Monitoring wastewater treatment (indicator 6.3.1)

6.3.1 Proportion of wastewater safely treated

Target 6.3 seeks to halve the proportion of untreated wastewater discharged into our water bodies - this page explains how to monitor progress towards this target, and which resources that are available for countries to do so

What and why?

The indicator focuses on how much of the wastewater generated by households and economic activities that is treated before it is returned into the environment. Data on the household component comes directly from the sanitation indicator 6.2.1, and as such includes both on-site sanitation and wastewater. The inclusion of on-site facilities is critical from a public health, environment and equity perspective, because approximately two thirds of the world’s population uses on-site facilities.

Wastewater from economic activities can include more toxic substances and is thus important to address; the methodology recommends an initial focus on hazardous industries.

By monitoring indicator 6.3.1, policy- and decision-makers learn where and what types of wastewater that are discharged without treatment and can target interventions accordingly, e.g. to focus on the safe management of on-site sanitation or the construction of sewage systems and centralized treatment plants, and which economic activities to follow-up on more closely.  

How to progressively Monitor?

For data sources and progressive monitoring for the household component of indicator 6.3.1, these are the same as for indicator 6.2.1.

To monitor wastewater from economic activities, a first step would be to make estimations based on registers of economic activities, as well as to focus on hazardous industries. As the monitoring matures, more and more accurate data could be collected by responsible institutions or wastewater utilities – for example through meters – who may also be increasingly able to provide information on treatment compliance.

A septic tank is being emptyied. Photo credit: Julian Doczi, Creative Commons Attribution

A septic tank is being emptyied. Photo credit: Julian Doczi, Creative Commons Attribution

On-site sanitation, such as latrines, is part of the wastewater challenge

On-site sanitation, such as latrines, is part of the wastewater challenge

The World Health Organization (WHO) and the United Nations Human Settlements Programme (UN-Habitat), on behalf of UN-Water, compiles country data at the global level and supports countries in their monitoring efforts.

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