Nova Scotia

Blue-green algae blooms common problem for Dartmouth region

Hot, dry weather has caused blue-green algae to form in two Dartmouth lakes and the area's water supply.

New bloom found in the Lake Major water supply this week

Blue-green algae, or cyanobacteria, can produce microcystin, a toxin that can be harmful to humans and animals. (University of Alberta)

Hot, dry weather has caused blue-green algae to form in three Dartmouth-area lakes, including one that supplies water to tens of thousands of people.

Halifax Water said Thursday that a new bloom of blue-green algae was found in the Lake Major watershed, which serves about 103,000 residents in Dartmouth, Cole Harbour, Eastern Passage, North Preston, Westphal and Burnside.

"The blue-green algae that we've detected at Lake Major is not of a toxic form whatsoever," said James Campbell, the spokesperson for Halifax Water.

The utility company said the level of the toxin produced by the algae remains below Health Canada's maximum acceptable concentration and the water is still safe to drink and use.

James Campbell, the spokesperson for Halifax Water, said the blue-green algae in the Lake Major water supply is not toxic. (CBC)

Halifax Water said in a news release it is monitoring the water quality at Lake Major with Nova Scotia Environment and Public Health and any changes will be communicated to the public.

Lakes Banook and Micmac

A blue-green algae risk advisory was issued for Lake Micmac earlier this month, which was later extended to Lake Banook. 

Sam Austin, the councillor for the area, said the lakes have been closed for about two weeks.

"It's hard to picture Dartmouth without the lakes and it has been an ongoing issue," Austin said.

Sam Austin, the councillor for Dartmouth Centre, said staff haven't seen any blue-algae blooms in lakes Banook or Micmac recently. (CBC)

Austin said he's hoping the advisories will be lifted soon but it depends on what information comes back from water testing.

He said the samples from the water were sent to a lab locally to check for toxins. If those results come back negative, the lakes must have no blooms for at least seven days before the advisory can be lifted. 

"The last time I talked to staff, we haven't seen any [blooms] so hopefully we'll be in a position to lift the advisory soon," he said.

But in an email, a spokesperson with the Halifax Regional Municipality said algae blooms have been spotted in Lake Micmac over the last few days and on Friday.

Hot, dry weather has caused blue-green algae to form in two Dartmouth lakes and the community's water supply. 1:57

Clarifications

  • An earlier version of this story said the blue-green algae was toxic. Halifax Water says the algae found in Lake Major is currently non-toxic.
    Jul 16, 2020 11:28 AM AT

With files from Pam Berman

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