Recent independent water tests in the Hartbeespoort Dam found very high levels of suspended solids counts threatening aquatic life and drinking water quality.
The tests were performed two weeks ago by Rotary Brits Hartbeespoort and the Wildlife and Environment Society of South Africa (WESSA) Northern Areas at nine points on the dam.
The water sampling was undertaken about 60 cm below the surface where there are stable conditions with minimal contamination.
The depth of the sludge at the base of the Hertebeespoort reservoir in three zones, varies from zero to three meters thick.
Total Suspended Solids (TSS mg/L) reveal that the dam is in serious trouble. A baseline reading of less than 50mg\L is optimal for all forms of life.
The worst contaminated areas are the Leeispruit inlet at 2964mg\L and Xanadu, at the R511 bridge, at 6918mg/L.
“Fortunately, this is filtered out by the extensive reed bed and hyacinth below Birdwood estate resulting in a reading of 24mg/L midway in the Ifafi/Meerhof bird sanctuary, making it the cleanest water entering the dam”,” said John Wesson of WESSA.
Regular monitoring and management are necessary to mitigate the potential negative impacts of high TSS levels.
Other concerns include Chemical Oxygen Demand (COD). The COD measures the amount of oxygen required to chemically oxidise organic compounds in water.
A COD of 50mg/L is considered good for aquatic life and recreational purposes. The COD in the dam ranged on the surface from 35.03mg/L to 1276.00mg/L.
High COD levels suggest high concentrations of organic pollutants that could lead to oxygen depletion.