In the wake of rising water levels, the territory's chief medical officer is advising residents of Lake Laberge, Marsh Lake, Carcross and Tagish to boil their water.

Bryce Larke told a morning news conference the threat of well water contamination is real, and residents of affected areas are being asked to protect themselves.

'We want to make sure there is no added health problems added to those areas that are affected by the flooding that has taken place.

'All of that water needs to be clean.'

Larke said his office is recommending residents looking to use their well water for drinking, cooking or brushing their teeth, bring that water to a rolling boil for at least two minutes. Failing that, they switch to a different source of water, such as bottled water, he advises.

Larke said well water can become contaminated by bacteria from the environment or from people's outhouses and septic fields, and could present a danger to human health.

The threat is larger to people who have compromised immune systems, including those undergoing cancer treatments or who have had organ transplants.

He said the advisory was brought in as the water is now reaching levels of concern.

'We received word this morning that areas of the South McClintock access road are under water,' he said.

Larke said the advisory will stay in place until after the rising water levels peak, which is expected in mid-August.

Eric Bergsma, the acting manager for Environmental Health Services, said this morning the areas of greatest concern are Army Beach and South McClintock in Marsh Lake, about 40 kilometres south of Whitehorse.

Bergsma said that even after the advisory is lifted, people should not drink water from their wells until it has been properly tested.

'We're asking people to boil water until such time they have a satisfactory drinking water test result,' he said.

Water samples can be taken to #2 Hospital Rd. in Whitehorse for free testing, he added.

Bergsma said that sewage systems in the area are also a concern.

'If the septic system is flooded, it may not work. That sewage will just back up into your house ... it can carry organisms with it that can cause certain disease,' he said.

'Direct contact with sewage is to be avoided.'

Bergsma said outhouses at risk of being flooded should be filled in with dirt to avoid having their contents washed away.

Port-o-potties, which can be rented or purchased, should be used if outhouses or sewage systems are compromised, he added.

Doug Caldwell, a spokesman with the Yukon government's protective services branch, said Tuesday water levels have now surpassed the 2004 benchmark, when a flood alert was issued.

'We exceeded the 2004 level this morning by 8.4 centimetres. The historic 2004 levels were 656.783 metres,' he said. (See story below.)

Caldwell said he's concerned about this weekend, as more rain is forecast for Friday and Saturday in southern Yukon.

On Monday, according to Environment Canada's Bill Miller, Whitehorse experienced record rainfall levels.

'Whitehorse airport received 18.8 mm of rain (Monday) making that the heaviest rainfall for July 16th recorded since records began back in 1942,' Miller said in an e-mail.

'We have recorded 50.0 mm of rain so far this month, beating the average for the month of 41.4 mm.'

Caldwell, meanwhile, said his office is preparing evacuation recommendations for the area as a precaution should the water levels continue to rise.

'As the situation dictates, we're looking ahead in preparation that we may need these materials.

'We're still a month away from peak.'

Caldwell said there are some concerns about recreational boating in the Marsh Lake area as it's leaving wakes which pounded the shore and could be dangerous to boaters who may hit floating debris.

Mike Larsen is spearheading the Marsh Lake sandbagging efforts. He said earlier this week he has found a truck tire that was put in the lake and is asking residents to use sandbags, not other materials, to battle swelling water levels.

'I'd like to spread the word out to people in the area not to put truck tires in the water, it acts as a battering ram.'

Caldwell said the government's sandbagging efforts were extended Tuesday with sand and sandbags being sent to the Lake Laberge area.

He said his office is now searching volunteers in that area to help with the effort.

'We're looking for local residents with local knowledge.'

Anyone available to help out with the sandbagging efforts should call Larsen at 660-4610 in Marsh Lake, Dennis Bouchard at 399-3572 in Tagish and/or Wesley Barrett at 821-4251 in Carcross.

People looking to help out in Lake Laberge should call 667-5220.