By Steve Finch
Hydrologist
My company, John Shomaker & Associates Inc., presented the findings of a study showing that the U.S. Bureau of Land Management (BLM) drilling plan for Otero Mesa could jeopardize the aquifer beneath the mesa.
That conclusion reflected the fact that the BLM plan "makes no special provisions for protection of ground-water resources" including existing and proposed public water wells.
I was the author of the study, which was commissioned by the Otero Mesa Coalition and the Campaign To Protect America's Lands. It found that the "water supply beneath Otero Mesa is potentially vulnerable to contamination by the BLM proposed oil and gas development because of the proximity of existing water supply wells and the porous nature of the regional aquifer."
The report explained why the BLM plans for permitting oil and gas development lack sufficient protective measures. The aquifer beneath the Otero Mesa and Salt Basin areas is highly fractured limestone, which is susceptible to contamination resulting from the injection of oil- and gas-related waste into underlying rocks or from spills and leaks from pits and materials on the land surface.
The report emphasized that the potential risks to ground water from drilling are not strictly theoretical. Similar drilling-related problems have been documented with polycyclic aromatic hydrocarbons (PAH) pollution of the San Juan Basin in New Mexico, manganese and sulfur contamination of the aquifer tapped by the city of Artesia water-supply wells, and brine contamination of the Ogallala Aquifer in southern Lea County in New Mexico.
At the time, I said: "The proposed BLM plan puts in place no special provisions for protection of ground-water resources, which is to say the public water supply. The vulnerability of the aquifer under the Otero Mesa can be inferred from fracture mapping, the direction of ground-water flow and the proximity of water supply wells to the BLM land proposed for oil and gas developments."
After the study came the assertions of those who didn't like the idea of anyone pointing out the flaws in the BLM plan.
For example, the factually unsupported suggestion that people have nothing to fear came in BLM State Director Linda Rundell's commentary "Drilling Today Far Superior to Past."
Rundell states that "more than a hundred wells had been drilled in Sierra and Otero Counties prior to 2004, with no contamination of ground water or other freshwater resources."
As a hydrologist specializing in New Mexico issues, I know that is a completely untenable claim. I know that none of those drill sites have been investigated for ground water contamination. This shows why this important debate needs scientific study— not assertions.
Rundell also states that "BLM mandates that oil and gas drilling activity be isolated from aquifers by issuing casing and cementing requirements that are specific to each well."
But how does that apply to the highly fractured and unstable rock commonly found on Otero Mesa? In fractured rock, lost circulation of drilling fluids or cement can limit the ability of the rock to isolate and protect the fresh water aquifer.
The fractured rock areas on Otero Mesa have been mapped and documented by a geologist from the University of Texas, but the BLM has failed to acknowledge these studies and the implication of protecting the fractured rock aquifer from oil and gas drilling.
Finally, Rundell, in reference to protecting ground water from surface spills and leaks, states: "BLM requires lined pits to hold these liquids or fully enclosed systems near water resources."
We know from on-the-ground scientific research that a substantial part of the Salt Basin (Otero Mesa) has little to no soil cover, with fractured rock exposed at the surface. Blasting rock to make a below-grade pit provides the worst possible surface for a liner, lending the inevitable liner failure and loss of contained fluids (brine, oils, etc).
On the other hand, Rundell is 100 percent correct when she says that oil and gas drilling today is far superior to past industry practices. But so is our scientific understanding of freshwater aquifers and the steps needed to protect them.
In a state with limited water resources, can we afford putting this irreplaceable resource at risk?
Steve Finch is vice president, senior geochemist and hydrologist at John Shomaker & Associates.
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