AGRICULTURAL
Pollution in the Vaal River reaches a
CRITICAL STAGE
How can irrigation farmers improve
the quality of the water?
Pollution levels in the Vaal River have reached a critical stage according to a report
issued by Rand Water recently. The high E-Coli levels are creating serious problems for
producers who have the right to withdraw water from the Vaal River and catchment area.
But how can the irrigation farmer improve the quality of his allocated water in order for it
to comply with acceptable norms so that it can be used for irrigation and livestock?
By Juan Booysen
Hinterland: Head Irrigation
T
he Vaal River system supplies
water to 60% of the economy
and 45% of the South African
population and a task team will
have to be established by the Department
of Water Affairs to address the problem
and to find solutions. The capacity of the
purification plants of some of the local
municipalities is being exceeded by
between 90% and 100% and will have to
be upgraded as a matter of urgency.
The main reason for the pollution
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SENWES SCENARIO | SUMMER 2018
of the Vaal River is the neutralised but
natrium-high acid content of mine drain-
age water being pumped into the Vaal
River by the mines. Another factor is the
untreated or partially treated sewage from,
in many instances, sewage processing
plants not being maintained, which is also
running into the Vaal River. The sewage is
a major health risk.
E-Coli counts are an indication of
the presence of sewage in rivers. Tests
done by Rand Water indicate clearly that
the E-Coli levels are unacceptably high.
E-Coli counts of 200 - 400 per ml already
represent a significant risk of gastrointesti-
nal disorders. Where the Rietspruit meets
up with Lochvaal, the counts are as high
as 57 940 per 100ml.
Local municipalities acknowledge the
dilemma, but explain that the cause of
the problem is old and poorly maintained
infrastructure and human conduct.
The challenges of obtaining additional
water consumption rights from the Vaal
River and catchment area have been
significant in the past, but a new element
has now been added. Irrespective of
whether the consumer is in possession of
a Section 35(1) or Section 35(4), which
gives him the right to withdraw water from
the Vaal River for irrigation purposes, the
quality of the water as irrigation source, is