Q. Dear Umbra,

We use a dehumidifier in our basement. How can we use the water it collects -- drink it? Use it in the garden? For our pets?

Jean K.
Newington, Conn.

Gray water is safe for inedible plants to drink, but you probably shouldn't try it yourself. (Photo by Shutterstock.)

A. Dearest Jean,

I hereby bestow enormous thanks upon you, for you have given me an opportunity to revisit one of my favorite topics -- the ever-useful, though disgustingly named, gray water. This is an especially pertinent topic during these times of drought and other wild weather.

Gray water, as you might know, is the lightly used wastewater that comes from our showers, dishwashing, laundry, and so forth -- basically, anywhere but the toilet. (That stuff is even more disgustingly known as “black water.”) Water in a dehumidifier counts as gray water too, though it is snatched from the air instead of dispensed from our pipes. Whatever the source, it seems a shame to pour this water down the drain. It is still useful! Despite being gray or grayish! So what can we do with it?

To answer your questions: No, it is not drinkable. For you or for your pets. But it should be okay for watering plants and a few other uses, which I shall detail in a moment.

Photo by Andrew Gainer.

Wolverines are loners, and they don't like to share. They try not to hang out anywhere near other wolverines or other mammals, a social preference that some of us can relate to. And like other grumpy, anti-social creatures, wolverines do not like to share their food.

You'd think that they'd be safe by living in the coldest reaches of the planet, in the middle of snowy wastelands. But they cannot escape the pesky insects and microbes that find a way to live anywhere and that would be happy to feast on the food that wolverines have scared up. To defeat them, the wolverines keep their food in what's basically a DIY refrigerator. National Geographic News reports:

Q. Dear Umbra,

This fall, I will be going to college. One of the biggest (and most expensive) items on the list is a laptop. My stepmom and I were debating whether it would be more eco-friendly to buy a refurbished laptop versus a new one. Will a refurbished laptop place less demand on rare earth metals and those other nasty resources needed to make electronics, or should I just invest in the newest computer? Please help me settle this debate! I want to be eco-friendly!

Kristen
Chapel Hill, N.C.

Are refurbished laptops the greener way to go? (Photo by Wayan Vota.)

A. Dearest Kristen,

Congratulations -- what an exciting time! And my, how things change: In my day, “the list” included things like “towels and flip-flops for the shower.” Those were essentials.

In fact, speaking of essential, is it crazy to think one could get by at college in the current era without a personal laptop? Is part of our national economic and environmental crisis due to the fact that this country’s 20.4 million college students are expected to buy -- and then forced to dispose of -- a piece of electronic equipment rendered obsolete before they graduate? Are these notions of mine demented?

Demented. So a laptop you must procure, and a laptop you shall have. While I understand your stepmother’s instinct to get the best and bedazzlingest technology, a refurbished model can actually satisfy that need and assuage your eco-concern -- if you do some smart shopping.

This Barcelona flat might be our favorite tiny apartment yet. Everything is just so cleverly tucked away! The dressers are inside their own drawers that slide out from under the raised bed. The table and the bench slide back and forth on the wall, so they can be pulled apart for use or stacked for a smaller footprint. And the piece de resistance: Underneath the bench is a full-size bathtub.

Pack it up, pack it in.

Editor's note: Umbra's on a hard-earned vacation herself, so instead of her regularly scheduled column, we're pulling this gem out of the archives.

Stuck in a cubicle, straining your neck for a glimpse of summer sun? The 9-to-5 routine can be particularly irksome when the weather's lovely. Daydreaming about future vacations can help ease the strain, and a little forethought can go a long way in making trips more sustainable. A Washington state reader wants to map out future travel with her husband:

"We’ve had the typical RV fantasy as we do love to travel, but we worry about the gas consumption and resulting emissions that would come of that route. We could tour around in our Prius and stay at budget hotels (and probably break even monetarily), but we’re concerned with their poor laundering, heating/cooling and other consumption choices. Of course we love foreign travel, but the emissions from airplanes are hard to justify, even with purchasing carbon offsets. Any ideas ... ?"

Read on for Umbra's answer. She advises not to fret about hotels and recommends the Union of Concerned Scientists' guide to lower-carbon vacations.

A little fuzzy on how to stay clean-shaven yet green in a disposable razor culture? Umbra's here to offer tips on warding off stubble trouble while shaving away waste.

This year marks the 10th anniversary of our Ask Umbra advice column, and to celebrate, we’re pulling a favorite gem of eco-advice out of the archives each week.

Q. Dear Umbra,

We are in the midst of a heat wave. I have a window unit air conditioner in my tiny apartment. There is an "energy saver" option that shuts down once the temp reaches the desired setting (generally 79 degrees), then starts back up again when the mercury rises. It's been so hot that it seems to only take a few minutes till it fires back up. Is this really saving energy?

Emily
Brooklyn, N.Y.

Photo by Jan Tik.

A. Dearest Emily,

With hope, the heat will have broken by the time you read this. But we all know it will rise again, and we'll have plenty more days when we can hear the entire country lean back in its chair, wipe its brow, and mumble, "Hot enough for ya?" Except here in Seattle, where we get approximately one hot day a year, usually the third Tuesday in September.

Before we get to your question, a few eye-opening facts about America's love of indoor climate control: In the late 1970s, 23 percent of American homes had some form of air conditioning; today, 87 percent do. We have become so addicted that 9 out of 10 new homes are built with central air. We spend $40 billion a year air-conditioning our buildings, says the EPA, and cooling our homes accounts for 17 percent of household energy use.

Doesn't pass the smell test: Should we leave eco-friendly kids up to their own devices on hygiene?

It's great when kids warm up to green living. But what happens when they get fresh with you on not-so-fresh habits? From reader Kathy:

"My two sons, age 12, shower twice a week, with prompting. I told them most Americans shower daily, and one of them stated flatly, 'That’s crazy. It’s wasteful.'

I am all for saving water, but I told them it depends on the situation. What is your opinion -- should I respect their Earth-loving impulses or, as they begin their teenage years, teach them to pay more attention to personal hygiene?"

Read on for Umbra's answer. She offers praise for raising such eco-friendly kiddos and suggests ways to help the boys feel better about showering -- from turning down the water heater to joining the shampoo-free movement.

This year marks the 10th anniversary of our Ask Umbra advice column, and to celebrate, we’re pulling a favorite gem of eco-advice out of the archives each week.

Dearest readers,

Some people celebrate Independence Day with parades, cookouts, fireworks, and reflections on our nation’s grand traditions. I celebrate it by sorting through my inbox to make sure I have answered your most pressing, timely questions -- before they get dustier than Jefferson’s wig. Read on for a new batch of truths, which you might or might not hold to be self-evident.

Q. Dear Umbra,

I love grilling in the summer, but what is the best source of fuel? Propane is yet another gas, and though the containers can be refilled, there is a lot of waste. At the same time, charcoal doesn’t seem like the best bet either. What’s the cleanest fuel for my fire-roasted fun?

Brianna C.
Sacramento, Calif.

Appearances can be deceiving.

The Natural Resources Defense Council (NRDC) has released its annual "Testing the Waters" report, an overview of the nation's beaches.

You'll want to read this before taking a dip.

Over the 22 years the NRDC has created the report, 2011 saw the third-highest levels of beach closings and advisory days. What does that mean? What, exactly, would you be swimming in?

Most beach closings are issued because beachwater monitoring detects unsafe levels of bacteria. These unsafe levels indicate the presence of pathogens -- microscopic organisms from human and animal waste that pose a threat to human health. The key reported contributors of these contaminants are (1) stormwater runoff, (2) sewage overflows and inadequately treated sewage, (3) agricultural runoff, and (4) other sources, such as beachgoers themselves, wildlife, septic systems, and boating waste.

Oh, neat. Here's how that pollution has varied as a cause of beach closures over the years: