Legal Analysis of Reclaimed Wastewater Management in Indonesia: Reference to Malaysia and Singapore

Abstract

Indonesia faces a significant challenge in wastewater management, exacerbated by environmental degradation and the changing climate. This study addresses two main questions: What is the legal framework governing reclaimed wastewater management in Indonesia? How is the implementation of reclaimed wastewater management conducted in Indonesia? The answers to these questions guide the objectives of analyzing national and international regulations to identify barriers and proposing improvements through a normative legal analysis method with primary legal material, focusing on international, national, and local regulations regarding wastewater reclamation. The findings reveal that although Indonesia has established a legal framework for wastewater management, it lacks a clear enforcement mechanism, and its implementation is fragmented at the local level. Due to regional disparities, such policy implementation should evaluate and adopt suitable international best practices on wastewater treatment and recycling mechanisms. This study recommends policy harmonization, increased investment in infrastructure, and the adoption of best practices in sustainable wastewater management. Public awareness and private sector engagement are also essential to ensuring effective implementation and long-term sustainability.

1. Introduction

In 2022, the Intergovernmental Panel on Climate Change (IPCC) reported that approximately 50% of the world’s population suffered from water scarcity, a situation projected to worsen due to climate change and increased population [1]. Indonesia is similarly affected by rapid demographic growth, which drives the increased demand for food production and industry expansion [2].

Wastewater reclamation refers to “the process of converting sewage or industrial wastewater into water that can be reused for a variety of applications” [3]; these applications include road cleaning, irrigation, agriculture, landscape fountains, and even industrial facilities [4]. This study focuses on the reclamation of wastewater at the domestic or household level. Domestic wastewater is defined as “water that has been used by a community and which contains all the materials added to the water during its use” [5]. Waste originates from bathrooms, latrines, kitchens, washing clothes, and washing household appliances [6].

Although domestic wastewater may appear less harmful than industrial wastewater, urbanization has led to increased waste generation from households, often with higher pollutant concentrations than industrial sources [7]. Approximately 60–75% of domestic wastewater is from households. Thus, it is critical to treat wastewater due to its harm to the environment and health. Duncan Mara highlights that in developing countries, the treatment of domestic wastewater remains rare due to financial constraints, a lack of awareness and knowledge, and the economic value of wastewater treatment [8].

This study is structured into three parts. The first part of this study evaluates the development of the existing international, national, and domestic levels regulating water, particularly wastewater reclamation management. In the second part, it investigates the factors hampering wastewater reclamation in Indonesia and scrutinizes the legal strategies used to overcome wastewater management issues in the neighboring states of Malaysia and Singapore. Suggestions are provided in the last part of this research.

2. Materials and Methods

This research adopts a qualitative legal approach, incorporating doctrinal and comparative analysis. It examines primary legal sources, including international agreements, national statutes, and regional regulations related to wastewater reclamation in Indonesia. Secondary materials such as scholarly publications, policy documents, and case studies are reviewed to evaluate the effectiveness of existing legal frameworks. A regional analysis dividing Indonesia into western, central, and eastern regions (

Table 1. Geographical sample for legal analysis.

No	Areas Covered
	Indonesia	Region
1	Jakarta Special Area (DKI Jakarta)	Western Indonesia
2	Manokwari, West Papua	Eastern Indonesia
3	Jayapura, Papua	Eastern Indonesia
4	Makassar, South Sulawesi	Central Indonesia
5	Samarinda, East Kalimantan	Central Indonesia
6	Yogyakarta Special Region	Western Indonesia

) further highlights local governance challenges and regulatory inconsistencies.

3. Results

3.1. International Efforts Towards Clean Water and Sanitation

Global initiatives addressing wastewater management are essential for achieving effective water management and environmental sustainability [9,10]. Urbanization has been closely linked to increased water consumption and sewage production, which poses significant hurdles as water resources become increasingly scarce [11]. Wastewater management has been a long-standing challenge with increasing quantities of sludge generated by wastewater treatment plants [12] contributing to serious environmental pollution [13]. With approximately 48% of global wastewater production being released untreated into the environment [14], the wastewater discharge of harmful substances and materials into rivers and aquifers needs to be properly regulated to ensure water quality in both surface and subsurface water systems [15].

To gain a comprehensive understanding of the development of international law in terms of regulating domestic wastewater management, the following discussion will focus on three interrelated international legal frameworks: international water law, international environmental law, and international human rights law (Figure 1).

3.2. Development of Wastewater Reclamation Regulations

The international community initiatives related to water management have played a significant role in influencing policy, implementation, and research efforts to extend and improve water and sanitation services on a global scale [16], the most recent being the United Nations’ Sustainable Development Goals (SDGs) as part of the 2030 Agenda for Sustainable Development. Specifically, Goal 6 focuses on ensuring access to water and sanitation for all and their sustainable management [17,18].

Efforts to advance global water governance have been facilitated by the establishment of the International Water Supply Association (IWSA) [19] and the International Association for Water Pollution Research, which sought to provide assessments of water quality for specific uses. The merger of the IWSA and the IWQA as the International Water Association (IWA) marked a significant step in promoting high standards and innovative practice in the field of sustainable water management, including sewerage services (Figure 2).

In 1990, a joint initiative between the World Health Organization (WHO) and the United Nations Children’s Emergency Fund (UNICEF) led to the establishment of the Joint Monitoring Program (JMP) to oversee the accessibility of safe drinking water, including the percentage of the population utilizing an “improved” drinking water source [20]. The Water Supply and Sanitation Collaborative Council was established through a resolution passed by the United Nations General Assembly at the conclusion of the International Drinking Water Supply and Sanitation Decade, with the aim of promoting the sustainable development of water, sanitation, and hygiene [21].

The United Nations Conference on the Human Environment held in Stockholm in June 1972 emphasized the importance of international support for developing countries, particularly on vital infrastructure for water supply and sewage water treatment [22]. It also addressed the roles of UN agencies, including the Food and Agriculture Organization (FAO) and WHO, in water quality governance. It called for international collaboration in researching, controlling, and regulating national activities that impact the aquatic resources of other nations [22,23].

Development in the water supply and sewerage services sector also corresponds to the Dublin Statement made at the 1992 the International Conference on Water and the Environment. It proposed four guiding principles which are as follows: (1) freshwater is a finite and vulnerable resource; (2) water resources should be managed participatorily; (3) women’s roles in providing, managing, and protecting water are important; and (4) water should be recognized as an economic resource [24]. The same year, the United Nations Conference on Environment and Development (UNCED) adopted a set of principles for sustainable development and Agenda 21, in which Chapter 18 emphasized the importance of Integrated Water Resource Management (IWRM) [25]. This will ensure sustainable water resource approaches that reflect the economic value of water, as proposed by the Dublin Statement [26,27], including the utilization of marginal-quality water sources, wastewater reuse and recycling, energy generation from waste, and the integration of wastewater reuse into agricultural practices. These approaches promote efficient and responsible water usage while mitigating environmental impacts. Chapter 21 of Agenda 21 also highlights the advancement of environmentally sound management practices of solid waste and sewage-related concerns [28].

The 1972 Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (the London Convention) was adopted with the objective of regulating wastewater and protecting the marine environment to address the issue of the dumping of wastes at sea. The Havana Summit mandated states to introduce technologies for affordable sanitation and industrial and domestic wastewater treatment by mitigating the effects of groundwater contamination and establishing national-level monitoring systems and effective legal frameworks [29].

In 2002, an international agreement was reached by the UN Committee on Economic, Social and Cultural Rights, which recognized the significance of water as a crucial and limited resource with multifaceted roles in terms of economic, social, and environmental functions. It acknowledged the right to access clean and affordable water and the need to improve water resource management. It recommended that there should be the encouragement and promotion of knowledge-sharing and the provision of capacity-building and technology transfer. These should be undertaken in accordance with mutually agreed terms, including the use of remote sensing and satellite technologies, with a particular focus on developing countries and countries with economies in transition [29].

3.3. International Legal Principles of Clean Water and Sanitation

Over the past few decades, international environmental law has evolved to incorporate a number of cardinal principles that regulate the conduct of states in relation to the protection of the environment. These include the sic utere principle, the polluter pays principle, the principle of Environmental Sound Management, and environmental impact assessments. Later, the Rylands v. Fletcher ruling was also built upon these principles. Likewise, international law has used the principle of sic utere in the context of pollution, as frequently cited in the Trail Smelter arbitration decision [30,31].

Historical precedents [32,33] indicate that the application of the sic utere principle is based on two primary ideas (i) that the state possesses sovereignty over the management of its natural resources and (ii) that it remains subject to certain restrictions in order to prevent harm to other states. The principle requires the implementation of measures at an early stage, ideally before any damage occurs, so this necessitates the prohibition of activities that result in environmental harm.

One of the obligations that arises from the concept of sic utere is the prior assessment of potentially harmful activities. It can be argued that the Environmental Impact Assessment (EIA) represents the benchmark for determining whether due diligence has been properly exercised. Mechanisms that include monitoring, notifying relevant parties of potential problems, and exchanging information are incorporated as obligations into the majority of international environmental treaties, and these practices are also commonplace in the context of international water law [34,35].

The principle of sic utere was later reinforced through Principle 15 of the Rio Declaration [36]. This is evidenced by the inclusion of the phrase “it shall not be acceptable to postpone the implementation of cost-effective measures to prevent environmental degradation on the basis of a lack of complete scientific certainty”. Given the potential hazards posed by domestic wastewater, which might include hazardous chemicals or pathogens, Principle 15 aims to protect watercourses from pollution, particularly groundwater resources, and from damage that is irrecoverable from due to domestic wastewater pollution [37].

The sic utere principle also gave rise to the development of the polluter pays principle (PPP), a principle that has been widely accepted by various countries and is also a customary rule of law in the field of international environmental law. The necessity for liability rules is intended to facilitate the restoration of damaged environments and to cover the costs associated with the decontamination and remediation of contaminated sites [38]. On the same note, Principle 15 calls for states’ action at an early stage of any activity and, ideally, even before damage has occurred, despite the lack of complete scientific certainty concerning potential harm to the environment in a given situation [39].

The governance of domestic wastewater treatment is guided by fundamental principles, including EIA and Environmental Sound Management (ESM). These principles are founded in the international legal framework, which has the overarching objective of preventing, mitigating, and controlling transboundary environmental damage [40]. The obligation to conduct an EIA falls within Principle 17 of the Rio Declaration [41]. Most countries impose EIA for wastewater treatment [42,43], as it represents a legally sanctioned instrument designed to facilitate the identification, prediction, evaluation, and mitigation of the environmental consequences of planned projects.

EIA is also widely accepted as a mechanism through which the general public can participate in the planning and decision-making processes [44]. Furthermore, it serves the purpose of providing information and data to the public about projects and other activities. Conversely, ESM is exemplified by initiatives aimed at the preservation of water bodies from industrial discharges, the necessity of quantifiable and standardized limitations on effluent discharge, and the participation of treatment facilities in the administration of wastewater, prior to its reuse or release into the environment [45]

The necessity of transparent limitations and appropriate procedures for the disposal of wastewater, as well as the involvement of municipal wastewater treatment plants (WWTPs) in wastewater treatment management, is also an obligation of ESM in regulating domestic wastewater discharge. The distinction between EIA and ESM is characterized by the specific focus of each. The primary focus of EIA is the assessment and mitigation of environmental impacts associated with proposed projects [46,47]. In contrast, ESM is primarily concerned with the management and regulation of wastewater treatment and disposal, with the objective of preventing environmental damage [48,49]. Thus, it can be argued that the objective of EIA is to assess the potential environmental impact of a project or activity in advance, while ESM is a continuous process that begins at the inception of a project and continues until its completion.

3.4. Human Rights Perspective on Clean Water and Sanitation

The Universal Declaration of Human Rights 1948 held in Paris was the earliest attempt to incorporate the right to water into human rights. Water is a necessity for humans and all living creatures on earth. This was the main topic of discussion during the United Nations Conference on the Human Environment in 1972 and the Ministerial Conference on Drinking Water Supply and Environmental Sanitation in 1994. During the 1977 United Nations Water Conference in Mar del Plata, two critical resolutions were made to improve water development for agriculture and provide safe drinking water and sanitation in the community water supply.

The treatment of domestic wastewater is closely associated with several fundamental state obligations in terms of human rights. Firstly, it can be argued that the right to water is of paramount importance, given the fact that approximately 48% of domestic wastewater is frequently discharged into the environment without undergoing any form of treatment [50,51]. Such a practice has been identified as leading to a number of severe health and environmental harms [51,52]. In order for the human right to water and sanitation to be fully realized, it is necessary to ensure that water is safe to drink and that sanitation facilities are available. Articles 11 and 12 of the International Covenant on Economic, Social and Cultural Rights (ICESCR) set an obligation for state parties to take necessary measures for the safeguarding of water sources from contamination by harmful chemical substances and pathogenic microorganisms. This was to ensure that water intended for direct personal and domestic consumption remains uncontaminated.

The right to an environment that is free from harmful contaminants and pollutants is a fundamental aspect of human rights, with relevance to the treatment of domestic wastewater. The discharge of untreated wastewater has the potential to result in pollution, the emission of unpleasant odors, and the destruction of biodiversity [52]. It can be argued that states are obligated to assess the environmental impact of their own activities, to make relevant information public, to facilitate public participation in decision-making processes, and to make available appropriate remedies for harm caused by detrimental environmental actions. Such measures are important for ensuring transparency, accountability, and the protection of environmental rights.

Furthermore, the rights of indigenous populations are inextricably linked with the management of domestic wastewater, as these communities constitute an essential element within the state’s obligations to uphold human rights [53]. Indigenous communities are often the most adversely affected by the environmental degradation resulting from inadequate wastewater management practices [54]. These practices often fail to take into account the unique circumstances and cultural sensitivities of indigenous peoples. In order to ensure the sustainability and wellbeing of indigenous populations, it is essential to adopt an inclusive and culturally sensitive approach before conducting any activities within the territory of indigenous people [55,56,57].

On 28 July 2010, the General Assembly Resolution 64/292 adopted the “Human Right to Water and Sanitation”. This right recognizes the right to safe and clean drinking water and sanitation as a human right essential for the full enjoyment of life and all human rights. It also calls upon states and international organizations to “provide financial resources, capacity-building, and technology transfer, through international assistance and cooperation, in particular to developing countries, to scale up efforts to provide safe, clean, accessible, and affordable drinking water and sanitation for all”. The passing of this resolution is seen as highly opportune as it support the international commitment to clean water and sanitation under the Sustainable Development Goals, (Figure 3) particularly on Goal 6 [58].

3.5. Development of Laws on Clean Water and Sanitation in Indonesia

Numerous legislations in Indonesia address issues related to wastewater [58]. However, the predominant focus of municipal wastewater treatment has been on discharge into water bodies, with limited consideration for reuse and recycling. The adequacy and successful implementation of these laws in managing reclaimed wastewater need improvement. Consequently, both countries face challenges in harmonizing laws related to reclaimed wastewater, potentially affecting resource recovery for high-quality water and overall water sustainability.

One example may be observed in Jakarta. Based on the current identified issues, the Indonesian Government through Ministerial Regulation (Permen) of Public Works and Public Housing (PUPR) No.04/2017 concerning Domestic Wastewater Management was translated into the Governor Regulation of DKI Jakarta No. 122/2005 concerning Domestic Wastewater Management, which was then followed by the legislation of Governor Regulation No. 2/2013 concerning Domestic Wastewater Management and Governor Regulation No. 31/2022 concerning Detailed Spatial Planning of DKI Jakarta [59]. To implement the given mandate, the Provincial Government of DKI Jakarta, through the Jakarta Provincial Water Resources Agency, is preparing an Urban and Settlement Scale Domestic Wastewater Management System (Sistem Pengolahan Air Limbah Domestik (SPALD)), consisting of the construction of wastewater treatment plants (Instalasi Pengolahan Air Limbah (IPAL)) and piping networks [60]. The development of urban and settlement-scale SPALD is considered a solution to address water pollution issues amid population growth. The presence of IPAL can be utilized to improve access to wastewater services, enhance environmental quality in surface water and groundwater, and serve as an alternative source of raw water for clean water in the community. The system includes the construction of IPAL and piping networks that have been installed in nine locations which will flow through the Setia Budi dam and be reclaimed through an aerator which eliminates the pathogens carried by the pumped water from the river. This is in accordance with Permen PUPR 4/2017, serving as a guideline for SPALD implementers to provide domestic wastewater management services to the entire community.

These initiatives can only reclaim 4% from accumulated wastewater each day, sourced from 8 out of 13 rivers polluted by households and industry [61]. Although 75% of wastewater generation is contributed by domestic sources (1,038,205 m³/day), it is imperative to address wastewater sourced from industry in maintaining the Biochemical Oxygen Demand level well below the regulated threshold (150 mg/L) [62]. This issue may be addressed through a larger-scale integrated sewerage system that is able to reclaim wastewater from various sources.

The apparent lack of adherence to local regulations by both industrial entities and domestic actors underscores a troubling deficiency in our regulatory landscape. This laxity suggests that current local regulations may be insufficiently robust to effectively govern and oversee the activities of the domestic sector. When these guidelines are disregarded or circumvented, it not only compromises the integrity of the regulatory framework but also jeopardizes public welfare, environmental health, and equitable business practices. Consequently, there is an urgent need for policymakers and regulatory authorities to critically evaluate and potentially enhance these regulations. Strengthening regulatory mechanisms and promoting a culture of strict compliance are crucial endeavors to foster a more accountable, transparent, and socially responsible industrial ecosystem that safeguards both community interests and environmental sustainability.

Wastewater policy and addressing its challenges shall be performed in a multisectoral manner. Each ministerial/institutional line relevant to this issue must consult, plan, and decide which collective action must be taken while bearing in mind that Western Indonesia is not only composed of the capital city—Jakarta. Although Jakarta’s wastewater issue might be progressing, the unequal distribution of infrastructure and facilities among provinces/regions remains an issue leading to disparities in addressing challenges and advancing reclaimed wastewater. Therefore, an ideal step is to align prior local assessments on the reclaimed wastewater status quo from upstream to downstream and plan a suitable pathway for ensuring achievable, measurable policy interventions.

In 2010, the water availability for Papua indicated a surplus condition of river water [63]. However, in 2021, a report by the Ministry of Environment and Forestry highlighted that climate change and land use conversion resulted in changes to water quality [64]. Furthermore, poor waste treatment systems and intensifying industrial activity also contributed to this, bearing in mind that Papua, as a mining and industrial area, increasingly contributes to climate change. As a result, water quality in Papua is increasingly declining.

In 2020, liquid waste in Manokwari, West Papua, flowed across waterways. Liquid waste comes from the palm oil plantation business activities of PT. Medco Papua Green Aligned. However, according to the laboratory test results from a review by the Manokwari Regency Environmental Service, no intentional element was found in the flow of liquid waste. Responding to this incident, PT. Medco Papua Hijau Selaras conducted a study regarding land application and has received administrative sanctions by the Manokwari Regency Environmental Service [65]. Administrative sanctions are an implementation of Law Number 32 of 2009 concerning Environmental Protection and Management, where business actors are given sanctions as a form of taking responsibility for the water pollution that occurs.

In another case, Youtefa Bay, Jayapura, is a mangrove water area which was initially used by residents. However, various water content studies say that these waters have been contaminated by pollutants ranging from household waste to metal content. In contrast to the case in Manokwari, the water pollution that occurs in Youtefa Bay mostly comes from household waste. To solve this problem, the government needs to be aware that liability can not only be directed at individuals or business entities, but the government is also responsible. The water waste problem faced by the Papuan government has its own burden because the water waste content has been contaminated with metals or other chemical elements. So, in resolving issues like this, a special approach is needed, especially in processing and utilizing wastewater contaminated with chemicals so that it is useful and, most importantly, does not harm live elements. On the other hand, there are no Papuan government regulations or programs that regulate efforts to prevent and solve the wastewater issue.

In Eastern Indonesia, there is no specific regulation concerning wastewater policy. All the solutions to the current situation of contaminated water refer to Law Number 32 of 2009 concerning the Protection and Management of the Environment and are in accordance with Governmental Regulation Number 82 of 2001. These regulations only impose administrative sanctions on the business actor. However, there is an absence of preventive measures that are regulated under the current applicable law, especially considering that the dominant source of wastewater in Eastern Indonesia is domestic waste (public use). Therefore, the current applicable law is ineffective as the concatenation of wastewater has occurred continuously.

The growth rate of domestic wastewater in Makassar for several decades has not had a specific solution, even after the enactment of special regulations governing domestic wastewater in Makassar. However, recently, the Makassar government has just provided an update on conditions regarding centralized domestic wastewater management as part of the Metropolitan Sanitation Management Investment Project Program which aims to improve integrated wastewater services in urban areas [66]. This form of wastewater management will be ready to operate to support Makassar city sanitation services so that it will become a means to fulfill the domestic wastewater supply in the future. This project is supported by Load Asian Development funds which aim to help improve wastewater management in several cities in Indonesia (one of which is Makassar). In 2020, work on this project began, and in February 2024, this project was completed and then put into operation.

In contrast to Eastern and Western Indonesia, regional regulations in several regions in Central Indonesia tend to be more advanced. In Makassar, Regional Regulation Number 1 of 2016 concerning domestic wastewater management is the basis for implementing regulations for the wastewater management system. Meanwhile, in Samarinda, wastewater management has been regulated under Local Regulation No. 13/2006 concerning wastewater management in the city of Samarinda, where the government regulates wastewater discharge permits. Under this law, business actors are prohibited from disposing wastewater if the treated waste exceeds the quality value and causes water pollution [67]. Meanwhile, the government has an obligation to provide infrastructure as a special channel for the general disposal of household wastewater [67]. The division of responsibility between business actors and the government has a positive impact on liquid waste management in Samarinda. Furthermore, in 2021, the Samarinda City Environmental Service implemented an integrated pollution control information system (SIDAMAR) which can handle the technical approval application process for fulfilling wastewater quality standards, as well as reporting water and air quality data [68]. This assists the government in water and air quality reporting.

4. Discussion

4.1. Wastewater Reclamation Management in Indonesia

Indonesia’s domestic wastewater management is typically divided into two systems: individual (household-level septic tanks) and communal or centralized management. The use of septic tanks, despite being widespread, presents numerous challenges. Many households are still unaware that septic tanks require maintenance every three years. And there is no legal obligation that currently mandates such upkeep. This results in inefficient and often unsafe wastewater disposal, particularly in densely populated areas. Moreover, data show a correlation between low treatment levels and low income in the region [69]. By contrast, countries such as Finland and Singapore have adopted centralized wastewater management systems in approximately 80% of their urban areas, demonstrating far more effective outcomes than septic tanks [70,71]. Centralized systems offer Indonesia a viable path forward, although they involve significant financial demands for plant maintenance and infrastructure development. Additional funding from government budgets and modest user fees may be necessary to ensure long-term sustainability [72].

Despite resource constraints for the development of centralized wastewater management in Indonesia, it is not an unsolvable obstacle, as evidenced by the fact that Indonesia has initiated domestic wastewater management through IPAL. These facilities are designed to remove biological contaminants, allowing water to be reused for other purposes; however, the construction of IPAL in Indonesia has not been effective. If we look at data from wastewater management agencies, the number of IPAL that were successfully built in Indonesia until 2022 is only around 148 units; even several areas in Papua do not yet have their own centralized wastewater management agency [66]. Therefore, it can be seen that the construction of IPAL is still focused on densely populated areas and large urban areas in Indonesia. Apart from this, domestic wastewater management is a “basic service–mandatory–concurrent affair” and results from the joint competence of the central and regional governments [70]. This section aims to discusses several IPAL in regions in Indonesia and several states in pioneering sustainable wastewater management solutions [71].

In the Yogyakarta region, the Sewon and Semanggi IPAL systems exemplify effective implementation. These facilities reflect a balanced approach that addresses physical infrastructure, economic sustainability, and community engagement. The government regulates service charges through Gubernational Decree No. 62 of 2017, Concerning Evaluation Results of the Draft Yogyakarta City Regional Regulation Concerning Waste Water Levy, with fees ranging from IDR 0 to IDR 30.000 [73,74]. The costs are partially subsidized by public funds, private contributions, and the state’s budget. Although the IPAL systems were established by the government, local residents exhibit a strong sense of ownership and responsibility, seen by their desire to contribute [75]. Annual coordination between residents and stakeholders, including the appointment of community coordinators for each residential cluster, ensures the system’s smooth operation [76].

While regions like Sewon and Semanggi are among those that may effectively implement Ministerial Regulation PUPR No. 04/2017, IPAL deployment across Indonesia has not been applied consistently. For instance, in Papua, IPAL systems are mostly concentrated in urban centers such as Timika and Jayapura. Efforts to extend these services to more remote areas are hindered by logistical and financial challenges, particularly in locations with dispersed housing and poor access.

Ministerial Regulation PUPR No.04/2017 also sets specific geographic criteria for IPAL placement, including requirements for road access, elevation above flood-prone areas, and the avoidance of landslide-prone zones [76]. These conditions, while important for safety, further constrain development. For example, in the case of IPAL units in Semarang, the position of the IPAL lid in the area is considered to be in line with the ground so that water above the lid easily seeps and causes the container to fill up quickly [75]. A low score for the geographical suitability criterion was also observed in Sidoarjo, a densely populated area characterized by a high concentration of boarding houses. These conditions hinder the construction of integrated IPAL systems due to limited road access and community resistance, as these facilities are often perceived as disruptive. Additionally, a certain part of Sidoarjo lacks adequate infrastructure to support material transport and desludging operations, with roads that are very narrow, steep, and inaccessible to service vehicles. These geographical and logistical barriers prevent the complete installation of piping networks, particularly where the elevation of household toilets is incompatible with the IPAL network. Consequently, despite the existence of a legal framework for wastewater treatment in Indonesia, the effective implementation of IPAL systems remains a significant challenge [77].

4.2. Singapore Legal Framework on Wastewater Recycling

Singapore has achieved significant progress in wastewater recycling, transforming a once-vulnerable water supply system into one of the most advanced globally. Despite receiving adequate annual rainfall, Singapore’s small land area and limited water catchment capacity historically hindered its water self-sufficiency [54]. Faced with this challenge, Singapore prioritized water recycling not only for non-potable uses, such as toilet flushing and irrigation, but also potable purposes [77,78].

Singapore has extensive regulations related to water, as it was historically a key concern even in the 1970s. The limited land area for water storage and the absence of a water aquifer are major challenges to providing clean water for residents despite Singapore’s sufficient rainfall [78]. In order to fulfilled residents’ water needs with less reliance on imported water from Malaysia, the government then issued the Sewerage and Drainage Act in 1999, with its latest revision being in 2020, which regulates wastewater and drainage systems, including the responsibilities and standards for the construction, maintenance, and operation of sewerage systems [77,78]. The Public Utilities Board (PUB) is a statutory board under the Ministry of Sustainability and the Environment [79]. The PUB’s authority in terms of overseeing and water management stemmed from Public Utilities Act 2001. Section 3 legally constitutes the PUB as a statutory board, granting it the authority to perform its functions and responsibilities related to Singapore’s water management. In 2002, the PUB launched the NEWater program, which used cutting-edge membrane technologies to create a three-step treatment process (microfiltration, reverse osmosis, and disinfection). It is well within the World Health Organization’s Drinking Water Quality criteria and has passed over 150,000 scientific tests. NEWater is a weather-resilient source that contributes significantly to water supply’s resilience [78].

Singapore’s wastewater treatment process includes four progressive stages: preliminary treatment, primary treatment, secondary treatment, and tertiary treatment. It incorporates innovative technologies, such as the Deep Tunnel Sewerage System (DTSS), Membrane Bioreactors (MBRs), and reverse osmosis (RO) systems [80]. The DTSS is a large-scale infrastructure project designed to collect, treat, and dispose of wastewater through deep tunnels leading to centralized treatment plants, reducing the need for extensive land use. This system significantly reduces land usage and streamlines wastewater collection. MBRs and RO systems are employed in secondary and tertiary treatment processes to achieve higher levels of water purity. As of 2017, there are four major water reclamation plants that serve Singapore’s population of over five million. Changi treats 59%, followed by Ulu Pandan at 20%, Jurong at 11%, and Kranji at 10%. The treated water is used for both indirect potable reuse—where NEWater is mixed with reservoir rainwater to restore mineral content—and non-potable uses such as industrial processes and cooling systems [81].

In contrast, while Indonesia has begun to establish wastewater treatment plant efforts to manage its wastewater, it still faces significant challenges in this area. While there are some wastewater treatment plants and facilities, the majority of the country’s wastewater is not properly treated, leading to environmental and health concerns [80]. The lack of national policy and standard setting, the low public awareness of the importance of septage management, the lack of technical assistance and management support, and limited wastewater infrastructure could be the main challenges in applying wastewater treatment systems.

4.3. Malaysia’s Legal Framework on Sustainable Clean Water and Sanitation

Compared to the unitary government in Singapore, there are three levels of government in Malaysia: the federal, state, and local government. Each level of government has different levels of authority in the water sector, which may sometimes lead to fragmented water management strategies in climate change mitigation and wastewater management [82,83]. Under the Federal Constitution of Malaysia, the federal government typically oversees water infrastructure projects, the state government handles water resources within their territories, and the local government takes care of the drainage system in their localities [80,83]. Since water resources are within the purview of the state government, each state passed different laws pertaining to their rivers, and this has raised conflicts regarding shared river basins [84,85].

In Malaysia, Indah Water Konsortium (IWK) is a government-owned company responsible for managing and operating the country’s sewerage services. It handles the collection, treatment, and disposal of wastewater from residential, commercial, and industrial properties. IWK operates a wide network of sewage treatment plants, which treat wastewater before it is released into the environment. IWK is also responsible for maintaining the infrastructure associated with sewerage systems, including sewer pipes, pumping stations, and treatment plants.

To ensure the effective management of sewerage services, the Federal Constitution of Malaysia was amended in 2005 to remove jurisdiction on “water supply and services” from the state list to the concurrent list. This allowed the federal government to pass two important statutes, the Water Services Industry act (WSIA) 2006 and the Suruhanjaya Perkhidmatan Air Negara (SPAN) Act 2006. The SPAN Act was enforced on 1 February 2007 and paved the way for the formation of SPAN to regulate water supply and sewerage services. WSIA came into force on 1 January 2008 and repeals the Sewerage Services Act 1993 and relevant state water supply enactments.

SPAN possesses executive power over water supply and sewerage services and regulates all water supply operators and sewerage treatment operators. To ensure sufficient water supply, state water operators are licensed as asset light licensees and are required to prepare a three-year business plan under Section 30 of WSIA. This plan will help in setting a targeted key performance index (KPI), including reducing non-revenue water (NRW). It must also ensure the security, integrity, and safety of water supply systems.

In terms of sewerage services, SPAN regulates Indah Water Konsortium (IWK) in several ways. SPAN ensures that IWK complies with the legal, regulatory, and operational standards set for wastewater and sewerage services. This includes monitoring IWK’s performance in terms of service delivery, treatment standards, and environmental protection. IWK is also required under Section 34 of WSIA to ensure the security, integrity, and safety of sewerage systems. IWK also has power and duties under Sections 57 to 67 to ensure sustainable and reliable sewerage systems and services in the country.

Besides WSIA, SPAN also sets standards, guidelines, and regulations for the operation of sewerage systems in Malaysia. IWK is required to follow these guidelines in managing wastewater treatment and the maintenance of infrastructure. Essentially, SPAN ensures that IWK maintains high service standards, such as minimizing disruptions in sewage services, maintaining infrastructure, and addressing consumer complaints. If IWK fails to comply with the regulatory framework, SPAN has the authority to enforce penalties, take corrective actions, and even impose fines.

SPAN has also published two important regulations to ensure clean water and sanitation. The Water Services Industry (Prohibited Effluent) Regulations 2021 set the effluent standards to be met under the normal operation of a sewage treatment plant. Section 3 (1) prohibits any person from discharging or allowing for the discharge of any prohibited effluent in the schedule into any public sewer or public sewage treatment plant without SPAN’s approval. This includes any pollutants, including oxygen-demanding pollutants, in sufficient quantity of flow or concentration, that cause interference in sewage treatment plants. It also monitors any discharge and substance that passes through sewage treatment plants and breaches the Environmental Quality (Sewage) Regulations 2009, as well as any discharge or substance that affects the disposal of sewage sludge as an organic compound and solid or viscous substances which may obstruct the flow in a sewer.

These regulations are rather extensive in terms of pollution coverage. However, the sources of pollution may come from activities licensed by other agencies such as local councils. Thus, other agencies should impose similar requirements in the licensing conditions approved by them. Another problem to be solved is the fact that the regulation only applies to licensed sewage treatment plants under WSIA. It does not monitor septic tanks in traditional villages or old housing estates.

Besides the regulation on effluents, the Water Services Industry (Desludging Services) Regulations 2021 was established following the mandatory requirement of the desludging of septic tanks under S. 44 of WSIA. Regulation 2 (1) requires the service licensee operating and maintaining a public sewerage system to desludge septic tanks once every twenty-four months for a septic tank situated within the boundary of any local authority area and once every thirty-six months for a septic tank situated outside of the boundary of any local authority area [86].

A service licensee who fails to desludge septic tanks in accordance with the frequencies prescribed under sub-regulation (1) commits an offense under subsection 44 (2) of WSIA. The only challenge remaining to enforcing these regulations is the cost of desludging. It is thus important that a new mechanism be proposed by the state and local governments, such as a subsidy or cash rebate for desludging. Alternatively, business entities can sponsor these services as part of their corporate social responsibility (CSR).

In terms of wastewater reclamation, IWK embarked on its first reclamation project in 2021 with the establishment of the water reclamation plant (WRP) in Setia Alam Selangor and now yields 4 million liters daily for the industrialized state of Selangor [86]. Be that as it may, due to the division of duties between water supply operators and sewerage service operators under WSIA, IWK may not be able to sell reclaimed water to consumers. Under WSIA, IWK is licensed as a sewerage service operator, while water supply is licensed to the state water supply operator, Air Selangor. Hence, IWK must partner with Air Selangor to sell and supply reclaimed water. IWK is currently negotiating with other state water supply operators to have similar joint ventures.

5. Conclusions

Reclaimed wastewater management in Indonesia presents both challenges and opportunities. Despite existing regulations and implementation efforts, gaps in policy enforcement, infrastructure development, and public awareness remain significant obstacles. The regional analysis of Western, Central, and Eastern Indonesia highlights disparities in governance, technological adoption, and resource distribution.

International legal frameworks, including environmental sustainability principles, human rights obligations, and the “polluter pays” principle, provide a further strong foundation for improving wastewater management. Case studies from Singapore illustrate how advanced treatment technologies, centralized systems, and well-enforced regulations can enhance wastewater reuse and sustainability. Meanwhile, in Malaysia, although duties between water supply operators and sewerage treatment operators are separated by the law, it does not stop IWK from creating joint ventures with state water supply operators in water reclamation projects.

Indonesia must strengthen its legal and institutional frameworks to promote wastewater reclamation. Key steps include adopting international best practices, investing in centralized treatment facilities, ensuring regulatory compliance, and increasing public engagement in sustainable water management. By taking these measures, Indonesia can mitigate environmental risks, protect public health, and contribute to global efforts in addressing water scarcity.