Liesbeek River pollution concern

EXPERTS disagree on the seriousness of an exponential rise in e.coli bacteria in the Liesbeek River as measured opposite the Hartleyvale Stadium, which could indicate that Observatory’s creaking sewerage system is becoming dangerously old.
On the one hand, City officials seem to downplay the significance of the increase in the e.coli count, describing it to a recent Sub-council 15 meeting as “minor” and which is to be expected from a developed area.
On the other hand, Dr Kevin Winter from the Environmental and Geographical Science Department at the University of Cape Town described the increase measured from the year 2000 as an “eye-opener” and a “worrying factor”.
According to a report by the City’s directorate of Roads and Stormwater, water samples taken from the Liesbeek opposite Hartleyvale contained 90 to 950 “colony-forming units” of e.coli. And by 2012 the count had risen to a range of between 100 and 450 000 units.
The official report seems to downplay the increase, saying "the worsening trend is off a very low base". However, the report does state that the river is too polluted for swimming or fishing. The report says there are no environmental implications of the increase and does not recommend that any action be taken. It says that the Hartleyvale monitoring point is the only place shows an increase in e.coli.
In stark contrast, Kevin says: "The graph from the Scientific Services is excellent and a wake-up call for the Friends of the Liesbeek (an environmental organisation to which he belongs). We've taken our eye of the ball. The trend is disturbing."
He reckons the main reasons for the e.coli increase are “surface runoff (rainwater running into the river), storm water drains and from broken or leaking sewerage systems”.
The City report says the increase is "probably the result of periodic failures of an aging sewerage system in a very old catchment area."
However Kevin also reckons that "It is possible that efforts to improve habitat, for example allowing islands to form in the lake, means that there is more roosting grounds for water birds. A rise in e.coli may well be due to an increase in the bird population; an unintended consequence of improvements to the Liesbeek".
Experts says that the presence of e.coli is not necessary the problem, but that it is a useful measurement of the potential presence of other disease-causing organisms. Kevin said: "E.coli is not the problem, since our bodies have millions of e.coli in them. However, the e.coli is an indication of risk because pathogens are most likely to be associated with increasing counts."
However, e.coli may affect those with weakened immune systems in potentially developing a fatal type of kidney failure.