You’ve probably heard the expression “as dull as dishwater,” but that gray, suds-filled substance is anything but dull. Gray water, as it’s known, can be harnessed, recycled, and boost your eco-credentials while potentially saving you money.
But what is gray water, and how can we make use of it?
What is Gray Water?
Gray water is water that’s already been used in your home for some cleaning task. This could be from the washing machine, the sink, bath, or shower—anywhere water and soap meet, really. If you’ve ever washed a load of dishes by hand or cleaned your clothes in the bath, you’ll see where the name comes from.
Most of the time, this water is allowed to rush off down the drain into the local system, where it’s conducted away for treatment. After treatment, it can re-enter the water cycle and, eventually, be reused. There’s no such thing as “new” water, after all.
Gray water systems in the home skip this step. Rather than draining away the water from your sink, they catch it, treat it, and let you reuse it in the house. It won’t be perfectly clean, and we certainly wouldn’t recommend drinking it, but it still has its uses. These include:
- Flushing toilets
- Irrigation systems in the garden
- Washing outdoor areas or vehicles
- Industrial and commercial applications
Gray Water vs. Black Water
Not all household water is suitable for reuse. The water from toilets and other hazardous waste sources is called black water, and there’s nothing that you can do with it on a domestic (or even commercial) scale.
Black water has to be carefully treated at dedicated sewage facilities or through specialist septic tanks. After treatment, it can be discharged out into the water cycle again, but it’s really not much use for anything else.
The Benefits of Using Gray Water
Having answered the question of “what is gray water?” and some of the things you can do with it, what are the key benefits? Why go through the effort of collecting, cleaning, and reusing what is effectively a waste product in a dedicated gray water system?
Environmental Benefits
The primary benefit of installing a gray water system is that it reduces your environmental impact.
Reusing water means that you’re drawing less from the local supply. This water needs to be collected, treated, and pumped, all of which has a certain environmental impact attached. By reusing the water that you do pull from the system, you’re cutting the amount and, therefore, the negative effects you contribute.
Not only are you reducing your impact on the supply side, but you’re also cutting your impact on the other side. Wastewater is treated before being discharged into waterways, and, just like on the supply side, this has both financial and environmental costs. If you can get two uses out of the same drop, that’s half the impact of just letting it drain away.
Sustainability
As well as these direct reductions in environmental impact, harnessing gray water can encourage other eco-friendly activities. Gray water embodies the mantra of “reduce, reuse, recycle,” and, when taken in concert with other activities like composting, could significantly boost your sustainability goals.
Cost Savings
Gray water doesn’t just offer environmental savings; it can help reduce your financial outgoings too. No one wants to pay more than they have to on their utilities, and reusing wastewater can be a great way to cut that particular bill.
Rather than drawing more fresh water from the supply and spinning the dial on your meter, gray water systems offer value through reuse. If the task doesn’t require absolutely sparkling, clean water, why pay for it?
Reduction in Wastewater Impact
Anyone who pays attention to the news will have heard of the impacts of wastewater not being properly dealt with. From sewage-filled lakes to rivers foaming with detergent, wastewater management systems can often become overloaded.
Reducing the amount of water that finds its way down the drain by reusing what can be reused cuts the amount that needs to be processed. In turn, this reduces the impact on local water systems and their ecosystems.
How Gray Water Systems Work
Getting these advantages takes a little clever engineering, but the results speak for themselves. A typical gray water system consists of elements to deal with:
- Collection: A series of pipes that take the water from sinks, baths, and washing machines to a gray water well.
- Treatment: The water is filtered, removing particles of food and the worst of the dirt.
- Distribution: The gray water is then redistributed for flushing, irrigation, or washing outdoor areas as needed. This generally involves a pump but could be as simple as having a dedicated dry well for recharging the groundwater around your home. Other elements could include things like a three-way valve that allows you to switch between clean, fresh water and gray water.
Manual vs. Automatic Systems
Gray water systems generally come in two basic varieties: manual or automatic. The stored water will generally need to be pumped to where it can be of use, and whether it’s an electric or hand-operated pump is the key difference.
- Manual systems: Great for occasional usage, such as filling a bucket to wash the car.
- Automatic systems: Allow other uses, like connecting a hose for power-washing or filling a toilet cistern.
On top of these two types of systems, there is also a totally passive option that can be used for irrigation. This works much like a dry well, where the buildup of pressure forces the gray water out into the surrounding soil little by little.
Is Gray Water Safe?
Gray water is, by definition, dirty water. This means that it has to be used carefully; we certainly wouldn’t suggest drinking a glass of it.
It will have a certain level of contamination in the form of soap, detergents, and food particles. These impurities must be filtered out as much as possible to allow safe usage. This could involve passing the water through a series of ever-finer filters or chemical treatment. Exactly how filtered and clean the water must be will vary between usages and by local regulations.
Regardless of how well filtered your gray water may be, it will always have a certain level of contamination. This means that it’s not potable (it can’t be used for consumption) and is best left for dealing with dirtier tasks, including:
- Washing vehicles
- Cleaning patios and outdoor spaces
- Irrigation
- Flushing toilets
Regulations and Considerations
Gray water usage rules vary from place to place. Some local authorities may prohibit its collection and use entirely. It’s vital that any gray water collection and distribution system meets local regulations to the letter. These rules are in place for public health, and violations may come with hefty fines.
Regulations will cover things like the use of three-way valves, acceptable uses, filtration requirements, and all the other elements of reusing water.
These rules are constantly being updated on both the state and local levels, so it’s worth consulting the EPA guidelines for your area before considering investing.
Installing a Gray Water System
Installing a gray water system that meets your needs, and the rigors of local plumbing codes can be a complex task. Therefore, it’s important to bring in experts. A local plumber with experience in these systems will be best placed to guide you through the process.
Depending on how complex your system is, costs could vary between as little as $700 for a simple well to over $20,000 for a whole-home system with all the bells and whistles. Exactly how much you need to spend will depend on what you want to use the water for and how much you need.
Regardless of how simple or complex your chosen system is, its installation is a job for a professional plumber. Not only will they be able to offer advice on maximizing the benefits of your gray water system, but they’ll also provide a guarantee.
As gray water is contaminated with soaps, detergents, and other substances, managing it effectively is vital. Consulting with experts gives you the peace of mind that you’re staying on the right side of the law and that your environmental efforts are truly worth it.
Conclusion
So, what is gray water? It’s an effective way to save money, help the environment, and make the most of a precious natural resource.