No one has ever sat down to imagine that they are consuming water that is contaminated by raw and and partially treated municipal and industrial effluents. It is nauseating to even picture it.
But unknown to many residents of Kisumu, Homa Bay and Bomet Counties, and other people living around Lake Victoria, this has been going on for several years.
In Kisumu, the Kisat Sewerage and Treatment plant was operational, but lacked capacity to handle waste products that were coming from the town due to the growing population. It therefore was not able to effectively handle the waste.
The plant located in the North West of Kisumu next to River Kisat that drains into Lake Victoria, was first constructed in the year 1958 with capacity of 2,270 cubic metres a day.
It was later rehabilitated in the year 1985/1986 and this increased its capacity to 6800 cubic metres per day.
The plant receives sewage from both domestic and commercial places located within Kisumu Central Business District and industrial area.
Apart from that, it also receives heavy amounts of oils from garages, and factories on the lower shores.
In Homa Bay, the first sewerage system was constructed in 1979 and rehabilitated in 2002.
It however, degenerated due to frequent mechanical break downs, and raw sewage started seeping directly into the lake. Most of the residents of Shauri yako, Sofia and Got Rabuor indicated they not connected to the main sewer network of the town.
In Bomet, there had never been an existing sewerage system serving its residents. The population of Bomet used to rely on pit latrines and septic tanks for disposal of sewage.
When they got filled, the waste would be discharged into ponds whereby the water component was being lost through evaporation.
Others decided to exhaust the latrines and septic tanks manually, by drawing the waste and disposing it in drains that flow to River Nyangores.
The lake water was highly polluted with raw sewerage from the old sewer line and this is said to have caused a number of deaths through waterborne diseases.
This also led to the presence of water hyacinth that is an eyesore to the lake. Due to the waste disposal problems encountered in the three counties, the Lake Victoria Environment Management Programme II (Lvemp II), through funding from World Bank decided to rehabilitate the Kisat and Homa Bay Sewerage plants, and embarked on construction of the Bomet Sewer system.
The rehabilitation and construction began in 2014, after Lvemp II set aside over Sh500 million in late 2013 for development and rehabilitation of sewer systems in the three counties in a bid to reduce untreated effluent discharge in the lake.
Sewage treatment plants are constructed to transform raw sewage into an easier manageable waste and to retrieve and re use the treated sewage water, if possible.
Lvemp II’s Environmental Specialist Solomon Kihiu says they installed the primary sedimentation tank at Kisat.
“The Primary Sedimentation tank receives effluent from the environment which was fitted with an electro-chemical gadget on top,” he says.
The primary sedimentation tank helps in water treatment using gravity to remove suspended solids from water
They also got a secondary sedimentation tank that allows the microorganisms and other solids to settle after secondary or biological treatment, and sludge digestors that break down biodegradable material through the use of microorganisms.
“Filters were also purchased to remove impurities from the waste water,” he says.
Due to the intense purification process, water being released into lake Victoria was found to be of required standards according to National Environmental Management Authority (Nema).
“The standard Biological Oxygen Demand (BOD) is 27-30 milligrams per litre (mg/litre). Before rehabilitation of Kisat, we used to receive approximately 50 mg/litre. The recommended level is between 30-35mg/litre,” he says.
The Chemical Oxygen Demand was at 120mg/litre before and is currently between 50-60mg/litre, yet the recommended level is 50mg/litre. Transparency level however remains the same.
“The settle-able solids quantity and conductivity are also in accordance with required water quality standards, apart from phosphates whose recommendation is 8.6mg/litre yet we are currently at 7.6mg/litre,” Kihiu says.
As for nitrates, Kihiu urges the county government to avail a parcel of land where an artificial wetland will be put to get rid of the nitrates.
He adds:” There is no need to worry about the high phosphates being released to the lake because the water is still safe. But we want to reduce the quantity so that even the little water hyacinth in the lake is deprived off nutrients completely. We still need a tertiary tank (artificial wetland)”.
Lvemp II Water Specialist Isaiah Mawinda says reduction of water hyacinth to almost negligible levels can be attributed to the waste water treatment currently taking place in Kisumu.
“Before this facility was rehabilitated, one could not endure the odour emanating from this facility as far as about 200 metres. That is now history because one can comfortably have their meal here. That is an indication that this place has greatly improved,” he says.
He says the Bomet County facility was built from scratch at a cost of Sh135 million with a two kilometre trunk line to connect the sewer facility to homes.
Bomet County Director of Environment Moses Murindat says the treatment plant is going to reduce pollution of water that ultimately drains into Lake Victoria.
“We believe Bomet water and sewer system is compliant to Nema regulations,” Murindat says.
Bomet’s Environment Executive officer, Alex Kirui says they are already in the process of demolishing pit latrines that were being used in the county before construction of the sewer system.
“The latrines are dangerous because of the soil type we have. They also act as breeding grounds for mosquitoes,” he says.
He says the number of universities in the county have also increased following construction of the treatment plant.
“One of the universities is situated next to the plant and they say there is no odour at all. This is impressive,” Kirui says.
In Homa Bay town, the facility that had been abandoned before due to a huge electricity bill was rehabilitated.
Homa Bay Water and Sewerage Company (Homawasco)’s Technical Manager Dickson Odira says a settlement tank, an anaerobic pond inlet, utility building and a perimeter wall have been constructed.
“Before rehabilitation of this facility, only 540 connections had been done in this county. We now have about 1,053 connections comprising 25 major clients like schools and hotels, 100 commercial buildings and 928 households in an area with a population of about 27,140,” he says.
The rehabilitation work commenced in 2014 and was completed a year later.
“The whole system had collapsed. This is a totally new system that is helping us release clean water into Lake Victoria,” he says.
He says the former pond was aerobic and could not function without oxygen, but the current one is anaerobic.