Being clean isn't always green, especially when it comes to laundry. The dirt: The average household does 400 loads a year, consuming 13,500 gallons of water.

And most laundry detergents contain solvents, optical brighteners, colorants, builders, and surfactants-in short, pollutants. Washing machines also expend lots of energy, especially when you use warm water. Dryers are even worse, consuming, on average, 875 kilowatts per year-6 to 10% of total residential energy use.

The good news: A few easy changes will make a huge difference:

• Start by switching to an environmentally friendly detergent.
• And when you're ready for a new machine, choose one with the Energy Star label: It will use 30 percent less energy than a regular model and save more than 7,000 gallons of water a year.
• Run only full loads and use cold water whenever possible: About 90 percent of the energy used washing clothes goes to heating the water. For lightly soiled laundry, cold water is just as effective as warm water, and it prevents colors from fading.
• Clean your dryer's lint trap before each load to increase air circulation and energy efficiency.
• Better yet, hang clothes to dry. The sun breaks down stains, won't wear out your clothes the way a tumble dryer does, and doesn't cost a thing.