Environmental Talk: Green Water in our Pipes - Chickens coming home to roost
Product of Kampala: Sewage flowing in open channels in Kampala.
(Image sourced from Eng.Herbert Mpagi Kalibbala)

Environmental Talk: Green Water in our Pipes - Chickens coming home to roost


Residents of Kampala wake up to green water in their taps.

By Ivan Kibuka-Kiguli
more from author >>
First published: September 10, 2007


In late July 2007, residents of Kampala connected to the National Water and Sewerage Corporation (NW&SC) potable water network were alarmed by what was coming out of their taps. The water that has always been colourless turned light green. This prompted some health officials to run some tests on water from taps around Kampala after which they dropped a bombshell; there are disease-causing organisms in the water at levels that should make us ill!


For the public, naturally the first culprit to be held accountable should the supplier, NW&SC. Or is it? While NW&SC may have its failures and weaknesses, let us look at the source from which it draws the raw water that it supplies to Kampala and the surrounding areas. Lake Victoria is the ultimate destination of most sewage generated in Kampala. It receives both domestic and industrial wastewater. According to the New Vision, statistically, only 8% of Kampala's buildings are connected to NW&SC's sewer lines. Much of Kampala's wastewater therefore finds its way into the lake via routes such as the Nakivubo channel, various swamps and streams, direct discharge, etc. In other words, most of Kampala's wastewater makes it to Lake Victoria untreated.

Lake Victoria is the largest lake in Africa, right? Surely, by its looks it can handle all this waste. Wrong! At the moment, Lake Victoria is a sink for human, agricultural and industrial waste all along its 3450 km-long shoreline. Guesthouses, slum dwellings and industries discharge untreated wastewater into Nakivubo channel, which flows into Murchison Bay and contributes to pollution loads and depleted oxygen levels in Lake Victoria. Riding a motorboat at the point where Nakivubo channel discharges into Murchison Bay churns up a trail of black sewage sludge.

Ground water (water sourced from sunken wells and boreholes) is typically a more economical choice than surface water as a source for drinking water as it is inherently pre-filtered by the aquifer from which it is extracted. Surface water (such as that from Lake Victoria) on the other hand, is a typical raw water source used to make drinking water where it is abundant, ground water is unavailable or poor of quality. It is however, much more exposed to human activity and its byproducts. As a water source, it is carefully monitored for the presence of a variety of contaminants by water suppliers. If it is abused like Lake Victoria is, the results are alkaline conditions, excessive calcium bicarbonate, nitrates, phosphates, etc in the water.

Nakivubo Channel carries approximately 75% of the nitrogen and 85% of phosphorus nutrient load discharged daily into Murchison Bay. The high nitrogen and phosphorous levels are responsible for the excessive algal blooms seen in the bay. Now, you can work out where the green water at your tap is coming from. It is from us!

The contents of this channel eventually turn up in Kampala's taps
The contents of this channel eventually turn up in Kampala's taps.
(Image sourced from Eng. Herbert Mpagi Kalibbala)

While the onus is on NW&SC to find ways of reducing leakages (points of contamination of treated water) before the water gets to our taps, we should take plenty of responsibility for what happens when it leaves the taps. Complacency about wastewater management among us is what will kill us. Irresponsible wastewater discharge by any one affects us all. What goes round comes round. The chickens are now coming to roost!

By Ivan Kibuka-Kiguli
more from author >>
First published: September 10, 2007
The author is a pollution control equipment engineer/consultant and a proud active member of UGPulse.