I am going up to Seagull for the first time later this summer, and had a question about drinking (filtered) water from the lake.
In past trips to BWCA I’ve always drank water either straight from the lake or filtered. This is my first time going on a lake that allows motor boats on it though. Is it still safe to drink filtered water? Will gasoline, oil, other contaminants from gas motors be filtered out by a normal filter or life straw? Any other considerations for dissolved contaminants that might not be filtered out?
There will be a pregnant woman going with our group, so I am trying to be extra considerate and cautious about any potentially harmful substances in the drinking water!
Thanks!

Filtering is fine. I don’t know if it filters gas but I can’t imagine there is enough gasoline/oil in Seagull to be measurable. Especially for a trip. That water is still probably better than what comes out of your faucet or bottled water.

T

Hunter123: "I am going up to Seagull for the first time later this summer, and had a question about drinking (filtered) water from the lake.
In past trips to BWCA I’ve always drank water either straight from the lake or filtered. This is my first time going on a lake that allows motor boats on it though. Is it still safe to drink filtered water? Will gasoline, oil, other contaminants from gas motors be filtered out by a normal filter or life straw? Any other considerations for dissolved contaminants that might not be filtered out?
There will be a pregnant woman going with our group, so I am trying to be extra considerate and cautious about any potentially harmful substances in the drinking water!
Thanks!"

Since your concern is chemical contaminants I'll let you know that the water filters most commonly used for backcountry treatment are not adequate for that level of purification. They're designed to filter microbes which are generally much larger than the molecules of chemical contaminants. You will need to look into filters that use activated carbon/charcoal in order to handle chemicals.

This video, though long, will give you a better idea of what you can expect from activated carbon filters available on the market. Gearskeptic: Activated Carbon Filtration