Lake Powell: Passive Water Quality Samples

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Detailed Description

Passive water quality samplers (semipermeable membrane devices ) are used to monitor Polycyclic Aromatic Hydrocarbons in Lake Powell, AZ-UT.


Image Dimensions: 1920 x 1080

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Location Taken: US


Kurt Schonauer: My name is Kurt Schonauer, and my title with the USGS is hydrologist. The USGS has had a pretty long history with Lake Powell. Beginning in about 1921, prior to Lake Powell, we have a stream flow gage on the Colorado River at Lee's Ferry that began collecting data in 1921. And then when the dam was completed in 1963, which is Glen Canyon Dam that created Lake Powell, the USGS was collecting physical and chemical parameters for water quality.
Bob Hart:  Getting ready to collect a lake bed sample and we're going to use a device called a Ponar, or clam shell. Anyways it's lowered down through the water column and scoops up a nice sample of the lake bed material. And we'll pull it back up, then we'll take some samples out of the Ponar, put them in jars. We'll analyze for metals, hydrocarbons or PAHs, and also sediment size analysis. 
Kurt Schonauer: What we have here is our deployment canisters for our passive samplers, our SPMDs. And what we do is take this lid off, inside there's a post and the samplers come on small disks that they're wrapped on. And that disk has a hole in the middle which will just slide over this screw and then we'll deploy it into the water. 
Chris Smith: What are you measuring with these? 
Kurt Schonauer: With this we're measuring polycyclic aromatic hydrocarbons, and those cover a lot of things plasticizers, they cover hydrocarbons, various hydrocarbons we're going to be looking at. One of the main things, the reasons why we're doing this is to look at hydrocarbons that are the result of unburned fuel products from two stroke engines. 
The results from this study concluded that the highest concentrations of both polycyclic aromatic hydrocarbons and inorganic elements where found in the southern half of the lake near high traffic areas for boats. Although concentrations were found, none exceeded the Environmental Protection Agency's maximum contaminant level. So in general the quality of water on Lake Powell is very high, and the USGS looks forward to partnering with the National Park Service for future projects in monitoring these conditions. Thank you.