Kenya’s aquatic environments, including lakes, rivers, wetlands, and coastal zones, are increasingly threatened by improper waste disposal. Professionals working near or on these water bodies, whether in hospitals, hotels, farms, county offices, or transport sectors, must understand the types of waste generated and the correct procedures for disposal. Effective waste management not only protects aquatic life and public health but also ensures compliance with environmental laws such as the Environmental Management and Coordination Act (EMCA). This chapter explores the main categories of waste found in aquatic environments and outlines best practices for their safe handling and disposal, both onshore and onboard vessels.

1.1 Types of Waste in Aquatic Environments

Aquatic environments in Kenya are exposed to diverse forms of waste originating from human activity, industrial processes, and natural events. Understanding the nature and sources of these wastes is essential for selecting appropriate disposal methods and minimising environmental impact. Organizations such as county referral hospitals, schools, farms, and hotels contribute different waste types, each requiring specific handling.

1.1.1 Domestic and Municipal Waste

Domestic and municipal waste includes materials discarded from households, institutions, and urban centers. In towns bordering Lake Victoria or along the Tana River, this waste often finds its way into water bodies due to inadequate collection or illegal dumping.

Key Components of Domestic and Municipal Waste

• Biodegradable waste: Food scraps, kitchen refuse, and garden trimmings decompose naturally but can deplete oxygen levels in water when dumped, harming aquatic life.
• Non-biodegradable waste: Plastics, glass bottles, cans, and metal packaging persist in the environment, increasing the risk of water pollution and harming fish and birds.
• Paper and cardboard: While biodegradable, large quantities can still disrupt aquatic ecosystems by altering water flow and blocking drainage channels.
• Textiles and clothing: Old garments and fabrics can entangle aquatic animals and contribute to microplastic pollution as they degrade.
• Household hazardous waste: Batteries, cleaning chemicals, and expired medicines pose serious risks if leached into water systems.

In Kisumu, for example, poorly managed domestic waste from markets and residential areas is a leading cause of shoreline pollution, affecting both local communities and tourism.

1.1.2 Industrial, Construction, and Demolition Waste

Industrial activities and construction projects near aquatic environments generate significant waste streams. These include both hazardous and non-hazardous materials.

Types of Industrial and Construction Waste

• Industrial by-products: Solvents, paints, and chemical residues can be toxic to aquatic organisms and contaminate drinking water sources.
• Construction debris: Concrete, bricks, tiles, and iron sheets may physically alter watercourses and create breeding grounds for disease vectors.
• Demolition waste: Old pipes, insulation materials, and fixtures often contain heavy metals or asbestos, which are dangerous if released into water bodies.
• Timber and wood offcuts: These can float and obstruct navigation or contribute to organic pollution as they decay.
• Waste tires: Discarded tires are sometimes dumped near rivers, where they trap water and create mosquito breeding sites.

A hotel undergoing renovation in Mombasa must ensure that construction waste is properly collected and disposed of at licensed facilities to prevent material from entering the Indian Ocean.

1.1.3 Bio-Medical, E-Waste, and Sewage Sludge

Specialized waste streams pose unique threats when mishandled in aquatic settings. Facilities such as hospitals, laboratories, and ICT centers must be particularly vigilant.

Characteristics of Bio-Medical, E-Waste, and Sewage Sludge

• Bio-medical waste: Includes used syringes, bandages, pharmaceuticals, and laboratory waste. If these items reach water bodies, they can spread infections and introduce toxic substances.
• E-waste: Obsolete computers, mobile phones, and electrical appliances release heavy metals like mercury and cadmium, contaminating both water and sediments.
• Sewage sludge: A by-product of wastewater treatment, sludge may contain pathogens and heavy metals, especially if industrial effluents are mixed with domestic sewage.

A county referral hospital in Eldoret, for example, must segregate infectious waste and ensure it is incinerated or treated before disposal, preventing runoff into nearby streams during heavy rains.

1.1.4 Agricultural and Green Waste

Farming activities near aquatic environments contribute both organic and chemical wastes. These can have far-reaching effects on water quality and aquatic biodiversity.

Sources and Impacts of Agricultural and Green Waste

• Animal manure: Runoff from livestock pens introduces nutrients and pathogens into rivers, leading to eutrophication and disease outbreaks.
• Pesticide and fertilizer residues: Excess chemicals washed from farms can cause algal blooms and contaminate fish stocks.
• Crop residues: Stalks, leaves, and husks may block waterways and decompose, reducing water quality.
• Greenhouse plastics and seedling trays: Discarded materials from horticultural operations add to non-biodegradable waste loads.
• Aquaculture waste: Uneaten feed and fish excrement accumulate in fish ponds and can overflow into natural water bodies.

A cooperative of rice farmers in Mwea must adopt best practices for managing agricultural waste to prevent pesticide runoff into the Thiba River.

Chapter Summary

This chapter provided a comprehensive overview of waste management in aquatic environments, beginning with the identification of various types of waste commonly found in these settings, such as plastics, oils, chemicals, and organic matter. It then explored the procedures for disposing of waste onboard vessels, emphasizing the importance of proper segregation, storage, and handling to minimize environmental impact. The discussion also covered crucial measures to prevent operational pollution, including regular maintenance, use of pollution control equipment, and adherence to established protocols. The chapter further detailed the official waste disposal procedures designed to protect the marine environment, highlighting the need for compliance with regulations and best practices. Throughout, the importance of individual and collective responsibility in safeguarding aquatic ecosystems was reinforced. By understanding these procedures and measures, professionals can contribute to healthier water bodies and sustainable resource use. The chapter emphasized that effective waste management in aquatic environments is essential for the long-term well-being of both human communities and natural habitats.