Grey water systems offer you an easy way to save on your monthly water costs and also help the environment. While you may already be active in recycling paper, plastic and other items that have a useful second life, a residential grey water system gives you the opportunity to recycle the water you use as well! Learn more about what grey water is, how it can be re-used and whether a residential grey water system may be right for your home.

What is Grey Water?

Grey water is water that has been used previously, but is free from very harmful contaminants. You may also see grey water written as “greywater” or “gray water.” Grey water typically goes right from your house to the sewer after its first use.

It is very important to distinguish grey water from black water. Black water does contain toxic contaminants and should be sent straight to the sewer line. Black water comes from the toilet, the dish washer or any sink equipped with a waste disposal system (read on below for where grey water comes from).

Where does Grey Water Come From?

In a residential setting, grey water most frequently comes from the following places:

  • Your sinks
  • Your showers
  • Your clothes washer

If you are interested in re-using your household’s grey water, it is important to keep it grey by not using any toxic contaminants such as bleach. You can feel confident using safe natural soaps and cleaners that are labeled as earth-friendly.

How a Residential Grey Water System Works

When any household has a residential grey water system installed, the system captures the water before it enters the sewer line and re-routes it back to the house for re-use. There are different systems that can accomplish this. Choosing the right system is important to make sure you capture all available grey water and route it to the areas where it is most needed.

One way would be to connect your sinks, showers and clothes washer line to your grey water system, which then re-routes the water back into other functions, such as drip irrigation or watering for a vegetable garden, lawn or flower garden.

Handling Grey Water

Grey water is very useful when it is fresh. However, there are dangers when you try to store grey water long-term, because toxins can then build up. So any grey water you can’t use should be routed back to the sewer system for processing in the usual way. Here, it is important to set up your grey water system so you can switch between the grey water and sewer routing. This will keep water from pooling and attracting bugs or rotting roots. The more you can learn about your household’s average water usage (and how much usage could come from grey water instead) the better able you will be to fine-tune your initial system setup.

With Grey Water, Simple is Best

Grey water systems don’t have to be complex – in fact, most residential systems are designed to be simple and relatively maintenance-free (except for periodically changing the filter). Apart from the one-time cost of setting up your grey water system, actually using the grey water to water your plant life will happen fairly automatically and can potentially lower your water bill by hundreds each month, especially in the hot summer season.

Getting Started with Grey Water

Alvarez Plumbing is willing to answer any questions or concerns you have about changing your plumbing to conserve water. If you are interested in lowering your monthly water bill, contact us at