The statistical data pertaining to the management of wastewater in Kabul city is notably deficient. The present study aimed to examine and tackle the prevailing conditions and significant obstacles associated with the management of domestic wastewater in residential localities. Furthermore, to propose sustainable remedies. The adopted methodology entails the utilization of questionnaires, field observation, and the examination of pertinent documents from relevant stakeholders. The findings suggest that a majority of households, exceeding 50 %, lack access to upgraded sanitation facilities. There are currently no functional wastewater treatment plants, with the exception of Macroyans' facilities, which are not operating effectively. Moreover, the absence of a suitable drainage infrastructure is evident. The improper treatment of domestic wastewater results in the discharge of nearly 100 % of it into the environment, leading to significant health and environmental concerns such as groundwater contamination, unpleasant odors, and adverse impacts on biodiversity. The prevalent illnesses include diarrhea, malaria, cholera, and typhoid fever. The primary obstacles associated with managing domestic wastewater pertain to inadequate sanitation infrastructure, insufficient wastewater treatment facilities and drainage systems, inadequate governmental oversight, limited public engagement, and an absence of a durable framework for sustainable wastewater management. The sustainable management of wastewater in Kabul city is contingent upon several factors, including the implementation of decentralized wastewater treatment technologies, the enforcement of relevant legislation, the decentralization of planning and budgeting to local institutions, the involvement of the public, planners, and policy-makers at all levels, and the establishment of a sustainable wastewater management framework. These elements are crucial in addressing the current circumstances and challenges associated with domestic wastewater management in the region.
The present discourse centers on the topic of domestic wastewater and its sustainable management. Specifically, the focus is on the implementation of decentralized systems that can contribute to the realization of a circular economy.
Keywords: domestic wastewater, sustainable wastewater management, decentralized system.
Introduction
Domestic wastewater refers to the effluent originating from residential sources, including but not limited to toilets, baths, laundry, food preparation, and kitchen cleaning activities. Domestic wastewater refers to the wastewater generated from human activities in households. The composition of the substance in question comprises a substantial quantity of suspended and floating particulate matter, including but not limited to excrement, paper, vegetable remnants, and harmful contaminants such as pathogenic microorganisms (Mara, 2004). The microbiological constituents present in unprocessed household wastewater comprise of bacteria, protozoa, and viruses. Untreated domestic wastewater comprises two distinct categories of bacteria, namely beneficial and harmful. Beneficial microorganisms that facilitate the degradation of waste products are employed in the treatment of wastewater in various plants. Various illnesses in humans, including typhoid fever, bacillary dysentery, and tetanus, are caused by harmful or pathogenic bacteria. According to Arcadio and Gregoria's (2003) research, individuals infected with hepatitis are found to emit between 10,000 to 100,000 transferrable particles of viruses per gram of fecal matter. In general, the two types of domestic wastewater are distinguished as follows: Greywater refers to the domestic wastewater that is collected from sources such as bathrooms, showers, bathtubs, dishwashing, and clothes washing, while excluding water from toilets. Typically, greywater comprises of substances such as toothpaste, shampoo, soaps, oil, and food particles. The direct reuse of greywater is a viable option for various purposes such as irrigation, toilet flushing, and domestic heating. The term «black water» refers to the wastewater that is specifically collected from toilets. According to Andersson et al. (2016a), black water typically comprises of two components, namely brown water (comprising of human feces and flush water) and yellow water (comprising of urine). The composition of brown water, also known as human feces, includes 13 % nitrogen and 28 % phosphorus. Urine is composed of 69 % of total nitrogen and 40 % of total phosphorous. Phosphorous fertilizers are derived from non-renewable sources and the insufficiency of phosphorous nutrients has a detrimental impact on agricultural yields. According to Mulec et al. (2017), it is estimated that around 22 % of the current phosphorous nutritional needs can be met by utilizing all the phosphorous present in the black water and returning it to the agricultural land. Unmitigated discharge of household effluent poses a variety of economic risks, such as reduced output in agriculture and industry, as well as heightened financial strain on healthcare. The devaluation of properties in close proximity to polluted water sources and the potential impact on tourism can be attributed to the deterioration of water quality, as tourists tend to prioritize access to unpolluted water sources. Moreover, the absence of treatment of domestic wastewater results in adverse impacts on the aesthetic appeal of the environment, recreational activities, and the emergence of unpleasant odors and other ecological challenges, as noted by Sancho et al. (2015). The absence of proper treatment of household wastewater poses a significant challenge to the attainment of sustainable water management, leading to adverse environmental, economic, and health consequences in both the short and long term. According to Edokpayi et al. (2017), pathogenic microorganisms that can lead to a range of illnesses, such as bacteria, protozoa, viruses, fungi, and parasitic worms, have been detected in domestic wastewater by researchers. The absence of appropriate treatment of household wastewater results in significant ecological concerns, including eutrophication and the release of Greenhouse Gas (GHG) emissions in the form of CH4 (methane) and N 2O (nitrous oxide) (Libardi et al., 2019). The absence of proper treatment of household wastewater results in an estimated annual mortality rate of 1.5 million children. As per the World Bank, it has been estimated that untreated domestic wastewater results in a global loss of 260 billion dollars annually (Cheng et al., 2018). SDG 6 prioritizes objectives 6.2 and 6.3, which pertain to hygiene and water quality, while SDG 3, which concerns good health, is primarily associated with sanitation. The management of wastewater is a crucial factor in achieving various sustainable development goals, including but not limited to poverty reduction, economic growth, education, gender equality, and the development of sustainable cities (World Health Organization, 2018). Water holds a crucial position in the circular economy due to its paramount importance and indispensability as a primary resource for production. Consequently, within the context of the circular economy, the treatment of wastewater constitutes a crucial component of water resource management. In a circular economy, it is imperative that water retains its complete value following each utilization. According to Flores et al. (2018), the utilization of domestic wastewater for agricultural purposes can lead to enhanced productivity and increased production. According to Moretti et al. (2019), the utilization of domestic wastewater can serve as a means for societies to address the pressing issue of safe water resource availability, thereby providing valuable and essential solutions. The retrieval of both raw materials and energy plays a crucial role within the framework of the circular economy. The excreta of humans, comprising fecal matter and urine, possess a high concentration of nutrients and can serve as a valuable source of agricultural fertilizer. According to Malila et al. (2019), the utilization of urine and feces in this manner serves to safeguard natural water sources against the negative effects of eutrophication and contamination. It is widely acknowledged that the availability of alternative sources of water is insufficient to ensure a secure water supply. The rise in population, coupled with urbanization and industrialization, has led to a growing scarcity of water. Consequently, there is a higher likelihood of potable reused water being utilized as a resource to supplement drinking water supplies (Tortajada and Nambiar, 2019). Various types of materials such as bioplastic, cellulose, phosphate, alginate-like substances, and biomass have the potential to be recovered from wastewater. The retrieval of energy and raw materials from wastewater serves to enhance water quality and bolster the circular economy. According to Leeuwen et al. (2018), the Netherlands generates an annual revenue of 230 million from resources recovered from wastewater. The city of Kabul serves as the capital of Afghanistan and has been identified as one of the rapidly expanding urban centers globally. According to Ahmadi and Kajita (2016), the estimated population of Kabul was approximately 4 million in 2012. The city of Kabul is among the most destitute urban areas in terms of access to clean water delivery and adequate hygiene services on a global scale. The populace of Kabul metropolis lacks access to a comprehensive system for treating general wastewater. The surface water and groundwater resources within Kabul city are currently facing a significant risk. This is primarily due to unsustainable and uncontrolled groundwater abstractions, as well as the presence of biological and chemical pollutants within both surface and groundwater sources. According to Zaryab et al. (2017), microbiological assessments have revealed that approximately 58 to 70 % of the deep wells in the city are contaminated with fecal (coliform) bacteria.
The present study comprises a literature review on the topic of sustainable wastewater management systems.
According to Laugesen (2010), an effective wastewater management system that is sustainable should include a well-designed wastewater collection system, sustainable treatment methods, energy-efficient facilities, a suitable system for recovering raw materials, and appropriate legislative and financial structures. A sustainable system can be defined as one that safeguards public health, is economically feasible, maintains technical and institutional consistency, provides environmental protection, and is socially acceptable. According to Capodaglio et al. (2016), ensuring environmental quality protection, nutrient reutilization, and preservation of natural resources are imperative components of a sustainable wastewater treatment system. The implementation of a sustainable wastewater management system plays a crucial role in safeguarding society, economy, and environment against the adverse effects of wastewater. In addition, sustainable technologies for treating wastewater take into consideration the potential effects of their operations on both public health and the environment, as noted by Popovic and Kraslawski (2018). The implementation of sustainable wastewater management systems has the potential to enhance soil quality, increase agricultural productivity, and provide more efficient protection of ecosystems. Moreover, it is observed that decreasing healthcare expenses leads to the emergence of fresh employment prospects and entrepreneurial ventures. According to Andersson et al. (2016b), the attainment of Sustainable Development Goals (SDGs) is unattainable in the absence of a viable and enduring wastewater management framework. The implementation of sustainable wastewater treatment systems plays a crucial role in mitigating the adverse effects of water pollution and greenhouse gas emissions. According to Sanabria et al. (2018), wastewater management systems that are sustainable have the ability to generate energy while simultaneously reducing water contamination, air pollution, and greenhouse gas emissions. According to Wirawan et al. (2018), the primary obstacles to establishing a sustainable wastewater treatment system include insufficient public participation and awareness, reluctance of communities to bear the costs, challenges in securing suitable land, inadequate adaptation of technology, insufficient involvement of privately-owned businesses, and the role and commitments of the government. Frequently, inadequate conditions and disarray in wastewater management systems can be attributed to a deficient governance framework. According to Kjellén (2018), investing in institutional capacity may be more beneficial for achieving consistent and enduring growth in wastewater management as opposed to investing directly in physical infrastructure.
Methodology
The data was gathered from both primary and secondary sources. The two main types of primary data sources utilized in research are field observation and questionnaires. Secondary data is obtained from various sources such as books, journals, reports, maps, and conference proceedings. Furthermore, there are governmental and non-governmental organizations (NGOs) located in the city of Kabul. The survey instrument utilized in this research was derived from Ehsas' (2013) work. A survey instrument comprising of closed-ended questions was administered to a total of 151 participants. The survey participants were comprised of individuals or family members residing in residential areas within the city of Kabul. The questionnaire demonstrated high levels of reliability and consistency, resulting in precise and consistent responses from all survey participants. A thorough field investigation was carried out to gather data on the present state of domestic wastewater management, encompassing aspects such as wastewater drainage, sanitation facilities, domestic wastewater disposal, water sources, and the assessment of potential hazards to public health and the environment. The Public Health Directorate of Kabul city conducted a visit to investigate cases of illnesses that are associated with water contamination.
The present section presents the results obtained from the study and provides a discussion of the findings.
The survey was structured into distinct categories pertaining to sanitation infrastructure, wastewater treatment systems, wastewater elimination, urban planning reform, waterborne health and environmental concerns, potable water resources, citizen participation and cost recovery and billing matters, potential for wastewater reuse, and the underlying factors contributing to the present state of domestic wastewater management.
I. The present state of domestic wastewater management in Kabul City is the subject of inquiry.
Various types of toilets are utilized by households residing in Kabul city's residential areas, including basic pit latrines, pit latrines equipped with a flush, pour-flush latrines, and traditional flush latrines. The field study revealed that the discharge of yellow wastewater from toilets onto the streets poses significant health and environmental risks. The construction of pit latrines by the homeowners lacks professional standards. Furthermore, it should be noted that the pit latrines lack durability as they are not constructed using materials such as concrete, bricks, fiberglass, and stainless steel. According to the joint report by UNICEF and WHO in 2018, pit latrines lacking platforms, constructed from non-durable materials, and exhibiting poor ease of cleaning, do not meet the criteria for improved sanitation facilities. As per the available data, a significant proportion exceeding 50 % of households residing in Kabul's residential areas continue to lack access to improved toilet facilities. Graham and Polizzotto (2013) contend that the utilization of pit latrines is associated with a range of health and ecological issues, including the contamination of groundwater by microbiological and chemical pollutants. It has been observed by scholars that unsafe concentrations of chemicals, bacteria, and viruses can be found at distances of up to 25m, 26m, and 50m from pit latrines. According to the survey results, a majority of residential households, specifically over 70 %, utilize cesspool systems while approximately 27.2 % rely on septic tanks. Inadequately constructed cesspools have been identified as a primary contributor to groundwater contamination in Kabul city. This is due to the fact that homeowners often lack the necessary knowledge and resources to construct them properly. Furthermore, it is common for cesspools to lack proper protection, thereby facilitating the ingress of wastewater that can lead to the spread of illnesses. As per the findings of the Ministry of Rural Rehabilitation and Development (2015), the deep wells situated in Kabul city are contaminated both biologically and chemically. Furthermore, as per the report's findings, it has been indicated that in certain regions, the water from deep wells is not potable. The cesspool system is employed for the treatment of black water. In general, the effluent generated in cesspools exhibits low quality and typically infiltrates the adjacent soil, leading to groundwater pollution (Surinkul et al., 2017). The data suggests that residential households lack access to adequate wastewater treatment infrastructure, resulting in approximately 100 % of domestic wastewater from residential areas being discharged into the environment without proper treatment. With the exception of Macroyans, a wastewater treatment facility that only receives 5 % of the total wastewater output of Kabul city, there are no other such plants located in residential areas. The Macroyans wastewater treatment plant does not employ any chemical or biological treatment methods. Upon completion of the physical treatment procedure, the wastewater is discharged directly into the Kabul River. Furthermore, the absence of a suitable drainage infrastructure results in the accumulation of wastewater, which obstructs streams or is discharged directly into the Kabul River. Figure 1 depicts the current state of domestic wastewater management and inadequate drainage systems in Kabul city. A significant proportion of households experience episodes of diarrhea, malaria, typhoid fever, and cholera. The Kabul City Directorate of Public Health (2018) reported that during the initial quarter of the solar year (which corresponds to the Spring season in Afghanistan), a total of 31,350 cases of diarrhea in children under the age of five and 768 cases of Malaria were recorded exclusively in public hospitals located within the city of Kabul. In addition, the generation of wastewater in Kabul city is attributed to various environmental issues, including contamination of surface and groundwater, malodorous emissions, proliferation of flies and mosquitoes, and degradation of aesthetic appeal. Groundwater sources exclusively provide the drinking water supply in Kabul city. Groundwater is utilized for all domestic purposes, including agriculture, in Kabul city due to the absence of wastewater reuse. A significant proportion, exceeding 60 %, of the populace remains unaware of the potential utilization of reclaimed wastewater for agricultural and indoor applications, including but not limited to toilet flushing. The results of the current survey suggest that households residing in residential areas express contentment in providing both financial and non-financial contributions, such as labor for construction and repair, towards domestic wastewater management initiatives. The level of affordable funds is contingent upon the monthly incomes of households. Families with higher incomes are capable of affording greater amounts, while those with lower incomes are content with paying a lesser sum for services. The survey analysis indicates that the primary factors contributing to prevailing domestic circumstances are inadequate government accountability, insufficient availability of appropriate land, and insufficient involvement of the community. The concept of responsibility serves as a powerful motivator for both societal and organizational behavior, guiding them towards positive outcomes. Assuming responsibility is a crucial aspect of engaging in international partnerships, governmental entities, and service providers to ensure the provision of sustainable water supply and sanitation services. Decentralization of planning and budgeting to local societies and associations is a favorable and constructive strategy for enhancing responsibility in wastewater management. The UN Millennium Project (2005) posits that the decentralization of planning and budgeting serves to enhance the influence of the public over policy and decision-makers, by means of social norms, communal appraisal, and electoral processes. Naughton and Hynds (2014) posit that effective public engagement is crucial for the successful involvement of society in wastewater management. Enhancing public commitment could be achieved through increased community awareness regarding the potential hazards of wastewater to both the environment and drinking water.
II. The primary obstacles associated with the management of domestic wastewater in Kabul city are the focus of this analysis.
The primary obstacles to effective domestic wastewater management in Kabul city include inadequate sanitation facilities, insufficient wastewater treatment infrastructure and inadequate drainage systems, limited governmental accountability and inadequate public engagement, and the absence of a viable and sustainable framework for wastewater management.
Resolutions
A majority of the populace residing in Kabul city lacks access to improved sanitation facilities. The majority of individuals utilize pit latrines, which are constructed from materials that lack durability, such as concrete, bricks, fiberglass, and stainless steel. This can lead to contamination of underground water sources. Composting toilets represent a viable and enduring resolution to this predicament. Composting toilets are a financially and socially accessible option that offers enhanced sustainability and environmental benefits, while also eliminating the need for water and electricity. Composting toilets possess the potential to offer an economical resolution for enhanced agricultural productivity, in conjunction with heightened nourishment and the mitigation of health and environmental consequences stemming from unenclosed defecation (WWAP, 2017). Waterless composting toilets serve as a viable substitute in regions where a centralized wastewater system is not feasible due to the absence of standard urban infrastructure, water supply, and electricity, as stated by Nasri et al. (2019). Composting toilets are known to provide benefits in terms of safeguarding public health and mitigating environmental pollution. coli bacteria can be effectively controlled through the use of certain antimicrobial agents, as demonstrated in their research findings. The absence of Escherichia coli and Salmonella during the composting process can be attributed to the alkaline conditions. The results of the present survey indicate that insufficient wastewater treatment facilities and inadequate drainage systems pose significant obstacles to the management of domestic wastewater in the city of Kabul. The primary factors contributing to this issue include accelerated urbanization and population expansion, economic and institutional challenges, insufficient technical expertise, and limited access to water and electricity resources. Hence, the deployment and utilization of a decentralized wastewater system represent a suitable and enduring approach towards managing household wastewater in the urban area of Kabul. Centralized systems have proven to be ineffective in various instances in several developing Asian countries, primarily due to their exorbitant cost. According to the 8th World Water Forum in 2018, there is a strong belief that decentralized wastewater management systems are a viable and appropriate alternative to centralized systems in several Asian nations. One of the primary obstacles to effective domestic wastewater management in Kabul city is the inadequate assumption of government responsibilities and a lack of public participation. The concept of responsibility is a powerful motivator that effectively guides both societies and organizations towards desirable outcomes. The embracement of international associations, government organizations, and service suppliers is crucial in ensuring the provision of sustainable sanitation services and water supply. This necessitates a sense of responsibility on the part of all stakeholders involved. Decentralization of planning and budgeting to local societies and associations is a favorable and helpful approach for enhancing responsibility in wastewater management. The UN Millennium Project (2005) posits that the decentralization of planning and budgeting enhances the authority of the public over policy and decision-makers, by means of social norms, communal evaluation, and voting. The legal framework pertaining to wastewater management is characterized by two crucial components, namely public participation and access to information. The Aarhus Convention, also known as the UNICEF Convention on Access to Information, Public Participation in Decision-making, and Access to Justice in Environmental Matters, along with its accompanying Protocol on Pollutant Release and Transfer Registers (PRTRs), presents a comprehensive set of procedural guidelines for governments to effectively involve the public in sustainable development efforts. The involvement of the public is a crucial factor in enhancing and implementing environmental legislation. The United Nations Environment Program (2015) asserts that access to statistical data is a crucial factor for enabling effective public engagement in decision-making processes and for issuing alerts regarding pollution. The lack of a robust and sustainable framework for managing wastewater poses a significant obstacle to the effective management of domestic wastewater in Kabul city. The current WASH policy, originally designed for the timeframe of 2010 to 2020 and revised in 2015, lacks a pertinent and well-defined framework for the treatment of domestic wastewater. The establishment of a sustainable framework and initiative for managing domestic wastewater is imperative for effective management of wastewater in Kabul city. The Waste to Wealth initiative framework has been identified as a viable solution for managing domestic wastewater in Afghanistan, particularly in the city of Kabul, given the current challenges and circumstances surrounding this issue. The Waste to Wealth initiative in Uganda utilizes a framework that capitalizes on potential post-treatment revenue and aids in the reduction of environmental pollution caused by human waste. The anaerobic process of digesting domestic wastewater has the potential to generate valuable resources that would otherwise have a detrimental impact on the environment and the associated ecosystem services, such as fisheries. According to UNU-INWEH (2013), the anaerobic digestion of human and solid waste in Uganda generates by-products that are utilized to produce biogas and agricultural fertilizers. These by-products are deemed more valuable than conventional sludge. The city of Kampala, which serves as the capital of Uganda, has garnered international acclaim for its innovative approach to integrated water management, positioning it as a trailblazer in the African context. Kampala is implementing a holistic approach at the municipal level to enhance the management of wastewater and fecal sludge, with the aim of advancing the principles of a circular economy. The Kampala Sanitation project encompasses the execution of a wastewater treatment facility and the rehabilitation of the sewer system. Furthermore, the utilization of biogas production and subsequent electricity generation will serve as a means to supply energy to the treatment plant, with any excess energy being transmitted back to the power grid. The collaboration between the National Water and Sewerage Corporation and Kampala Capital City Authority aims to expedite the progression of Kampala's shift towards sustainable wastewater management. These two entities have effectively engaged various urban stakeholders, such as residents, in devising remedies. The establishment of call centers for septic tank emptying and the implementation of decentralized wastewater treatment systems are considered essential components of this methodology, as outlined in the Wastewater Report of 2018.
III. Conclusion
At present, over 50 % of households residing in Kabul city's residential areas lack access to improved toilet facilities. The residential areas of Kabul City lack a centralized or decentralized system. Consequently, an estimated 100 % of domestic wastewater is discharged into the environment without undergoing appropriate treatment. The incidence of health issues is on the rise in Kabul city, with a particular increase in ailments such as diarrhea, malaria, typhoid, and cholera. Furthermore, the discharge of wastewater has been found to result in a range of environmental issues, including contamination of surface and groundwater, emission of unpleasant odors, proliferation of flies and mosquitoes, and degradation of aesthetic quality of the environment. The primary obstacles include the absence of adequate sanitation facilities, insufficient wastewater treatment infrastructure and drainage systems, inadequate government oversight, a lack of public engagement, and an absence of a sustainable framework for managing wastewater. In light of the prevailing circumstances and challenges associated with domestic wastewater management, composting toilets and decentralized wastewater treatment technologies have emerged as the most viable and sustainable solutions for managing wastewater in Kabul city. Furthermore, the sustainability of wastewater management in Kabul city can be enhanced through the enforcement of legislative measures, dissemination of information and guidelines to the general public, decentralization of planning and budgeting to local institutions, establishment of a research center, engagement of stakeholders at all levels, and development of a sustainable wastewater management framework.
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