Urban water systems: Development of micro-level indicators to support integrated policy.

Urban water systems involve complex interactions between ecological, social and economic factors. Integrated management approaches are needed to achieve multiple policy objectives in the sector and can be pursued at a range of spatial scales. Small-scale integrated water projects are both feasible and valuable in dynamic urban environments in developing countries. This paper develops a method for the prioritization of localities for integrated projects and applies this to the city of Jakarta. A set of indicators is defined following a systems approach, populated, displayed through a dashboard and mapped, and the relationships between indicators are analysed. Indicator-based prioritization allows policy-makers to guide resources to integrated projects to contribute effectively to the achievement of policy goals.

1 Introduction

Urban water systems encompass ecological, social and economic factors. Within these systems, natural water resources and ecosystems interlink with infrastructure for water supply, collection and treatment of wastewater and flood protection. These interact with the behavior of people, firms and governments in their use of water for health, recreation, livelihoods and economic activities.

The multi-faceted nature of the urban water system is reflected in the wide-ranging set of policy goals relevant to the sector. This is illustrated by the Sustainable Development Goals (SDGs) for water, which cover access to water supply and sanitation, water pollution, resource conservation, ecosystem restoration and integrated management. Many governments have additional policy objectives relating to flood risk management, energy use, service quality and public participation in decision-making. The interconnections between aspects of the sector imply that interventions designed to meet one policy objective may have unintended positive or negative consequences for the achievement of other objectives.

Urban water systems are subject to increasing uncertainty as a result of rapid urbanization and densification of built-up areas, economic development, changes in climate and interconnections with energy and food systems. Policies and management strategies which were effective in meeting policy goals in the past, like centrally operated distribution and treatment systems, may no longer be able to cope with the scale and dynamic nature of contemporary challenges. These pressures are likely to be even greater in high-growth cities in developing countries where existing infrastructure does not provide universal access to safe water and sanitation.

The design of appropriate interventions to achieve water policy objectives within this complex system requires a system-level approach like that of integrated water resources management (IWRM). IWRM is a well-established framework in the water sector which takes into account both human and ecological needs, and can be defined as “a process which promotes the coordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital eco-systems.” [1]. IWRM is endorsed by many national governments across regions and levels of economic development and at the global level through its inclusion in the SDGs.

At the city level, a range of concepts have been proposed for the application of IWRM principles, including Integrated or Sustainable Urban Water Management (IUWM) [2-6], Total Water Cycle Management [7], Water Sensitive Urban Design or Cities [8,9]. While these concepts have different emphases, they all reflect a shift from traditional, centralised engineering-focused management towards approaches which take into account system-level interlinkages and user preferences [10].

In the context of IUWM, increasing attention is being given to the potential for small-scale distributed systems to complement the centralized network. These can combine water, wastewater and solid waste treatment, reducing network costs and providing economies of scope, such as co-treatment of organic waste and wastewater and the direct use of biogas. Distributed infrastructure may provide greater flexibility to respond to changing conditions, reduce risk and contain the impact of failures, reduce costs associated with transmission and distribution, strengthen local communities and economies and allow for more sensitivity to local conditions and impacts [11-13].

The benefits of distributed systems may be particularly high in cities in developing country cities where urban water systems are highly fragmented in terms of sources, technologies and actors, leading to poor and unequal outcomes [14,15]. Households in these cities are obliged to patch together water supply for different uses from a range of sources, sometimes leading to the unsustainable use of local water resources [10]. However, the failure of existing models in these challenging urban contexts may provide the opportunity and incentives for transitions to integrated water governance and management [16]. Studies in Vietnam and China [15,17] point to significant potential benefits from integrated projects in expanding Asian cities. If designed appropriately, IUWM projects can contribute to multiple policy goals while avoiding unintended effects of policies designed to tackle a single policy objective [18].

Despite the potential benefits, mainstreaming IUWM has often proved challenging [4]. Governance structures and embedded interests can restrict incentives to innovate and the costs of retro-fitting existing systems may be prohibitive, limiting IUWM interventions to distributed systems in new build areas [19]. Further challenges include interactions between decentralised projects and existing centralised infrastructure and whether the projects can be economic and ecologically sustainable in the long-term [18] as well as the limited implementation capacities of the sector [20].

Currently, the selection of sites for IUWM projects is often ad hoc and opportunistic. While the ad hoc approach may sometimes offer advantages, as it is able to capitalize on leadership and community motivation at the micro-level, it is unlikely to be optimal in terms of efficiency or equity when considered from the perspective of the achievement of policy goals. Local interventions need to be aligned and coordinated by a strong strategy at the city level and implemented using consistent methods in order to maximize the contribution of IUWM to meeting policy objectives [21]. An evidence base is needed to inform such a strategy.

The objective of this paper is to develop an evidence base for IUWM strategy for the city of Jakarta, Indonesia, to assist government agencies, utilities and financial institutions in prioritizing projects for funding and monitoring implementation in the context of limited resources. The paper aims to contribute to the growing literature on IUWM and evidence-based approaches to project selection and evaluation through the development of micro-level indicators for the water sector. In policy terms, the paper seeks to support the take-up of IUWM approaches in Indonesia, using Jakarta as a demonstration case, with potential application to other countries.

Jakarta provides an interesting setting within which to study IUWM adoption as a confluence of factors opened a window for a transition to IUWM in Jakarta in the late 2010s. The central government adopted an ambitious target to expand access to safe water supply to 100% by 2024 and the local government set an additional target to expand piped supply to 100% by 2030. However, the local government faces budget constraints and restrictions on raw water availability. Surface waters in Jakarta are highly polluted and efforts to secure additional raw water supplies from outside the city have been unsuccessful; groundwater has been over-exploited, contributing to land subsidence and saltwater intrusion. Local government agencies and the city’s private concessionaires are therefore experimenting with alternative ways to expand supply through IUWM, with the support of the World Bank, the Association of Indonesian Municipal Governments (APEKSI) and the central government.

Within this policy context, this paper develops and analyses a set of micro-level indicators to measure the performance of the urban water system across Jakarta using the frame of water security. The approach and method for the selection and population of the indicators are set out in Section 2. Section 3 introduces the study area in more detail. Section 4 highlights findings on the relationships between indicators which are discussed in Section 5. Section 6 concludes and proposes steps for further research.

2 Approach & method

Our objective is to develop a systematic basis for prioritization of localities for IUWM interventions in Jakarta within the context of highly differentiated performance and dynamic change. Our unit of analysis is the smallest urban administrative jurisdiction in Indonesia, known as “kelurahan” or village, which corresponds to the appropriate scale for local IUWM projects indicated in the literature reviewed.

Our starting point is to develop a set of indicators to measure the current attributes of the water system. We frame performance in terms of water security, which we interpret broadly, following the UN definition of water security as, “The capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability.” [22]. We understand water security as an over-arching policy objective which encompasses objectives articulated in the Sustainable Development Goals as well as the management of flooding and other water-related risks.

We adopt a systems approach to the development of indicators as urban water security is affected by many interrelated mechanisms resulting in a high degree of complexity and the systems approach can help to provide clarity on these interactions and the underlying causal relationships [23-25]. We focus on individual indicators and how they interact in the context of IUWM interventions, using a dashboard approach and calculating a simple unweighted index. Further work could be done to refine this into a composite index by prioritizing indicators and establishing weights through multi-criteria decision analysis (MCDA) [26].

Following the work of van Ginkel et al [27], we employ the Pressure-State-Impact-Response (PSIR) framework to develop indicators. PSIR is a well-established approach for the development of indicators in dynamic environmental systems [28-31] and has been applied to water-related issues [32-35].

In this framework, pressures are factors which influence the state of the system. These are sub-divided into environmental and socioeconomic categories. Environmental pressures include characteristics of the climate and hydrology. Socioeconomic pressures relate to demographics, characteristics of spatial development and economic activity. State refers to the current properties of the system, either natural or built, including infrastructure for the collection and treatment of water and flood protection. We include variables on the extent and quality of network service provision. Impact refers to outcomes understood in terms of the functions of the system, from the point of view of the citizen, reflected in access to safe water and disease incidence, and of the environment, reflected in resource degradation. Responses refer to actions taken by policymakers, firms and households in relation to water services. These are captured through qualitative assessments of water policy and strategy.

Using this framework, we develop a set of indicators. These are summarized in Table 1.

Table 1

Indicators selected for the urban water security index for Jakarta using the PSIR framework.

CODE*	INDICATOR	METRIC	RANGE/SCALE
1000	PRESSURE INDEX
1100	Environmental pressures
1104	Elevation	Elevation above sea-level	-5 to 44m
1200	Socioeconomic pressures
1201	Population growth	Annual population growth	%
1202	Slums	Slum density	%
1203	Economic activity	Night-time light radiance	10 to 120
1204	Non-domestic demand	Water usage of small-medium industries	0–2
1205	Industrial activity	Industrial zones	Binary (0/1)
2000	STATE INDEX
2100	Water Service
2101	Piped water access	Piped water network coverage	%
2102	Piped water pressure	Piped water pressure (percentage of months in a year with low water pressure)	5 categories
2200	Water Quality
2201	Drinking water quality	City-level	-
2202	Groundwater quality	Groundwater conservation zone classification	1 to 3
2300	Infrastructure
2301	Wastewater disposal	Population with access to septic tank	%
2400	Flood protection infrastructure	City-level (qualitative)	-
3000	IMPACT INDEX
3100	Water Supply
3101	Access to safe water	Population using protected water sources	%
3102	Reliance on groundwater	Groundwater consumption (litres per capita per day)	0 to 10
3200	Health
3201	Sanitation access	Population with access to toilet	%
3202	Waterborne disease risk	Diarrhoea prevalence rate (no. of cases per 10,000 people)	0 to 950
3203	Water-related disease risk	Dengue prevalence rate (no. of cases per 10,000 people)	0 to 17
3300	Environment
3301	Groundwater over-exploitation	Change in Groundwater Conservation Zone (2013–2017)	-1 to 1
3302	Flood incidence	Number of years flooded between 2013 to 2016	0 to 4
4000	RESPONSE INDEX	City-level (qualitative)

*Codes are not consecutive as city-level indicators have been excluded from the table.

The indicators were developed iteratively. First, we identified a preliminary set of 54 pressure, state, impact and response indicators based on the framework and literature. 25 of these are measurable only at the city level and not at higher spatial resolution. These city-level indicators are discussed in Section 3. For the purposes of the indicator set, we focus on the 25 indicators for which there is variation between the micro-level administrative units (“kelurahan”) or villages.

The next step was to populate the indicators. The sources of data, units, scaling and additional remarks are provided as supplementary information for the paper. Where possible, we used publicly available data from official government sources. The main sources of data were census data from the national statistical agency (Badan Pusat Statistik, BPS) and data from the Jakarta statistical agency. Data on piped connections per micro area or village were provided by the water utility, Pam Jaya.

Where data were not available, we identified a suitable proxy. For example, micro-level estimates of economic activity are not available from the statistical agencies. We therefore construct a variable based on Night-Time Lights data. A full explanation of the construction of this variable is provided in the supplementary information. For flooding, the publicly available data do not distinguish between riverine, coastal and stormwater flood events so we combined these into a single flood incidence indicator. Where no data were available at the desired spatial scale, we were obliged to drop the indicator from the set. The database format allows for the indicator set to be updated if more information becomes available. Following this process, we were left with a set of 17 indicators.

A dashboard interface for interrogation and display of indicator data was developed in Microsoft Excel. The dashboard approach allows interested parties to compare administrative units on a single dimension or to view data for all indicators for a single administrative unit. The presentation of the data in this accessible format is intended to facilitate its use by decision-makers as well as other researchers. Access to the dashboard is available from the authors on request.

We then transform all the indicators into a 5-point scale and aggregate the total into an unweighted water security score for each administrative unit. This simple method of aggregation weights all constituent indicators equally. Policymakers and other interested parties may wish to apply different weights to the constituent elements, which is facilitated by the dashboard interface. A consistent set of weights for all stakeholders could be established through a MCDA approach.

In October 2019, focus group discussions were conducted in Jakarta, focusing on the identification of suitable IUWM models. Five discussions with 4–8 participants per group were held. Participants were purposively selected to represent central and local government departments responsible for water resource management and water service provision, sector associations and financiers. The focus group findings are reported briefly in Section 6.

3 Study area: Jakarta

This section presents the interlinkages between water resources, infrastructure, policy and governance of the water system in Jakarta. Overall, Jakarta faces a high level of water risk associated with the limited coverage and quality of piped water supply, poor sanitation, pollution of surface water sources, over-abstraction of groundwater, land subsidence and high riverine, pluvial and coastal flood risks.

The special capital region of Jakarta (DKI Jakarta) has a population of 10.64 million. It forms the central part of a larger metro area of more than 30 million people known as Jabodetabek. Jakarta’s population has grown by 27% since 1990 and continues to grow at a rate of around 1.1% a year.

Land elevation falls from south to north, with the most densely built areas of the city found in the downstream area. 13 rivers and 2 canals flow across Jakarta from south to north and have estuaries in the Java sea along a stretch of coastline of approximately 35 km. Jakarta’s average annual rainfall is 1816mm with monthly variation of 43-300mm. There is evidence of increasing rainfall extremes which contributed to very severe floods in 2007 and 2013 [36].

Piped water supply coverage in Jakarta is far from universal. The public water service agency, Pam Jaya, estimated coverage to be 73% in 2017. Of those households which do have a piped connection, many receive intermittent supply: 45% of customers in the western area of the city and 62% in the eastern area have 24-hour service [37]. Water pressure is also highly variable across the city. Less than half the water supplied meets the service standard of 0.75atm [37].

Piped network supply in Jakarta is constrained in part due to the limited availability of raw water. Around 80% of the city’s water supply is drawn from the Jatiluhur Dam in the neighbouring province of Bekasi. The allocation of water from the dam is set under the authority of a state-owned company, PJT2, and the allocation has not been increased since 1997. The allocation is equivalent to less than half the estimated water demand of the city [38]. The quality of water in the dam has declined in recent years and the number of competing users of dam water has risen.

Supplies from Jatiluhur are supplemented by bulk treated water purchased from the neighbouring province of Tangerang. In future, a new dam is planned at Karian in Banten province but the timeframe for this is not certain [39]. Low raw water availability is exacerbated by the poor condition of the water transfer and distribution infrastructure in Jakarta. Non-Revenue Water (NRW) was estimated at 44.16% in 2017 due to physical leaks and unauthorized connections.

Low-income households not connected to the network sometimes buy piped water from neighbours. The per-unit price of purchases from neighbours varies widely, averaging more than six times the cost of piped water through a formal connection [40].

Households at a range of income levels use groundwater for household purposes to supplement or replace piped water. High-rise apartment blocks catering to higher income groups generally draw groundwater from the confined deep aquifer while other households draw water through shallow wells from the unconfined shallow aquifer [37,40]. Domestic use of groundwater from the shallow layer is allowed without a permit (except for ‘affluent households’) and no abstraction fees are payable. Government institutions are also able to use groundwater without a permit or fee. Commercial and industrial users are required by regulations to register borewells and monitor abstractions, but many do not do so. Since 1998, a fee has been imposed for the abstraction of groundwater, but it has been patchily enforced. The northern part of the city area has been designated a zero-abstraction area in which no new deep wells are authorized, yet unauthorized abstraction continues.

Neither piped water nor groundwater is usually potable and households generally rely on bottled water for drinking purposes when they can afford to do so.

Over-withdrawals from the contained aquifer have led to salinization of the shallow subsurface layer [41,42]. Availability and quality of groundwater are expected to worsen further over time [43].

Intensive abstraction of groundwater has also contributed to land subsidence, along with natural consolidation of alluvial soil and settlement of high compressibility soil due to construction [41]. Between 1974 and 2010, land subsidence in Jakarta typically varied from 3–10 cm/year across the city, with cumulative subsidence of 4 metres in some areas over this period. The impact of subsidence is seen in damage to housing, buildings and infrastructure, changes in river canal and drain flow systems, increased inland sea water intrusion and perhaps most significantly, wider and more severe flooding.

Jakarta has a long history of seasonal flooding during monsoons but in recent years flooding appears to have become more frequent and affected larger areas of the city. The floods of 2007 and 2013 were the most destructive recorded. In 2007, 75% of the city was flooded and 430,000 people were displaced. Damage to infrastructure and assets was estimated at US$900 million [44]. In 2013, the breach of the western flood canal dike resulted in 10–20 days of severe flooding in the northern areas of the city, while floods in greater Jakarta in early 2020 led to more than 60 deaths.

Since the floods of 2007, considerable efforts have been made by the Jakarta government to improve flood protection for the city, with the support of the World Bank. The Eastern Banjir (Flood) Canal was constructed and existing canal system has been dredged, renewed and extended [45]. To address coastal flood risk, the national and city governments adopted a master plan in 2014. The first phase, extending and strengthening the current sea wall, has been completed. Subsequent phases which include the construction of an outer sea wall defence, are under evaluation. While these measures have effectively reduced flood risk in some locations in the city in the short-term, risks are expected to rise in the future as a result of sea-level rise, subsidence and ongoing development and land use changes in upstream areas.

Sanitation coverage is extremely limited in Jakarta. Jakarta has only one functional wastewater treatment plant which has a capacity of 22 million litres per day (MLD), capable of treating less than 5% of the wastewater produced by the city [38]. The majority of households have septic tanks for the disposal of wastewater.

The very low level of wastewater collection and treatment has contributed to high levels of contamination in environmental waters and potentially irreversible pollution of surface waters and shallow aquifers [46]. Dsikowitzky [47] estimates that 5–17 tons of pollutants from municipal sources are carried by just one urban river, the Ciliwung, into Jakarta Bay each year. The wide distribution of fecal contamination in Jakarta Bay is also a concern for food safety in aquaculture and local fisheries.

Turning to the policy context, Indonesia is committed to the SDGs. In addition, the national government has set a target of universal coverage to safe water supply by 2024. With development partners, strategies have been developed to increase raw water supply [39] and sanitation [48] but the government has not committed to timelines for implementation.

Currently, governance of the water sector is Jakarta is complex and highly fragmented. Water supply, water resource management, groundwater, wastewater and flood management are all under the responsibility of different government departments. In addition, Indonesia has a decentralised mode of government under which water supply and sanitation are the responsibility of local government. In the case of Jakarta, the responsibility falls on the Governor of DKI Jakarta. A local elected assembly approves budgets and any adjustments in tariffs for water supply.

Since 1998, water services in Jakarta have been managed by two private concession companies which serve the western and eastern sides of the city under 25-year public private contracts. These contracts have been renegotiated several times. There are few formal mechanisms for coordination among these actors and the central government’s role is limited to largely advisory and financing functions. While this fragmented governance structure may slow the adoption of IUWM policies and regulations at the national level, the lack of coordination may strengthen incentives on the part of the concessionaires to develop IUWM projects using locally available water sources, such as stormwater or greywater, which do not require the cooperation of local governments outside Jakarta and other external parties.

4 Results

Table 2 presents selected descriptive statistics for the 260 “kelurahan” or villages of Jakarta.

Table 2

Selected descriptive statistics.

	Mean	Minimum	Maximum
Area (km2)	2.47	0.28	12.98
Population	39,696	3038	154,003
Piped water access (% population)	36	0	100
Septic tank coverage (% population)	91	50	100
Toilet access (% population)	98	78	100
Diarrhoea (Number of cases/year)	479	0	2792
Water security score	71	55	80

Figs 1 and 2 show the spatial distribution of access to piped water supply and access to wastewater infrastructure respectively. Fig 3 shows the spatial distribution of composite water security scores. Fig 4 shows a screenshot of the dashboard for one village, Tebet Timur as an example.

Fig 1

Access to piped water in Jakarta by kelurahan (village).

Fig 2

Access to septic tank in Jakarta kelurahan (village).

Fig 3

Aggregated water security score by kelurahan (village).

Fig 4

Water security dashboard presentation example: Kelurahan Tebet Timur.

For those indicators not available at village level, city-level data is shown in Table 3. Flood infrastructure investment, governance framework and policy framework were discussed qualitatively in Section 3.

Table 3

City-level indicators.

	INDICATOR	UNIT	VALUE
1101	Surface water availability (reservoir vol.)	m3	234,1601
1102	Precipitation (annual)	mm	1816
1103	Rainfall intensity/variability	mm	±43–300
2103	Affordability	% of average monthly income	41
2201	Drinking water quality	% meet standards	97.52
2400	Flood protection infrastructure	Qualitative
4001	Institutional/governance framework	Qualitative
4002	Planning	Qualitative

Sources

1BPPSPAM (Badan Peningkatan Penyelenggaraan Sistem Penyediaan Air Minum). 2018. Buku Kinerga PDAM 2018: Wilayah II. Jakarta: BPPSPAM. Available at: http://sim.ciptakarya.pu.go.id/bppspam/assets/assets/upload/Wilayah_II_FA.pdf

2BRPAMDKI (Badan Regulator Pelayanan Air Minum). 2017. “Kinerja Kuartal I /2017: Tekanan dan Kualitas Air Minum Jakarta”. Available at: http://www.brpamdki.org/peformance-2017/detail/190/ Note: Drinking water quality is measured at the outlet of the Water Treatment Plant, not at the tap.

Table 4 reports correlation coefficients between variables. These coefficients capture the mutually reinforcing nature of some of the interlinked elements within the water system.

Table 4

Inter-variable correlation.

Indicator 1	Indicator 2	Correlation coefficient
Piped water coverage	Groundwater status	-0.45
Groundwater consumption	Groundwater status	0.33
Septic tank access	Groundwater status	0.04
Slum density	Flood incidence	0.18
Economic activity (radiance)	Flood incidence	-0.31
Economic activity (radiance)	Elevation	-0.53

Groundwater status is measured as a 3-way classification: 1 = safe/recharge zone; 2 = prone, 3 = critical/damaged

5 Discussion

The data suggest that the “kelurahan” or village is a suitable unit size for implementation and monitoring of IUWM interventions in terms of population, with the majority having 10,000–100,000 residents. 15 of the 260 villages have a population below 10,000 and in these cases two or more neighbouring villages with similar characteristics could be clubbed or bundled together.

As expected, coverage of piped water supply is found to vary widely across the city. This is illustrated in Fig 1. It should be noted that the map shows the proportion of population with a connection by area. It therefore captures both the physical extent of the network and the density of connections to the network. A low density of connections may reflect either constraints on the part of the household or utility to secure a connection, or a lack of demand for connections from households in areas where there are alternative water sources.

A second key impact variable, access to toilets, also varies widely across the city. In ten villages, more than 10% of the population have no access to toilets. Nine of these ten villages are located in northern areas of the city. As we would expect, these areas also have below-average septic tank coverage and higher prevalence of diarrhea.

The extremely limited reach of the centralized sewerage network in Jakarta has been noted in previous studies [48], but the data, illustrated in Fig 2, show that household level infrastructure is also limited in some areas, with 35 villages in which more than 20% of the population does not have access to a septic tank. It can be seen that most of the villages with less than 80% access to a septic tank are located along the lower Ciliwung River, a heavily polluted river [49]. This is consistent with a 2018 study which found that 70–80% of water pollutants in the Ciliwung are from municipal sewage [47], raising risks to health and environmental quality.

These findings may underestimate the health risk posed by inadequate wastewater infrastructure because many septic tanks may be badly installed or poorly maintained and thus are not effective in treating household wastewater. The unsafe disposal of household wastewater is of particular concern in areas of the city where there is a high reliance on groundwater for household use but it is also a concern in areas served by piped supply where low pressure and deteriorated pipe quality may allow infiltration of contaminated groundwater into the tap water distribution network.

Fig 3 shows the spatial distribution of the composite water security score. As such, it brings together the information on hazard, pressure and impact into a single metric which can be used as an initial guide for the prioritization of IUWM projects. There are 36 villages in the lowest score category, corresponding to an overall low level of water security. They are clustered in central Jakarta on the banks of the Ciliwung River, along the northern coast and in the south-west of the city. The central areas are characterised by older, high density housing. Although the piped network extends into these areas, a large proportion of households do not have connections. The coastal villages face underlying pressure from their location at low elevations and exposure to multiple flood types (coastal, riverine and pluvial). Many of these villages also have a higher proportion of slum households. Villages in the south-west of the city are unserved by the piped network, which accounts for the low scores in those areas.

The data allow us to investigate further the relationships between individual indicators to understand the strength of the relationship between components of the urban water system. Fig 5 shows the relationship between piped water coverage and groundwater status. Just over half (53%) of the villages in our low score group are located in areas in which groundwater is classified as damaged or critical. The correlation is moderate (correlation coefficient: -0.45) with lower levels of piped water coverage associated with critical groundwater status (low availability and quality). Thus residents of these areas face a double challenge, as they do not have access either to piped water or to safe groundwater, implying an urgent need to develop new sources of safe water supply for residents in these areas. Fig 6 suggests that this situation is likely to deteriorate further in the future as daily groundwater consumption is higher in areas with poor groundwater status (correlation coefficient: 0.33). This may reflect the need for residents to rely on groundwater for water supply even though they may need to sink wells deeper to reach dwindling groundwater reserves.

Fig 5

Piped water coverage and groundwater status.

Fig 6

Groundwater consumption and groundwater status.

There is no significant correlation between prevalence of septic tanks and the measure of groundwater status used (Fig 7). As poor groundwater quality is perceived to be a concern in areas with low prevalence of septic tanks and where septic tanks may not be functioning effectively, the absence of correlation may be due to the particular indicator of groundwater status available, which does not include bacteriological contamination.

Fig 7

Septic tank access and groundwater status.

Figs 8–10 show the relationship between economic activity, poverty and flooding. Flood incidence is a backward-looking measure which captures how many times an area flooded over 2013–2016, the most recent period for which data are available. Fig 8 shows a positive, moderate-weak correlation (0.18) between the proportion of slum households in the area and flood incidence, reflecting the concentration of low-income households in areas with higher flood risks. This underscores the need to take socioeconomic dimensions of vulnerability into account in flood risk management interventions.

Fig 8

Slum density and flood incidence.

Fig 10

Radiance and elevation.

Fig 9 shows the relationship between economic activity, proxied by radiance, and flood incidence. It shows a moderate negative relationship between the two variables, which may reflect the fact that economic activity has been re-located outside the most flood prone areas or higher levels of flood protection infrastructure have been built in these areas. This may be considered an encouraging finding in terms of the property value at risk from flooding but it may also raise equity concerns if flood defence investment is concentrated in these areas at the expense of flood-prone residential districts. Moreover, Fig 10 shows potential high future economic exposure to flood damage. Using elevation as an indirect proxy of future flood exposure (in the absence of adequate flood protection infrastructure), the figure shows clustering of areas of high economic activity at elevations below sea-level and exposure is likely to increase in the future as a result of continuing land subsidence in the city.

Fig 9

Radiance and flood incidence.

In summary, the data allow us to identify areas with critical groundwater status, high groundwater consumption, low piped supply coverage and low septic tank use which would be suitable priority areas for IUWM interventions. The scores also illustrate the value of micro-level water security analysis as there is variation in each indicator score among villages, such that each village or a cluster of villages may warrant different IUWM interventions.

6 Conclusions

The analysis points to the urgent need to develop new sources of water to increase household access to safe water supplies, reduce dependence on low-quality groundwater and control the over-abstraction of groundwater in certain parts of the city. The potential for IUWM interventions to address these challenges was considered by stakeholders at focus group discussions.

Three types of IUWM projects were identified for their applicability in Jakarta: rooftop rainwater harvesting on large buildings; on-site greywater recycling in commercial and industrial facilities; and decentralized small-scale wastewater treatment systems. Rainwater harvesting and on-site recycling were considered to be feasible and beneficial given the existing policy regime, institutional framework and availability of resources, but stakeholders identified a range of regulatory, financial and organizational constraints to the development of these projects. Minimally, regulations should allow for connections to micro-networks to count towards the concessionaires’ targets for increasing connections, as long as the quality of the water provided meets drinking water standards.

As the concession contracts come to an end in 2023, there is an opportunity to shape the future governance framework to one which would actively support the adoption of IUWM through targets, incentive schemes, contracts and coordination mechanisms at the municipal level, at higher tiers of government and with financing institutions. Furthermore, Jakarta’s water system is heavily influenced by conditions and actions taken upstream and in neighbouring jurisdictions. Mechanisms of oversight and coordination between upstream and downstream local governments are currently weak and will need to be strengthened in order to achieve policy goals efficiently and effectively.

Drawing on and analyzing data from multiple sources, primarily public, suggests that there is value in inter-ministerial or inter-agency collaboration in data-sharing and policy intervention in multi-faceted issue areas like urban water systems. From a micro-level to a transboundary scale, the interaction between ecological, social and economic variables is important in identifying effective IUWM efforts.

In order to refine the analysis further, more precise data on ground and surface water quantity and quality, piped water service quality, subsidence and flood risk would be required. Some of this data has been collected but is held by government agencies, concessionaires and researchers and is not made public. Bringing this data into the public domain could improve policy design and implementation and should be supported by government.

In this paper, IUWM has been understood as an approach and the project types that we have highlighted and explored in initial engagements with stakeholders are suggestive rather than exclusive. The major tasks of setting the scope, technology and arrangements for design and delivery of individual IUWM projects remain to be undertaken. Ideally, the use of IUWM to meet policy objectives in Jakarta can be made more effective through a strong evidence base, while allowing scope for innovation and refinement to meet local needs.

DKI Jakarta urban water security indicators data details and sources.

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5 Nov 2019

PONE-D-19-19667

Urban water systems: development of micro-level indicators to support integrated policy

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Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

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The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript aspires to provide a set of criteria for prioritizing adoption of integrated urban water management practices in Jakarta, Indonesia. The particular contribution the authors seek to make is two-fold: to first provide a set of indicators of water insecurity/security; and second, to provide hard data, based on locally-available sources of information, to help calibrate the magnitude of these local water security indicators. The effort is worthy of being pursued and refined - and the results could be publishable with additional thought and more rigorous conceptualization of certain challenges - as noted below. However, at this stage the work insufficiently considers important foundational principles needed to generate outcomes useful to decision-makers - and to advancing scholarship on IUWM. There are four major problems with the argument.

First, the authors fail to demonstrate why the mere provision of good data and innformation on water security alone should induce institutional change or adoption of these indicators as reasons for implementing IUWM (e.g., lines 112-115). Given the risk aversion of many water agencies toward innovative measures generally, it may be the case that action to implement IUWM would not be induced through identifying the most urgent areas in a city with major water security problems, but instead, in identifying those areas where programmatic change might be easiest to bring about because change would be less prone to political or public resistance. Similarly, the authors have not effectively made the case that where changes at the city level are difficult to implement, that locality or district implementation of IUWM could be easier (lines 85-87). Why should this be so? What incentives or motivations facilitate confidence that these measures are easier to implement in smaller areas?

Second, given that water supply within Jakarta's otherwise fragmented mangement and governance system for water provision is currently privatized and controlled by two enterprises (lines 280-283), would it not be reasonable to expect some possible resistence to implementation of IUWM measures, particularly if their adoption might affect profit margins and/or managerial control of water sources? A number of studies of this challenge, including at least one on Indonesia, are worth incorporating in this context - see, for example, the following:

1. Birdsall, N. and Nellis, J. (2003) ‘Winners and Losers: Assessing the Distributional Impact of Privatization’, World Development 31 (10): 1617-33.

2. Davis, J. (2004) ‘Corruption in Public Service Delivery: Experience from South Asia’s Water and Sanitation Sector’, World Development 32 (1): 53-71.

3. Al 'Afghani, M. M. (2012), Anti‐Privatisation Debates, Opaque Rules and ‘Privatised’ Water Services Provision: Some Lessons from Indonesia. IDS Bulletin, 43: 21-26. doi:10.1111/j.1759-5436.2012.00303.x

Third, the authors do not enumerate precisely what they mean by IUWM measures and what specific suites of such measures would be appropriate for the tackling of Jakarta's water security challenges (lines 402-406, especially). Would these be measures to better conserve and/or increase the end-use efficiency of potable water use; reuse of wastewater/harvesting stormwater for public use? In the Jakarta context, what might be an IUWM practice, or suite of practices, that have been actively discussed by decision-makers (lines 448-450, for instance)?

Finally, the authors fail to account for recent research which tries to link indicators of water security - in the sense of urgent water problems whose solution is not tractable under current urban water management schemes - with incentives for institutional changes (this could expland tjheir discussion on lines 430- 431, for example). this is something that Peter Gleick, for example, refers to as "predictors of urban water transitions" (Peter H. Gleick, Transitions to freshwater sustainability, PNAS September 4, 2018 115 (36) 8863-8871; https://doi.org/10.1073/pnas.1808893115). Gleick's work could be useful in helping characterize the types of indicator data that would be most useful for inducing such transitions to be pursued by decision-makers.

Finally, there are a number of more minor, but important issues, omitted or skirted in the manuscript that need to be addressed. For example, line 32 should state "these systems" (plural); line 48 should re-state as "centrally-operated distribution and treatment systems." Finally, in the discussion of flood risk as a water security issue (lines 252 and 253) the authors fail to elaborate on why structural measures taken have been insufficient in reducing risk. Is it due to an increase in impervious surface; more land being prone to flooding due to land settling; a greater risk to populations who have chosen to reside in low-lying areas over time; or some combination of these factors? Similarly, on lines 396-7, the econimic exposure to flood damage in some districts may reflect a different phenomenon - that the poorest, most vulnerable, and least economically productive population lives in flood prone districts. This possibility should at least be explored.

Reviewer #2: This paper proposes a set of performance indicators to priorize integrated water projects. A system approached is used for this purpose. The city of Jakarta is used as a case study. Although the topic of the paper is valid to be investigated, the paper suffers from several issues that need improvements. Some of them are the following:

a) The paper needs of a strong revision, including the English language and the elimination of several typos;

b) The indicators proposed, a better justification and a more holistic approach should be adopted. For example, see the paper of Marques et al. (2015) in Environmental Science & Policy. Vol. 54, pp. 142-151.

c) The systems approach adopted needs to be justified. Why not MCDA?

d) The introduction should be improved including a clear description of the objectives, methodology and the contributions for the literature;

e) The conclusions should provide policy implications of the research carried out.

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Reviewer #1: Yes: David Lewis Feldman

Reviewer #2: No

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20 Dec 2019

Responses to Reviewers

PONE-D-19-19667
Urban water systems: development of micro-level indicators to support integrated policy

We are very grateful to the reviewers for their comments and have sought to revise and improve the paper accordingly. Changes are indicated in red in the revised manuscript.

Reviewer #1: The manuscript aspires to provide a set of criteria for prioritizing adoption of integrated urban water management practices in Jakarta, Indonesia. The particular contribution the authors seek to make is two-fold: to first provide a set of indicators of water insecurity/security; and second, to provide hard data, based on locally-available sources of information, to help calibrate the magnitude of these local water security indicators. The effort is worthy of being pursued and refined - and the results could be publishable with additional thought and more rigorous conceptualization of certain challenges - as noted below. However, at this stage the work insufficiently considers important foundational principles needed to generate outcomes useful to decision-makers - and to advancing scholarship on IUWM. There are four major problems with the argument.

First, the authors fail to demonstrate why the mere provision of good data and information on water security alone should induce institutional change or adoption of these indicators as reasons for implementing IUWM (e.g., lines 112-115). Given the risk aversion of many water agencies toward innovative measures generally, it may be the case that action to implement IUWM would not be induced through identifying the most urgent areas in a city with major water security problems, but instead, in identifying those areas where programmatic change might be easiest to bring about because change would be less prone to political or public resistance.

We agree absolutely that the provision of information by itself does not induce institutional change. Our motivation for focusing on the case of Jakarta for this study is that a confluence of factors has opened a policy space for IUWM there at the present time.

In particular, the central government has set ambitious targets to expand access to safe water supply and sanitation and has expressed its support for using IUWM approaches to reach the targets. Local governments are responsible for meeting the water supply targets but face severe raw water resource constraints as groundwater abstraction is increasingly strictly regulated and surface waters are declining in quality and fully allocated in the Jakarta metro area. Thus, in Jakarta, the local government, water utility and concessionaires are seeking to identify additional sources of water from within the jurisdiction.

The shift towards IUWM is backed by international financial institutions, notably the World Bank, which has launched an IUWM initiative, with a view to establishing a financing facility, and by non-governmental organisations such as APEKSI, the organisation of municipal governments.

We therefore see these indicators as playing a double role, first in helping policy-makers, planners and managers in Jakarta to direct investment to those areas with the greatest need in order to meet government targets effectively and efficiently and secondly to help central government agencies and lenders to monitor progress towards water and sanitation targets. While it is often the case that sustainability indicators are not used by decision-makers (Lehtonen, M. 2013 The non-use and influence of UK energy sector indicators. Ecol. Indic. 35, 24–34.), we hope to increase the likelihood that these indicators will be used by consulting with stakeholders during the development of the indicators and linking them to their policy objectives.

We have included some additional information on the interactions with stakeholders in the revised version of the paper (Sections 2 & 6).

Similarly, the authors have not effectively made the case that where changes at the city level are difficult to implement, that locality or district implementation of IUWM could be easier (lines 85-87). Why should this be so? What incentives or motivations facilitate confidence that these measures are easier to implement in smaller areas?

The paper did not distinguish clearly between the level at which design and planning of IUWM takes place and the scale of the interventions. In the case of Jakarta, the actors leading on selecting, designing and implementing IUWM projects would be Pam Jaya, the public water utility, and the two private concessionaires, reflecting the allocation of authority under the current governance structure. On the other hand, the IUWM interventions which are under consideration are small-scale interventions like rainwater harvesting, onsite water recycling and distributed micro wastewater collection and treatment systems. These small-scale projects are considered to be more promising for a number of reasons. Firstly, conditions vary widely across Jakarta in terms of the coverage of the water supply network, quality of service (pressure, continuity), groundwater level and quality, flood risk etc. so appropriate project types are likely to vary across localities. Secondly, the existing sewage and drainage systems are very limited, necessitating very high upfront investment to develop centralised reuse using wastewater or stormwater (as applied in Singapore, for example). Thirdly, as IUWM is not yet well established in Indonesia, pilots are needed to demonstrate benefits and costs in the context of a tropical mega-city. We have revised the paper to clarify the role of Pam Jaya and the concessionaires.

Second, given that water supply within Jakarta's otherwise fragmented management and governance system for water provision is currently privatized and controlled by two enterprises (lines 280-283), would it not be reasonable to expect some possible resistance to implementation of IUWM measures, particularly if their adoption might affect profit margins and/or managerial control of water sources?

It is correct that the concessionaires might resist IUWM if it led commercial and industrial customers to switch from piped water to onsite harvested or recycled water. However, the private companies have expressed their support for IUWM in principle. This is in part explained by the fact that many of industrial and commercial customers currently rely on groundwater rather than piped water so switching would reduce the pressure on groundwater resources rather than affecting piped water demand. Furthermore, under the contracts the concessionaires receive a fee for each cubic metre of water billed (regardless of the tariff paid by the customer under the tiered tariff structure) and are thus incentivised to increase coverage and to increase continuity of supply and pressure for existing customers. As they have not been able to negotiate an increased allocation from the city’s main external raw water source, expanding supply will only be possible if they can develop new water sources within their jurisdiction.

It is also relevant to note that the concession contracts will reach the end of their term in 2023 and government parties are currently considering options for the structure of service provision. The future operator is likely to be a public company and will face similar challenges to the concessionaires in expanding supply. IUWM initiatives taken now will allow the government to assess their suitability under new governance arrangements after 2023.

Third, the authors do not enumerate precisely what they mean by IUWM measures and what specific suites of such measures would be appropriate for the tackling of Jakarta's water security challenges (lines 402-406, especially). Would these be measures to better conserve and/or increase the end-use efficiency of potable water use; reuse of wastewater/harvesting stormwater for public use? In the Jakarta context, what might be an IUWM practice, or suite of practices, that have been actively discussed by decision-makers (lines 448-450, for instance)?

This was the subject of focus group discussions held with stakeholders in Jakarta in October 2019. The project types identified are summarised briefly in Section 6. Our expectation is that the suite of project types considered by stakeholders will evolve and expand over time.

Finally, the authors fail to account for recent research which tries to link indicators of water security - in the sense of urgent water problems whose solution is not tractable under current urban water management schemes - with incentives for institutional changes (this could expand their discussion on lines 430- 431, for example). this is something that Peter Gleick, for example, refers to as "predictors of urban water transitions" (Peter H. Gleick, Transitions to freshwater sustainability, PNAS September 4, 2018 115 (36) 8863-8871; https://doi.org/10.1073/pnas.1808893115). Gleick's work could be useful in helping characterize the types of indicator data that would be most useful for inducing such transitions to be pursued by decision-makers.

Thank you for pointing us towards Gleick’s work on water transitions which is indeed relevant. The current situation in Jakarta combines several of the conditions identified by Gleick - resource constraints coupled with failures of the existing system leading to over-abstraction of groundwater, subsidence and inadequate provision of safe water supply and sanitation. We have incorporated these points in lines 111-120.

Finally, there are a number of more minor, but important issues, omitted or skirted in the manuscript that need to be addressed. For example, line 32 should state "these systems" (plural); line 48 should re-state as "centrally-operated distribution and treatment systems."

Corrections made.

Finally, in the discussion of flood risk as a water security issue (lines 252 and 253) the authors fail to elaborate on why structural measures taken have been insufficient in reducing risk. Is it due to an increase in impervious surface; more land being prone to flooding due to land settling; a greater risk to populations who have chosen to reside in low-lying areas over time; or some combination of these factors?

We have rewritten this section which was misleading. Structural measures – dredging, enlargement of flood water storage capacity – have been effective in reducing flood risk. However, several other factors are increasing flood risk at the same time: changes in upstream land use leading to higher water volumes and velocity, and land subsidence downstream. The measures taken are expected to be inadequate to withstand future pressures.

Similarly, on lines 396-7, the economic exposure to flood damage in some districts may reflect a different phenomenon - that the poorest, most vulnerable, and least economically productive population lives in flood prone districts. This possibility should at least be explored.

We agree with this point, which is reflected in Figure 8, lines 423-4 and 431-2.

Reviewer #2: This paper proposes a set of performance indicators to prioritize integrated water projects. A system approached is used for this purpose. The city of Jakarta is used as a case study. Although the topic of the paper is valid to be investigated, the paper suffers from several issues that need improvements. Some of them are the following:
a) The paper needs of a strong revision, including the English language and the elimination of several typos;

We have reviewed the text thoroughly and have made corrections.

b) The indicators proposed, a better justification and a more holistic approach should be adopted. For example, see the paper of Marques et al. (2015) in Environmental Science & Policy. Vol. 54, pp. 142-151.

This point is well taken, and we have extended and deepened Section 2 of the paper in order to address this. The initial selection of indicators is drawn from van Ginkel et al 2018. In our view, this set of indicators is holistic as it covers the different facets of water – social, economic and environmental; its different uses; and associated risks. From this larger set, we focus on a subset of indicators which vary at the micro level for the analysis. We are unable to populate all the indicators due to data constraints and use proxies where possible.

c) The systems approach adopted needs to be justified. Why not MCDA?

This is an important point and we have sought to express this more clearly in lines 144-150. The systems approach is well suited to capture the interrelated mechanisms of the urban water system and can shed light on relationships of cause and effect between indicators, and thus to inform the selection of interventions. At this stage, we have not sought to prioritize and weight the indicators, focusing instead on the relationships between them. Future work could employ MCDA to address this.

d) The introduction should be improved including a clear description of the objectives, methodology and the contributions for the literature;

We have clarified the objectives and contribution in lines 103-109. The selection of the study site is explained in lines 111-120. The approach and method are detailed in Section 2.

e) The conclusions should provide policy implications of the research carried out.

We have revised the concluding section (Section 6) to draw out policy implications and directions for further research. Following the initial submission of this paper, a stakeholder workshop was held in Jakarta to discuss suitable IUWM models and to discuss the opportunities and constraints for IUWM and the findings are reported briefly in the revised version. Future work will focus on identifying barriers to the development of these IUWM project types in the priority locations identified.

Submitted filename: Urban water system responses to reviewers.docx

Click here for additional data file.

13 Jan 2020

Urban water systems: development of micro-level indicators to support integrated policy

PONE-D-19-19667R1

Dear Dr. Jensen,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Monjur Mourshed, Ph.D., B.Arch.

Academic Editor

PLOS ONE

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Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have effectively responded to all my comments on the initial draft submission and the manuscript is much improved.

Reviewer #2: The paper is much better now and I recommend its acceptance. Congratulations and good lucky to the authors.

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: David L Feldman

Reviewer #2: No

7 Feb 2020

PONE-D-19-19667R1

Urban water systems: development of micro-level indicators to support integrated policy

Dear Dr. Jensen:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

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