Hydrogeology Research: Thirsty Work

The past few weeks have been my first as a full-time researcher, and I have learned a lot about my project and about myself. The unstructured nature of research is so radically different than classes that at first I was frustrated by the slow pace at which I seemed to be making progress. I’m learning that the truth is, if you are doing sound research and digging into making sense of your data, it takes a while. I unrealistically believed I could knock down a major research question a week for the summer. The reality is that some weeks, all you do is raise more questions.

For this post, I’m going to focus on some of the regular data-collection tasks I do out at Jamestown Island and how I get it back to the lab. Remember: my overall goal is to figure out how saline the water consumed by the early Jamestown Colonists was. In the process of doing that I need to collect data that will tell me where the water is coming from, what the aquifer is like, and how tidal and seasonal changes in the James River affect the water quality beneath the fort.

To orient yourself, here is a map of the site. Each Well is denoted with a white dot. From this aerial photo, you can clearly see the outline of the fort, which is partially cut off by the James River.

Jtown Map

 Getting There and Equipment

First off, I am always accompanied into the field Emily Barnett, a fellow Geology senior who is researching the use of some geochemical tracers to source the water in the wells. She’s a great companion and we accomplish more together than we ever could alone. Since I’m taking pictures, she features prominently in what follows.

We drive to Jamestown in the Geo department van with what instruments we need for the day:

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The trusty steed

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Extremely high tech and complicated instrumentation.

Instrumentation

Generally we take water level gauges, a probe that tells us water temperature, how many dissolved salts are in the water,  and how much dissolved oxygen is in the water. We also take waders to go into the swamp, a pH meter, plastic bailers to remove water from the wells, and Emily has a water filter and acidified and un-acidified sample bottles so she can take water samples back to the lab.

Here are what the wells (technically piezometers) look like:

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This is actually 2 wells, which are made of PVC pipes, that are at different depths. Field notebook to scale. The water level gauge is in front of the well. John Smith is in the background.

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A well with a datalogger in it. The datalogger records the elevation of the water table and how many dissolved salts are in the water every 15 minutes by using a pressure transducer and a conductivity probe.

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Conductivity/ Dissolved Oxygen/ Temperature Probe

Our typical sampling day means that we go to each well, record the depth to water, conductivity, dissolved Oxygen, pH, and sample water. The sampling takes a while because we bail out the wells to make sure we’re getting freshwater. Sampling typically takes all morning.

There are staff gauges (essentially big measuring sticks) that are in the swamp that give us an indication of the level of the swamp. Checking these requires some mucking about in the swamp. This summer we also installed a sonic reader that records the height of the swamp every 5 minutes by sending a sound wave and recording the bounce off of the water surface. Here are some swamp photos:

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The sonic reader installed beneath the bridge in the swamp.

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Me in the Swamp.

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Emily in the swamp during a slug test. Note the well in the bottom right.

Collecting Data

Everything is recorded in my field notebook, then taken back to the lab and entered in a spreadsheet. Whenever researching a natural phenomena, the data can get a little messy. It can get especially messy when your field notebook accidentally falls in the swamp. Thank goodness for water resistant paper!

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I gotta work on being neater in my field notebook.

On occasion, we’re joined by our great faculty advisers,  Jim Kaste (not pictured) and Greg Hancock (below).

 

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He has the patience to handle my mistake-riddled and reiterative learning process.

      So that’s all for now. I’ll post again with more substance about what I’m doing and why. But I think it helps to have visual clues on what the heck I’m talking about.

Cheers,

Phillip