CRD Greywater Reuse Study Final Report

Capital Regional District November 1, 2004 Greywater Reuse Study Report File: 1027-42

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EXECUTIVE SUMMARY Governments and regulating bodies worldwide are trying to develop new ways to conserve depleting water resources, and greywater treatment and reuse is one of the key methods being considered. This report has been prepared for the Capital regional District (CRD) to examine greywater reuse. Two types of greywater are examined for reuse: light-greywater (from bathroom sinks, showers, bathtubs and laundry) and dark-greywater (from kitchen sinks, containing organics and oil/grease). Regardless of source, residential greywater contains the same contaminants (but at different concentrations) as blackwater from toilets and urinals (including organics and pathogenic micro-organisms) and must be treated prior to reuse. In British Columbia, wastewater discharged from single family dwellings is regulated under the Health Act - Sewerage System Regulation (SSR), and reclaimed water applications in the province of British Columbia is regulated under the Waste Management Act - Municipal Sewage Regulation (MSR, 1999). The current regulations are barriers to greywater reuse. While clusters of two or more dwellings serviced by a common greywater treatment and reuse system are regulated under the MSR, there is no such provision under the SSR and the reclaimed water requirments under the MSR may be onerous for small private systems. Greywater reuse applications include surface and subsurface irrigation, toilet/urinal flushing, car washing, bathing/showering and landscape impoundments, although the most common applications internationally are subsurface irrigation (depth of at least two feet) and toilet flushing. The type of reuse application dictates the level of treatment required. Greywater reuse systems can be broken down into two basic categories: i) diversion/filtration (with direct application); and ii) biological treatment (with storage). Advanced secondary or tertiary treatment is required if reuse is to include bathing, showering, laundry or storage. Thirteen greywater treatment technologies are examined in this report and twenty-one case studies of greywater reuse are presented. Costs for individual treatment systems vary greatly from $64 for a simple sink diversion system (with no treatment) to $15,000 for a complex treatment system to provide full greywater reuse capabilities, plus the costs of dual plumbing ranging from $10,000 for new construction to as much as $25,000 for retrofit plumbing. In general, cost for greywater treatment technologies will vary according to the complexity of the system, which is usually related to the intended reuse application. Costs for a complete reuse system include the capital and operating/maintenance cost of the treatment system, storage system and the pumping and dual plumbing system to deliver reuse water. More complex treatment systems also have higher maintenance costs and normally require a skilled operator to maintain the system (under an annual contract with the homeowner). The economics of greywater reuse for residential applications are not currently favourable within the CRD due to the availability and relatively low cost of potable water and the high cost of treatment technologies required for unrestricted beneficial reuse applications under the MSR. It is estimated that greywater reuse applications may save in the order of $134 per year in potable


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water charges, but would cost up to $20,000 for new construction systems. Potable water costs may have to increase up to $20 per cubic metre before greywater reuse becomes justifiable from a strictly onsite economic perspective. Offsetting this is the potential capital and operating cost savings that may be realized where centralized wastewater collection and treatment facilities are in place, and/or community water services are present. Reduced wastewater discharges as a result of onsite greywater water reuse applications will reduce both residential wastewater discharges and potable water demands - with potential economic benefits resulting from the ability of the existing infrastructure to serve more connections and delayed capital costs for expansion. Although greywater reuse can provide a number of benefits to the community at large through reduced loading or demandss on existing centralized infrastructure, the serious regulatory barriers and high cost for onsite systems limit the feasibility of widespread greywater reuse systems being used within the Capital Regional District.


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TABLE OF CONTENTS

1 INTRODUCTION......................................................................................................... 1

1.1 OBJECTIVES & PURPOSE OF THIS DOCUMENT .................................................................. 1 1.2 WHAT IS GREYWATER ..................................................................................................... 2 1.3 PROS AND CONS OF GREYWATER USE ............................................................................. 3

2 INTERNATIONAL PERSPECTIVES ....................................................................... 5

2.1 GENERAL ......................................................................................................................... 5 2.2 CANADA AND THE UNITED STATES .................................................................................. 5 2.3 EUROPE............................................................................................................................ 8 2.4 AUSTRALIA ...................................................................................................................... 9 2.5 CHINA ............................................................................................................................ 11

3 GREYWATER TREATMENT TECHNOLOGIES................................................ 12

3.1 APPROACHES TO GREYWATER TREATMENT & REUSE ................................................... 12 3.1.1 Diversion Valves ................................................................................................... 12 3.1.2 Sand Filters ........................................................................................................... 13 3.1.3 Aerobic Biological Treatment Systems ................................................................. 14 3.1.4 Electro-coagulation .............................................................................................. 15 3.1.5 Disinfection........................................................................................................... 16

3.2 DIVERSION TECHNOLOGIES ............................................................................................ 17 3.2.1 Clivus Multrum ..................................................................................................... 17 3.2.2 Envirosink® .......................................................................................................... 18 3.2.3 Greywater Saver ................................................................................................... 19 3.2.4 Aquatron Separator............................................................................................... 20

3.3 FILTRATION ................................................................................................................... 21 3.3.1 Nature Clear “Nature Loo”................................................................................. 21 3.3.2 Biolytix "Grey Water Recycler"............................................................................ 22

3.4 AEROBIC BIOLOGICAL TREATMENT ............................................................................... 23 3.4.1 AquaClarus “Simply Natural”.............................................................................. 23 3.4.2 Equaris Greywater Treatment System.................................................................. 24 3.4.3 Clearwater Treatment System............................................................................... 25 3.4.4 Copa MBR Technology®...................................................................................... 25 3.4.5 Wasser Recycling Solutions .................................................................................. 26

3.5 FLOCCULATION & COAGULATION ................................................................................. 27 3.5.1 Electropure Greywater Treatment System............................................................ 27

3.6 DISINFECTION ................................................................................................................ 27 3.6.1 Chlorination.......................................................................................................... 27

3.6.1.1 Chlorine Dioxide -ERCO™ Chlorine Dioxide Technology............................. 27 3.6.1.2 Blue Crystal Residential Disinfecting Calcium Hypochlorite Tablets ............. 28

3.6.2 Ozonation.............................................................................................................. 28 3.6.3 Ultraviolet Light.................................................................................................... 29

3.7 COSTS ............................................................................................................................ 30

4 CASE STUDIES.......................................................................................................... 31

4.1 NICOSIA, CYPRUS .......................................................................................................... 31


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4.2 MT. HAWTHORN, WESTERN AUSTRALIA ....................................................................... 32 4.3 GRS TANK SYSTEM, WESTERN AUSTRALIA................................................................... 32 4.4 DOUBLE TANK SYSTEM, WESTERN AUSTRALIA ............................................................ 32 4.5 GREYMAX, WESTERN AUSTRALIA ................................................................................. 33 4.6 QUEENSLAND, AUSTRALIA ............................................................................................ 33 4.7 SANTA BARBARA, CALIFORNIA ..................................................................................... 34 4.8 EAST BAY, CALIFORNIA ................................................................................................ 34 4.9 FRANKFURT, GERMANY................................................................................................. 35 4.10 LOUGHBOROUGH UNIVERSITY, UNITED KINGDOM........................................................ 35 4.11 EYNESBURY - VICTORIA, AUSTRALIA ............................................................................ 37 4.12 ROUSE HILL DEVELOPMENT - SYDNEY, AUSTRALIA ..................................................... 37 4.13 CASA DEL AGUA (TUCSON, ARIZONA)........................................................................... 37 4.14 QUAYSIDE VILLAGE, NORTH VANCOUVER, B.C............................................................ 38 4.15 CONSERVATION COOP, OTTAWA, ONTARIO .................................................................. 40 4.16 TORONTO HEALTHY HOUSE, TORONTO, ONTARIO ........................................................ 43 4.17 CHARLES STURT UNIVERSITY THURGOONA CAMPUS .................................................... 46 4.18 INKERMAN OASIS, MELBOURNE, VICTORIA................................................................... 46 4.19 20 RIVER TERRACE - THE SOLAIRE BUILDING, NEW YORK........................................... 47 4.20 GILLETTE STADIUM, FOXBORO, MA ............................................................................. 47 4.21 AUSTRALIAN GREYWATER SYSTEM COST EXPERIENCE................................................. 47

5 BC REGULATIONS AFFECTING GREYWATER REUSE ................................ 50

5.1 HEALTH ACT – SEWERAGE SYSTEM REGULATION......................................................... 50 5.2 BRITISH COLUMBIA BUILDING CODE – NON-POTABLE WATER SYSTEMS ..................... 50 5.3 WASTE MANAGEMENT ACT – MUNICIPAL SEWAGE REGULATION (MSR)..................... 50 5.4 DISCUSSION ................................................................................................................... 51

6 ECONOMICS ............................................................................................................. 53

6.1 COSTS ............................................................................................................................ 53 6.2 ECONOMIC ANALYSIS .................................................................................................... 53

7 SUMMARY ................................................................................................................. 56

7.1 GREYWATER DEFINITION............................................................................................... 56 7.2 CURRENT REGULATORY ENVIRONMENT FOR GREYWATER REUSE IN B.C. .................... 56 7.3 OPTIONS FOR USE OF GREYWATER & LEVEL OF TREATMENT REQUIRED...................... 57 7.4 COMPONENTS OF GREYWATER REUSE SYSTEMS............................................................ 57 7.5 COMPLEXITY OF GREYWATER SYSTEMS. ....................................................................... 58 7.6 TECHNICAL SKILLS NEEDED TO OPERATE GREYWATER SYSTEMS................................. 58 7.7 GREYWATER REUSE SYSTEM CAPITAL & OPERATING COSTS - EXISTING BUILDINGS &

NEW CONSTRUCTION. .................................................................................................... 59 7.8 ECONOMICS OF GREYWATER REUSE .............................................................................. 59


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LIST OF FIGURES Figure 1 Breakdown of household wastewater by source (www.greywater.com) ........................ 3 Figure 2 Clivus Multrum Dosing Basin (from http://www.clivusmultrum.com/greywater.html)18 Figure 3 Aquatron Separator (from http://www.aquatron.se/start.au.html) ................................. 21 Figure 4 Biolytix Filter (from website: http://www.biolytix.com/filtration) .............................. 22 Figure 5 AquaClarus “Simply Natural” System (from website:

http://www.aquaclarus.com/prod_sim_how.htm) .......................................................... 23 Figure 6 Equaris Greywater Treatment System (from:

http://www.alascanofmn.com/default.asp?Page=Wastewater)...................................... 24 Figure 7 Wasser recycling Solution (from http://www.greywater.com/e_s2_konzept.html) ..... 26 Figure 8 Nicosia Household Greywater System (Kambanellas, 2004)........................................ 31 Figure 9 Household greywater treatment system process overview. Gold Coast, Queensland

Australia......................................................................................................................... 34 Figure 10 Amortization of a greywater system in a German hotel (Nolde, 2004).................... 36 Figure 11 Quayside Village Water Reuse Treatment System................................................... 40 Figure 12 Conservation Co-op Greywater Treatment System................................................. 43 Figure 13 Toronto Healthy House Water Reuse Treatment System........................................ 44 Figure 14 Gillette Stadium Water Reuse System Flow Diagram.............................................. 48 Figure 15 Cost of treatment, transport and total cost vs number of connections (Booker, 2000).

................................................................................................................................... 55 LIST OF PHOTOS Photo 1 Envirosink (white funnel in photo) (from http://www.joneakes.com/ca/hs/cgi-

bin/getdetailscahs.cgi?id=1975) .................................................................................... 19 Photo 2 Greywater Saver (from http://www.ecologicalhomes.com.au/econewsFeb04.htm) ..... 20 Photo 3 Kubota Flat Sheet Membranes (from http://www.copa.co.uk/products/mbr/default.asp)

....................................................................................................................................... 25 Photo 4 OzoMax Residential Ozone Generator (from http://www.ozomax.com/ozonator.htm) 28 Photo 5 Casa del Agua demonstration project in Tucson, Arizona (from

http://www.csbe.org/Brittain/brittain_fig1.htm) ............................................................ 38 LIST OF TABLES Table 1 Potable water savings associated with various greywater reuse case studies in Australia

(from Australian Water Association, April 2004) ......................................................... 10 Table 2 Greywater Treatment System Matrix & Costs ......................................................... 30 Table 3 Mt. Hawthorn performance data. ................................................................................... 32 Table 4 GRS tank system performance data. .............................................................................. 32


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Table 5 Double Tank System performance data. ........................................................................ 33 Table 6 Final quality and removal efficiency of primary system (Surendran, 2004). ................ 36 Table 7 Final quality and removal efficiency of secondary system (Surendran, 2004). ............ 36 Table 8 Water quality objectives for Conservation Coop greywater reuse system.................... 41 Table 9 Reuse Water Quality Objectives for Toronto Healthy House ....................................... 45 Table 10 Greywater system materials, costs, energy and maintenance requirements {AUS $}

(from Australian Water Association CSIRO, April 2004) ............................................ 49 Table 11 Greywater system water savings (from Australian Water Association CSIRO, April

2004) .............................................................................................................................. 49 Table 12 BC Waste Management Act – Municipal Sewage Regulation – Reclaimed Water

Criteria ........................................................................................................................... 51 Table 13 Statistical data on water use in the CRD (CRD Website, 2004).................................... 53 Table 14 Estimates of domestic water use for typical Australian households in comparison to the

CRD. .............................................................................................................................. 54 Table 15: Water charges within the CRD (CRD website) ............................................................ 54


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1 INTRODUCTION Due to depleting water resources from high water demand and pollution, governments and regulating bodies worldwide are trying to develop new ways to conserve depleting water resources, and reclaimed water use is one of the key methods being considered. Reclaimed water is wastewater originating from commercial, industrial or residential activities that has been treated or renovated to an acceptable standard for specific uses. This report focuses on the treatment and reuse of residential greywater sources including bathtubs, showers, laundry machines, and sinks within the household. Before being reused, greywater is generally treated, using a variety of treatment technologies of varying sophistication, to a quality where it can be reused for other applications such as sub-surface and landscape irrigation, car washing, street cleaning or toilet flushing. There are a number of available technologies to treat the greywater for specific reuse applications. A discussion of some of these technologies and their various components is presented later in this report. 1.1 Objectives & Purpose of this Document The Capital Regional District (CRD) retained NovaTec Consultants Inc. to prepare and summarize various components of greywater treatment and its application. Components of greywater reuse requested to be covered in the report include: § Greywater definition;

§ Current regulatory environment for greywater reuse in B.C.;

§ Options for use of greywater, and the level of treatment required to meet water quality requirements for each use;

§ Components of greywater reuse systems – collection, treatment, disinfection, storage and recirculation of disposal systems;

§ Complexity of greywater systems;

§ Technical skills needed to operate greywater systems;

§ Cost of greywater reuse systems in existing buildings and new construction – capital and operating costs;

§ Economics of greywater reuse systems based on water rate projection and water savings (simple payback or present value analysis);

§ Case study summaries of existing installations and;

§ Discussions of greywater reuse opportunities for the residential, commercial, institutional and industrial sectors.

This information is intended to assist the CRD in creating future water management strategies for the Region.



1.2 What is Greywater Residential wastewater is a mixture of all water discharges within the household including bathroom sinks, bathtubs, toilets, kitchen sinks, and laundry wash-water sources. This wastewater is characteristically divided into three sub-categories related to the organic "strength" or level of contaminants typically contained in the water: 1) blackwater; 2) dark-greywater, and 3) light-greywater. Blackwater comes from toilets and contains high concentrations of disease causing microorganisms and high levels of organic contaminants. Dark-greywater primarily originates from kitchen sinks, which can also contain disease-causing microorganisms and have high levels of organics contaminants from food waste and grease/oils. Light-greywater typically consists of drainage from bathroom sinks, tubs, showers, and often laundry. It can also contain disease-causing microorganisms but they are usually in much lower numbers than the other two wastewater categories. Although light-grey water is generally also considered to have lower concentrations of organic contaminants than the other two wastewater sub-categories, the level of organic contaminants can be comparable to the other two depending on the circumstances. Ignorance of this fact contributed to the cause of system failure in one of the case studies presented later in this document (see Section 4 - Conservation Coop). Greywater may contain varying levels of disease-causing microorganisms that are washed off during bathing and from clothes during laundering, and may also contain fats, oils, grease, hair, lint, soaps, cleansers, fabric softeners and other chemicals. Soaps and detergents are biodegradable, but they can present problems when greywater is used over an extended period. The main problem with most cleaning agents is that they contain sodium salts which, if present in excessive amounts, can damage the soil structure, can create an alkaline condition. Elevated levels of chlorides, sodium, borax, and sulfates, and high pH (alkaline) characteristics of greywater may be harmful to some plants. Greywater should not be used to irrigate root crops, or edible parts of food crops that touch the soil. In considering the application of greywater reuse it should be kept in mind the kinds of chemicals that may end up being flushed down sinks including: kitchen and household cleaning products, washing detergents, soaps, shampoos and conditioners. These household products can contain a vast array of potentially harmful chemical contaminants that can affect the safety of greywater reuse applications (e.g. petro-chemicals, chlorine, caustics, animal ingredients, sodium lauryl sulfate, etc.). Because all wastewater categories (i.e. black, dark-grey and light-grey water) contain some level of organic contaminants and potential disease causing microorganisms, they should all be given the same consideration with respect to public health risk and safety in considering treatment and reuse applications. Research has shown all greywater carries various levels of bacterial contamination (Ottoson and Stenström, 2002). Even the collection and storage of rainwater for applications within the home require consideration for treatment. Because light-greywater typically has low concentrations of organic and inorganic contaminants, and disease causing microorganisms, it can often be considered for direct reuse (without treatment to reduce the



contaminants) for applications where there is low risk of public contact (e.g. subsurface irrigation, and toilet or urinal flushing), and storage is not required. In contrast both blackwater and dark-greywater both typically require treatment and at least some level of disinfection before they can be stored or safely used for reuse applications. If biological treatment is required because of the need to store reuse-water, because of the level of contaminants present, or because of the desire to apply reuse water for applications in which human contact is likely, the treatment technology required is identical for both blackwater and greywater (i.e. secondary, advanced-secondary, or tertiary treatment with disinfection) and consideration should be given to treating the mixed wastewater stream rather than segregating, treating and reusing only the greywater portion. The biological (secondary) treatment systems described in Section 3.0 intended for use in greywater treatment are identical to the technologies marketed and used for mixed wastewater treatment applications. Figure 1 illustrates a generic approximate proportion of daily wastewater flows generated by a household.

toilet40%

bath30%

misc5%

laundry10%

kitchen15%

Figure 1 Breakdown of household wastewater by source (www.greywater.com)

1.3 Pros and Cons of Greywater Use Pros:

• The obvious key advantage of domestic greywater use is that it replaces or conserves potable water use, and can reduce the cost of potable water supply.

• Appropriately applied, greywater may contain nutrients (e.g. phosphorus and nitrogen from detergents), benefiting plant growth and resulting in more vigorous vegetation.

• Offers potential cost reductions for regional sewage treatment facilities. Removing greywater from residential wastewater drainage to sewer decreases the flow through the sewer and to the treatment plant and enables the existing infrastructure to service more connections. Cost savings could potentially be realized if this delays the need for future capital expenditures to upgrade conveyancing or treatment capacities.



• Offers potential energy savings over centralized sewereage alternatives where onsite greywater reuse applications require limited or no treatment, and where the greywater otherwise would have to be pumped to a centralized treatment plant and treated.

• Greywater could supply most, if not all, of the irrigation needs of a domestic dwelling landscaped with vegetation in a semiarid region.

• In addition to applications for outside irrigation, greywater can also be used for toilet flushing and, if treated to an advanced secondary or tertiary level, can also be used for a wide range of domestic water uses including bathing, showering, and laundry.

Cons:

• Greywater may contain sodium and chloride, or other chemicals that can be harmful to some sensitive plant species. Additionally, greywater is alkaline (high pH) and shouldn’t be used to irrigate acid-loving plants such as rhododendrons or azaleas.

• Resulting diminished sewer flows from domestic greywater could potentially result in insufficient sewer flows in some circumstances to carry waste to the sewer plant (e.g. pipes with low slopes), or may result in a high strength sewage that combined with lower flows may lead to odour and corrosion problems in the centralized sewerage systems.

• Concern regarding the public health implications of greywater reuse, and the need for research to determine the risks of greywater reuse.

• Cost of treatment and diversion/transfer pipe & pumps.



2 INTERNATIONAL PERSPECTIVES 2.1 General Up until recently, greywater reuse applications within the home have not been given a great deal of consideration by regulatory authorities. Greywater treatment and reuse applications have often been carried out on a pilot or demonstration study basis without a regulatory framework, or have been carried out as a retrofit within a building without requiring significant plumbing modifications or related Permits. With the exception of illegal modifications made to plumbing without proper Permits, the prevailing attitude has been ignore greywater reuse applications done within the privacy of the home up to the individual homeowners. As a consequence of the lack of general regulatory interest, homeowners interested in greywater reuse have typically carried out their own research into appropriate reuse applications and alternative commercially available technologies or treatment equipment. The result is often a rather haphazard cobbling together of treatment components with little engineering input to how the components can best be integrated, and a high degree of operations and maintenance required to keep the systems functioning (for example, see Sections 4.14 Quayside Village & 4.16 Toronto Healthy House). While technology verification and certification standards and testing protocols exist for mixed wastewater residential wastewater treatment, none have been developed specifically for greywater treatment. Consequently, there is little information available to assess greywater technology manufacturers' claims, other than anecdotal testimony of other users, or reported in literature case studies. 2.2 Canada and the United States In North America the lack of plumbing codes or other codes of practice have also forced homeowners interested in making modifications to their homes for greywater reuse to make such changes without Permits for household plumbing modifications, posing a potential risk of cross-contamination with potable water lines and connected community water distribution systems. Many greywater reuse applications in North America tend to be one-of demonstration projects involving both passive (plant-based) and mechanical treatment technologies.

• Washwater Garden™’ greywater system installed in Massachusetts, consists of a wetlands planted with bamboo and banana (West, 2003). Filters are added to filter grease from kitchens sinks and lint from the washing machine. Greywater is pumped through a Washwater Garden™ tropical garden with no discharge at the end. They found that some of the leaves on the plants were turning brown, which could indicate low nitrogen. Diverting urine to the system was suggested as a solution to this problem.

• In Arizona “Greywater reuse” refers to the capturing water from lavatory sinks, showers and washing machines for reuse in landscape irrigation and sometimes toilet flushing versus “Wastewater reclamation and reuse”, which refers to treatment of wastewater, typically at a centralized treatment plant, and redistribution to serve needs that can be satisfied by lower quality water, such as landscape irrigation and toilet flushing. The Arizona Department of Environmental Quality (ADEQ) regulates domestic greywater systems and, in some instances, specific counties are involved. Rules permit single and



multi-family residences to use greywater for surface irrigation under certain conditions, including ADEQ approval of the design and construction of the system. The system must include a settling or holding tank to settle out the grit and heavier material from the greywater, and a filtration device is also required. If the greywater is to be applied to the surface, disinfection is also required. Greywater used for surface irrigation must meet allowable water quality and monitoring specifications. Allowable limits are set for fecal coliform and chlorine residuals.

The Doney Park Timberline Fernwood Area Plan is an example of the changes that have occurred since 2002. That plan states, “The reuse of treated wastewater/greywater shall be encouraged wherever possible for both residential and commercial irrigation and for commercial/industrial purposes”. Under the plan, to use greywater for outdoor landscape watering, homeowners obtain a permit from the county Health Department, and in new homes additional piping can be added to use greywater to flush toilets.

About 90 percent of people calling the ADEQ about greywater use are reported to be interested in draining their washing machine directly onto backyard vegetation – which is defined as greywater surface irrigation. The ADEQ rules require the washing machine discharge to first drain into a holding tank and be filtered before it can be discharged through the irrigation system. Daily fecal coliform sampling is required to be done by a state certified laboratory, at a cost of about $100 per sample. This cost is reported to have the effect of deterring people from further considering using washing machine water for irrigation – at least legally. http://ag.arizona.edu/azwater/arroyo/071rain.html

• In New Mexico greywater is defined as "untreated household wastewater that has not come in contact with toilet waste and includes wastewater from bathtubs, showers, washbasins, clothes washing machines and laundry tubs, but does not include wastewater from kitchen sinks or dishwashers or laundry water from the washing of material soiled with human excreta, such as diapers." Regulations passed in 2003 set conditions allowing up to 250 gallons per day of residential greywater to be used for household gardening, composting or landscaping irrigation without a permit if the following conditions are met:

o The gray water distribution system must be constructed so that overflow from the system drains into the sanitary sewer or septic system. In some cases, a liquid waste permit may be necessary if an on site septic system is modified.

o A gray water storage tank must be covered to restrict access and to eliminate habitat for mosquitoes or other vectors. Standing water left in place for more than seven days has the potential to allow mosquitoes to breed and hatch.

o The gray water system must not be located in a floodway.

o Gray water is discharged only in areas where there is vertical separation of at least five feet between the point of discharge and the ground water table to protect ground water resources from possible contamination. Current Liquid Waste Disposal Regulations require that gray water is not applied within 100 feet of a domestic well or within 200 feet of a public water supply.

o Gray water pressure piping is clearly identified as carrying non-potable water.



o Gray water is used on the site where it is generated and may not run off the property.

o Gray water is applied in a manner that minimizes the potential for contact with people or domestic pets. Gray water application methods that reduce contact include drip irrigation, shallow piping systems, or mulch trenches.

o Ponding of gray water is prohibited and application of gray water must be managed to minimize standing water and to prevent saturation of the soil.

o Gray water must not be sprayed. Low-pressure drip irrigation or bubblers located under mulch help to prevent misting and exposure to gray water.

o Gray water must not be discharged to a watercourse. Current Liquid Waste Disposal Regulations require that discharges of gray water be at least 100 feet from streams or lakes or 25 feet (plus the depth of the arroyo) from an arroyo.

o Gray water use shall comply with all applicable municipal or county ordinances and local building codes.

http://www.nmenv.state.nm.us/OOTS/GRAY%20WATER%20IRRIGATION%20GUIDE1.pdf) http://www.legis.state.nm.us/Sessions/03%20Regular/FinalVersions/house/HB0114.htm

• Greywater use was legalized in California in 1992, and the California Department of

Water Resources (CDWR) adopted standards for the installation of greywater systems and greywater reuse applications. CDWR defines greywater as untreated single-family residential wastewater from all sources, excluding toilets, kitchen sinks, and dishwashers, and the application is limited to subsurface drip and mini-leachfield irrigation systems. Unlike Arizona, which defines subsurface irrigation as below two feet, CDWR minimal soil depths for subsurface irrigation ranges from eight (8) inches for sandy soils to twelve (12) inches for clay soils. Irrigation above this soil depth is considered to be a surface application, and stricter rules apply. The CDWR approved subsurface drip irrigation systems must include a surge tank (50 to 100 gallons), and filtration, before the effluent can be pumped through to the drip irrigation system. A surge tank isn’t required for a mini-leachfield irrigation system. California does not require the greywater sampling, monitoring and treatment required by Arizona, and municipalities can adopt the State regulations as a base, or ban greywater applications altogether. http://ag.arizona.edu/AZWATER/arroyo/071rain.html

• A recent study done by the Natural Resources Defense Council (August, 2004) noted the Orange County water recycling system will use only one half the amount of energy required to import the same amount of water from Northern California. Even groundwater pumping in San Diego is more energy intensive than recycling from urban wastewater. A study of 1,200 homes in 14 cities looking at residential water use found that the top four indoor uses were:

o Toilet (26.7 percent);

o Clothes washer (21.7 percent);

o Shower (16.8 percent);

o Faucet (15.7 percent).



Toilets and landscaping account for the two largest residential uses of water. Wastewater recycling in San Diego accounts for about 22 million m3 per year.

• The State of New Jersey Department of Environmental Protection recently promulgated a regulation requiring municipalities filing for a new New Jersey Pollution Discharge Elimination System (NJPDES) or renewing an existing NJPDES Permit to demonstrate that they have investigated the application of reuse of their wastewater. As a consequence, the City of New York Division of Water Supply, Department of Environmental Protection agreed, as part of a rate increase, to offer a discount to any building owner that demonstrates reclamation of their wastewater. This has resulted in a number of large-scale commercial building greywater reuse systems over the past several years (see Case Studies).

• Canada Mortgage and Housing Corporation (CMHC) has carried out most of the research and investigation work leading to greywater and mixed wastewater reuse demonstration projects, examining the potential for water reuse systems to contribute to water conservation planning and design practices associated with water management technology. CMHC has initiated several research and demonstration projects over the past nine years examining mechanical greywater reuse technologies and applications within residential settings. Two greywater reuse initiatives (Sections 4.14Quayside Village, and 4.15 Conservation Coop) and one mixed wastewater1 residential case study (Section 4.16 Toronto Healthy House) are described in the case studies presented later in this report.

2.3 Europe International interest in water conservation measures has resulted in a recent interest in implementing greywater reuse strategies within the home and the development of standards and regulatory codes of practice. Many communities in Europe are using natural systems treat their greywater (West, 2003). The following are examples of some of these initiatives: § In Norway a constructed wetland system has been designed to treat greywater on-site,

from a student dormitory. The system uses only 2m2/person to treat greywater and toilet wastewater.

§ In Oslo, Norway a landscaped, compact natural system is being used to treat 33

apartment homes. The system uses only 1m²/person. Additional aeration occurs over the summer months and greywater is treated to a swimming water quality.

§ In Sweden urine is separated from feces and toilet paper. The feces and toilet paper are

treated by an Aquatron system. Greywater is treated by a Bioclere trickling filter, and then is further polished by a constructed pond, a constructed stream and a natural

1 Mixed wastewater consists of blackwater (toilets & urinals) combined with greywater (bath tubs, showers, sinks, and laundry) as described in Section 1.0



wetland. The separated urine from all of the homes is piped and stored, where local farmers use it as a fertilizer in spring and autumn.

§ In Denmark greywater is treated by a willow evopo-transpiration bed. The system has no

discharge. Effluent is reduced through evaporation and transpiration. § In Scandinavia they use Aquatron’s fecal and urine separating toilets. Urine is separated

and stored. After six months of storage the urine is sprayed on or injected into agricultural land.

2.4 Australia Australia appears to be at the forefront of the move to implement greywater reuse as one of the key methods of residential water conservation. In June 2004, Queensland State Cabinet endorsed the use of recycled water from showers and washing machines for use in garden irrigation following “extensive tests to ensure the untreated greywater will not pose a health hazard” (ABC News Online: Friday, June 4, 2004. 7:35pm (AEST)). Queensland also commissioned a study to determine if existing funding arrangements in use in Queensland are hindering the advancement of water recycling (PriceWaterhouseCoopers, 2000). The study notes that local governments implement a large portion of the water recycling schemes, many of which are funded up to 50% by the State government, and recommends effluent charges at the discharge end of the water cycle as means of encouraging water recycling. New South Wales (NSW) in Australia has initiated an ambitious Building Sustainability Index project called “BASIX”, which is a web-based planning tool that assesses residential development proposals for a range of sustainability indices including landscape, stormwater, water, thermal comfort and energy (http://203.110.153.11/information/about.jsp ). Building applicants are responsible for completing a BASIX assessment for each residential development proposal as part of the development approval process. The applicant enters information about a proposed development, such as site location, dwelling size, floor area, landscaped area and services, and the development is scored according to its potential to consume less water or energy than average existing dwellings. The first stage of BASIX compares the proposed residential developent with average existing homes with respect to reducing water and energy consumption. Effective July 1, 2004, all new single and dual occupancy dwellings are required to complete a BASIX assessment as part of the building application process. Residential development must be designed and built to use 40% less drinking-quality water and produce 25% less greenhouse gas emissions than average NSW homes of the same type. This is accomplished by electing to implement various water conservation measures including the use of greywater reuse technologies. With respect to water conservation, a typical development is expected to meet the target for water conservation if it includes the following elements: (http://203.110.153.11/information/about.jsp)



• showerheads and tap fittings with at least a "3A" 2 rating;

• dual flush toilets; and

• a rainwater tank or equivalent communal system of a minimum specified volume, or a connection to an appropriate recycled water supply for outdoor garden water use and toilet flushing and/or laundry.

This includes treated and diverted greywater use with optional applications for toilet flushing, laundry, and garden irrigation. It is estimated that greywater (bathroom tub/sink shower, and laundry sources) accounts for 40% of all water used by domestic dwellings and about 70% of all of the wastewater created in Australia (See estimated water savings due to greywater reuse in Table 1). (ref. http://www.ecologicalhomes.com.au/econewsFeb04.htm#Story#1) The applicant for a development completes an online web-based BASIX assessment of the project and obtains a BASIX Certificate, which is then submitted with the development application. The development certificate issued by the authority includes a prescribed condition imposing the commitments listed in the BASIX Certificate, and these commitments must also be included in all construction certificate plans and specifications, and the development must be carried out in accordance with the commitments. (http://www.iplan.nsw.gov.au/basix/pdf/basixdatainputchecklist.pdf ) (http://www.iplan.nsw.gov.au/basix/pdf/designguidelines/w01_what_water_source.pdf ) As of February 1, 2005, the program will include proposed multi-unit residential developments, with state-wide application for all development proposals by July 1, 2005, and all renovations by October 1, 2005 (http://203.110.153.11/information/exhibition.jsp ).

Table 1 Potable water savings associated with various greywater reuse case studies in Australia (from Australian Water Association, April 2004)

2 The designation ‘3A’ refers to a water consumption efficiency rating for a specific fixture as defined in the BASIX Calculation Manual (http://www.basix.nsw.gov.au/information/common/pdf/method_full.pdf) with the higher index number (i.e. 1A, 2A or 3A) indicating a greater water conservation efficiency. For example, a toilet with a water consumption of 4 Litres per flush has a 3A rating, whereas one using 5.5 L/flush has a 2A rating, and one using 6.5 L/flush has a 1A rating.



2.5 China Beijing and Tianjin3 have advanced municipal regulations for water reuse targeted at larger buildings (up to 30,000m2)4 that requires on-site greywater treatment and reuse systems. China’s rapid economic growth (8 to 10%) has created a water crisis that the government is addressing through a number of policies, including regulations requiring greywater treatment and water reuse for larger scale institutional buildings and residential developments.5 Policies advancing water reuse technology applications have been progressively evolving since the Water Law of the People's Republic of China was adopted at the Twenty Fourth Meeting of the Standing Committee of the Sixth National People's Congress on January 21, l988 (revised 1998).6 Water reuse is being addressed at multiple market levels, industrial, municipal (large scale systems) and at the smaller scale of commercial, institutional and residential on-site greywater reuse. Early research on reuse applications dates back to Luo’s 1994 paper: Prospects for Wastewater Treatment and Reuse in Beijing Municipality.7 These studies indicate that wastewater reuse has improved significantly over the past two decades rising from 45.3 % in the early 1980s to 91.4% in 1996. Beijing factories have either met the standard for water reuse or they have closed or been relocated. Beijing water utility planners note that:

With rapid social and economic development, Beijing is facing water shortages. In the past ten years, the average water consumption in Beijing urban area was increasing steeply with total water consumption rising to 1.007 billion m3. In the Capital’s 21st Century Water Resources Plan, it is predicted that the gap between water requirement and natural water supply will be 1.2 to 3.0 billion m3 in 2010. …With advanced wastewater treatment technologies the reuse of sewage is now not only possible but has also been widely proved to be safe and reliable.8

The greywater treatment systems in use in China typically incorporate either activated sludge or fixed film (e.g. rotating biological contactor) biological treatment technologies, with limited operational success. While the laws require the provision of greywater reuse technologies, there has been no enforcement to verify their performance. The overall pragmatic objective is to conform to the laws and provide equipment at the lowest possible cost. The technologies often do not work. This is changing with as the regulatory authority’s capacity to monitor performance increases. 3 Tianjin already has a number of demonstration projects for commercial and industrial water reuse in place including a 12,000m3/day Meijiang residential district for toilet flushing and garden watering, other projects include nursery irrigation, car washing and power plant cooling; as reported in: Xingcan Zheng Research and Pilot Projects on Municipal Water and Wastewater Reclamation and Reuse in China, National Engineering Research Centre, for Urban Water and Wastewater, Tianjin, China. http://lnweb18.worldbank.org/ESSD/essdext.nsf/18ByDocName/ResearchandPilotProgramonMunicipalWastewaterReclamationandReuseinChina--PowerpointPresentation/$FILE/ZhengXingcanpresentationoutline.pdf 4 Haifeng, J. et al, (2004) Research on Wastewater Reuse Planning in Beijing Central Region, Proceedings of the 1st International Conference on Onsite Wastewater Treatment and Recycling. Perth, Australia. 5 The Chinese Ministry of Water Resources estimates that 400 of 658 cities are suffering from water shortages. 6 Asian International Rivers Centre (AIRC), Yunnan University, Nov. 27, 2003, Kunming, Yunnan, China. 7 Luo, T. (1994) "Prospects for Wastewater treatment and Reuse in Beijing municipality," in Water and wastewater treatment. Ed. International Conference and Exhibition on Water and Wastewater. International Academy Publishers. Beijing, PRC. 8 Haifeng, J. et al, (2004) ibid,



3 GREYWATER TREATMENT TECHNOLOGIES 3.1 Approaches to Greywater Treatment & Reuse Greywater treatment approaches range from simple low-cost devices that route greywater directly to applications such as toilets and garden irrigation, to highly complex and costly advanced biological treatment processes incorporating sedimentation tanks, bioreactors, filters, pumps and disinfection systems. There are a number of greywater systems commercially available, and may include one or more components including: primary solids separation, oil and grease removal, filtration, aerobic biological treatment, coagulation and flocculation, and disinfection. Some of these systems are able to remove pollutants and bacteria from greywater and the better systems include settling tanks, biological reactors and sand filters, enabling the treated greywater to be stored until needed without adverse conditions occurring (e.g., foul odours, corrosion, etc.) 3.1.1 Diversion Valves A wide range of greywater treatment technologies exist of varying designs according to the level of treatment required and the intended reuse (water quality) application. A diversion device is probably the simplest and most common method of greywater reuse. Diversion devices direct untreated greywater typically from laundry or bathroom sinks to a sub-surface garden irrigation system. Sub-surface drip irrigation systems minimize human contact with the greywater and, therefore, are one of the more common irrigation distribution methods for greywater. Rather than relying on gravity feed systems, some greywater diversion schemes drain greywater to a tank fitted with an effluent pump, which pumps the greywater to a sub-surface irrigation field. Where kitchen sinks are included in a diversion greywater system, a grease trap, screen and/or settling tank is used to separate out grease and large solids that would otherwise clog piping. Pros:

• Simple manual (hand adjust or preset) operation • Very low maintenance requirements (period manual screen cleaning). • Ability to divert greywater for immediate reuse as required or desired. • Very low capital and operating cost

Cons:

• No or limited (screening) treatment provided. • Cannot store without risk of odour and other problems. • Does not kill or reduce the number of disease-causing microorganisms (pathogens) that

may be present. • Reuse application typically limited to immediate sub-surface irrigation only.



3.1.2 Sand Filters Sand filters usually consist of beds of sand or in some cases coarse bark or mulch, which trap and adsorb contaminants as the wastewater flows through it. "Sand filters', depending on the design, can have two treatment functions which are not necessarily inclusive: 1) physical filtration (separation) of particulate matter; and 2) biofiltration (i.e. intermittent or recirculating sand filters) which involves phsycial particlate separation, and the adsorption and biodegredation of soluble and particulate organic contaminants from the greywater. If the sand filter is open at the surface and the flow rate is intermittent and/or low enough to maintain aerobic conditions (i.e. the supply of oxygen) for fixed-film bacteria to treat the greywater (i.e. intermittent or recirculating sand filter) the filter can provide biological treatment of the trapped organic material. Biological treatment in sand filters involves the breakdown of organics by bacteria and other microorganisms as well as snails, worms and insects. If the sand filter is flooded but open at the surface (i.e. slow sand filter) less oxygen is provided to attached-growth bacteria and a lower level of biological treatment is expected. If the sand filter is pressurized within a container, or subject to high flows (i.e. a sand filter typically designed for physically removing sediment and particulates for potable water treatment), and no oxygen source is provided, then no biological treatment is expected. Effluent from such greywater sand filter systems may be collected and redirected directly to either subsurface irrigation or toilet flushing, but should not be stored without first being biologically treated to remove soluble and particulate organic material. Storing greywater without first having been biologically treated can result in anaerobic (septic) conditions, and odours (e.g. see Section 4.15 Conservation Coop case study). The land area required for sand filtration depends on the degree of biological treatment required or expected. For example, internmittent sand filters or recirculating sand filters will require significantly more land area than a pressure-vessel style sand filter only providing phsyical filtration of particulates. Intermittent sand filters may require up to 400 square feet per household, whereas recirculating biofilters may require as little ast 20 square feet. Greywater should pass through a settling tank and possibly a grease trap or screen prior to treatment through a sand filter to reduce loading to the filter and avoid clogging. Properly designed, sand filtration systems have the ability to treat greywater to a high standard, with low maintenance and cost. Pros:

• Simple operation. • Low maintenance. • Some biological treatment provided facilitating limited duration storage and increased

application options than valve diversion alone. • Low operating cost



Cons: • Potentially incomplete biological treatment with no ability to adapt to varying greywater

characteristics if not properly designed and sized. • High capital cost. • Reduces the number of disease-causing microorganisms (pathogens) that may be present,

but does not eliminate them (i.e. does not disinfect). • High land area requirements for biological treatment in comparison to alternative

mechanical-based biological treatment systems. • Subject to clogging and flooding if overloaded.

3.1.3 Aerobic Biological Treatment Systems Aeration of greywater facilitates aerobic biological treatment that characteristically results in a typically higher effluent quality than achievable with single-pass or slow sand filtration. The greywater may be discharged into a tank in which air is bubbled to transfer oxygen from the air into the liquid. Bacteria present in the greywater consume the dissolved oxygen and digest the organic contaminants, reducing the concentration of these contaminants and, in turn, also producing more bacteria. The air bubbled into the tank also provides mixing energy to keep the bacteria from settling. Some aerobic treatment systems include support media (usually corrugated plastic sheets or suspended extruded plastic segments) for bacteria to attach to and grow on. The support media may be completely immersed in an aerated greywater, sprayed with greywater (oxygen is passively dissolved into the liquid as it trickles over the media), or the media may be cyclically suspended in the air (to supply oxygen) and then immersed in liquid (to supply food). One common method of cycling media through air and liquid is a rotating biological contactor (RBC), which consists of a series of large parallel discs that are rotated on a common shaft such that half the disk is immersed in liquid (food) while the other half is exposed to the air (oxygen). The discs are slowly rotated through the greywater. Aerobic treatment systems typically are followed by a clarification stage to remove the suspended bacteria, and may be preceded by a septic tank to settle solids and remove oils & grease. Depending on the reuse application, the treated effluent may also be disinfected prior to use or storage to kill bacteria, viruses and other disease causing microorganisms. Common disinfection methods include chlorine, ultraviolet light, and ozone. Pros:

• Potential for high degree of biological treatment. • Less land area required for treatment than biological sand filter systems. • High degree of operations flexibility to accommodate varying greywater strengths and

flows. • Suitable for treating mixed wastewater for reuse applications if effluent is filtered and

disinfected - which also allows the reuse water to be stored.



Cons:

• Complex operational requirements. • High operating cost. • High capital cost. • Can be subject to process upsets due to high greywater flows or chemicals present,

resulting in poor effluent quality or discharge of large quanities of solids (sludge) that may block downstream irrigation pipe or create problems for reuse applications (e.g. sludge or sediment buildup in toilet tanks, reduced disnifection effectiveness etc.)

• Greater amount of operation and maintenance required than for other equivalent treatment systems.

3.1.4 Electro-coagulation Electro-coagulation involves adding coagulating metal ions to the greywater using electrodes. These ions coagulate the contaminants in the water, similar to coagulating chemicals such as alum and ferric chloride, enabling them to be more easily removed by settling or floating (fine bubbles – dissolved air flotation {DAF}). Pros:

• Non-biological treatment therefore is not necessarily adversely affected by chemicals that would otherwise upset a biological process.

• Typically less land area required in comparison to biological treatment. • Does not rely on gravity settling (clarifier) to remove particulates. • Suitable for treating mixed wastewater for reuse applications if effluent is filtered and

disinfected - which also allows the reuse water to be stored. Cons:

• Complex operational requirements. • High operating cost for power and replacement of electrodes. • High capital cost. • DAF may not operate efficiently. • Chemicals often required, resulting in high operations and maintenance requirements. • Typically, greater amount of operation and maintenance required than for other

equivalent biological treatment systems. • May not remove organic contaminants adequately to permit significant storage, which in

turn would restrict reuse applications. • Not commonly used to treat municipal wastewater, and there is limited operating

experience available.



3.1.5 Disinfection Disinfection may be achieved using chlorine, ozone, or ultraviolet light. The most common and simplest method of disinfection is chlorination, usually achieved in greywater systems using sodium hypochlorite “pucks” similar to that used in disinfecting swimming pool water. Ozone is another means of chemical disinfection, typically generated onsite using a device that applies a high voltage-potential to air, and bubbling the ozonated air through the treated greywater. Finally, disinfection using ultraviolet light is becoming increasingly popular, as no chemicals are required. Chlorine Pros:

• Low operator skill requirement. • Highly effective if properly designed and operated. • Low capital cost. • Typically lower operating cost for chemicals and operator O&M than ozone or U.V.

technologies. • Provides a residual disinfectant to ensure reuse water remains disinfected during

prolonged storage. Chlorine Cons:

• Chlorine reacts with residual organic contaminants to form potential carcinogens. • Chemical handling requirements.

Ozone Pros:

• Limited operator skill level required. • No chemical storage or handling requirements (ozone generated onsite). • Eliminates colour and precipitates residual contaminants. • Typically less maintenance than U.V. systems.

Ozone Cons:

• Disinfection efficiency adversely affected by variations in organic content of greywater and flows.

• Ozone is toxic and off-gas must be destroyed. • Results in a precipitate that must be subsequently removed. • Higher operating cost than chlorination systems for operator attention and electricity. • Higher capital cost in comparison with chlorination or U.V. systems. • No disinfection residual.



Ultraviolet (UV) Pros:

• Low operator skill level required. • No chemical storage or handling requirements (ozone generated onsite). • No off-gas or chemicals to handle.

Ultraviolet (UV) Cons:

• Disinfection efficiency adversely affected by variations in organic content of greywater, flow and colour (UV absorbance).

• Adversely affected by particulates present in the treated water. • Higher operating cost than chlorination systems (electricity & cleaning maintenance). • Higher capital cost in comparison with chlorination systems. • No disinfection residual. • U.V. lamp tubes are subject to biological growth and chemical coating phenomena that

interfere with U.V. transmission and disinfection, requiring the lamp tubes to be regularly cleaned to ensure effective performance.

3.2 Diversion Technologies 3.2.1 Clivus Multrum Description: The Clivus Multrum greywater irrigation system consists of a dosing basin, effluent pump, water level controls, and covered irrigation troughs. Greywater flows into the dosing basin. Once the liquid level is high enough level controls in the dosing basin engage the effluent pump, which pumps greywater to irrigation troughs and distributing the greywater evenly to the surrounding vegetation. Water, soap residue, and the small organic particles carried in greywater are discharged directly to plant roots and soil organisms, which consume the organic biodegradable contaminants and adsorb other inorganic and non-biodegradable components of the greywater. Contact information: Clivus Multrum, Inc. 15 Union Street Lawrence, MA 01840 toll free: 800-425-4887 phone: 978-725-5591 fax: 978-557-9658 http://www.clivusmultrum.com/greywater.html



Figure 2 Clivus Multrum Dosing Basin (from http://www.clivusmultrum.com/greywater.html)

3.2.2 Envirosink® Description: Envirosink consists of a white plastic funnel that drains any discharge into it directly to a greywater system (treatment or direct use). The funnel is typically installed over one of the sink holes. The user determines what liquid is suitable for greywater reuse and what needs to be discharged to sewer. The greywater capture is achieved by swinging the tap over the Envirosink funnel, or by using a bowl to capture the greywater and then pouring it into the Envirosink. The Envirosink retails for approximately $75. Contact information: Envirosink Canada 8584 - 145A Street Surrey, B.C. V3S 2Z2 Canada Tel: 888-663-4950 FAX: 604-591-8510 E-Mail: [email protected] http://www.envirosink.com/about.html



Photo 1 Envirosink (white funnel in photo) (from http://www.joneakes.com/ca/hs/cgi-

bin/getdetailscahs.cgi?id=1975)

3.2.3 Greywater Saver Description: Similar in concept to the Envirosink, the Greywater Saver consist of a manually operated gate valve, which users can open or close to select whether their greywater is diverted for garden irrigation or disposed to the sewer or onsite wastewater system. The Greywater Saver has a removable stainless steel mesh filter basket that is used to filter out larger particles from the greywater such as lint and hair. The stainless steel mesh filter can be removed for regular cleaning through the unit’s removable gas-tight screw cap access cover. Filtered greywater flows by gravity from the device through 50mm diameter pipes to irrigation trenches (90mm diameter pipe with 20mm holes, surrounded by rock aggregate), which are located just beneath the surface of garden beds. Even distribution of filtered greywater to each of the piped irrigation trenches is achieved using Greywater Saver Flow Splitter 50mm diameter Y-junction fittings. These fittings are specially designed to split a single stream of filtered greywater under gravity into two equal volume streams. The device costs about $500, plus the costs of installation ($300) and ground dispersal system (an additional $700).



Photo 2 Greywater Saver (from http://www.ecologicalhomes.com.au/econewsFeb04.htm)

Contact information: Postal Address: Post Office Box 7082, Spearwood. W.A. 6163 phone mobile: 040 331 9410 Fax: 08 9467 6154 http://www.greywatersaver.com/contact.htm e.mail: [email protected] 3.2.4 Aquatron Separator Description: The Aquatron Separator system can be used with standard toilets (flushing volume 3-6 litres) or special toilet models where the urine is mechanically diverted from the flushing water and the solid waste in the bowl itself. When the toilet is flushed, the contents of the bowl are transported to the Aquatron Separator where the solids are separated from the liquid using the momentum of the flushing water, centrifugal force and gravity. Solid waste (paper and faeces) falls down into a Bio-Chamber where the solids are digested (composted) by bacteria and (optionally) worms. Approximately 300 worms may be placed into the Bio-Chamber to start the process. Freezing will kill the worms, and the optimal temperature for composting is 12-25 degrees Celsius. The Bio-Chamber is ventilated and the digested solids may be added to garden compost or directly to soil in the garden depending on the degree of decomposition. The liquid is treated by ultra violet light to kill bacteria and viruses, before being reused.



Figure 3 Aquatron Separator (from http://www.aquatron.se/start.au.html)

Contact Information: Mail: Box 2086 SE-194 02 Upplands Väsby, Sweden Phone: +468 590 304 50 Fax: +468 590 304 94 3.3 Filtration 3.3.1 Nature Clear “Nature Loo” Description: Nature Clear “Nature Loo” greywater treatment system consists of a filtration tank, just under 1 cubic metre in volume, which is filled with pine bark lying on top of a fine sand filter. The pine bark provides coarse filtration of large particles such as grease particles or lint from laundry. The sand filter traps finer particles and polishes the water by reducing the organic content of the water. The pine bark is separated from the sand by filter cloth. The filtered material and bark will compost over time and should needs to be removed every six months and replaced with fresh bark. Filtered greywater is then discharged directly to an irrigation trench or other greywater application. In order for the filtration tank to work effectively, it is best to remove food scraps and grease from the kitchen greywater, and a grease trap is required to ensure the filter does not become clogged with grease.



The Nature Clear Filtration Tank costs about $750 excluding sand and pine bark. Contact Information PO Box 2157 Toowong (Brisbane) QLD 4066 Australia Phone: +61 (07) 3870 5037 Fax: +61 (07) 3870 5088 Email: [email protected] http://www.nature-loo.com.au/greywater/natureclear/natureclear.html 3.3.2 Biolytix "Grey Water Recycler" Description: The Biolytix Filter separates the organic matter from the greywater and enables microorganisms to aerobically digest the organic material trapped by the filter. The layered filter collects the organic material at the top surface, allowing the water to filter down through the filter and be pumped from the bottom. Filtered greywater is then pumped directly to a reuse application.

Figure 4 Biolytix Filter (from website: http://www.biolytix.com/filtration)

Contact Information: Biolytix Technologies Pty Ltd - Sales & Product Information: 1300 881 472 Phone: 07 54352700 - Fax: 07 54352701 PO Box 591, Maleny, QLD, 4552 ABN: 11 097 798 966 http://www.biolytix.com/filtration Email: [email protected]



3.4 Aerobic Biological Treatment 3.4.1 AquaClarus “Simply Natural” Description: The AquaClarus “Simply Natural” treatment system consists of a 3 m3 tank that is connected to a vegetation cell and subsurface effluent dispersal trenches. The treatment tank is filled with alternate layers of coarse and fine media, and bacteria that become attached to the media are provided oxygen through passive ventilation. The liquid passing through the treatment tank is collected in chamber, and is periodically recirculated back onto the media. When the liquid level in the chamber reaches a specific level, a pump is activated that transfers the treated effluent to the soil dispersal trenches. The manufacturer refers to the media filled treatment tank as a “vertical wet composting / decomposition chamber. Solids accumulating in the treatment tank are broken down by bacteria and digested by worms and other invertebrates. The resulting worm manure (vermicast) is periodically pumped with a small amount of liquid to the vegetation cell, where it provides nutrients for the plants. The manufacturer plans to release an upgrade product in 2004 called the “Super Natural” which will allow the treated water to be reused for irrigation and other domestic reuse applications.

Figure 5 AquaClarus “Simply Natural” System (from website:

http://www.aquaclarus.com/prod_sim_how.htm)

Contact Information: Phone: Sydney Office: 1300 368 158 Brisbane Office: (07) 3804 1522 fax.: Sydney Office: 1300 368 058 Brisbane Office: (07) 3804 1533 http://www.aquaclarus.com/prod_sim_how.htm by e-mail... [email protected]



3.4.2 Equaris Greywater Treatment System Description: The Equaris greywater treatment system is an activated sludge process in which greywater is drained to a series of tanks including: a surge tank for flow control, 2) an aeration tank to biologically digest organic material under aerobic conditions; and 3) a clarification tank to settle bacteria generated in the aeration tank and transfer the settled biosolids back to the surge tank. An air compressor provides oxygen and mixing energy to the aeration tank by bubbling air through liquid in the tank. The estimated treatment capacity of the Equaris greywater treatment system is 250 gallons per day.

Figure 6 Equaris Greywater Treatment System (from:

http://www.alascanofmn.com/default.asp?Page=Wastewater)

Contact Information: Equaris Corporation 15711 Upper 34th Street South P.O. Box 6 Afton, MN 55001-0006 Phone: 651-337-0261 Fax: 651-337-0265 [email protected] http://www.alascanofmn.com/default.asp?Page=Wastewater



3.4.3 Clearwater Treatment System Description: The ClearWater greywater treatment system is similar in concept to the Aquaris system and consists of three chambers or tanks in series. The system is an aerated activated sludge process that includes a primary solids separation tank, an aerated biological treatment tank to digest organic contaminants, and a final clarification tank to settle generated bacteria and transfer the biosolids to the primary solids separation tank. The process has a nominal treatment capacity of 250 gallons per day, and has a minimum hydraulic retention time of 18 hours. Contact information: AlasCan of Minnesota, Inc 8271 90th Lane, PO Box 88 Clear Lake, MN 55319 (320) 743-2909 (320) 743-3509 http://www.epa.gov/region1/assistance/ceitts/wastewater/techs/clearwater.html 3.4.4 Copa MBR Technology® Description: The Copa MBR Technology® is an aerobic biological treatment process that incorporates Kubota flat sheet membranes within a stainless steel tank which is subjected to coarse bubble aeration. The membrane panels have a nominal pore size of 0.1 to 0.4 microns that in operation become covered by a layer of cellular material that further enhances the filtration. The treatment process produces a high quality biologically treated effluent that is well suited for effective disinfection with ultraviolet radiation.

Photo 3 Kubota Flat Sheet Membranes (from http://www.copa.co.uk/products/mbr/default.asp)



Contact information: Head Office: Copa Ltd. Crest Industrial Estate Pattenden Lane Marden Tonbridge Kent TN12 9QJ Tel: +44 1622 833900 Fax: +44 1622 831466 http://www.copa.co.uk/products/mbr/default.asp 3.4.5 Wasser Recycling Solutions Description: Greywater is collected separately from blackwater and then treated by a rotating biological contactor (RBC) biological treatment system. The RBC consists of polyethylene sheets that are rotated into the liquid. Attached growth bacteria are cyclically immersed in the greywater (providing food) and then exposed to air (oxygen). The attached bacteria eventually fall off of the polyethylene sheets and are removed in a secondary settling tank. The biologically treated greywater is then disinfected using UV-radiation and stored in a service water tank. The storage tank is automatically replenished with drinking water when the service water is in short supply.

Figure 7 Wasser recycling Solution (from http://www.greywater.com/e_s2_konzept.html)

Contact Information: http://www.greywater.com/e_s2_konzept.html



3.5 Flocculation & Coagulation 3.5.1 Electropure Greywater Treatment System Description: In the Electropure system, electrodes are used to pass an electric current through the greywater inside a reactor releasing metal ions and gas bubbles. The metal ions precipitate contaminants in the greywater, and the gas bubbles float the precipitates to the surface of the tank where they are skimmed off and removed. Contact information: Electropure International Pty Ltd 242 Canterbury road Canterbury NSW 2193 Australia Phone: +61 2 9787 6333 Fax:: + 61 2 9718 8222 E-mail: [email protected] http://www.electropure.com.au/techinfo/index.html 3.6 Disinfection 3.6.1 Chlorination

3.6.1.1 Chlorine Dioxide -ERCO™ Chlorine Dioxide Technology Description: The ERCO™ system uses chlorine dioxide to disinfect effluents. Chorine dioxide is a yellowish-green gas that is typically generated onsite. Although chlorine dioxide is unstable as a gas (decomposing into chlorine gas, oxygen gas, and heat) it is soluble in water and is stable as an aqueous solution. Contact Information: Information Request Coordinator: Sherrie Tack ERCO Worldwide 302 The East Mall, Suite 200 Toronto, Ontario, Canada M9B 6C7



Telephone: 416-239-7111 Fax: 416-239-8091 http://www.clo2.com/index.html 3.6.1.2 Blue Crystal Residential Disinfecting Calcium Hypochlorite Tablets Description: Blue Crystal disinfecting tablets are composed of calcium hypochlorite. The tablets provide a simple means of disinfecting treated effluents over the wide range of flow rates that are common to residential systems. The tablets are conveniently dispensed using a tablet feeder, or stacking tube. As the calcium hypochlorite tablet at the bottom of the tablet feeder is dissolved into solution, it is replaced by the tablet stacked above it. Contact Information: Norwalk Wastewater Equipment Company, Inc. 220 Republic Street Norwalk, Ohio U.S.A. 44857-1196 Phone: (419) 668-4471 Fax: (419) 663-5440 3.6.2 Ozonation Description: Ozone is generated by passing air across a high voltage source. Ozone is very reactive form of oxygen that can oxidize a wide variety of contaminants and microorganisms. Unlike chlorine, ozone does not produce any toxic by-products. Ozone has high oxidizing power and is an effective disinfectant that is generated onsite.

Photo 4 OzoMax Residential Ozone Generator (from http://www.ozomax.com/ozonator.htm)



Contact Information OZOMAX LTD 600 Robitaille Granby, Quebec Canada J2G 9J6 Phone: (450) 378-6825 Fax: (450) 777-0264 E-mail: Ozomax Ltd WEDECO Ozone Technologies North America 14125 South Bridge Circle Charlotte, NC 28273, USA Tel. 704-716-7600 Fax 704-716-7610 3.6.3 Ultraviolet Light Description: Ultraviolet (UV) disinfection technology is a proven solution for contamination from harmful microorganisms including bacteria, viruses, spores, and cysts. UV systems transfers electromagnetic energy from a mercury arc lamp to an organism's genetic material (DNA and RNA). When UV radiation penetrates the cell wall of an organism, it destroys the cell's ability to reproduce. UV disinfection is a physical process rather than a chemical one, and there is no residual effect that can be harmful to humans or aquatic life. UV technologies are relatively easy for homeowners to use as there is no need to generate, handle, transport, or store toxic/hazardous or corrosive chemicals. However, they are also adversely affected by turbidity and total suspended solids (TSS) in the wastewater that can be the result of poor operator attention or servicing. Contact Information: Trojan Technologies Inc. Head Office (Canada) 3020 Gore Rd, London, Ontario, Canada, N5V 4T7 Tel: (519) 457-3400, Fax: (519) 457-3030 Email: [email protected] WEDECO UV Technologies North America 14125 South Bridge Circle Charlotte, NC 28273, USA



Tel. 704-716-7600 Fax 704-716-7610 http://usa.wedeco.de/Consumer___Residenti.278.0.html 3.7 Costs Table 2 provides a summary of the foregoing range of greywater treatment technologies and their components. Costs shown for individual treatment systems vary greatly ranging from $64 for a simple Envirosink system to $15,000 for the more complex Equaris system. In general, cost for greywater treatment technologies will vary according to the complexity of the system, which is usually related to the intended reuse application.

Table 2 Greywater Treatment System Matrix & Costs

* Note costs are presented only for those technologies which either publishes such information or where the cost information was presented in the literature.



4 CASE STUDIES 4.1 Nicosia, Cyprus In 1997 the region of Nicosia in Cyprus began an experimental greywater reuse program. It involved a hotel, a stadium and five houses (Kambanellas, 2004). Cyprus has a population of around 700,000 people but is visited by over 2.5 million tourists a year. The water resources in the area are almost fully developed and the greywater scheme was started as part of an initiative to conserve water at the household level. Studies determined that only 50% of the water supply needed to be of drinking water quality, and a plan was developed to use “processed water” to reduce drinking water demand. The first systems were installed in 1997, and seven units were installed by the end of 1998. Greywater is collected from laundry, baths, showers, hand washing basins, and laundry, which amounted to 36 litres a day of the total daily consumption of 122 litres (or 33% of total daily consumption). This greywater was treated, and then used to irrigate gardens or stored for use in flushing toilets. The small amount of settled material accumulated was discharged to the septic system. In the stadium the showers used by soccer players was used to water the field. In the hotel the water from the showers for the pool was reused to water the gardens. After this two year experiment the Cyprus government decided to begin subsidization of installation of treatment plants. The cost of a household plant with a capacity to treat 1 cubic metre per day cost approximately $2000 CDN, and the government now pays over half.

Figure 8 Nicosia Household Greywater System (Kambanellas, 2004).



4.2 Mt. Hawthorn, Western Australia The Mt. Hawthorn greywater system in Western Australia is very new, and its characteristics are not yet well understood. The greywater from the laundry is filtered and used directly in the gardens. The system employs a basic filter-bag and an overflow pipe. The bag reduces suspended solids by 50%, and the data indicates there may be some nutrient reduction; however, as the system is very new, more testing is required. The expected daily flow for this device is 157 L a day.

Table 3 Mt. Hawthorn performance data.

Parameter Inlet (to Filter) Outlet (to trench)

Nitrate mg/L 3.8 2.5

Phosphate mg/L 0.09 0.06

Suspended Solids mg/L 155 76

Total Dissolved Solids mg/L 0.9 0.9

pH 7.8 7.6

4.3 GRS tank system, Western Australia GRS Watersave tank system is comprised of three general components. The bathroom and laundry greywater is directed to a 1000 L sedimentation tank (essentially a septic tank intended to remove any settleable particulate material from the greywater). The settled greywater is then immediately sent to a distribution system that provides water to a small fruit tree orchard. It also employs an overflow system and a diverter, to allow the owner to divert greywater to and from the distribution system. There are many systems like this installed around WA. The maximum daily flow for this device is 400 L per day.

Table 4 GRS tank system performance data.

Parameter Inlet (to tank) Outlet (to trench) Nitrate mg/L 9.1 3.1 Phosphate mg/L 0.61 0.15 Suspended Solids mg/L 405 100 Total Dissolved Solids mg/L 1.0 1.2 PH 9.1 8

4.4 Double Tank System, Western Australia Laundry and bathroom greywater is first passed through two sequential 350L sedimentation tanks (to remove settleable particulate material) followed by interim storage consisting of three (3) 200 L tanks linked to also serve as a pump chamber. The greywater pumped from the three 200 L tanks is filtered through a 25 mm in-line filter and distributed to the ground by a dripper system.



Table 5 Double Tank System performance data.

Parameter Inlet (to tank) Outlet (pump tank) Dripper irrigation

Nitrate mg/L 3.3 3.0 1.7 Phosphate mg/L 1.93 1.63 0.66 Suspended Solids mg/L 310 195 20 Total Dissolved Solids mg/L 1.7 1.0 1.0 PH 10.3 8.9 8.2

4.5 Greymax, Western Australia This installation uses greywater from two neighbouring houses and feeds it to two lateral plastic lined trenches, one 20m by 1.2m and the other 25m by 1.2m. The trenches are filled with sand (85%) and mud (15%). The greywater passes through a collection tank prior to disposal in the trenches. This design is part of a larger permaculture design that has many other water conservation aspects. Data on this project has not been collected for several years. No data was available for this system. 4.6 Queensland, Australia A greywater system was built in a “healthy home” constructed on the Gold Coast in Queensland Australia (Gartner, 2004). The home uses storm water collected from the roof combined with greywater collected from the bathroom and laundry. The greywater is sent to a tank underneath the house. Inside that tank is an Envirotech Sandfilter that is dosed by a programmed flow controller to maximize contact time and treatment. After treatment the greywater is stored in another tank. Unfortunately at this point in time Queensland laws do not allow greywater reuse in a sewered area, and the treated effluent is disposed of along with the blackwater. As soon as laws allow for greywater reuse, the system will be upgraded to disinfect the greywater, and it will be used in toilets and for irrigation. About 80% potable water use reduction is expected from a full installation of this system and “significant reductions” have been observed in the healthy home. Chemical analysis has shown the sand filter to be effective in removing organic and suspended solids. The greywater system is reported to have a payback period of 100 years. The high power consumption and extremely long payback period indicates the greywater system is not justifiable from a strictly economic perspective. However, the designers believe they can improve the economics and the water conservation benefits offset the poor economics and that the water conservation benefits contribute to the sustainability of the technology.



Figure 9 Household greywater treatment system process overview. Gold Coast, Queensland

Australia.

4.7 Santa Barbara, California Greywater is collected from bath/shower drain, the bathroom sink and laundry. It is directly distributed throughout the yard to fruit trees, vegetable gardens and to low water consuming plants. The system uses gravity and does not filter or treat the greywater and requires no storage tank. The plumbing was designed and built with the eventual implementation of a greywater system in mind. Because of this, the cost of implementation was much lower. Since the owner did much of the work the labour costs were greatly reduced. The materials are reported to have cost $781 USD. The labour cost for plumbing was $350 USD. The irrigated area is divided into zones one (52 square feet) and two (44 square feet). One zone is irrigated for 2-3 weeks then the effluent is sent to the other zone for the same period of time. The system is expected to have a lifetime of 20 years. 4.8 East Bay, California Two sites were selected through a survey of 500 people for implementation of an experimental greywater system. The system employed a 1/2 horsepower submersible pump, a 55-gallon surge tank, a 50 pound sand filter, a subsurface drip system, a water meter and plumbing connections. The grey water systems each collected from two bathroom washbasins and two bath/shower drains and a laundry machine for use in irrigating a yard at one location and a shrub garden at the other. Each system cost about $1250 USD and labour cost for each was around $4150 USD. The labour costs were high due to the work involved in setting up the secondary piping system. The soil and gardens at each location were monitored and no noticeable negative impacts were noted.



The residents experienced no maintenance problems during the study, and both planned to keep the systems. They noted however that a significant financial incentive would have been required for them to purchase the system. http://www.oasisdesign.net/faq/SBebmudGWstudy.htm 4.9 Frankfurt, Germany At the Arabella-Sheraton, a four-star hotel in Frankfurt, a greywater system using an RBC was installed in 1996. With the parameters initially set at 90L of greywater per day, 50L toilet water used per guest, reported water costs of 4 EUR (CDN $6.25) per litre, and a 7% increase in water prices annually, the system paid for itself in approximately 6.5 years. Further information about the system was not disclosed. 4.10 Loughborough University, United Kingdom A lab scale greywater treatment system and a full sized greywater system for a university residence were constructed to examine the feasibility of greywater reuse at Loughborough University (Surendran, 2004). The lab-scale system had a capacity of 75 L and used four stages: 1) balancing flow and buffering peak mass loads, 2) solid separation and digestion 3) aerated bio-filter to remove organics, and 4) deep bed slow flow filtration to generate near potable quality. It operated for 200 days without any maintenance or disinfection. The full-scale system was built to flush toilets with greywater and rainwater for 33 students. The main system was based on the lab scale design with a few modifications. The set-up was changed eventually to incorporate a second system that served 6 of the 33 students to test out a variation of the original methods used. Project one used 16 wash basins, 2 baths, 2 showers and about 2/3 of the washing machine water for greywater reuse in 4 WCs. The design used a 1400L buried storage tank, a low-level storage tank and a loft storage tank (both 700L), and used aeration and filtration for treatment. The aeration used 2.4 L/min of coarse air bubbles. The tertiary treatment phase was a deep slow filter that used 100mm of 20 ppi foam over 700mm of 45 ppi foam cartridges. The system operated for approximately a year without problems. The following table outlines the data collected from the influent and effluent of both systems.



Figure 10 Amortization of a greywater system in a German hotel (Nolde, 2004)

Table 6 Final quality and removal efficiency of primary system (Surendran, 2004).

Parameter Influent SD* Effluent SD*

Ammonia Nitrogen mg/L 1.6 0.93 0.1 - 0.2 10.50

Total Coliforms cfu/100mL 160000 0.0 50.0 - 52.5 46.7

Total Suspended Solids mg/L 34.5 - 40.2 30.5 2.0 - 2.7 2.9

Total Dissolved Solids mg/L 364.0 - 379.7 82.4 335.8 - 356.6 133.7

BOD5 78.1 - 83.1 40.0 3.0 - 4.0 2.8

pH 7.3 - 7.4 0.2 7.6 0.2

* SD = Standard Deviation

Table 7 Final quality and removal efficiency of secondary system (Surendran, 2004).

Parameter Influent SD* Effluent SD*

Total Coliforms cfu/100mL 160000 0.0 50.0 – 64.7 47.7

Total Suspended Solids mg/L 24.0 – 28.9 14.6 1.5 – 1.9 2.01

Total Dissolved Solids mg/L 427.5 – 428.4 50.95 417.1 – 437.9 97.88

BOD5 60.5 - 43.46 1.8 – 2.0 1.26

pH 7.4 0.25 7.8 – 7.9 0.24

* SD = Standard Deviation



4.11 Eynesbury - Victoria, Australia A town of 3,000 people will be connected to a mixed-wastewater recycled water system. It will use a third pipe system that will provide water for flushing toilets, and watering gardens and public spaces. The water will be purified at the nearby Surbiton Purification Plant (Minister for Water, Minister for Environment Media Release August 13th 2004). The recycled water scheme is expected to reduce total drinking water demand by 50% in the area. The media release referenced did not provide additional information, but is useful in reflecting the high interest in water reuse in Australia. 4.12 Rouse Hill Development - Sydney, Australia The third stage of a $185 million (AUS) development that involves an extensive mixed-wastewater water reuse development scheme is underway in the Rouse Hill development in Sydney Australia (Judge, 2004). Approximately 10,000 new homes will be connected to a dual water supply system that will provide highly treated, recycled water for washing cars, watering gardens, flushing toilets, park and golf course irrigation and industry. Residents in this area were supplied with 1.350 million cubic metres of recycled water in the last financial year. The Rouse Hill system will have enough capacity for 36,000 homes in the region when it is complete. Final completion is scheduled for 2012. More information is available in the literature about the Rouse Hill development, but as ithe reuse system is not strictly greywater reuse this information is not presented here. One interesting note regarding the Rouse Hill development was a recent news article describing a cross-connection (connection with a source of domestic sewage) that occurred within the reuse water distribution system and resulted in contamination of the reuse water. This was investigated and found to be caused by an illegal plumbing connection within the development that was quickly identified and corrected by the authorities. 4.13 Casa del Agua (Tucson, Arizona) Casa del Agua is a Tucson residence that was retrofitted in 1985 with water-conserving fixtures and reuse technologies, and landscaped with drought tolerant plants. It is an occupied domestic residence that is also an educational project designed to facilitate research and to test domestic water use and conservation strategies, and is open to the public during scheduled hours. Compared to a typical Tucson home, municipal water consumption is reported to have achieved a 27% reduction in total water use and a 47% reduction in municipal water use as a result of the rainwater harvesting, greywater reuse, and desert-adapted landscaping with drip-irrigation and low-water-use fixtures used in the home (J. Am. Water Resour. Assoc., Vol. 37, no. 5, pp. 1237-1248. Oct 2001). The Casa del Agua greywater system drains greywater from the household's water-using appliances into a 55-gallon sump surge tank. A filter is fitted over the greywater drain line where it enters the sump to remove lint and hair before the water is pumped to other components



of the recycling system. The sump fills to a level that activates a float switch and then the greywater is pumped through an underground drip irrigation system to the landscape or for use in toilet flushing. Construction of the Casa del Agua's greywater treatment and distribution system was about US$1,500. The 5,000 gallon volume storage tank cost about US $2,500. http://ag.arizona.edu/AZWATER/arroyo/071rain.html

Photo 5 Casa del Agua demonstration project in Tucson, Arizona (from

http://www.csbe.org/Brittain/brittain_fig1.htm)

4.14 Quayside Village, North Vancouver, B.C. Quayside Village (QV) is a co-housing community located in the City of North Vancouver, British Columbia, which included a greywater recycling system in its design in cooperation with the North Shore Board of Health and the City, with financial support from the Canada Mortgage and Housing Corporation (CMHC). As a multi-agency supported demonstration project, Quayside’s greywater system had to be reviewed and discussed with a number of government agencies. The support of CMHC and the North Shore Board of Health has provided some degree of liability shelter for the City of North Vancouver in approving the project. However, municipal staff remained concerned about possible liability for water-related sickness. For this reason, only a very conservative system with many backup features was allowed, and the City would only allow the treated greywater to be reused to flush toilets. Treatment Process Description The wastewater treatment and reuse system, as initially installed included the following components:

1. Septic tank to remove coarse solids and grease/oil.



2. Biofilter (WaterlooTM) with recirculation back to the septic tank inlet.

3. Slow sand filter to remove solids.

4. Ozone generator and contact tank (currently replaced by chlorination).

5. Slow sand filter (automatically back-washed).

6. Storage tank Process Performance Although the system has been in operation for over three years, there are ongoing concerns about the (liability) risks involved in greywater recycling. While monitoring data indicates the water reuse system can meet the target water quality objectives, there have been a number of equipment failures that have interfered with being able to meet the regulatory operational for six continuous months. One of the key problems initially identified as the reliance of ozone as the sole means of disinfection, compounded by the lack of adequate ventilation of the ozone off-gas. A result of poor design, the ozone was allowed to off-gas from the storage tank directly into the enclosed equipment room. Changes to Improve Performance Following a recent independent process review, the following remedial measures were implemented to improve system performance and address the problems observed with the Quayside Village reuse water treatment system:

• The ozone generator and contact tank were removed and replaced with a chlorination system. This eliminates the problems with the ozone off-gas and provides a chlorine residual to control re-growth of bacteria.

• The cloth fabric was removed from the septic tank. The supplier intended the fabric to assist in removing colloidal particles; however, the structure supporting the fabric in the tank collapsed and blocked the outlet.

Lessons Learned System design and function should be resolved with municipality and authorities before equipment purchase and system setup, as conservative municipal response to risk can lead to minimal allowances and overbuilt systems. In the case of Quayside Village, the municipality and the local health authorities required the system to be overbuilt to compensate for perceived risk. The irony is that despite the lack of adequate engineering in the design of the overall treatment system (e.g. collapse of fabric in the septic tank, undersized septic tank, ozone off-gassing into an enclosed space, etc.) a number of the equipment failures and operational problems have resulted from using over-sized unit components with respect to the reuse water demand applications permitted by the municipality.



Figure 11 Quayside Village Water Reuse Treatment System

Before choosing any water reuse treatment equipment, project managers should talk extensively to manufacturers about the technical issues and process, mechanical, and electrical engineering input should be obtained to ensure the components are compatible and work as a system. Often early technology innovations are cobbled together from existing off-the-shelf unit process components without due regard for how they will function as an overall integrated process. Realistic timelines should also be negotiated and understood by the engineers, architects, project managers, residents, and municipal staff. Cost: The capital cost of the equipment was approximately $115,000, or $5,750 per unit. 4.15 Conservation Coop, Ottawa, Ontario Conservation Co-op is a four (4) story eighty-four (84) unit apartment building, located in the Sandy Hill district of the City of Ottawa, whose tenants are committed to provide "green" alternatives in an environmentally friendly building reducing the consumption of energy, water and waste to levels significantly lower than those of conventional households. Constructed in 1995, the project incorporates water conserving plumbing fixtures that resulted in a normalized water use per apartment of 390 L/day compared to a typical apartment water consumption of 530 L/day in the Ottawa area. The Research Division of CMHC arranged to have the bathrooms in eight of the 84 apartments constructed with dual plumbing systems. One plumbing system allowed the bathrooms to operate normally using municipal water and sewage piping. The other parallel plumbing system connected the drains from the bathtubs to a light greywater treatment system. This system

SepticTank

Ozonation Slow Sand

Filter

Biofilter

Storage

SEWER



receives water from the bathtubs, treats it and then reuses the treated effluent for use in the toilets of the eight apartments. Discussions were held with the Ministry and City officials to develop treatment criteria. The criterion for the design of the treatment system, outlined in Table 1, were established and accepted by the Regional Health Department on the understanding that this was an experimental system for water reuse; strictly for toilet flushing. Note that no consideration was given to the biochemical oxygen demand of the greywater.

Table 8 Water quality objectives for Conservation Coop greywater reuse system

Parameter Treatment Objectives

Total Suspended Solids (mg/L) 30

Escherichia Coliform (CFU/100 mL) 0

Turbidity (NTU) 20

Colour (TCU) 20

Iron (mg/L) 1

Manganese (mg/L) 0.5

The average daily water use was 640 L/day for toilet flushing, 1,300 L for bath/shower water and 700 L/day for other uses (there are no laundry facilities in individual apartments). A literature review of greywater treatment technologies as used to select two treatment options for a pilot-scale testing program: 1) slow sand filter; and 2) rapid sand filter. The pilot-scale study was not as successful as anticipated; however, the project proceeded with a greywater treatment process design based on a sand pressure-filter system. Treatment Process Description The greywater treatment system was completed and commissioned for use in August of 1999. It consisted of the following components:

1. Basket screens (1 mm mesh) to trap hair, lint and other large particles. Sodium hypochlorite pucks are placed in the screening baskets to control odours and filter biofouling.

2. Equalization (440 L) tanks to remove floatable oils, scum and settleable solids, as well as provide initial disinfection. Accumulated solids and scum are automatically discharged to sewer after each fill-draw cycle is complete.

3. Pump to transfer liquid from the equalization tanks through a multi-media pressure filter.



4. Upflow multi-media pressure automatic-backwash filter to remove particulate material. These types of filters are more commonly used in potable water treatment systems and do not remove BOD.

5. Ozone is added to the filtered water prior to discharge into a treated water tank.

6. Storage tank (600 L).

7. Distribution pump that is activated by a drop in pressure (toilet flushing) within the distribution system.

Process Performance By late September 1999 the filter media had to be replaced, and by mid-October one of the system pumps had failed and the system was down for two weeks until the pump could be replaced. A valve and pump failure in November shut the system down until early December 1999. By March 2000, the treatment system was shut down and the toilets to the eight units were once again connected to water from the city supply. This action was taken in response to extensive complaints from the residents of the eight apartment units regarding problems with odour and rapid scum accumulation in the toilets, and an incident in which ozone release from the treatment facility caused injury to the maintenance supervisor. An independent review of the treatment system noted the greywater had a significant biochemical oxygen demand (BOD5) of 130 mg/L that had not been taken into consideration in the treatment process design. No biological treatment had been provided for. As a consequence, the filtered greywater rapidly became anaerobic, producing the black foul-smelling reuse water that was being reused for flushing the toilets. Further, the toilets for the eight apartments were subjected to significant water-hammer effects as a result of the transfer pump and temporary nature of the pilot installation, resulting in loud banging noises and vibrations that were extremely disconcerting to the residents. The flow and pressure specifications of the pump was inadequate to meet the demands of more than one toilet flushing simultaneously, requiring the residents to flush their toilets repeatedly. The following remedial measures were recommended to improve system performance and address the problems observed with the Conservation Co-op reuse water treatment system:

• Add a biological treatment component to reduce the BOD concentration to less than 10 mg/L.

• Add a pressure tank to the distribution system to improve water supply to the toilets.

• Remove the ozone system and replace it with either a secondary chlorination or ultraviolet disinfection system.



Figure 12 Conservation Co-op Greywater Treatment System

Lessons Learned

The CMHC Conservation Co-op pilot project demonstrated that residential greywater reuse can save water and reduce the sewage and water demands on municipal systems. The project also demonstrated that significant operating and maintenance problems can be experienced with greywater reuse systems if wastewater characterization is not considered in the design, and appropriate components are not incorporated in the treatment system to remove BOD. Greywater must be treated if it is to be stored for any significant period of time, or if it is to be distributed through plumbing for any indoor application. Cost The system cost, (excluding pilot testing but including design, materials, installation, and commissioning, was reported to be $30,000, or $3,750 per unit, 4.16 Toronto Healthy House, Toronto, Ontario Project Background The Toronto Healthy House project was a result of a Canada-wide "Healthy Housing Design Competition" held by CMHC. The two side-by-side residences have no connection to the municipal water or sewage infrastructure, and are situated on small inner city lots (6 metres by 22 metres). The dwellings rely on rainwater harvesting for potable water, and reuse water for all other domestic water needs (i.e. toilet flushing, laundry, bath/showers, and irrigation). Water Reuse Treatment Process Descriptions Both blackwater and greywater are collected and treated for reuse as illustrated in Figure 12. The treatment process consists of the following components:

Coarse Screening

Storage Ozonation

Filtration



1. A 3000 L septic tank, which has been divided into two unequal (2/3-1/3) compartments. The first compartment is intended to remove coarse solids and grease, and the second is equipped with hanging filter cloths intended to remove colloidal solids.

2. Biofilter (WaterlooTM) with recirculation back to the septic tank inlet.

3. Roughing filter to remove coarse biosolids.

4. Slow sand filter to remove fine particles (both the roughing and slow-sand filters are automatically back-washed).

5. In-line ozone injection using a venture-style aspirator, followed by a contact tank.

6. Storage tank

The stored reuse water is used for toilet flushing, garden irrigation, laundry, and bathing/showering purposes. Any wastewater that is in excess of the reuse requirements of the household is discharged to a gravel bed in the front yard. The treated reuse is not subjected to further disinfection methods (e.g. chlorination) following ozone disinfection. A three-component filter (roughing filter, slow sand filter and activated carbon filter) was originally installed but has since been decommissioned and replaced with the separate roughing filter and slow sand filter due to problems experienced with filter clogging. Process Performance Online turbidity, flow, and water quality data for both the potable and reuse systems has been collected by an independent agency since November 2000. The online data is being collected and posted on a web site created for the project (http://healthyhousesystem.com) displaying turbidity and flow data recorded over the last 45 days and water flows for the last 24 hours.

Figure 13 Toronto Healthy House Water Reuse Treatment System

SepticTank

Dual MediaFilter

Roughing Filter

- Biofilter

Storage Ozonation



Water quality objectives for the reuse water systems are illustrated in Table 9. Analytical parameters monitored include: 1) Bacteriological (total coliforms, E. coli and background bacteria); and 2) Chemical for reuse (pH, nitrite/nitrate, BOD, TSS, TDS, sodium, chlorides, phosphate, and ammonia).

Table 9 Reuse Water Quality Objectives for Toronto Healthy House

Parameter Treatment Objectives

BOD (mg/L) < 10

TSS (mg/L) < 10

Total Coliform (c/100 mL) < 1

E. coli (c/100 mL) < 1

Turbidity (NTU) < 2

Although the reuse water quality BOD, TSS, and turbidity criteria have been consistently met, the total coliform bacteria criteria have not been met at times, and heterotrophic plate counts are elevated, indicating bacterial regrowth in the reuse storage tank and distribution system. Regrowth can include “opportunistic pathogens” such as strains of Psuedomonas aeruginosa, Acinetobacter spp., Aeromonas spp., , etc. The potential for regrowth is of particular concern where the water is being sprayed and potentially inhaled, as in the case of using potable water or reuse water for showers. Strains of Klebsiella pneumoniae, and Legionella pneumophila if inhaled as aerosols can cause severe illness. Water temperatures of 30 to 50 oC are favorable to the growth of Legionella. Another concern with the existing treatment system was that ozone was being released into the residence, and may pose a health hazard to the occupants. Changes to Improve Performance As a result of the independent process review, the following remedial measures were recommended to improve system performance and address the problems observed with the Toronto Healthy House reuse water treatment system:

• An ozone sensor and alarm should be installed, and consideration given to modifying the ventilation of the equipment space to ensure the ozone is destroyed and the gas is ventilated outside of the structure.

• Either a secondary chlorination or ultraviolet disinfection should be added to both the potable and reuse water treatment systems to inhibit bacterial regrowth within the storage and distribution systems. The Provincial health agency would prefer to have a minimum 1 mg/L chlorine residual maintained within the distribution system.



Lessons Learned The CMHC Toronto Healthy House residential project demonstrates reuse water treatment can be done within a family residential dwelling setting, with reuse applications including toilet flushing, bathing/showers, laundry and irrigation. Although the project was designed to treat mixed wastewater (greywater and blackwater) instead of only greywater, it does demonstrate that a high level of reuse water quality in terms of BOD, TSS and turbidity can be consistently met treating either greywater or blackwater. Bacterial water quality objectives have not been reliably met, however, suggesting alternative disinfection methods are needed. Careful consideration must be given to ensure that ozone used in a residential application is properly ventilated, and that consideration is given to controlling regrowth of bacteria within the storage and distribution systems. One method of achieving this is to maintain an adequate residual chlorine level within the treated water storage tank. 4.17 Charles Sturt University Thurgoona Campus Thurgoona campus is located 10 km outside Albury, New South Wales, and houses the university’s School of Environmental and Information Sciences and the School of Business and comprises research and teaching facilities, academic and administrative offices, residential accommodation and a regional herbarium. The water management system incorporates dry composting toilets, a greywater system, rainwater tanks and stormwater harvesting, with an overall objective of minimizing potable water consumption. Greywater is collected from hand basins, showers, kitchen sinks and the small amount of seepage from the composting toilets. The treatment train typically consists of two (2) intermittently loaded wetlands, an evaporation mound and an ephemeral wetland for overflow in wet periods. The greywater reuse water is used for sub-surface irrigation and clothes washing in residences. (Australian Water Conservation and Reuse Research Program – Integrated Urban Water Management. Australian Water Association CMIT-2004-075 April 2004) 4.18 Inkerman Oasis, Melbourne, Victoria Inkerman Oasis is a 236 apartment, multi-level residential redevelopment site located in the inner city suburb of St Kilda, and includes a combined greywater and stormwater recycling system. Bathroom greywater from about half of the units is treated on-site, in combination with the first flush of stormwater run-off from across the development. This combined greywater and first-flush stormwater is used for flushing toilets flushing and sub-surface landscape and garden irrigation. Excess treated greywater is directed into the sewer system. It is estimated the greywater and stormwater reuse system saves the development up to 40% in potable water demand, in addition to reducing wastewater and stormwater flows from the development. Other benefits include reduced nitrogen and phosphorous entering Port Phillip Bay, and reduced landscape and garden fertilizer usage.



One of the problems faced by the development has been slow approvals and the project has demonstrated that the lack of industry and authority experience and policy frameworks will increase the length of time associated with gaining approvals, and this should be factored into the development process (Australian Water Conservation and Reuse Research Program – Integrated Urban Water Management. Australian Water Association CMIT-2004-075 April 2004) 4.19 20 River Terrace - The Solaire Building, New York The Solaire Building is a 27-story high-rise, apartment building located in lower Manhattan that was rated as one of the top ten “Green Buildings” for 2004 by the American Institute of Architects (AIA), and has received a LEED Rating of Gold from the U.S. green buildings Council. A wastewater treatment and recycling system was installed in the basement of the building. This system treats wastewater generated in the building and uses it for toilet flushing, cooling tower make-up water, and subsurface irrigation of an adjacent park (www.batteryparkcity.org - follow the prompts to 20 River Terrace). The treatment facility produces a high quality effluent with CBOD less than 8 mg/l, TSS less than 2 mg/l and turbidity less than 0.2 NTU, and is now being designed into other buildings in the Battery Park City complex. (Gaines & Zavoda, 2004) 4.20 Gillette Stadium, Foxboro, MA The Gillette Stadium (home of the New England Patriots) incorporates a large recreational water reuse systems to meet the water demands associated with a 68,000-seat stadium (Gaines & Zavoda, 2004). The treatment and reuse system includes the following components:

• 250,000 gal/day Membrane Bioreactor facility capable of being expanded to treat 1.1 MGD;

• 680,000 glass-lined equalization tank to capture the half-time wastewater surge;

• 2.4 acre ground water recharge field for the excess reuse water;

• 500,000 gallon elevated water tank for reclaimed water storage.

4.21 Australian Greywater System Cost Experience Table 10 illustrates system materials, costs, and energy & maintenance requirements for a range of greywater reuse approaches based on experience in Australia. The amounts shown in the table are in Australian dollars, which is fairly close to Canadian currency at the time of writing. The reductions in water consumption resulting observed in Australian case studies is illustrated in Table 10.



Chlorine Feed

500,000GallonRecycle

Storage Tank

Leach Beds 300GPM

(250,000 GPD)

Flow Meter(Typ.)

SamplingLocation (Typ.)

Flow SplitterBox

1,000,000GallonPotableWaterTank

A/B

A/B

Emergency Interconnect(Backflow Protected)

68,000 SeatStadium

A/B

Lift Station

680,000Gallon

EqualizationTank

250,000 GPDWWTP

High Service Pumps(300 GPM)

Dosing Pumps(300 GPM)

A/BA/B

A/BA/B

12"

8"

8"

16" Recycle Water(3200 GPM)

4" Dosing(150 - 300 GPM)

16" Recycle Water (3200 GPM)8 Recycle Water(150 - 300 GPM)

Recycle DrainMin. 2500 GPDMax. 640,000

GPD

16" Force Main (3500 GPD)

4" Low Flow Force Main (150 GPD)

Figure 14 Gillette Stadium Water Reuse System Flow Diagram



Table 10 Greywater system materials, costs, energy and maintenance requirements {AUS $} (from Australian Water Association CSIRO, April 2004)

Table 11 Greywater system water savings (from Australian Water Association CSIRO, April 2004)



5 BC REGULATIONS AFFECTING GREYWATER REUSE British Columbia has two primary regulations, under two separate Acts, that deal with residential wastewater issues, but only one has provision for water reuse system, specifically (the new Sewage System Regulation does have provision for shallow sub-surface applications - although not specifically in reference to reuse water). 5.1 Health Act – Sewerage System Regulation The Health Act Sewerage System Regulation (B.C. Reg. 326/2004 - O.C. 701/2004), will be effective on May 31, 2005, addresses treatment and disposal criteria for sewage originating from single family dwellings to subdivisions with flows less than 22,700 litres per day discharging to ground. The Regulation is silent on the issue of greywater systems or water reuse, but does define “the discharge of domestic sewage or effluent onto land” as a “health hazard” unless “authorized under another enactment” {Section 3(2)}. The Regulation also defines “sewage” as being both greywater and blackwater combined). The Sewerage System Regulation does not address the practice of water reuse, or more specifically greywater reuse within a residence and the Ministry's perspective (J. Rowse, person. communication) is that greywater or mixed-wastewater reuse applications within a single family residence would not be of concern to the Ministry. However, greywater reuse systems that would affect a number of residences (e.g. Quayside Village) would be of concern to the Ministry. 5.2 British Columbia Building Code – Non-Potable Water Systems The Canada Mortgage and Housing report titled “Regulatory Barriers to Onsite Water Reuse” notes that while the “National Plumbing Code provides for alternative systems such as dual water distribution within sites” it also “prohibits the discharge of non-potable water through outlets such as faucets or toilets”. The BC Building Code also provides for non-potable water systems, and restricts outlets where they can discharge into “a sink or lavatory” (toilet). 5.3 Waste Management Act – Municipal Sewage Regulation (MSR) The only regulation in BC that does address the issue of reclaimed water, and inherently greywater reuse, is the Waste Management Act - Municipal Sewage Regulation (MSR). The MSR describe the conditions to permit reclaimed water to be used for a range of application. The conditions include a minimum effluent quality criteria, the completion of an environmental impact assessment and operations plan, treatment system component redundancy, and the posting of financial security for operations and a capital replacement fund. The MSR reclaimed water requirements apply only to discharges from two or more dwellings, and domestic sewage or treated effluent discharges originating from a single residence or dwelling is exempt from the provisions of the MSR.



Table 8 illustrates the effluent quality requirements as they are related to reclaimed water applications for treated wastewater. Parameters of concern are pH, BOD, TSS, turbidity and fecal coliform.

Table 12 BC Waste Management Act – Municipal Sewage Regulation – Reclaimed Water Criteria

Effluent Quality Requirements Class Reuse Application Median FC

(CFU/100ml) BOD

(mg/L) TSS

(mg/L) pH

(90%) Turbidity

(NTU) Urban: Parks, playgrounds, cemeteries, golf courses, road right of ways, school grounds, residential lawns, green belts, vehicle and driveway washing, landscaping, toilet flushing, outside fire protection, street cleaning Agricultural:

Aquaculture, food crops eaten raw, orchards and vineyards, pasture, frost protection, seed crops

Recreational:

Unr

estr

icte

d pu

blic

acc

ess

Stream augmentation, impoundments for boating and fishing, snow making

< 2.2 <10 < 5 6-9 < 2

Res

tric

ted

Pub

lic A

cces

s • Urban/Recreational: • Landscape Impoundments • Landscape Waterfalls • Snow Making (not for skiing and

snowboarding)

< 200 < 45 < 45 6-9 -

Monitoring Requirements (unrestricted access) daily (1) weekly daily weekly continuous

British Columbia Ministry of Environment, Lands and Parks. (1999). “Regulation 129/99. Waste Management Act Municipal Sewage Regulation.”

5.4 Discussion Greywater reuse for a single residence (i.e. an onsite system) is not covered under the Waste Management Act. Greywater reuse for surface irrigation for a single residence is not permissible under the Health Act as it is defined as a “health hazard” under section 3(2) of the Sewerage System Regulation. Greywater reuse for toilet flushing in general is not permissible as “an outlet from a non-potable water system shall not be located where it can discharge into … a) a sink or lavatory”. Consequently, the only greywater application that appears to be permissible for a single family residence in British Columbia is where the discharge is to ground and where such a discharge complies with the requirements of the Health Act - Sewerage System Regulation (i.e. the new Sewage System Regulation does have provision for shallow sub-surface irrigation applications).



Greywater reuse is permissible for two or more dwellings implementing a collective greywater reuse system, as long as the system complies with requirements specified under the Waste Management Act Municipal Sewage Regulation including: the completion of an environmental impact assessment and operations plan, effluent quality criteria, system component redundancy, and the posting of financial security for capital and operating costs or registration under an approved assurance plan (for private systems). A further regulatory complication for using greywater for flushing toilets within a single-family dwelling or multi-family complex, is the National Plumbing Code, which “prohibits the discharge of non-potable water through outlets such as faucets or toilets”.



6 ECONOMICS 6.1 Costs The two key capital cost components for greywater systems are for treatment and dual plumbing. The costs of treatment for a new single dwelling residential source would be expected to range from $750 for the supply and installation of a simple diversion device to about $10,000 for the supply and installation of a biological treatment system (regardless of the technology selected), plus the cost of providing a dual plumbing system for the reuse water. As residential units are clustered together, the cost for biological greywater treatment per residential unit will drop to about $3,000 per residential for a cluster of 100 homes. This doesn’t include the cost of community-based collection or reuse water pipe distribution systems. The costs of installing or retrofitting a residence for dual plumbing is site specific. However, the rough-in plumbing cost for a 2400 square foot residence with two bathrooms, kitchen and laundry facilities is approximately $6,000 to $7,000. It can be expected that the costs of installing similar non-potable plumbing would cost up to 50% more due to the lack of familiarity of the plumbing industry, need for techncial guidance, and provincial and municipal regulatory concerns, resulting in a plumbing installation cost of about $10,000 per household. Retrofit costs could be in the order of up to 2.5 times that amount, or up to $25,000 per household. With respect to retrofitting existing residences, greywater systems cannot be retro-fitted to houses on concrete slabs or some multi-storey buildings because there is no access to the separate pipes from the laundry or bathroom. It is likely that in many cases the installation of a secondary treatment plant may either be impractical or physically impossible because of access or land area for effluent application once consideration is given to setback distances, drainage and other site constraints. In addition to the cost of the treatment and distribution system, some form of greywater irrigation or subsurface disposal system will have to be constructed if irrigation applications are to be considered, with a capital cost estimated at from $5,000 to $10,000. 6.2 Economic Analysis Table 13 illustrates water consumption characteristics for the CRD (CRD water services website).

Table 13 Statistical data on water use in the CRD (CRD Website, 2004)

Average Daily Per-capita Demand all uses: 538 litres (118 gallons)

Average Daily Per-capita Residential Demand: 380 litres (84 gallons)

Average Winter Daily Per-capita Demand all uses: 400 litres (88 gallons)

Average Winter Daily Per-capita residential Demand: 281 litres (62 gallons)

Maximum Daily Demand: 318,000 m3 (70 million gallons)

Minimum Daily Demand: 114,000 m3 (25 million gallons)



Grey water re-use is an effective way of decreasing water costs and consumption from a municipal point of view, without decreasing net water use in a household. Based on the water consumption data in Table 13, and assuming an average of three persons per household, the annual residential water demand within the CRD is approximately 420 m3 per household (380 L/c/d x 3 persons x 365 = 416 m3). Considering proportional residential water consumption characteristics shown in Figure 1 and Table 14, from 20% to 40% of the residential water consumption could be used for toilet flushing, with CRD data indicating an average of 32%. By flushing with reuse greywater, this could save approximately 134 m3 (32%) per year per household in domestic water. Considering the water charge structure within the CRD shown in Table 15, and using an upper cost of $1/ m3, this could result in a savings of about $134 per year per household.

Table 14 Estimates of domestic water use for typical Australian households in comparison to the CRD.

Facility National 1 Queensland2, Sydney Water2 Western Australia2 CRD3 Toilet 110 (26%) 186 (32%) 100 (20%) 139 (32%) Handbasin 28 Bat/Shower 145 193 160 95 Kitchen 44 7 Laundry 110 135 130 112 Taps/Other 65 110 81 Total per Household 430 586 500 434 Notes: 1 - From GWA (2003) 2 - Jeppersen & Solley (1994) cited in QLd DNR&M (2003) 3 - Personal communication J. Hull (CRD)

Table 15: Water charges within the CRD (CRD website)

Location Fixed Charge1 Water Charge

Saanich $33.60 per annum $0.6225/m3

Victoria/Esquimalt $84.15 per annum $0.513/m3

Oak Bay $114.41 per annum $0.4237/m3

Central Saanich* $118.20 per annum $0.5948/m3

Sidney $97 parcel tax $0.9987/m3

North Saanich $187 parcel tax $0.7678/m3

Western Communities $26.76 per annum $1.0128 per m3

Considering the high cost of supplying and installing greywater systems plus the cost of operations and maintenance, and the characteristically low cost of potable water supply, it is unlikely that there will be an economic payback for water savings that would justify the capital expenditure. Where the cost of water reflects also the costs of wastewater treatment, the economics will be more favourable.



For greywater to have any value for recycling (toilet flushing, surface irrigation or subsurface drip irrigation) the treatment must be to secondary standard and chlorinated. The minimum cost of an aerated biological wastewater treatment system, with dual plumbing, is expected to be in the order of $20,000. As described above, the potential savings per household from greywater use for flushing toilets is in the order of $134 per year. Any savings in purchasing potable water must be offset against the cost of the treatment system over, say, 10 years, in addition to the cost for operations and mainternance. Assuming a 10-year investment period, a recycling system that costs more than about $1000 will not be economical in comparison to the estimated capital cost of up to $20,000. Water prices would have to rise up to $20 per m3 before secondary treatment of greywater could be justifiable on a strictly economic basis for some houses. Where the greywater reuse system is reducing wastewater flows to a community colection and treatment system, the cost savings or value of increased capacity to serve a greater number of homes needs to be factored into the economics. Again this is site specific, but it is worthwhile to note that the economic considerations should take into consideration the cost benefits of reduced wastewater flows to centralized collection and treatment infrastructure, reduced community potable water demands, in addition to any social benefits that may be realized through sustainability considerations (e.g. greater awareness with respect to water conservation). With respect to retrofitting existing residences, greywater systems cannot be retro-fitted to houses on concrete slabs or some multi-storey buildings because there is no access to the separate pipes from the laundry or bathroom. It is likely that in many cases the installation of a secondary treatment plant may either be impractical or physically impossible because of access or land area for effluent application once consideration is given to setback distances, drainage and other site constraints. A communal collection and treatment system may offer economies of scale to reduce the overall cost and improve the economics (as demonstrated in Figure 15), and creates a reuse water product that can be sold to large consumers. There is an example of this in the case studies section (see Frankfurt, Germany).

Figure 15 Cost of treatment, transport and total cost vs number of connections (Booker, 2000)



7 SUMMARY The following sections provide a brief summary of the information presented in this document pertaining to the specific components of greywater reuse posed by the Capital Regional District (see Section 1.2). 7.1 Greywater Definition Greywater is domestic wastewater excluding discharges from toilets and urinals. It can be sub-divided into two categories based on the level of contaminants present: 1) light-greywater; and 2) dark greywater. Light-greywater typically originates from bathroom tubs, showers, and sinks, in addition to laundry wash-water. Dark-greywater usually refers to kitchen sink drainage that often contains substantial quantities of organic materials and grease & oil. Regardless of the source, domestic greywater contains the same contaminants as blackwater discharges from toilets and urinals including soluble and particulate organic material, and pathogenic micro-organisms, although the level of contamination (concentration) is expected to vary depending n the source. The organic contaminants must be biologically treated and removed if the greywater is to be stored for any significant period of time, and the technologies used to treat greywater and blackwater sources are the same, typically incorporating some form of aerobic biological treatment and disinfection unit processes. Because the level of organic and pathogenic micro-organism contamination in light-greywater (such as that originating from bathroom sinks) is characteristically low, it is typically possible to divert this water directly for use in subsurface irrigation with only a minor level of treatment such as solids settling and filtration. Care should be taken to limit the contamination of greywater with inappropriate contaminants such as might be contributed by heavily soiled or bloodstained clothes, diapers, etc. Chemicals such as bleach, cleaning agents, paints, etc should not be disposed of into the greywater system, nor should any substance that may cause blockage, or detrimentally affect the plants to be irrigated with the greywater. Detergents may have a detrimental affect on some plants because of their sodium content and may require occasional irrigation with potable water. Alternatively, environmentally friendly soaps (e.g. made of potassium or magnesium compounds) can be used to minimize the amount of sodium applied to the plants. Considering the effects of the high season rainfall along the west coast in washing these salts from the soil, this may not be a problem. 7.2 Current Regulatory Environment for Greywater Reuse in B.C. The Waste Management Act Municipal Sewage Regulation (MSR) has provisions for reclaimed water reuse, which includes greywater systems. With respect to reclaimed water use, the MSR applies only to sewage or reuse water applications for clusters of two or more dwellings. The MSR includes specific requirements for environmental impact assessment, operations plans, security (100% capital replacement & operations security funds) and technology (system redundancy and chemical flocculation & filtration) and operations specifications (operator certification, sampling, monitoring & reporting) that may be onerous for small private systems



and make greywater reuse impractical. Furthermore, all reclaimed water systems must also have the written approval from the Ministry of Health. With respect individual residential (onsite) applications, the current regulatory environment in British Columbia is a barrier for greywater reuse. Because individual dwellings are exempt from the MSR, they fall under the jurisdiction of the Ministry of Health through the Sewerage System Regulation, and discharges from individual residences must conform to the ground disposal requirements of the Regulation (the Regulation does not specifically address the issue of greywater or water reuse). Although greywater reuse applications within a single residence would not typically be of concern to the Ministry of Health, the restrictions within the B.C. Building Code for Non-Potable Water Systems prohibit the location of an outlet for a non-potable water system where it can discharge into “a sink or lavatory” (toilet). 7.3 Options For Use of Greywater & Level of Treatment Required Greywater reuse applications include surface and subsurface landscape or garden irrigation, toilet and urinal flushing, bathing & showering, car washing, landscape impoundments etc. With the exception of the direct discharge of light-greywater to subsurface landscape irrigation applications (requiring a nominal level of filtration for treatment) or toilet/urinal flushing, most other applications require aerobic biological treatment and disinfection particularly where the treated greywater is to be stored for any significant length of time. Left untreated, stored greywater will quickly become septic and generate noxious odours. Furthermore, pathogenic microorganisms in the greywater must be removed through disinfection where there is potential for direct public (human) contact. 7.4 Components of Greywater Reuse Systems A number of issues need to be taken into consideration when reusing greywater. The system should be as simple and easy to use and maintain as possible. The system also should minimize risks to human health, either by providing for adequate treatment of the greywater, or by minimizing the chance of direct contact with humans. The system also should minimize the risks to plants, which may arise from some of the contaminants in the greywater such as from chemicals contained in soaps or detergents (e.g. boron, bleach, and sodium), which could adversely affect plant health. The primary components for greywater reuse system intended to generate reuse water for surface irrigation or indoor useage with potential for human contact include:

1. filters to remove hair, lint and coarse solids particles;

2. sedimentation tanks to separate and remove grease, oils & settleable solids from the greywater;

3. aerobic biological treatment to remove soluble organic contaminants;

4. final clarification or filtration to remove solid particles and bacteria generated during biological treatment;

5. disinfection to remove pathogenic (disease causing) micro-organisms;



6. reuse water storage tank.

While many direct diversion greywater systems provide some form of filtration, full biological treatment is needed if the greywater is to be stored for any significant period of time or is likely to come into direct contact with humans. However, if greywater is to used for subsurface irrigation or is to be used for other applications where it is unlikely to come in contact with humans (i.e. toilet or urinal flushing), and does not require extended storage - then coarse filtering to removal hair & debris or conventional septic tank treatment to remove grease/oil/scum/settleable-solids may be adequate treatment. Relatively clean greywater needs little treatment if it is to be used directly to irrigate landscape vegetation via a sub-surface irrigation system. Greywater containing lint, hair, or other solid material may clog the irrigation system, and a simple filter may be required. If there is a chance of a sudden release of greywater (for example from a bath being drained, or a washing machine being emptied), then a small surge tank should be considered to handle the surges and avoid ponding on the soil surface. The types of technologies required to aerobically biologically treat greywater are identical to those used for domestic wastewater treatment, and may be based on either suspended growth (e.g. activated sludge) or fixed film (e.g. RBC) aerobic biological treatment technologies. A method of diverting the greywater to the sewer system or septic tank should also be provided in case of an accidental release of harmful substances (bleach, etc.) into the greywater system, or a malfunction of a treatment system. 7.5 Complexity of Greywater Systems. Greywater diversion and filtration systems applied to direct-use subsurface irrigation applications are relatively simple in concept and to operate and maintain. Biological treatment components can add a significant degree of complexity to the greywater systems, depending on the type of treatment technology selected. Natural treatment systems such as wetlands or composting systems typically require comparatively less knowledge and skill to operate and maintain than activated sludge treatment systems. However, the latter typically offer a greater degree of operational flexibility in being able to adapt to variable greywater conditions (e.g. strength & flow) and often have a smaller footprint or area requirement. The level of complexity is comparable to equivalent treatment systems designed to treat mixed (grey & black-water) wastewater. 7.6 Technical Skills Needed to Operate Greywater Systems All greywater systems require plumbing skills to install, and depending on the type of treatment may require an electrical contractor as well. Filtration systems used in direct diversion subsurface irrigation applications can generally be serviced by a homeowner, and typically involves periodically cleaning a filter screen. More complex aerobic biological treatment systems typically require plumbing and electrical skill sets, as well as some basic knowledge of



biological treatment typically covered in an operator-training program. Often this maintenance is contracted to the equipment supplier with scheduled inspection/maintenance intervals of once every six months. Regardless of complexity, all systems should have written operating instructions that detail operations and maintenance information, in addition to providing specifications on all mechanical and electrical equipment components. 7.7 Greywater Reuse System Capital & Operating Costs - Existing Buildings & New

Construction. The two key capital cost components for residential greywater systems are for treatment and dual plumbing. The costs of treatment for a new single dwelling residential source would be expected to range from $750 for the supply and installation of a simple diversion device to about $10,000 for the supply and installation of a basic biological treatment system (regardless of the technology selected), plus up to $10,000 to install a dual (non-potable) plumbing system. The costs of retrofitting an existing residence with respect to plumbing is site specific but is expected to be up to $25,000 for an average single family dwelling. In addition to the cost of the treatment and distribution system, some form of greywater irrigation or subsurface disposal system will may to be constructed (unless discharge to sewer is possible), with a capital cost estimated at from $5,000 to $10,000 depending on the system selected. As residential units are clustered together, the cost for biological greywater treatment per residential unit will drop to about $3,000 per residential for a cluster of 100 homes. This doesn’t include the cost of community-based collection or reuse water pipe distribution systems. 7.8 Economics of Greywater Reuse Considering the high cost of supplying and installing greywater systems, and the characteristically low cost of potable water supply, it is unlikely that there will be an economic payback for water savings that would justify the capital expenditure. Where the cost of water reflects also the costs of wastewater treatment, the economics will be more favourable. For greywater to have any value for recycling (toilet flushing, surface irrigation or subsurface drip irrigation) the treatment must be to secondary standard and chlorinated. The minimum cost of an aerated biological wastewater treatment system could be up to $10,000, and combined with dual plumbing costs could result in an overall capital cost of up to $20,000. Any savings in purchasing potable water must be offset against the cost of the treatment system over, say, 10 years, in addition to operating and maintenance costs over that time. However, with an estimated economic benefit of $134 per year as a result of reduced potable water demand, a recycling system that costs more than about $1000 will not be economical (taking into consideration nominal operating and maintenance costs over that period. Water prices would have to rise up to $20 per m3 before secondary treatment of greywater could be justifiable on a strictly economic basis.



BIBLIOGRAPHY

Australian Water Association & CSIRO. 2004. Innovation in on-site domestic water management systems in Australia: A review of rainwater, greywater, stormwater and wastewater utilization techniques. CSIRO MIT Technical Report 2004-073. April 2004. Booker, N. (1999) Estimating the economies of scale of greywater reuse systems, Program report FE-88, CSIRO Molecular Science. Brennen, M. and R. Patterson. 2004. Economic analysis of greywater recycling. British Columbia Ministry of Environment, Lands and Parks. (1999). “Regulation 129/99. Waste Management Act Municipal Sewage Regulation.” Victoria, British Columbia http://www.qp.gov.bc.ca/statreg/reg/W/WasteMgmt/129_99.htm British Columbia Ministry of Health (2004). “Regulation 326/2004. Health Act: Sewerage System Regulation”. Victoria, British Columbia http://www.qp.gov.bc.ca/statreg/reg/H/Health/326_2004.htm British Columbia Ministry of Health (1985). “Regulation 411/. Health Act: Sewage Disposal Regulation”. Victoria, British Columbia http://www.qp.gov.bc.ca/statreg/reg/H/Health/411_85.htm Canada Mortgage and Housing Corporation. 1998. “Regulatory Barriers to On-site Water Reuse” Technical Series 98-101. CSIRO. 2004. The Economics of Water: Taking Full Account of First Use, Reuse and Return to the Environment. Folio No. S/031474. March 2004. Diaper, Clare., April 2004. Innovation in on-site domestic water management systems in Australia: A review of rainwater, greywater, stormwater and wastewater utilisation techniques. CSIRO MIT Technical Report 2004-073. 31pp. Dillon, Peter. 2000. Water Reuse in Australia: Current Status, Projections, and Research. Water Recycling Australia 2000. Adelaide, 19-20 Oct 2000. pp. 99-104. Dyck, E. “Greywater”, Onsite Sewage Disposal, No. 9, Spring 2001 Gaines, F., and M. Zavoda. 2004. “Reuse of treated wastewater”, NOWRA Water Reclamation, Recycling and Reuse Seminar, Nov. 2004. Gruvberger, C. et al. “Sustainability concept for a newly built urban area in Malmö Sweden”, Water Science and Technology, Vol. 47, No. 7-8, 33-39. IWA Publishing, 2003. Gray, S. and Bookner, N. “Wastewater Services for Small Communities”. Water Science and Technology, Vol 47, No. 7-8, 33-39. IWA Publishing, 2003.



Gartner, T. QLD Dept of Natural Resources, “Water Case Studies - Healthy Home” Australian Greenhouse Office, Queensland Australia, 2004 http://www.greenhouse.gov.au/yourhome/technical/fs26.htm GWA. 2003. A Mandatory Water Efficiency Labelling Scheme for Australia. Final report prepared for Environment Australia by George Wilkenfeld & Associates. Sydney. Kambanellas, PhD, C.A. “Recycling grey water in Cyprus”, 6th specialist Conference on Small Water & Wastewater Systems & 1st International conference on Onsite Waste Water Treatment & Recycling, 11-13 February 2004, Western Australia. Lopez Zavala, M.A. Funamizu, N. Tatakuwa, T. “Onsite wastewater differential system: modeling approach”. Water Science and Technology, Vol. 46, No. 6-7, 317-324. IWA Publishing 2002. Mars, R. “Case Studies of Greywater Recycling in Western Australia” ”, 6th specialist Conference on Small Water & Wastewater Systems & 1st International conference on Onsite Waste Water Treatment & Recycling, 11-13 February 2004, Western Australia. Media Release: Judge, C. “Recycled water for 10,000 new homes”, 09 August 2004, http://www.sydneywater.com.au/WhoWeAre/MediaCentre/MediaView.cfm?ID=235 Media Release: Minister of Water, Minister of Environment, Victoria, Australia “NEW TOWN TO BE FULLY CONNECTED TO RECYCLED WATER”, August 13th [email protected] Nolde, E. “Greywater Recycling Systems in Germany – Results and Guidelines”, 6th specialist Conference on Small Water & Wastewater Systems & 1st International conference on Onsite Waste Water Treatment & Recycling, 11-13 February 2004, Western Australia. National Resources Defense Council and the Pacific Institute. 2004. Energy Down the Drain – The Hidden Costs of California’s Water Supply. August 2004. 79 pp. Ottosoin, J. and Stenström, T.A. “Faecal contamination and associated microbial risks”. Water Research, Vol. 37 (2003) 645 – 655. IWA Publishing 2003. PriceWaterhouseCoopers. 2000. Economic Aspects of Water Recycling in Queensland.. April 2000. Queensland Government Environmental Protection Agency. 2001. Recent Advances in Water Recycling Technologies. A.I. Schäfer, T.D. Waite, P.Sherman (Eds.) Surendran, S. “Performance of on-sight Greywater Reclamation Systems.” , 6th specialist Conference on Small Water & Wastewater Systems & 1st International conference on Onsite Waste Water Treatment & Recycling, 11-13 February 2004, Western Australia.



West, S. M. 2003. On-site and Decentralised Sewage Treatment Reuse and Management Systems in Northern Europe & the USA - Report of a study tour - February to November 2000. 104pp. GREYWATER TREATMENT TECHNOLOGY WEBSITES http://www.ecologicalhomes.com.au/wastewater_systems.htm http://www.electropure.com.au/products/pro3_dbk200.html http://www.clivusmultrum.com/greywater.html http://www.envirosink.com/about.html http://www.greywatersaver.com/contact.htm http://www.aquaclarus.com/prod_sim_how.htm http://www.nature-loo.com.au/greywater/natureclear/natureclear.html http://www.biolytix.com/filtration http://www.copa.co.uk/products/mbr/default.asp http://www.greywater.com/e_s2_konzept.html http://www.electropure.com.au/techinfo/index.html



APPENDICES



System Name Greywater Saver Level of Treatment Primary - Filtration - Sub-surface Irrigation Diverter Valve - recycles laundry and bathroom water for garden irrigation. The Greywater Saver has a manual gate valve, which users can open or close to select whether their greywater is diverted for garden irrigation or disposed to the sewer or onsite wastewater system. It includes a removable stainless steel mesh filter basket to filter out larger particles from the greywater such as lint and hair. Removal of the stainless steel mesh filter for regular cleaning is done by the homeowner. Filtered greywater flows under gravity from the diverter vessel through a 50mm diameter pipe to piped irrigation trenches (90mm pipe with 20mm holes surrounded by rock aggregate) located just beneath the surface of garden beds. A flow splitter (Greywater Saver Flow Splitter - 50mm diameter Y junction fittings) is used to disrtribute the greywater uniformly to the trenches. The fittings split a single stream of filtered greywater under gravity into two equal volume streams that in-turn may each be further split into two streams as might be needed for a particular garden’s layout. This gravity Y junction irrigation arrangement is typically referenced in the greywater literature as a "branched drain". http://www.greywatersaver.com/greywatersaveruse.htm System Name Clivus Multrum Greywater System Level of Treatment Primary - No Treatment - Sub-surface Irrigation

The Clivus Greywater Irrigation System is a simple method of using greywater for plant irrigation. It consists of a dosing basin, effluent pump, water level controls, and covered irrigation troughs. There are no filters to clog, clean or change. As greywater flows into the dosing basin, level controls in the dosing basin engage the effluent pump to fill irrigation troughs. http://www.clivusmultrum.com/greywater.html System Name Electropure Level of Treatment Physical/Chemical In the electropure system, an electric current is applied to to electrodes inside a tank. Metal ions released from the electrodes precipitate contaminants from solution. Gas bubbles released during the process float these metal precipitates to the surface where they are removed. http://www.electropure.com.au/techinfo/index.html System Name Aquaclarus Level of Treatment Biological secondary treatment - subsurface irrigation Wet composting systems involve a series of filtration membranes or layers that separate out the solids from the liquids in common household wastewater. The water is then treated and made available for re-use (commonly for garden irrigation, laundry or toilet use) or fed into sub-surface absorption trenches. The solids are generally composted, commonly using worms. This compost can then use extracted and used in the garden. These systems also allow the composting of other household organic wastes (kitchen and green waste). http://www.aquaclarus.com/prod_sim_how.htm



System Name Biolytix Filtration Level of Treatme nt Biological secondary treatment - subsurface irrigation

Biolytix Filters separates primary organic solids from the wastewater and then treats the liquid biologically in an aerobic environment. The manufacturer claims to have better oxygen transfer than competing technologies and correspondingly lower energy costs. http://www.biolytix.com/filtration

System Name Envirosink® Level of Treatment Primary source separation - subsurface irrigation Envirosink is a funnel attachment to a sink that directs all greywater discharged to it directly to subsurface irrigation. It is an inexpensive device that requires the homeowner to select what water to discharge to the system. The user either swings the tap over the secondary sink or uses a bowl to capture the greywater and then pour it into the Envirosink, which drains into a transfer chamber, which typically pumps to the subsurface irrigation system or drains to the garden. http://www.envirosink.com/about.html

System Name Equaris Greywater Treatment System Level of Treatment Extended aeration secondary treatment - subsurface irrigation Greywater is drained to a series of small tanks for treatment, followed by filtration. The system includes a surge tank for flow control, followed by an extended aeration tank to produce aerobic conditions and finally a clarification tank to separate out biosolids grown in the system. Black water is not treated in this process, and is separated from the greywater stream. This reduces the amount of wastewater for treatment to about 40 gallons per person per day. The estimated treatment capacity of each Greywater Treatment System is 250 gallons per day. The resulting effluent is typically filtered and disinfected for reuse. http://www.alascanofmn.com/default.asp?Page=Wastewater

System Name Copa MBR Technology Level of Treatment Secondary biological treatment Copa MBR Technology is a secondary biological treatment process employs simple flat sheet membrane panels housed in stainless steel (304 or 316) units and aerated by a coarse bubble system below each unit. The incoming wastewater generally only requires screening and de-gritting prior to entering the membrane bioreactor tank. The membrane panels are manufactured with a pore size in the range of 0.1 to 0.4 microns, which in operation becomes covered by a dynamic layer of protein and cellular material, providing an effective pore size of less than 0.01 microns, which is in the ultra filtration range. http://www.copa.co.uk/products/mbr/default.asp



System Name Clearwater Treatment System Level of Treatment Separation, Biological (aeration), filtration, disinfection and RO. The ClearWater Technology's separates the toilet and kitchen organic wastes from the wastewater stream at the source. It then treats those wastes and the remaining wastewater (greywater) individually in two separate vessels via decomposition and extended aeration. The ClearWater Technology also reduces water consumption by 40 to 80% by incorporating toilets that consume less than one cup of water per flush. Greywater is treated aerobically in the ClearWater Extended Aeration Tank, and is then treated in the ClearWater Filtration Disinfection and Reverse Osmosis System. The three combined ClearWater Systems provide for the total treatment of toilet and organic kitchen wastes and wastewater, and produce water qualities for direct household reuse. There is no wastewater effluent discharge from the residence or facility. No septic tank or leachfield is used. http://www.epa.gov/region1/assistance/ceitts/wastewater/techs/clearwater.html

System Name The “Nature Loo” from Nature Clear Level of Treatment Filtration and subsurface irrigation Nature Clear incorporates a filtration tank, which is less than 1 cubic meter in size, consists of a pine bark coarse filter on top of a fine sand filter. The coarse filter removes large particles not caught in the upstream grease trap and lint from the washing machine. The sand filters out still finer materials, polishes the water and reduces the organic content of the water. The pine bark is separated from the sand by filter cloth. The filtered material and bark will compost over time and should be removed every six months and replaced with fresh bark, available from a local garden nursery. The filtered greywater drains to a 450 Litre pump well located in the ground alongside the filtration tank. The price of the Nature Clear Filtration Tank is AUD $750 (CDN $690) excluding sand and gravel. The price of the Nature Clear Pump Well is AUD $350 (CDN $320). http://www.nature-loo.com.au/greywater/natureclear/natureclear.html

System Name Wasser Recycling Solutions Level of Treatment Greywater separation, secondary treatment and disinfection The greywater is collected separately and drained into a settling tank. Water from the settling tank is then discharged to a rotating biological contactor (RBC) and the biosolids formed settle in a secondary settling tank. The secondary treated greywater is disinfected by means of UV-radiation and stored in a service water tank. The storage tank is automatically replenished with drinking water when the service water is in short supply. http://www.greywater.com/e_s2_konzept.html

Documents

CRD Greywater Reuse Study Final Report