fecal sludge management fecal sludge management 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. fecal sludge being pumped out of a pit latrine in durban, south africa 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. fecal sludge collection can be arranged on a scheduled basis or on a call-for-service basis (also known as on-demand, on-request, or non-scheduled services). the collected fecal sludge may be manually or mechanically emptied, and then transported to treatment plants with a vacuum truck, a tank and pump mounted on a flatbed truck, a small tank pulled by a motorcycle, or in containers on a handcart. the wider use of multiple decentralized sludge treatment facilities within cities (to avoid long haulage distances) is currently being researched and piloted. fecal sludge is different to wastewater and cannot simply be co-treated at sewage treatment plants. small additions of fecal sludge are possible if plants are underutilized and able to take the additional load, and facilities to separate liquids and solids are available. a variety of mechanized and non-mechanized processing technologies may be used, including settling tanks, planted and unplanted drying beds, and waste stabilization ponds. the treatment process can produce resource recovery end-products such as treated effluent that can be used for irrigation, co-composting as a soil conditioner, anaerobic digestion for the production of biogas, forms of dry-combustion fuel such as pellets or biochar, charcoal, biodiesel, sludge and plants or protein production as animal fodder. definitions fecal sludge management refers to the storage, collection, transport, treatment, and safe end use or disposal of fecal sludge.: 3 collectively, the collection, transport, treatment and end use or reuse of excreta constitute the "value chain" of fecal sludge management. fecal sludge fecal sludge is defined very broadly as what accumulates in onsite sanitation technologies 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 and menstrual hygiene products, grey water (i.e. bathing or kitchen water, including fats, oils and grease), and solid waste. hence, fecal sludge is highly variable, with a very wide range of quantities (i.e. produced and accumulated volumes) and qualities (i.e. characteristics).: 3 fecal sludge is stored onsite, and is periodically collected and transported to a fecal sludge treatment plant, followed by safe disposal or end use. when safely managed, fecal sludge that is collected from pit latrines can also be called "pit latrine sludge", whereas fecal sludge collected from septic tanks can also be called "septic tank sludge" or "septage".: 5 septage septage or "septic tank sludge" is fecal sludge that is accumulated and stored in a septic tank. septage tends to be more dilute, as septic tanks are typically used with flush toilets (blackwater) and can also include grey water. septic tanks also tend to have less solid waste, as they only receive things that can be flushed down a toilet (e.g. toilet paper). when operating as designed, a sludge blanket layer accumulates on the bottom of the tank, a scum layer that contains fats, oil and grease accumulates at the top, and the effluent or supernatant contains less solids. septage is periodically removed (with a frequency depending on tank capacity, system efficiency, and usage level, but typically less often than annually) from the septic tanks by specialized vehicles known as vacuum trucks. they pump the septage out of the tank, and transport it to a local fecal sludge treatment plant. it can also be used by farmers for fertilizer, or stored in large septage waste storage facilities for later treatment or use on crops. the term "septage" has been used in the united states since at least 1992. it has also been used in projects by the united states agency for international development in asia. another definition of septage is: "a historical term to define sludge removed from septic tanks." in india some government policy documents are using the term fssm for "fecal sludge and septage management". purposes and benefits lack of fecal sludge management: discharge of fecal sludge into the environment in burkina faso example of lacking fecal sludge management: fecal sludge collected from pit latrines is dumped into a river at the korogocho slum in nairobi, kenya. the overall goal of fsm is the protection of public and environmental health. fsm forms a key component of city-wide inclusive sanitation (cwis), which considers all types of sanitation technologies in order to provide equitable, safe, and sustainable sanitation for everyone.: 2 cwis employs a service delivery approach along the entire service chain, rather than just infrastructure provision. adequately and safely managed fecal sludge has the following benefits: reduce the potential for human contact with fecal-borne pathogens by improving the functioning of onsite sanitation systems; minimize odors and nuisances, and the uncontrolled discharge of organic matter from overflowing tanks or pits; reduce indiscriminate disposal of collected fecal sludge; production and sale of the end-products of the sludge treatment process. these products may include recycled water for agriculture and industry, soil conditioners from composting or co-composting materials, and energy products such as biogas, biodiesel, charcoal pellets, industrial powdered fuel, or electricity. stimulate economic development, and job creation and livelihood opportunities, while addressing the issues of the social stigma and operator health and safety that continue to impact informal workers. this can also include jobs for contractors and equipment installers; for sanitation workers such as sludge collection personnel including drivers and emptiers; and for treatment and reuse systems operators. developments in the sector since the wider recognition of the importance of sanitation, marked by the un declaring 2008 as the ‘year of sanitation’, there has been a steady increase in commitment, uptake, implementation, and knowledge generation in non-sewered sanitation.: 2 the incorporation of the entire sanitation management service chain in the sustainable development goal (sdg) 6, as opposed to just providing access to toilets, has further established acknowledge of the importance of fsm. the sdgs were launched in 2015, and sdg 6 is for "clean water and sanitation for all by 2030"), launched in 2015, has further established acknowledgement of its importance.: 2 there has also been an increase in the incorporation of fecal sludge management in national regulations and development agency agendas, increased funding from foundations and governments, and implementation of infrastructure and service provision.: 2 there has been a rapid increase in evidence-based research and journal publications on the topic (e.g. for africa and asia). there are rapidly evolving technology developments along the entire service chain. some have the potential to alter the existing service chain, such as container-based sanitation, decentralized options, and innovations developed through the bill & melinda gates foundation ‘reinvent the toilet challenge’ since at least 2012. curriculums have been, and are continuing to be, developed and implemented. initiatives include the global sanitation graduate school, and freely available online courses, such as the sandec mooc series. challenges in many lmics, fecal sludge is still not properly managed. this may be due to a lack of mandated institutions and low awareness of the impact of poor sanitation; a lack of technical expertise and experience; an inability to source funds for to purchase of vacuum trucks and treatment, as well as a lack of knowledge necessary to initiate and implement successful fsm programs. this can result in the poor performance of onsite sanitation facilities (ossfs), fecal sludge overflowing from containments, and the unsafe emptying and dumping of untreated fecal sludge into the environment. fecal sludge contains pathogens, can generate odors and cause surface water pollution, as well as groundwater pollution. desludging using proper personal protective equipment in dumaguete, philippines components fecal sludge management (fsm) requires safe and hygienic septic tank and pit latrine emptying services, along with the effective treatment of solids and liquids and the reuse of treated produce where possible. it may include a range of options including on-site and offsite treatment, and the dispersal or capture and further processing of the products of the treatment process into such as biogas, compost and energy. cities fleet of vacuum trucks used for desludging services by manila water in manila, philippines fsm is a critical sanitation service in cities and towns in all countries where households use onsite sanitation systems. citywide fsm programs may utilize multiple or one treatment facility, use stationary and mobile transfer stations, and engage with micro, small and medium-sized enterprises that may conduct some or all of the services.: 99 programs may be phased in over time to accommodate growing demand. peri urban areas peri urban areas are often less densely populated than urban centers. therefore, they have more space and on-site sanitation systems can be effective for solid and liquid treatment. in most such peri-urban areas, it is less likely that they will be connected to a conventional centralized sewerage system in the short or medium term. therefore, these areas will rely on a mix of onsite-sanitation systems and services, decentralized wastewater management systems, or by condominial or simplified sewerage connected to decentralized or centralized treatment. in all of these situations, fsm is a necessary service to keep the sanitation systems functioning properly. rural areas bad practice example: a worker removing fecal sludge out of the pit of a pit latrine without wearing any personal protective equipment (in a village in burkina faso) rural areas with low population density may not need formal fsm services if the local practice is to cover and rebuild latrines when they fill up. however, if this is not possible, rural areas often lack treatment facilities within a reasonable (say 30 minutes drive) distance; are difficult for tankers to access and often have limited demand for emptying making transport and treatment uneconomic, and unaffordable for most people. therefore, options such as relocating latrines on-site, double (alternating) pit or arborloo toilets could be considered. also sharing decentralized fsm services and sludge treatment between nearby villages, or direct safe removal burial of waste could be considered and organized. alternatives to fecal sludge producing systems most types of dry toilets (except for pit latrines) do not generate fecal sludge but generate instead dried feces (in the case of urine-diverting dry toilets) or compost (in the case of composting toilets). for example, in the case of arborloo toilets, nothing is ever extracted from the pit and, instead, the lightweight outhouse superstructure is moved to another shallow hole and a tree is planted on top of the filled hole. management aspects selecting the operator of fsm services fsm services are usually provided by formal and informal private sector service providers, local governments, water authorities and utilities. water utilities with a high percentage of water connectivity (homes with piped water connections) are logical operators of fsm programs. if water is sold to customers through a tariff, an additional tariff to cover fsm services may be added. for larger cities, it is usually the water and sewerage service provider that will be the most appropriate operator. local governments may choose to provide services