Routine Operations

Trigger/action levels


Routine patrol at reservoirs

Algal scums/blooms observed

Collect samples for microscopic examination, Chl a testing and toxin test; physical removal of algal scums in water

Routine monitoring of chlorophyll-a and algae counts in reservoirs

Chl a exceeds 50 μg/L and sample dominated by potential toxin producing cyanobacteria, or Microcystis count exceeds 5000 cells/ml

Conduct toxin analysis, management of reservoir water quality by improving the turnover (dilution with alternative source of water and ensure there is no de-stratification)

Routine monitoring of toxins at reservoirs

MC-LR in raw and treated water exceed guideline level of 1 μg/L for drinking water

Increase toxin monitoring in source and treated water, enhance the water treatment process by introducing PAC or ozone. Utilise alternative reservoir source supply.