Senwes Scenario October/November | Page 18

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 16 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