Stream Turbidity Level (OI3979)

The metric is intended to capture the level of turbidity in streams or rivers on land managed by the organization as of the end of the reporting period.

Organizations should collect these data immediately downstream of controlled land, as reported by Land Directly Controlled: Total (OI5408), Land Indirectly Controlled: Total (PI3789), and related submetrics. Turbidity measurements should be taken seasonally, because streamflow varies seasonally.

Organizations should consult national, sub-national, or tribal standards to determine whether measured turbidity levels are within environmentally sustainable levels.

Guidance on turbidity measurements can be found from the US Environmental Protection Agency (https://www.epa.gov/sites/production/files/2015-09/documents/turbidity.pdf) and USGS (https://www.usgs.gov/special-topic/water-science-school/science/turbidity-and-water?qt-science_center_objects=0#qt-science_center_objects). For guidance on turbidity measurement conversions, see USGS guidance (https://or.water.usgs.gov/grapher/fnu.html).