A Cost Benefit Analysis of Water Recycling in Manufacturing Industries: a Case Study of the East African Breweries Limited, Kenya
Abstract and Figures
Water recycling offers a potential solution for water scarcity and way for
manufacturing industries save on water purchases and wastewater disposal. This is
true for large water consumer like East African Breweries Limited (EABL), whose
operations are highly dependent on reliable water supply. While water recycling has
become a popular concept, little information exists on the costs and benefits of
industrial water recycling and the reasons for the reluctance in its adoption.
Similarly, Kenya‘s policy and regulations on water recycling are still not widely
understood. The aims of this study goal were to compare the costs of treating and
recycling water in at EABL to its benefits, shed new light on challenges in greywater
recycling at EABL, and evaluate Kenya's regulatory framework on water recycling
in the manufacturing sector. This case study carried out between March and July
2016 used both qualitative and quantitative data from primary and secondary sources
collected through key informant interviews and literature review. The avoided cost
method was used to determine the benefits, while the costs were obtained through
data from key informants. The Net Present Values (NPV), benefit cost ratio (BCR)
and Internal Rate of return (IRR) were tests used to assess the viability of water
recycling at the brewery. The analysis of the data from the interviews and literature
review informed the assessment of the challenges and Kenya's regulatory framework
industrial water recycling. Results indicated that greywater recycling was
economically viable. In fact, the avoided costs by EABL were US 604.79 Million and US 3.11, US 4.01 per invested dollar for 10%, 25% and 50% recycling, respectively
according to the Benefit Cost Ratio (BCR). According to the IRR test, all the recycling capacities were viable regardless of inflation rates. The study also revealed
that the high cost of water recycling technologies and lack of incentives were the
biggest the challenges that hinder industrial water recycling. Surprisingly, the study
found that water recycling was inadequately addressed in water related regulations
and there was no institution with the mandate of spearheading water recycling in the
manufacturing and domestic sector. In addition, Kenya's regulatory framework
leaned towards control of effluent rather than the reduction of wastewater production
and promotion of water recycling. The conclusion was that water recycling at EABL
was economically feasible for all capacities evaluated in the study. There was need
to address these challenges through the reform of the regulatory framework,
allocating water recycling responsibility to an institution and awareness creation to
improve acceptable of recycled water.
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... The inability to realise significant return on the substantial upfront cost of installation and the long payback period of water conservation systems and technology have led to the discounting of the economic benefits of these systems and measures. Therefore, there is a need for costbenefit analysis of water conservation systems in households for achieving a larger impact in reducing water scarcity in Nairobi (Wakhungu 2016). Recent trends in availability, demand, and price of water coupled with the growing number of economic and regulatory incentives for use of these systems in buildings indicate a serious need for a more detailed cost-benefit analysis of water conservation systems installed in household buildings. ...
... Sustainable Development Goal 6 supports water recycling and treatment technologies with countries like Australia, the UK, Canada, and the USA upscaling water recycling. Locally, the lack of regulations on recycled water has hindered progress in water recycling efforts (Wakhungu 2016). The rainwater harvesting system collects, conveys, and stores rainwater for later use (Amani 2013). ...
... If the benefit is squarely based on the water consumption savings, the benefit of the RWH system is small and economically unfeasible (Kartolol and Kusumawati 2017). A study by Wakhungu (2016) recommended CBA be carried out in households to complement her findings that CBA of wastewater recycling in manufacturing industries is feasible. However, there is still only slow adoption of these technologies in industries due to inadequate information on benefits and ambiguity in their challenges. ...
Cost–benefit analysis of installed water conservation systems (piped water storage, water recycling, and rainwater harvesting) is important in management of water resources in urban areas. This study analysed water conservation systems installed in households in Nairobi County using 200 households’ questionnaires. Benefit–cost ratio analysis indicated that the piped water storage system and rainwater harvesting system were viable with benefits at 2.80 and 2.03, respectively, while the water recycling system was not viable at 0.80. This study recommends installation of piped water storage and rainwater harvesting systems for quality, quantity, and reliable water to be availed in households within viable economic costs.
... As an example, the sites mentioned by Mathu et al. (2014), while difficult to evaluate since the data is not spatially presented, coincide with regions where land subsidence is occurring. Furthermore, EABL (point f) installed a water recycling plant towards the end of 2007, which dramatically reduced the water demand (Wakhungu et al. 2017;EABL 2011). Hence, this may explain why no subsidence has been observed between 2017 and 2021. ...
Nairobi, Kenya’s capital city, is one of the fastest-growing cities on the continent. The rapid expansion of human activities has resulted in the overexploitation of natural resources, such as water. In the past, Nairobi had been identified as a vulnerable area to environmental hazards, such as land subsidence. Due to the lack of a functioning deformation-monitoring system in Kenya, the subsidence in Nairobi has yet to be empirically quantified. In this paper, we report the results of the first InSAR-based spatial assessment of land subsidence in Nairobi. Our analysis indicates both localized and regionalized subsidence in several locations in the west and north west of Nairobi. The largest deforming unit in Nairobi’s western part is subsiding at approximately 62 mm/yr. Land subsidence can be attributed to groundwater overexploitation because it coincides with regions with the highest decline in groundwater levels. However, subsidence can also be attributed to consolidation associated with rapid urbanization in other areas such as east of Nairobi. This evaluation corroborates previous hydrogeological investigations which indicated that Nairobi was at risk of subsidence, contributing to flooding in some residential areas. The findings will help guide future decision-making in several agencies as well as provide an effective tool for planning mitigation measures to prevent further subsidence. A few of these include regulating borehole drilling, planning of roads and buildings, and locating groundwater observation wells. In addition, the observed significant land subsidence stresses the need for an updated geodetic reference system. Since Nairobi plays a significant role in the economy of Kenya, the effects of subsidence may be devastating and it is imperative that steps are taken to minimize their impact.
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Public involvement is critical to the successful implementation of reclaimed water reuse programs. Based on the participatory research method, we studied the attitudes of the stakeholders who are involved in reclaimed water reuse in Beijing, China. Results showed that the general public’s knowledge on water resources was poor, while their awareness on reclaimed water reuse was high. The general public showed a strong acceptance of non-contact and non-potable reclaimed water reuse, but their acceptance of the three major water reuse types of river water supplement, park water supplement, and agriculture irrigation was not high. The beneficial use of reclaimed water was admired by water resource managers, industrial sectors, and researchers, and these stakeholders strongly supported the advancement of reclaimed water reuse. However, some of the stakeholders showed concerns about the potential risks from reclaimed wastewater reuse. Among them, risks from waste water treatment facilities were the biggest concern. Stakeholders’ perception of reclaimed water was influenced by their social-economic attributes. This study will enrich the current survey findings on public perception of reclaimed water reuse, particularly in developing countries.
As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and the chances of tapping new water supplies for metropolitan areas are getting more difficult, if not impossible. As a consequence, existing water supplies must go further. One way to achieve this objective is by increased water reuse, particularly in supplementing municipal water supplies. Although water reuse offers many opportunities it also involves a number of problems. A significant cost for nonpotable water reuse in urban areas is associated with the need to provide separate piping and storage systems for reclaimed water. In most situations, the cost of a dual distribution system has been prohibitive and thus, has limited implementation for water reuse programs. The solution to the problem of distribution is to implement direct potable reuse (DPR) of purified water in the existing water distribution system. The purpose of this paper is to consider (a) a future in which DPR will be the norm and (b) the steps that will need to be taken to make this a reality. Following an overview, the rationale for DPR, some examples of DPR projects, technological and implementation issues, and future expectations are examined.
As demands for freshwater withdrawals continue to escalate in water-stressed regions, negative consequences of alterations to natural systems will become ever more severe. Habitat restoration projects may mitigate some of these challenges, but new strategies will be needed to maintain or enhance ecosystem health while simultaneously meeting human needs. Recycled water is a reliable water source that can be used both directly and indirectly to renew degraded urban stream ecosystems. In this review, aspects of hydrology, water quality, and ecosystem services in relation to water reuse for urban stream renewal are evaluated to identify research needs and design considerations for new systems. Use of recycled water for streamflow augmentation in urban areas remains largely unexplored scientifically, despite its potential widespread applications among water and
wastewater utilities. To move this innovative concept toward implementation, experimental studies in stream microcosms are needed to examine ecological response to coupled modification of both hydrology and water quality. Appropriate methods for selecting potential sites for urban stream renewal should be identified, along with ecological and economic metrics for evaluating success. Examples of projects in California, Japan, Israel, and Spain are used to identify different management scenarios. However, design criteria from both successful and unsuccessful case studies require additional review and synthesis to develop robust guidelines for recycled water use in urban stream renewal. Motivations for past stream renewal projects include regulatory requirements for water quality improvement and endangered species protection, although these motivations alone may not be enough to facilitate widespread adoption of reusing wastewater for ecosystem enhancement. Consequently, future project designs should include more detailed ecosystem service valuations to describe broader societal benefits and attract the attention of government agencies and private organizations that ultimately make the choice between environmental perturbation or enhancement.
An unbiased forecast of the terminal value of a portfolio requires compounding of its initial value at its arithmetic mean return for the length of the investment period. Compounding at the arithmetic average historical return, however, results in an upwardly biased forecast. This bias does not necessarily disappear even if the sample average return is itself an unbiased estimator of the true mean, the average is computed from a long data series, and returns are generated according to a stable distribution. In contrast, forecasts obtained by compounding at the geometric average will generally be biased downward. The biases are empirically significant. For investment horizons of 40 years, the difference in forecasts of cumulative performance can easily exceed a factor of 2. And the percentage difference in forecasts grows with the investment horizon, as well as with the imprecision in the estimate of the mean return. For typical investment horizons, the proper compounding rate is in between the arithmetic and geometric values.
1-1 Overview Kenya is located in Eastern part of Africa and has a total area of 582,646 Sq.km. 80% of Kenya's land area is semi-arid and only 20% is arable land. Kenya's capital city, Nairobi is centrally located in the country and covers an area of 684 square kilometres, and holds a population of 3.3 million people. Kenya, like many other developing countries in Africa, is experiencing rapid urbanization growth (UN Habitat, 2008, p.102). Many cities and towns have grown in population size and also expanded spatially to form huge metropolitan regions. Metropolitan regions do present huge development opportunities. The rapid urbanization also generates a lot of problems and challenges – economically, socially and environmentally. Nairobi is one such metropolitan region in Kenya. What potential opportunities, problems and challenges face this new emerging metropolitan region? What is the way forward and what are possible solutions? This is the focus of this paper. 1-2 Defined Boundary of Metropolitan Region Nairobi metropolitan region covers approximately 32,000 km 2 – Figure 1-1. This covers 15 No. local authority areas – City Council of Nairobi (684 km 2); County Councils of Kiambu, Olkejuado, Masaku and Thika; Municipal Councils of Ruiru, Thika, Kiambu, Limuru, Mavoko, and Machakos; and Town Councils of Karuri, Kikuyu, Kajiado, and Kangundo (Ministry of Nairobi Metropolitan Development, 2009, p. 38) .
The integrated study of energy and urban systems has recently become a critical component of sustainability research and policy. Increasing urbanization of human societies combined with intense energy demands of modern economies have driven a recognition that sustainable practices require a systems approach to both the study and application of sustainability principles. Urban metabolism has emerged as a leading methodology for quantifying energy consumption and use patterns in urban environments. Though typically applied as a method of accounting for total energy and materials inputs and outputs into cities, its interdisciplinary history and methods allow urban metabolism to be expanded in ways that will allow more comprehensive and integrated assessment of the patterns and processes of urban energy systems. In this article, we review the concept of urban metabolism—including its two typical approaches: mass balance and “emergy” methods—and offer a means to expand urban metabolism into a platform that incorporates socioeconomic analysis, policy analysis, and additional quantitative methodologies (such as life cycle assessment). This expanded urban metabolism framework is more comprehensive analytically and builds upon the documented capacity of traditional urban metabolism to account for total energy and materials flows of cities to provide an integrated platform for analysis of both energy patterns and the causal processes that govern energy in contemporary cities.
Waste management is viewed as part of a generation, collection and disposal system. A systems approach that reveals its relationship to other parts of the system is examined in the light of producing more sustainable practice.The move to a more sustainable society requires greater sophistication to manage waste. A traditional reductionist approach is unsustainable as it lacks flexibility and long term thinking.A sustainable waste management system incorporates feedback loops, is focused on processes, embodies adaptability and diverts wastes from disposal.Transitioning to a sustainable waste management system requires identification and application of leverage points which effect change.