AGRICULTURE and industry are leading the way in cutting down on water usage, but while this is commendable, it could also have serious implications on the amount of waste water needed to flush sewage and effluent systems.
This warning was issued on Tuesday at a meeting of the Mhlathuze Effluent Pipeline Forum.
Former CEO of Mhlathuze Water Vic Botes said all industries represented had indicated good results in terms of water saving under the present Level 3 restrictions and anticipated continued savings when Level 4 is implemented.
‘However, it must be borne in mind that the pipe systems discharging industrial effluent and domestic sewage are designed to carry enough water at a constant velocity to ensure their proper performance.
‘If less water is being consumed, it follows that less waste water is being discharged.
‘Reducing the amount of waste water being discharged has ramifications. The pipelines are gravity-fed and solids will not be flushed out.
‘It is great that people put a brick in their toilets to half the amount of water used, but again, that means so much less water to flush the sewage.’
Of particular concern was sand in effluent that was pumped into the system from sumps and discharged into the Arboretum macerator pipeline.
‘Unless a constant velocity is ensured to keep sand in suspension in the pipeline, there will be blockages.’
Other downsides of water saving include the higher concentrations of pollutants in discharge water owing to the lower dilution.
The income of Mhlathuze Water and the municipalities will also be drastically affected as clients, forced to implement restrictions, cut down their demand and improve efficiencies.
