by using their own staff and resources for collection, transportation and treatment. this is often the case in smaller cities or municipalities where the water utility may not have a broad reach. in many cases, cooperation between the city government and the water utility may be strategically advantageous. dumaguete city, philippines, is one example where the water district (utility) and local government have joint ownership and responsibilities for the fsm program. organized larger scale fsm programs may be able to provide the service more cheaply and more hygienically than the independent private operators working on an ad hoc basis. ensuring services are affordable is an important selling point when promoting the program to citizens and encouraging them to participate. the local private sector is an important player in providing fsm services. in such cases, private sector contractors may work directly for households (under regulation) or bid on desludging contracts let by the city. the private sector can also provide services in operating and maintaining the treatment works, and in processing and selling the commodities resulting from the treatment process. san fernando city, la union, philippines is an example of a local government that has contracted out the treatment facility construction and collection program to the private sector. scheduled desludging programs scheduled desludging is a planned effort by the local government or utility to ensure regular desludging of septic tanks. in this process, every property is covered along a defined route and the property occupiers are informed in advance about desludging that will take place. the actual desludging (or emptying of septic tanks) can be done through a public private partnership (ppp) arrangement. in southeast asia, there is (in 2016) increasing interest in scheduled desludging programs as a means of providing services. a wsp study recommended that efforts to introduce scheduled emptying should focus first on areas where demand was greatest, moving on to other areas when the success of scheduled emptying had been demonstrated in these areas. analysis of pit and tank desludging records for palu in indonesia revealed that existing demand for desludging services varied between sub-districts, with demand being greatest in well-established areas and least in urban fringe areas. there are multiple benefits of scheduled desludging services in the indian context: achieves the norms through regular desludging, reduces high prices of desludging, removes the need for manual labor, improves environmental and public health impacts, links with local taxes rather than with user charges. scheduled desludging has been initiated in several asian counties including the philippines, malaysia, vietnam, indonesia, and india. a program by snv (netherlands development organisation) has developed scheduled emptying services in indonesia, nepal and bangladesh as part of a broader urban sanitation program during 2014–2017. elements of successful programs desludging truck (vacuum truck) in action in nepal fsm services can be provided as demand based (often called on-request, on-call, on-demand, ad-hoc or non-scheduled) or scheduled (also known as regular) desludging, or a combination of both. under either mechanism, ossfs are desludged on a periodic basis or when the household requests it or due to inspection by a competent authority indicates desludging is needed. an analysis of 20 fsm innovation case studies and research and advocacy of successful programs carried out by oxfam philippines has demonstrated that common elements for successful fsm programs include: well formulated and practical policy, rules and regulation: while these are essential they are almost useless, even counterproductive, on their own, and must be supported by complementary factors such as those below; local leadership and clearly mandated and resourced institutions to manage services, even where actual services are delivered by the private sector; partnerships between stakeholders contributes to developing services at scale, building community confidence and achieving sustainability; a sustained program of community engagement, marketing and awareness raising is as essential to fsm as sludge treatment – but is frequently under-valued, under-budgeted and sometimes abandoned after an initial period; capacity-building for fsm service providers helps ensure that they can effectively meet all segments of demand and achieve long-term viability. this may include training in both technical matters and business management, and the facilitation of capital formation through grants, equipment leasing, loan guarantees and other financial instruments; tariffs that are pro-poor and representative of operational costs for providing the service; technology that is appropriate to the capacity to operate and maintain the system and the realities of the value chain. sanitation workers sanitation workers are the people responsible for cleaning, maintaining, operating, or emptying a sanitation technology at any step of the sanitation chain.: 2 these workers contribute to safe fecal sludge management. this section is an excerpt from sanitation worker. a sanitation worker (or sanitary worker) is a person responsible for cleaning, maintaining, operating, or emptying the equipment or technology at any step of the sanitation chain.: 2 this is the definition used in the narrower sense within the wash sector. more broadly speaking, sanitation workers may also be involved in cleaning streets, parks, public spaces, sewers, stormwater drains, and public toilets. another definition is: "the moment an individual’s waste is outsourced to another, it becomes sanitation work.": 4 some organizations use the term specifically for municipal solid waste collectors, whereas others exclude the workers involved in management of solid waste (rubbish, trash) sector from its definition. transport options collection vehicles and equipment further information: vacuum truck the "gulper", a device for manual pumping of fecal sludge from pits used in durban, south africa if the fecal sludge is liquid enough, it is usually collected by using vacuum pumps or centrifugal style booster pumps. a variety of manual and motorized devices designed to excavate thick and viscous sludge and accumulated trash are also available in the market. after sitting for years in septic tanks and pit latrines, the accumulated sludge becomes hardened and is very difficult to remove. it is still common that workers enter pits in order to desludge them, even though this practice is generally unsafe and undesirable (in india, this practice is called "manual scavenging"). a number of low-cost pumping systems exist to remove this hardened sludge hygienically from the ground surface, although many of them are still in the experimental stage (e.g. excravator, gulper, e-vac). fecal sludge can also be treated inside the tank or pit as well, by use of the "in-pit lime stabilization process", which treats the waste before it is removed from the tank or pit. once removed, it is transported to onsite or off site treatment and processing facilities. some advanced transfer stations and vacuum trucks can dewater fecal sludge to some extent, and this water may be placed in sewer lines to be treated in wastewater treatment plants. this allows more sludge to be dealt with more efficiently and may constitute one of the best cases of co-treatment of fecal sludge in wastewater treatment plants. transfer stations transfer stations are intermediary drop off locations often used where treatment facilities are located too far away from population centers to make direct disposal feasible. in other locations, traffic concerns or local truck bans during daylight hours may make transfer stations feasible. in addition, municipalities where a significant percentage of homes cannot be accessed by tanker truck should utilize transfer stations. transfer stations are used if: more than 5% of the homes are inaccessible by a vacuum truck; the treatment plant is too far away from the homes for transport in one haul to be practical; trucks are not permitted on the streets during the day; or heavy traffic during daylight hours impedes the movement of vacuum trucks. mobile transfer stations mobile transfer stations are nothing more than larger tanker trucks or trailers that are deployed along with small vacuum trucks and motorcycle or hand carts. the smaller vehicles discharge to the larger tanker, which then carries the collected sludge to the treatment plant. these work well in scheduled desludging business models. fixed transfer stations fixed transfer stations are dedicated facilities installed strategically throughout the municipality that serve as drop off locations for collected fecal sludge. they may include a receiving station with screens, a tank for holding the collected waste, trash storage containers, and wash down facilities. these may be more appropriate for fsm programs using the "call-for-service" business model. while static transfer stations are fixed tanks, mobile transfer stations are simply tanker trucks or trailers that work alongside the svvs and actually do the longer haul transferring of the waste from the community to the treatment plant. mobile transfer stations work best for scheduled desludging programs where there are no traffic restrictions or truck bans, and a relatively large number of homes that are inaccessible to the larger vehicles. treatment processes further information: sewage sludge treatment drying bed for emergency fecal sludge treatment by oxfam in the philippines drying bed for fecal sludge in bangladesh characteristics of fecal sludge characteristics of fecal sludge may vary widely due to climate, toilet type, diet and other variables. fecal sludge can be grouped by consistency as "liquid" (total solids or ts <5%), "slurry" (ts 5–15%), "semi-solid" (ts 15–25%), and "solid" (ts >25%).: 3 quantities and qualities of fecal sludge and wastewater are very different, with the range of fecal sludge characteristics being 1–2 orders of magnitude higher than wastewater.: 4 the result of the demographic, environmental, and technical factors that influence characteristics of fecal sludge is a high level of heterogeneity that complicates characterization.: 23 in the absence of actual data, designers often use default values, such as 2,000 mg/l for bod and 5,000 mg/l of tss in order to size the treatment system. however, this often results in over-design or under-design of fecal sludge treatment plants. this is because there is often no "standard range of variation" for particular properties, and findings from one study cannot necessarily be used as a base of comparison to another.: 23 research has shown that correlations to spatially available data can help predict quantities and qualities of fecal sludge. the relevant indicators for the prediction include income level, users, volume, emptying frequency, and truck size. using these correlations in characteristics could provide a way to reduce analytical costs for fecal sludge analysis. performing a waste characterization study helps to understand local conditions and provides data that factors into treatment plant sizing. it can also help to estimate the value of the products that can be derived from the treatment process. the main physico-chemical parameters commonly measured to characterize fecal sludge include: bod, total suspended solids, % solids, indication of sand, cod, ammonium, total nitrogen and total phosphorus, fats, oil and grease (fog), sludge volume index (svi), ph, alkalinity. relatively little data exists on pathogen content in fecal sludge. one study from rural bangladesh determined 41 helminth eggs per g of fecal sludge from pit latrines. the characteristics of fecal sludge may be influenced by: methods, techniques and the skill levels of personnel conducting the desludging; the efficiency of the different types of equipment used in desludging; seasonality – presence of groundwater or flood water that may infiltrate into tanks and dilute the contents; the last time the tank was desludged (age of fecal sludge). conventional treatment processes fecal sludge is often processed through a series of treatment steps to first separate the liquids from the solids, and then treat both the liquid and solid trains while recovering as much of the energy or nutritive value as possible. common processes at fecal sludge treatment plants include: fecal sludge reception – where the truck interfaces with the treatment plant and sludge is unloaded. preliminary treatment – to remove garbage, sand, grit, and fog (fats, oil and grease) primary treatment – simple separation of liquid and solids by physical means (dewatering and thickening), e.g. with drying beds liquids treatment – for example by using constructed wetlands, waste stabilization ponds, anaerobic digesters solids processing – using the solids resulting from fecal sludge treatment for beneficial use where possible. constructed wetlands are gaining attention as a low-cost treatment technology that can be constructed in many instances using local materials and labor. for sites with enough land and a ready supply of gravel and sand, this technology offers low cost, scalability, and simple operation. drying beds simple sludge drying beds can be used for dewatering and drying, as they are a cheap and simple method to dry fecal sludge (they are also widely used to