Graywater Reuse 101
Got a Question about Graywater Reuse?
What is Graywater Reuse?
Traditionally, wastewater from your home flows either into your city’s centralized wastewater collection system or into your own septic system if you live in an area without access to a centralized sanitary sewer system. Over the years, the definition of “wastewater” in the international plumbing code has been divided into two categories, blackwater and graywater.
Graywater is defined as wastewater from bathroom sinks, bathtubs and showers, and clothes washing machines. Therefore, blackwater is defined as wastewater from toilets, kitchen sinks, and dishwashers. These are the common definitions set forth by the international plumbing code which is the approved code for many cities across the US. In comparison, graywater is relatively clean and does not require the same treatment as blackwater. Creating these separate definitions now allows the use of graywater as a water conservation opportunity since graywater does not have to be directed to the sanitary sewer or septic system like blackwater does.
In 1992, Texas passed a law allowing water from clothes washing machines to be classified as graywater. TCEQ has recently passed the proposed changes to the Texas Administrative Code Section 210 (Use of Reclaimed Water) to allow water from showers, bathtubs, bathroom sinks and clothes washing machines to be called graywater.
On a large scale, municipalities across the United States are starting to implement water reuse programs that reuse wastewater treatment plant effluent for non-potable purposes such as the landscape irrigation or cooling water. This water is called “reclaimed water” and should not be confused with graywater. These two water sources are completely different. At this time, you will mostly see reclaimed water systems supplying large users of water such as golf courses and power plants.
Even though graywater reuse is not allowed in all states, we believe that graywater recovery will grow and become legal as more states begin to contend with water supply issues.
What are the benefits of graywater reuse?
- You have already paid for the water
- It only needs a minimal amount of treatment (in comparison to black water)
- You will offset the use of potable water for landscape irrigation
- You can keep a consistent soil moisture level around your home’s concrete slab which may help to prevent the movement and cracking of your slab
Why is graywater reuse so important?
Graywater reuse is important for several reasons but one of the biggest is the fact that we are tapping out water conservation gains inside our homes so we need to start looking for other ways to conserve than through traditional channels.
The following graph shows the gains that have been achieved with our indoor water fixtures through the combination of governmental standards and innovation by fixture companies. As you can see, we don’t have much more room to go in terms of achieving more efficiency gains with our indoor fixtures. What’s next… the 0.2 gallon per flush toilet? Probably not!
This phenomenom is known as the law of diminishing returns. So where will the next revolution in water conservation take place? We believe we offer services in the areas where this revolution will take place.
How can I use graywater?
Graywater recovery systems allow you to reuse water to irrigate your lawn and landscape plants, used around the foundation of your house to minimize foundation movement, and/or be used in your toilets. This will help you save money on your water bills. Unlike rain, graywater is a constant and reliable source of water that should be harnessed. You pay for water once when it passes your water meter, why not use it as many times as possible?