Blue-green algae (cyanobacteria)

Telling you all you need to know about Blue-green algae and answering your top questions / busting myths

What is blue-green algae and what are the risks to me?

Blue-green algae are a type of bacteria called cyanobacteria; they are naturally occurring but can produce toxic chemicals that are very harmful to people causing skin rash, sore eyes, vomiting and diarrhoea.
In severe cases, exposure can result in fevers and liver damage.
Blue-green algae is particularly dangerous to dogs due to their small size and how they groom themselves.

Does it just appear in the summer?

Algae is present in the water all year round, but as the weather gets warmer their concentrations increase significantly.
A sudden increase in algal numbers is known as a ‘bloom’.
These ‘harmful algal blooms’ (HABs) release the cyanotoxins and may produce scums, however the absence of a visible scum does not mean that harmful levels of cyanobacteria are not present.

Is it just found in reservoirs?

Cyanobacteria can be found in any body of water- rivers, lakes and reservoirs.
The bloom may only be located in certain parts of our reservoir and toxin levels may change rapidly.
This is why we ask people to keep out of the water on all of our public access sites and to keep their dogs safely out of the water.

But is it safe to drink?

A lot of our reservoirs are used to supply the millions of homes and businesses across our region, the water is treated before it gets to your taps so it is perfectly safe to drink when it arrives at your home.