Crime scene detectives from Rwanda Investigations Bureau and officers from the Police were seen on Thursday afternoon at Kimisagra water Treatment plant inquiring about the death of a worker.
Preferring anonymity a source at the plant told Taarifa that a casual worker died while cleaning up inside a sedimentation tank that is almost 12 metres deep.
“At about 2:30PM other workers standing on top of the sedimentation tank heard their colleague below shouting asking the technicians to immediately cut off power supply to the machine,” the source said.
The victim has been identified as Nsengiyumva Emmanuel, “we notified the police and local authorities about the incidence and they promptly arrived at the station. His body has been taken for postmortem.”
Investigations are already ongoing to ascertain what could have led to sudden death of this casual labourer at the plant.
Following the recent heavy rains, water entering the treatment plant has been arriving with a lot of contamination. This has been requiring regular cleanup of the sedimentation tank in which much clay and silt find their way.
At this particular Kimisagara water treatment station, water flowing from Yanze riverfeeds into the processing plant.
Insight into Water Treatment Process
Water from streams or rivers such as Nyabarongo is diverted into a water treatment plant to undergo various steps until it leaves the site as safe and clean drinking water and is piped for distribution to the public. The steps are summarized as; clarification, filtration and refining.
The first step is removing the dissolved solids suspended in the water. Chemicals called coagulants are added to the water to destabilize suspended solids, dissolve organic matter and other substances.
Previously Rwanda used Aluminum Sulfate chemical at this stage. This chemical has a charge opposite from the suspended solids, like clays or silts. It therefore neutralizes the charge and allows for the particles to stick together.
Rwanda has however, suspended the use of Aluminium Sulftate because of its negative effects on lives.
The government has adopted a new water purification chemical- Sudfloc Cationic Polymer Blend which is a liquid type, high cationic charge density, working as coagulant for water purification and clarification for river water, raining water.
Aluminum accumulation in the brain is proposed to be associated with neurodegenerative diseases, including; Alzheimer’s dementia, Parkinson’s disease, amyotrophic lateral sclerosis, and dialysis encephalopathy
The mixture is slowly mixed in a flocculation basin in order to continue to form what are called floc particles. These floc particles then settle out of the mixture in a sedimentation basin, and cleaner water flows overtop a levee.
Following sedimentation, the next step is typically filtration through a sand filter. After passing through the sand filter, the water should have clarity (turbidity) but bacteria are still present.
The final step in the process is disinfection.
Chemicals such as chloramines or chlorine-based compounds are added with the aim of killing microorganisms, but they also react with any organic material left in the water.