Social Relationships and Material Flow in the Co-Creation of Sanitation Systems

Abstract

This chapter describes the challenges of co-creating sanitation system design based on material flow and social network with value flow in urban slums in Indonesia. The challenges are described in three phases: first, to understand and describe the current material flow of sanitation and environment; second, to extend our understanding of the wider meaning of material flow and value flow network; and, third, to evolve the solution through a co-creation process with local players. Through the first phase, we could understand the overall problem of sanitation in the research field by applying material flow analysis; the strength was the ability to catch all the related processes based on a logical mass balance point of view. However, its weakness was too strict rule and it is difficult to describe each player’s motivation; in other words, “driving force” of the system. Therefore, in the second phase, we applied social relationship analysis and could draw reasonable picture of sanitation value flow network. Based on that picture, we had started co-creation approach in order to create new sanitation system with local players, and it is still ongoing. We found that the combination of material flow and social relationship provides reasonable and effective picture of wholistic sanitation system; also, that it is important to validate and update the picture through co-creation process among a team consisting of not only various researchers but also local players.

1 Introduction

When examining materials or substances, material flow analysis becomes a helpful way to understand and explain the sanitation system (Aramaki and Thuy 2010; Harada et al. 2010). However, the sanitation system cannot be explained only by material flow. One of the most important elements to be added to the discussion is the driving force behind the system. In primitive sanitation, the driving force for sanitation material flow is mainly nature. For example, in open defecation in rivers, excreta flows downstream and is degraded by fish, benthos, bacteria, and so on. However, the modern sanitation system was designed based on simplified material flow and the driving force is usually set in a public service system (Ushijima et al. 2015). Therefore, modern sanitation systems work in public service schemes. Generally, it does not work well outside of public service, such as in slums or in low- and middle-income countries where public service is immature. To achieve the Sustainable Development Goals (SDGs), stating “no one left behind,” a new approach for sanitation system design is necessary.

This chapter describes the challenges faced in co-creating sanitation system design based on material flow and social network with value flow in an urban slum in Indonesia. Co-creating new sanitation system is not easy to complete because material flow, social network, and our concerning would be very dynamic. So our challenges are also continuing in this moment. Until now, our challenges can be described in three phases: first, understanding and describing the current material flow of sanitation and the environment; second, extending our understanding to the wider meaning of material flow and value flow network from a solution-oriented viewpoint; third, to evolve the solution through a co-creation process with local players.

2 Background

2.1 Related Project

The trials described in this chapter were conducted from 2004 to 2019 in several projects: Core Research for Evolutional Science and Technology (CREST) headed by Prof. Funamizu and supported by the Japan Science and Technology Agency (JST; 2004–2007); KAKEN type S headed by Prof. Funamizu and supported by the Japan Society for the Promotion of Science (JSPS; 2009–2013), the Toyota Foundation project (2015–2016) headed by Dr. Ushijima, the first author of this chapter; and the full research project in the Research Institute for Humanity and Nature (RIHN; 2016–2022) headed by Prof. Funamizu (2016–2017) and Prof. Yamauchi (2018–2022). The first project, CREST, was a science and technology project; therefore, project members were mainly engineering and agro-science researchers. In the second project, JSPS-KAKEN Type S, there were two fields—Burkina Faso and Indonesia—and various specialists, not only of engineering and agriculture but also social science. In the RIHN project, there were a variety of specialties including human ecologists, health scientists, anthropologists, economists, and engineers.

2.2 Overview of Research Field

Our various field activities since 2004 have been implemented mostly in one specific Rukung Warga (hereafter, “targeted RW”)¹ in Kiaracondong subdistrict of Bandung City, Indonesia. Bandung City is located in the inland part of west Java Island and upstream of the Citarum River, a major water source for the capital, Jakarta flows through (Fig. 13.1a, b). Bandung City and surrounding cities form the Bandung metropolitan, the second largest metropolitan in Indonesia. The population of Bandung City is 2.48 million (Badan Pusat Statistik [BPS] Kota Bandung 2020: 51) and that of Kiaracondong subdistrict with the area of 6.1 km² is 130,080 (BPS Kota Bandung 2020: 9, 51). Kiaracondong is known as one of the biggest urban slums in Bandung City, and the major problems in this area are crowded housing (Fig. 13.2), a high population density, and poor water and sanitation infrastructure; however, the area of informal settlements is limited and most residences are owned or rented legally.

Fig. 13.1

Location of studied area (Ushijima et al. 2008a)

Fig. 13.2

Crowded housing in the targeted RW. (Photo by Ushijima)

Our field activities introduced in this chapter were implemented from 2004 to 2019. During these 15 years, the population in Kiaracondong increased by 3.6%, while the population of Bandung City and Indonesia increased by 5.5% and 23.9%, respectively (BPS Kota Bandung 2005: 116–119, 2020: 51). According to local statistics,² the population of targeted RW was 1477 with 410 households in 2004 and 1291 with 385 households in 2016.

3 First Phase: Identifying Sanitation Issue by Simplified and Partial Material Flow

In the first phase corresponding to the CREST project (2004–2007), we focused mainly on water pollution caused by inappropriate sanitation system. Therefore, a field survey was conducted in and around the Jondol Canal, which flows just beside the targeted RW (Fig. 13.1b). The canal flows into the Cicadas River, a tributary of the Citarum River, which is one of the water sources of capital Jakarta. No houses in Kiaracondong were connected to sewerage systems with treatment plants as of 2019, and the water through the Jondol Canal was apparently polluted by wastewater. The project members, including the authors, tried to quantitatively estimate the effect of pollutant load from the slum by measuring the volume and water quality of daily water use in the catchment area, of wastewater discharge from households in the catchment area, and of water flowing the Jondol Canal.

3.1 Survey on Sanitation Condition in Catchment Area

3.1.1 Overview of Sanitation Condition

According to the local statistics of targeted RW in 2004, the water supply coverage is 21%. Families without water supply obtained water from shared water tap called “CORSEN.” This shared water tap is managed by individual owners, and people pay him/her and take water into a plastic tank or bucket by themselves. People also can buy water from water vendors who carry around ten plastic tanks in a cart (Fig. 13.3). The water vendors buy water from CORSEN and carry it to sell to the aged or families who reside far away from CORSEN. Many wells also exist, which people use for water; however, they do not use them for drinking and cooking due to too much iron contain and contamination by E. coli (Sintawardani et al. 2005).

Fig. 13.3

Water vendor. (Photo by Ushijima)

Regarding toilets, 87% of the households had private toilets and the others used shared toilets, according to local statistics³ in 2004. A typical type of Indonesian toilet is a pour-flush-type squatting toilet (Kurasawa 2001: 107–108). The observed domestic toilets were basically the same; however, some had only steps without a bowl and some toilets only had a hole (Fig. 13.4). Other than household toilets, there were some shared toilets located beside the Jondol Canal or ditch and their wastewater was directly discharged (Fig. 13.5). Some of these toilets were constructed by the residents and some by the local government. The quality of construction is rather low compared to private toilets; however, they are sufficiently clean inside because the users pour water after use. Our observation and interview results indicated that people in targeted RW usually clean their anus or urethral opening with water after defecation or urination. They use a 1- to 2-L pail to pick up water from bucket or tank. This pail is used for flushing the toilet as well as bathing. The toilet and bathroom were not separate in most homes.

Fig. 13.4

Toilet in targeted RW. (Photo by Ushijima)

Fig. 13.5

Shared toilet along Jondol Canal. (Photo by Ushijima)

3.1.2 Interview Survey

Sixty-two families in targeted RW were interviewed in 2005 in order to know about water use, wastewater disposal, and other related matters (Ushijima 2007). Income levels of those respondents were rather low, the average per capita income was approximately 300,000 Rupiah/month, and the mode was 100,000–199,000 Rupiah/month (Fig. 13.6) (Ushijima et al. 2008a, b).

Fig. 13.6

Income range distribution of study area (N = 62 families; Ushijima et al. 2008b)

Figure 13.7 shows the summary regarding water use time for three purposes: “defecation,” “bath,” and “wash.” Large peak was observed in the morning on all three water uses, and small peak was observed in the early evening on “bath” and “wash.” The total volume of these waters corresponds to 55% of the total water usage (Fig. 13.8). Water use for other purposes than the above three was not showing apparent peak.

Fig. 13.7

Time distribution of defecation, bathing, and washing (Ushijima et al. 2008a)

Fig. 13.8

Water usage for each purpose (Ushijima et al. 2008a)

In 53% of the responding families’ homes, wastewater from the toilet or bathing activities was directly discharged into the Jondol Canal and finally flow into the Citarum River. In the remaining 47%, the wastewater was treated using a septic tank. The treatment efficiency of septic tanks is generally low (United States Environmental Protection Agency 2002); furthermore, periodical sludge removal was not conducted in many cases. In this study, we interviewed a worker involved in sludge removal in this area and found that all the removed sludge was thrown into the canals. Wastewater, except that from toilet usage and bathing, was directly discharged from all respondent houses.

3.2 Field Measurement and Mass Balance Analysis

3.2.1 Measurement in the Jondol Canal

Figure 13.1c shows the measurement locations and catchment of the studied section of the Jondol Canal, with a distance of 960 m between the two observation sites. This area of the catchment was 0.41 km² and estimated to have a population of 16,240 and 3585 households. The catchment area is occupied by houses and small farms; factories or other large facilities are not included in this area. Therefore, the side inflow to the canal appears to contain only domestic wastewater and natural components such as rainfall. Our objective was to discuss the effect of domestic wastewater on river water. Hence, our observations were conducted at the end of the dry season to avoid the unsteady effect of rainfall. Regarding other components, there is considerable water usage before prayers in Islamic society. We will discuss this “religious component” in the next section. Feces and urine are the key sources of pollutants; hence, we measured them independently.

3.2.2 Domestic Wastewater Measurement

Regarding households, we observed three cases, as shown in Table 13.1. All the houses were facing the Jondol Canal and the outlet pipes directly protruded from the canal wall. We placed a large bucket just below the pipe (Fig. 13.9). The measurement and sampling were conducted using this bucket at 1-h intervals for 24 h. The sampled water was analyzed using a portable water quality analyzer (Lambda 8022; Kyoritsu Chemical-Check Lab. Corp.). These samples were analyzed as composite sample weighted by amount, except for “single household.” The analyzed items were NH₄–N, NO₂–N, NO₃–N, PO₄–P and chemical oxygen demand (COD) by the indophenol method, naphthylethylenediamine method, naphthylethylenediamine method with deoxidization, molybdenum blue method, and alkaline potassium permanganate method, respectively.

Table 13.1 Wastewater observed families

Fig. 13.9

Domestic wastewater measurement (Ushijima et al. 2008a)

Figure 13.10 shows the per capita domestic wastewater measurement results. A common trend of increased water usage was observed in the mornings and evenings, same as the result of Fig. 13.6. However, several peaks other than morning and evening were also observed, for example, around noon in the “single household” and the “four-person household” and late evening in the “four-person household.” Those peaks seemed due to uniqueness of water use in each household or irregular use, such as because water was used for washing the motorcycle in the late night.

Fig. 13.10

Time series of water usage per capita (Ushijima et al. 2008a)

3.2.3 Mass Balance Analysis Between Domestic Wastewater and Jondol Canal

Mass balance analysis provides basic information about water flow in the targeted area and becomes validation to check if there is missing component to be observed. Table 13.2 shows the integrated results of the water balance, which (a) is the per day flow increment between two observatories and (b) is the estimated total generation of domestic wastewater. The latter was estimated by multiplying each result of the measurement or interview survey with the catchment population. The value of (b)-i to (b)-iv ranges 750–1804 m³/day and those correspond to 29–70% of (a). River system, even if small channel like Jondol Canal, must have natural inflow component, but it is generally difficult to estimate precisely. We assumed that the minimum flow rate in our observation period was the nearest value to the natural component. It was 725 m³/day, 28% of (a). Thus, household water discharge (29–70%) and natural inflow (28%) were apparently major components, and those two occupied in total 57–98% of (a). It means that there might be a missing component with 2–43% of (a).

Table 13.2 Integrated results of the water balance (Ushijima et al. 2008a)

As a probable another component, we focused on water for Wudu.⁴ In Kiaracondong, where 97% of the population (15,753) believe in Islam, water for Wudu could not be ignored. We measured water at one mosque after installing a flow meter on the pipe for water supply, and the water usage was estimated to be 4.7 L/prayer/capita. The total amount of water for Wudu in the catchment was estimated to be 370 m³/day. This activity must be held both at home and in the mosque; therefore, it seemed to be partially included in (b)-ii, (b)-iii, and (b)-iv. Only (c)-i excludes this activity since “water for Wudu” was not an item in the interview survey. When we add Wudu component to (b)-i and (c), total amount reaches 98% of (a). Thus, the water balance estimated above seemed reasonable to explain the situation of study site.

3.2.4 Pollutant Load Balance

Figure 13.11b shows the time series of the net pollutant flux, which was derived as follows: the concentration and flow rate are multiplied with each other and are integrated over an hour; finally, the upstream flux is deducted from the downstream flux for each hour. The results show a pattern similar to that of the concentration (Fig. 13.11a).

Fig. 13.11

Water quality and flux increment in Jondol Canal (Ushijima et al. 2008a)

Table 13.2(b) shows the pollutant load of the domestic wastewater per capita per day estimated from the results of domestic wastewater measurement. As reference data, the reported values of the case in England (Almeida et al. 1999) and Japan (Nakanishi and Domestic Wastewater Treatment Guidebook Editorial Committee 1986: 31) are shown. The values obtained by the different methods are presented in parentheses. The estimated values for the three families varied greatly. Therefore, we focused on the “single household,” which was the closest to the typical condition based on the discussion of water volume. Although the pollutant load from the “single household” was larger than the other two families regarding every item, they were roughly the same as that of the reference data with the exception of NH₄–N. Regarding the amount of NH₄–N, it was probable that NH₄ was generated by the degradation of urea. We should have measured it along with the total nitrogen content; however, we could not do it because of the limitations of our research resources (equipment, time, and workforce).

Table 13.3(a) shows the estimated pollutant flux in the canal; this value was converted to per capita per day. By utilizing the data of the “single household,” the runoff rate was estimated to be 0.7, 0.4, and 0.4 for NH₄–N, PO₄–P, and COD, respectively.

Table 13.3 Estimated pollutant flux per capita per day (Ushijima et al. 2008a)

3.2.5 Contribution of Human Excrements

Table 13.3(c) shows the pollutant load by excrement per capita per day. This was estimated from the excrement analysis. Regarding the feces, almost all respondents (96%) reported the frequency of defecation to be once a day in the abovementioned interview survey. Therefore, we regarded the average weight of the feces sample (90.3 g) as the daily amount of defecation. As for urine, there were no actual data on the urine amount in the area. We considered 1.2 L/day/capita as a reasonable average, as reported by Franceys et al. (1992: 32). In comparison to the reference data, as shown in Table 13.3(b), the estimated values were in a range similar to that of the reference data.

Based on our analysis of the canal water that included only the dissolved part, we estimated the contribution rate of pollutant load by urine in domestic wastewater. The contributions of NH₄–N, PO₄–P, and COD were estimated at 16%, 44%, and 31%, respectively. As for NH₄–N, the actual contribution was larger because of the additional NH₄–N from the degradation of urea in urine, as mentioned above. Furthermore, in the actual situation, the feces also seemed to release soluble pollutants while flowing. This part is not included the estimation above. Thus, the contribution of excrement to domestic wastewater was considerable and it considerably affected the water quality of the Jondol Canal. The improvement of the sanitation system appears to be a high-priority issue concerning the water environment and hygiene.

3.3 Identified Sanitation Issues

According to our field measurement and analysis, we found that a large portion of the pollutant load comes from domestic wastewater. Pollutants from excreta were a measurable part of the domestic wastewater and were assumed to have considerable influence on the river environment. Through this first phase, we found that the improvement of sanitation systems in slums is of vital importance to the water environment; however, we also found structural issue that slum residents are difficult to have motivation to improve their sanitation system. As seen in the field, the private toilet itself is comfortable because people frequently flush and wash the floor; therefore, most of the toilets we saw in the field looked sufficiently clean. People are motivated to flush and wash to keep their toilet; but there is little motivation to prevent discharging their excreta to the river because their efforts to prevent may not feedback them directly.

Although the current sanitation system is apparently problematic for environment, it seems to be a reasonable choice for individual user. Therefore, a more attractive alternative should be provided; otherwise, it is difficult to request people to stop discharging their wastewater. In most urban areas in low- and middle-income countries, public services have been supplementing the rest of the material flow, such as the sewerage system. However, sewerage management cost is now a serious issue in many countries. Furthermore, concerning sustainability, low-cost or value-generating sanitation systems, such as resource-oriented sanitation systems, have become prospective alternatives. The critical weakness of those low-cost resource-oriented sanitation system seems immatureness of the reasonable social system design. In other words, it is desired to create that well-designed material and value flow, which enable better material flow and motivate each actor to join and work for it.

4 Second Phase: Composing Solution Framework by Material Flow and Social Relationship Network

The second phase of our trial took a very long time. It covers the project of late CREST (2004–2007), JSPS-KAKEN (2009–2013), and Toyota Foundation (2015–2016). In this phase, we hypothesized about material and value flow on the basis of the current material and value flow analysis. Then, field research was conducted on candidate players of new material flows and value flows; in other words, sanitation value networks or social relationship networks.

4.1 Crude Picture of Sanitation-Related Material and Value Flow

It is difficult to judge whether a resource-oriented sanitation system with a composting toilet is the best choice or not; however, we had started considering and designing sanitation material flow using the composting toilet system as one of the promising systems. As a first step, a crude picture was drawn (Fig. 13.12). Through this drawing process, we understood that compost collection, transportation systems, and collaborative farmers and their market become essential factors for driving the system. Concurrently, we had already worked in the field (the first phase); therefore, we were exploring available or adaptable material flow that already exists, because creating new material flow seemed much more difficult than adopting currently existing similar material flow.

Fig. 13.12

Crude concept for the new sanitation system

4.2 Possibly Adaptable Material and Value Flow

4.2.1 Garbage Collection System

Regarding compost collection and transportation systems, we focused on the garbage collection system since the early stage of the second phase, around 2006. Indonesia has a unique garbage collection system; each neighbor association (RW) employs a garbage collector by collecting small amounts of money from residents (Unisuga and Watanabe 2004). The garbage collector uses a handcart (Fig. 13.13) to collect garbage from each house and brings it to the middle station (Tempat Penampungan Sampah; TPS), where municipality prepared for garbage transship from handcart to truck. Garbage is loaded on the truck and transported to the dump site (Fig. 13.14). Thus, the garbage collection process from each house to the TPS was managed in a self-help system by residents, and we regarded it applicable to compost collection.

Fig. 13.13

Handcart for garbage collection (Ushijima et al. 2008a)

Fig. 13.14

Garbage transportation by truck. (Photo by Ushijima)

We conducted a survey on the material and value flow of solid waste management in 2006 and 2012. Interview surveys and measurements were combined to understand the reality of the system.

The targeted RW in Kiaracondong employed one worker for garbage collection. People directly hand garbage to the collector or put it in front of their house. The shape of the collector’s handcart (700 × 1150 × 1550 mm) is well-designed as it is suitable for narrow streets in the slum, with a capacity of 1.3 m³. Collection was performed three times per week, and the collected amount per collection day always corresponded to two handcarts. Collection commenced in the morning and sometimes continued into the afternoon. The garbage collector of this community was paid 400,000 Rupiah/month.⁵ Money for garbage collectors, including maintenance costs for handcarts, etc., was collected by the community from each household. The basic price was 2000 Rupiah/month/household, and some extra charge depends on income; however, the extra charging rule was not clear and was not applied strictly.

Garbage amounts from 62 households in the targeted RW were measured in 2006. The total amount was 184 g/day/capita in which 75% was organic waste on average. Table 13.4 summarizes the results of garbage material flow and value flow. Statistical data for Bandung City and other reported values are also shown as a reference. The total amount per capita was estimated by dividing the collecting amount in volume. The total amount is almost half of reference value. The difference may reflect the gap of income level. The reference value is the average of Bandung City, while our target was slum residents’ generally income level was lower. The percentage of organic waste was as well as that of the reference data. The collection capacity of garbage collector was smaller than that of the reference. Because the collector in the area works only 3 days per week and only in the morning, it could be assumed that he had a potential to collect more in a day. The collection fee was smaller than the reference data reported in Asia and Latin America, and the percentage of collection fee in income is much smaller than the reference data reported as general affordability to pay (ATP; Japan International Cooperation Agency [JICA] 2002). Of course, ATP can change by country, community, income level, and so on; however, at least, the present fee seems not to be too expensive for people.

Table 13.4 Summary of field survey on garbage in targeted RW (Ushijima et al. 2008b)

4.2.2 Water Vendors

Among several types of toilets for resource-oriented sanitation system, we assumed urine-diverted composting toilet because the size of this toilet unit is smaller than other types and it will be suitable for slum residents. In terms of material flow, the urine-diverted toilets require collection of solid compost and liquid urine. When we design sanitation material and value flow based on current garbage material and value flow, only a liquid material flow has been lacking. For collecting liquid, we focused on “20L plastic tank” and “handcart” to transport drinking water that residents use in their daily life and water vender, described in Sect. 13.3. The handcart can bring 8–12 tanks. Regarding the salary of liquid collector, we have not yet obtained reasonable value; therefore, we assumed that liquid collector also works for the same salary as the garbage collector, in the cost estimation described later.

4.2.3 Truck Transportation

Referring to the garbage collection system, we assumed that the collected compost and liquid would be transported by a truck. Near the big market in Indonesia, there are truck-waiting areas, where people can find and hire the truck to transport their goods bought in the market. We had interviewed those truck drivers to obtain basic information of their business and cost. Some truck drivers are employed by the company and some are self-employed. The trucks waiting for customers had a wide variety of capacities. They were usually transporting food such as vegetables or fruits, but one of the interviewed drivers had experience in transporting livestock manure compost.

4.2.4 Linkage to Agriculture

To explore linkage to agriculture, we interviewed managers of tea plantations, rubber plantations, and organic vegetable farms and farmers of pineapple farms, flower farms, and rice farms. We tried to understand the material and value flow of those farmers. This research activity was conducted from 2010 to 2019. Results of those research did not provide definite findings nor conclusions; however, they helped researchers to explore possible linkage of sanitation and agriculture via both qualitative and quantitative evaluation. Furthermore, those field research activities provided us a human network and took an important role in the co-creating process, described in Sect. 13.5.

4.3 Feasibility Assessment

At that point of phase 2, researchers have not yet shifted to the idea of co-creation with local people and considered that researchers should propose attractive and affordable sanitation system that gives sufficient incentive for people. Therefore, researchers considered that visualized picture of sanitation value network became useful tool for designing the sanitation system into an attractive and affordable one for people. However, this approach forced researchers to tackle with the issue of assessing the people’s possible acceptance. In order to measure how attractive and affordable the new system is, acceptance by people was usually evaluated somehow; however, it was difficult for local people to imagine and evaluate if the system was completely new and not yet existed. Therefore, as a preliminary step, researchers tried to check the objective feasibility of their concept of new sanitation value flow by utilizing the results of field researches provided in Sect. 13.4.2. In this process, researchers focused on physical feasibility in terms of capacity of collection and transportation, potential demand–supply balance, and economic feasibility.

By separating the evaluation of objective feasibility, researchers found that field trial of the sanitation system with local players would be necessary to evaluate people’s acceptance. This idea had led them to the co-creation concept.

4.3.1 Feasibility of Collection and Transportation Capacity

If we consider a new sanitation system based on crude concept shown in Fig. 13.12, collection and transportation design of compost from toilet and stored urine become necessary. Here, we assume composting toilet that uses sawdust as a composting matrix and needs to add new sawdust after compost removal; therefore, supply and deliver design of new sawdust to replace with compost also becomes necessary. We assumed the frequency and volume of removing compost and adding new sawdust as twice in a year and 0.025 m³ at one time, following the specifications of the commercial composting toilet. The average household size was assumed to be four persons/household based on the real average household size of 3.6 person/household in local statistics of the targeted RW. In this case, replacing the amount of compost with new sawdust will be 0.1 m³/household/time. If all 410 households in the targeted RW use composting toilets and replace compost with new sawdust matrix twice per year, the total amount will be 82 m³/year. If collection frequency was assumed to be three times/week, the required collection capacity will be 0.52 m³ per collection day; this is less than half of observed garbage collection capacity (see Table 13.3). The working condition of the garbage collector we interviewed was that he was working 2 days a week and working time is usually only in the morning; therefore, it seems possible to collect compost in terms of collection capacity. As a related issue, we have to consider the required time for compost removal from composting chamber; it greatly depends on the design of mixing device in composting chamber. If we assume composting chamber with removable screw or removable chamber (see Sect. 13.5.2), additional working time for collection would be only a few minutes per one toilet. However, if the composting chamber equips unremovable screw, from our experience, compost removal takes more than 30 min per one toilet; it may become bottleneck of the system.

Regarding urine collection, in a four-person household, one 20-L tank becomes full after about 5 days. Therefore, 410 households in the target RW will produce 102 tanks per day in total. If we assume that the urine collector can collect three carts per day and that one cart carries ten tanks, 3–4 workers are required.

Regarding the collection cost, it corresponds to the salary of compost collectors; there is no assurance that the community can employ compost collectors with the same salary as the garbage collector. However, according to interview results with three garbage collectors, they gave their consent to work as compost collectors and receive the same salary since there was a need for more jobs. Further, one of them mentioned that compost collection seems to have a lower risk of injury (e.g., glass or needles) than garbage collection.

4.3.2 Feasibility of Demand and Supply Balance

The balance of fertilizer demand and supply is fundamental to evaluate the feasibility of the resource-oriented sanitation system. From the point of view to complement nitrogen on the field, we regarded total nitrogen contained in annual human excreta production in each area for confirming the potential of its supply. This was estimated by multiplying the population and unit value of nitrogen excretion from the human body (Ushijima et al. 2013). We also regarded the annual total consumption of nitrogen in fertilizer as the potential demand. This was estimated by multiplying standard fertilizer use (FAO 2005) and cultivation area (data sources are listed in Table 13.5) for each product. These were analyzed at the district level in the Indonesian language.

Table 13.5 List of agricultural data sources

Figure 13.15 shows the potential balance of demand and supply of excreta fertilizer in each district. Bandung City and some surrounding districts showed supply excess; in contrast, other districts showed demand excess. It is clear that human excreta generated in Bandung City cannot be consumed all in Bandung City and transportation from inside of Bandung City to outside is necessary. Figure 13.16 shows the accumulated demand and supply by distance from Kiaracondong district. This result indicates that the 32 km circle is an indicative area scale that potential demand and supply are balanced.

Fig. 13.15

Potential balance between nitrogen supply and demand in each district. (Reprinted from Sintawardani et al. 2019 with the permission of Springer Nature)

Fig. 13.16

Nitrogen supply potential and demand potential in circle area by its diameter. (Reprinted from Sintawardani et al. 2019 with the permission of Springer Nature)

4.3.3 Feasibility of Economic Aspect

Based on the abovementioned physical and demand–supply assessment, we estimated the basic cost to provide fertilizer from human feces and urine to the farmers in our concept of sanitation system as a baseline of possible lowest price. The assumed cost factors were collection cost from each house, transportation cost from local station to farmland, and a cost for adjusting element balance of fertilizer, mainly adjusting nitrogen phosphorus ratio from the original ratio of excreta to the ratio plants require. The running cost to maintain composting toilet was supposed to be paid by reach household and compost supposed to be given to collector without payment; therefore, those two were not included in the estimation.

We chose one existing tea plantation site as the case site. It is located 47 km from Kiaracondong, which is farther than 32 km that is the threshold distance reversing the balance of potential nitrogen supply and demand. Unit collection costs for urine and feces were estimated by following the scheme described in Sect. 13.4.2. In current garbage collection in the targeted RW, the community collects 820,000 Rupiah/month from households for one collection worker. This cost includes the maintenance cost for their handcart. The assumed concept of sanitation system requires eight collectors for urine collection and one collector for compost collection. Based on this information and assumption, the unit costs for urine and compost collection were estimated at 130 Rupiah/kg for urine and 308 Rupiah/kg for compost.

Unit transportation cost for compost and urine fertilizer was estimated at 154 Rupiah/kg, by price–distance curve (Fig. 13.17), which was obtained by interviews with truck drivers. According to the results of interviews with a tea plantation company, the required amounts of urine and compost were estimated as 7236 kg/ha and 380.7 kg/ha, respectively. These are estimations based on phosphorus demand; an additional 271 kg/ha of urea fertilizer is required to adjust the N/P ratio appropriately.

Fig. 13.17

Price–distance curve of truck transportation. (Reprinted from Sintawardani et al. 2019 with the permission of Springer Nature)

Therefore, the total cost of fertilizer provision in our concept of sanitation system was estimated at 3,318,000 Rupiah/ha. This cost is the same level as the price of synthetic fertilizer: 3,193,000 Rupiah/ha (Fig. 13.18). Thus, the cost for fertilizers produced in our concept seemed to be feasible. However, considering low-income Indonesian farmers can buy synthetic fertilizers at subsidized prices, the price of synthetic fertilizer is less than half, which is impossible to compete for fertilizer from our concept of sanitation systems.

Fig. 13.18

Cost evaluation in the required amount for 1 ha of tea plantation. (Reprinted from Sintawardani et al. 2019 with the permission of Springer Nature)

Thus, the fertilizer provided by our concept has the potential to become competitive in price; however, further cost down is also necessary. According to Fig. 13.18, urine collection and urine transportation costs are a large portion of the cost; therefore, the cost down of this part is desired. From a technical point of view, urine consists of more than 99% of water contents; if we concentrate urine on-site (e.g., evapotranspiration), costs can be decreased.

4.4 The New Sanitation System

Although our feasibility assessment did not completely address all material and value flows, it was surly feasible that compost and urine collection system aligned current garbage collection system. The results are sufficiently convincing to proceed with the next step—a trial of a new sanitation system based on co-creation with players.

We also found that the collection and transportation cost for liquid may become a bottleneck for the system due to their volume and weight. Thus, technological innovation concerning the volume reduction of urine is necessary. Another component of the second-phase trial was to develop a comprehensive picture of material and value flow for the new sanitation system (Figs. 13.19 and 13.20). This picture makes it easy to imagine the new sanitation system; it suggests that it may increase employment opportunities and enhance the local economy.

Fig. 13.19

Current material and value flow in and around the targeted area (Ushijima 2017)

Fig. 13.20

Improved method of material and value flow in and around the targeted area

5 Third Phase: Co-Creating the Sanitation System Considering People’s Social Network

It is difficult to identify exactly when we enter the third phase because the idea of co-creating sanitation system had been gradually practiced in the field of our project, and the concept had been recognized and shared by researchers later. In terms of the period of our project, the RIHN project (2017–2022) was the first project that clearly stated the concept of co-creation. Regarding the co-creation process in our project, we have conducted several trials of co-creation among various researchers and also with local players; some of the trials are still ongoing. In this section, we introduce three of our co-creation trials: authorization from a religious aspect because over 90% of Indonesian people are Muslims; designing an attractive composting toilet for users because the general public’s interests concerned the toilet itself, not the sanitation system; and field test of new sanitation system by organizing field test team with various researchers and local players.

5.1 Authorization from Religious Aspect

Winblad and Simpson-Hébert (2004) proposed to apply faecophobic and faecophilic concepts as personal or cultural response to handling human feces. They said that there are continuum and most cultures are somewhere in-between the extremes. In practical use of this concepts, however, it seems difficult to evaluate the degree of faecophobic or faecophilic, and some studies just mention that Muslim and Hindu cultures are generally faecophobic (Khalid 2018; Nawab et al. 2006). In fact, Islamic rule defines human excreta as dirty material called “Najis,” which must be completely removed from their bodies before praying. Hinduism also defines human excreta as ritually unclean material and needs to be removed. However, we are still not sure it makes sense to evaluate faecophobic and faecophilic, especially in terms of solution.

From the solution-oriented point of view, the important thing is to find and provide good sanitation solution for targeted people, and therefore if there are some religious barriers, how to remove the barriers is the main topic for us. In our research site in Indonesia, in fact, more than 90% were Muslims, and how to commit to Islamic rule is of course a critically important issue, no matter how they are faecophobic or faecophilic. Conversely, we thought that if we obtain religious certification, it will be a big advantage for diffusing the new system.

Thus, we researchers had chosen a way to collaborate with Islamic authorities and co-create the design of new sanitation system with them. As a first step, researchers had approached several major Islamic groups in Indonesia and asked collaboration to check each process of our sanitation concept in the context of Islam, referring to the basic method of building production line for Halal certificated products.

Checking work was done with four religious authorities in Indonesia, Central Majelis Ulama Indonesia (Central MUI), Majelis Ulama Indonesia Jawa Barat (MUI Jawa Barat), Persatuan Islam (PERSIS), and Pesantren Al Quran Babussalam. Majelis Ulama Indonesia (MUI) was established to organize a committee covering all major Islamic groups and key persons in Indonesian Islamic societies (Hosen 2004). This committee discusses and judges the rightness of the habit, which is difficult to judge only by Qur’an and Sunna. The other two, PERSIS and Pesantren Al Quran Babussalam, are two of the major groups in Indonesia and belong to Hanbali school and Shafi’iyah school, respectively.

Researchers had prepared a paper explaining our new sanitation concept and process, and then visited each group’s leader; after explaining the concept and process, they gave a question from below to the leaders and asked to check the system in terms of Islamic rule.

• 1. If some process lets toilet users, collection workers, transportation workers, and other related workers touch feces or urine, is it a problem?

• 2. Is it a problem to store urine and compost in a house?

• 3. Is it a problem to provide compensations for workers who collect urine and feces to users?

• 4. Is it a problem to eat food grown by human feces and urine?

• 5. In this sanitation process, at which point and how the feces and urine change into non-Najis, or never change?

As a result, all Islamic leaders answered they have no problem to questions (1)–(4). Although the reason why they answered so had minor differences: the common points were (1) if the system let someone touch feces or urine, it is not a problem because the washing process is enough to remove the Najis; (2) storage is not a problem; (3) the trade of Najis is prohibited, but paying compensation for collectors’ work is not problem; and (4) eating food grown by human excreta is acceptable. Regarding question (5), all the Islamic leaders finally concluded that our sanitation process is not a problem; however, identifying the exact point when the Najis changed into non-Najis seemed difficult even for them. Two of the four leaders answered that they cannot identify, lest of two mentioned that mixing with soil or biological process make the Najis to non-Najis.

5.2 Designing Attractive Toilet

Although there exist several models of commercial-based composting toilets since more than 20 years, these have not yet been widely used. There are some possible reasons, such as lack of collection and transportation system and lack of market for produced compost, as already described in this chapter. In reality, however, a critically important element for toilet users must be the interface design of composting toilet. To achieve autonomous diffusion of new sanitation systems based on composting toilet, we consider it necessary that we change toilet interfaces and composting systems to be attractive and reasonable. Therefore, we collaborated with product designers in Japan (TAKT PROJECT Inc.) and also with a researcher whose major product design in the Indonesian Institute for Science is to design a composting toilet.

In 2014, our team, consisting of engineering researchers and researchers of product design and product designers, conducted several trials to design a composting toilet. First of all, we asked four Indonesian students who are studying in Japan to simulate their toileting behavior, checked their action, and asked the detail to those students. Based on these results, we designed several trial models and made full-scale mockups of them. Those models are assuming to accept feces, urine, and cleansing water after excretion. By using those mockups, we asked Indonesian people to simulate using those models (Fig. 13.21) and checked in which operation they frequently make misoperation.

Fig. 13.21

Simulated toileting behavior in a mock bathroom. (Photo by Ushijima)

At the same time, we developed a cartridge composting reactor that can collect compost without digging but just by detaching the cartridge (Fig. 13.22) and also developed automatic urine/feces/water separation system. Then we built the first model of composting toilet and again asked Indonesian people, in this case including residents of targeted RW (Fig. 13.23), to simulate using this toilet, then confirmed that most could use it correctly without instructions.

Fig. 13.22

Detachable composting reactor. (Drawn by TAKT PROJECT Inc.)

Fig. 13.23

User test of the first model of composting toilet in Kiaracondong. (Photos provided by Hokkaido University)

The above-described designing process had been conducted mainly by engineering researchers and researchers of product design, but Indonesian researchers also concerned; furthermore, the team discussed with Indonesian people. This process itself also included co-creation aspect.

5.3 Collaboration Among Players in the Field Test

In the RIHN project, the research team named “co-creation team” had been set up and we started consciously taking co-creation approach in Indonesia from 2016 and it is still ongoing. This team is composed of various researchers including engineering, development economy, social psychology, and so on, and aims to co-create sanitation system in the field with local players and to describe the process of co-creation. Through the experience of phase 2, we had known that we need to make a real-scale field trial with local players, which means co-creation approach, in order to proceed to the next step. Therefore, the team planned to (1) organize a field test team with local players, (2) brake down our concept of new sanitation system into practical field test plan, (3) conduct a field test of new sanitation system, (4) draw the revised picture and action plan of new sanitation system and (5) involving further players for new sanitation system.

At that point, we had already developed a relationship with some of the players. Therefore, we started by enhancing our existing relationship with players: Babakan Synar Elementary School in Kiaracondong; garbage-collection-related workers in Kiaracondong; Eco-pesantren, which is an Islamic school, and so on. In addition, we contacted several foliage plant farmers in Lembang village, which has vast agricultural field next to Bandung City for trial of new sanitation system with non-food-producing agriculture. We introduced our new sanitation concept to farmers and farm owners by using visual materials, such as short movie and illustrated toilet tissue (Fig. 13.24). Through this exploration, finally we got three collaborative farmers. We visited the players several times and discussed the new sanitation system with them.

Fig. 13.24

Discussion with players using visuals. (Photos by Ushijima)

Among several collaborative schools, Babakan Synar Elementary School had too few toilets compared to the number of students and desired to increase toilets. Teachers in this school also had a high interest in our project in terms of WASH education. Through the discussions between researchers and school teachers, they agreed to install two composting toilets for our field test in this school and allow students to use those toilets. Through those discussions, researchers found that the person who opens small kiosk in this school was also in charge of cleaning current toilet in this school. Researchers also interviewed and discussed with her, and she agreed to join our field test as a player for cleaning and maintaining composting toilet.

Regarding compost and urine collection, researchers discussed with garbage collector of targeted RW. He had been working as a garbage collector of the RW, and therefore he had already known our research activities from 2004, and he agreed to join the field test as a compost and urine collector. Among three collaborative farmers, one young farmer had especially a strong interest in compost and urine use for his cultivation. He asked many questions to researchers about expected performance of compost and urine fertilizers, and trial plan in his farmland was discussed with researchers.

Through these discussions, researchers and local players drew the field test plan using composting toilet in Babakan Synar Elementary School, collecting compost and urine by present garbage collector, hiring truck to transport compost and urine, and utilizing compost and urine by foliage plants farmers in Lembang. Those discussion processes also enabled researchers to organize a field test team including local players (Fig. 13.25). In August 2019, all the field test team members gathered and a kickoff workshop at Babakan Synar Elementary School was held (Fig. 13.26).

Fig. 13.25

Field test team

Fig. 13.26

Kickoff workshop for the field test team. (Photos by Ikemi)

After that, two composting toilets were installed in Babakan Synar Elementary School and a pretest by limited students was conducted in September 2019. The field test team planned to start field test from the 2020 summer; however, the team could not continue it owing to the COVID-19 pandemic.

5.4 Future Plan for the Third Phase and the Post-Third Phase

The third phase is still ongoing. Although researchers still cannot visit the site owing to the COVID-19 pandemic, Indonesian and Japanese researchers set monthly webinar since June 2020, and keep discussing and exploring the way to restart the field test of new sanitation system. Regarding local players in the field test team, researchers also keep in touch with them via web meeting system or SNS. Thus, we have been trying to keep connection among the team and also been making trial to do co-creation via web connection.

6 Conclusions

This chapter described our challenge of the co-creation, which was conducted through expanding the material flow approach to social relationship networks and developing effective solutions. Through our 15-year process, we found that material flow and social relationships affinitized strongly each other. Through the first phase, we could understand the overall problem of sanitation in the research field by applying material flow analysis; the strength was the ability to catch all the related processes based on a logical mass balance point of view. However, its weakness was too strict rule and it was difficult to describe each player’s motivation; in other words, “driving force” of the system. On the other hand, the strength of social relationship analysis is that it can describe each player’s motivation, and its weakness is that it is difficult to list all related processes or players. Therefore, in the second phase, we applied social relationship analysis based on the result of material flow analysis obtained in the first phase and could draw a reasonable picture of sanitation value flow network. Based on that picture, we had started co-creation approach in order to realize the concept of the new sanitation system with local players, and it is still ongoing.

We found that the combination of material flow and social relationship provides a reasonable and effective picture of wholistic sanitation system, and also that it is important to validate and update the picture through co-creation process among a team consisting of not only various researchers but also local players. Although we have not yet sufficiently performed co-creation of sanitation systems, we found one promising approach. In our case, it took 16 years owing to our trial-and-error process; however, this approach can be adopted at different sites and it will not take a long time to reach co-creation.