An analysis of drinking water sampled from three homes in Bradford County, Pennsylvania revealed traces of a compound commonly found in Marcellus Shale drilling fluids, according to a study published on Monday.
“This is the first documented and published demonstration of toxic compounds escaping from uncased boreholes in shale gas wells and moving long distances” into drinking water, said Susan Brantley, one of the study’s authors.
The study, published in the Proceedings of the National Academy of Sciences, found traces of the chemical compound 2-BE in the wells. The compound is often found in drilling and fracking fluid, as well as paint, cosmetics and fluids, but the authors identified drilling as the most probably source. According to the study, the contaminants “migrated laterally through kilometers of rock at shallow to intermediate depths” to reach the wells.
Wellbores the source of contamination
We should be clear about the source of contamination in the study. The oil and gas industry can hold on to its big lie about fracking and water contamination. That’s the one that says that, because fracking occurs thousands of feet below drinking-water aquifers, the drilling chemicals that are injected to break up rocks and release the gas trapped there pose no risk. While the residents of Pavillion, Wyoming would disagree, the fracking process itself is not the source of contamination in this case.
What we’re talking about in this case is a lack of wellbore cement casing integrity, a common problem in oil and gas drilling. The researchers suggest that the wells, which were established in 2009, were constructed with a protective intermediate casing of steel and cement from the surface down to almost 1,000 feet. But below that depth the wells lacked the protective casing, putting them at greater risk of leaking their contents into the surrounding rock layers.
According to the researchers, it is likely that fracking fluid escaped the borehole while crews were first drilling the gas well and migrated over time through the rock subsurface to the wells.
How does Montana regulate casings and wellbore depth?
Montana has some regulations regarding cement casings, but it is unlikely they would prevent the kind of contamination described in this study. Montana does not require that drillers meet American Petroleum Institute Standards for well casings, which include:
- Conductor casings should be cemented to the ground surface
- Intermediate casings should extend above aquifer and hydrocarbon zone
- Production casings should be cemented at least 500 feet above the highest formation where fracking is performed
- Surface casings should be cemented to a pre-determined depth across all aquifers and below the deepest aquifer
Instead, Montana standards do not address these standards for conductor casings, intermediate casings, production casings or surface casings.
What it means for us
The study released this week is important because it confirms that a lack of wellbore integrity can cause water contamination miles from a fracking site, and it demonstrates the clear risk to wellbores that are not properly regulated.
The Administrative Rules of Montana do not properly regulate the integrity of wellbores. This is critical for Montana residents to understand, and I encourage all of you to read the regulations for yourself. You can find them in the following sections of the Administrative Rules of Montana: 36-22-1001, 36-22-1002, 36-22-1416, 36-22-1010, 36-22-1011, 36-22-1013, 36-22-1106, 36-22-703. There is a good summary of the basic provisions of these laws at Law Atlas (click on map of Montana to see summary).
The bottom line, and stop me if you’ve heard this before, is that Montana communities need to take control of the regulation of oil and gas drilling. The American Petroleum Institute has set forward standards for protecting wellbore integrity, which Montana law does not follow. It is worth noting that Pennsylvania (click on Pennsylvania map), the site of the contamination in this week’s study, has adopted the American Petroleum Institute standards subsequent to 2009, when the wells in question were established.
It’s your water. Take action to protect it.