How bad are these cottage activities for your lake?

This article was originally published in the May 2016 issue of Cottage Life magazine.

You asked: how bad is it for my lake? Ratings: 1 (whateves) to 5 (superbad).

Fireworks

Badness level 2.5: Bad like a Katherine Heigl movie. Your lake will recover. But it might want two hours of its life back, dammit!

Why: Some studies found perchlorate, a chemical in pyro­ technics, present in lakes adjacent to fireworks displays— but it was undetect­able over time. (In one study, the per­ chlorate was gone nine days later.)

What to do: You can use perchlorate­ free fireworks (but they’re more expensive).

Urine

Badness level 2: Mostly, it’s just plain gross.

Why: Urine is almost all water, but it can contain traces of pharmaceuticals, and it does contain nitrates. In theory, a lot of pee in a small lake could promote algal blooms. (In 2012, Time reported that swimmers in Germany’s Eichbaum Lake killed 500 fish by peeing too much.)

What to do: Go before you hit the water. Even little kids can learn this.

Golf balls

Badness level 4: Bad if you don’t remove them.

Why: According to research from the Danish Golf Union, golf balls release heavy metals such as zinc, and take up to 1,000 years to decompose.

What to do: Collect your balls, Tiger. Or, obviously, don’t hit them into the water in the first place.

DEET and sunscreen

Badness level tbd: Badish, partially because the amount that washes off your body is small.

Why: Research shows that DEET and some components of sunscreens can accumulate in the swimming areas of lakes. The impact? “Minimal risk” according to a lot of scientists, but the impact is still under investigation.

What to do: Stay tuned! Meanwhile, wear products as directed, not to excess. Apply DEET; don’t marinate in it.

Soap

Badness level 5: Bad. To the bone.

Why: It’s well docu­mented: shampoos and soaps add phosphates to the water, which increases nutrients and pro­ motes the growth of algae.

What to do: Use EcoLogo-­certified products, and don’t lather up or rinse off in the lake.