Sewage is liquid waste containing a mixture of human feaces and wastewater from non-industrial human activities such as bathing, washing, and cleaning.
In many poor areas of the world, untreated sewage is dumped into local waterways; in the absence of practical alternatives. It poses a major risk to human health since it contains waterborne pathogens that can cause serious human illness. It also destroys aquatic ecosystems, threatening human livelihoods.
Improved sanitation facilities are those that eliminate human contact with feacal material and include flush or pit toilets and latrines and composting toilets.
Even where water-based toilets are available, the wastes are far too often just discharged into drains and streams, in the absence of (expensive) collection and treatment systems. As a result, surface waters in many urban areas are highly contaminated with human waste.
In areas with pit latrines, seepage into local groundwater is often a major problem since many communities rely on shallow wells for drinking water. Lack of access to improved sanitation disproportionately affects poor communities in urban and rural areas where resources for investments in collection and treatment infrastructure are scarce. However, the challenge of maintaining existing systems to protect humans from waterborne disease outbreaks affects even the world’s richest communities.
Water Services Regulatory Board in 2018 recorded an average of 16 per cent sewerage reticulation nationally, which is far below the policy goal under Vision 2030 to increase sanitation coverage in Kenyan urban areas to 100 per cent. This was to be achieved by increasing coverage of sewerage system to 80 per cent and installing improved on-site treatment facilities for populations not covered by sewerage systems.
Some 48 per cent of households in Nairobi are connected to the main sewer, while the rest lack adequate sewerage connection system.
The water coverage in Kisumu is below 50 per cent and sewerage eight per cent. Therefore, access to safe and affordable water and dignified sanitation are the main challenges facing the residents of Kisumu.
The majority of residents get water from numerous self-supply wells because piped water is either intermittent or unavailable. Due to low sewerage coverage, most low-income residents use self-constructed pit latrines for sanitation.
In Mombasa, the sewerage system coverage is only 10 per cent and it is the lowest of all towns in Kenya. Improper use of septic tanks and immense pressure to handle large volumes of wastewater leads to overflows.
In Eldoret, sewerage connectivity stands at 30 per cent, while only 27 per cent of Nakuru residents are connected to the sewerage system. This raises a concern for the need for a better way to dispose of the large quantities of human waste generated each day.
The threat of water contamination in Nakuru is real as human waste is often dumped in storm drains and rivers, or is buried in low-income areas. In turn, human waster is finding its way into nearby Lake Nakuru, polluting the ecosystem.
Marine pollution is an area of global concern owing to its adverse impacts on ecosystems and human health. The impacts are expected to rapidly expand to remote pristine coastal habitats, including some highly sensitive ecosystems such as Kenya.
Sewage pollution is often manifested by elevated concentrations of inorganic effluents and causes facial swellings and rashes. Society and managers require tools based on sound scientific knowledge to properly monitor, manage and protect such sensitive marine areas.
Contamination of the coastal water may result in changes in nutrient levels, abundance, biomass and diversity of organisms, bioaccumulation of organic and inorganic compounds and alteration of trophic interaction among species.
This sewage can intentionally be discharged to waterways through pipes or open defecation, or unintentionally during rainfall events. When humans use these waterways for drinking, bathing or washing, they are exposed to the associated pathogens, many of which can live for extended periods of time in aquatic environments.
Humans then become ill by ingesting contaminated water, by getting it on skin, eyes or ears, or even from preparing foods with contaminated water. Sometimes humans can even become ill from inhaling contaminated water droplets.
Life-threatening human pathogens carried by sewage include cholera, typhoid and dysentery. Other diseases include schistosomiasis, hepatitis A, intestinal nematode infections, and numerous others.
WHO estimates that 1.5 million preventable deaths per year result from unsafe water, inadequate sanitation or hygiene. These deaths are mostly among young children. Another 860,000 children less than five years old are estimated to die annually as a direct or indirect result of the underweight or malnutrition associated with repeated diarrhoea or intestinal nematode infections.
Sewage contamination is a global threat that occurs in most areas where humans live and nature is often nearby; it is possible that sewage also globally threatens natural habitats and biodiversity.
Secretary, National Environmental Complaints Committee [email protected]
