ISO/TC 282 - Water reuse

This document provides guidelines to evaluate the benefits of reclaimed water for applications requiring different levels of water quality and for beneficial use in urban areas. This document is applicable, among others, by practitioners and authorities to assist water reuse planning, design, operation and management. This document provides evaluation indicators, procedures and examples of reclaimed water use benefits. Design parameters and regulatory values of different reclaimed water uses as well as risk or safety evaluation of reclaimed water use are out of scope of this document.

This document sets out the general principles for, and provides guidance on, the quantitative characterization of energy recovery from wastewater and sludge treatment, and how to account for this in the total energy consumption calculation. The scope of this document includes: — a definition of the main energy recovery processes applicable to industrial wastewater treatment and sludge treatment for reuse, such as anaerobic digestion yielding biogas; — an introduction to the possible forms of energy generated by energy recovery processes and systems, such as electricity, steam or heat, and how to account for intentional wasting or commercial utilization of biogas; — guidance on the value to be taken into account as quantification of the energy generated, including the power actually generated on average; — a limit level for contaminated components in biogas allowed before any utilization; — principles to integrate the energy recovery results with the energy consumption in accordance with ISO 21939-1. Energy production which is not recovered from wastewater or sludge treatment processes is not within the scope of this document and is not included in the calculations and results expressed in it.

This document provides guidelines for the evaluation of the fertilizer value of treated wastewater (TWW) at different treatment levels, for an effective fertilization of crops irrigated with TWW. This document covers: — evaluation of the nutrient quantities provided by TWW and the synchronization between crop needs and the nutrients applied with TWW; — availability of nutrients to crops irrigated with TWW; — monitoring nutrients in water, soil and crops irrigated with TWW; — matching between TWW quality and fertilizer properties. Risk assessment and risk management for the safe use of TWW in irrigation projects are addressed in ISO 20426[1] and ISO 16075-2[2].

This document defines terms and definitions commonly used in water reuse standards. It is applicable to all types and sizes of water reuse facilities and systems and to all types of stakeholders involved in water reuse.

This document specifies guidelines for wastewater treatment and reuse in thermal power plants, including the types and characteristics of wastewater and the technologies of wastewater treatment and reuse. In this document, thermal power plant drainage systems are divided into fuel supply, chemical water treatment, boiler and auxiliary, recirculating cooling, flue gas processing, gasification scrubber and ash handling. Wastewater from these systems is classified in accordance with its system sources. In addition, technical guidelines for wastewater treatment and reuse are provided according to the water requirements of systems in the thermal power plant. This document is formulated to provide feasible technical guidance for the treatment and reuse of wastewater in thermal power plants. It is applicable to coal-fired, oil-fired, gas-fired (including gas turbine), biomass-fired, waste incineration and integrated gasification combined cycle (IGCC) thermal power plants.

This document specifies the general principles and provides guidance on the quantitative characterization of the life cycle cost of a complete wastewater management system, including collection, treatment and, optionally, reuse. It enables the consideration of different degrees of distribution, including non-sewered systems for one or more dwellings and associated trucking operations. The methodology provided in this document is applicable to urban or rural areas wherein several decentralized wastewater treatment and reuse systems can provide a lower cost solution than a single centralized plant. Similarly, the same methodology can be applied for industrial reuse systems, where several separate plants on a large industrial site can be considered instead of one treatment system. The scope of this document includes the following: a) Guidance on the determination of the degrees of distribution of decentralized wastewater treatment and reuse systems. b) A definition of the elements and components included in the life cycle cost of the different degrees of distribution in wastewater management systems, including construction, operation and maintenance. c) Guidance on the required steps for calculating life cycle cost indicators, including considerations of term and interest, operation and maintenance, replacement parts, equipment life expectancy, the value of water for reuse and other income from by-products. d) A definition of the metrics for reporting results, including the cost per unit, scope, term and interest. The following secondary costs and other considerations are not within the scope of this document: — cost of eventual disposal of the system; — guidance on wastewater treatment process selection and design; — health and sustainability considerations (although health and sustainability are primary considerations in design and decisions); — social impact factors and/or environmental risks and impacts.

This document provides a benchmark for evaluation of the design, operation and performance of water for injection (WFI) generation systems based on membranes. This document is applicable to the design of new systems. This document covers the following topics: — principles of membrane-based WFI generation systems; — process design, construction, operation and maintenance of membrane-based WFI generation systems; — controlling membrane-based WFI generation system parameters. This document does not cover the following topics: — validation; — distillation.

This document provides guidelines for the treatment and reuse of MSW leachate. It is applicable to personnel involved in the design, management, operation and supervision of the treatment and reuse of MSW leachate and environmental authorities engaged in regulation.

This document provides parameters and methods for water quality stability evaluation of reclaimed water. This document can be used in various stages of water reclamation projects including storage, transportation, application and post-assessment. This document considers the needs and utilization of reclaimed water and is applicable to the evaluation and management of water quality stability of reclaimed water from municipal wastewater sources, including chemical stability and biological stability.

This document provides life-cycle cost (LCC) methodology for treatment systems for water reuse for initial planning as well as later performance evaluation. LCC analysis provides valid information to determine whether the objectives have actually been accomplished and how operations are improved and optimized. Environmental impact is also taken into account in the LCC evaluation.

This document provides guidelines for performance evaluation methods of water reclamation systems using membrane technologies. This document provides guidance in ensuring treated wastewater quality levels at the point of exit from the membrane filtration processes. It also provides potential methods for evaluating the environmental and economic performance of membrane filtration processes in water reuse. This document helps plant designers, operators and end users to effectively design and operate the membrane-based water reclamation systems.

This document provides guidelines on methods for evaluating the performance of ion exchange and electrodialysis for water reuse including ion exchange resin and ion exchange membrane.

This document provides a performance evaluation method of treatment technology using advanced oxidation processes (AOPs) for water reuse treatment. It introduces a system of evaluating water quality to validate AOP performance through typical parameters such as the concentration of hydroxyl radicals.

This document provides a guideline for the application of various available methods of treated wastewater (TWW) disinfection for an effective inactivation or removal of pathogens from TWW, which is intended for irrigation purposes. This document deals with: — chemical and physical technologies, principles of operation, and establishment of effective doses to be applied, possible interferences, and technical guidance for design and monitoring; — comparison of the advantages and disadvantages of various disinfection methods suitable for TWW; — potential environmental effects of the disinfection methodologies and ways to minimize those impacts; — disinfection at different locations in the TWW use system, including in the wastewater treatment plant, within the distribution system and at the point of use.

This document provides recommendations regarding: — monitoring the quality of treated wastewater (TWW) for irrigation; — monitoring irrigated plants; — monitoring the soil with regard to salinity; — monitoring natural water sources in neighbouring environments; — monitoring the quality of water in storage reservoirs. It puts emphasis on sampling methods and their frequency. Regarding the methods of analysis, this document refers to standard methods or, where not available, to other bibliographical references. NOTE In cases where a monitoring plan already exists, these recommendations can be integrated into this plan. This is notably the case when a broader approach of risk management is implemented, such as the water safety plans (serving as a model for sanitation safety plans) developed by WHO[16].

This document covers the system's components needed for the use of treated wastewater (TWW) for irrigation. Emphasis is placed on irrigation methods, mainly drip irrigation, as this method represents an efficient method of irrigation and water saving, while reducing the pollution of the crops. Despite the fact that water quality and filtration of treated wastewater (herein TWW) using drip irrigation are critical, open irrigation systems are more popular and are frequently used for irrigation with TWW and therefore are covered in this document. This document covers issues related to the main components of a TWW irrigation project, including the following: — pumping stations; — storage reservoirs; — treatment facilities (for irrigation purposes); — filtration and disinfection; — distribution pipeline networks; — water application devices: irrigation system components and treatment. This document is not intended to be used for certification purposes.

This document provides guidelines for performance evaluation methods of UV disinfection for full scale water reuse systems. It deals with the methods of measurement of typical parameters which indicate performance of UV disinfection systems.

This document specifies the principles and framework for comprehensive evaluation of industrial wastewater treatment reuse processes, including: a) establishing goals and scope; b) illustrating the evaluation procedure; and c) determination of evaluation indicators (technology indicator/sub-indicators, environment indicator/sub-indicators, resource indicator/sub-indicators, economy indicator/sub-indicators). This document describes how to comprehensively evaluate industrial wastewater treatment reuse processes using the proposed calculation approaches and recommended indicators. It does not specify methodologies for single evaluation indicators. The document is intended to provide assistance to a broad range of industrial wastewater treatment and reuse project stakeholders including professionals (planning, management, designers, and operators), administrative agencies (monitoring, assessment, regulation and administration) and local authorities. This document is applicable to a) evaluating comparing and selecting industrial wastewater treatment reuse processes, b) implementing continuous improvements, c) upgrading processes and improving performance for existing treatment and reuse facilities. The intended application of the comprehensive evaluation result is considered within the goal and scope definition.

This document provides guidelines for the planning and design of a reverse osmosis (RO) treatment system of municipal wastewater. This document is applicable to practitioners and authorities who intend to implement principles and decisions on RO treatment of municipal wastewater in a safe, reliable and sustainable manner. This document addresses RO treatment systems of municipal wastewater in their entirety and is applicable to any RO treatment system component. This document provides: — standard terms and definitions; — a description of the system components of an RO treatment system of municipal wastewater; — design principles of an RO treatment system of municipal wastewater; — statements on the feed water quality and technical requirements of an RO treatment system; — guidance for operation and maintenance of an RO treatment system; — specific aspects for consideration and emergency response. Design parameters and regulatory values of an RO treatment system of municipal wastewater are out of the scope of this document.

This document covers the following issues: — guideline for the design of treated wastewater (TWW) irrigation projects intended to prevent public health risks within the population that has been in direct or indirect contact with the TWW or with any product that has come in contact with the TWW; — specifications of the following: i) TWW quality for irrigation purposes; ii) types of crops for TWW irrigated; iii) TWW and crops qualities integration; iv) use of barriers to reduce risks arising from TWW irrigation; v) correlation between the quality of the TWW, irrigated crops, and the types of barriers that can be used; vi) distance between TWW irrigated areas and residential areas. None of the documents of ISO 16075 are intended to be used for certification purposes.

This document contains guidelines for the development and the execution of projects intending to use treated wastewater (TWW) for irrigation and considers the parameters of climate and soil. The purpose of this document is to provide guidance on all elements of a project using TWW for unrestricted and restricted irrigation, including design, materials, construction, and performance, when used for the following: — irrigation of agricultural crops; — irrigation of public and private gardens and landscape areas, including parks, sport fields, golf courses, cemeteries, etc. These guidelines are intended to provide assistance for the benefit of users of TWW for irrigation. The guidelines relate to the widespread and common ranges of water quality rather than exceptional or unique ones and are intended for the use of professionals, such as irrigation companies (designers and operators), agricultural extension officers or advisors, water companies (designers and operators), local authorities and water utilities. The use of these guidelines by users might require additional specifications. None of the parts of this document are intended to be used for certification purposes. These guidelines suggest the parameters of TWW quality. These parameters include the following: — agronomic parameters: nutrients (nitrogen, phosphorus and potassium), salinity factors (total salt content, chloride, boron, and sodium concentration) and heavy metals' concentration; — pathogen presence. Each of these parameters can have possible impacts on the crops, soil, and public health. The guidelines discuss the possibility of preventing the contaminants' addition during wastewater production and the ability to remove them during the course of treatment. Contaminants of emerging concern (such as pharmaceuticals and personal care product residuals) are outside the scope of this document since up to day, there is no evidence of adverse effects on human health or environment via irrigation with TWW or via the consumption of crops irrigated with TWW. The project should be designed in accordance with the sanitary quality of the TWW in order to avoid disease transmission by the pathogens in the water. The use of these guidelines is encouraged to ensure consistency within any organization engaged in the use of treated wastewater. These guidelines provide the basis for a healthy, hydrological, environmental and agronomic conscious design, operation, monitoring, and maintenance of an irrigation system using treated wastewater.

This document provides guidelines for the planning, design principles and considerations of a decentralized/onsite water reuse system and water reuse applications in urban areas. This document is applicable to practitioners and authorities who intend to implement principles and decisions on decentralized water reuse in a safe, reliable and sustainable manner. This document addresses decentralized/onsite water reuse systems in their entirety and is applicable to any water reclamation system component (e.g. source water collection, treatment, storage, distribution, operation and maintenance and monitoring). This document provides: — standard terms and definitions; — description of system components and possible models of a decentralized/onsite water reuse system; — design principles of a decentralized/onsite water reuse system; — common assessment criteria and related examples of water quality indicators, all without setting any target values or thresholds; — specific aspects for consideration and emergency response. Design parameters and regulatory values of a decentralized/onsite water reuse system are out of the scope of this document.

This document provides guidance on, the evaluation and comparison of wastewater softening and desalination processes for industrial wastewater reclamation and reuse with specific consideration for the following six: 1) chemical precipitation; 2) ion exchange; 3) nanofiltration (NF); 4) reverse osmosis (RO); 5) electrodialysis (ED) and 6) electrodeionization (EDI). This document provides guidance on the characterisation of both influent and effluent quality (e.g. hardness, alkalinity, etc.) and the effects of these processes on those constituents. The purpose of softening and desalination is only for the reuse usages that have requirements for hardness and salinity, such as cooling circulating water, boiler water, production process water, and cleaning water. This document includes the following sub-processes of wastewater softening and desalination processes: a) wastewater softening processes based on chemical precipitation, ion exchange and NF, which aim to remove hardness ions, such as Mg2+ and Ca2+; b) desalination processes based on ion exchange, RO, ED, EDI and NF, which aim to remove the most of total dissolved solids (TDS). This document is applicable to: a) industrial saline wastewater, which has been pre-treated to remove most of the organic matters if necessary; b) the selection or design of wastewater softening and desalination processes for reuse of wastewater from industries.

This document specifies performance evaluation methods of treatment technology using ozone for water reuse systems. It deals with how to measure typical parameters which indicate performance of ozone treatment technology.

This document provides the fundamental principles and guidelines for industrial wastewater treatment technology pilot studies. It does not address laboratory research and development, study or testing of a given technology. It does not cover reuse applications or operations, such as irrigation. This document applies to a wide range of industrial water treatment systems for the purposes of reuse.

This document provides guidelines for cost analysis of the use of reclaimed water in industrial cooling systems. This document is intended for new-built industrial cooling systems using reclaimed water as make-up water, in which the reclaimed water originates from industrial wastewater and is generated through wastewater treatment systems for reuse. The source of industrial wastewater is from all the production plants inside the enterprise. In this document, the levelized cost of cooling water (LCOCW) is used to compare and determine which industrial cooling system is more expensive per-kilowatt-hour heat removed. Use of reclaimed water will have a direct impact on the operating cost of cooling systems and the environment. External benefits, including positive externalities and negative externalities, are provided in Annex A, which considers environmental, social and financial elements. This document is intended for all types of stakeholders involved in reclaimed water use in new-built industrial cooling systems. This document aims to ensure consistency within any organization engaged in reclaimed water reuse. This document provides a broad framework within which costs for new-built industrial cooling systems using reclaimed water can be assessed. The currency used is local currency (LCY).

This document defines terms related to industrial cooling water systems and specifies technical guidelines for the use of reclaimed water for make-up water purposes water in industrial cooling systems. It provides a basic framework for consideration in the design and operation of industrial cooling systems using reclaimed water. The aim of the document is to promote and to help the implementation of the use of reclaimed water in industrial cooling systems. It provides: — Terms and definitions; — Technical guidelines for the use of reclaimed water in industrial cooling systems. This document is applicable to cooling systems that are considered to work as auxiliary systems for the normal operation of an industrial process. However, the operation of a cooling system in relation to process safety is not covered in this document. In addition, some environmental concerns also need to be taken into consideration, for example the drift control or the use of some persistent biocides. This document can be used to encourage consistency within any organization engaged in the use of reclaimed water.

This document specifies the principles, categories, and codes for the classification of industrial wastewater and is applicable to all types and sources of industrial wastewater. It provides a broad framework classifying industrial wastewater into different categories based on industry type and the associated water quality constituents, namely physical, chemical and biological characteristics with a specific code assigned based on both industry type and waste-stream classification.

This document provides guidelines for evaluating the performance of treatment systems on the basis of greenhouse gas (GHG) emissions. In order to estimate greenhouse gas emissions from a treatment system, this document covers the estimate, types of GHG emission and sources, emission factor for each GHG, and global warming potential. The weight of greenhouse gases to be used in an evaluation is equivalent to emissions during operation of a treatment system. This document also defines a method for calculating carbon dioxide equivalent (CO2eq) emission intensity, in which GHG emissions are divided by the volume of reclaimed water. It also includes a method for evaluating the performance of a treatment system using CO2eq emission intensity.

This document sets out the general principles for, and provides guidance on, the quantitative characterization of the energy consumed by industrial biological wastewater treatment systems. It does not aim to characterize the treatment pollutants removal performance or process reliability or any other consideration in the selection of a wastewater treatment system. This document includes the following sub-systems of biological treatment system: — Biological reactors, which might be suspended growth or fixed film processes or a combination thereof, and can include anaerobic, anoxic and/or aerobic tanks and/or zones. — Solid-liquid separation processes such as sedimentation, flotation, or membrane filtration, used for clarification of the water before discharge to downstream processes, which can also involve the return of a the separated solids as sludge back to the biological reactor. — Any pumps, blowers and mixers for water circulation, mixing and air supply in and between the sub-systems listed herein. — Heating or cooling of the water for treatment. This document does not include the following subsystems of the biological treatment system: — Wastewater feed pumps. — Pre-treatment systems, which for the purposes of this document also include preliminary and primary treatment processes, such as but not limited to, screening, sedimentation, dissolved air flotation, chemical oxidation, oil separation. — Post-treatment processes, such as but not limited to, disinfection, desalination, ion exchange, sludge treatment and handling systems. — Site lighting or any energy consumption involved in office operation. — Energy recovery from processes such as anaerobic reactors producing biogas. Filtration processes, which are sometimes part of the biological treatment process and at other times part of the post treatment, are referred to separately within this document.

This document provides guidelines for water quality grade classification to help users determine the suitability and quality of the reclaimed water for safe non-potable reuse applications, based on the level of exposure. The intention is to enable the water quality grade to be identified at the point of use.

This document gives guidelines on performance evaluation of treatment technologies for water reuse systems. It provides typical parameters of water quality and treatment efficiency that are associated with the performances of treatment technologies. It also includes a comparison of measured and target values, and provides treatment technology functional requirements and non-functional requirements.

This document provides guidelines to planners and practitioners on how to adjust irrigation equipment so as to allow direct utilization of treated wastewater (TWW) for irrigation. It deals with the adjustment of all components of irrigation systems to TWW quality in respect to physical, chemical and biological parameters. This document provides guidelines on how to protect irrigation equipment so as to guarantee water systems functionality at high levels of efficiency. This document includes recommendations for a) pumping stations, b) filtration, c) water network systems, d) irrigation equipment: emitters (drippers, sprinklers, mini sprinklers, micro sprinklers, sprayers and irrigation machine (sprinklers and sprayers), e) physical treatment of irrigation equipment, and f) chemical treatment of irrigation equipment. This document defines TWW parameters at the irrigation system inlet after a wastewater treatment plant, in order to allow optimal and continual functioning of the irrigation systems and to allow uniformity of emitters' discharge.

This document provides water reuse safety evaluation and public acceptance parameters and methods for users who design, manage, and/or oversee the non-potable water reuse schemes or activities in urban areas from the viewpoint of water quality. The document can be used in various stages of non-potable water reuse projects such as design, operation, and post assessment. The document is applicable to non-potable water reuse in urban areas with reclaimed water from municipal wastewater sources. The wastewater sources can also include a limited contribution of industrial wastewater input. While some communities are turning to potable reuse to meet water supply needs, discussion of safety evaluation of potable reuse is outside the scope of this document.

This document aims to serve as technical guidelines for the assessment and management of the health risks associated with pathogens contained in reclaimed water, which are expected to be caused by the use of reclaimed water, and/or by the production, storage, and transportation of reclaimed water. This document is applicable to the use of reclaimed water made from any source water (i.e. raw sanitary sewage; treated municipal wastewater; industrial wastewater; stormwater potentially influenced by sewage) and for non-potable water reuse. NOTE The approach described in this document can be applied to chemical contaminant, if applicable.

ISO 20760-1:2018 provides guidelines for the planning and design of centralized water reuse systems and water reuse applications in urban areas. ISO 20760-1:2018 is applicable to practitioners and authorities who intend to implement principles and decisions on centralized water reuse in a safe, reliable and sustainable manner. ISO 20760-1:2018 addresses centralized water reuse systems in their entirety and is applicable to any water reclamation system component (e.g. source water, treatment, storage, distribution, operation and maintenance and monitoring). ISO 20760-1:2018 provides: - standard terms and definitions; - system components and possible models of a centralized water reuse system; - design principles of a centralized water reuse system; - common assessment criteria and related examples of water quality indicators, all without setting any target values or thresholds; - specific aspects for consideration and emergency response. Design parameters and regulatory values of a centralized water reuse system are out of the scope of this document.

ISO 20760-2:2017 provides guidelines for the management of centralized water reuse systems and water reuse applications in urban areas. ISO 20760-2:2017 is applicable to practitioners and authorities who intend to implement management concepts, principles and supports on centralized water reuse in a safe, reliable and sustainable manner. ISO 20760-2:2017 addresses centralized water reuse systems in their entirety and is applicable to any water reclamation system component (e.g. source water, treatment, storage, distribution, operation and maintenance and monitoring). ISO 20760-2:2017 provides: - standard terms and definitions; - principles and methodology of reclaimed water management; - management issues in each system component of a centralized water reuse system; - specific aspects for consideration and emergency response. Monitoring parameters and regulatory values of a centralized water reuse system are out of the scope of this document.

This document provides guidance for deep purification of secondary effluent for non-potable reuse by using biological filtration systems in urban areas. It specifies general requirements, system selection, biological filtration system components, technical requirements of each component, water reuse applications and system design considerations. This document is applicable to: a) engineers that intend to implement biological filtration systems for deep purification of secondary effluent for reuse purposes in terms of design and implement, under safe and stable circumstances; b) enterprises who assist spreading high-efficiency water reuse technology among different countries and accelerate the technological progress in the field of secondary effluent reuse.

This document specifies design, materials selection, construction and operation of Purified Water (PW) and Water for Injection (WFI) pretreatment and membrane-based production systems. As many different types of feed water are possible, different components and configurations are presented. A decision matrix is provided to give guidance for the different types of feed water. This document excludes — selection of the appropriate compendial water definition per system: e.g. PW, WFI or other; — thermal process for generation of PW/WFI; — loops, storage and distribution; — pure steam generation and distribution; — laboratory water systems and — validation.

This document defines terms and definitions commonly used in water reuse standards.

ISO 16075-4:2016 provides recommendations regarding: · monitoring the quality of treated wastewater (TWW) for irrigation; · monitoring irrigated plants; · monitoring the soil with regard to salinity; · monitoring natural water sources in neighbouring environments; · monitoring the quality of water in storage reservoirs. It puts emphasis on sampling methods and their frequency. Regarding the methods of analysis, ISO 16075-4:2016 refers to standard methods or, where not available, to other bibliographical references.

ISO 16075-3:2015 covers the system's components needed for the use of TWW for irrigation which relate to various pressure and open irrigation systems specifically drip irrigation as this method represents an efficient method of water delivery and water saving. Despite the fact that water quality and filtration of treated wastewater (herein TWW) using drip irrigation are critical, open irrigation systems are more popular and are frequently used for irrigation with TWW and therefore are covered in this part of ISO 16075. ISO 16075-3:2015 will cover the issues related to the main components of a TWW irrigation project, including the following: pumping station; storage reservoirs; treatment facilities (for irrigation purposes): filtration and disinfection; distribution pipeline network; water application devices: irrigation system components and treatment.

ISO 16075-2:2015 covers the following issues: criteria for the design of treated wastewater (herinafter: TWW) irrigation projects intended to prevent public health risks within the population that has been in direct or indirect contact with the TWW or with any product that has come in contact with the TWW; specifications of the following: the quality of the TWW that can be used for irrigation; the types of crops that can be irrigated with TWW; the combination of the qualities of the irrigated TWW and the types of crops that can be irrigated; the strategy of using barriers that can reduce the risks that arise from TWW irrigation; the correlation between the quality of the TWW, the irrigated crops, and the types of barriers that can be used; the distance required between the TWW irrigation areas and residential areas.

ISO 16075-1:2015 contains guidelines for the development and the execution of projects intending to use treated wastewater (TWW) for irrigation and considers the parameters of climate and soil. The purpose of these guidelines is to provide specifications for all elements of a project using TWW for irrigation, including design, materials, construction, and performance, when used for the following: unrestricted irrigation of agricultural crops; restricted irrigation of agricultural crops; irrigation of public and private gardens and landscape areas, including parks, sport fields, golf courses, cemeteries, etc; irrigation of private individual gardens. These guidelines are intended to provide assistance for the benefit of users of TWW for irrigation. The guidelines relate to the widespread and common ranges of water quality rather than exceptional or unique ones and are intended for the use by professionals, such as irrigation companies (designers and operators), agricultural extension officers or advisors, water companies (designers and operators), and local authorities. The use of these guidelines by farmers might require additional specifications.