I used to bathe my daughters together when they were babies and toddlers.

To tell you the truth, I didn’t wash them together just to save time. I was trying to save money and water. I might still force the issue, but my 12-year-old is horrified at the thought of having her little sister see her nude.

OK, I’m kidding. But American families could save about $170 a year by retrofitting their homes with water-efficient fixtures and appliances, according to the Environmental Protection Agency.

That may not sound like a lot to some. But as I always say, when you sweat the small stuff, the money adds up.

Being environmentally friendly has a double impact. You save money and the planet. That point was driven home to me by former Vice President Al Gore’s recent documentary, “An Inconvenient Truth.” If more of us paid attention to the things we waste, we wouldn’t have as many of the global environmental issues as we’re dealing with now. Plus, we’d have a little more left in our wallets. And it’s not just being water-wise that can help you save a few bucks. What about the trash you throw away?

In 2005, U.S. residents, businesses and institutions produced more than 245 million tons of municipal solid waste, according to the EPA. That translates to about 4.5 pounds of waste for each person every day. Invite me to a party, and it’s likely I’ll go through the trash to rescue recyclable plastic and cans.

In light of my conservation mood these days, I thought I should make my annual Penny Pincher of the Year Contest a themed challenge. This year, I’m looking for penny-pinching entries that have a positive impact on the environment.

For example, one of my all-time favorite penny pinchers is Louise Meyer, of Washington, D.C. She won the first Penny Pincher of the Year Contest in 1997 by writing about how she put solar cookers on her roof and used them to fix chicken, rice, stuffed peppers and even pasta.

At the time, Meyer said she saved about $40 a month on her electric bill during the winter and $140 in summer months by solar cooking her food and by avoiding using her clothes dryer and air conditioning.

To find out more, visit the Web site for Solar Cookers International (www.solarcookers.org). For under $50 you can buy a solar cooking kit, which includes a cookbook.

At my house, I try to be considerate of our country’s hardwood forests by reusing every delivery box. I also recycle the packing material. I use labels to cover up the old shipping information.

Another previous penny-pinching champion took a plastic milk jug into the shower with him to capture the cold water that came out before the water heater kicked in. He then took the cold water and used it to fill his toilet tank to flush away his waste. By doing this, he was able to cut his water bill.

In this country, we use an average of 100 gallons of water a day at home. We could cut our water use by 30 percent. If all U.S. households installed water-efficient appliances, the country would save more than 3 trillion gallons of water and more than $17 billion dollars annually, the EPA says. And when we use less water, we reduce the amount of energy needed to supply that water.