Laundry-to-Landscape Greywater System Rebate Requirements

• Use only a single domestic clothes washer in a residential single-family or duplex site only.
• You must adhere to state and local regulations, including Chapter 15 section 1503.1 and 1503.1.1 of the California Plumbing Code.
• No filters, no tanks, no potable water connection, and no pumps (except for the pump in the clothes washer itself) are allowed or needed for greywater L2L systems.
• The following features are ideal for this rebate:
  • The clothes washer is near an exterior wall or you have an accessible crawl space.
  • The landscape should be about the same elevation or downhill from the clothes washer.
  • Your landscape is within 50-75 feet of your clothes washer.
  • You plan to irrigate fruit trees, ornamental trees, shrubs, bushes, vines, or small groupings of plants.

• All greywater must be gravity-fed and distributed from the clothes washer to a pre-approved landscape area that is large enough to absorb the greywater.
• Mulch basins are required. A mulch basin is a trench dug around the outer edge of a plant’s drip line and back-filled with mulch. A plant’s “drip line” is an imaginary line drawn from the outside branches of a plant down to the soil.
• The landscape area with mulch basins must be sufficiently sized to prevent runoff and pooling of greywater.
• The greywater system may have one or more valve zones. Mulch basins within each zone must meet or exceed the required square footage provided.
• Mulch must be replenished every 3-5 years or when mulch in the basins has decomposed.

Greywater must: 

• Not be stored, not runoff into streets and waterways, and not pond or pool on the surface.
• Not be used to irrigate crops or come in contact with the edible parts of food crops that touch the soil.
• Be contained on the site where it is generated.
• Be distributed subsurface or released to an area covered by a minimum of two inches of soil, bark, rock, mulch, or appropriate permeable cover.
• Have an unobstructed exit route into the landscape (for example, if every valve is accidentally closed, the greywater is still able to reach the landscaping).
• Avoid shallow utilities (water, gas, electric) or septic systems by calling the Underground Service Alert at (800) 227-2600 or 811 before you dig.

• Greywater must be distributed at least:
  • 18 inches from the property line;
  • 2 feet from buildings;
  • 50 feet from any septic tank or leach field; and
  • 100 feet from wells, waterways, or other water sources.
• Greywater piping/tubing and the diverter (3-way) full-port ball valve shall be the same diameter as or larger than the clothes washer drain hose. Typically, 1-inch diameter
• The end of the main-line tubing shall be left fully open (allow a continuous unobstructed greywater route from the clothes washer to the landscape; never use a valve or plug on the distribution point furthest away from the clothes washer.)
• The greywater system shall:
  • Not include a potable water connection, filters, or a pump. (Note: The pump in a clothes washer is not considered part of the greywater system.) 
  • Not connect to overhead (spray) irrigation. The system cannot connect to a conventional irrigation system.
  • Be designed to prevent clogging of any emitters.
  • Be designed and installed to prevent contact with humans and pets.
  • Be labeled with, “Caution: Non-potable greywater. Do not drink”.
  • Include a diverter (3-way) full-port ball valve to allow the user to direct the flow of greywater between the greywater system and the sanitary sewer/septic system. Include an auto vent (or an in-line vent or an air-admittance valve).
• The diverter valve and auto vent assembly:
  • Must be installed at least 6 inches above the flood rim (typically the top) of the clothes washer.
  • Must be easily accessible and labeled. Labeling shall indicate which direction to turn the diverter valve’s handle to send greywater to either the landscape or the sanitary sewer. The diversion valve must be clearly labeled and easily accessible.
  • All wastewater derived from the below activities must be directed to the sanitary sewer. These activities include, but are not limited to:
    • Washing diapers or similarly soiled garments
    • Washing greasy or oily rags
    • Cleaning car parts
    • Disposal of waste solutions from photo labs
    • Other activities that contain hazardous chemicals.
• Any perforations in the building created during installation are properly sealed or patched.
• Greywater systems are not suitable for lawns, small or potted plants, raised beds, pH-sensitive plants, established never irrigated plants, very low water use plants, and edible gardens.
• Have a user manual posted in close proximity to the system (see Daily Acts Greywater Handout for a printable manual).

• Rebates are offered on a first-come, first-served basis, subject to availability of funds.
• Rebates cover the cost of equipment used for a greywater system only. This excludes tax, delivery, and labor.
• Be an active Petaluma water customer.
• Residential single-family or duplex sites only.
• Be the property owner, or have written consent from the owner.
• Submit a complete greywater pre-inspection questionnaire with the required photos.
• Have a working clothes washer machine onsite.
• Have a suitable irrigable landscape that is level or down-sloping from the location of the clothes washer.
• Only one rebate shall be redeemed per water account.
• This rebate is for Laundry to Landscape greywater systems only.
• The greywater system must be installed at the address provided on the application.
• The City of Petaluma reserves the right to request proof of installation and/or to inspect the property to verify that the system is installed, either before or after the rebate is paid.  Failure to allow an inspection within 30 days of the request may result in rebate denial or rebate recovery costs from the applicant.
• Be pre-approved prior to installing the system.
• Must install the greywater system and contact the Water Conservation Department within 120 days of pre-approval.
• Receipts must be legible and itemized to clearly show what has been purchased. If submitting an invoice from a contractor please ensure it includes the name and address of the contractor, the itemized dollar amount of qualifying purchase(s), item names, and zero balance due. Receipts will not be returned – Please make copies for your records.
• A mandatory self-monitoring report shall be submitted annually by the resident to assess compliance with the above system requirements. The City will send out a self-monitoring form yearly.