The Niagara Region is closely watching drinking water for any signs of blue-green algae.
A small quantity of blue-green algae was discovered upstream in the reservoirs serving the DeCew Falls Water Treatment Plant.
The blue-green algae was first observed on Friday, Aug. 20.
Microcystin, the neurotoxin released by blue-green algae, has not been detected during daily testing of the water leaving the Decew Falls Water Treatment Plant over the last few days.
Therefore, there is no risk to human health at this time.
The blue green algae is being removed to minimize the risk of it multiplying.
Since 2016, the Region has enhanced monitoring for both blue-green algae and the microcystin toxin across all water treatment plants.
This includes routine visual inspection of the intakes and reservoirs to all six water treatment plans, as well as weekly testing for microcystin in the water before and after treatment.
Over the past two weeks, very low levels of microcystin have been detected intermittently in all of Niagara’s water treatment plants.
Fortunately, the concentrations of microcystin have all measured at less than 2% of the amount permissible by the Ontario Drinking Water Standards.
Officials say the water from all Region water treatment plants remains safe to drink.
After the first detection of microcystin, Niagara Region moved to daily testing, but testing is slowly returning to a weekly frequency in locations where microcystin has been undetectable for several consecutive days and no blue-green algae has been seen.
Water treatment processes have also been adjusted to neutralize and remove toxins before they enter the water distribution system.
Blue-green algae, known as cyanobacteria, can sometimes produce a toxin that is a risk to health.
Blue-green algae occurs naturally in fresh water lakes, ponds, rivers and streams in late summer and early fall.
Current warm weather has made blue-green algae more prevalent in many parts of North America, including in Lake Erie which indirectly feed Niagara’s water treatment plants.