Arriving or landing in the lakeside city of Kisumu County, one would be cheated and get fascinated of a green bear stadium or plantation of some crops. But alas! This is water hyacinth covering thousands of acres of water surface totally blocking appearance of Lake Victoria.

The hyacinth is large promoted by effluent discharged from strategically and carefully hidden points deep inside certain thickets. ScienceAfrica Investigative Journalist can reveal this after thorough and intensive investigations.

After spending time with employees of various industries for close to two weeks camouflaging as a job seeker, many secrets began revealing itself. For this secret information to come out, my fixer/point-man the tour guide and myself set several meetings ahead to plan on how to work together without being noticed of our mission for this investigative piece.

Several attempts to locate effluent discharge outlets from various industries failed but we never lost hope. Persistence gave us some green-light after five days of search of course with a hint from a villager. Walking approximately 300 metres away from the busy Kisumu-Busia highway, we went to a deserted field that seemed owners have some land issues in a Court of Law.

However, it took us more than an hour walking in circles along a small stream that meanders into Kisat River to finally find the effluent discharge outlet. It really takes courage, perseverance and team work backed up by trust to succeed.

This is because the seepage point is strategically put in a nearly impenetrable canopy of tall overgrown shrubs, interwoven in tree trunks that cast a shroud of darkness even at midday on a bright sunny day. Sharp objects, among them stones, broken glasses, bones of carcasses, and left soggy to discourage anyone from moving towards that point.

Again, as one gets closer, you are met with strong, unmistakable, septic stench that leads you directly to it. We had to squeeze ourselves in until we finally burst through the trees and past the darkness. There it was, but we were left baffled and scared, wondering what could happen to us in case of any attack.

When you finally find it, you will know it is poison and the toxic environmental stench say it all to stay for more than 5 minutes. It is contrary to the flora growing around it enjoying including the fertile land. To confirm this, around it are tiny farms growing all manner of crops from vegetables, yams, to napier grass, giving it a beautiful cover.

These tiny plots are separated by deep-water trenches, which make crossing from one small part to the other dangerous. The alternative way to access it, is swimming across the angry, filthy river next to the plant. If you do not drown, then you will meet a slippery climb that is impossible to beat without bruising yourself. But in case you do, certainly your whole-body would itch.

Some companies hire tankers/bowsers fitted with exhausters to dump used oils, raw effluent, expired/rejected chemicals in the nearby rivers which ends up in the lake. This specifically happens late in the night and vehicle registration number -plate sealed using dark thick mud to hide identity.

Toxic Seepage

The effluent spewed into the river paints elegant swirls of brown and white, like sugar stirring in a cup of latte, only that this is a lethal concoction. Its colour, smell and the foaming as it is ferried down into Lake Victoria tell a shocking story of betrayal, of a protector-turned-prey.

By the time of going on press, Kisumu Water and Sewerage Company (Kiwasco), which runs the Kisat treatment plant, was still in denial that it was polluting the lake.

The taxpayer funds Kiwasco to do three major functions. The water company should connect as many residents as possible to clean and safe drinking water. The second and perhaps the most important function is to collect and treat all poisons pumped into its sewer lines from industries upstream. It is also expected to clean the raw sewage flushed down its system before releasing it into rivers.

However, ScienceAfrica Investigation Journalist confirmed the worst fears for residents of the lake region, especially how badly the water company is failing. Kiwasco lacks capacity to clean the toxic waste it receives  on a daily basis. Overwhelmed, it is pumping poison into Lake Victoria, hoping that the lake can dilute the poison on its behalf.

In one of the biggest scandals to rock the water industry, Kiwasco is pumping at least seven dangerous chemicals into the lake. Chemicals that can cause all manner of diseases from cancer to the damage of respiratory systems. This may partly explain why respiratory diseases have overtaken malaria as the deadliest diseases in the Lake Region. There are also far too many people battling diseases like cancer of late.

Ironically, the same company is harvesting water from the same lake, not too far away from where it is releasing its waste. This is the water it cleans and distributes to hundreds of thousands of residents in the region, thus a double tragedy.

Our independent tests conducted in partnership with the University of Nairobi, Toxicology Laboratory revealed that the effluent has extremely high levels of Cadmium and Chromium, at concentrations far beyond the acceptable standards.

Cadmium is a dangerous metal. Together with its compounds, it is highly toxic. Exposure to it is known to cause cancer. Cadmium mainly targets the body’s cardiovascular, renal, gastrointestinal, neurological, reproductive and respiratory systems. Exposure to lower levels of the metal for a prolonged period can also damage the kidneys, lungs and bones.

Chromium is not any better. Exposure to high concentrations of it causes lung and respiratory tract cancers as well as kidney diseases. Over-exposure to Chromium may also cause gastrointestinal   symptoms such as diarrhoea and vomiting, often with blood.

The Kiwasco effluent also tested positive for lead, zinc, iron, manganese and fluoride, all heavy metals, but these were in safer levels.

Impact of metallic materials

Excessive lead causes decreased mental, nervous system and physical development in children. In adults, it causes high blood pressure, kidney damage and reduced fertility.

But perhaps the most unforgivable act is Kiwasco’s passing of raw sewage it is supposed to treat into the lake. Our results confirmed that very little treatment of the effluent had occurred.

The effluent sample we collected tested positive for two types of bacteria that are mainly found in untreated human waste and they were appearing in their total concentration. We found E. coli and total coliforms in excess of 1,800 per 100mls sample.

Our scale only measured up to 1,800 and so the concentration could have been much worse.

To put it into perspective, these counts are 60 times above what is allowable by the National Environment Management Authority (Nema). This is the same level found in raw sewage. Clean water should have nil E. coli while total coliforms should not be more than 30 in every 100mls of water.

Escherichia is a type of bacterium that lives in the intestines. It is, therefore, transmitted through human waste. It is also found in the gut of some animals.

Coliforms are not one kind of bacterium, but many, and they can make you sick if ingested from drinking water. Total coliforms include bacteria found in soil, water and in human or animal waste. Coliform bacteria have no taste, smell, or colour. They can only be detected through a laboratory test.

Most of these bacteria are harmless and even help keep your digestive tract healthy. However, some strains can cause diarrhoea if you eat contaminated food or drink fouled water.


Just recently, residents of Kisumu started complaining of a septic smell from Lake Victoria when they noticed that the lake was stinking like raw sewage. So none of Kisumu residents paid their water bills for one month.

However, in bid to calm their nerves and to lie to their faces once more, Kiwasco said its attention had been drawn to public complaints regarding the pungent smell emanating from Lake Victoria and mostly around KICOMI situated along Kisumu-Busia Road.

“We would like to inform members of the public that the smell along the old airport roads and the Kisumu-Busia highway is as a result of natural occurrence of blue-green algae bloom in fresh water ecosystems which causes the septic smell,” Thomas Odongo, Kiwasco Managing Director said.

Odongo blamed the septic smell on these ‘blooms’ that he said can occur in response to favourable conditions brought about mainly by deposits of water hyacinth or water weeds on the lake basin. He maintained fortunate include; still or slow-flowing water, abundant sunlight, hot temperature and sufficient levels of nutrients, conditions currently prevailing on the shores of Lake Victoria.

“We, therefore, assure the public and residents of Kisumu that our Kisat sewer treatment plant is operating normally and our effluent treatment and discharge is according to the required effluent environmental standards,” Odongo said.

Kiwasco maintained that as a beneficiary of Lake Victoria, it has taken upon itself to manage the situation by creating an environment where there is free flow of water at abstraction points.

We reached out to Nema concerning our investigative piece and findings and they promised to follow up and carry out their independent investigation as well.

This Environmental Investigative Journalism was made possible with the support of WITS Journalism and the African Investigative Journalism Conference(AIJC)Project.