ISO 24521

What is ISO 24521?


ISO 24521, Activities relating to drinking water and wastewater services—Guidelines for the management of basic on-site domestic wastewater services, is an international management standard, written from an operator's perspective. It provides guidance for the management of basic on-site domestic wastewater services, using appropriate technologies in their entirety at any level of development.

The standard includes guidance for maintenance techniques, training of personnel and risk considerations; user perspectives; guidance on the design and construction of basic on-site domestic wastewater systems; and guidance on planning, operation and maintenance, and health and safety issues. ISO 24521 is applicable to both publicly and privately operated basic on-site domestic wastewater (black and grey water) services for single and multiple dwellings.

It was published September 2016 and available for national adoption and use.

A Two-Step Solution


ISO 24521 and ISO 30500 work hand in hand to improve health, reduce the environmental impact of wastewater treatment, and offer affordable options for users and communities to help change the lives of 2.4 billion people. Whereas ISO 24521 optimizes existing wastewater services, the publication of ISO 30500 encourages the development of new technologies and solutions as current technologies are failing to address underlying challenges behind the lack of sanitation, including poverty, infrastructure and resources. We encourage national standards bodies to consider reviewing & nationally adopting ISO 30500 and ISO 24521 simultaneously.

Technical information on ISO 30500.
Technical information on ISO 30500.

Luvu Faecal Sludge Management Site, Kathmandu, Nepal