If you watch "Living with Ed" on the Discovery Channel, you have probably seen a water barrel. What is it? It is simple. A barrel is placed at the bottom of the downspout on your house (multiple barrels for multiple downspouts). When it rains, the water is captured by the barrels rather than running into the sewer system.

This water can then be used to irrigate your plants and if you are the industrious type, you can even water your lawn with this water.

The benefit of such systems are two fold. First, you are saving yourself the expense of having to purchase this water from the local utility. Water may seem cheap and for the most part it is, but the numbers add up and this is a pretty inexpensive measure. And secondly, you are reducing the amount of runoff that has to be treated or is diverted into the streams and rivers. Water that falls on your house, the street and so on picks up contaminants and must be treated before it is deposited in our streams. The contamination isn't much, and minimal to the degree that watering your plants and lawn with it makes not difference, but if all this runoff and the solid waste it carries was to end up in our streams, there could be problems.

Larger systems include oversized rain cisterns or holding tanks which allow the home owner to weather any drought. A single rainfall with a standard home can yield 100 to 300 gallons of usable irrigation water.

Here in the rainy northwest, I don't think I have the area for a storage tank big enough to handle all the rain. What would I do if it fills up and we are still getting rain. I really don't have to irrigate my lawn or flowerbeds that often. Is there any way I could use this water in the house, to shower with or to wash dishes. I don't think I would ever feel safe drinking it, but if I could use it in more applications I think it would be a great thing to look into.

There are greywater systems that will allow you to use rainwater to flush toilets, wash dishes, wash laundry and even take showers. Your local building codes will dictate what can and can't be done and for many applications some level of treatment will be necessary.

As far as drinking, there would be too many steps to clarifying the water and possibly too expensive. If you had a roof that you were certain wouldn't be leaving contaminants or toxins in the water, then you might be able to treat the water more easily for drinking purposes.

Is it really safe to bath in greywater. My understanding of greywater doesn't sound like it would be too nice to bath in. Is there a difference with what you are saying?

I think greywater and rain water collection devices are a must in any new green home. I think that as home filtration systems become more readily available and the quality of output improves, more and more people will install them and find more and more uses for the water it renders. Someday it may even be the norm to drink the water you treat and cut down on domestic waste water flowing to treatment plants. The black water treatment thing is a bit different and I don't know how to resolve that.

I know that in some less developed countries, there is substantial development of wastewater to potable water system development. The idea sometimes turns the stomach of many Americans as we have "readily available" sources of water at the touch of a fingertip in many cases. Water filtration technology is out there. Think about your local water treatment plant and understand that just like computers, this technology can be made smaller and more portable and eventually to the point where all water is self sourced with the municipal system handling larger applications and backup concerns.

The whole greywater thing kind of creeps me out. I just don't think it could really be all that safe. The water has been used and "dirtied". Isn't there a chance that it could end up in drinking water and other sources of water that could be harmful? Where do you store greywater anyway?

greywater systems are assembled and function so as to keep clean potable water separate from the greywater. It should also be noted that greywater excludes certain waste streams that contain dangerous bacteria. The water from your toilet, kitchen sink (garbage disposal), and sometime your shower will not enter the greywater system. There also varieties of ways to use the stored greywater. Most applications include toilet flushing and irrigation. Some applications with extra water treatment and UV cleaning will include showers and hand washing. Only in extreme applications or environments where water scarcity is a major problem with greywater be used for potable water (VERY RARE).

Greywater is stored in tank, cisterns, underground sealed tanks, etc. Its all about the application and the amount of water being retained. A greywater system may also be used in concert with a rainwater collection cistern which requires a much larger holding tank.