Graywater Program

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Central Coast Graywater Alliance

What Is Graywater?

Graywater is waste water from laundry machines, bathroom sinks, showers, and bathtubs. California law does not allow graywater use from kitchen sinks or dishwashers. In January 2010, the California Building Standards Commission adopted Title 24, Part 5, Chapter 16A into the California Plumbing Code. The new graywater code applies to residential buildings only. The new graywater code facilitates water conservation, relieves stress on private septic systems, makes legal compliance easily achievable, and provides guidelines for avoiding potentially unhealthful conditions.

A typical California household produces more than 10,000 gallons of graywater between May and October. Although some municipalities recycle treated graywater to irrigate agricultural crops, most graywater is sent to a wastewater treatment plant which discharges the treated water to a local waterway or the ocean. Irrigating landscapes with graywater during the summer dry months is a sustainable solution for homes that do not have access to treated recycled water. Graywater irrigation conserves our precious water resources, conserves energy needed to pump and treat water, and saves money on your water bill!

Guidelines for Irrigating with Graywater
The CA graywater code allows residential graywater landscape irrigation from washing machines without a construction permit if the system meets all performance guidelines in the code. Learn how to create a functional graywater irrigation system that conserves water and protects the environment.

Obtaining a Graywater Construction Permit for Simple and Complex Systems
The CA graywater code requires a construction permit for any alteration to your home’s drain/vent plumbing for showers, bathtubs, and bathroom sinks. This section includes contact information for planning departments in the Monterey Bay area and what to expect from the permit process.

Request a Professional Graywater Consultation from a Member of the Central Coast Graywater Alliance
Members of the Central Coast Graywater Alliance can evaluate your home’s potential for graywater reuse and guide you through the permitting process.

2011 Graywater Workshops
View a list of current graywater training and workshop opportunities in the Monterey Bay Area.

Technical Resources about Graywater Systems
Greywater Action
Oasis Design: Offer outstanding how-to resources for graywater installers.

Guidelines for Irrigating with Graywater

■ Designing and installing your graywater system to meet performance standards is good for the environment, and it is the law! Under Title 24, Part 5, Chapter 16A , all graywater irrigation systems must comply with the following guidelines to protect the environment and avoid system failure:

■ Any graywater system that includes a connection to a potable or municipal water supply must have an approved, backflow prevention device. Laundry to landscape graywater irrigation systems that are exempt from permitting must have no connection to the potable water supply or an external pump.

■ The graywater system design must include an accessible, clearly labeled, three-way valve that diverts the graywater back to the building sewer. Graywater should be diverted to the building sewer during the rainy season between November and April.

■ The graywater must not leave the property where it came from or come within 100 feet of any creek, wetland, or waterway.

■ The groundwater table must be lower than 3 feet from the lowest graywater irrigation or disposal point.

■ Each release point of the graywater irrigation system must be covered with at least 2¨of mulch, rock, soil, or a soil shield. Sprinkler irrigation and ponding of graywater are not allowed!

■ Water used to wash diapers or other infectious garments must be diverted to the building sewer.

■ Graywater may not contain hazardous chemicals.

■ Graywater may not be used to irrigate root crops or other edible crops that touch the soil.

■ An operations and maintenance manual for the graywater system must be provided by the installer and must be transferred to the new tenant or owner for the life of the graywater system.

■ Graywater irrigation systems must be located a minimum horizontal distance away from the following landscape features:

Landscape Feature

Minimum Horizontal Distance from Graywater Irrigation System

Building structures

2 feet (610 mm)

Property line adjoining private property

1.5 feet (458 mm)

Water supply wells

100 (30,480 mm)

Streams Rivers,,Lakes, Wetlands, and High Tide line of Ocean

100 ft (30,480 mm)

Sewage pits or cesspools

5 (1,524 mm)

Sewage disposal field

4 (1,219 mm)

Septic tank

5 (1,524 mm)

On­site domestic water service line

0 (0 mm)

Pressurized public water main

10 (3,048 mm)

For detailed information regarding required setbacks for graywater tanks, graywater irrigation fields, and graywater disposal fields, see Table 16A-1 of Title 24, Part 5, Chapter 16A of the California Plumbing Code.

Obtaining a Graywater Construction Permit for Simple and Complex Systems

Simple and Complex Graywater Systems
Simple systems produce less than 250 gallons a day.
Complex systems produce more than 250 gallons a day.

Whereas laundry systems can utilize the internal pump to send graywater a short distance uphill, most simple and complex graywater systems from bathroom sinks, showers, and tubs rely on gravity to send water through a branched drain irrigation system. The graywater exits the branched drain irrigation piping into a covered mulch basin, and the biology of the soil is the treatment system that digests organic debris, soap, and any potential pathogens. Graywater to drip irrigation is possible, but requires pumping, filtration, and backflow prevention, all of which increase overall system cost and maintenance.

Steps to successfully obtaining a graywater construction permit

Step 1:

Seek professional assistance for designing your graywater system from a member of the Central Coast Graywater Alliance.

Step 2:

MONTEREY COUNTY RESIDENTS:
Unincorporated residents and City properties containing wells and/or septic systems:
Contact Monterey County Health Bureau, Environmental Health Review Service to obtain a permit for your graywater system.

City residents that do not contain a well or septic system:
Contact your local City Building Department to obtain a permit for your graywater system using the template graywater permit (PDF download).

SANTA CRUZ COUNTY RESIDENTS:
All unincorporated County AND City of Santa Cruz residents must begin the graywater permit process through Santa Cruz County Environmental Health Services.

Building Permit Application Requirements for Residential Graywater Irrigation Systems (PDF download)

All City residents must apply to their local City Building Department to obtain a graywater construction permit.

Step 3:

If your graywater system requires a pump, tank storage, or a connection to the potable water supply, contact your water supply agency for information on backflow prevention requirements.

What to Expect from a Professional Graywater Consultation & Installation

In order to avoid maintenance and environmental health issues, simple and complex graywater systems should be designed carefully by an experienced professional.

The collection plumbing inside or underneath the house should be performed by a licensed plumber who is familiar with the installation of 3-way valves and conserving the height of fall. If your graywater source is from a bathroom sink or shower/tub, you or your installer are legally required to apply for a construction permit so that the system can be inspected to assure code compliance.

The graywater disposal or irrigation system outside the house should be designed and installed by a licensed landscape professional or environmental engineer. The irrigation system should be designed to ensure that the estimated daily flow from your graywater source(s) match your soil’s infiltration capacity and the irrigation needs of your existing or planned landscape. Irrigation system installation will require digging narrow trenches, mulch basins, and careful pipe installation. Upon the completion and inspection of the graywater installation, the installer should provide you with a map that locates all system components and an operations and maintenance manual. If you are uncomfortable maintaining your graywater system, you should set up a maintenance contract with your installer to ensure optimum system performance. The key to success of your graywater system is a good design and active participation by the user(s) to follow the guidelines in the maintenance manual! All members of the Central Coast Graywater Alliance are plumbing, landscaping, and/or environmental engineering professionals who are committed to creating code-compliant graywater systems.

Central Coast Graywater Alliance Members

Graywater Alliance Member
Contact Information
Graywater Collection Plumbing
Graywater Irrigation Design, Installation & Maintenance
Engineered Graywater System Design
(831) 818-3184
  
X
  
(831) 471-9100
  
X
  
(831) 688-7764
X
    
(831) 425-3514
  
X
  
Monterey Graywater Group
(831) 402-8229
  
X
  
Handy Dan Construction and Greenwise Landscaping
(831)-643-9911
X
X
  
George Allen Plumbing
(831) 438-1335
X
    
(831) 476-6800
  
X
  
(831) 459-0656
  
X
  
Aqua Green
Landscape Irrigation
(831) 251-7362
  
X
  
(831) 425-2608
  
X
X
(831) 659-3820
    
X
(831) 426-9054
    
X
(831) 430-9116
    
X
Eco Engineering Inc.
831-239-3446
  
X
  

2011 Graywater Workshops

Saturday, May 14, 9am-5pm
Laundry to Landscape Graywater Irrigation hands-on installation class
Cost: $30
319 La Fonda Ave., Santa Cruz
Register at Santa Cruz Adult School

Saturday, May 21, 9am-5pm
Laundry to Landscape Graywater Irrigation hands-on installation class
Cost $30
700 Pacific Ave., Santa Cruz (Monterey Peninsula Unified School District Office)
Register at Monterey Adult School

The Green Gardener Certification Program has received an American Recovery and Reinvestment Act grant to provide graywater system design, installation, and maintenance training to landscaping and plumbing professionals in Monterey and Santa Cruz Counties from May-July, 2010. The Green Gardener Graywater Training Program is a partnership between the Monterey and Santa Cruz County Workforce Investment Boards, Hartnell and Cabrillo College, the Watsonville and Salinas Adult Schools, and Ecology Action. Underemployed or dislocated workers in the landscaping and plumbing industries will receive priority enrollment.

For more information, call Sherry Lee Bryan of Ecology Action, (831) 426-5925 x114.

Program Contact

Sherry Lee Bryan

Ecology Action
Phone: 831.426.5925 ext. 114
Fax: 831.425.1404
Email

 

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