Consultant Bob Rutherford says the problem of algae bloom is spreading at Lake Micmac. ((Bob Rutherford))

The depleted oxygen levels of a stream in Dartmouth continue to pose contamination problems for Lake Micmac, the lake it runs into, an independent environmental consultant says.

"This is not what we want for the bass and the trout that live in here," said Bob Rutherford, a river specialist, indicating the green dots on the surface of the lake.

The blue-green algae bloom began last month near the spot where Grassy Brook spills into Lake Micmac, near the Dartmouth Crossing construction site where Rutherford's been working.

Grassy Brook begins at the Burnside Industrial Park, where nutrient-rich runoff from piles of peat materialhave leached into the stream,depleting oxygen levels, he said.

One of those piles has already been cleared away, according to Tony Blouin, an environmental manager for the Halifax Regional Municipality.


The green water is from Lake Micmac. ((Bob Rutherford))

"We have been sampling the brook since that happened and it does appear the oxygen levels are improved," Blouin said.

Human concerns

But because the algae bloom is showing up at the other end of Lake Micmac, Rutherford worries it will be back next spring and could spread to Lake Banook.

He worries about human concerns should the algae problem grow.

"The toxins are nerve toxins, liver toxins, and they quite often give you a skin rash," he said.

Rutherford called Health Canada last week toask officials to conduct tests, but he said officials replied that they were not responsible for testing.

Blouin said there will be ongoing tests at both Grassy Brook and Lake Micmac, but added it's difficult to rid a lake system of algae bloom.

"It's always hard to treat that after it's happened," he said, adding some of the nutrients and phosphoruswill be flushed out naturally over time.