Greywater Laws in California:
CPC Chapter 15, L2L No-Permit Rules & Rebates

California's Two-Track Greywater System

California distinguishes between two categories of residential greywater system, and the rules differ significantly between them. Understanding which category your planned system falls into is the most important first step.

Track 1 — Laundry-to-Landscape (L2L), No Permit: This covers any system that redirects washing machine water to the landscape without altering the home's existing plumbing. The water is captured from the machine's drain hose before it reaches the standpipe, then routed outside via a three-way diverter valve and poly tubing. This system is specifically exempt from construction permits under CPC Chapter 15 for single- and two-unit residential buildings.

Track 2 — All Other Greywater Systems, Permit Required: Any system that collects water from showers, bathtubs, bathroom sinks, or that requires cutting into the home's drain or supply plumbing requires a construction permit from the local building department. These permits are processed by local jurisdictions (cities and counties) under the California Plumbing Code, and approval criteria vary. San Francisco, Los Angeles, and San Diego all have streamlined review processes for residential greywater permits.

The 13 No-Permit Requirements for L2L Systems

To qualify for the no-permit exemption under CPC Chapter 15, your laundry-to-landscape system must meet all 13 of the following conditions:

1. The system is installed in a one- or two-unit residential building (not apartments, condos over 2 units, or commercial).
2. The system does not alter the existing plumbing — you access the water from the washing machine's drain hose, not by cutting a drain line.
3. The system operates by gravity or by the washing machine's own pump — no additional pumps are added.
4. The greywater is from the clothes washer only — no other sources (this is what makes it L2L specifically).
5. Greywater is used within 24 hours — no storage tanks holding water overnight.
6. Greywater is distributed subsurface or under mulch — not sprayed or applied on bare soil.
7. Greywater does not come into contact with the edible portion of food crops.
8. Greywater does not run off the property or reach a storm drain, street, or neighboring property.
9. Greywater does not pond or pool on the surface.
10. The system includes a manual or automatic diverter that can redirect water to the sewer/septic at any time.
11. All components are accessible for inspection and maintenance.
12. Greywater from diapers or similarly soiled garments is excluded — use the sewer for those loads.
13. An operation and maintenance manual is provided and stays with the building. When the property is sold, new owners must be informed the system exists.

Step-by-Step: Installing a Legal L2L System in California

Here's the complete process for a California-compliant laundry-to-landscape installation:

Step 1: Plan Your Irrigation Zones

Walk your property and identify 3–8 trees, shrubs, or landscape areas that could benefit from regular irrigation. Each zone will become a mulch basin. Consider proximity to the washer's location — the system works by gravity or machine pump, so zones near the house (within 50–100 feet) work best without pumping.

Step 2: Buy Materials

Core materials for a basic 3-zone L2L system in California:

• 3-way diverter valve (¾" or 1" depending on machine) — $30–$60
• 1-inch polyethylene tubing, 50–100 feet — $30–$50
• 1-inch barbed tee fittings — 1 per zone, ~$5 each
• 1-inch end caps — 1 per zone, ~$3 each
• Pipe clamps — $10
• Wood chip mulch, 1–2 yards — free from arborists or ~$40 from a supplier
• Purple pipe tape for labeling — $5
• Total: $100–$175 for most installations

Step 3: Install the Diverter Valve

Disconnect the washing machine's drain hose from the standpipe. Connect it to the inlet of your three-way diverter valve. Connect one outlet back to the standpipe (this is your sewer overflow) and one outlet to your new polyethylene tubing leading outside. Label the valve "GREYWATER — NON-POTABLE" and mark which position routes to sewer vs. landscape.

Step 4: Route Tubing to Landscape

Run 1-inch poly tubing from the valve through a wall penetration (a standard hole saw makes a clean exit through stucco or wood siding) or under a door threshold, then underground or on the surface to your planting zones. California code requires all outlets to be under mulch — you can run the tubing on the surface between mulch basins as long as the discharge points themselves are covered.

Step 5: Build Mulch Basins

At each irrigation zone, excavate a shallow basin 4–8 inches deep and sized to absorb your expected daily laundry volume. Fill with wood chip mulch to within 1–2 inches of grade, bury your tubing outlet in the mulch, and add a final mulch cap. For California sizing guidance by soil type, use our sizing calculator.

California Greywater Rebate Programs

Several water agencies in California offer rebates for residential greywater installations. Programs vary by district and can change — verify directly with your water provider:

To find your specific water agency's current rebate: look for "greywater rebate" + your city or water district name. Most rebate applications are simple — submit before installation or immediately after, with a photo and a copy of your materials receipt.

Permitted Systems: Shower, Bath & Sink Greywater

If you want to capture shower, bathtub, or sink water in California, you'll need a construction permit from your local building department. The permit covers the plumbing work required to access these drain sources, which involves cutting into your home's drain system — that's the work requiring oversight, not the greywater reuse itself.

The process varies by city, but generally:

• Submit a permit application to the local building or plumbing department
• Include a simple diagram showing water sources, pipe routing, storage (if any), and landscape discharge points
• Permit fee: typically $150–$400 depending on complexity and jurisdiction
• Work must be done by a licensed plumber or by the homeowner as owner-builder (rules vary by city)
• Inspection required before walls are closed

San Francisco's SFPUC has a particularly clear permitting guide for residential greywater systems — if you're in SF, start at sfpuc.org/greywater for the most current process.

Local Variations Worth Knowing

While the CPC establishes the baseline, several counties and cities have adopted specific local amendments or programs:

• Livermore: Requires city approval (simple notification, not a full permit) for L2L systems in buildings with more than two units, or if the system includes a pump.
• Sonoma County: Has a dedicated greywater permit checklist and actively processes residential permits. They also allow simple "laundry divert" systems that redirect the hose outside as a no-permit bucket system.
• Sacramento area: No additional city requirements beyond CPC — the standard 13-point L2L exemption applies in most Sacramento jurisdictions.
• Southern California coastal districts: Many water districts are actively promoting greywater to reduce potable water demand and have rebate programs. Contact your retailer water agency (the one that bills you) for local programs.

Frequently Asked Questions — California Greywater

• My water bill is already low due to drought-rate rebates. Is greywater still worth it in California?+

  Yes — California's tiered water pricing means each additional unit of water you use above a baseline tier is more expensive than the last. By using greywater for landscape irrigation, you reduce your metered water use, keeping you in lower tiers. For a household in Tier 2 or 3 pricing (common in EBMUD, LADWP, and SDCWA service areas), displacing 1,500 gallons per month with laundry water saves $15–$35 per month at current tiered rates — often more than the simple unit price suggests.

• Can I use greywater during California water restrictions?+

  This varies by water agency and restriction stage. Greywater — especially laundry water — is generally exempt from outdoor watering restrictions in most California jurisdictions because it's water you've already paid for and used, not an additional draw from the supply system. LADWP, SFPUC, and East Bay MUD all explicitly exempt compliant greywater systems from watering restriction days. Verify with your specific water provider during declared restrictions, as Stage 4 emergency measures can vary.

• Can renters in California install an L2L greywater system?+

  A properly installed L2L system makes no permanent modifications to the property — you're connecting a removable hose to a diverter valve and running removable tubing outside. When you move, the system comes with you (the tubing can be pulled up, the hole through the wall or under the door patched). Technically, you should notify your landlord before drilling any holes in exterior walls, but many tenants run the tubing under a laundry room door threshold without any drilling at all. Get landlord permission in writing if possible — it protects both parties.

• What if I'm in a shared laundry situation (apartment with common laundry room)?+

  The CPC no-permit exemption applies to 1–2 unit residential buildings only. A shared laundry room in an apartment complex is a commercial installation that does not qualify for the residential L2L exemption. Any greywater system in a multifamily building requires a construction permit and must meet the full Chapter 15 standards, which include a treatment component for larger volumes. Building owners interested in multifamily greywater should consult with a licensed plumbing engineer and contact the local building department.