Greywater Irrigation

With California’s on-going drought, finding alternative water sources is axiomatic. Purposefully re-using water that has already been purchased not only seems like a good idea, it seems like it would be required. Our team here at Bay Maples has become the South Bay’s leader in greywater systems; both for residential and commercial use.  And, we install a wide range of systems allowing almost anyone to get their greywater out into their garden.

Laundry to Landscape (L2L)

We can install an L2L system, including the irrigation to existing plants and trees, in one day. If you want to use your laundry water but don’t have an existing garden, we can help you design and install the optimal garden for an L2L system.

FAQ: L2L systems typically cost $1,200-2,500*

Pump and Filter Kits

We specialize in installing pump and filter kits for greywater irrigation and we’re an authorized installer of Grey-Flow products, the leading Australian greywater merchandize provider. Filter and pump kits are brought in when we are capturing water from showers and bathroom sinks. Because these systems have a pump, water can be sent to the edges of your property. Also, because of the filtering, drip line irrigation can be employed using the water efficiently and effectively. Depending on the size of your household, a great deal of water can be produced each day. Using State-of- the-Art greywater technology, our professionals can direct that water to your lawn and garden in a way that mirrors traditional drip irrigation.

The systems we install allow the user full control to direct the water either to the landscape or to the sewer. So, if you are using a product that might be harmful to your garden, merely flipping a switch changes the configuration and sends water to the sewer.

FAQ: Pumped Systems typically cost $7,000-20,000*

Beyond the Ordinary

Our specialists are experienced in integrating greywater systems with other traditional and alternative water sources. Many household generate a large amount of greywater; and yet, it still may not be enough for all of their irrigation needs. Incorporating rain water with greywater is a big step towards ending the need for additional municipal water. That being said, sometimes you need municipal water to supplement your greywater, like when you go on vacation. Configuring a system that allows you the flexibility to maintain the garden you want while minimizing your “water footprint” is our specialty.

“Every green natural place we save saves a fragment of our sanity and gives us a little more hope that we have a future”

― Wallace Stegner

Greywater FAQ’s

Frequently Asked Questions

Can I water my lawn with greywater?

By traditional means, no. Greywater is required to be discharged 2 inches underground, typically into a mulch basin and cannot be used with a popup sprinkler. However, new technology has provided a means for subsurface irrigation using gray water. Not everyone has bought into “brown is the new green,” and there are many peoples, especially new families, who want to keep their lawns. This is a way to do just that.

What happens to my garden when I travel?

Of course, you can invite your friends and family to come over and use your shower or washing machine when you’re gone; but, if you find that to be a little awkward there are some other solutions. Some kits come with a controller which is also tied into the municipal water system. Any shortfall of greywater is made up for by the municipal system. So, all of the water would be made up during vacation.

Another option, if the house has a controller and irrigation system is to tie a valve into the greywater system. The valve would not be included on the daily watering program. A second program can be created for when people are away that would include that valve.

How do I ensure that my plants are getting the correct amount of water?

We begin by determining how much greywater is generated by the household. Then trees and shrubs, either existing or new, are chosen with their water requirements in mind. The number of outlets then is determined by the amount of greywater generated. Ball valves are placed on the lines so the outflow can be tamped back if necessary. Additionally, all systems can be turned off during a period of heavy rain.

Can greywater work with my current irrigation system?

Usually not. Greywater cannot be sprayed, so if you have a pop-up sprinkler system you cannot tie greywater into it. Greywater has some particles in it, hair, skin, lint, soap. These particles can build up and clog the emitters in a drip system. There are companies that put out a drip line with a double inlet filters designed to resist clogging. There are different drip lines for either sub-surface or mulch application.

Does a greywater system require a lot of maintenance?

A Laundry to landscape system requires very little maintenance. A periodic check of outflow in the mulch basins is really all that is needed. After eighteen months to two years the mulch will breakdown and may need to be changed. Also, if the trees around which the mulch basins were placed were new or young when the system was installed, the mulch basins may need to be moved to align with the drip line of the tree.

Can I store my greywater in the winter to use in the summer?

No, greywater, by law, cannot be stored for more than twenty-four hours. Although greywater has an abundance of the organics in it, once these organics begin to breakdown strong odors are produced.

Do I need to worry about salinization of my soil from the prolonged use of greywater?

There is a need to use environmentally products when using any greywater system. For Laundry to Landscape systems there are recommended detergents to use, a list can be found here. The short answer is do not use powders, use liquid detergents. The powders do contain a large amount of salts and can be very deleterious to the soil. The same is true for bathroom cleaning products. Clorox type products are to be avoided.

Can I water fruits and vegetables with greywater?

Greywater can be used on any foods that do not come in contact with the ground. So, root vegetables, melons and squash are to be avoided. Everything else is fine. We especially like watering tomatoes and fruit trees with our greywater, we have both an L2L and a Filter and Pump system at work and our apples, nectarines, figs and, especially our tomatoes are very happy. We like to think about getting three uses out our water. We wash our clothes, we water and grow a beautiful apple tree, and we enjoy delicious apples from the tree, practically for free. It’s like printing our own money.

What soaps and products can I use with my greywater system?

Plant friendly products are key when reusing your greywater. All products should be biodegradable and non-toxic. In addition, they should be free of salt (sodium) and boron (borax), two common ingredients that are non-toxic to people but are harmful to plants and/or the soil. Chlorine bleach is also harmful to plants and should be diverted with any other harmful products to the sewer or septic by switching the 3-way valve. Hydrogen peroxide bleaches are less harmful and can be used instead of chlorine. Another consideration with soaps and products is their affect on the pH of the water. While many soaps do not change the pH, some do. In general, liquid soaps do not change the pH, while bar soaps make the water very basic (opposite of acidic). Certain acid loving plants may not be happy with this kind of water. If you’re uncertain if the pH is being affected choose plants that are not acid loving to irrigate. Acid loving plants include ferns, rhodedendrons, and blueberries.
Products we recommend: (they are salt and boron free, and pH neutral)

• Laundry: Oasis, Ecos, Biopac liquid detergent, Vaska. There are also soap alternatives that are greywater friendly, like soap nuts, and “wonder balls”.
• Showers: Aubrey Organics makes shampoos and conditioners that don’t have salt or unhealthy chemicals, and are fairly easy to find. In a shower, shampoo is fairly diluted so it is not as important as in the washing machine to have the best products, but it is important to have products that are not harmful to our health, surprisingly many shampoos and conditioners contain carcinogenic chemicals. You can find out what’s in your products at the Campaign for Safe Cosmetic’s on-line database.

What’s different between designing a greywater system for a new construction vs. a remodel or retrofit system?

If you’re building a new house, or doing a full plumbing remodel, you may want to combine all your greywater into one line, and then have a collection tank and pump to distribute it more widely to your landscape.  In retrofit situations it doesn’t usually make sense to combine all the greywater pipes together because it can be very costly. Usually it’s more practical to do each fixture separately and use that water to irrigate the area closest to the fixture.

Which plants should I water with greywater?

In a simple greywater system you want to find a balance between the amount of greywater generated and the water requirements of the plants you’ll be irrigating. Since both these amounts fluctuate, the optimum design strikes a good balance. You want to keep the plants healthy while irrigating as many as possible (to save the most water possible).

Larger plants are better suited to be irrigated with a simple greywater system than smaller plants. Choose the larger plants, such as trees, bushes, berries, shrubs, and larger perennials or annuals. (It’s much more difficult to water lots of small plants that are spread out over a large area with simple greywater systems.) Be sure to use “plant friendly” products in the house, those free of boron and low in salts, then greywater is suitable for any plant that wants to be irrigated.

Graywater Resources

Reuse your water to the fullest.

Agency Guides

California Department of Water Resources Graywater Guide: Using Graywater in Your Home Landscape

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City of Santa Cruz Graywater Rebate Program

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City of Santa Rosa Graywater Rebate Program

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City of Tucson Single Family Residential Gray Water Rebate Program

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San Francisco Public Utilities Commission Graywater Design Manual

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Books and Reports

Builder’s Greywater Guide: Installation of Greywater Systems in New Construction and Remodeling by Art Ludwig

Create an Oasis with Greywater by Art Ludwig

Greywater in California: Design, Managing, and Monitoring 2012 Conference Proceedings

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Legal Graywater Design for Small Scale Applications in California by The Occidental Arts and Ecology

Center WATER Institute – Learn More

Principles of Ecological Design: Integrating Technology, Economics, and Ecology by Art Ludwig

Rainwater Harvesting for Drylands and Beyond by Brad Lancaster – Learn More

Residential Greywater Irrigation Systems in California: An Evaluation of Soil and Water Quality, User

Satisfaction, and Installation Costs by Greywater Action in collaboration with the City of Santa Rosa and

Ecology Action of Santa Cruz – Learn More

Codes and Standards

California Plumbing Code – Learn More

Information about upcoming Greywater changes from the California Building Standards Commission (CBSC)

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Laundry Products

Soap and Detergent Information – Learn More

Non-Profit Organizations

Alliance for Water Efficiency Graywater Introduction – Learn More

Central Coast Greywater Alliance Learn More

Greywater Action Learn More

Greywater Alliance Learn More

Oasis Design Center Learn More

Occidental Arts and Ecology Center (OAEC) WATER Institute Learn More

Pacific Institute Learn More

Regenerative Design Institute Learn More

Wholly H2O Graywater Overview Learn More