ISO 20760-1:2025

Overview

ISO 20760-1:2025 - Water reuse in urban areas: Guidelines for centralized water reuse system - Part 1: Design principle of a centralized water reuse system provides high-level, non‑prescriptive guidance for planning and designing centralized water reuse systems in urban settings. The standard covers the system lifecycle - from source water and treatment through storage, distribution, operation, monitoring and emergency response - and defines system components, possible system models, design principles and common assessment criteria (including example water‑quality indicators). It intentionally does not set numeric design parameters or regulatory threshold values.

Key topics and technical focus

• System planning and design principles
  • Estimation of reclaimed water demand and review of potential end uses
  • Consideration of site conditions and reliability
• System components and models
  • Source water, treatment trains, storage (open/closed/aquifer storage and recovery), distribution and user interfaces
  • Four example system models including single application, multiple applications, environmental storage and cascading uses
• Source water considerations
  • Types of source water (e.g., treated wastewater, untreated sewer flows, other sources)
  • Water‑quality and reliability assessment guidance
• Reclaimed water treatment
  • Design principles emphasizing safety, reliability, stability, economic viability and environmental protection
  • Possible treatment configurations and processes (high-level guidance)
• Storage and distribution
  • Storage sizing and turnover, open vs closed reservoirs, ASR considerations
  • Distribution design: pumping, flow/pressure, pipe materials, avoiding stagnation, color‑coding and service connections
• Monitoring and control
  • Monitoring locations (source, treatment, storage, distribution, end‑user) and operational control approaches
  • Guidance on water quality indicators without prescribing targets
• Emergency response
  • Specific aspects for contingency planning and incident response

Practical applications and users

ISO 20760-1:2025 is intended for professionals and organizations involved in urban water reuse projects, including:

• Water and wastewater utilities
• Municipal planners and infrastructure authorities
• Consulting engineers and system designers
• Treatment technology suppliers and integrators
• Operators, asset managers and public‑health policymakers

Typical applications include reclaimed water systems for irrigation, industrial cooling and processing, environmental flows, toilet flushing, and integrated cascading reuse schemes within cities - where centralized planning, consistent monitoring and operational reliability are required.

Related standards and implementation notes

• Use ISO 20760-1 alongside national regulations and local water‑quality standards (the document does not provide regulatory target values).
• Complementary guidance and standards on wastewater treatment, potable reuse, and water quality monitoring should be consulted during detailed design and permitting.

ISO 20760-1:2025 is a practical resource for establishing robust, safe and sustainable centralized water reuse systems in urban areas while aligning multidisciplinary stakeholders around common design principles.