A purple sign noting the use of greywater in irrigation

Are you considering installing a greywater system in your home? You’re not alone—many homeowners are interested in using these systems to conserve water and reduce water bills.

But before you install a greywater system, you need to check your state’s laws to see if they are legal.

This article will discuss the legality of greywater systems in the U.S. It will list which states allow this technology and which have restrictions.

We’ll also preview how some states regulate these systems and provide tips on checking greywater regulations in your state.

So, let’s dive in!

Are Greywater Systems Legal?

Greywater systems are legal in the United States. First, however, you must be sure that your state allows these systems. If it does, check the specific regulations before installing one in your home.

Currently, some states have strict laws on greywater, while others offer a rebate.

Greywater Laws by State

Sustainable living is increasing in popularity. As a result, many homeowners are looking into greywater systems to reduce their water usage.

Currently, the USA has no standard greywater law that cuts across all the states.

What does this mean?

It means before installing one, it’s essential to check whether or not they are legal in your state.

Each state follows specific guidelines on the installation and use of greywater. Also, how an individual state defines greywater varies by several factors.

Let’s look at states with similar laws. We’ll begin by grouping states that lack formal regulations of greywater.

States Without Formal Greywater Laws

Here’s a table showing the states that lack formal greywater regulations:

States Without Clear Definition of GreywaterStates That Allow Wastewater Reclamation and Define Greywater As Wastewater
New HemisphereLowa
New JerseyLouisiana
New YorkMississippi
West VirginiaMissouri
North DakotaRhode Island
South Carolina

States That Allow the Reuse of Greywater

This table shows states that allow residents to reuse greywater:

States That Allow the Reuse of Greywater for Residential Irrigation OnlyStates That Permit Greywater Through a Tiered ApproachStates That Regulate the Reuse of Greywater Without a Tiered Approach
MaineNew MexicoMontana

WashingtonNorth Carolina

South Dakota






States With Greywater Tax Benefits and Financial Assistance

If you install a greywater system, you may be eligible for tax breaks or other financial incentives in some states.

For example:

  • In San Diego, California, you can get a rebate of between $150-$250 for residential cloth washer systems. In addition, you can get up to $1,000 for systems not following the cloth washer system.
  • In Santa Clara, California, homeowners can receive up to $400 to install a greywater system.
  • In Arizona, a greywater harvesting rebate can reimburse homeowners up to $1,000 for installing a harvesting system.

Check with your state’s tax authority to see any available benefits.

How Some States Regulate Greywater Systems

The use of greywater systems is regulated differently in each U.S. state.

Some states have very lax laws regarding greywater systems. Others have stringent laws.

It’s crucial to check the regulations in your state before installing a greywater system.

States such as Ohio have specific laws about what types of greywater can be used and how homeowners can use them.

In some states, such as California, greywater systems are legal and encouraged. Here, greywater can only be used for irrigation and must be treated before you can use it.

Furthermore, recent research shows that it’s possible to water your plants using recycled dehumidifier water.

A woman watering house plants from a small green watering can using water from a greywater system.
Dehumidifier water can safely be used to water house plants. Make sure not to use it for food plants, though. Trace contaminants could be present, which might harm your health if you eat them.

In other states, like Arizona, greywater systems are legal, but some restrictions exist. For example, Arizona residents can use greywater for irrigation and toilet flushing.

Still, in other states, like Texas, residents need a plumbing permit.

Homeowners in Texas may get the following:

  • Laundry-to-landscape system permits
  • Permits for gravity-flow systems that use less than 250 gallons a day

Note: you can learn more about residential greywater in Austin, Texas, on the Austin Water website.

Most states recommend separate plumping of greywater, which must be identified as non-drinkable.

For some states, sink waste and laundry water is labeled as black water. This water cannot be reused in greywater systems.

Here are some examples of state regulations:

Greywater Regulations in Alabama

In Alabama, the use of greywater systems is regulated by the state Department of Public Health. As a result, they are legal as long as users follow specific guidelines.

For instance, the law requires greywater operators to install filters and disinfect the water before reuse.

Greywater Regulations in Arizona

Exterior view of a Pacesetter Home Center green home

Arizona has very few regulations regarding greywater systems. 

You don’t need a permit to use greywater at your home if you live there. You can use greywater for household gardening (except for food plants) or landscaping. However, it’s best not to let the water run off your property.

Also, Arizona requires the flow of not more than 400 gallons (1,514.16 liters) of greywater per day.

Check the Arizona Department of Environmental Quality to learn more.

Greywater Regulations in California

California has a statewide greywater policy, which the California Building Standards Commission administers.

In California, greywater systems are regulated by the California Plumbing Code.

Greywater systems must be designed and installed by a licensed contractor.

In addition:

  • Greywater systems are legal as long as homeowners use the water outdoors.
  • The system must be designed and installed to prevent greywater from coming into contact with potable water.
  • The local building department must inspect the system.
  • Greywater systems should be able to direct the greywater back to the sewer line.
  • Homeowners cannot use greywater to irrigate food crops.

Greywater Regulations in Maine

The Maine government defines greywater as water from laundry, sinks and basins, tubs, and showers.

In Lobster state, greywater systems are legal as long as they follow certain guidelines.

For instance:

  • Homeowners should treat greywater first before it’s disposed of.
  • You need a permit to install a greywater system.
  • Laundry water or bathing water doesn’t count as greywater. These can transmit pathogens and should only be directed to the traditional sewer system.

Greywater Regulations in Ohio

The Columbus, OH skyline at dusk with the Scioto River in the foreground

The state of Ohio defines greywater as water from shower areas, laundry sinks, cloth washers, and lavatories.

It is defined as water that doesn’t contain food waste, fecal matter, or urine.

The state allows the use of greywater for irrigation purposes. However, it’s a requirement to inspect the soil before you do this.

In Ohio, there are three types of onsite non-potable greywater reuse, including:

  • Surface and subsurface landscaping – this category includes irrigation of lawns, landscape plants, and food crops.
  • Subsurface landscaping – this designation includes irrigation of landscape plants, lawns, and gardens.
  • Subsurface irrigation – irrigation of food crops only—except for crops with roots touching the greywater.

The United States EPA has published guidance on non-potable water reuse.

Greywater Regulations in New Mexico

In New Mexico, you don’t need a permit to install a private residential greywater system that adhere to the following conditions:

  • It has a discharge of less than 250 gallons (946.35 liters) per day
  • The greywater system’s storage tank is covered to eliminate habitat for mosquitoes and restrict access
  • It’s situated outside of a floodway
  • The greywater system is vertically separated at least five feet above the ground water table
  • All greywater piping systems have been labeled as non potable water conduits
  • The greywater does not run off property lines
  • The water is discharged in a way that minimizes the potential for contact with people or pets 
  • The greywater is not stored for more than 24 hours before being discharged

Greywater Regulations in Oregon

The State of Oregon defines greywater as water discharged from bathtubs and showers, kitchen sinks, bathroom sinks, and laundry machines. It doesn’t incorporate garbage waste (kitchen sinks with garbage), toilet discharge, or wastewater contaminated with soiled diapers.

If properly collected and handled, the state permits the usage of greywater for toilet and urinal flushing as well as irrigating some trees and plants.

It’s worth noting that you need a permit to reuse greywater in Oregon. Yous should obtain either of the following permits from DEQ:

  • Tier 1 general permit (2401)
  • Tier 2 general permit (2402)
  • Tier 3 individual permit

Tips on How To Check Your State’s Regulations

You can check with your local authority or do a quick search online to find out the specific laws in your state.

Here is a quick guide to help you get started:

Check With Your State Department of Water Resources

To determine whether or not greywater systems are legal in your state, the best place to start is by checking with your state’s department of water resources agency.

The department should be able to tell you the specific regulations in your state.

Contact Your State’s Environmental Agency or Department of Health

If you’re unsure whether greywater systems are legal in your state, the best way to find out is to contact its environmental agency or health department.

It will be able to provide you with information on any regulations in place.

In addition, they’ll tell you what the specific laws are in your area and whether or not you need a permit to install a greywater system.

In some states, they are legal, but there may be restrictions on how homeowners can use them—you’ll learn if you’re supposed to use your greywater for irrigation or other purposes.

Search Your State’s Code of Regulations

You may also need to search your state’s code of regulations online. You can usually find this information on the state’s environmental protection agency website.

Once you’ve found the relevant section of the code, you’ll need to read through it carefully to see the requirements for greywater systems.

Some states have precise requirements, while others are more general.

Locate the Greywater Action Website

Another good resource for finding out about greywater laws is the Greywater Action website. This website provides information on greywater regulations in the U.S.

You can search for your state to see the specific laws regarding greywater systems. The website also provides resources and information on installing and maintaining one.

Once you know what the laws are in your state, you can start planning your system.

First, be sure to check with your local building department to ensure that yours meets all requirements.


Greywater systems are legal in most states.

However, it’s essential to check your state and local regulations. Additionally, even if your state does allow them, you may still need to get a permit before installing one.

You can enjoy greywater tax benefits if you live in states like Arizona or California.

For instance, in Arizona, homeowners can get a reimbursement of up to $1,000 for the installation of a greywater harvesting system.

Overall, greywater systems are life-saver and worth considering if they are legal in your state.

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