How a Greywater System Can Affect Your Budget

By Erica Corder

Water conservation is increasingly important under the strain of a growing population. But creative conservation solutions don’t have to be hard. One option is as simple as reusing water that would otherwise go down the drain after a single use—saving money, conserving water and reducing dependency on utilities in the process.

Greywater is the wastewater produced during daily activities like washing your hands, showering, using a dehumidifier and washing laundry. Typically, greywater systems designed to reuse this wastewater divert it to landscapes, lawns and gardens, instead of the sewer.

Greywater does not include wastewater from toilets, urinals, dishwashers or kitchen sinks. Often called blackwater, untreated water from these sources can be harmful to human health and the environment. Greywater, on the other hand, is safe for irrigation if reused within 24 hours of first use.

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Rather than essentially throwing away perfectly reusable water, building owners and managers can install a greywater system for cost savings and environmental benefits, and insulate themselves from potential water shortages. Depending on the project budget, there are many affordable greywater system options that pay for themselves in the long run.

Planning for a Greywater System in Your Budget

Ultimately, the greywater system needed depends on the end use of the water. While some may opt for a system that diverts greywater to toilets, commercial and industrial business owners will likely opt for greywater for irrigation, which might make the most sense for commercial operations.

Installing a greywater system involves costs associated with piping, valves, irrigation tubing, tanks, plumbing components, permit and inspection fees, and installation. These can all vary by local economy, state regulations and the complexity of the system being installed.

The simplest systems—greywater systems from laundry to lawn—cost as little as $100 to self-install. For more complex systems, full installation costs range anywhere from $800 to $4,000. According to Greywater Action, the highest end system for residential buildings—an automated pumped system for drip irrigation—ranges from $5,000 to $20,000.

However, the one-time installation cost and future maintenance costs of a system should be compared against the water rates of your building and the energy costs of pumping your water back to your locality’s wastewater treatment plants. Considering that greywater makes up the majority of water use in the average home, the reuse of that water could save tens of thousands of gallons of water while reducing the burden on your sewer system.

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Generally, a greywater system over time is better for the bottom line—and the environment. One bonus perk? Greywater systems can even help save on HVAC costs: By reusing nutrient-rich greywater as irrigation, you can water plants, which help absorb heat from the sun, cooling the area surrounding the building. Further, if the water irrigates nearby trees, buildings can enjoy even lower temperatures in the shade of the trees, decreasing air conditioning costs significantly.

Challenges of Implementing Greywater Systems

Before installing a greywater system, the first potential challenge may be your local regulations. Though your state may not have restrictions on greywater system, local rules might be more restrictive and supersede state regulations.

If greywater systems are permitted, however, the next challenge may be the design of an existing building. Retrofitting a greywater system is more costly than incorporating a system into new construction. This is especially true at a commercial level, since existing buildings might not already separate greywater from the blackwater of toilets and urinals. Having to retroactively separate greywater requires additional plumbing.

It will also likely require construction of a decentralized system. If your wastewater typically flows to a centralized wastewater treatment system, as is typically the case in more urban and densely populated areas, you will likely need to implement a hybrid decentralized and centralized system. This dual system deposits blackwater to centralized sewage systems and greywater to your decentralized system, where it can be reused locally and reduce water bills and the burden on centralized systems.

Some systems can actually treat both types of water and purify it for specific reuse, such as flushing toilets. This route is still cost-effective since it reduces dependence on local water supplies by over 75 percent and also limits the associated costs of pumping—but it does require significant upkeep due to the hazards of recycling blackwater.

Despite the potential challenges, greywater systems can pay for themselves in time. The more greywater incorporated in a building, the more quickly the system will begin to return the investment of installation and maintenance. For example, in a system designed for a UCLA Football Performance Center, up to 72 percent of the building’s water requirements were fulfilled by recycled greywater.

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With water shortages on the rise—60 countries are expected to see increases of shortages by 2050—implementation of a greywater system is a strategic move for the health of the globe and your wallet.



Erica Corder is a writer, reporter and multimedia producer based in Los Angeles, California. She particularly (but not exclusively) enjoys writing about engineering, technology and sustainability — and how those innovations impact humans and the planet alike.