hardware that collects human waste (urine and feces) and sometimes toilet paper, usually for disposal. Flush toilets use water, while dry or non-flush toilets do not. They can be designed for a sitting position popular in Europe and North America with a toilet seat, with additional considerations for those with disabilities, or for a squatting posture more popular in Asia, known as a squat toilet. In urban areas, flush toilets are usually connected to a sewer system; in isolated areas, to a septic tank. The waste is known as blackwater and the combined effluent, including other sources, is sewage. Dry toilets are connected to a pit, removable container, composting chamber, or other storage and treatment device, including urine diversion with a urine-diverting toilet. "Toilet" or "toilets" is also widely used for rooms containing only one or more toilets and hand-basins. Lavatory is an older word for toilet.

The technology used for modern toilets varies. Toilets are commonly made of ceramic (porcelain), concrete, plastic, or wood. Newer toilet technologies include dual flushing, low flushing, toilet seat warming, self-cleaning, female urinals and waterless urinals. Japan is known for its toilet technology. Airplane toilets are specially designed to operate in the air. The need to maintain anal hygiene post-defecation is universally recognized and toilet paper (often held by a toilet roll holder), which may also be used to wipe the vulva after urination, is widely used (as well as bidets).

Sewage treatment is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable to discharge to the surrounding environment or an intended reuse application, thereby preventing water pollution from raw sewage discharges. Sewage contains wastewater from households and businesses and possibly pre-treated industrial wastewater. There are a large number of sewage treatment processes to choose from. These can range from decentralized systems (including on-site treatment systems) to large centralized systems involving a network of pipes and pump stations (called sewerage) which convey the sewage to a treatment plant. For cities that have a combined sewer, the sewers will also carry urban runoff (stormwater) to the sewage treatment plant. Sewage treatment often involves two main stages, called primary and secondary treatment, while advanced treatment also incorporates a tertiary treatment stage with polishing processes and nutrient removal. Secondary treatment can reduce organic matter (measured as biological oxygen demand) from sewage,  using aerobic or anaerobic biological processes. A quaternary treatment step (sometimes referred to as advanced treatment) can also be added for the removal of organic micropollutants, such as pharmaceuticals. This has been implemented in full-scale in Sweden.

A large number of sewage treatment technologies have been developed, mostly using biological treatment processes. Design engineers and decision makers need to take into account technical and economical criteria of each alternative when choosing a suitable technology. Often, the main criteria for selection are desired effluent quality, expected construction and operating costs, availability of land, energy requirements and sustainability aspects. In developing countries and in rural areas with low population densities, sewage is often treated by various on-site sanitation systems and not conveyed in sewers. These systems include septic tanks connected to drain fields, on-site sewage systems (OSS), and vermifilter systems. On the other hand, advanced and relatively expensive sewage treatment plants may include tertiary treatment with disinfection and possibly even a fourth treatment stage to remove micropollutants.

Nutrient pollution is a form of water pollution caused by too many nutrients entering the water. It is a primary cause of eutrophication of surface waters (lakes, rivers and coastal waters), in which excess nutrients, usually nitrogen or phosphorus, stimulate algal growth. Sources of nutrient pollution include surface runoff from farms, waste from septic tanks and feedlots, and emissions from burning fuels. Raw sewage, which is rich in nutrients, also contributes to the issue when dumped in water bodies. Excess nitrogen causes environmental problems such as harmful algal blooms, hypoxia, acid rain, nitrogen saturation in forests, and climate change.

Agricultural production relies heavily on the use of natural and synthetic fertilizers, which often contain high levels of nitrogen, phosphorus and potassium. When nitrogen and phosphorus are not fully used by the growing plants, they can be lost from the farm fields and negatively impact air and downstream water quality. These nutrients can end up in aquatic ecosystems and contribute to increased eutrophication.

Fecal sludge management (FSM) (or faecal sludge management in British English) is the storage, collection, transport, treatment and safe end use or disposal of fecal sludge. Together, the collection, transport, treatment and end use of fecal sludge constitute the "value chain" or "service chain" of fecal sludge management. Fecal sludge is defined very broadly as what accumulates in onsite sanitation systems (e.g. pit latrines, septic tanks and container-based solutions) and specifically is not transported through a sewer. It is composed of human excreta, but also anything else that may go into an onsite containment technology, such as flushwater, cleansing materials (e.g. toilet paper and anal cleansing materials), menstrual hygiene products, grey water (i.e. bathing or kitchen water, including fats, oils and grease), and solid waste. Fecal sludge that is removed from septic tanks is called septage.

It is estimated that one-third of the world's population is served by onsite sanitation, and that in low-income countries less than 10% of urban areas are served by sewers. In low-income countries, the majority of fecal sludge is discharged untreated into the urban environment, placing a huge burden on public and environmental health. Hence, FSM plays a critical role in safely managed sanitation and the protection of public health. FSM services are provided by a range of formal and informal private sector services providers, local governments, water authorities, and public utilities. This can also result in unreliable services with relatively high costs at the household level.

Onsite sewage facilities (OSSF), also called septic systems, are wastewater systems designed to treat and dispose of effluent on the same property that produces the wastewater, in areas not served by public sewage infrastructure.

A septic tank and drainfield combination is a fairly common type of on-site sewage facility in the Western world. OSSFs account for approximately 25% of all domestic wastewater treatment in the US. Onsite sewage facilities may also be based on small-scale aerobic and biofilter units, membrane bioreactors or sequencing batch reactors. These can be thought of as scaled down versions of municipal sewage treatment plants, and are also known as "package plants."

A portable or mobile toilet (colloquial terms: thunderbox, porta-john, porta-potty or porta-loo) is any type of toilet that can be moved around, some by one person, some by mechanical equipment such as a truck and crane. Most types do not require any pre-existing services or infrastructure, such as sewerage, and are completely self-contained. The portable toilet is used in a variety of situations, for example in urban slums of developing countries, at festivals, for camping, on boats, on construction sites, and at film locations and large outdoor gatherings where there are no other facilities. Most portable toilets are unisex single units with privacy ensured by a simple lock on the door. Some portable toilets are small molded plastic or fiberglass portable rooms with a lockable door and a receptacle to catch the human excreta in a container.

A portable toilet is not connected to a hole in the ground (like a pit latrine), nor to a septic tank, nor is it plumbed into a municipal system leading to a sewage treatment plant. The chemical toilet is probably the most well-known type of portable toilet, but other types also exist, such as urine-diversion dehydration toilets, composting toilets, container-based toilets, bucket toilets, freezing toilets and incineration toilets. A bucket toilet is a very simple type of portable toilet.

A chemical toilet collects human waste in a holding tank and uses chemicals to minimize odors. They do not require a connection to a water supply and are used in a wide variety of situations. These toilets are usually, but not always, self-contained and movable. A chemical toilet is structured around a relatively small tank, which requires frequent emptying. It is not connected to a hole in the ground (like a pit latrine), nor to a septic tank, nor is it plumbed into a municipal system leading to a sewage treatment plant. When the tank is emptied, the contents are usually pumped into a sanitary sewer or directly to a treatment plant.

The enclosed portable toilets used on construction sites and at large gatherings such as music festivals are well-known types of chemical toilets. As they are usually used for short periods and because of their high prices, they are mostly rented rather than bought, often including servicing and cleaning.