Peabody report says no damage to N-Aquifer likely
Managing coal and water resources on the Navajo and Hopi Reservations has become a balancing act. It is no secret that both tribes rely heavily on coal revenue for tribal programs and operation. But recent visible declines in springs and streams—on the Hopi Reservation in particular—have called into question the practice of using another precious resource—water—to slurry that coal to the Mohave Generating Station in Laughlin, Nevada, a distance of 273 miles.
The Peabody Group operates two mines—the Kayenta and Black Mesa mines—under lease agreements with the tribes, and Peabody Coal Company also pays the tribes for the use of water from the N-Aquifer (Navajo Aquifer). The N-Aquifer is the only source of water for the Hopi mesas.
According to the Black Mesa Trust, a local, non-profit organization that has spearheaded the movement to end the slurry, Peabody currently pumps water from the aquifer at a rate of 83,000 gallons per hour. “You could fill 945,560,356 fifty-five gallon barrels with this water,” said Vernon Masayesva, Director of BMT, in an earlier interview. “If each of those barrels were placed end to end, they would reach to the moon and back three times. You cannot pump billions of gallons of water very year in a desert without serious consequences.”
Masayesva believes that there may be problems not only with continued water supply for the Hopi people, but also with the structural integrity of the aquifer itself.
But according to a recent study released by the Peabody Group, “using aquifer water...will not significantly affect the integrity of the 7,500 square-mile aquifer or surrounding community water supplies.” The study, prepared by two independent hydrologic firms and reviewed by an independent expert, follows on the heels of a report released by the National Resources Defense Council (NRDC) in November, which stated that the aquifer is “exhibiting symptoms of decline and indications of damage.”
The study has renewed Peabody’s faith in their computer modeling systems, which have also been called into question by groups like the Black Mesa Trust, which claim that the models are outdated and cannot be substituted for on-site studies.
“We used the most extensive data available and developed the best modeling tool yet,” says Frederick Palmer, executive vice president for legal and external affairs fro the Peabody Group. “The results confirm that the fraction of water being used is insignificant when you put the aquifer’s vast size into perspective. “[The aquifer] is not that delicate; it is very, very robust.”
Brian Dunfee, Manager of Environmental Engineering for Southwest Operations for the Peabody Group, says that this updated, three-dimensional model allows scientists to see the vertical as well as the horizontal water flow in the aquifer, but even with the improvements in the model, the results still match Peabody’s original predictions.
“The 3D model is the better model, but our conclusions are still the same,” he says.
Dunfee also points out that Peabody operates six wells around the leasehold to monitor impacts of pumping. These results are matched up against the computer models. While the old models were beginning to demonstrate inaccuracies, he says, the new models have rectified the problems. “The predicted outcomes (from the computer models) now line up with the actual outcomes (from the wells).”
Dunfee says that while Peabody is still reviewing the NRDC findings, he believes that they may not have had the tools to make accurate measurements.
“The NRDC models don’t differentiate between the percentage of water used by Peabody and the percentage of water used for municipal uses in places like Kayenta, so the impacts of mining alone cannot be assessed,” he says.
In addition, says Dunfee, there is a possibility that the NRDC was given some bad information. While the NRDC reported that water in one of the wells was down to one foot from the top of the aquifer, which violates the Office of Surface Mining’s Cumulative Hydrologic Impact Assessment, the regulatory body that oversees operations likes Peabody’s. But Dunfee says that the United States Geological Survey reports that the water level is 400 feet above the top of aquifer, within acceptable limits.
Palmer points out that while this latest study was prepared at Peabody’s request, they take their responsibility for the aquifer very seriously, constantly monitoring its condition.
Still, organizations like the Black Mesa Trust believe that other factors, like population growth, must also be considered. In the next 40 years, population in the Black Mesa area is expected to increase from 68,000 to 234,000. Added to a probable increase in the standard of living, water use could increase dramatically, from the current 3,800 acre feet per year, to 25,250 acre feet per year.
Palmer does not believe, however, that population growth will have that much of an impact on the aquifer. “I take comfort in the fact that we are only taking 1/10 of 1 percent of the total water in the aquifer. That’s not a lot of water.”
According to a Peabody press release, that is less than half of a beverage can, removed from a 55-gallon drum. While Palmer does not doubt that there are visible differences in the springs and streams, he does not believe that that difference is necessarily due to Peabody’s use of the water.
“There is a lot of anecdotal information used to say that there is a substantial difference in the springs and streams,” he says. “But it depends on what timeline you are using, what the rainfall in the area has been, what the water patterns are. All sorts of things can impact groundwater from year to year.”
Peabody can continue its mining operations for about another 25 years, says Palmer, and can continue to slurry that coal to the generating stations.
“We have mined about half of the 670 million tons of coal available. Coal delivery to the plants is about 13 to 14 million tons per year,” says Palmer, pointing out that since the generating stations can be updated to meet changing environmental standards, they can run “forever.” “All the coal will be mined,” says Palmer.
Neither Leonard Selestewa nor Vernon Masayesva of the Black Mesa Trust could be reached for comment on the latest Peabody report before press time.