Richard Gleeson
Northern News Services

Yellowknife (Sep 28/01) - Elevated levels of E. coli bacteria in water flushing into Great Slave Lake are seasonal problems and pose no health risks, officials say.

Analysis of samples of water flowing from storm sewers emptying into Great Slave Lake reveals extremely high E. coli levels. Lab technologist Lorelei Andrew of the Taiga Environmental Laboratory is among those who analyse water samples for private and public organizations. - Richard Gleeson/NNSL photo

"The issue, really, is every time the snow melts, you get lots of feces from domestic animals flowing through the storm sewers," the NWT's chief medical health officer, Andre Corriveau, said this week.

An intense rainfall would have the same effect, Corriveau said.

Water samples taken during and immediately after this year's spring run-off contained E. coli levels more than 100 times the accepted level for recreational use.

At least one resident doesn't share the official level of confidence, however.

"It's mind-boggling that you set limits for mines and yet this is allowed to go on in the city," said Erik Madsen, whose School Draw Avenue home is 25 metres from one of three main stormwater outlets into Great Slave Lake.

On May 10 a water sample taken from the outlet that had an E. coli count of 31,000 per 100 millilitres. The recommended guideline for recreational use is 200 per 100 ml of water.

Taken last spring, the samples formed the basis of a Department of Indian Affairs and Northern Development study for an upcoming review of a city water licence renewal application.

There are hundreds of different strains of the bacteria known as E. coli. All can be found in the intestines of mammals. One of the most toxic strains, known as 015:H7, made its way into the drinking water supply of Walkerton, Ont., in May 2000. Seven people died.

Because of the potential health risks posed by elevated bacteria and heavy metals levels, the July 2001 DIAND study was submitted to the Stanton environmental health office for a risk assessment.

The whereabouts of that assessment was unknown earlier this week. The environmental health officer who conducted is away on holidays and could not be reached.

Neither Corriveau nor the Department of Indian Affairs and Northern Development has received a copy. Residents living in waterfront homes near the outlets said they have not seen the assessment or the DIAND report.

Relying on the recollections of an official in his office of consultations with the Stanton environmental health office, Corriveau said 15 samples were taken of lake water near the outlets as part of the assessment. All samples contained E. coli counts of fewer than 10 per 100 ml. The samples were taken in July.

Corriveau did not know if all 15 samples were taken around the same School Draw outlet or from all three outlets sampled in the DIAND study.

Regular samples are taken only in areas where the public routinely swims, such as Long Lake beach.