ASSESSMENT OF THE IMPACT OF SEWAGE DISPOSAL PRACTICES ON WATER QUALITY IN URBAN AREAS OF CAMEROON: A CASE STUDY OF DOUALA

CHAPTER ONE

INTRODUCTION

Background of the Study

In developed and developing nations, dues to human activities, residences, institutions, hospitals, and commercial and industrial facilities generate sewage. Sewage, known as raw influent, consists of liquid waste from toilets, baths, showers, kitchens, sinks, and other sources, which is then discharged through sewers. As highlighted by Faadun (2022), in the industrialized world, there is an increasing trend of separating and disposing of domestic waste into two categories: grey-water and blackwater . Grey-water, which is relatively clean, is allowed to be used for purposes such as watering plants or recycling it for flushing toilets.  On the other hand, sewage refers to the waterborne waste materials, which might be in a dissolved or suspended state, that are discharged from a community. It is sometimes referred to as the discharge of waste water or the utilised water supply of the community. It is a type of water that is more than 99.9% pure, and is defined by its volume or flow rate, physical state, chemical components, and the presence of bacteria. 

According to Desmond (2023) sewage in numerous regions encompasses liquid waste generated by both industry and commerce. Wastewater can be categorised into many types based on its source, including sanitary, commercial, industrial, or surface runoff.. Domestic or sanitary sewage refers to the water that is discharged from homes and institutions, containing bodily waste, used washing water, food preparation waste, laundry waste, and other waste generated from everyday activities. Commercial wastes, which refer to liquid-carried wastes from stores and service establishments that serve the local community, are classified as sanitary or domestic sewage if they have similar characteristics to residential flows (Moore, 2019). On the other hand, industrial wastes are classified as the byproducts of an industrial process or the production or manufacture of items (Ngobiri et al, 2019).. Their fluid dynamics and capabilities are typically more diverse, powerful, and focused compared to that of sanitary sewage. Surface runoff, sometimes referred to as storm flow or overland flow, is the part of precipitation that quickly flows over the ground surface and into a specific channel. Precipitation assimilates gases and particles from the atmosphere, dissolves and extracts substances from vegetation and soil, suspends stuff from the land, cleanses spills and debris from urban streets and highways, and transports all these contaminants as waste in its movement towards a collecting point. The wastewater originating from these many sources may contain dangerous microorganisms capable of transmitting diseases to humans and other animals. Additionally, it may contain organic substances that can generate unpleasant odours and cause disturbances. Furthermore, the wastewater may contain nutrients that can contribute to the excessive growth of aquatic plants and algae in receiving water bodies, a phenomenon known as eutrophication. 

Consequently, the presence of wastewater can have detrimental effects on the ecological balance, leading to eco-toxicological consequences hence the proper gathering and secure, hassle-free elimination of the liquid byproducts of a population are legally acknowledged as an essential requirement in a developed, industrial civilisation.  According to Asunadim (2020) sewage disposal is the method by which wastewater from residential and commercial sources, often consisting of a liquid containing small solid particles, is conveyed through enormous pipes known as sewers to create a safe and environmentally friendly waste product (Ask, 2019). The wastewater is either routed to a specified location for recycling or disposed of in a remote area to prevent the spread of infections. The proper management of sewage waste safeguards public health and mitigates the risk of disease transmission, while also preventing water pollution caused by sewage toxins. The majority of cities in affluent countries possess efficient sewage disposal systems, which are complemented by technological progress. There have been advancements that enable the use of more ecologically sustainable and health-conscious methods for disposing of and treating sewage. 

Specifically, domestic wastewater discharges are widely recognised as a major danger to coastal habitats globally (GPA, 2021). The environmental impacts linked to the outflow of domestic wastewater are primarily localised, but may have transboundary consequences in certain regions. Coastal waterways are experiencing several pressures that impact both the ecology and human health. These pressures arise from the discharge and disposal of sewage waste-water, which can introduce excessive levels of nutrients, dangerous chemicals, and disease-causing bacteria. The detrimental effects of sewage contamination in coastal areas on public health, environment, socio-economic factors, food quality and security, and aesthetics have been well documented. (Luker and Brown, 2019, Tyrrel, 2019, Danulat et al 2022, WHO, 2022).

Consequently, coastal water pollution typically disrupts a range of water activities. Cultivated bivalves are typically raised in densely populated regions that are highly susceptible to significant pollution caused by human activities. The primary source of bacterial pollution in the water is the discharge of sewage contaminated with human and animal infections, which are typically transmitted through human faeces. Each pathogen found in saltwater has the potential to be captured and concentrated in the tissues of bivalves, making them a potential health risk. Many countries have established legislation, directives, and water quality standards to address issues related to sewage and its impact on coastal activities such as shellfish harvesting, recreation, drinking water, and aquaculture.  Therefore these water pollution issues in coastal areas in Cameroon that necessitates effective management strategies to mitigate its affects, as urban populations heavily rely on coastal surface waterways, which are commonly utilised for sewage disposal. Therefore, a survey will be conducted in order to assess the impact of sewage disposal practices on water quality in urban areas of Cameroon.

Statement of the Problem

In recent times, development in the 20th Century has changed rural communities to urban centres that today face a lot of environmental challenges. Such environmental issues are being addressed at global, regional and local levels. The most current environmental issue is disposal of waste from domestic, commercial and industrial sources. The production of waste remains a major source of concern today as it has been since prehistoric times (Chandler et al., 2019). A substantial increase in the volume of waste generated started in the sixteenth century when people began to move from rural areas to cities due to the industrial revolution (Wilson, 2019). This migration of people to cities led to population explosion that in turn led to a surge in the volume and variety in the composition of waste they generated. It was then that materials such as metals and glass began to appear in large quantities in municipal waste streams (Williams et al., 2021). 

Bizarrely, in most Developing Countries, municipal solid waste (MSW) disposal has been a chronic problem, particularly in areas with high population densities and high refuse production. Scarcity of land for landfills often gives rise to indiscriminate dumping of refuse in surface water bodies and improper landfill systems. Open dumps have been highlighted by many workers to pose serious threats to groundwater and surface water resources (Slomczynka, 2018). The degree of threat is strongly influenced by the composition of the waste in the landfill, the volume of leachates generated as well as the location of the landfill from water bodies such as groundwater and surface water (Slomczynka, 2018). This in turn has led to pollution of surface and groundwater causing over 20% of the world population not to access safe drinking water

Contextually, in Douala, Cameroon, an area on the Wouri River surrounded by water bodies and the hub for major commercial and industrial activities. These water bodies have become sites for indiscriminate waste disposal for the commercial activities as well as effluents from the industries within. Hence, it is in the light of these that the study seeks to assess the impact of sewage disposal practices on water quality in urban areas of Cameroon.

 1.3  Objectives of the Study

The main purpose of this study is to assess the impact of sewage disposal practices on water quality in urban areas of Cameroon.  Specifically, the study will;

Evaluate the sewage disposal practices in urban areas of Cameroon.

Determine the impact of sewage disposal practices on water quality in urban water bodies.

Determine the pollutants associated with sewage disposal and their levels in water sources.

Determine the strategies for improving sewage disposal practices to protect water quality.

1.4  Research Questions

The following questions have been prepared for the study:

What are the sewage disposal practices in urban areas of Cameroon?

What are the primary contaminants associated with sewage disposal?

Are there significant differences in water quality between areas with different sewage disposal practices?

What measures can be implemented to reduce the negative impact of sewage disposal on water quality?

1.5 Research Hypotheses

H0: Sewage disposal practices in urban areas of Cameroon do not significantly affect the quality of water sources.

Ha: Sewage disposal practices in urban areas of Cameroon significantly affect the quality of water sources.

1.6 Significance of the Study

This study will have major for urban planners, environmental regulators, and public health experts in Douala. The report will include practical suggestions for optimising sewage disposal methods and improving water quality management systems. This will help decrease the likelihood of waterborne infections and environmental deterioration. Furthermore, the results will contribute to the formulation of policies and initiatives aimed at guaranteeing the provision of safer and more environmentally friendly water for urban residents.Moreover, subsequent researchers will use it as a literature review. This means that other students who may decide to conduct studies in this area will have the opportunity to use this study as available literature that can be subjected to critical review.

1.7 Scope of the study   

The scope of this study is boarded on impact of sewage disposal practices on water quality in urban areas of Cameroon. Geographically, the study will be delimited to residents of Cameroon.

1.8 Limitation of the study

In the course of carrying out this study, the researcher experienced some constraints, which included time constraints, financial constraints, language barriers, and the attitude of the respondents. In addition, there was the element of researcher bias. Here, the researcher possessed some biases that may have been reflected in the way the data was collected, the type of people interviewed or sampled, and how the data gathered was interpreted thereafter. The potential for all this to influence the findings and conclusions could not be downplayed. More so, the findings of this study are limited to the sample population in the study area, hence they may not be suitable for use in comparison to other schools, local governments, states, and other countries in the world.

 1.9 Definition of Terms

Waste: Any material, substance, or byproduct that is discarded, unwanted, or considered to have no further use.

Sewage: Wastewater that is generated from domestic, industrial, and commercial activities, which typically contains human waste (feces and urine), household waste (such as detergents and food residues), and water used for washing, bathing, and cleaning.

Sewage disposal: The process of collecting, treating, and safely discharging or recycling sewage to prevent pollution and protect public health.

Water Quality: The measure of the physical, chemical, and biological characteristics of water, which determines its suitability for specific uses such as drinking, recreation, agriculture, or industrial processes.

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