Common Ground Garden Supply and Education Center

“Graywater for Green Gardens”

Sherri Osaka, Landscape Architect Sustainable Landscape Designswww.sustainable-landscape.com

19-April-2014

Water Situation in California

Periodic Droughts in California• 1928-1934• 1976-1977• 1987-1992• 2007-2009• 2012-2014

Increases in Water Rates• San Jose (San Jose Water Company) – 2 tiers

– 0-13 CCF $2.52/ CCF– 13+ CCF $2.77/ CCF– Two tiered rates 1-Jan-2010

• Palo Alto – 2 tiers– 0-6 CCF $4.99/ CCF– 6+ CCF $7.58/ CCF

• Los Altos Hills (Purissima Hills District) – 6 tiers– 0-10 CCF - $2.70/ CCF– Over 200 CCF - $9.95/ CCF

Reservoirs – at 33% Capacity Limit• Almaden -- 34%• Anderson -- 60%• Calero -- 42%• Chesbro — 10%• Coyote – 41%• Guadalupe -- 0%• Lexington – 29%• Stevens Creek – 15%• Uvas — 13%• Vasona – 87%

“Rain falls, but Santa Clara County can't catch it all” by Paul Rogers, SJ Mercury, 11-Feb-2010. “New study shows massive earthquake could causeAnderson Dam to fail” by Paul Rogers , SJ Mercury, 5-Jan-2009

Anderson Reservoirhttp://3dparks.wr.usgs.gov

World-Wide Water Use• United Nations

estimates that 13 gallons (50 litres) required/person/day

• U.S. uses 145 gal./person/day

• Average US household of 4 uses about 200,000 gallons per year

• Queensland, Australia – limited users to 35-40 gal./person/dayOne gallon equals 3.8 litres

Energy Used for Water

15-20% of all energy used in California is water related

(cleaning, moving, heating)The State Water Project

Reservoir high in the Hollywood Hills

Sources of Water

• Conservation (!)• Municipal supply• Graywater• Rainwater harvesting• Reclaimed (recycled) water

Conserve first!

CCF = 100 cubic feet1 CCF = 748 GALLONS OF WATER1 CF = 7.48 GALLONS

Check for leaksRead your water meter

One in every 10 homes has a leak that is wasting at least 90 gallons of water per day.

Water Use in Bay Area Home11,000 square foot lot, pool, low water landscape

• About 120,000 gallons per year

• 90,000 gallons inside house

• 30,000 gallons outside house

0

5,000

10,000

15,000

20,000

25,000

30,000

Dec-Feb

Feb-Apr

Apr-Jun

Jun-Aug

Aug-Oct

Oct-Dec

Average

~ 30-50 percent for outdoor use

Water Use in Bay Area Home11,000 square foot lot, pool, low water landscape

• About 103,000 gallons per year

• 85,000 gallons inside house

• 18,000 gallons outside house

Dec-Feb

Feb-Apr

Apr-Jun

Jun-Aug

Aug-Oct

Oct-Dec

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

Average Series3Series4Dec-Feb

< 20 percent for outdoor use

Water Requirements

• High water use– Lawns, birches– 16 gallons of water per

square foot per season

• Moderate water– Fruit trees, Alum root– 8 gallons/sf/season

• Low water– Sages, buckwheats– 4 gallons/sf/season

• Very low– Manzanitas, some oaks– No water once

established

Manzanita berries “Little Apples”

Hydrozoning

Efficient Irrigation

Add Organic Amendments to Soil

• Adding compost to 8-13% of soil by weight significantly increases moisture holding capacity

• Decreases the amount of irrigation

Guidelines for Landscaping with Compost-Amended SoilsCity of Redmond, Washington

Lawn Rebates

• Santa Clara Valley Water District, $1/ square foot

• Lawn Be Gone, $0.75/ square foot• Alameda County Water District, $1/ square

foot

19

What is graywater?

Average Indoor Residential Water Use for 12 North American Cities

Adapted from Residential End Uses of Water, by permission. Copyright ©1999, American Water WorksAssociation and Awwa Research Foundation (AwwaRF).

What is graywater?• Water from sinks,

showers, and laundry machine

• No water from kitchen sinks or dishwashers (no food particles)

• No water from toilets (black water)

• No water from laundry if used to clean diapers

• No water containing any harmful chemicals, including bleachWater expert Larry Farwell estimates that extensive graywater recycling

could save more than 16% of the state's residential water use.

April 19, 2009 LA Times article

Where can you use graywater in the landscape?

• On fruit trees and fruiting vines• On above ground vegetables• On ornamental perennials, shrubs,

groundcovers, and lawns

• Not on root vegetables• Not on seasonally planted annuals• Not in the house (except in Texas)

Is Graywater Irrigation safe?

• 2012 Bay Area Study by Graywater Action*• New $450,000 study: "Long Term Effects of

Landscape Irrigation Using Household Graywater“**

• 1992 $500,000 study*** of eight households in Los Angeles. Checked monthly showed no harmful organisms in soil* Graywateraction.org

** Virginia-based Water Environment Research Foundation & Colorado State University***City of Los Angeles, Office of Water Reclamation (CLA,OWR). 1992. “Gray water Pilot Project: Mid-Course Report”. Los Angeles, CA

Graywater Irrigation

• Advantages– Reduces amount of water needed– Reduces maintenance for septic systems– Reduces load on municipal sewer and

waste water treatment systems– Keeps landscapes alive during drought –

mature landscapes valued at $20/ sq. ft.– Little “infrastructure” as opposed to

recycled water

Graywater Irrigation

• Disadvantages– Not for plants that like acidity – unless

pH is balanced– Need to be careful what you put down

the drain—no chlorine, no boron, no salts, no chemicals

– Liquid detergents (enzymes) better than powders (salts)

History of Gray Water

History of Graywater in California

• 1992 first code included in Appendix F of California Plumbing Code (AB 3518)– After drought

• 1997 second code included in Appendix G (AB 313)

Appendix G: Old California Code• Required permit - ~$500 depending

on municipality• Patterned after septic systems• Costly equipment required: tanks,

filters, emitter• California Plumbing Code (CPC)

Appendix G adoption was OPTIONAL

New California Code - Chapter 16A

• Enacted as emergency regulation in August 4, 2009 (during drought!)

• Included in body of California Plumbing code – Chapter 16A -- not optional

• May be prohibited only after public hearing and enactment of Ordinance

New Code Specifies Three Types of Systems

• Non-permitted systems:– Clothes Washer (Laundry to Landscape)

• Permitted Systems– Simple Systems < 250 gallons– Complex Systems > 250 gallons

Clothes Washer System –Laundry to Landscape (L2L)

Clothes Washer System

• No permit required

• Works for slab foundations

• Washer near exterior wall best

Drawing from: Create an Oasis with Greywater by Art Ludwig

Code Requirements for Clothes Washer System1. Notify the enforcing agency, if required2. Direct graywater either to an irrigation or disposal field, or

to the sewer3. Do NOT connect to potable water or pump or affect other

systems (electrical, fire, etc.)4. Contain the water onsite5. Direct to an irrigation or disposal field6. Do not allow water to pond (surface) or runoff7. Discharge under 2 inches of mulch, rock, or other cover8. Minimize contact with humans and pets9. Send water from soiled diapers or other infectious

garments to sewer10.Graywater should not include hazardous chemicals11.Even if you don’t get a permit, you still have to follow

these rules12.Have a maintenance manual

More requirements

• Keep graywater more than three feet away from ground water

• 100 feet for lakes and streams• 1.5’ to 5’ from property lines• 2-5’ from structures• See code for more setbacks

Washers

Front loaders new15-25 gallons per load

Whirlpool top loader circa 199425 to 44 gallons per load

Typical Washer Connection to Sewer

This is what it looks like

Photo from Deva Luna, EarthCare Landscaping

Stacking washer - inside

Air gap at highest point - outside

Photos from Deva Luna, EarthCare Landscaping

Tighten all connections

Photo Deva Luna, EarthCare Landscaping

Decide where the 3-way goes

Photo Deva Luna, EarthCare Landscaping

Use 1” pipe to avoid overtaxing the washer pump

Photo Deva Luna, EarthCare Landscaping

Cut a hole in the exterior wallSeal it with silicone later

Because this is the highest point, put the air gap assembly here.

Run a PVC line out of the house

This is from the 2nd story

Connect the PVC to 1” black poly tubing

Flexible polyethylene irrigation tubing is a better environmental choice.

Toxic Materials - PVC• Produces hydrogen

chloride gas during combustion

• Toxic manufacture and disposal

• Soft PVC contains phthalates

• Toxic glues• See Bill Moyer report

on YouTube, Bluevinyl.org, and Greenpeace

Alternative to PVC

Blu Lock by Hydro-Rain

Let’s go into the garden…

Percolation Test

Dig a hole and prefill it if the soil is dry

Photos Deva Luna, EarthCare Landscaping

Fill your hole with water

Measure how fast it drains. This soil drained 2 ½” per hour.