The source of elevated constituents is speculative, but... - Part 3

Brian Fontenot, the lead author on the recently "just accepted" manuscript titled "An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale Formation" is quoted on the UT Arlington webpage describing the study, stating:

“This study alone can’t conclusively identify the exact causes of elevated levels of contaminants in areas near natural gas drilling, but it does provide a powerful argument for continued research,”

As a recent graduate from a Master's program in Public Health, I had to read a bunch, and I do mean a bunch, of peer-reviewed articles.  I took a class where we reviewed and critiqued a number of these papers where we were taught to look at the data and not just read the abstract.

I was, in my opinion, taught well in the Master's Program in Public Health at the Texas A&M Health Science Center's School of Rural Public Health.  Ignoring the A&M v. UT rivalry and any competitive issues I have with UTA, my reading of this paper is founded on this one premise;  I am skeptical about EVERYTHING claimed to be peer-reviewed.

The data, methods, findings, and conclusion presented have to meet with what I know to be true.  If, for example, you present statistical data where the number "1" is in your Confidence Interval (CI), I am going to question the rest of your work.

Same goes for posting a graphic where you use the colors red and yellow and tell me that green indicates "no concern."  I instantly morph into skeptic mode.

Source

Okay, so I look at that graphic and think that it is kind of biased and manipulative.  That's my opinion.  I am speculating because it is plausible.  I want to move away from my opinion and try to look at what Dr. Fontenot claims is "powerful argument for continued research."  He put his name on the paper, I put my name to this blog.

Fight!

Round One: Line 117

Analytical tests were conducted to detect volatile and semi-volatile compounds identified as contaminants of concern in a congressional report on hydraulic fracturing fluid components, and to detect arsenic, barium, selenium, and strontium.  These constituents are often included on lists of natural gas extraction waste components

Here is what the congressional report tells us:

Source

Line 117 of the report is important because it tells us what they looked for:

• VOCs (Volatile Organic Compounds)
• Semi-VOCs (Semi-volatile organic compounds)
• Arsenic (heavy metal)
• Barium (heavy metal)
• Selenium (heavy metal)
• Strontium (mineral)

They also tested for, according to line 175:

• Methanol
• Ethanol
• Total dissolved solids (TDS).  

Of these components, only methanol appears on Table 1 of the congressional report they cite.  Basically, and this is important, what they UTA looked for was what went into the hole (fracturing fluids) and what came out of the hole (natural gas extraction waste components).

Why is this important?  Because of what the authors conclude:

Concentrations that exceed the MCL occur only in close proximity to natural gas wells suggesting that mechanical disturbances or localized groundwater withdrawals near natural gas wells could play a role in elevated constituent concentrations.

The authors then go on to rule "localized groundwater withdrawals" out, stating:

If regional drought or widespread public water withdrawals were the cause of elevated constituent levels, then the geographic localities of MCL exceedances would be more evenly distributed throughout the study area, rather than in close proximity to natural gas wells. Additionally, regional lowering of the water table should have resulted in similar constituent concentrations in these aquifers during historical periods when groundwater withdrawal rates were even higher than present levels.

That leaves only "mechanical disturbances" as the culprit.  Here is what the authors say about that on line 325:

...mechanical disturbances (high pressure fluid injection, mechanical vibration, etc.) associated with natural gas extraction activities could be the cause of elevated levels of TDS and arsenic

And on line 404:

We suggest that episodic contamination of private water wells could be due to a variety of natural and anthropogenic factors such as the mobilization of naturally occurring constituents into private wells through mechanical disturbances caused by intense drilling activity, reduction of the water table from drought or groundwater withdrawals, and faulty drilling equipment and well casings.

Followed on line 406 with this:

The geographic locations of elevated constituent levels in our study are consistent with the notion that mechanical disturbance of private water wells and industrial accidents (e.g. equipment failure, faulty well casings, fluid spills, etc.) are more frequent in areas where natural gas extraction is active.

Now when I read all of this, I understand the culprit to be either:

• Mechanical disturbances (high pressure fluid injection, mechanical vibration, etc.)
• Industrial accidents (e.g. equipment failure, faulty well casings, fluid spills, etc.)

So in looking at the graphic they use...:

Source

...and counting the number of red and yellow dots, I would expect to see contamination in groundwater wells near active natural gas extraction sites.

And that is what the authors tell me in this graphic:

On line 416 the authors state:

At a minimum, these data suggest that private wells located near natural gas wells may be at higher risk for elevated levels of constituents than those located further from natural gas wells

My question is this; does the data support that suggestion if you look at all the data available?


Next post: Part 4

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