Various components of a greywater system outside of a building

Many homeowners are increasingly interested in improving the sustainability of their homes, and a significant consideration is water management. One system for water management is a greywater system, but does using this system make a difference?  

This article will discuss everything you need to know about greywater systems and their sustainability. We’ll also touch on the safety of these systems and describe how they work. 

So, let’s get started! 

Are Greywater Systems Efficient and Sustainable?

Greywater systems are sustainable because they reduce water and energy usage by recycling water back into the home. A greywater system can also reduce your water bill over time, making it one of the best ways to save money and make the most out of your water.

How Sustainable Is a Greywater System?

A greywater system is sustainable because it reduces the amount of water and energy households use. It can also save families money on their water and sewer bills.   

One key component of sustainable and green home building is water efficiency.

Unfortunately, water is a limited resource, and using too much is a serious issue.

According to the Environmental Protection Agency, the average American uses approximately 82 gallons (310.4 L) of water daily. 

Even something as small as a leaky faucet can promote excess water use that is wasteful and expensive. For more information, check out our article on leaky faucets

A dripping chrome faucet.
A leaking faucet can waste a lot of hot water over the course of a year.

One of the most efficient ways to reduce water consumption is to reuse greywater.

Greywater is household wastewater that can be recycled for reuse and has no possibility of fecal contamination. 

It includes the water coming from: 

  • Sinks 
  • Showers 
  • Washing machines
  • Dishwashers 
  • Bathtubs 

Water coming from household appliances accounts for approximately 70% of domestic water consumption.  

A greywater system will redirect the water for irrigation instead of allowing it to flow into the sewer system.

Redirecting wastewater means less water is wasted for irrigation, which is essential because as much as 50% of irrigation water is lost to evaporation or runoff.   

According to a study by the International Journal of Energy and Water Resources, a greywater system can reduce as much as 58.2% of hot and 30.6% of cold water use.

These savings reduce pressure on local water reserves. Reusing greywater can save up to 13,209 gallons (50001.50 L) of drinking water per household annually. 

Water is a limited resource, so any system that allows people to use less can help them reach their sustainability goals. 

Not only does a greywater system reduce the amount of water in use, but it also results in serious energy savings.

For example, in California, if 10% of imported water were replaced with greywater using a greywater system, the state would save 80 million kilowatt-hours of energy annually.

As much as nine percent of carbon emissions from the United States come from water transportation, and greywater systems reduce the need for this kind of energy usage. 

There are a lot of questions and skepticism surrounding greywater systems, but it is a sustainable method of reusing water that benefits everybody.

If you have more questions, we recommend reading our article on what greywater is used for today.       

Does a Greywater System Save Money?

Greywater systems can reduce water and sewer costs, although more complex greywater systems can be expensive to install.

Additionally, there are maintenance costs associated with these systems. 

Many people, households, and businesses want to reduce their carbon footprint and be more sustainable.

However, the upfront cost is typically the main concern with more sustainable systems. Luckily, greywater systems can also help households and businesses save money over the long term, so the upfront costs are worth it.

Office buildings, hotels, malls, and other large establishments have the most potential to reach significant savings, but even individual households can save money by switching to a greywater system. However, there are some initial costs to consider. 

You’ll likely need to consider the following expenditures when installing a greywater system:

  • New piping 
  • Valves 
  • Tubing
  • Purification filters 
  • Plumbing
  • Installation costs

Some straightforward greywater systems cost under $100 and can be installed without needing experts.

However, you may want to reap the benefits of a more complex system. Installation costs will be higher in this case.

Installation can cost as much as $4,000 for a household, and more significant commercial properties are looking at an installation cost as high as $20,000.  

It’s important to remember that the installation cost, while significant, is a one-time expense.

After installing the system, you won’t be paying for additional irrigation water and the energy costs of pumping water to the sewer and wastewater treatment plant. 

A pump-fed Install installed outside a home next to the building's exterior
Courtesy of Renew.

On the other hand, you’ll likely have to pay for some maintenance costs.

In addition, some greywater systems have high-tech membrane filters that need to be cleaned by specialists, and those costs can also add up. 

Sometimes, you’ll need a permit, which may or may not come at a cost. Simple greywater systems that don’t alter the plumbing don’t generally require a one. 

However, you’ll probably need to apply for a permit if the system meets the following requirements: 

  • The system uses water from showers, sinks, and baths.
  • The system requires plumbing alterations. 
  • The system uses a pump.  

Ultimately, although there may be some maintenance costs, most people with greywater systems save money because of the reduction in their water and sewer bills. 

Is a Greywater System Safe?

Greywater systems are typically safe if you use greywater-safe soaps and other products.

Even though the wastewater contains traces of dirt, grease, hair, and other particles, these are not harmful for irrigation. 

A jar of dehumidified and greywater side-by-side on a table
A greywater sample to the left. Courtesy of Wikipedia.

You may be a bit concerned about using wastewater in your yard. After all, using the water you shower with to water your plants sounds disgusting.

However, in most cases, a greywater system is entirely safe. In addition, some of the particles found in wastewater can even provide nutrients to the soil.  

However, some of your cleaning products might not be greywater-safe.

For example, ordinary soaps and detergents have lots of salt or other toxic ingredients, such as bleach. To counteract this, you should only use biodegradable or biocompatible products.

Some common ingredients you should avoid include: 

  • Sodium 
  • Sodium perborate
  • Whiteners 
  • Artificial colors (hair dye) 
  • Synthetic fragrances 
  • Boron 
  • Bleach 
  • Parabens 
  • Sodium perborate 
  • Petroleum distillate 
  • Alkaline compounds 

As long as you avoid these ingredients, your wastewater should be a safe water source for irrigation.

Greywater can be harmful to some plants, such as spinach and lettuce, but in most cases, it is harmless.  

If you’re concerned about safety, we recommend setting up your system so the water only filters to larger plants and shrubs, such as ornamental trees and perennials. These plants are tough and likely won’t be harmed by anything in the greywater.

This way, you’re still reducing water usage but aren’t risking your safety by using wastewater on edible plants, such as vegetables. 

How Does a Greywater System Work?

Greywater systems take wastewater and pipe it into a surge tank. Then, the system filters the water into an irrigation system, where it can water the landscape.

As a result, greywater systems reduce the need for treated water typically used for landscaping. 

Diagram of a DIY Greywater System
This DIY greywater system uses wood and gravel as a filtration medium. Courtesy of Climate Biz.

Some systems are complex and require significant plumbing and piping work. Still, homeowners can install simpler systems to reduce water usage and sewer costs. 

A laundry-to-landscape system captures the water from a washing machine and connects it to a valve that transfers it to the landscape.

This system doesn’t alter the plumbing, so you don’t need to get a permit. It’s also the most affordable way to implement greywater technology in your home. 


Advantages of Grey Water Systems

Now that grey water systems are efficient and sustainable, what are the benefits of having such a system at your home?

  • Reduced water consumption: A properly installed grey water system will greatly reduce your home’s water consumption. These systems can help you reduce water consumption by as much as 40 to 50%. By conserving water, you help lower your water company’s footprints.
  • Cost saving: Although installing a grey water system can be costly, the system will help you save money in terms of lower water bills. The savings will help you recoup the initial investment within a few years.
  • Enhanced sustainability: These systems increase water efficiency in all operations, making a home more sustainable. As already mentioned, water is a scarce resource, therefore, conserving it is an excellent way to enhance your home’s sustainability. 


Greywater systems are efficient, sustainable systems that reduce the amount of water and energy used to irrigate landscapes, which reduces the burden on the planet and wastewater treatment facilities.

They can also reduce water and sewer costs. 

In addition, greywater systems are safe for irrigation use as long as people use greywater-safe soaps and detergents. So start setting up yours today!

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