I fucking hate swimming laps in a pool during official lap swim hours, with all your "rules" and your system keeping me down. And it just doesn't make sense to go into some nasty indoor crowded box when I'm literally surrounded by miles of beautiful open water.
But there's a bit problem with this idea. Seattle is shitting on my face.
The fall/spring, when a wet suit would help, is when it rains. When it rains, the sewers overflow and drain into the lake. Then you get itchy bumps and vomiting and so on.
Seattle is basically doing nothing about it. There are some little programs to do "rain gardens", but those are sort of like using a tampon to stop elephant piss. What we need is serious fucking civil engineering. ("rain gardens" are also better known as "mosquito breeders"; we Houstonians are always amazed and delighted about the lack of mosquitos here; it's because Seattle is hilly and surrounded by lakes so the water doesn't pool, but the city is doing their best to ruin that). (a much bigger impact than piddly residential rain gardens would be to outlaw concrete parking lots; grass/gravel/lattice parking lots work perfectly fine for holding cars).
Of course this is a problem that is occuring all over the US. I hear NY has a major sewer problem as well. The population and development of most US cities has outstripped their infrastructure, and in our shitty faux-libertarian plutocracy of course there's no money for basic civil engineering. Only the heavy hand of EPA orders is forcing these dumb ass local governments to do anything.
The real solution is something like :
1. Separate the sewage and rain runoff. Run sewage to treatment plants in a closed system so it can never get out. (probably not realistic; alternatively, add a new clean storm water only system)
2. Since you will allow non-sewer storm water to drain to the lake, make the pollutants that run off to the lakes illegal. Fertilizers, pesticides, etc. everything that's water soluble and washes into the lakes is illegal right fucking now.