Shale Gas Development and Water Quality: Best Practices Can Mitigate Risks to Underground Aquifers and Water Wells

If you follow the news on the development and production of natural gas and oil from shale rock buried deep underground, you have probably seen or read stories about the potential risks to fresh water supplies posed by hydraulically fracturing (“fracing”) and producing shale gas.  You may have heard that the New York State Legislature has imposed a temporary ban on shale gas development anywhere in the watershed to New York City, and that other states and the federal government are contemplating similar measures aimed at protecting our fresh water supplies and public health.   You may also have heard anecdotes about people living near shale development areas, who one day found their water contaminated by methane or other pollutants.  And, you probably have heard other stories like these and may well be left with the impression that shale gas development poses a grave danger to our nation’s water supply.  Indeed, an HBO documentary was broadcast on this very topic elevating a great deal of concern.

Here at Pace Global, where we advise the Marcellus Shale Coalition and many other companies involved in shale gas development, we adhere to an uncompromising priority of protecting our nation’s water resources so any concern in this area requires prudent consideration and professional assessment.   Risks should be identified and strict policies and procedures should be implemented.   However, these policies and procedures should be based on scientific assessment not on unfounded fear.  Pace Global has studied these concerns  and we conclude that science and operating history of hydraulic fracturing provide sufficient evidence to demonstrate that use of best practices in shale gas development alleviate those risks that have been so widely publicized.   Note that I use the term “best practices”.  Pace Global strongly supports the development of operating protocols that require, through regulatory oversight, the use of   best practices that are based on science and informed engineering practices of this sector.

We cannot compromise our water resources but we also cannot be blind to the immense economic and security benefits that shale gas holds for our nation.  Prudence and maturity must prevail in this discussion.

To put some of these issues in appropriate context for you, today I am going to discuss the underground aspects associated with shale development, leaving surface water management aspects for another edition.  The primary fears espoused by fracing opponents include:

1.     Rock fractures induced through fracing could penetrate a fresh water aquifer, contaminating it with frac fluid and possibly natural gas.

2.     Frac fluid or natural gas could enter these aquifers and thereby contaminate the fresh water supply as it is transported up (or down) the wellbore to the surface.

On the first issue, it is important to understand that the shale gas formations targeted for development are located a mile or more below where the aquifers are that we all seek to protect.  Multiple layers of impervious rock, stacked a mile high, lie undisturbed between the fractured shales and the aquifers.  Over the course of the last 60 years, tens of thousands of hydraulic fractures of deep zones like this have never led to water contamination because of the massive physical barrier between the aquifer and the target zone.

When one looks at the history of the practice of hydraulic fracturing, the deep geology of shale itself, the engineering mechanics of the fracing process and the regulatory barriers to improper practices, we are confident that the practice of hydraulic fracturing of deep shales does not present a threat to underground aquifers.

With regard to the second issue posed above, several background points are important to note.

• Natural gas occurs naturally in many shallow rock formations and in the top few feet of soil and rock beneath our feet.  These shallow reservoirs were our first sources of natural gas, dating back to the early 1800s, throughout the Appalachian Basin.
• This gas in shallow rock strata can easily migrate into private water wells because most water wells are uncased, meaning there is no physical barrier between the rock face of the wellbore and the water flowing through it to the surface.   The vast preponderance of press reports on water wells “going bad” in areas where shale gas development is nearby are the result of elevated homeowner scrutiny leading to the “discovery” of methane in the water supply due to uncased wells.
• To prevent such contamination (and loss of product) due to leaky shale gas wells, developers go to great lengths to seal off the wellbore from the surrounding rock.  As shown to the left, multiple concentric layers of steel and cement provide a secure barrier between the exposed rock face in the well and the flowing frac fluid and natural gas.

Can anything go wrong?  Yes, and in some isolated cases it does.  The major culprit in the several confirmed instances of shale gas well “leakage” into shallow soils is inadequate injection of cement in the well.  Such problems are quite rare and can be corrected without any lasting harm to water supplies or the soil.

The memory of the BP Gulf oil spill is fresh in all of our minds — rightfully so.   And, it appears that this catastrophe was caused or aggravated materially by not adhering to “good practices” that were clearly established.   I understand the concern and the need for vigilance.  But we too must be cognizant of the countervailing risks.  Under a separate edition of this blog, I will share with you the economic costs, the generational unemployment and competitive deterioration and the security issues that arise from a practice of flowing billions of dollars to foreign entities and then borrowing those dollars back from other foreign sources.  For me, the realization of this flawed policy model is chilling and I hold ever confidence it will give you pause as well.  So, as with shale gas development and other energy decisions, we must not lose sight of the priority of environmental protection but we must adopt those practices and policies that are prudent and ensure that “best practices” are enforced.  In our next installment on shale gas, we will discuss surface water management and associated risks.