Graywater Systems

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What is Graywater?

Graywater is untreated waste water that has not been contaminated by any toilet discharge, has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater includes waste water from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include waste water from toilets, kitchen sinks, dishwashers, or laundry water from soiled diapers, due to potential health issues.

Graywater Systems

Using graywater is an excellent way to recycle and conserve water, and can help you reduce potable water consumption. Your indoor water can be reused as graywater, providing a constant source of recycled water for irrigating landscape including fruit trees, but excluding vegetable gardens. Typical graywater systems are onsite wastewater systems that use untreated graywater for subsurface landscape irrigation through the use of mulch basins, disposal trenches or subsurface drip irrigation fields.

Basic graywater systems using wastewater from a single clothes washer in a one- or two-family dwelling may be installed without a permit provided certain requirements are met. Simple and complex systems that affect existing plumbing, electrical, mechanical or building systems require a permit, as well as any system that includes a potable water connection or the use of a pump.

Graywater Regulations

Graywater systems are regulated by the City of Encinitas in accordance with Chapter 15 of the California Plumbing Code (CPC). Additionally, the California Regional Water Quality Control Board - San Diego Region (Regional Board) regulates all discharges of wastewater to land. The Regional Board has issued a waiver (Waiver No. 1 of Order No. R9-2014-0041) that allows discharge of graywater provided a Notice of Intent (NOI) (Attachment A) to discharge is filed with the Regional Board (SanDiego@waterboards.ca.gov).

Graywater Systems in New Single-Family Homes

Effective September 20, 2015, all new single-family homes must be pre-plumbed with graywater plumbing to all graywater eligible discharge sources and with a stub-out convenient for connection to the landscape irrigation system. Refer to Ordinance 2016-10.

More Graywater Information

The following documents provide information on submittal requirements for systems that require permits as well as standards and requirements for systems that do not require permits:

Existing Residential Graywater Irrigation Systems

New Residential Graywater Irrigation Systems

Fee Waiver

On September 23, 2015, the City Council adopted Resolution 2015-57 waiving fees for installation of graywater systems in existing one- and two-family homes. Systems that require alteration of mechanical systems or require building modification would be subject to fees for those portions of the systems.

Residential Graywater Irrigation Systems FAQ

This section provides more information and guidance on the installation and regulation of graywater systems in Encinitas. Here, you will find definitions, approval requirements, submittal requirements, plan review processes, associated fees, and inspection guidelines.

Have more questions? Please email climateaction@encinitasca.gov.

A. General Information

What is graywater? Graywater is untreated wastewater that has not been contaminated by toilet discharge or unhealthy bodily wastes. It includes wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but excludes water from toilets, kitchen sinks, dishwashers, and laundry water from soiled diapers.
Is graywater the same as recycled water? No, graywater is not the same as recycled water. Recycled water is highly treated wastewater from a treatment facility, used widely throughout Encinitas in landscaped areas of City parks, street parkways, and many homeowners' association landscaped areas.
How can using graywater benefit me? Using graywater can help you recycle and conserve water, reducing potable water consumption. It provides a constant source of recycled water for irrigating landscapes, including fruit trees but excluding vegetable gardens.
How much graywater does a standard home generate? A standard home generates about 160 gallons of graywater per day, or nearly 60,000 gallons per year. A family of four could reuse 22,000 gallons per year by installing a washing machine graywater system.
What are the financial benefits of installing a graywater system? Installing a graywater system can lead to significant financial savings by reducing your potable water consumption, which lowers your water bills. Additionally, graywater systems can increase the value of your property by making it more environmentally sustainable. The City of Encinitas also offers fee waivers for graywater systems under the Energy Efficiency Permit Fee Waiver Program, reducing initial installation costs.
Is graywater regulated? Yes, the design, installation, and maintenance of graywater systems are regulated to protect public and environmental health. Regulations ensure these systems operate in all weather conditions, prevent groundwater and surface water contamination, and minimize human and animal contact with effluent.
What are the differences between blackwater and graywater? Blackwater contains fecal matter and urine from toilets, while graywater is less contaminated wastewater from non-toilet sources like showers and washing machines.
Why is the water from the kitchen sink and dishwasher considered blackwater instead of graywater? Kitchen sink and dishwasher water are considered blackwater due to high levels of food particles, grease, and organic materials, which increase contamination risk.
What are the differences between a rainwater system and a graywater system? A rainwater system collects and stores rainwater for various uses, while a graywater system recycles household wastewater for immediate landscape irrigation.
What are the basics of graywater systems? Graywater systems should not store graywater for more than 24 hours, minimize contact with graywater, ensure graywater infiltrates into the ground, and avoid pooling or runoff. Simple systems are encouraged for longevity, ease of maintenance, and lower cost. A diverter valve must be installed, per CPC 1503.2.2, and in a readily accessible location, for easy switching between the graywater system and the sewer system. The exception applies to a clothes washer system (1503.1.1).
What products should I use with a graywater system? Use plant-friendly products in washing machines, sinks, showers, and tubs that provide graywater to the system. Avoid products containing boron or salts harmful to plants.
What are some reasons why I cannot or should not install a graywater system? There are several factors that might prevent or discourage the installation of a graywater system. The soil on the property may not support a graywater system, depending on its ability to percolate water effectively. Sandy soil is better suited for draining and filtering graywater compared to clay soil, which may lead to inadequate filtration. Additionally, the size of the yard could be insufficient to allow for proper discharge, especially when considering setbacks, biobasins, or hardscapes. Homes with basements may also face limitations, as basements can restrict available space for irrigation due to required setbacks.
Does the city have a consultant list for designing graywater systems? The City cannot recommend consultants. We recommend running a quick google keyword search or use the County of San Diego’s list of approved consultants. You can also try the local S.D. chapter of the American Society of Mechanical Engineers (https://sections.asme.org).

B. Graywater Requirements and Permitting

What are the requirements for graywater systems in new single-family homes in Encinitas? Effective September 20, 2015, all new single-family homes in Encinitas must be pre-plumbed with graywater plumbing to all graywater eligible discharge sources and include a stub-out convenient for connection to the landscape irrigation system. See Ordinance 2016-10 (EMC 23.12.110.D) and New Residential Graywater Irrigation Systems Guidelines.
What is the difference between a pre-plumbed graywater system and a complete graywater system in new construction? A pre-plumbed system includes all underground plumbing installed during construction and stubbed out for future graywater system connections, whereas a complete graywater system includes all necessary plumbing routed to the exterior with an irrigation system installed and operational.
What if I want to go above the minimum requirement and install a complete graywater system when building a new home? Installing a complete graywater system in your new home involves incorporating all necessary components such as tanks, pumps, filters, and distribution networks to recycle and irrigate with graywater immediately upon occupancy. This exceeds the minimum pre-plumbing requirement and offers immediate environmental and water conservation benefits. Additional fees may apply (see Fees section).
What graywater systems can I install without a permit? Systems that utilize only a single domestic clothes washing machine in existing one- or two-family dwellings do not require a permit. These systems may not include a potable water connection or the use of a pump, must not affect other plumbing, electrical, mechanical, or building components, and must comply with graywater system requirements as per Chapter 15 of the California Plumbing Code.
What are my options if I have an existing home and I am interested in adding a graywater system? If you have an existing home in Encinitas and are interested in adding a graywater system, you can explore options depending on the complexity of the system. Simple systems using wastewater from a single clothes washer or outdoor shower may not require a permit, while more complex systems or those affecting existing plumbing systems will require a permit from the City of Encinitas. Please review the Existing Residential Graywater Irrigation Systems Guidance Document for more information.
Do ADUs have any graywater requirements? An accessory dwelling unit (ADU) is not classified as a single-family dwelling under the California Building Code. Therefore, ADUs are not required to have a graywater system. However, homeowners can choose to install a graywater system in an ADU if they wish to do so. Any installation must still comply with the policies outlined in the New Residential Graywater Irrigation Systems Guidance Document.
What are the graywater requirements in Encinitas for multifamily and nonresidential new construction? There are no mandatory requirements for graywater plumbing in multifamily and nonresidential new construction in Encinitas. If a system is voluntarily added, it must meet the requirements outlined in Chapter 15 of the California Plumbing Code and must be included in the building permit plans for approval.
Are there exemptions for graywater systems? Yes, certain graywater systems are exempt from permitting requirements. Systems that use only a single domestic clothes washing machine in existing one- or two-family dwellings are exempt, provided they do not include a potable water connection or a pump and do not affect other building systems. Additionally, if the property soil is deemed unsuitable for graywater use as determined by a percolation test, an exemption may be granted if a letter from a certified soils engineer is provided. It's important to verify with the City of Encinitas for any specific exemptions applicable to your project.
What is the minimum requirement for a pre-plumbed graywater system in new construction? At a minimum, the plans should include a plumbing isometric and plot plan showing property lines, structures, setbacks, paved areas, drainage, retaining walls, water lines, bedrooms, plumbing fixtures, graywater system, water connections, meters, and sewer lines. Additional notes on the complete system are also required for information only.
What are the plan requirements for a complete graywater system in new construction? In addition to the requirements for a pre-plumbed system, plan requirements for a complete graywater system typically include detailed diagrams showing the layout of tanks, distribution pipes, filters, and any associated pumps. These plans must comply with local building codes and plumbing regulations to ensure safe and effective operation.
Where can I find a list of all required submittal items for a pre-plumbed and/or complete graywater system? You can find this in the New Residential Graywater Irrigation Systems Guidance Document.
What are isometric drawings and why are they important? Isometric drawings are three-dimensional representations of objects, showing the layout of pipes and components in graywater systems. They are important because they provide a clear visual of how the system components are connected, ensuring accurate installation and compliance with regulations.
What should be included in isometric drawings for graywater systems? Isometric drawings for graywater systems should include detailed illustrations of all plumbing components, such as pipes, fittings, and valves. They should show the flow direction, pipe sizes, and connections to the graywater sources and distribution areas. These drawings help in understanding the system layout and identifying potential issues during installation. Below is an example:
Does every new construction project require a permitted graywater system, or is it sufficient to show a stub-out on the plans? Every new construction project requires a permitted graywater system that can be included as part of the building permit. Showing only a stub-out on the plans is not sufficient. Additionally, every graywater system, whether pre-plumbed or complete, must include an isometric drawing in the plans. Depending on the complexity of the system, a separate permit may be required at the discretion of the building official. See the New Residential Graywater Irrigation Systems Guidelines for more details.
Is a simple site plan showing the location of a graywater stub-out enough? No, a simple site plan alone is not sufficient. In addition to the site plan, you also need to include an isometric plan of the graywater system. The isometric plan provides detailed drawings of the plumbing layout, ensuring clarity and compliance with the requirements. See the New Residential Graywater Irrigation Systems Guidelines for more details.
Do I need to apply for a permit for a new construction graywater system, or can I just add a stub-out? Installing a stub-out or pre-plumbed system for graywater in new construction does require a permit. This can typically be included as part of the building permit process, unless the graywater system is complex or involves additional components like electrical pumps, sump pumps, lift stations, or electrical panel upgrades. In such cases, a separate but concurrent permit may be necessary. This ensures compliance with all necessary regulations and standards related to graywater systems.
What graywater requirements apply if my addition or alteration project triggers the City’s definition of “new construction”? If the addition or alteration is such that it would trigger the new construction definition, then the pre-plumbed graywater system requirement (EMC 23.12.110.D) would only apply to the addition or altered portion.

C. Plan Review

How does the City review graywater system plans? The City reviews plans for compliance with the California Plumbing Code. Structural review may be needed for above-ground tanks. If existing structures or systems are affected, additional reviews are required.
What is the process for water district review? San Dieguito Water District reviews applications within its service area as part of the City’s process. For projects in the Olivenhain Municipal Water District (OMWD) area, separate submission, deposits, and approval are required. Additional reviews and fees apply for systems with cross-connections to potable water.
What additional paperwork is required to ensure the graywater system is in compliance? To ensure the graywater system complies with regulations in Encinitas, you'll need to file a Notice of Intent (NOI) (Attachment A) with the California Regional Water Quality Control Board - San Diego Region (Regional Board) if your system requires a permit. This includes providing details about the system's location, ownership, operation, and compliance with applicable waivers. Applicants can send their NOI by email to SanDiego@waterboards.ca.gov.

D. Fees

What fees are associated with graywater system permits? Contact the Building Department for permit fees. For water district fees and requirements, contact the respective water district serving your property.
Are there any fee waivers for graywater systems? Yes, the City Council approved the inclusion of graywater systems in the Energy Efficiency Permit Fee Waiver Program. City review fees for typical systems are waived. Systems requiring mechanical alterations or building modifications would be subject to fees for those portions.

E. Inspections

How many inspections are required for graywater systems in new construction? A minimum of three plumbing inspections are required: underground, rough, and final.
How many inspections are needed for graywater systems in existing buildings? A minimum of two plumbing inspections are required: rough and final.
Who should I reach out to if I have questions about the graywater requirements in Encinitas? For more information on graywater systems and submittal requirements, contact the Development Services Department at planning@encinitasca.gov or (760) 633-2710. Other helpful resources include:
1. California Urban Water Conservation Council
2. San Diego Sustainable Living Institute
3. San Diego County Water Authority
4. New Residential Graywater Irrigation Systems Guidance Document
5. Existing Residential Graywater Irrigation Systems Guidance Document

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Graywater Systems

What is Graywater?

Graywater Systems

Graywater Regulations

Graywater Systems in New Single-Family Homes

More Graywater Information

Fee Waiver

Residential Graywater Irrigation Systems FAQ