Cleanliness of Lakes?

[TurboHike]

DO NOT wash clothes or use soap in lakes. That's how they become contaminated with chemistry no filter will remove. Take a container of water away from the lake (minimum of 200 feet) and wash off sunscreen etc before doing any swimming. Don't urinate in the lake. Don't urinate near the lake.

Some of the waters in the Sierra are now showing signs that people are urinating too close, or in, the water -- low levels of medications that people take (antidepressants for example) are showing up in the testing that is sometimes done to monitor water purity. Sunscreens and other chemicals are not removed from water by backpacker filters.

As has been pointed out to you more than once on the Backpacking Light forums, you really ought to do your homework on water treatment. The sweeping assertions in bold simply aren't true. The carbon filters employed in devices such as those sold by MSR adsorb many chemical contaminants, including herbicides and pesticides. Where they fail is with high chemical concentrations and heavy metal contamination. Users are advised to avoid water sources such as mining tailing ponds or those near agricultural operations. Few if any lakes in the Sierra backcountry are chemically contaminated to such an extent.

The biological and ethical case for LNT principles is a strong one. There is no need to resort to "alternative facts" in support of it.

I understand your point, but many backpackers do not use filters with carbon media. The lightweight filters like Sawyer mini, Sawyer squeeze, and MSR trailshot do not use carbon. They use hollow fibers. Even filters that DO use carbon often use so little carbon that only a small fraction of chemicals is actually removed. So while I think you are technically correct, in practice your comments will not apply to most lightweight backpackers. These folks will still need to worry about chemicals in the water.

[Wandering Daisy]

Due to warming waters, a lot of lakes now have a film of algae and mud and other non-giarda contaminants. I no longer jump into lakes; I do a bucket shower on the shore, skimming the clear water from the surface. Same with washing clothes- often they end up dirtier after "washed" if done directly in the lakes. I now wash clothes in my cooking pot. I do not use soap. The freshness of washed clothes comes more from drying in sunshine than using soap.

Seems like getting giarda from clothes is not likely, unless you suck your shirt sleeve. Washing hands before eating is the best solution, not just for giardia but all sorts of other nasty dirty things getting into your system.