Yellowknife dump runoff may be causing Jackfish Lake algae blooms

N.W.T.'s Department of Environment and Natural Resources wants the City of Yellowknife to test run-off water at the city dump to determine if it is the source of recent sludgy algae blooms in nearby Jackfish Lake.

The department has asked the Mackenzie Valley Land and Water Board to amend the city's water licence so that it requires the city to test dump water for phosphate and phosphorous. Both cause algae blooms, which ENR says it has detected in Jackfish Lake in the last two years.

The department had asked the city for the additional testing during informal talks in May.

The city samples run-off water from stations at the dump twice a year, in June and September.

Judy McLinton, manager of Public Affairs and Communications for ENR, says that the department is gathering information "to provide a better understanding of the situation and potential inputs to Jackfish Lake."

"Algal blooms are generally associated with an increase in the amount of nutrients in water. Phosphorus is an essential plant nutrient, and its presence or absence in the water controls the growth of aquatic vegetation."

McLinton says that it is too early in the investigation to know if increased amounts of phosphorus pose a threat to the ecosystem in the lake.