6 December 2009
SCIENTISTS have revealed that the quality of water supplied to Kampala is deteriorating. A team of professors and scientists from Makerere University and the University of Bergen in Norway, reveals in a report after a four year study, that consumption of Lake Victoria water is disastrous. The authors say the National Water and Sewerage Corporation, the body responsible for water distribution in the city, needs to do more.
In the report: Sharing water, Problems, conflicts and possible solutions-the case of Kampala, the scientists suggest that developments in science and technology will solve future challenges concerning the environment. “A lot of heavy metals remitted by the industries end up in Lake Victoria. The swamps, wetland soil and plants accumulate the metals,” said Prof. Petter Larsson from University of Bern. The study, released at Makerere University last week, shows that Nakivubo swamp (channel) has high concentrations of zinc, lead and nickel. “The soil and plants had concentration above accepted international standards,” said Dr. Anne Miyingo, a senior lecturer at the department of zoology in Makerere University. She said food and vegetables should have a metal concentration below 1mg/kg.
Prof. Edward Kirumira dean faculty of Social Science Makerere University said although the Government wants factories to strengthen national economy, it must not ignore the pollution caused. “In Kampala, the water environment is socially determined. Inhabitants of Nakasero and Kololo have indoor water and are also connected to sewer systems that lead to the treatment plant in Bugolobi,” said Kirumira. “However, the sewer has not been maintained. In many places, manhole covers have been stolen and the sewer filled with rubbish.” The sewarage works were designed to treat 32,000 cubic metres per day but are receiving less due to blockages in the system.
People who live on hills are better off because they have septic tank systems where the liquids are disposed in the ground, while the solid parts are collected and taken to the sewage plant. The study points out that most people without toilets use pit latrines or plastic bags. “Most of the poor in Kampala live in wetlands, where spring water is contaminated, malaria cases are high and the risk of flooding is great,” said Dr. Ssengendo. He said industries in Kampala, close to wetlands, discharge effluents into water sources from which some residents collect domestic water. “Of the sewerage produced, only 27% is treated in Bugolobi. About 10% of the population produces sewerage from toilets, what happens to the 90%? Pit latrines have to be emptied by flushing during floods,” Ssengendo said.
Kampala City Council collects 25% of the solid waste generated every month while households in slums make arrangements to dispose waste at mini-open-dump sites near their backyards. “As the dumped waste decomposes, the runoff seeps into water sources and contaminates them during the rainy season,” read the report. Wetlands are effective natural filters that purify polluted water. However, Nakivubo swamp has reduced its cleaning capacity due to increased agriculture and buildings, which allows waste to seep into Lake Victoria.
The scientists point out an inherent conflict between water meant for human use and the waste water produced. “Domestic water should not contain any living organisms, particles or polluting chemicals,” says Kirumira. Bacteria, algae cells, aquatic animals, dead organic particles and ions of heavy metals are not acceptable in water used for drinking, food production, cleaning and swimming. The study also states that: “In contrast to drinking water, waste water contains compounds and particles we want to get rid of. Some might be poisonous, but most of them are breakdown products from organic compounds like faeces and cleaning agents.”
From the water works point of view, using a water body that is a recipient for waste water creates problems. Extra effort has to be used in the cleaning process. If the raw water for the waterworks is mixed with waste water, special treatment is necessary,” said Kirumira. Chlorine added to drinking water removes most harmful micro-organisms but some parasites are resistant to the treatment. Particles like mercury may accumulate in living organisms through the food chain and end up in high concentrations in fish due to the bio-accumulation,” reads the report.
Highlights
- 27% of sewage produced is treated in Bugolobi.
- 10% of the population produce sewage from toilets.
- KCC collects 25% of the solid waste produced every month.
