graywater gardening

GRAYWATER GARDENING

From Buckets to Irrigation Systems

A detailed guide to help You determine what is best for

Your Garden!

Paul James Just Water Savers USA Inc.

Graywater Gardening © Just Water Savers USA Inc 2010. All rights reserved.

The most important concept of this guide is water re-use efficiency. Diverting washing machine and bath / shower water into a few mulch basins in the garden does save water, but is only about 20% efficient. If you would like to save up to 90% of the water, this guide is for you.

If you put 5 gallons of water in one 4 foot diameter mulch basin every day (150 gallons per month), you have not saved 5 gallons per day

In Tucson, Arizona, that basin only needs 12 gallons for the whole of July for low to medium water-use plants & trees

The actual amount saved is 12 gallons. The irrigation efficiency is 12/150 or 8%. The rest of the water simply drained into the subsoil, wasted

Instead, the 5 gallons per day could be irrigating 90 square feet of garden

A family of four, easily generating 100 gallons of graywater per day, could be irrigating 1,700 square feet in Tucson, or over 2,400 square feet in San Diego

This guide describes many different methods of re-using graywater, their efficiencies and return on investment.

Back to Contents


Graywater Gardening Chapters 1. Introduction

1.1 Putting water saving into context 2. Graywater - 2 minute overview 3. About graywater 4. How graywater moves through soil 5. What plants really want 6. Graywater in the Garden 7. Graywater re-use methods

7.1 Efficiency (overview)

7.2 Buckets

7.3 Hoses

7.4 Branched drain

7.5 Laundry to landscape

7.6 IrriGRAY graywater dripperline

7.6.1 Lawn / turf irrigation

7.6.2 Potable water dripperlines

7.6.3 Comparison with Geoflow

8. Irrigation area calculator

8.1 ETo theory

8.2 Irrigation coverage: Tucson example

9. Graywater Irrigation dripperline installation 10. Plumbing

11. Graywater codes

11.1 Graywater: Friend or Foe?

11.2 State Codes

11.2.1 Wyoming

11.2.2 New Mexico

11.2.3 Texas

11.2.4 Arizona

11.2.5 California

11.2.6 Washington State

11.2.7 Utah

11.2.8 North Carolina

11.2.9 Oregon

11.2.10 Other States Products 1. Water Saving Products & Systems

1.1 IrriGRAY dripperline

1.2 IrriGRAY graywater (gravity) kit

1.3 IrriGRAY graywater (pressurized) kit

1.4 IrriGRAY pumping systems 2. Rainwater Harvesting Products & Systems

2.1 IrriGRAY rainwater (gravity) kit

2.2 Rain Barrel Pump and Hose Kit Useful Links Resources Document Control / Revisions Contact us


Contents

1. Introduction

Irrespective of whether climate change is taking place or not, the simple fact is that America does not have enough drinking water to supply further population (and therefore economic) growth without major rethinking of how we use water, and how we can get the most of out every drop we receive.

The West Coast has been through major drought regularly and was a leader in water re-use until the early 1990's. Most of Australia was in severe drought from the mid 1990's until 2010, and many new water saving techniques had to be developed out of necessity.

Graywater, in particular, has been developed to a point where it is a mainstream practice. It is not just a matter of saving buckets of water here and there, or diverting graywater into a few holes in the garden. The latest techniques use every last drop of graywater, and to greatest efficiency. These techniques save over 4 times the amount of water 'saved' by branch drain and laundry to landscape, yet do not have to cost more than previous methods. This guide provides a thorough grounding on what is possible with graywater. If you are interested in saving water, or simply saving money, this book gives you the tools to determine which approach is best for your property. More than anything else, water use is extremely

Thomson Dam 2008, at 18% of storage capacity. Bui lt to future-proof Melbourne in the 1970's, it could not cope with drought and population growth.

context sensitive. What is best for you certainly won‟t be best for someone in a neighboring state, and may not be best for your neighbor. The most important concept of this guide is water re-use efficiency. Diverting washing machine water into a few holes in the backyard does save water, but is probably only 20% efficient (you actually only save 20% of the water you have diverted). If you would like to save 90% of the water, this guide is for you. 1.1 Putting water saving in context Before even considering re-using graywater, you should ask yourself why? The most common reasons are:

Water shortages - how can I keep my garden alive? High utility costs - expensive watering the garden Reducing the load on your septic system - saving money Going green - attempting to live a sustainable life

If you don't have a garden, re-using graywater within the house requires a treatment system. This doesn't stack up economically if you are connected to a water supply that is relatively inexpensive. In a non-serviced area it can make sense. Or perhaps you want / need to achieve a certain LEEDs level. Untreated graywater irrigation systems are now very affordable and make economic sense, but you must establish the context in which it is installed. If you don't have a garden, or it is extremely low water use, you probably don't need to re-use graywater. Save water instead by installing low flow shower heads and toilets. Consider a high efficiency washing machine (although from a green perspective the carbon footprint of a new-fangled washing machine is considerably higher than the older style machines). If you DO have a garden, think carefully about your total water usage. The following is a great comparison showing how a "whole of property" approach should be considered: Two people live in a San Diego house on a 7,000 square foot lot. They both have 7 minute daily showers and use the washing machine 4 times each week. Their garden requires an average of 5,000 gallons per month for 9 months of the year.

Back to Contents 1. Introduction


using sprinkler heads (very inefficient) with rain sensors, rather than moisture sensors.

Case 1: Using older style shower heads and washing machine, their total annual shower, laundry and garden consumption is 80,950 gallons per year. Let's imagine rebates were offered for a new washing machine (20 gallons per wash), and free replacement shower heads (2 gallons per minute flow), but they continue to water their garden. Their annual consumption drops down to 59,380 gallons, a saving of 21,570 gallons. Case 2: Let's leave everything in place as it was (old shower heads / washing machine), but install an automatic graywater irrigation system, that is 90% efficient. Their annual consumption drops to 35,950 gallons per year, saving 45,000 gallons per year. How can that make sense? Irrigating every day using graywater dripperlines is far more efficient than watering by sprinkler, hose, or reticulation system. 3,000 gallons of graywater per month will achieve a better result for the garden than 5,000 gallons per month of potable water. You will have to read the rest of this guide for the explanation (particularly capillary irrigation effects). I've raised this concept very early in the book because it was a very important issue in Australia. People were changing their shower heads / washing machines, but still irrigating the old way. In most cases it is cheaper and more beneficial to re-use your graywater outside than to reduce your inside home water use. Even in new homes, it is about the same cost (or less) to install a graywater irrigation system than a potable water irrigation system, although a make-up water connection may be required if you don't generate quite enough graywater with low flow amenities. Decide how sustainable you want to be. You may only have enough graywater to support the plants and trees in the garden beds, and not the lawn. Maybe you only have enough to water half of your garden, in which case make-up water could be used, or you decide to irrigate selected areas only. Water conservation is all about knowing what your property needs, and only applying that amount. Don't be tempted to run dual irrigation systems - it invariably results in overwatering. In any of the warmer states, outdoor use exceeds indoor use. Much of the problem is caused by automatic reticulation,

This chart shows summer consumption of water for external use in Western Australia. The dip at the peak resulted from an unusually heavy rain event. The red line shows the amount of water used with automatic potable water reticulation, the blue line shows the amount used with non-automatic systems.

About the Author Hi, My name is Paul James and I am the designer of the IrriGRAY graywater product line. We have installed over 1,000 graywater irrigation systems in Australia, and sold another 6,000 systems via resellers. Our products are now manufactured and sold in the USA. But I have not written this book to sell product (sure, there is a section at the back about our products, and I am proud of the range we manufacture). I have written this guide to help you save more water, by understanding the many ways of re-using graywater in the garden, each with their own pro's and con's. I hope you find this resource useful, and I welcome your feedback. You can email me [email protected] With over 7 years experience in the field, Paul is recognised as leader in the field, invited as expert panellist for Industry Symposiums in Australia and the USA. His graywater dripperline specifications, and ETo / Graywater dripperline efficiency calculations appear in several US state code definitions. Passionate about water, and recognising the rapidly increasing value of water, Paul is focused on educating the general public about using water to its maximum benefit.

Back to Contents 1. Introduction


2. Graywater - a 2 minute overview

This guide contains a lot of information about graywater irrigation for gardens. This section is a summary for those that need a quick overview. Before delving into the concepts, it is important to state that graywater re-use is now relatively easy. New dripperline technology has now made it possible to install a complete residential garden graywater irrigation system (excluding plumbing modifications), to professional standards, in just a few hours. Graywater Graywater is waste water from showers, bath, hand basins and the laundry. It does not include water from the toilet, or laundry if the wash includes soiled items such as diapers. The average person generates over 25 gallons of graywater each day. A family of 4 produce enough graywater to irrigate over 2,400 sq ft of garden in a semi-dry climate such as Southern California. Untreated graywater must be used within 24 hours, otherwise bacteria can multiply to unsafe levels. Treated graywater can be stored, however in most cases treatment systems are uneconomical for residential properties. In areas with infrequent summer rains, graywater is cheaper to harvest than rainwater. If little rain is experienced for a 3 month period, a family of four can re-use over 3,000 gallons per month. An equivalent cistern would need to be at least 9,000 gallons capacity.

Graywater for Gardens Gardens, including fruit and vegetables, do not need fresh potable water. The top level of soil quickly treats the graywater, removing bacteria and contaminants. Experience has shown ornamental, native and food producing plants thrive on graywater, especially when irrigated every day. Sensible precautions should be taken, such as eco-friendly detergents, and avoiding the use of toxic cleaners such as bleach, boron and sodium.

Irrigating with Graywater The most basic irrigation method is using buckets to collect and distribute graywater. This method, while inexpensive, is very inefficient, and prone to overwatering. Sub-surface dripperlines are the most efficient method of irrigation, and can make use of capillary action. IrriGRAY dripperline revolutionized graywater irrigation in Australia, and now has over 90% of the irrigation market there. It is now manufactured and available here in the US. Because of the capillary effect resulting from daily irrigation, dripperline systems are designed to water the whole garden bed - NOT just individual plants. Laundry to Landscape, popularized in California, is time consuming to establish, and significantly increases the risk of washing machine failure. Due to the limited number of irrigation outlets, it is also inefficient, wasting significant amounts of graywater. Diverting Graywater If a new house is being constructed on a slab, graywater stub outs should be installed before the slab is laid. If not specifically requested before construction commences, it is common for builders to combine waste pipes within the slab (to save cost), rendering the waste water unusable. Older houses, or houses built on piers / stumps, can generally be retro-fitted with a graywater irrigation system. Gravity based irrigation systems, built from standard poly tube or branched drain networks are difficult to design and implement. Ongoing tuning will be required to evenly irrigate the garden area. Gravity based graywater dripperlines are easier to install, but should include a surge tank (55 gallons or more) to allow graywater more time to disperse through the drippers. Washing machine graywater can be gravity irrigated in most houses where the washing machine is not in a basement. The washing machine pump is not designed be used to pressurize an irrigation system. Pressurized (pumped) graywater dripperline systems require only small pumping cisterns, as a well designed graywater pumping unit will irrigate at a faster rate than graywater is generated by two showers, or a shower and a washing machine used simultaneously. A pressurized system can easily irrigate a 7,000 sq ft property in a single zone (subject to sufficient graywater production in the house). In most cases, graywater can be pumped 25' uphill and an unlimited distance downhill, without the need for a secondary pumping unit.

Back to Contents 2. Graywater overview


Pump Misinformation Much of the information on US websites has been disproven in Australia over the last 5 - 10 years. While gravity driven irrigation systems (especially graywater dripperlines) are inexpensive and highly efficient, the ideal system for whole of house graywater re-use, (and certainly where the irrigation field/s are uphill from the graywater source), a pumping station will be required. In the past these were expensive, but quality products are now available for around $500-$600. Tens of thousands of graywater pumping and irrigation systems have been installed in the hot and dry Australian climate, without requiring significant maintenance. Some of the sillier claims still promoted on current websites are:

Pumps don't work long without filtration.

Dirty water submersible pumps are designed for ...dirty water. They use an impeller to create a whirlpool in the pump and force the water out with little contact with the impeller. They are designed to pump soft solids up to 1 1/2" or more in size. About 10 years ago there was a common perception in Australia that graywater had to be filtered before the pump, to preserve the pump. This has since been proven false - in over 6,000 systems manufactured and sold in Australia by Just Water Savers (Australia), not one pump has been bound by hair or lint, and this is with filtration after the pump.

Pumps use a lot of electricity, typically being between the number 2 and 5 energy

consumer within the home. A 660 Watt pump, providing more than enough power for residential graywater applications, will typically run for 1/2 hour per day, in total, with 4 people living at the house, and actually only uses 450 Watts during operation. Therefore the total daily power usage is 0.25 kilowatt hours. At say, 11 cents per kilowatt hour (2007 USA average), this comes to a cost of 2.8 cents per day, or $6.70 per year (60.8 kWh). As comparison, this is less than the amount of power consumed by a DVD player, hardly in the top 5 energy consumers in the home. Overall the power usage represents 0.6% of the average home power consumption (based on 2001 USA household electricity statistics). This calculation is based on a graywater system connected to all shower / bath and laundry waste, in operation for 9 months of the year.

3. About Graywater

The average person uses between 20 and 45 gallons per day for simple tasks such as bathing or showering, and using the washing machine.

This doesn't sound like much, but over one month this amounts to over 1350 gallons per person.

In a new house, with new appliances and plumbing fixtures, this figure may drop to about 25 gallons per day, or 750 gallons per month. Graywater is household waste water that includes the following:

- Shower Water - Bath Water - Lavatory (basin) Water - Laundry Water - Untreated Spa Water

Typically, two thirds of the water used in a water-aware household results in graywater (excluding water used for the garden and lawns). Blackwater is household waste water that includes:

- Toilet Water - Laundry Water, if the waste water is from washing diapers, or other materials containing feces

Back to Contents

How much graywater do you produce? This varies from house to house. For most cases, about 60% of water used inside the home would be considered graywater. However, this is largely dependent on personal hygiene practices. As an example, the national average shower usage per person per day is 11 gallons. Yet the average shower using hi flow shower heads (5gpm) is 35 gallons, and low flow is 20 gallons. Combining the two statistics above would mean the average American showers every 2-3 days!

2. Graywater overview


http://www.census.gov/compendia/statab/2010/tables/10s0916.pdf

http://www.eia.doe.gov/emeu/recs/recs2001/enduse2001/enduse2001.html

Darkwater is household waste water from the kitchen. It may contain food contaminants, oils and powerful detergents (especially dishwashers). Although many jurisdictions ban the re-use of kitchen water (darkwater), in some situations this water may be used for garden irrigation IF a grease trap is installed between the kitchen waste outlet and a graywater pumping system. The above definitions apply generally throughout the world, although exact definitions vary from country to country, and in the US from state to state. Practical Graywater Re-use In an urban situation, with a utility provided sewage system, we recommend only re-using shower, bath, spa bath and laundry water. Kitchen and lavatory water is best left for the blackwater waste pipe network. Lavatory (basin) water is in most cases does not provide enough water to justify the connection cost, and in any case provides additional water flow to help flush the blackwater pipe system. In a rural situation (i.e. a septic system is used), kitchen water can be used (subject to local regulations), IF the following occurs: A grease trap is installed between the kitchen sink and the graywater system. This ensures food scraps, fats and oils are not irrigated in the garden. In addition to containing high bacteria levels, the significant quantity of fats can create an impervious barrier within the top soil. The dishwasher does not empty into the kitchen sink waste, because the detergent is too caustic. Graywater Names Graywater is called Graywater, Gray Water, Greywater & Grey water. Although debate is still underway (and will probably never cease), the likely outcome is Graywater in the US, and Greywater in other countries. Fortunately, most search engines now search for all of the above terms if only one is searched. Graywater contains contaminants such as dirt, skin cells, body oils, hair and lint. It also contains bacteria which may present a health risk if not used properly. Untreated Graywater Untreated graywater must be used within 24 hours, and in most jurisdictions can only be used to irrigate gardens. Beyond 24 hours, bacteria will multiply within

the graywater and present an unacceptable health risk. Although the 24 hour rule is applied almost universally throughout the world, graywater can develop offensive odors within several hours, and we recommend not storing graywater at all. This is particularly the case with shower water. The body oils, soap and bacteria interact rapidly, creating a very noticeable odor quickly. Washing Machine graywater is less susceptible to developing odors within 24 hours. Untreated graywater should not in any circumstance be re-used within the house (e.g. bucketing shower water back into the toilet cistern). This creates significant health risks. Treated Graywater Graywater that has either been chemically or UV treated can be re-used within the house, but only in the laundry and for toilet cistern refilling. It can NOT be used for human / animal consumption, nor can it be used to supply water for swimming pools. Prices have been decreasing from $10,000+ down to around $4,000 -$5,000 for a residential toilet flushing system. Larger systems ($10,000 - $20,000) are viable for commercial applications such as Laundromats and Hotels.

Back to Contents 3. About graywater


The WL-55 automatic treatment system, by Water Legacy LLC, Colorado

4. How Graywater Moves through Soil Not many people think about how they apply water to the garden. We have been conditioned to apply water deeply only when the soil or a plant is thirsty / dry. The reality is that watering everyday, with a little water, provides a much better outcome (both in saving water and providing better growth) than watering heavily twice or less per week. Capillary effects are the key. Before reviewing different methods of using graywater, we will spend a few pages on what Capillary Irrigation is, and why it is the most important concept of all. Capillary Action Capillary action occurs when the forces binding a liquid together (cohesion and surface tension) and the forces attracting that bound liquid to another surface (adhesion) are greater than the force of gravity. A simple way of observing this is to take a teaspoon of water and gently pour it in a pool on a countertop. You'll notice that the water stays together in the pool, rather than flattening out across the countertop. This happens because of cohesion and surface tension. Cohesion is the attractive force that pulls similar substances together. In this case, the individual water droplets are being pulled together. The force of the pull is strongest at the edge of the pool. The water droplets at the edge have fewer neighboring water droplets, so they cling more tightly to those around them; this is known as surface tension. Now gently dip the corner of a paper towel in the pool of water. The water is attracted to the paper and "climbs" up the paper towel - this is capillary action. Water behaves almost exactly the same way in soil. If the soil is dry, the surface tension of the edge of the water pool prevents the water spreading outwards quickly.

The effect of gravity pulls the water down, into the root zone, and if there is more water than the roots can take straight away, it keeps going down, into the subsoil and much of it wasted, To summarize, for soil, water moves slowly through dry soil, and relatively quickly through wet / moist soil. How does Capillary Action help graywater irrigation? Because graywater can be irrigated in the garden every day, the soil builds up moisture levels a significant distance from the immediate irrigation point. Water spreads quickly away from the irrigation point, avoiding issues with surface runoff. Note that if the garden soil is very dry, surface runoff may occur. This is common in drought areas, where the soil is so dry it has become hydrophobic (i.e. repels water). Soaps and surfactants in the graywater help to breakdown the water resistance, and surface runoff in most cases ceases within a day.

Wet / dry irrigation requires m o r e c o n c e n t r a t e d dripperlines to enable water to soak into the soil without runoff.

In this example three dripperlines are needed in the garden bed. Moist soil requires only one irrigation dripperline for the same size garden bed. When planning and installing a graywater irrigation system, remember to "water the garden bed, not the plant".

After a few weeks of graywater irrigation on a daily or every second day basis, the top 3" to 6" of soil becomes uniformly moist. Think of this zone as being similar to a water blanket. The water moves freely across the blanket, rather than going down into the subsoil. Because less dripperlines are required, planning and installation is much easier.

Back to Contents 4. Graywater in soil


Dripperlines do not need to be near the plant, and can be as far as 3' away (in loam / clay soil).

The effects of capillary irrigation can be far reaching. My front lawn has under turf graywater irrigation (special dripperlines). This lawn rises up 5 feet from the front of the house to the sidewalk, and I then have a green strip between the sidewalk and the curb. This green strip is another 6" higher than the sidewalk. Even without any irrigation or rain over the hot summer months, my green strip stays green, while neighboring strips go brown. Graywater is being sucked under the sidewalk, uphill into the green strip, all because of capillary action!

5. Understanding what Plants, Shrubs & Trees really want

During times of drought, water purveyors (and horticulturists) all tell us to water deeply, once or twice per week to encourage the plant / tree to send its roots down as far as possible. This is great advice, IF (and only if) there is not a regular water source. What they don't tell you (and should know better) is that if the plants / trees were watered everyday, 30% less water would be required. This is because the plants cannot use lots of water immediately, and a good 1/3 of the water goes down into the subsoil (and keeps going down) unused by your garden. (Their concern is that most people would overwater if they watered everyday - especially if using a garden hose). So if you want to save water - water more frequently, with lesser amounts, every day. But how does this relate to what plants need to grow? What plants need to grow:

Room to Grow, Temperature, Light, Air & Time Water & Nutrients

I can't do much for the room to grow, light, air or time requirements for your plants. But I can explain the basic interaction between water and nutrients. The vast majority of plants and trees receive their water and nutrients via the root structure. Roots can (and want to) travel much further than most people realise.

A diagram from Roots Demystified, by Robert Kourik (Metamorphic Press)

Back to Contents 4. Graywater in soil


Nutrients: Most nutrients are found in the top 3" of soil - the biologically active layer. The further down we go the less nutrients there are. In many soils there is little nutrient loading below 6". It would make sense for a plant to grow most of its root in this layer - right? Water (moisture): When a garden is irrigated daily (with a small amount of water), the top 3" of soil acts like a moisture blanket (see capillary action), the roots and organic matter, together with bacteria in the soil trap the moisture here, right where the roots are also looking for nutrients. However, if the garden is only watered once or twice per week, the roots are trained by you to go as deep as possible, away from the nutrient supply. Therefore, the plant / tree is forced to spend more energy growing more roots than it ideally wants to. There is a common misconception that the roots of a healthy tree extend out to the foliage line. The roots actually extend up to 3 times this distance if the ground has sufficient nutrients and water. Think we are crazy? We have installed over 1,000 graywater systems in Australia (and sold 6,000+ more), with many or our clients being horticulturists. All of our clients report garden health and growth far in excess of gardens being heavily watered (with a lot more water) once or twice per week. But don't just take our word for it, visit R o b e r t K o u r i k ' s w e b s i t e , www.robertkourik.com, he is the expert in obtaining better growth rates with less water. I strongly recommend his book, Roots Demystified (Metamorphic Press), it explains how plants want to grow. You could also research commercial growing locations where they are moving away from deep watering to watering with a small amount every day (some cases every second day). It's why Netafim's (worldwide irrigation system manufacturer) motto is Grow More with Less.

Fertilizer and Soil Amendments: If the existing soil is poor, and holds little organic matter in the first 3", soil amendment should be applied. However, it is vital that the amendment is spread evenly over the entire garden area. This is the opposite of what most people do when they buy a new tree or shrub.

First they dig a hole, a little larger than the root ball of the plant.

Then they throw in some plant food / fertilizer in the hole, add lots of

water and plop the plant in the hole.

If they have a potable irrigation system they then add an extra dripper

right next to the plant. This creates the following problems:

The roots of the plant quickly find an abundant source of food,

therefore they do not need to grow any more to find food.

The roots also have a water source that is wetter below the plant than

the surrounding topsoil. Rather than seeking out water and food, this plant will now need regular feeding, instead of using the soil for food. This diagram was taken from a nursery website - I won’t name them here! Adding soil amendments to the hole creates a growing barrier for the tree roots. I have added the red ellipses to show where the barrier will occur. The roots are encouraged to stay in the nutrient rich environment (in the hole), rather than expanding into the natural soil. If the soil quality is poor, consider broad area fertilization, with mulch and/or slow release fertilizer applied at the surface.

Back to Contents 5. What plants really want


http://www.robertkourik.com

6. Graywater in the Garden

The vast majority of plants thrive on graywater, and the nutrients contained within. The do not need potable water, and perform better with graywater. This chapter outlines how graywater affects plants, and precautions that should be taken to ensure your garden becomes an oasis relying solely on graywater.

Do NOT store graywater for more than 24 hours. Only use laundry detergents that are very low in sodium (salt). Distribute graywater evenly across the garden - don't kill plants with

kindness by over watering. Take care with graywater distribution if using movable hoses connected

to the washing machine outlet. Avoid any cleaners containing Boron - this is toxic for plants.

Remember that what goes down the drain is going onto your garden! Shower Water Shower water contains soap, shampoo and conditioners. The amount of fats, sodium and phosphates in shower graywater is negligible, and has virtually zero impact on plants and lawn. A common misconception is that all graywater is alkaline, and that acid loving plants do not grow as well with graywater.

Azaleas are often quoted as a plant that does not enjoy graywater. Many graywater gardens include Azaleas, and have experienced as good growth, if not better than irrigating with potable water. The pH of shower water is largely dependent on the type of shampoo used. While most shampoos are near neutral pH, some fruit based shampoos can be slightly acidic. Again the effect on pH overall is negligible due to dilution. Typical bar soap has a pH of around 7. Again this is highly diluted within the shower / bath and has little impact on the garden if well dispersed.

Washing Machine Water Washing machines are a popular source of graywater, simply because the inbuilt pump makes it easy to divert the water from the sink to either a surge container with dripperline connected, or directly out to the garden via pipes / hoses. Salt: Non-concentrated soap powders typically contain high levels of sodium (salt), used as fillers. Use only concentrated powders that claim to be low in salt, or use liquid detergents.

Alkalinity: Almost all detergents will produce highly alkaline graywater (pH approximately 10.5) when releasing the first wash water. Repeated application of concentrated highly alkaline water to one or two areas of the garden will kill plants. This is of particular concern when DIY connecting a 1" hose or similar to the wash outlet, and leading the hose to a garden area. A common problem in Australia is the use of a manual gravity fed hose connected to the washing machine - people would move the hose from one area of the garden to another between wash cycles. Being creatures of habit, many people always moved the hose the same way each wash. As a result the

Back to Contents 6. Graywater in the garden


first (dirty and high pH water) ended up in the same area each time, raising the soil pH level and killing plants in the area. We fear this will occur in California due to their unusual requirements for a 'simple' system in the recent CA code update, which appear to encourage this style of irrigation.

However, if graywater is irrigated evenly across the garden, the high pH water will not concentrate in one area, and is in fact partially balanced by the following rinse cycles (the overall pH level of washing machine water (including rinse cycles) is typically in the range of 8.0 - 9.0).

Water Softeners Water softening agents use large amounts of salt. Softened water should not be used in the garden. Graywater for Fruit and Vegetables

Fruit trees and vegetable plants grow well with graywater. The risk is that graywater may contain bacteria, and if you eat fruit and vegetables covered in graywater (and therefore bacteria), you may become sick. If the fruit or vegetable is going to be cooked, any bacteria present will die during the cooking process. This removes the risk.

Citrus trees grow well with graywater, however where possible extend the irrigation area beyond a typical mulch basin, to encourage a wider root coverage.

Because the fruit and nuts on established trees are much higher than ground level, there is very little chance the fruit will come into contact with the graywater. Graywater and vegetables / low fruit Where the edible part of the fruit or vegetable is above ground, and it is eaten raw, the graywater must NOT come into contact with the edible parts. This can be done by bucket (very carefully) but is labor intensive. High flow rate dripperlines (such as Irrigray) apply the graywater directly to the soil zone, and seep into the soil immediately. So long as a layer of mulch covers the dripperline and soil, there is virtually no chance for the edible component to come into contact with the graywater. Where the edible part of the vegetable is below ground (e.g. potato, carrot, onion), graywater will come into contact with the vegetable. If the vegetable is cooked before eating, the risk is removed by the cooking process. If the vegetable is eaten raw, the risk can be reduced by washing the vegetable, peeling, then washing again. We do not recommend growing the following types of vegetables, if they are to be eaten raw: Radish. Because the skin is rough, radish is difficult to clean. Commonly served unpeeled, there is a risk of bacteria remaining on the surface.

A substantial crop of tomatoes, irrigated with graywater. Care is required to ensure graywater does not come into contact with the fruit.

An interesting study concluded that tomatoes are not affected by graywater irrigation.



http://eprints.usq.edu.au/8182/3/Misra_Patel_Baxi_JH_V386_2010_AV.pdf

Salad onion (including scallions etc). Due to the onion's layered structure, there is a chance (albeit small) of bacteria being caught within the onion, presenting a risk if eaten raw. Lettuce is an excellent example of why the first reaction of authorities is to prohibit irrigation of vegetables with graywater. If the lettuce is irrigated by sub-surface dripperline (under a mulch cover), the lettuce leaves will not come into contact with the graywater. However if the lettuce was irrigated with graywater by a watering can, bacteria would collect on the leaves, and present a health hazard as lettuce is rarely cooked, and the cleaning process is unlikely to remove the bacteria.

Common Questions What about soap in the fruits and vegetables? We are yet to find an appropriate scientific study that has measured how much soap is actually contained inside the fruit or vegetable. The consensus view is that only tiny amounts could be present and only at a molecular level. Keep in mind how much the soap / shampoo / conditioner has been diluted by the time it gets to the plant. Consider how much your body is ingesting through other daily activities (brushing your teeth; direct skin absorption of soap, shampoo and conditioners; soap residue on plates that you eat off etc.) Another consideration is how much pesticide do your store-bought fruit and vegetables contain?

Rain water also leaches the soap down into the subsoil, preventing accumulation over the years. Yuck! Eating vegetables with water I have showered in or washed my clothes in! This is a common response - and quite natural. Think about what your vegetables are growing in now; decaying compost, worm castings (and droppings), fertilizer, bird droppings, all manner of less pleasant ingredients than body oils and dried skin. Graywater irrigation of fruit and vegetables is of course personal choice. No one is forcing you to grow your fruit and vegetables with graywater. However, on balance it would appear home grown foodstuffs will have less contaminants than commercially grown produce. My local regulations prohibit or advise against the use of graywater for vegetables. Contact your local health department and find out why. Many regulations / recommendations are written to cope with the most common practices, such as people considering bucketing water onto their lettuce and strawberries etc. This type of irrigation with graywater is risky, because of the potential for bacterial contamination. Graywater dripperline technology has evolved enormously over the last 6 years in countries such as Australia. The new dripperline technology has only recently arrived in the US, and health department regulations or recommendations take many years to catch up. We are not recommending that you break the law. We are simply suggesting thinking about why the law was written in the first place. This chapter is written as general advice, based on our own research and experience. We recommend conducting your own research and / or consult local authorities before deciding what’s best for you.



7. Graywater re-use methods

Previous chapters of this guide have discussed how much water is required by plants, and where the water is needed (top 3" - 6" of soil).

The graywater diversion methods discussed in this chapter all apply the graywater to the soil in different ways, significantly affecting the irrigation efficiency. These are the commonly accepted methods of reusing untreated graywater: - Buckets - Branched Drain (or similar) - Laundry to Landscape - Gravity Dripperline - Pumped Dripperline

Before going into the pro's and con's of each method, the concept of how much water is actually saved needs to be understood.

If you put 10 gallons of water in one 4' hole in the ground every day, you have not saved 10 gallons per day.

In Tucson, Arizona, that hole only needs 12 gallons for the whole of July for medium water use plants. If this was done daily, then 300 gallons has been irrigated over the month, instead of the required 12 gallons. The actual amount saved is 12 gallons. The irrigation efficiency is 12/300 or 4%. This may sound extreme, but I have seen quite a few branch drain systems set up this way (the rest of the water goes down into the subsoil and is wasted, unless trapped by clay in which case the roots of the plants may rot). So while on the surface some methods may appear to be very inexpensive for the amount of water diverted, the amount of water actually saved needs to be reviewed.

7.1 Efficiency (Overview)

Irrigation Method Efficiency Buckets 50% Branched Drain 20% Laundry to Landscape 30% Gravity Dripperline 90% Pumped Dripperline 90% The efficiency rates listed for branched drain and Laundry to Landscape methods are based on typical installation parameters, and can vary by +/- 10% subject to the design and installation experience..

Cost / Benefit Analysis of the different methods. After applying the irrigation efficiencies of the methods, and determining how much potable water is no longer needed to irrigate the garden, these charts can now be presented. If you would like the math behind the following charts, please contact us. Cost vs. Gallons of Potable Water saved over 5 years

Assumptions: Paid labor has been used for installation of all methods except for bucketing of water. A small amount has been added to the bucketing methods, for 1 chiropractic visit (this isn't a joke, it's an ongoing issue in Australia). While voluntary labor (you) can be used to reduce the cost, the efficiency of Branched Drain and Laundry to Landscape methods will typically halve. Those interested in installing their own Branched Drain network should read our detailed section on installing this style of system.

Back to Contents 7. Graywater re-use methods


$0

$500

$1,000

$1,500

$2,000

$2,500

0 100000 200000 300000 400000

Buckets

Branched Drain

Laundry to Landscape

Gravity Dripperline

Pumped Dripperline

Cost per gallons of water saved over 5 years use

This chart illustrates how Dripperline irrigation is far more cost effective over 5 years (at about 0.5 cents per gallon) than even Laundry to Landscape at about 2.5 cents per gallon. It all comes back to how much potable water (irrigation water out of the tap) is saved by each of the methods of diverting graywater.

7.2 Buckets

Buckets are cheap, and with care and effort can be used to water various areas of the garden. Points to consider are: Limited amount of water Most people only use 1 or 2 buckets in the shower. This will capture up to 4 gallons per person per day (not enough for the whole garden - but enough for prized plants). Note a 10 minute shower (the shower would need to run this long to fill the buckets), running at 3 gallons per minute is 30 gallons of water, so 26 gallons of water is used to save 4 gallons. The average person generates between 25 and 40 gallons of graywater per day in the shower, bath and laundry. So buckets are a great start, but only re-use about 10% of the graywater going down the drain.

Over watering

During water rationing, people often concentrate on a limited number of prized plants. Always check the soil moisture level before adding extra water. Killing plants by over watering is a common problem in drought affected areas. Safety

Apart from back problems caused by frequent carrying of buckets in the house and in the garden, beware of spilled water / slipping dangers.

7.3 Hoses

Washing Machines About 5 years ago major Australian hardware chains started selling 1" hose kits. The kit couldn't be simpler, a 1" hose, with a rubber connection on one end and simply open at the other. People simply connected the hose to the outlet, and moved the hose around the garden from wash to wash.

In addition to the high risk of blowing up washing machine pumps (see Laundry to Landscape), with simple hoses such as these, the following were particular problems in Australia:

Over watering / Under watering With simple hoses, all the water (often 40 gallons per wash) is dumped in one small area of the garden, resulting in over watering that area, with other areas going dry. Similar to bucket watering, people would concentrate water in their favorite areas, in the end killing with over watering. Killing plants with high pH water To avoid over watering favorite garden areas, people would move the simple hose between wash / rinse cycles, 'sharing' the water around the garden during the wash. In theory this is fine. In practice people develop a habit of always moving the hose around in the same pattern (e.g. first wash water here, first rinse over there, and the second rinse in the third spot). This is not good for your garden and will kill plants over time.



$0.000

$0.010

$0.020

$0.030

$0.040

$0.050

$0.060

$0.070

Cost per gallon potable water saved over 5 years

Buckets

Branched Drain

Laundry to Landscape

Gravity Dripperline

Pumped Dripperline

Due to high soil pH, micronutrients are bound to the soil and become unavailable to plants. Chlorosis is most commonly caused by iron, but can also be caused by manganese and zinc deficiency. Commonly affected plants are pin oak, sweet gum, white oak, rhododendron, and azalea. The most prominent symptom of iron chlorosis is leaf yellowing. The veins of the leaves stay green, while the rest of the leaves turn yellow.

The issue is primarily the first load of water from the washing machine. Virtually all effective washing powders, 'eco-friendly' or not, need high pH water to wash the dirt from the clothes. The pH of this first amount of water is 10.5. As the washer processes each cycle, the pH of the water in drops. If you were to temporarily store all of the water from one wash, the overall pH is generally between 8.5 and 9.5 which is ok for most gardens.

Always watering in one area with pH 10.5 water will kill plants. If you are going to move a hose around, move in a different pattern each day.

Waste Pipe Diverters / Hoses

These diverters come in many shapes and styles. They divert water from showers (pipe under the house) and laundry (often a vertical pipe on the outside wall). Gravity hoses can then be connected to the diverter valve. Although shower water is basically pH neutral, and therefore removes pH risk, over watering becomes a significant issue, especially when diverting all shower water, and not moving the hose each day. Over watering remains a significant risk for laundry pipe diverter and hose sets. A more sophisticated diversion system is the Branched Drain Network.

7.4 Branched Drain (or similar)

The basic concept is to allow the graywater to flow from the house by gravity alone, typically through 2" pipes. To distribute the water into more than one location, a double Ell (a special type of T fitting) is used to split the flow into two. More double Ells can be used to split the flow further. Theoretically the flow could be broken into 16 or more directions, although 8 is about the practical limit for a typical household (beyond this the pipes and Ells are too sensitive to water flow thus uneven distribution would occur.) This tree has been planted in a large mulch basin, serviced by a branched drain outlet slightly uphill of the mulch basin. The water will flow to the mulch basin via a depression in the ground between the outlet and the basin.

Advantages: Low material cost Many small networks can be made with just $100 worth of materials. Larger systems may cost $400+ worth of materials. Relatively low maintenance: Apart from keeping a good layer of mulch in the mulch basins, the only regular maintenance required is a monthly check of the double Ell's (removing a plug to inspect and clean if necessary). We suggest an annual check to ensure soil settling has not altered the Ell position, resulting in uneven splitting / flow.

A simple, cheap graywater diversion hose, fitted to a rubber funnel inserted into the plumbing bend.



Disadvantages: Irrigation inefficiency: Very low water efficiency, typically the lowest efficiency of any water re-use method. Almost all of the graywater passes through the soil into the subsoil beneath the plant / tree root layer. If this method must be used, trees would be the best candidate. Keep in mind the tree roots will concentrate in the mulch basin, and will not spread far from the base of the tree. Additional feeding (fertilizer) will also be required due to the lack of root growth. Consider a branched drain network with eight 4‟ round mulch basins. The total basin coverage is 100 square feet. While some capillary irrigation will occur outside the basin zone, it will not benefit surface plants because the bottom of the mulch basin is well below the height of the surrounding soil. However, for discussion, lets assume capillary effects double the effective radius of the basin, bring the coverage up to 400 square feet. A typical 3 person household will generate about 120 gallons of graywater per day. A dripperline system (laid under mulch) would irrigate about 2,000 square feet, based on typical planting to suit the locality. Therefore, the branched drain network typically saves 25% or less water than a below mulch dripperline system (either gravity or pumped).

High labor effort required: This method is exacting. The 2" p ipes mus t run t o g rade (approximately 2%) so that water splits properly at the Ell's. Each Ell must be positioned exactly level to ensure even splitting of the water flow. The Ell should also be protected by a valve box (as seen top right) for easy access, and adjustment as required.

7.5 Laundry to Landscape

Laundry to Landscape is a washing machine pressurized irrigation method, popularized in California. The basic concept is connecting a 1" or larger hose connected to the outlet of the washing machine, and running this hose as long as required to reach the irrigation area. Either holes are drilled into the hose, or adjustable valves are then added to allow the graywater to empty into mulch basins around trees and plants. Advantages: Material Cost: This method is relatively low in cost, typically $200+ for materials, + labor. The irrigation layout is less demanding of grade (fall) than the branched drain network. Disadvantages: Reliance on Mulch basins: Because of the relatively limited number of outlets, mulch basins are required to catch the sudden flow of water. As with branched drain networks (although not to the same extent as it is easier to create more basins with Laundry to Landscape), this method is really only suited to trees, and the trees will still require extra feeding due to the limited root growth that will occur. Traditional garden irrigation systems are designed to provide a wet and dry soil moisture cycle. An example of this is watering every second day, with enough water to stop the soil becoming too dry before the next watering cycle activates. The soil is continually moving between wet and dry cycles. Graywater, however, should be irrigated immediately (especially when taken from showers), to prevent odor development. Most people are surprised to find out that daily irrigation makes designing and installing a dripperline irrigation system much easier. Uneven flow rate across irrigation points: The water pressure inside the pipe at each irrigation point will vary according to the flow rate at each point, the distance of the point from the washing machine, and how much water the washing machine is pumping out at any one time.

Back to Contents

Before considering a mulched drain system, we strongly recommend viewing the mulch basin video we have created. Click on the YouTube logo to see a branched drain system installed in Tucson AZ.



http://www.youtube.com/watch?v=0zGkhpA5CX4

Much time and effort is required to tune numerous valves to achieve consistent, even irrigation. Lack of filtration causes clogging.

Washing machines can produce a significant amount of lint and hair. This rapidly clogs any pressurized irrigation system unless additional filtration is used. A simple but reckless solution is to place a filter sock (or similar) on the washing machine outlet. However this places even more load on the wash pump.

An alternative method is to use large holes in the irrigation tube. The large holes won't clog as easily, however tuning such systems to water more than one area takes trial and error to achieve even watering. A garden hose service connection can be used to flush the line at pressure, however may not clean a single blockage if the other holes are clear. Washing machine pumps are NOT built for this.

Plumbers and appliance stores have made a LOT of money in Australia either repairing or replacing washing machines.

About 5 years ago major hardware chains started selling 1" hose kits. The kit couldn't be simpler, a 1" hose, with a rubber connection on one end and simply open at the other. People simply connected the hose to the outlet, and moved the hose around the garden from wash to wash.

Even with a totally open hose (in most cases 30' long), many washing machines failed within 3 years use. Pressurizing the washing machine pump by restricting the flow via valves etc places even more load on the pump. Irrigation inefficiency

To minimize damaging backpressure on the pump, a series of holes / valves are used, ranging from 1/4” to 1” in diameter. To avoid clogging of the holes, at least a 3/8” hole is recommended.

According to the Oasis Design‟s calculator about 10 holes are required to avoid overloading the pump / achieving uneven distribution.

A mulch basin for a tree is typically about 4‟ in diameter, or 12.6 square feet. The total irrigated area with 10 mulch basins will be 126 square feet.

However, assuming an ETo Value of 7” per month (peak summer average across the more heavily populated regions of California), the optimum irrigation area is:

Low water use plants 1,451 square feet (c/w L2L efficiency 8%) Medium water use plants 839 square feet (c/w L2L efficiency 15%) It is possible, if washing is done on a daily or every second day, that capillary irrigation effects will assist, however at best this is likely to double the efficiency of L2L up to 30%. ETo is the evapotranspiration rate. Optimum irrigation area calculations are discussed in Chapter 8 Calculating the optimal graywater irrigation area

Back to Contents

In most cases the ideal number of mulch basins is 10, balancing load on the washing machine vs. even water allocation. At best, the graywater re-use will only be 30% efficient.

Washing Machine pump

Valve

To Sewer

To mulch basins

Vacuum break, either mechanical, or using a line extending at least 6’ above the tee. The 6’ height is to prevent graywater from exiting this line if a mechanical check valve is not used.

Laundry to Landscape schematic This diagram is not an endorsement of the method, and should not be used as a construction guide. Use of this method will void the washing machine warranty.

Mulch Basin Irrigation



http://www.oasisdesign.net/greywater/laundry/index.php#calculator

7.6 IrriGRAY Graywater Dripperline Graywater dripperline is the most efficient method (90%) of irrigating your garden, especially if the graywater is generated daily (or at least every second day), achieving capillary benefits. Graywater dripperline also allows the graywater to be irrigated evenly over large areas of the garden, or across smaller individual garden sections. IrriGRAY dripperline is special graywater dripperline that only requires 400 micron filtration (standard dripperline requires 4 times as much filtration). It has built in emitters every 12" and is connected to a main supply line with a punch tool and takeoff connectors. It can be driven by gravity, or pressurized using a pump. Gravity System The basic concept is to have the washing machine water flow into a temporary surge container, such as a 55 gallon barrel or trash can. Water will irrigate at 1 gallon per minute per 150' of dripperline, even with only 12" of water in the container. A 3/4" supply line is connected to the bottom of the container and run out into the garden areas. Where irrigation is required, the dripperline is connected to the supply line, in any number of independent segments, up to 60' long. The recommended maximum length of dripperline overall is 300', although 150' is most common. As seen in the diagram (top right), more than one area can be irrigated. Advantages: Cost: Excluding the cost of the container, a basic kit can be purchased for approximately $240. (used food grade barrels can be found for around $20 in most areas) Ease of installation / DIY installation: Most irrigation systems can be laid out by two people in under 20 minutes. The barrel / container can be modified in 5 minutes. The dripperline irrigates evenly on flat or sloping ground (but will not flow uphill - it is a gravity system!)

Efficient & even irrigation: 150' of IrriGRAY dripperline has 150 emitters, so graywater is spread evenly across the garden area. Because of this the irrigation efficiency is over 90%, so making the most of your graywater. Plant growth is also stronger, because the plant roots can spread far wider (the entire garden area is moist) and therefore have greater access to nutrients in the top 3" of soil - This was covered earlier in capillary irrigation. Simple maintenance:

Maintenance is limited to one location (the filter outside the base of the container). This filter will need cleaning approximately every 2 months (large filter fitted) or every week (small filter fitted) Disadvantages: Limited irrigation area:

The maximum amount of IrriGRAY dripperline that should be used is 300'. Filter requires regular cleaning:

The small filter will need cleaning on a weekly basis. The optional large filter will need cleaning approximately every 2 months. Both filters are easy to clean, taking no more than 1 or 2 minutes to clean. In our opinion, this is no more (and in many cases less) maintenance than is required by the Laundry to Landscape method. Pumped Dripperline (IrriGRAY) When a powerful dirty water submersible pump (e.g. 660W) is used, graywater can be irrigated over large areas, close to and far from the pump with even drip rates across the whole area. Because gravity is not an issue, the pump can be located at any depth, 42" below ground level is not uncommon. This allows all of the household graywater to be collected, if the plumbing is setup with separate graywater stub outs.



Other systems with very large filters built into the pumping unit are available, however because the filter is an integral part of the pumping container, can be very difficult to access, especially if located in a crawl space or similar. Location of these units can also be problematic, as the most convenient location for maintenance is often the most expensive for plumbing! Large filters are a matter of choice. Some people like them, some don't. Our preference (and our customers) is a filter that is quick and easy to clean every month or two, rather than a big filter that's a hassle to clean every 6 months or so. Some systems are self cleaning - just ensure you understand how they clean themselves, and how much water they use in the cleaning process instead of irrigating the garden.

Advantages: Capability to irrigate large areas, evenly: Customers are re-using up to 10,000 gallons per month using the IrriGRAY pumping and irrigation systems, saving over 15,000 gallons of potable water per month (graywater irrigation is more efficient than potable water irrigation). Improved garden growth: The nutrient laden water, combined with even irrigation, allows strong root growth within the biologically active topsoil. Gardens grow better with Graywater! Maximum collection and reuse of graywater: Because gravity is not an issue, the pump can be located at any depth, 42" below ground level is not uncommon. This allows all of the household graywater to be collected, if the plumbing is setup with separate graywater stub outs. Best long term Return on Investment: Although a completed system may cost $2,000 or more fully installed, in most cases the water savings (and therefore sewerage charges savings as well) provide a payback period of 2-4 years. Savings continue year after year. Easy clean filter: The filter is easy to clean, requiring only 2 minutes per month. Additional filters can be added in parallel to extend the timeframe between cleaning. Disadvantages: Initial cost: With a purchase price of around $1,000, plus installation costs of approximately $1,000 (the majority of which is plumbing cost - this decreases significantly for new homes, or existing homes where the plumbing is easily accessible), the establishment cost is higher than other methods. Regular filter cleaning: The large filter (standard with all IrriGRAY pumping systems) will need cleaning every month to two months (approximately 2,500 gallons).



7.6.1 Graywater irrigation under lawn / turf

To achieve an even watering pattern without striping, subsurface irrigation dripperlines need to be laid closer (12" - 22" depending on soil type) than under mulch IrriGRAY garden bed dripperlines (24" - 48"). With a higher density of dripperline under the lawn, a lower flow rate of 0.6 GPH is used (compared with IrriGRAY garden bed graywater dripperline at 2 GPH). This low flow rate requirement permits the use of Bioline, a specially designed pressure compensating dripperline that also has an inbuilt root barrier in each emitter. Risk of root intrusion is minimized further by frequent irrigation inherent in the use of graywater (grass roots do not seek water if the soil is continuously moist). This diagram shows how to install a combination of garden bed and lawn graywater irrigation. Key Concepts: Bioline does not contain special graywater filters, so an extra 120 Mesh filter (screen or disc type) is required. Instead of locating this filter close to the Graywater Diversion Device (and therefore filtering all of the water from the unit), install it close to the lawn area, so only water for the lawn is passing through the filter. This will reduce the cleaning frequency required. The lawn grid utilizes a 3/4" supply line manifold at each end. Although supply is only required from one end, the manifold is needed at the other end to ensure even water delivery and effective flush valve performance. An Air / Vacuum Relief Valve (A/VRV) is placed at the highest point along the 3/4" supply line / manifold. The function of this relief valve is to allow air into the lines when the pump turns off, and to purge air from the line when the pump comes back on. Due to the wide variety of grasses available it is very difficult to predict the exact amount of water required for a lawn area over the summer. Consult turf providers in your area for expert local advice. Be sure to mention you are investigating Subsurface Drip Irrigation.

To avoid uneven irrigation, where possible align the dripperline along the contours of the lawn area. This may require small sections of infill dripperline if the lawn slope is uneven. To avoid the lawn drying while the house is vacant (e.g. occupants are on vacation), provide a make-up water supply. This can be controlled by simply installing a timer on the laundry or shower faucet, or including a makeup water supply valve in the pumping station and connected to an irrigation controller.



7.6.2 Fresh Water Dripperline & Graywater

Irrigation components designed for fresh water, such as dripperline and weeper hoses, should not be used with graywater that has only had mechanical filtration (i.e. not chemically or UV treated). No matter how fine the mechanical filtration is, graywater still contains suspended / dissolved detergents and dirt. When the graywater dries inside the dripperline or weeper, detergent builds up within the emitter. Over time this builds up and blocks the emitter. An exception to this rule is the shrubbler. Although it will still block with graywater residue, shrubblers are easy to clean. Simply unscrew the top of the shrubbler, allow water to run out and the screw back on. Most households find this needs to be done every six months. Shrubblers are useful for irrigating potted plants with graywater. The shrubbler can be finely adjusted so that not too much graywater is supplied to the plant (excess graywater would drain out of the bottom of the potted plant, and potentially collect on a nearby concrete or brick floor, presenting a slip hazard.)

Additional problems with standard dripperlines Low flow rate: Standard dripperlines flow at a rate of between 0.6 and 0.7 gallons per hour, per emitter. This rate reduces to about 0.4 gallons per hour when supplied with a medium pressure graywater pump (graywater pumps use a vortex to drive the water through the pump, which due to the vortex impeller cannot provide high pressure supply in the same way as a clean water pump). 300 feet of dripperline, with emitters each 12", can only irrigate at a total rate of 2 gallons per minute. Households can easily generate 10 gallons per minute, when both showers are being used, or a shower and the washing machine are running at the same time. If both showers are being used, it is not uncommon for the flow rate to last as long as ten minutes. So if only 300' of standard dripperline is used for graywater irrigation, either a large surge tank (e.g. 100 gallons) should be installed, or the owner must accept a large volume of graywater will be wasted via overflow into either the sewer or septic system.

While 1,000' of standard dripperline improves the situation, a surge tank of at least 40 gallons is recommended. Generating 10 gallons per minute, for 10 minutes and irrigating using 300' of standard dripperline

Generating 10 gallons per minute, for 10 minutes and irrigating using 1,000' of standard dripperline

Generating 4 gallons per minute, for 10 minutes using 300' of standard dripperline

The top two graphs assume a graywater generation rate of 10 gallons per minute. However, problems still occur even with a single shower running at 4 gallons per minute. If 300' of standard irrigation dripperline is used this graph applies.

Using a 20 gallon surge tank, only 35 gallons of graywater could actually be i r r i g a te d . The remainder (approx 60 gallons) was lost to septic / sewer)

Again using a 20 gallon surge tank, 70 gallons of graywater could be irrigated. The remainder (approx 25 gallons) was lost to septic / sewer)



The graphs on the previous page assume the graywater pumping device is empty and turns on instantly when graywater enters the device. When considering purchasing a graywater device, research carefully when and how the device turns on, and what effect the choice of irrigation system has on overflow issues. If you are still temped to use standard dripperlines with a graywater pumping and filtration system, consider the following examples, using an Aqua2use system with standard low flow dripperlines. The Aqua2use system uses a twin sensor arrangement to control when the pumping system is activated. The manufacturer states the capacity of the unit is 20 gallons. During the course of the day, the top sensor is used to activate the pump. This sensor is located approximately 1 inch below the overflow outlet, so the surge capacity once activated is approximately 6% - or 1.2 gallons of graywater - before any additional graywater comes in and flows to sewer / septic instead of being pumped. To illustrate the issue that can occur, 15 gallons or so of graywater can enter the Aqua2use during the day without activating the pump - this can be from a short shower, or graywater supplied by hand basins.

Let‟s now assume someone in the house is about to take a 10 minute shower at 4 gallons per minute. (While appearing to be politically incorrect, our experience is that teenagers commonly exceed 10 minute showers).

In summary, the Aqua2use has 15 gallons already, and a 10 minute, 4 gallons per minute shower is about to happen. I am also assuming that 300' of standard dripperline at an irrigation rate of 0.4 gallons per hour is used. In this case about 38 gallons of graywater is irrigated, with about 18 gallons of graywater lost to sewer / septic.

This improves if 600' of standard dripperline is installed, however blockage of the emitters will still occur over time. 580' of standard dripperline will reduce the wastage to virtually zero, although installation labor and material cost makes this a more expensive proposition. Clearly the low flow rate of standard dripperlines (in addition to other issues) presents a problem in conserving water.

One of the reasons treatment systems can be expensive is the need for large containment tanks to temporarily store graywater as the treatment system can often only treat the graywater at a much slower rate than the peak rate of graywater generation in the house (and in many cases needed 3 tanks for a 3 stage treatment process). This was also the case with older non-treatment graywater systems, with slow irrigation emitters; and why systems were expensive. With new irrigation dripperlines able to irrigate faster than graywater inflow, the pumping / filtration units are much smaller and inexpensive. Because of issues with old irrigation systems, many US states required large tanks / cisterns to be part of any approved graywater system. South Dakota required (and probably still does) capacity for 3 days retention of graywater!



Root Intrusion: The roots of plants, trees and grass will seek out areas of moisture if the ground which they grow in dries out. This is a particular problem for underground irrigation if the irrigation program allows the soil to undergo a repeated wet / dry / wet / dry pattern. If dripperlines are installed below the natural soil surface (e.g. within the root zone), and the soil is watered on an occasional basis (e.g. irrigated twice a week), the roots of the plants will attempt to grow into the source of the water, such as a dripperline which may still contain water inside the tube (as can happen with standard dripperline with small emitters), even if the surrounding soil is dry. For years gardeners (and irrigators) have been taught to irrigate deeply once or twice a week, supposedly to encourage deep growth, even though deep roots do not benefit from the nutrient layer in the top 3" to 6" of soil. As discussed earlier in this guide, this is not the most efficient method of irrigation, as much of the irrigated water continues past the roots and down into the subsoil / aquifer. In any case, the wet / dry cycle encourages roots to enter an underground dripperline system, and herbicides (Treflan is the most common) must be impregnated into the tube to prevent root ingress. When Treflan is used, a small amount of the herbicide leaches out of the dripperline emitter, and results in a golf ball sized root free zone around the emitter. Treflan (common name = Trifluralin) has been banned for all irrigation use in the European Union because of the following concerns: ....due to the high risk for aquatic organisms, especially fish, the toxicity of metabolites to sediment dwelling organisms, the consumer exposure for non-cereal applications, the high persistence in soil, the high potential for bioaccumulation.... Click here to read the decision. Root Intrusion and Graywater Because graywater is normally generated on a daily basis (showers, hand basins and washing machines), a properly designed graywater irrigation system results in a permanently moist 3" - 6" layer of soil. Therefore, the roots of plants do not need to seek out moisture within an irrigation tube. In addition, dripperlines are best installed beneath mulch but on top of the soil layer, as plant roots do not grow above the soil layer.

Because of this, root intrusion barriers / herbicides are not practically required within a graywater dripperline, and in our experience the benefits of added herbicide to a residential dripperline are made for marketing rather than practical purpose, unless the dripperline product is designed to be installed 6" or more below the ground surface.. With over 6,000 graywater gardening irrigation systems (under mulch / on or just below the soil surface) sold in Australia without herbicide we are yet to hear of a single case of root intrusion in over 5 years. I personally will not consider the use of Treflan coated dripperlines for irrigating vegetables or fruit trees on a residential basis. Treflan does has its applications, especially in the municipal / county arena, where staff are properly trained in the use of herbicides / chemicals, potential for leaching, and have been provided with appropriate clothing and equipment. Graywater Slime Build up Mechanically filtered graywater still contains dissolved solids, small particles and bacteria which result in BOD (Biochemical Oxygen Demand). This results in a thin film on the inside wall of the dripperlines. This can create problems for dripperlines using emitters less than 2.0 GPH, as the film also builds up within the emitter itself, and may not be able to cleared by the medium pump pressure of graywater pumps. To overcome this limitation, some dripperlines using a coating of tributyl tin maleate, preventing the slime from attaching to the wall. Using a 2.0 GPH dripperline with a large emitter flow path (such as IrriGRAY) removes the need for anti-slime coatings, significantly reducing dripperline cost. Having sold many thousands of residential IrriGRAY systems in Australia and the USA, we have yet to experience a single case of emitter blockage caused by slime. To summarize: We strongly recommend against using standard / potable water dripperline with untreated graywater.



IrriGRAY IrriGRAY is designed specifically for untreated graywater diversion systems, and can be used in both gravity and pressurized situations. With 2.0 GPH anti-clog emitters, it only requires 40 mesh (or 400 micron) filtration, less than 1/4 that of standard dripperlines. This significantly reduces the need for filtration (and filter cleaning). Detergent build up does no t occur because of the wide emitter path, and because it is designed to be installed on top of the soil (above the roots), below a mulch layer, it does not use / require herbicides. Graywater slime does not build up because the line dries between irrigation periods. Geoflow Geoflow uses a 1.0 GPH emitter, and each emitter is impregnated with Treflan to prevent root intrusion. It can be installed within the root zone, or on the surface below mulch. The inner lining of the tube is coated with the anti-microbial tributyl-tin maleate and a Teflon-like fluoroethylene slip agent, to prevent a slime build-up. Geoflow requires 150 mesh (100 micron) filtration, the same level as most standard dripperlines.

7.6.3 IrriGRAY and Geoflow Graywater Dripperlines

Graywater dripperline is the most efficient method (90%) of i r r igat ing your garden , especially if the graywater is generated daily (or at least every second day), achieving capillary benefits. Graywater dripperline also allows the graywater to be irrigated evenly over large areas of the garden, or across smaller individual garden sections. These specialized dripperlines are designed to overcome the l imi ta t ions of s tandard dripperline, namely; Slow irrigation rate (causing water loss to overflow) Root intrusion Blockage from detergents / contaminants Two graywater dripperline technologies have been proven over years of use: IrriGRAY, and Geoflow. (IrriGRAY is a trademark of Just Water Savers USA Inc.)

Let me declare right now that I have an interest in IrriGRAY. I am one of the founders of Just Water Savers USA Inc, which holds the trademark for IrriGRAY. In a similar vein to Victor Kiam's famous electric shaver advertising slogan ("I liked it so much I bought the company"), I had been using the same product for years in Australia (manufactured and marketed by Netafim Australia as 'Tiran'). Netafim USA manufactures IrriGRAY dripperline to our specification and requirements. Why do I like the product so much that I introduced it to the USA? They both do the job, in their own ways, but IrriGRAY is much cheaper (and easier) to install because of the flow rate and the filtration requirements.

Industry’s Widest Flow Path

Wider cross-section allows large particles

through short flow path

Full Length Filter

Maintains the essential supply of water to the dripper delivering a consistent output of flow

Increased Flow Path Velocity

Commonly used turbulent drippers have overlapping tooth patterns, easily catching debris. Turbonet Technology improves dripper performance by widening the tooth pattern, maximizing flow path velocity, allowing contaminants to pass easily through the dripper, virtually eliminating plugging.

Injection Molded Drippers

Welded into a seamless wall of tubing for added strength, durability and long term performance



Flow Rate Graywater pumping systems provide medium pressure irrigation. IrriGRAY emitters flow at 2.0 GPH at medium pressure. Geoflow emitters flow at 0.7 GPH at medium pressure. In a previous section on potable water dripperlines I discussed the issue of overflow when using a slow dripperline irrigation system, especially using a diversion pumping system that only had a few gallons of capacity before the graywater coming in over ran the system and was lost to waste,

To avoid graywater loss, each type of dripperline requires the following overall lengths: Standard Dripperline 1,500‟ Geoflow Dripperline 900‟ IrriGRAY dripperline 300‟ Price wise, IrriGRAY is about 2/3 the cost of Geoflow (per foot). However, because 3 times as much Geoflow is required than IrriGRAY to ensure no water is lost to overflow, the material cost saving to you is 78%. Installation labor is also reduced by about 50%, saving you time and money.

300' of IrriGRAY dripperline, irrigating at 2.0 GPH, with 10 gallons per minute of graywater entering a pumping system, for 10 minutes. No graywater is lost to overflow.

300' of Geoflow dripperline, irrigating at 0.7 GPH, with 10 gallons per minute of graywater entering a pumping system, for 10 minutes. Approx imately 60 gallons of graywater is lost to overflow.

300’ of Geoflow Dripperline

300’ of IrriGRAY Dripperline



8. Calculating the optimal graywater irrigation area In the previous chapter on capillary action, we have seen that daily irrigation keeps the graywater in the top 3" to 6" of soil, where the plants and trees need the water. However, placing too much graywater in one area will result in graywater leaking into the subsoil, effectively 'lost' as it does not benefit the garden. If the topsoil sits on top of a barrier such as heavy clay, or caliche, too much graywater may result in drowning the roots of the garden. Therefore it is very important to properly determine the correct irrigation area. If you have a small garden, you may not want to re-use all of the graywater generated in your house. This chapter gives a detailed explanation of how to calculate the irrigation area for a given amount of graywater. I will assume that graywater dripperlines are used, as this is the most efficient method of graywater irrigation. Before getting into the math, let's do a simple calculation using the Graywater Calculator (click here to use the calculator on line)

ETo 8 Rainfall 0 Number of People in home 4 Graywater, gallons per person per day 25 The optimal irrigation area is 1,222 square feet.

By changing the Plant coefficient to '0.26 - Low water use' , the irrigation area now increases to 2115 square feet. This is because we still have the same volume of graywater per day, but the plants need less water, so we can grow more plants! Changing the Soil type to 'Medium to Heavy Clay' doesn‟t change the irrigation area, just the amount of dripperline required. This is because soil type does not affect the plant's water requirements.

This is so important I will repeat it again: This is because soil type does not affect the plant's water requirements. No amount of soil or percolation testing alters this irrigation fundamental. If the correct amount of water is applied to the garden, the soil will not be required to carry excess water. During winter or heavy rainfall (adding extra water to the soil), the graywater system should simply be turned off.

Back to Contents 8. Optimal irrigation area


http://www.besthomewatersavers.com/pages/Videos%7B47%7D-Downloads-%7B47%7D-Links.html

All of the examples shown on the previous page assumed each person generates 25 gallons of graywater per day. This is an average figure for people living in a new house, with low flow showers and a water efficient washing machine. The average amount of graywater generated without low flow showers etc is 40 gallons. In this example, four people can easily irrigate 2,000 square feet of garden even in a warm climate and medium water use plants.

8.1 Irrigation Area Coverage Theory

Potable water irrigation calculations determine the amount of potable water required to irrigate a certain area. However, with graywater we know how much graywater we have, and need to determine the garden area that will most efficiently use the graywater. This calculator provides the optimum irrigation area based on graywater production. Throughout this section, it is assumed graywater drip irrigation is used, as it provides over 90% irrigation efficiency. Other methods such as branched drain systems, and Laundry to Landscape (covered in the next chapter) are far less efficient (20% to 40%) and therefore will only irrigate an area 1/4 to 1/2 the area irrigated by dripperlines. The following values are required: ETo (per month) Rainfall (per month) Plant Coefficient Number of people in the house Gallons of graywater per person, per day

ETo (Evapo Transpiration) Evapo Transpiration tells us how much water is required per month to properly account for soil moisture loss via plant growth and plant moisture evaporation. An excellent ET guide is provided online by California Irrigation Management Systems (CIMIS).

This image shows a section of an ETo chart for California.

Large images are available at the CIMIS website.



http://www.cimis.water.ca.gov/cimis/infoEtoOverview.jsp

Contact your local garden shop or irrigator to find out the ETo value for your area. Rainfall The amount of rainfall per month is subtracted from the ETo to determine the monthly water shortfall (i.e. how much additional water is required). Plant Coefficient The ETo value is an estimate of how much water is used by a well watered, full cover grass surface, 3-6 inches in height; used as a reference point for determining water use by other plant types through the application of a plant coefficient. Plant Coefficient Plant Type 0.13 Very low water use 0.26 Low water use 0.45 Medium water use 0.65 High water use Converting inches per month to gallons per month per sq ft The ETo value represents inches per sq ft required per month, but we are working backwards - we need to know how far a certain amount of water will go for the month. The multiplication factor is 0.62 (144 cubic inches per sq ft per inch of rain / 231 cubic inches per gallons) Capillary Irrigation Efficiency The ETo value is based on 100% irrigation efficiency. With standard spray irrigation, much water is lost to surface evaporation and overspray. Typically only 50% efficiency is achieved, so the calculated ETo value would be doubled to account for this. Capillary drip irrigation (mentioned earlier in this guide) has a very high efficiency - over 90%. The ETo rate should be multiplied by 1.1 to account for the 10% inefficiency. The last step is to calculate the correct garden area that can be irrigated.

Formula G = number of people x graywater per person, per day x 30 ET = Evapo Transpiration rate for your area. R = Rainfall for the month being considered. P = Plant coefficient Irrigation area (sq ft) = G divided by ( (ET-R) x P x 0.62 x 1.1 ) The following shows the calculations made for Tucson, AZ. ETo & Rainfall values

Inches required per month (medium water use)

Convert to Gallons per sq ft needed per month



Final value, based on 25 gallons per person per day (Tucson AZ) A 2 person household, with a graywater diversion and irrigation system, can grow a vigorous 470 sq ft garden space with medium water requirement plants, without any additional water during the hottest / driest months. By selecting low water requirement plants, the area can be increased to 813 sq ft. Very low water requirement plants increase the area to 1,627 sq ft. A 4 person household, with a graywater diversion and irrigation system, can grow a vigorous 705 sq ft garden space with medium water requirement plants without any additional water during the hottest / driest months. By selecting low water requirement plants, the area can be increased to 1,627 sq ft. Very low water requirement plants increase the area to 3,254 sq ft. In all cases the garden space can be singular, or a group of smaller garden spaces adding up to the total amount.

8.2 Irrigation Coverage: Tucson

(Source: Tucson Water)

To calculate daily usage patterns, I am making the following assumptions: the average single family residence has 3 residents Very little (if any) water is used in the middle of winter for irrigation Recoverable graywater is 60% of the total internal water use The average volume of graywater generated per person per day = 45 gallons.

As a further assumption (of course every house is different, but the following is a typical approach), 1/3 of the graywater will be used to plant high water use plants 1/3 of the graywater will be used to plant low water use plants 1/3 of the graywater will be used to plant very low water use plants Because there are three people in the house, and I am dividing the garden into 3 different styles of planting, it is easiest to just run the on-line calculator 3 times (one for each person, changing the plant type each time). The predominant soil type in Tucson is caliche, with similar characteristics to medium clay.

The total garden coverage is 2,621 square feet, and requires 600‟ of dripperline. Very light water use plants 1,465 sq ft Low water use plants 733 sq ft Medium water use plants 423 sq ft On a typical Tucson urban lot, this is enough coverage to plant virtually the entire lot, excluding the building, drive and patio hard scapes. Compare this with the typical water use in 2004 (from chart on the left). Although entirely planted, this residence would be saving 23,000 gallons per year. In addition to saving water, the residence will use the air conditioning less, as the property will be substantially cooler with a vigorous garden (c/w the normal heavy planting of decomposed granite i.e. gravel / rock). * Utilization of evaporative water cooler graywater, which can be substantial in July / August, has not been included in the calculations above.



http://www.tucsonaz.gov/water/usage_comparison.htm


9. Installing a graywater dripperline irrigation system This guide assumes the use of IrriGRAY 2.0 GPH graywater dripperline. If using a different flow rate dripperline, adjust dripperline spacing according to the manufacturer's specifications. Step 1 Calculate the average amount of graywater per person. People who are

water conscious generally generate 25 gallons of graywater per day. Less conservative use can be up to 40 gallons (or) per person.

Other factors to consider include the efficiency of the washing machine,

whether low flow shower heads have been installed (check whether the flow restrictors are still in place), and how long the average shower is for the household (including time for hot water to reach the shower).

Establish whether the garden is of a low, medium or high use type. If two

distinct areas of different consumption levels is planned, use the calculator separately for each garden area.

Use the Irrigation Calculator to determine the

optimum irrigation area. A common misconception is that soil type affects the irrigation area. This is not the case for a seasonal graywater irrigation system. The ideal situation is providing enough irrigation supply to allow the plants to grow at the maximum rate, without loading the soil with additional water. During winter (or times of heavy rainfall) the graywater irrigation system should be turned off, and the diversion valve directed to sewer / septic.

Step 2: Determine the total garden area to be irrigated: Add up all the garden areas to be

irrigated (shown in the bottom image as areas of brown).

Compare this area with optimum area

derived from the irrigation calculator. If the garden area is too small for the

amount of graywater generated, consider reducing the number of plumbing fixtures connected to the graywater system.

If there is too much garden area for the

amount of graywater, either find additional water (makeup water) or reduce the amount of garden area to be irrigated.

If the total amount of graywater

dripperline required is greater than 450 feet, the watering areas will need to be broken up into multiple zones.

This is because the amount of water

required to pressurize the dripperline would exceed the volume of graywater normally generated in a typical house at any one time.

If the garden is small and only requires

150' or less of dripperline, consider doubling up the dripperline.

150' of dripperline will only allow up to 5 gallons per minute to be irrigated,

no matter how powerful the pump. If graywater might be generated at 10 gallons per minute, and can only be

irrigated at 5 gallons per minute, graywater could build up in the collection container and overflow to the sewer / septic.

Step 3: Supply line planning: How will the graywater be supplied to the dripperlines? A simple installation may involve a graywater diversion device located near

a side fence, in an area of very low traffic. The 3/4" LDPE supply tube can be led directly to the fence, and along the side boundary as required.

Back to Contents 9. Installing graywater dripperline




Where a graywater diversion device has

been installed on a concrete driveway, or a concrete path at the rear of the house, other options should be considered.

If the floor of the house is elevated (i.e.

has usable subspace), the supply line can be fed under the house - typically through sub floor vents - and emerge at the required garden location. Use of schedule 40 pipe is recommended in place of 3/4" polyethylene under a house, to avoid crush damage by contractors in the future.

Supply line can also be run overhead e.g. along the roof of a garage /

carport, or over the top of a fence / gate (ensure the pump in the graywater diversion device has sufficient head pressure to lift water to these heights).

Important: 3/4" supply line is preferable to 1" supply line, because the 1"

tube holds twice as much graywater as 3/4" tube. 1" line therefore requires more graywater to be generated before the dripperlines become pressurized.

Check with the manufacturer of the graywater pumping system that it 3/4"

supply tube is supported. Many systems do not support less than 1" tube. Step 4: Dripperline layout planning The density of dripperline in a garden bed is

determined by the soil type. As an example, a 6' wide garden bed with

light clay soil requires 2 dripperlines (3.0' separation - 1 line 1.5' from the edge, then 3' to the next dripperline , leaving 1.5' from the other edge).

Important: With daily irrigation of graywater, capillary irrigation ensures the garden bed has a consistent moisture profile. Because of this, the intention is to water the soil, NOT individual plants. Soil Type Separation

Gravel and Sands 1.8‟

Sandy Loams 1.8‟

Loams 2.4‟

Clay Loams 2.7‟

Light Clays 3.0‟

Medium to Heavy Clays 4.5‟

Layout Considerations Inlet pressure Nominal flow Max lateral line length

3' 0.7 GPH 52‟

6' 0.8 GPH 56‟

15' 1.4 GPH 56‟

30' 1.9 GPH 59‟ The maximum lateral line length can be doubled IF the dripperline is

connected to the supply line at BOTH ends of the dripperline. If there is a substantial fall over the irrigated area, where possible try to

locate dripperlines along the contour. Substantial grade (greater than 10%) A graywater diversion system with a 3/4 hp dirty water submersible pump

will provide sufficient dripperline pressure for up to 20 feet differential height in the dripperlines. However, when the pump stops, water already in the dripperlines will naturally flow towards the lowest emitter. Non return valves may be required in uphill supply lines. Only use swing check valves - sprung check valves provide too much flow resistance.

If a contour can't be followed (e.g. a long narrow garden bed running down

a slope), lay supply line along the length of the garden bed, with a number of short dripperlines connected, instead of a single long dripperline.

Ornamental / Fruit trees Trees located in a general lawn area often require more water than those

located in garden beds. Cut a slot in the grass to run supply line, and then connect dripperline in a full circle under the foliage extents.

Cool / Moist areas Some garden beds will require much less water than the majority of the

garden - typically, narrow garden beds shaded by the house for most of the day. Inserting a 16mm valve into the head of the dripperline will allow the householder to vary the flow to such areas as required.

Step 5: Installation Install the supply line and flush the lines if dirt or mud entered the tube

during installation. Layout all dripperlines in their approximate locations, on the soil surface. After laying around plants and trees, connect to the supply lines and peg

into place.



Take care rolling out the dripperline from the coil. If the line is removed from

the coil by pulling instead of unrolling, a helix twist will stay in the tube, preventing the dripperline from laying flat.

Cover the dripperline and garden with at least 2" of mulch, for both

code adherence and water conservation best practice. Step 6: Test Ensure the graywater diversion device has power, and turn on a graywater

source. Check the pump activates as water enters the device. When the pump turns on, you will begin to hear air hissing out of the emitter

holes. If water does not begin dripping, or no air hiss is heard, check the supply

lines to make sure they are not kinked / blocked.

10. Graywater Plumbing Overview

Plumbing and graywater codes vary substantially from one state to the next, even from county to county. IrriGRAY collection & pumping systems have been designed to overcome these challenges by being a flexible design that is constructed on site to suit local codes. In addition to reducing the cost of the manufactured product , our experience is that plumbing installation costs are reduced by 25-40%. The plumber can change the height and location of all inlets / overflows. Additional systems have been developed that are fixed in design and construction. These provide limited flexibility in installation, but have the advantage of fast installation for simple situations. Basic Principles Every graywater collection container must have at least 1 inlet & 1 overflow to sewer or septic. The overflow pipe must be at least the same size as the inlet pipe (or combination of inlet pipes, as more than 1 inlet pipe can be used if this simplifies the plumbing process). Backflow Because of the significant variations between states regarding sewer backflow prevention, most manufactured systems are not supplied with a backflow valve. Graywater Diversion Valve Graywater pumping systems that rely on power to ensure graywater is not stored for over 24 hours (using sensors and an electronic timer / controller) must have a diversion valve located upstream of the pumping station. If graywater irrigation is not required (e.g. during a wet winter), or desired (bathrooms are being cleaned with non garden safe chemicals), simply turn off the power supply to the IrriGRAY system. The unique design of IrriGRAY systems allows the container to empty without using the pump. Some jurisdictions may still require installation of a graywater diversion valve before the container, due to specific code requirements. The use of three way Jandy pool valves is being allowed in many states, although the valve does not conform to code (it is not certified for drainage, waste and vent (DWV) use). Some jurisdictions are not permitting the use of Jandy valves. Gate valves or similar, used either before the graywater enters the pumping station, or as parts of the station design are certified for DWV use.



Graywater stub out height vs. sewer pipe height Try to minimize the depth of the graywater stub out, this will simplify

installation and reduce material costs.

Where possible, design the drainage plumbing so that the graywater stub out is at least 14" above the sewer pipe level.

This allows the container to drain completely to sewer without using the pump - a requirement is some jurisdictions.

Some states do not require the ability to completely drain by gravity in which case the height differential does not have to be substantial. However the better engineering design is to enable the container to empty by gravity alone. Pump outlet swing check valve If the pump is located below one or more areas of dripperline, fit a swing check valve in an accessible location after the pump and before the irrigation system. This will prevent air being brought back into the pumping chamber if water is drawn back by gravity. RP backflow valve Although not specifically mentioned in many graywater codes, a reduced pressure backflow valve is more often than not required within the plumbing code. This valve must be installed at the entry of the service supply to the property. Many jurisdictions are now requiring RP backflow valves for any of the following situations (a good example is Tucson Water: Backflow prevention requirements): Use of a reticulated irrigation system (even with potable water)

Installation of ponds / fountains etc

Installation of any pressurized alternative water source (e.g. graywater re-use, or rainwater harvesting cistern with a pump connected).

Sewer backflow valve Check local authorities for the type of backflow prevention device required. Hand Basins When retrofitting a graywater system to an existing house, it may not be cost effective to connect hand basins, due to the low volume of water produced. Even if new houses, fitted with low flow shower heads and washing machines, it may be preferable to keep the hand basins on the blackwater waste plumbing to provide additional flush volume.

The 3" stub out for this house is 42" below ground (Tucson AZ)

An IrriGRAY 18" diameter x 30" deep pumping station has been used, with 2 x 12" extension collars.

The diversion valve is readily accessible, and because the basin station is self cleaning, only an annual inspection is required.

The float valve is part of the make-up water supply system.

The total cost of the pumping station and irrigation system was less than $1,200. Plumbing installation was completed in under 2 hours.

Back to Contents 10. Graywater plumbing


http://www.tucsonaz.gov/water/docs/isbf-req.pdf

Filtration after the pump Older design water pumps could not pump solids such as hair and lint. Most early graywater pumping systems placed filter media before the pump.

Because water can only pass through the filter by gravity, it slows down as the filter collects solids, and the water drains via the overflow before it can pass through the filter. New graywater capable pumps can process hair, lint and other solids with ease. Therefore, filtration necessary for graywater dripperline irrigation can be placed AFTER the pump.

Because water is pumped through the filter, instead of relying on gravity, the potential for overflow loss is significantly reduced.. By having the filter away from the pumping unit, the pumping unit can be positioned in the most suitable plumbing location. So it doesn't matter if the pumping unit is installed subfloor, because the filter can be located in a more convenient and accessible location, so long as it is placed in line before the first dripperline segment.

With IrriGRAY dripperline, only 40 mesh (400 Micron) filtration is required before the graywater arrives at the dripperline / irrigation field. The challenge for filter designers is to make the filter big enough so that it doesn't need cleaning too often, yet without being so big it is clumsy and difficult to clean. The IrriGRAY filter typically requires cleaning once every 1 - 2 months. It is easy to clean and takes only a minute to remove, clean and refit. Because the filter is installed AFTER the collection / pumping system, it can be placed anywhere that is easy to access; before the irrigation network. The IrriGRAY filter is designed specifically for IrriGRAY graywater dripperline. It should not be used for regular dripperline without adding an extra, finer, filter.

Filter media located before the graywater pump.

Filter media located after the graywater pump.

IrriGRAY 40 mesh / 400 micron filter

Back to Contents 10. Graywater plumbing


An excerpt from Australian Government; National Water Commission: Urban Greywater Design and Installation Handbook

http://www.nwc.gov.au/resources/documents/GREYWATER_handbook_nwc_logo.pdf



11. Graywater Codes

Introduction Code can be difficult to deal with. At times, code development seems painfully slow, taking at least 2 years in some states to move from inception to adoption of code and supporting regulations. Whatever you do, treat your local official/s with respect. They may understand your reasoning, but they can‟t always support you in being sustainable. That is a job for the elected representatives. Not only is national standards work underway (IAPMO - International Association of Plumber and Mechanical Operators, and ICC - International Code Council), but various states are in a constant state of updating / modifying their codes. On top of this, many counties and cities are adopting their own codes and regulations, in some cases easing regulations, in others making re-use of graywater more difficult. Other times, code is implemented without coming onto the radar - it just happens. It sure makes life interesting for a national manufacturer; in the end we just design the best practical solution and make it adaptable to fit the differing code requirement of different locations. Even in Australia, a national standard took years to develop, and some states / locations still have their own peculiar requirements. Thankfully for Australia, sub mulch (but on top of soil) irrigation is effectively the standard, officially recognised as being both safe and environmentally best practice. So why is their such an issue with code differences here in the US?

This chart is courtesy of Todd Jarvis, who has been involved in graywater committee work for Oregon. Todd has an excellent blog, and I recommend his frequent writings.

11.1 Graywater: Friend or Foe? Ok, if you have read through a few pages of this guide already, you might correctly assume I consider graywater to be our friend. I am, however, focussed on sustainability rather than corporate / municipal dollars and sense. I want my kids to live well, in a prosperous and rewarding country. What makes me happy, doesn‟t necessarily make others happy. Graywater is a friend for: States / cities / counties with a severe water shortage or water infrastructure

issue. Heck, if customers can use less water and still be happy they can save their expensive gardens, who wouldn't be happy - unless re-use is too successful and cuts into revenue?

Customers (most likely you!) You have already paid for the water once - why can‟t you use it the way you want - a perfectly logical argument. If you are charged a sewer cost based on consumption, it makes even more sense to use graywater instead of potable water on your garden.

Graywater is a foe for: Health officials and engineers who view graywater as a nuisance rather

than an opportunity. This is THE big one. Despite millions of people reusing graywater for at least half a century across the world, for both ornamental and consumption irrigation, without any reported incidences of health issues, the official is there to protect you from becoming sick from re-using water you have generated yourself on your property, so that if you have an illness, you can‟t re-infect yourself with an illness you already have (and no that doesn‟t make sense to me either). The critical point is how code and regulations are defined. If the regulations are too prescriptive, then the onus is on the official (a problem for the official, because possibly not enough detail was written into the code). If the codes and regulations are outcome based , then responsibility lays with the manufacturer / installer / property owner.

Water purveyors with treatment plants / infrastructure. As an example, Southern Nevada does have the infrastructure to capture each drop of effluent / graywater, treat it and re-supply to customers as fresh water. They have a limited allocation from the Colorado basin, which they are presently re-using (and charging for) approximately 3 times.

Back to Contents 11. Graywater codes


http://rainbowwatercoalition.blogspot.com/

This is logical up to the point that over 70% of residential water use is external, and of that 30% is wasted via incorrect irrigation methods. (SNWA water use facts) From their perspective, they are more efficient at re-using (treating) the water at the municipal plant, and when compared to in-efficient graywater re-use methods (branched drain = 20%, Laundry to Landscape = 30%) , they are correct. . However, when graywater re-use methods (dripperline) is at 90% efficiency or above, then on-site graywater re-use is better overall for the catchment. The numbers don‟t add up. For each 100 gallons consumed, (internal and external use), only 30 gallons is returned for treatment. Therefore the net use at the residence is 70 gallons. If a graywater irrigation system was installed, with an appropriate garden design, and 0 gallons potable water used for irrigation, the net use would be 30 gallons.

Water company’s business models Most water companies are public service monopolies that are established to provide a reliable service on a non profit basis. Reducing consumption through conservation plays havoc with their bottom line. When people conserve, rates have to rise to makeup the shortfall in revenue. I highly recommend this article by Brett Walton / Circle of Blue. It discusses the conundrum of short term cost of conservation vs. the long term benefits of water conservation.

Good code vs. Bad Code Good Code defines the outcome, without defining how to get there. On this basis, pumping stations are designed in accordance with plumbing

codes. Irrigation systems are designed to avoid surface pooling by irrigating an

appropriately sized area based on planting requirements, rather than specifying the irrigation must occur 6” under ground (beneath the root zone for many plants).

Good code doesn't make conservation expensive, by requiring expensive documentation, and official site inspections - if best management practices are followed (e.g. ETo based irrigation design)

Bad code is most commonly derived from sewer / septic regulations that focus on disposal of graywater, instead of maximizing the benefit of graywater.

11.2 State Codes Rather than listing and discussing various state codes in alphabetical order, they are listed in order of effectiveness (best to worst). You can jump to any code directly by clicking on these links:

11.2 State Codes

11.2.1 Wyoming

11.2.2 New Mexico

11.2.3 Texas

11.2.4 Arizona

11.2.5 California

11.2.6 Washington State

11.2.7 Utah

11.2.8 North Carolina

11.2.9 Oregon

11.2.10 Other States Only sections of code related to the re-use of graywater in a residential setting are quoted.

11.2.1 Wyoming This is the most common sense code in the US. It is does not proscribe how greywater is to be collected or irrigated - instead is provides basic guidelines of what must be avoided (human / animal contact etc). Wyoming does allow for aerated irrigation of graywater, as long as their is

no risk of contact with humans, animals and edible crops (by spray). This is a common sense approach for a state which is sparsely populated.

In some areas of Australia, aerated irrigation is now permissible, if the

irrigation is in large droplet form and not misted. This simple requirement recognises that graywater will not be blown onto neighboring properties if the drops are of a reasonable size.

This code does not appear to prohibit the use of graywater for produce

irrigation if the graywater is not sprayed (e.g. drip irrigation) A permit / fee is not required.



http://www.snwa.com/html/cons_waterfacts.html


http://www.circleofblue.org/waternews/2010/world/u-s-urban-residents-cut-water-usage-utilities-are-forced-to-raise-prices/

Chapter 3, Section 8 - Permit by Rule Greywater Added - Policy 11.1 Greywater defined: 1. Household wastewater which has not been contaminated by toilet discharge (blackwater). Greywater includes wastewater from baths, showers, bathroom wash basins, clothes washing machines, sinks (including kitchen sinks) and laundry tubs. Greywater re-use systems that match the following conditions will be permitted on a "permit by rule" system as described in chapter 16 of the State of Wyoming Water and Wastewater Rules. That is to say that no application for a permit or fee is required if all the following conditions are met:

1. Human contact with the greywater will be minimal.

2. Water which has been used to wash diapers or similarly soiled or infectious garments is not allowed into the greywater system unless the greywater system is designed to prevent human or animal contact.

3. Greywater does not come in direct contact with or adversely impact

surface or groundwater.

4. The potable water system must be isolated from the greywater system by the appropriate backflow methods and devices.

5. Greywater does not leave the property on which it is generated without written, legally recorded, permission from all land owners affected.

6. Water which contains hazardous materials cannot be disposed of in a greywater system.

7. Greywater sprayed into the air for irrigation or other purposes during high wind conditions cannot come into contact with humans, domestic animals or the edible portion of food crops during normal operation.

8. The application of greywater minimizes the pooling of water on the ground surface.

9. Greywater holding tanks, if used, shall be covered or otherwise protected from access by mosquitoes, children, animals, or other life forms.

10. The volume of greywater produced does not exceed an average of 2000 gallons per day.

11. In addition, at least one of the following conditions must also be met:

(a) The greywater system has been constructed to allow diversion of

the flow to the black water disposal system, and the blackwater system (septic tank, sewer, etcetera) is sized adequately for both greywater and blackwater or:

(b) The greywater system has been constructed to allow diversion of the flow to a secondary greywater disposal system, and the second greywater system is constructed and operated within the guidelines defined above. The secondary system shall be designed and operated in such a manner that extended freezing temperatures will not cause failure. This option is required when a traditional blackwater disposal system is not present, such as when an incinerating toilet or composting toilet is utilized.

Greywater systems that do not meet the above criteria shall submit a permit application to the State of Wyoming Department of Environmental Quality to be evaluated on an individual basis.

11.2.2 New Mexico A remarkably simple code, for residences applying less than 250 gallons per day of graywater. Aeration of graywater is not allowed. Unlike some states mentioned later in this chapter, rather than specifying

soil loading figures, New Mexico simply states „to ensure that the hydraulic capacity of the soil is not exceeded‟

Produce irrigation is not prohibited. No permit is required. Section 2. Section 74-6-4 NMSA 1978 (being Laws 1967, Chapter 190, Section 4, as amended by Laws 2001, Chapter 240, Section 1 and by Laws 2001, Chapter 281, Section 1) L. shall not require a permit for applying less than two hundred fifty gallons

per day of private residential gray water originating from a residence for the resident's household gardening, composting or landscape irrigation if:

(1) a constructed gray water distribution system provides for overflow

into the sewer system or on-site wastewater treatment and disposal system;

(2) a gray water storage tank is covered to restrict access and to eliminate habitat for mosquitos or other vectors;



http://deq.state.wy.us/wqd/www/Permitting/Downloads/GWPolicy.pdf

http://www.legis.state.nm.us/Sessions/03%20Regular/FinalVersions/house/HB0114.htm



(3) a gray water system is sited outside of a floodway;

(4) gray water is vertically separated at least five feet above the ground water table;

(5) gray water pressure piping is clearly identified as a nonpotable water conduit;

(6) gray water is used on the site where it is generated and does not run off the property lines;

(7) gray water is applied in a manner that minimizes the potential for contact with people or domestic pets;

(8) ponding is prohibited, application of gray water is managed to minimize standing water on the surface and to ensure that the hydraulic capacity of the soil is not exceeded;

(9) gray water is not sprayed;

(10) gray water is not discharged to a watercourse; and

(11) gray water use within municipalities or counties complies with all applicable municipal or county ordinances enacted pursuant to Chapter 3, Article 53 NMSA 1978

11.2.3 Texas Although the Texas code is less easy to read than other codes, such as New

Mexico and Arizona, it does not prohibit the use of graywater for irrigating produce.

No authorization is required for the domestic use of less than 400 gallons of

graywater each day. It is interesting that substantial focus is placed on using graywater to

maintain moisture levels around building foundations to prevent movement / cracking. This is also common practice in Australia.

The following is an excerpt relevant to residential graywater re-use. SUBCHAPTER F: USE OF GRAYWATER SYSTEMS §§210.81 - 210.85 Effective January 6, 2005 Adopted December 15, 2004 Effective January 6, 2005

§210.82. General Requirements. (a) Graywater is defined as wastewater from:

(1) showers; (2) bathtubs; (3) hand washing lavatories; (4) sinks that are not used for disposal of hazardous or toxic

ingredients; (5) sinks not used for food preparation or disposal; and (6) clothes-washing machines.

(b) Graywater does not include wastewater from the washing of material,

including diapers, soiled with human excreta or wastewater that has come into contact with toilet waste.

(c) Construction of a graywater system, including storage and disposal systems, must comply with this chapter and any requirements of the local permitting authority.

§210.83. Criteria for the Domestic Use of Graywater. (a) An authorization is not required for the domestic use of less than 400 gallons of graywater each day if:

(1) the graywater originates from a private residence;

(2) the graywater system is designed so that 100% of the graywater can be diverted to an organized wastewater collection system during periods of non-use of the graywater system and the discharge from the graywater system must enter the organized wastewater system through two backwater valves or backwater preventers;

(3) the graywater is stored in tanks and the tanks:

(A) are clearly labelled as nonpotable water; (B) must restrict access, especially to children; (C) eliminate habitat for mosquitoes and other vectors; (D) are able to be cleaned; and (E) meet the structural requirements of §210.25(i) of this title

(relating to Special Design Criteria for Reclaimed Water Systems);

(4) the graywater system uses piping that meets the piping

requirement of §210.25 of this title; (5) the graywater is applied at a rate that:

(A) will not result in ponding or pooling; or (B) will not cause runoff across the property lines or onto any



http://www.tceq.state.tx.us/assets/public/legal/rules/rules/pdflib/210f.pdf

paved surface; and

(6) the graywater is not disposed of using a spray distribution system.

(b) Builders of private residences are encouraged to:

(1) install plumbing in new housing to collect graywater from all allowable sources; and

(2) design and install a subsurface graywater system around the foundation of new housing to minimize foundation movement or cracking.

(b) A graywater system as described in subsection (a) of this section may

only be used:

(1) around the foundation of new housing to minimize foundation movement or cracking;

(2) for gardening; (3) for composting; or (4) for landscaping at the private residence.

(d) The graywater system must not create a nuisance or damage the quality

of surface water or groundwater. (e) Homeowners who have been disposing wastewater from residential

clothes-washing machines, otherwise known as laundry graywater, directly onto the ground before the effective date of this rule may continue disposing under the following conditions.

(1) The disposal area must not create a public health nuisance. (2) Surface ponding must not occur in the disposal area. (3) The disposal area must support plant growth or be sodded

with vegetative cover. (4) The disposal area must have limited access and use by residents

and pets. (5) Laundry graywater that has been in contact with human or animal

waste must not be disposed onto the ground surface. (6) Laundry graywater must not be disposed to an area where the

soil is wet. (7) A lint trap must be affixed to the end of the discharge line.

(f) Graywater systems that are altered, create a nuisance, or discharge

graywater from any source other than clothes-washing machines are not authorized to discharge graywater under subsection (e) of this section.

11.2.4 Arizona Arizona has applied a 3 tier approach, based on volume of graywater per day,

and level of treatment required. Graywater may not be used for food production, other than citrus and nut

trees. Irrigation by flood or drip only.

Arizona does allow individual jurisdictions to modify the code „C. Towns,

cities, or counties may further limit the use of gray water described in this Section by rule or ordinance.‟

Tier 1 (less than 400 gallons per day) does not require a permit. R18-9-711. Type 1 Reclaimed Water General Permit for Gray Water A. A Type 1 Reclaimed Water General Permit allows private residential direct reuse of gray water for a flow of less than 400 gallons per day if all the following conditions are met:

1. Human contact with gray water and soil irrigated by gray water is avoided;

2. Gray water originating from the residence is used and contained within the property boundary for household gardening, composting, lawn watering, or landscape irrigation;

3. Surface application of gray water is not used for irrigation of food plants, except for citrus and nut trees;

4. The gray water does not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities;

5. The application of gray water is managed to minimize standing water on the surface;

6. The gray water system is constructed so that if blockage, plugging, or backup of the system occurs, gray water can be directed into the sewage collection system or on-site wastewater treatment and disposal system, as applicable. The gray water system may include a means of filtration to reduce plugging and extend system lifetime;

7. Any gray water storage tank is covered to restrict access and to eliminate habitat for mosquitoes or other vectors;

8. The gray water system is sited outside of a floodway;



http://www.azsos.gov/public_services/title_18/18-09.pdf

9. The gray water system is operated to maintain a minimum vertical

separation distance of at least five feet from the point of gray water application to the top of the seasonally high groundwater table;

10. For residences using an on-site wastewater treatment facility for black water treatment and disposal, the use of a gray water system does not change the design, capacity, or reserve area requirements for the on-site wastewater treatment facility at the residence, and ensures that the facility can handle the combined black water and gray water flow if the gray water system fails or is not fully used;

11. Any pressure piping used in a gray water system that may be susceptible to cross connection with a potable water system clearly indicates that the piping does not carry potable water;

12. Gray water applied by surface irrigation does not contain water used to wash diapers or similarly soiled or infectious garments unless the gray water is disinfected before irrigation; and

13. Surface irrigation by gray water is only by flood or drip irrigation.

B. Prohibitions. The following are prohibited:

1. Gray water use for purposes other than irrigation, and

2. Spray irrigation.

C. Towns, cities, or counties may further limit the use of gray water described in this Section by rule or ordinance.

11.2.5 California After many years of illegal graywater re-use by Californians, the code was substantially re-written. Unfortunately many sections of the code encourage inefficient (i.e. wasteful) practices, and actively discourage best management practices. I will explain why after listing the major points of the code. Rather than repeat the whole code here (it is 12 pages long!), here is the link: January 27, 2010 (2007 CPC, Title 24, Part 5, Chapter 16A, Part I – Nonpotable Water Reuse Systems) The following is a collection of excerpts that summarize the code. Keep in mind “a city, county, or city and county or other local government may,

after a public hearing and enactment of an ordinance or resolution, further restrict or prohibit the use of graywater systems. For additional information, see Health and Safety Code Section 18941.7.” General definitions: "Graywater" includes but is not limited to wastewater from bathtubs, showers, bathroom washbasins, clothes washing machines, and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers. Mulch Basin. A type of irrigation or disposal field filled with mulch or other approved permeable material of sufficient depth, length and width to prevent ponding or runoff. A mulch basin may include a basin around a tree, a trough along a row of plants or other shapes necessary for irrigation or disposal. Irrigation Field. An intended destination for graywater in the receiving landscape including but not limited to a drip irrigation system, mulch basin, or other approved method of dispersal for irrigation purposes. Requirement for 2” covering In general, any irrigation system must avoid graywater contact by being covered with 2” of material:

(G) Graywater shall not be used in spray irrigation, allowed to pond or runoff and shall not be discharged directly into or reach any storm sewer system or any surface body of water.

(H) Human contact with graywater or the soil irrigated by graywater shall be minimized and avoided, except as required to maintain the graywater system. The discharge point of any graywater irrigation or disposal field shall be covered by at least (2) inches (51 mm) of mulch, rock, or soil, or a solid shield to minimize the possibility of human contact. (I) Graywater shall not be used to irrigate root crops or edible parts of food crops that touch the soil.

The code describes three types of systems: Clothes Washer System. A graywater system utilizing only a single

domestic clothes washing machine in a one- or two-family dwelling. This method cannot use a secondary pump and relies either on the washing machine pump or gravity to irrigate the garden areas. The amount of water from the washing machine is considered to be 15 gallons per person per day, e.g. 60 gallons per day for a 4 person household.



http://www.hcd.ca.gov/codes/shl/2007CPC_Graywater_Complete_2-2-10.pdf


A construction permit is not required for the Clothes Washer System A construction permit shall not be required for a clothes washer system which does not require cutting of the existing plumbing piping provided it is in compliance with Section 1603A.1.1.

Simple System. A graywater system serving a one- or two-family dwelling

with a discharge of 250 gallons (947 L) per day or less. Simple systems exceed a clothes washer system. A construction permit is required for a simple system.

Complex System. Graywater systems that discharge over 250 gallons

(947L) per day. A construction permit is required for a complex system.

Construction Permits 1603A.0 Permit.

A written construction permit shall be obtained from the Enforcing Agency prior to the erection, construction, reconstruction, installation, relocation or alteration of any graywater system that requires a permit. No construction permit for any graywater system shall be issued until a plot plan with appropriate data satisfactory to the Enforcing Agency has been submitted and approved. When there is insufficient lot area or inappropriate soil conditions to prevent the ponding or runoff of the graywater, as determined by the Enforcing Agency, no graywater system shall be allowed.

1604A.0 Drawings and Specifications.

Graywater systems for which a construction permit is required may be subject to submittal of plans and details of the proposed graywater system necessary to ensure compliance with the requirements of this chapter.

Identification of the groundwater level and soil absorption qualities at the site shall be included in the plans or provided to the Enforcing Agency.

1605A.0 Inspection and Testing.

(A) Inspection. A graywater system for which a construction permit is required shall be subject to inspection by the Enforcing Agency and such construction or work shall remain accessible and exposed for inspection purposes until approved. (B) In order to determine the absorption quantities of questionable soils other than those listed in Table 16A-2, the proposed site may be subjected to percolation tests acceptable to the Enforcing Agency. Exception: Irrigation fields in compliance with Section 1611A.2, which only utilize drip type emitters.

Summary: A washer machine system, without an extra pump, producing 60 gallons per

day, does not need a permit. Any other style of system e.g. re-using shower water, or using a pump, must

have a construction permit. Construction permits require a plot plan with supporting data, drawings and

plans of the graywater system, and a site test by the agency after installation. If drip emitters are not used a percolation test will be required as well.

Discussion Washer Machine System The code does not define how the water is to get from the washer machine to the irrigation area, nor how it enters the soil (other than 2” cover must be present, and ponding / runoff must not occur). However Laundry to Landscape (L2L) is promoted in California as a method of irrigation suitable for washer machines, and uses the pump of the washer machine to pressurize a distribution line with either holes drilled or valves connected, typically letting water out into a mulch basin. To minimize damaging backpressure on the pump, a series of holes / valves are used, ranging from 1/4” to 1” in diameter. To avoid clogging of the holes, at least a 3/8” hole is recommended. According to the Oasis Design calculator about 10 holes is required to avoid overloading the pump / achieving uneven distribution. A mulch basin for a tree is typically about 4‟ in diameter, or 12.6 square feet. The total irrigated area with 10 mulch basins will be 126 square feet. Assuming 4 people in the house, 60 gallons per day is generated. 126 square




feet does exceed the soil requirements as listed in Table 16A-2 for even heavy clay soil. Table 16A-2 defines the maximum amount of water allowable for dispersal—not efficient irrigation. However, assuming an ETo Value of 7” per month (peak summer average across the more heavily populated regions of California), the optimum irrigation area is: Low water use plants 1,451 square feet (c/w L2L efficiency 8%) Medium water use plants 839 square feet (c/w L2L efficiency 15%) It is possible, if washing is done on a daily or every second day, that capillary irrigation effects will assist, however at best this is likely to double the efficiency of L2L up to 30% - maybe 40%. Laundry to Landscape isn't the only option—some graywater dripperlines (e.g. IrriGRAY) can use gravity alone to irrigate at a rate of 1 gallon per minute, per 150 feet of dripperline, covering 700 square feet of garden area with light clay soil. 300 feet of dripperline will therefore cover 1,400 square feet. If the washing machine is run every day, or second day, the irrigation efficiency is about 90%, so much more water is saved. This method does require the use of a surge tank (e.g. a 50 gallon barrel) which is within the Title 16A regulations. However if you wanted to boost the speed of efficient irrigation with a pump, a permit is required. Why did the authorities require a construction permit for a pressurized system? We have received a number of reasons from various authorities: It was considered that as soon as a pump is used, a contractor would be

required, therefore a construction permit is needed. This doesn't make sense to us, because our Australian company‟s experience is that a pump / drip system is far easier to install than the L2L method. If plumbing changes are required (e.g. to access shower graywater), the responsibility is on the licensed plumber to perform work to code.

For personal safety, a GFI should be installed, and as part of the inspection

process, this would be checked. On this basis, any pond pump sold at a hardware / garden centers should also require a construction permit before it is installed.

To avoid any possibility of pressurized backflow of graywater (or

contaminants) entering the potable water supply via a possible cross connection with a potable water irrigation system, a RP backflow must be installed at service entry to the property, and this needs to be checked during the inspection process. On this basis, any irrigation components available at hardware / garden centers should also require a construction permit.

Closing comments for California We understand that changing the code in California was particularly difficult, with many stakeholders having conflicting views on the re-use of graywater. However the code remains too difficult / expensive to achieve compliance for the water savings achieved in many counties. California needs to decide how important water conservation is, and what role it plays in enabling economic growth.

11.2.6 Washington State Rather than repeat the whole code here (it is 15 pages long!), here is the link: Draft Rule Chapter 246-274 Greywater Reuse for Subsurface Irrigation May 17, 2010 As stated in the title, this is a DRAFT rule, that has not been enacted, and (hopefully) will change before implementation. I have paraphrased some of the code in order to reduce space requirements. As in California, “ Nothing in this chapter prohibits the adoption and enforcement of more stringent regulations by the local health jurisdiction”. Light greywater and Dark greywater are defined. Dark greywater may only be used with a Tier 3 treatment system. "Subsurface irrigation" means applying greywater below the surface of the ground directly into the plant root zone. The greywater may be used for subsurface irrigation of plants that produce food but must not come into contact with edible portions of any plant. This is a three tier code. Tier 1: A gravity fed irrigation system, maximum 60 gallons per day. NO pumps. No permit is required. However two separate Tier 1 systems (i.e. a total of 120 gallons per day) can be installed—the local authority may require a permit if two Tier 1 systems are installed.



http://www.doh.wa.gov/ehp/ts/WW/greywater/rule/draft246-274.pdf


Tier 2: A pumped, non treatment graywater system, up to 300 gallons per day. A permit is required: Tier 3: A pumped, graywater treatment system, under 3,500 gallons per day. Tier 1: Gravity system (a) The greywater is light greywater. (b) The total flow of greywater is 60 gallons per day or less. (c) The greywater originates from a single-family residence. (d) The single-family residence is served by either a public sewer system or

an on-site sewage system. (e) The greywater is diverted to the subsurface irrigation system through a

single diversion point. Flows from fixtures located close enough to each other to be diverted through a single diversion point may be combined.

(f) The greywater is delivered through the irrigation system by gravity distribution and no pumps are used to convey the greywater.

(g) The greywater is not stored. (h) The total minimum irrigation area available to receive the greywater is

adequate based on a calculation of: (i) the estimated volume of greywater; (ii) the evapotranspiration rate in inches per week for the geographic

area of the state where the landscape or garden is located; and (iii) the water requirements of the plants, known as a plant factor. A

“Greywater System Checklist and Irrigation Area Estimation Tool” is available from the Washington State Department of Health‟s website, [website address to be inserted here].

(i) The system is covered by at least four inches of appropriate material which may include suitable soil or other material such as mulch, humus, or compost. If material other than suitable soil is used, the irrigation field is augmented periodically as needed to maintain adequate cover during the growing season.

(j) The homeowner ensures that the system is properly operated and maintained.

(k) The homeowner maintains a record of the system that shows the location of the system, identifies the fixture or fixtures that are the source of the greywater, describes the system design and the system‟s maintenance requirements, and includes the calculation of the total irrigation area required under subsection (h) of this section.

(l) The homeowner may direct greywater to separate irrigation fields so long as the total flow of greywater to all fields combined does not exceed 60 gallons per day.

This the first code I have seen that requires an evapotranspiration rate & plant factor calculation , and that even a simple gravity system must irrigate a correctly sized area. What is doesn't do is specify (yet) what the required minimum irrigation efficiency is. Later in the code, Tier 2 & 3 systems assume a 90% irrigation efficiency.

Tier 2: Pumped untreated graywater, under 300 gallons per day A permit is required, unless a qualified professional designs a Tier 2

system for a single family residence. Must be installed by a qualified professional, except the local health

official may allow a resident owner of a single-family residence (not adjacent to a marine shoreline) to design a system, or the health officer may design the system if the office performs the soil and site evaluation.

“Qualified professional” means an on-site sewage treatment system

designer licensed under chapter 18.210 RCW or a professional engineer licensed under chapter 18.43 RCW who is knowledgeable in irrigation system design.

Irrigation rates shall be calculated by using the following equation:

Estimated Water Use in gallons per day = Irrigation Area x Evapotranspiration x Plant Factor x 0.62 divided by Irrigation Efficiency x 31 days per month, where:

Irrigation Area equals the number of square feet to be irrigated; Evapotranspiration equals the average of either May through September Monthly Irrigation Requirements, in inches, as determined by the Washington State University, State of Washington Irrigation Guide (WIG), 1985 (as amended 1990; 1992 for select western Washington crops), or monthly averages for systems that adjust application rates by the month or based on actual conditions; Plant Factor equals 0 to 0.3 for low water use plants; 0.4 to 0.6 for average water use plants; and 0.7 to 1.0 for high water use plants; and Irrigation Efficiency equals 0.9 (if this looks familiar, it is the same formula that we use in this guide. The formula was supplied by us to a member of the committee)

Application of the greywater to the plants is even throughout the irrigation

field. This is typically achieved through pressure distribution. The subsurface irrigation components of the greywater irrigation system

must be installed a minimum of six inches deep and no deeper than 12 inches below the finished grade. The six inch cover layer must consist of four inches of suitable soil and two inches of mulch.



(This is bad. Why must the dripperlines be covered with 4 inches of soil? The most efficient location for dripperlines is at the surface with a covering of mulch. The 90% irrigation efficiency factor only applies to sub mulch irrigation, because capillary irrigation effects are stronger in the top 2-3” of soil. Placing dripperline 4” under soil will automatically increase dripperline length by about 300%, labor by 400%, and owner maintenance by 100% due to the extra filtration required.)

To get a permit: You need a soil and site evaluation by a qualified professional or local health

office. You may be allowed to perform your own evaluation is not on a marine shoreline, if the local health office agrees.

The person evaluating the soil and site shall: (a) provide a report to the local health officer that includes:

a soil map showing the soils within the project site. The person evaluating the soils must ensure that the soil types of the site are properly identified, correctly used in the hydrologic analysis, and will provide suitable soil capable of supporting healthy plant life. If the original, undisturbed soil will be augmented with additional soil, include a description of the additional soil, how it will be tilled into the original soil, and how the resulting soil will meet the requirements of WAC 246-274-415(1)

use the soil names and particle size limits of the United States Department of Agriculture Natural Resources Conservation Service classification system; and (c) determine texture, structure, compaction, and soil characteristics and classify the soil as in WAC 246-274-415, Table II.

describe the drainage characteristics of the site and those areas

immediately adjacent to the site that contain characteristics impacting the design; (iii) the existence of designated flood plains and other areas identified in the local management plan required in WAC 246-272A-0015; and (iv) the location of existing features affecting system placement, including the items requiring setback, identified in WAC 246-274-405, Table 1, and other features such as: 1. surface water and stormwater infiltration areas; 2. abandoned wells; 3. outcrops of bedrock and restrictive layers; 4. driveways, parking areas, and other impervious surfaces; 5. the on-site sewage system serving the building, if any; and 6. underground utilities.

Prior to beginning the construction of a Tier 2 or Tier 3 greywater irrigation

system, a person proposing the installation of such a system must provide information to, and obtain a permit to install from, the local health officer. The information provided shall include: (a) the following general information: (i) name and address of the property owner; (ii) parcel number and if available, the site address; (iii) identification of the public sewer system or on-site sewage system serving the property; (iv) size of the parcel; (v) name,

signature, and stamp, if applicable, of the person responsible for designing the system; (vi) date of application; and (vii) name and signature of the owner or the owner's authorized agent. (b) the soil and site evaluation specified under WAC 246-274-420; (c) a dimensioned site plan of the proposed irrigation field, including: (i) general topography and/or slope; (ii) drainage characteristics (iii) the location of existing and proposed encumbrances affecting system placement, including legal access documents, if any component of the system is not on the lot where the greywater is generated. (d) location, type, and size of the irrigation system components; (e) flow rate in gallons per minute, application rates in inches per hour, and design operating pressure per square inch for each zone; (f) source of greywater (fixtures) and the location of the diversion valve; and (g) any additional information deemed necessary by the local health officer.

Installation and Site inspection Only a person approved by the local health office may construct and install a Tier 2 or Tier 3 system. The approved installer must be on the site at all times during the excavation and construction of the system. The local health office shall either inspect the system before cover, or allow the person who designed the system to inspect, but only if the designer is not also the installer. Discussion Tier 1 I do not see how either branched drain, or Laundry to Landscape (L2L) systems can be installed while having any regard for evapotranspiration rates and plant types. According to the Oasis Design calculator about 10 holes is required to avoid overloading the pump / achieving uneven distribution for a L2L. A mulch basin for a tree is typically about 4’ in diameter, or 12.6 square feet. The total irrigated area with 10 mulch basins will be 126 square feet. However, assuming an ETo Value of 5” per month (summer average across many parts of Washington State), the optimum irrigation area is: Low water use plants 2,256 square feet (c/w L2L efficiency 5%) Medium water use plants 1,304 square feet (c/w L2L efficiency 10%) High water use plants 903 square feet (c/w L2L efficiency 14%) It is possible, if washing is done on a daily or every second day, that capillary irrigation effects will assist, however at best this is likely to double the efficiency.




Branched drain efficiency is worse, as no more than 6 outlets would be installed for a system of this size. Laundry to Landscape isn't the only option—some graywater dripperlines (e.g. IrriGRAY) can use gravity alone to irrigate at a rate of 1 gallon per minute, per 150 feet of dripperline, covering 700 square feet of garden area with light clay soil. 300 feet of dripperline will therefore cover 1,400 square feet. If the washing machine is run every day, or second day, the irrigation efficiency is about 90%, so much more water is saved. This method does require the use of a surge tank (e.g. a 50 gallon barrel) . Tier 2 Basically, the permit process is onerous. A full house greywater collection, pumping and irrigation system costs about $2,000 installed in Arizona, New Mexico and Texas, with little ongoing maintenance. The same style of system will cost at least $4,000 under this proposed code, and require much more ongoing maintenance (due to the extra filtration required for in soil dripperlines). The critical comparison between Tier 1 and Tier 2 (apart from permitting costs) is Tier 1 only requires 4” of mulch , whereas pressurized dripperline must be covered by at least 4” of soil and 2” of mulch. This simply doesn't make sense. Supplying 6 gallons a day into a 12 square foot mulch basin (L2L or branched drain) is much more likely to produce surface runoff than applying water via dripperline on the surface at a rate of 0.046 gallons per day per square foot.

11.2.7 Utah Rule R317-401. Graywater Systems At about 5 pages in length, the code is relatively straightforward. Unfortunately it would appear to be focussed on disposal, rather than beneficial use of the graywater. Here are the key points: Sub surface irrigation dripperlines must buried at a minimum depth of six

inches. Drip feeder lines can be polyethylene or flexible PVC tubing and shall be covered to a minimum depth of six inches.

Agency shall issue a renewable operating permit at a frequency not

exceeding five years with inspection of the permitted systems before renewal; or, inspect annually the greater of 20 per cent of all installed

system or the minimum of ten installed systems Designer certified at Level 3, in accordance with the requirements of

R317-11, shall design the graywater systems. at least 250 gallons in volumetric capacity to provide settling of solids,

accumulation of sludge and scum unless justified with a mass balance of inflow and outflow and type of distribution for irrigation;

The local health department may require the following information with

or in the plot plan before a permit is issued for a graywater system:

(i) plot plan drawn to scale, completely dimensioned, showing lot lines and structures, direction and slope of the ground, location of all present or proposed retaining walls, drainage channels, water supply lines, wells, paved areas and structures on the plot, other utilities, easements, number of bedrooms and plumbing fixtures plan in each structure, location of onsite wastewater system and replacement area of the onsite wastewater system, or building sewer connecting to a public sewer, and location of the proposed graywater system;

(ii) a log of soil formations and identification of the maximum anticipated ground water level as determined by the minimum of one test hole, dug in close proximity, two feet below the bottom of the subsurface irrigation field or drip irrigation area together with a statement of types of soil based on soil classification at the proposed site. Soil and groundwater evaluations will be conducted by professionals fulfilling the requirements of R317-11;

Discussion: The key issue with this code (for gardening and water conservation purposes) as having to place the dripperlines at least 6” below surface level. Because of this, irrigation efficiency decreases substantially. In addition more dripperline must be used ($$) and higher levels of filtration are required. The requirement for 250 gallons of storage capacity is not a significant issue, because if sufficient dripperline is installed to irrigate at peak flow rate (mass balance of inflow and outflow).

11.2.8 North Carolina The session law provides interim standards for use of gray water for hand-watering inedible plants that will sunset when rules adopted by the Commission



http://www.rules.utah.gov/publicat/code/r317/r317-401.htm

for Health Services go into effect . This is quite a strange law. As part of an emergency bill, untreated graywater reuse is allowed but only using buckets / watering cans or other handheld containers. House Bill 2499 (2008 Drought Bill) SECTION 14.(a) For purposes of this section, "gray water" means wastewater removed from household wash basins, bathtubs, and showers. SECTION 14.(b) The Commission for Health Services shall adopt rules to authorize the use of gray water during periods of drought to hand water trees, shrubs, and inedible plants on single-family residential property. The rules shall encourage the use of gray water as provided in this section while protecting public health, safety, welfare, and the environment. In developing the rules, the Commission shall review the provisions set out in subsection (c) of this section. SECTION 14.(c) Notwithstanding G.S. 130A-335(a), untreated gray water may be used in periods of drought to hand water trees, shrubs, and inedible plants on single-family residential property under the following conditions: (1) Gray water shall be applied as soon as practicable. Untreated gray water

should not be stored for later use. (2) Gray water containing hazardous chemicals including, but not limited to,

residue from solvents shall not be used. (3) Use of untreated gray water is restricted to the residential property where

the gray water originates. Untreated gray water shall not be allowed to run off onto adjoining property, roadways, or into drainage features such as ditches and storm drains.

(4) Untreated gray water shall be applied using buckets, watering cans, or other handheld containers. Gray water may not be used in an irrigation system unless the gray water has been treated in accordance with standards set out in the State Plumbing Code.

(5) Gray water shall not be applied closer than 100 feet to surface waters or a water supply well.

11.2.9 Oregon On June 12, 2009, Governor Ted Kulongoski signed into law House Bill 2080, which legalizes the use of graywater for beneficial uses. The bill establishes that a person may not construct, install, or operate a graywater reuse and disposal

system without a permit from the Oregon Department of Environmental Quality (DEQ). The bill further directs the Environmental Quality Commission (EQC) to adopt rules for graywater permitting. The Graywater Advisory Committee will develop and provide DEQ with recommendations on the treatment, disposal, and reuse of graywater. DEQ will consider these recommendations when writing the new graywater rules. The committee is scheduled to report to the DEQ by the end of 2010.

11.2.10 Other States While some states require graywater to be sent directly to sewer or septic, other states may allow beneficial re-use under Innovative Application rules. Check with your local authorities. Do you know something I don’t know? Drop me a line: [email protected]



http://www.ncwater.org/drought/

http://www.deq.state.or.us/wq/reuse/gwadvisory.htm

Back to Guide Contents


Water saving products and systems

Product Contents 1. Water Saving Products & Systems

1.1 IrriGRAY dripperline 1.2 IrriGRAY graywater (gravity) kit 1.3 IrriGRAY graywater (pressurized) kit 1.4 IrriGRAY pumping systems

2. Rainwater Harvesting Products & Systems

2.1 IrriGRAY rainwater (gravity) kit 2.2 Rain Barrel Pump and Hose Kit

Best Home Water Savers is a Division of Just Water Savers USA Inc.

Just Water Savers USA, a family owned company with facilities in AZ, OH and OR, is the designer and manufacturer of IrriGRAY systems and components.

Our history is out of Australia, with 10+ years experience manufacturing, selling, installing and support of over 5,000+ graywater systems.

We know what is required to save water (and money) long term.

It is not about bells and whistles.

It is about producing the most basic systems, using high quality components that simply work, every year, with minimal maintenance.

By concentrating on individual stages of graywater re-use (collect, pump, filter and irrigate) solutions can be combined to suit each home, without costing more.

Many people believe graywater / rainwater irrigation is expensive, or difficult - and this can be the case with over-engineered systems that are unnecessarily complicated, or suit only one style of house.

This no longer has to be the case. For most houses, new or old, an entire collection, pumping and irrigation system can be bought for around $1,000.

Gravity based irrigation systems, can be bought for around $200.

In many states the payback period (including installation) can be as little as 1 year (gravity system), or 2-3 years (pumped system), and the homeowner is rewarded with significant savings every year beyond.

This means that in addition to helping the environment, homeowners can enjoy green gardens around their home while saving money, year after year..

Dealers

We encourage our customers to check for local dealers and enquire about our products from them directly.

They have received training from us and can provide guidance to suit your area (e.g. rainfall patterns, local codes and regulations, soil type and climate considerations). They are also likely to provide cheaper pricing (overall) as a result of bulk shipping savings.

www.besthomewatersavers.com

Just Water Savers USA Inc. provides this shopping site as a convenience for customers who do not have a dealer nearby, and wish to purchase from us directly. This site is also how our dealers and resellers order stock from us, so you can be confident that the stock you see in store is exactly the same as on line.

http://www.besthomewatersavers.com/pages/Your-local-Dealer.html

http://www.besthomewatersavers.com/pages/Your-local-Dealer.html

http://www.besthomewatersavers.com

IrriGRAY is the only complete dripperline irrigation package specifically designed to be used in conjunction with Graywater Diversion Devices. With over 6 years use, in many thousands of installations in the tough Australian climate, IrriGRAY is proven to deliver graywater efficiently and evenly across the entire irrigation area. IrriGRAY is now manufactured in the US, in standard US 16mm irrigation tube size. Advantages of choosing IrriGRAY

Specifically designed drippers that resist clogging

Over 90% irrigation efficiency, compared with 20% - 40% efficiency of branched drain and laundry to landscape methods.

Minimum filtration required is a low 40 Mesh (or 400 Micron)

Significant material and labor cost savings compared to any other graywater irrigation system

Eliminates the need for large graywater pumping containers

Minimal maintenance & servicing

Easy and quick to install, providing significant cost / labor savings compared to any other method.

How IrriGRAY works IrriGRAY dripperlines are laid on the soil surface,

covered by 2" of mulch Each drip emitter has a built-in filter Dripperlines are connected to the main 3/4" poly tube

supply network

Ideally, graywater is pumped into the supply network after passing through a 40 Mesh (400 Micron) filter.

IrriGRAY can also be used without a pump, for graywater and/or rainwater. This is particularly useful for irrigating with washing machine water in California, where using a pump requires a construction permit.

Connecting IrriGRAY dripperline to LDPE supply tube

More Information:

www.besthomewatersavers.com. www.irrigray.com

Back to Product Contents


Inlet Pressure

Nominal flow

Max Lateral Line Length

3' 0.7 GPH 52'

6' 0.9 GPH 56'

15' 1.4 GPH 56'

30' 1.9 GPH 59'

Soil Type Separation

Gravel and Sands 1.8 Feet

Sandy Loams 1.8 Feet

Loams 2.4 Feet

Clay Loams 2.7 Feet

Light Clays 3.0 Feet

Medium to Heavy Clays

4.5 Feet

Specifications Dripper flow rate 2 GPH Dripper spacing 12" Pressure range 2 - 45 PSI Tubing diameter 0.540"

I.D. 16mm O.D. Tubing color black Coil Length 150' UV resistant Tubing Material - Low Density

Polyethylene (LPDE) Features & Benefits Superior TurboNet flow regime

Largest filtration area and cross section flow path on the market. Dripper is 2.2" in length. Increases clog resistance from source

The position of the filter to the dripper draws cleaner water from the center of the flow path, reducing the risk of clogging

2 Minute takeoff connections Video (click on Icon)

Products 1.1 IrriGRAY graywater dripperline

http://www.besthomewatersavers.com/products/IrriGRAY-Dripperline-coil-%28150%27%29.html

http://www.irrigray.com

http://www.youtube.com/watch?v=DCErrhPx6tE

IrriGRAY Kit: Graywater by gravity

Specifically designed for Graywater Irrigation, the low filtration requirements and even, fast flow rate make it the ideal choice for gravity irrigation of graywater. IrriGRAY is the only dripperline requiring minimal filtration (40 mesh / 400 micron) and providing 0.4 GPH flow per emitter with just 12” of head pressure. Supplied with 150‟ of IrriGRAY dripperline, this kit will irrigate at a flow rate of 1 gallon per minute. Additional coils can be added. Imagine irrigating your garden with water from your washing machine, evenly and automatically - no buckets or watering cans required! With over 90% irrigation efficiency, IrriGRAY saves 3 times or more the amount of water than branched drain or Laundry to Landscape systems at a similar material cost but requiring much less labour (install in less than 1/2 hour).

How IrriGRAY works

IrriGRAY dripperlines are laid on the soil surface, covered by 2" of mulch

Dripperlines are connected to the main 3/4" poly tube supply network

Connect the supply line, valve and primary filter to the base of the barrel / cistern.

Advantages of choosing IrriGRAY

Automatic even watering of your garden at 90% efficiency (3 x better than branched drain or Laundry to Landscape)

Easy installation, install in 1/2 hour, instead of many hours effort required with branched drain or L2L

Emitters are pre-installed, simply lay the dripperline and supply line in the garden and connect to your barrel

Low maintenance, high capacity, easy to clean filter.

NO PERMIT REQUIRED IN CALFORNIA

Easy Installation


Flow rates of IrriGRAY network (gpm = gallons per minute)

Time to irrigate minutes with 150'

Head Pressure Total length IrriGRAY dripperline

Top load washer

Front load washer

Feet 100’ 150’ 200’ 300’ (40 Gallons) (15 Gallons)

1’ 0.7 gpm 1.0 gpm 1.3 gpm 2.0 gpm 40 mins 15 mins



These diagrams illustrate the amount of head pressure obtained from a barrel collecting graywater. Minimum head pressure is obtained when the barrel is empty. Extra head pressure is generated when the barrel contains water.

Flat ground, near floor level Placing a barrel sideways, on a barrel stand will provide more head than a barrel standing directly on the ground. This is only important if a faster flow rate than 1.0 GPM is required (with 150’ of IrriGRAY). Ground sloping downwards, away from the house Little flow rate benefit is achieved by laying a barrel on its side if the irrigation area is down hill from the barrel location. Ensure the barrel is placed on a firm, level surface to avoid risk of tipping.

Min. head

Extra head

Extra head

Min. head

Kit includes a manual valve and a large 40 mesh filter (small filter shown). In most cases the large filter will need cleaning after 1,000 gallons of washing machine water. Cleaning takes no longer than 2 minutes.

4 Minute Installation Video (click on Icon)


A full pictorial installation guide is available online.

More Information Online at www.besthomewatersavers.com

Products 1.2 IrriGRAY gravity kit Back to Product Contents

http://www.youtube.com/watch?v=_hB6U62oAHI


http://www.besthomewatersavers.com/products/IrriGRAY-Kit-%252d-Graywater-by-gravity.html

IrriGRAY Kit: Graywater (pressurized)

IrriGRAY is the only complete d r ippe r l ine i r r iga t i on package specifically designed for graywater irrigation. With over 5 years use, in many thousands of installations in the tough Australian climate, IrriGRAY is proven to deliver graywater efficiently and evenly across the entire irrigation area. IrriGRAY is so popular in Australia, it now has over 90% of the residential graywater dripperline market. It is now also manufactured here in the USA. IrriGRAY is suitable for both DIY and professional installation. With over 90% irrigation efficiency, IrriGRAY saves 3 times the amount of water than branched drain or Laundry to Landscape systems at a similar material cost but requiring much less labour. How IrriGRAY works IrriGRAY dripperlines are laid on the soil surface, covered by 2" of mulch

Each drip emitter has a built-in filter


Graywater is pumped into the supply network after passing through a 40 Mesh (400 Micron) filter

The IrriGRAY filter typically requires cleaning once per month (approx 2,000 gallons), and takes less than two minutes to clean. Additional filters can be added in parallel to increase capacity / decrease cleaning frequency.

Advantages of choosing IrriGRAY Superior TurboNet flow regime, by Netafim

Largest filtration area and cross section flow path on the market. Dripper is 2.2" in length. Increases clog resistance from source

The position of the filter to the dripper draws cleaner water from the center of the flow path, reducing the risk of clogging

Minimum filtration required is a low 40 Mesh (or 400 Micron)

Significant material and labor cost savings compared to any other graywater irrigation system


Products 1.3 IrriGRAY kit (pressurized)

Fast 2.0 GPH emitters eliminate the need for large graywater pumping containers

Minimal maintenance & servicing

Easy to install

Irrigate the garden bed, Not the

plants!

With a 2.0 GPH emitter flow rate, IrriGRAY delivers graywater quickly and evenly across the entire garden space.

Because the garden can be irrigated with graywater every day, the irrigation system can rely on capillary action within the soil to create even moisture levels across all garden areas.

The key concept is "water the garden bed, not the plants".

There is sufficient moisture in the soil for plants to take what they need, without the risk of root rot.

The amount of graywater dripperline required is 70% less than traditional irrigation dripperline, providing significant savings in material and installation.

Dripperline Separation

Soil Type Separation

Gravel and Sands 1.8 Feet

Sandy Loams 1.8 Feet

Loams 2.4 Feet

Clay Loams 2.7 Feet

Light Clays 3.0 Feet

Medium to Heavy Clays 4.5 Feet

The standard kit includes 300‟ of IrriGRAY dripperline, and 150‟ of 3/4” LDPE supply tube.

Additional coils and fittings are available separately.

The geofabric filter is installed in a convenient location after the graywater pumping device.

3/4” tube (LDPE) is then used to create a supply network around the property (dark lines). IrriGRAY dripperline is then connected to the supply network, resulting in even irrigation across the entire property (purple lines).

Advantages (continued)

More Information:

2 Minute takeoff connections Video click on Icon)



The directors and managers of Just Water Savers USA Inc have extensive experience manufacturing and installing thousands of graywater diversion systems in Australia. Our USA pumping systems use the same core design principles as our Australian systems (certified under the Australian Watermark Standard), but are manufactured here in the USA using high quality pumps and fittings matching USA plumbing and irrigation standards. The following features are standard in all of our pumping systems:

Quality 660W Pump as standard They key to long term effectiveness and reliability is using a powerful quality pump to ensure fast irrigation, without having to work the pump hard. The 660W pump uses 440W when in operation, and only costs about 50 cents per month to run for a typical family of 4. Less powerful pumps work harder (shortening the service life), and can cause loss of graywater to overflow. The 660W pump also allows the use of 3/4” supply tube, instead of 1” tube required with lower powered systems. 3/4” supply tube carries about 1/2 the volume of water compared to 1” tubing. 1” tubing therefore requires much more graywater to fill it before the dripperlines are pressurized, typically resulting in uneven irrigation across the garden. A 2 year manufacturers warranty is included with each pumping system.

Flexible installation options Want more than 1 inlet? Need to use 3” plumbing instead of 2”? Have a stub out 48” below ground, or perhaps the stub out is 36” above ground? Our range of systems cope with just about any site difficulties, and every house is different! In addition to manufacturing, our experience includes thousands of installations across a wide range of housing styles. Our systems are the most flexible on the market, saving you money in time, labor and materials. Filtration AFTER the pump This not only saves more graywater (see last page), but provides far greater installation flexibility. Need to place the pumping unit in the crawl space, or 48” below ground level? No problem—the filter can be installed in any convenient location before the irrigation tubing starts. Self cleaning system The internal flushing tube (patent pending) ensures that graywater sludge and particles do not collect inside the basin over time. While we recommend an annual inspection of the unit, regular cleaning of the basin is NOT required— a fantastic benefit for crawl space and deep in ground installations. No electronic controllers or sensors Our systems use a single float switch that is reliable and simply can not hang or become caught. This is far more reliable than systems using small sensors and electronic controllers that require regular servicing, and are prone to damage / interference from GFIs.


Products 1.4 IrriGRAY pumping systems

Customer Testimonial

My name is Rick Stephenson. I am the director of Construction for Pepper Viner Homes in Tucson Arizona. At Pepper Viner Homes, we have been engaged in research and the building of green energy efficient homes for years now. The company has always attempted to stay out in front of the upcoming trends and best practices towards common sense building... ..Here in Tucson Arizona, conserving water has always been on the forefront and is now becoming even more of a factor as we continue to grow... . ...we successfully installed two complete systems in a model home park, Sunnyside Pointe. The systems are working beautifully and are actually being used by the City of Tucson as a “Water Harvest Demonstration Site” for the general public. .. ... Pepper Viner Homes will continue to use Just Water Savers USA for all of our future Graywater needs. .. ...Adding to the value of this system, we know we can install the complete system inexpensively and it will be very simple to maintain. As I mentioned earlier, the system is very flexible and can be converted to both shallow and deep public sewer connections and is a slam dunk for septic systems! (click here for the full text).

One each of the IrriGRAY pumping systems were installed in two new homes in Tucson AZ. These were combined with IrriGRAY irrigation kits . enabling far more garden coverage than other systems.


Our range of pumping systems is listed on the next page

http://www.besthomewatersavers.com/products/IrriGRAY-18%22-x-30%22-inground-pumping-systen.html

IrriGRAY 18" x 22" in ground pumping system 18" (Diameter) x 22" (depth) HDPE black container, lid secured by screws / bolts. Suitable for in-ground installations.

Click here for more information.

IrriGRAY 18" x 30" in ground pumping system 18" (Diameter) x 30" (depth) HDPE black container, lid secured by screws / bolts. Suitable for in-ground installations. Click here for more information.

IG 183012 - IrriGRAY 18" x 12" extension 18" (Diameter) x 12" (height) extension collar, to extend depth of the 18" x 30" container. Screws / bolts included. Note a maximum of 2 extension collars may be fitted to a 18" x 30" container. This collar is not suitable for the 18" x 22", or 20 gallon container. Click here for more information.

IG 20 - 20 gallon above ground / partial in-ground collection pumping system 20 gallon HDPE yellow container, with opaque white lid. Suitable for on ground and partially in-ground installations. Lockable lid ring.

Click here for more information.

IG 12 - 12” square by 14.5” deep above ground / partial in-ground collection pumping system 20 gallon HDPE yellow container, with opaque white lid. Suitable for on ground and partially in-ground installations. Lockable lid ring.

Coming soon!


Pump Specification:

660W Ecovort 520A dirty water pump (made

in Italy), up to 28’ head

2 year manufacturer’s warranty

Energy efficient motor with built-in overload

protection and stainless steel shaft

Environmentally safe, oil-free

Ceramic shaft sleeve for long life and sand

resistance

Perfect cooling allowing running of pump even

if partially submerged

Inlet and Overflow Location

Inlets and Overflow are not predrilled,

providing complete flexibility to change the plumbing design to best suit the site situation.

Each pumping system includes: Ecovort 520A 650W dirty water pump with 2 year manufacturers

warranty. Pump float modified for lower turn on / turn off water levels. Pump is pre installed, with fittings for connection of 3/4" LDPE poly tube included.

Internal plumbing system, including automatic container cleaning components.

2 x 2" seals, for connecting 1 inlet and 1 overflow schedule 40 2" ABS or PVC pipe. Alternative seal sizes available (e.g. 3”)

Lower drain assembly (1 valve at base and extra valve situated above. Style and location varies according to pumping model. Full port drain available for jurisdictions requiring complete gravity drainage for inspection.

Options: Additional 2” & 3” seals are available.

Each system is can be fitted with a standard potable water float

valve, for makeup water supply connection. Video 18” x 30” basin, with two 18” x 12” extension collars, for house with

graywater stub out 42” below surface level. Click on the YouTube icon to view.

Back to Product Contents Products 1.4 IrriGRAY pumping systems

http://www.besthomewatersavers.com/products/IrriGRAY-18%22-x-22%22-inground-pumping-system.html

http://www.besthomewatersavers.com/products/IrriGRAY-18%22-x-30%22-inground-pumping-systen.html

http://www.besthomewatersavers.com/products/IrriGRAY-18%22-%28diameter%29-x-12%22-%28height%29-collar-extension.html

http://www.besthomewatersavers.com/products/IrriGRAY-20-Gallon-above-ground-%7B47%7D-partial-inground-pumping-system.html

http://www.youtube.com/watch?v=FS1mEXRcrPw

IrriGRAY Kit: Rainwater by gravity

Although IrriGRAY dripperline is designed for graywater use, its low filtration requirements and even, fast flow rate make it the ideal choice for gravity irrigation of collected

rainwater.

IrriGRAY is the only dripperline requiring minimal filtration (40 mesh / 400 micron) and providing 0.4 GPH flow per emitter with just 12” of head pressure.

Supplied with 150‟ of IrriGRAY dripperline and 150‟ of 3/4” supply line, this kit will irrigate at a flow rate of 1 gallon per minute.

Additional coils can be added.

Imagine irrigating your garden with water from your rain barrel or cistern, evenly and automatically - no buckets or watering cans required!

How IrriGRAY works

IrriGRAY dripperlines are laid on the soil surface, covered by 2" of mulch


Connect the supply line, valve and primary filter to the base of the barrel / cistern.

Advantages of choosing IrriGRAY

Automatic even watering of your garden at 90% efficiency (3 x better than branched drain or Laundry to Landscape)

Easy installation, install in 1/2 hour, instead of many hours effort required with branched drain or L2L

Emitters are pre-installed, simply lay the dripperline and supply line in the garden and connect to your barrel

Low maintenance, high capacity, easy to clean filter.

NO PERMIT REQUIRED IN CALFORNIA


These diagrams illustrate the amount of head pressure obtained from a barrel collecting rainwater. Minimum head pressure is obtained when the barrel is empty. Extra head pressure is generated when the barrel contains water.

Flat ground, near floor level Placing a barrel sideways, on a barrel stand will provide more head than a barrel standing directly on the ground. This is only important if a faster flow rate than 1.0 GPM is required (with 150’ of IrriGRAY). Ground sloping downwards, away from the house Little flow rate benefit is achieved by laying a barrel on its side if the irrigation area is down hill from the barrel location. Ensure the barrel is placed on a firm, level surface to avoid risk of tipping.

Min. head

Extra head

Extra head

Min. head

Kit includes a manual valve and a large 40 mesh filter (small filter shown). In most cases the filter will only require a clean once per year (rainwater).

4 Minute Installation Video (click on Icon) small filter shown


A full pictorial installation guide is available online.

More Information Online at www.besthomewatersavers.com

Products 2.1 Rainwater Harvesting: IrriGRAY Rainwater kit

Flow rates of IrriGRAY network (gpm = gallons per minute)

Head Pressure Total length IrriGRAY dripperline

Feet 100’ 150’ 200’ 300’

1’ 0.7 gpm 1.0 gpm 1.3 gpm 2.0 gpm

3’ 1.1 gpm 1.7 gpm 2.3 gpm 3.4 gpm

6’ 1.5 gpm 2.2 gpm 3.0 gpm 4.5 gpm

Easy Installation




http://www.besthomewatersavers.com/products/IrriGRAY-Kit-%252d-Rainwater-by-Gravity.html

Rain Barrel: Pump & Hose Kit

Barrels are great for storing water, but how do you get the water to where you really need it? Our unique (US patent pending) internal pump and plumbing outlet assembly gives you the power to get the water where you need it. You can even close the nozzle while the pump is running, without damaging the pump. This lets you conserve precious water by turning off your hose while you walk from one area of the garden to another. Simple Installation: Screw the main outlet assembly (vertical tube) onto the

pump outlet, Lift the pump into your barrel, Mark the required location for the outlet hole, Drill a hole with a 1" drill or hole saw, Push the male thread of the elbow through the hole, and Attach the outside elbow and connect the hose. This pump & hose kit can also be used for graywater collection and pumping. Note aeration of graywater is permitted in Wyoming. Features: 1 HP submersible dirty water vortex pump Suitable for rainwater and graywater Plenty of pressure through up to 100' of hose. This

pump creates a jet / spray of 25‟ from the nozzle

The pump is provided with a 1 year limited warranty.

Volume relief tube allows water to circulate inside the barrel You can close the hose nozzle while the pump is still

running, without damaging the pump

Keeps the barrel clean by constantly stirring any solids in the water.

Anti-siphon air admitter Air admittance prevents water loss via siphoning

50’ of highest quality 3/4" kink resistant hose

Not your average hose! Supplied with a limited lifetime warranty.

High quality adjustable brass nozzle

The cover is removable, so is easily cleaned if foreign matter clogs the outlet.

Dimensions:

Through barrel hole; approx 30” above internal base of barrel (Other heights are available to suit different barrel styles).

A hole 10” x 8” is required in the top of the barrel to insert the pump (or use a barrel with a removable cover).


Products 2.2 Rainwater Harvesting: Pump and Hose Kit

DIY Installation Children and open water containers can be a deadly combination. Ensure your method of storing water is anchored safely and child proof. Note that some mobile trash cans are not suitable for storing water. The example we have shown has a strong and thick HDPE wall structure.

More Information

(Including pictorial installation guide) Online at www.besthomewatersavers.com

Installation and Operation Video (click on icon)


http://www.besthomewatersavers.com/products/Rain-Barrel-Pump-and-Hose-Kit.html

http://www.youtube.com/watch?v=1ITqXa1tihw

Resources This section will be constantly updated. Whenever conducting your own research on the internet, keep in mind the irrigation method used to disperse the graywater. Many studies have concentrated on disposal, rather than beneficial re-use. Because optimised beneficial re-use typically irrigates an area 10 times that of a disposal field, or 4 times that of a branched drain / laundry to landscape system, the effects of leaching of contaminants via natural rainfall are far greater. In soil bacterial treatment is also far more effective because of the low dosage application rates with an efficient graywater irrigation system.

Graywater Codes (U.S.) Wyoming

New Mexico

Texas

Arizona

California

Washington State

Utah

North Carolina

Oregon

Australian National Greywater Guide Australian Government; National Water Commission(2008) : Urban Greywater Design and Installation Handbook

Sustaining Garden in Dry Times A comprehensive yet easy to read brochure from the Victorian State Government, Australia.

Graywater Studies (U.S.) Preliminary comments on the use of graywater for vegetables, Penn State horticulturists (May 2010) U.S. Water news Online (Oct 2005) Gray water from laundry produces green grass, Description of the outcome of testing conducted by a University of Arizona (Yuma) vegetable specialist.

Long term Effects of Landscape Irrigation using Household Graywater—Literature Review and Synthesis, Colorado State University 2006

Massachusetts Department of Environmental Protection, Bureau of Resource Protection (December 2002), Greywater Characterization and treatment efficiency,

Monitoring Graywater Use: Three Case Studies in California An older study (1999), using old irrigation techniques, but worth a look.

Graywater Studies (Australia) Reuse potential of laundry greywater for irrigation based on growth, water and nutrient

use of tomato

R.K. Misra*, J.H. Patel and V.R. Baxi Faculty of Engineering and Surveying, Australian Centre for Sustainable Catchments and CRC for Irrigation Futures, University of Southern Queensland, Toowoomba, Queensland 4350, Australia (2010)

Domestic Water Use Study, Perth Australia 1998-2001, Michael L0h, Peter Coghlan 2003 A comprehensive study of water use based on demographics and seasonal influences, in a water challenged environment.

Water Conservation Vs. Water Price

U.S. Urban residents cut water usage, Utilities are forced to raise prices Brett Walton, Circle of Blue water news April 2010

The price of water: a comparison of water rates, usage in 30 U.S. Cities, Brett Walton, Circle of Blue water news April 2010

Water use within Households

Residential Water Usage comparison (Tucson) Tucson Water

Water Use in Southern Nevada Southern Nevada Water Authority

Landscape irrigation requirements

California Irrigation Management Information System (CMIS) Et Overview (including links to ETo zone maps)

Electricity consumption, pressurized graywater systems USA Census 2007 electric energy by class of service and state

USA End-Use Consumption of Electricity 2001

Robert Kourik Drip Irrigation for Every Landscape and All Climates - 2nd Edition Metamorphic Press (2009)

Roots Demystified Publisher: Metamorphic Press (2008),

Plumbing Requirements

Irrigation Systems & Backflow Prevention Requirements Tucson Water

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Graywater irrigation pumping system Connecting IrriGRAY dripperline to poly supply tube using takeoff fittings Rainwater irrigation using IrriGRAY dripperline and gravity Rain barrel pump and hose kit, installation and use Branched drain irrigation system, installation overview (Tucson AZ)

Resources

http://deq.state.wy.us/wqd/www/Permitting/Downloads/GWPolicy.pdf


http://www.tceq.state.tx.us/assets/public/legal/rules/rules/pdflib/210f.pdf

http://www.azsos.gov/public_services/title_18/18-09.pdf



http://www.rules.utah.gov/publicat/code/r317/r317-401.htm

http://www.ncwater.org/drought/

http://www.deq.state.or.us/wq/reuse/gwadvisory.htm



http://www.ourwater.vic.gov.au/__data/assets/pdf_file/0009/2322/Sustaining_Gardens_brochure.pdf

http://www.sciencecentric.com/news/10050613-roots-meshed-waste-materials-could-clean-dirty-water.html

http://www.uswaternews.com/archives/arcconserv/5graywate10.html

http://www.uga.edu/coastalnemo/Documents/Literature/SDA_WERF_Graywater_2006.pdf

http://www.uga.edu/coastalnemo/Documents/Literature/SDA_WERF_Graywater_2006.pdf

http://www.mass.gov/dep/water/wastewater/gwstudy.pdf

http://www.water.ca.gov/pubs/conservation/monitoring_graywater_use__three_case_studies_in_california/monitoringgw_use.pdf



http://www.energyrating.gov.au/library/pubs/wa-wateruse.pdf

http://www.circleofblue.org/waternews/2010/world/u-s-urban-residents-cut-water-usage-utilities-are-forced-to-raise-prices/

http://www.circleofblue.org/waternews/2010/world/the-price-of-water-a-comparison-of-water-rates-usage-in-30-u-s-cities/

http://www.tucsonaz.gov/water/usage_comparison.htm


http://www.cimis.water.ca.gov/cimis/infoEtoOverview.jsp

http://www.census.gov/compendia/statab/2010/tables/10s0916.pdf

http://www.eia.doe.gov/emeu/recs/recs2001/enduse2001/enduse2001.html

http://www.robertkourik.com

http://www.tucsonaz.gov/water/docs/isbf-req.pdf

Videos

Document Control

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Graywater irrigation pumping system Connecting IrriGRAY dripperline to poly supply tube using takeoff fittings Rainwater irrigation using IrriGRAY dripperline and gravity Rain barrel pump and hose kit, installation and use Branched drain irrigation system, installation overview (Tucson AZ)

Resources

Date Purpose Of Revision Version

10/25/2010 Minor revisions 1.01

10/12/2010 First Release 1.0

http://www.youtube.com/watch?v=FS1mEXRcrPw



http://www.youtube.com/watch?v=1ITqXa1tihw

http://www.youtube.com/watch?v=0zGkhpA5CX4

Just Water Savers USA Inc. Toll-Free 800.513.6414 Fax: 513.488.1105 WWW www.justwatersaversusa.com www.besthomewatersavers.com www.irrigray.com Administration: Middletown, Ohio Warehouse: Eugene, Oregon

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