Public Lab Research note

Documenting Runoff with Photography

by mlamadrid , gretchengehrke | June 22, 2016 01:00 22 Jun 01:00 | #13224 | #13224

Article by Gretchen Gehrke for Community Science Forum: Sand-Frac Issue.

Photo documentation is among the most actionable types of community-collected data. County and state environmental permit enforcement agents in Wisconsin and other states have said that photographs of river fouling are useful evidence for documenting permit violations. The most actionable photographs for permit enforcement demonstrate the source of the runoff, duration of the event, and the visible extent of the fouling.

Sand mines and processing plants must comply with Wisconsin Pollutant Discharge Elimination System (WPDES) Permit WI-0046515, and therefore are not authorized to directly discharge wastewater, including that from settling ponds or dust suppression spraying, into surface waters. Discharges from a mine must have less than 40 mg/L total suspended solids. Total suspended solids (TSS) are any solids in waterbody that can be caught on a filter. If there is a visible plume of muddy water in a stream, it could easily have 400 mg/L TSS, 10-times higher than allowed. As a proxy for TSS, turbidity can be measured. Turbidity is the cloudiness of water, measured by the amount of light scattered by suspended particles. The more suspended particles there are, the more light will be scattered and the water will appear cloudy, or ‘turbid.’

Time lapse photography of streams, where a weatherized camera is placed near a stream and takes photos at regular intervals, could automatically capture actionable evidence of turbid runoff events during the day. A time series showing the river before, during, and after the event can assist enforcement agents in estimating the total volume of the discharge. Coupled with an in-stream turbidity meter, the timing of runoff events could be easily identified and selected from the time lapse camera’s image series. A turbidity meter can also record evidence of runoff events occurring at night. Public Lab’s community is developing a low-cost turbidity meter for this purpose. Time lapse functionality is built in to a variety of “trail cams” and other emerging small cameras, such as the Mobius Point and Shoot.

Look for more information and an example demonstrating the impact of community photo documentation in the next issue of the Community Science Forum! Read more about the process online at:

_Photo credit: Bill Hughes _


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