Wastewater Treated (OI9412)

This metric is intended to capture how much wastewater derived from an organization's productive or operational processes is treated.

Wastewater, or water that carries wastes, is usually a mixture of water and dissolved or suspended solids. Treatment aims to improve the quality of the wastewater before the remaining water is discharged back to the environment by reducing suspended solids, biodegradable organics, pathogenic bacteria, and nutrients. Wastewater treatment typically takes place over three levels: primary (mechanical), secondary (biological), and tertiary. Organizations may further specify the wastewater's level of treatment by disaggregating this metric by Water Treatment Level (OI9278).

In some contexts, this metric can serve as an indicator of whether the outcome being sought by an investor or organization is occurring (the WHAT dimension of impact). For more on the alignment of IRIS metrics to the five dimensions of impact, see IRIS+ and the Five Dimensions of Impact (https://iris.thegiin.org/document/iris-and-the-five-dimensions/). No single metric is sufficient to understand an impact; rather, metrics are selected as a set across all dimensions of impact. When possible, the selection of metrics to measure and describe the five dimensions should be based on best practice and evidence.