Food Safety

Four Waters, One Molecule: Keeping Potable, Wastewater, Irrigation and Sludge Apart

By AGS Compliance Team May 21, 2026 2 min read
Four Waters, One Molecule: Keeping Potable, Wastewater, Irrigation and Sludge Apart

Water is the same molecule in four states of trust: it is drunk; it is used and becomes sewage; it is treated and becomes irrigation water fit for landscape but never for lips. Every rule in water management is a barrier between those states — and every cross-connection, unmarked pipe or skipped disinfection is a breach waiting to reach a tap.

Why water systems are judged by their weakest joint

Utilities are inspected on point-of-use quality, chlorine residuals, tanker discipline and monthly reports — but incidents are born in the details: a repaired main returned to service undisinfected, a storage tank never dosed, an irrigation line without its markings. Systems survive on procedures, not luck.

What the AGS guideline covers

The AGS Hygiene & Sanitation Guidelines for Water are the international normalization of source regulation PHC-C-15, aligned with the WHO Guidelines for Drinking-water Quality — including the water safety plan framework — and the WHO guidelines for the safe use of wastewater. Its 34 sections and preserved quality tables cover:

  • Potable water quality at the point of use — standards, chlorine residual and turbidity
  • Step-by-step disinfection of new and repaired mains and storage tanks
  • Transportation of potable water and chlorination on filling
  • Wastewater collection, prohibited discharges and effluent monitoring
  • Irrigation water criteria, application restrictions, signage and tanker marking
  • Sludge reuse conditions, sampling, records and emergency response

The annexes carry the tables the whole code turns on: the source-preserved irrigation and potable water quality standards with their notes, a comparison with contemporary WHO guideline values, complete disinfection procedure references for mains and storage tanks, a six-part system inspection checklist and a jurisdictional adaptation register.

Who benefits

Utility and network operators get executable disinfection procedures; irrigation and reuse schemes get their quality tables and marking rules; inspectors get one code across all four waters.

Get the Guideline

Keep the four waters where they belong. Download the AGS Water guideline — instant download, fully editable Microsoft Word document, with the complete disinfection procedures and quality tables inside. Like every document in the AGS Technical Guidelines Library, it arrives as a clean, professionally structured file you can rebrand, adapt and issue as your establishment's own controlled document — no waiting, no shipping, no formatting work.

Product: Water — available as an instant-download, fully editable package from AGS (SKU AGS-05-013).

The toolkit for this guide: Hygiene & Sanitation Guidelines - Water. Instant download, fully editable, yours to keep.

AGS Compliance Team

Our toolkits and guides are written by practising auditors who assess management systems against ISO, BRCGS, HACCP and Halal schemes. Every document reflects what assessors actually look for.