River Pollution

Addis Ababa is a city of rivers, there are many tributaries of the Akaki River that run through the City before feeding into the Awash river and so forth into the lakes of the Rift Valley. The rivers have truly been a blessing for the residents, in fact it was the clean waters and natural hot springs that initially brought attention to the area and before it ultimately became the Capital of the country. Residents used the water for drinking, washing, agricultural purposes and for recreation, but things have since changed.

The hot springs have dried up and the once pristine rivers are now filled with plastic bags and other garbage, the brownish tinge more reminiscent of an open sewer system than a waterway: a fact not lost on those who openly urinate off bridges into the river below. The change has been gradual but cannot be ignored, the main sources of contamination are:

Industrial wastewater
Addis is home to more than 2,000 industries, (including pulp-paper, food, chemical, textile, tanneries, metal works, and mining) the majority of which are located on the banks of rivers and discharge these effluents directly.  According to the Addis Ababa Environmental Protection Authority (EPA) as much as 90% of these industries do not have any kind of treatment plant and discharge their solid, liquid and gaseous wastes untreated into the environment.

Municipal wastewater
More than 24% of households are not connected to the sanitation system, meaning instead of traveling by sewer to a treatment plant it flows through a series of roadside open ditches before emptying directly into the closest river. The city is growing at a rate far in excess to which it can provide services and the number of un-serviced households is ever increasing.

Agriculture
There are many urban agriculture projects within the city, especially along the river banks and these practices are releasing pesticides, fertilizer and livestock manure into the waterways. These run-off nutrients are a major cause of eutrophication of the rivers and lakes downstream, a process by which oxygen is removed from the waterway slowly dies.

In light of these facts, it should come as no surprise that the rivers in Addis are classified to be “badly polluted to very badly polluted” by the Slovak Technical Standard and the World Health Organization (WHO). Tests have shown that levels of cadmium, chromium, cobalt, lead and E.coli are all at levels far beyond allowable levels for human consumption.  Fortunately, the majority of the City’s drinking water comes from underground wells and unspoiled aquifer, but local farmers are still using the river water to irrigate crops. 

According to the Addis Ababa Urban Agricultural Office, 60% of the vegetables sold in the city have been irrigated with river water. Furthermore, an EPA study in 1998 showed very high levels of cadmium, chromium, copper, lead, mercury, nickel and zinc in potatoes grown on these farms. Examples in China have shown a direct correlation between the use of wastewater for irrigation and an increase in liver cancer as pollutants enter the food chain.

I guess that will give me something to think about the next time I am buying groceries...

Municipal waste outlet into the river

A too common scene