The report concludes that 90 percent of the water in the aquifer is 10,000 to 35,000 years old and that it collected there during the ice ages.
The report also states that the current recharge rate of the aquifer is 2,600 to 3,600 acre-feet per year, substantially less than the previous USGS estimate of 4,800 acre-feet per year.
Most important, at least to the Hopi, is that the USGS draft report shows for the first time that Peabody is taking out more water than is being naturally recharged.
The draft report, Masayesva says, is an important development in the long series of studies on the aquifer.
But so far, the USGS report remains in draft form, in part because of extensive comments provided by Peabody, which helped pay for the survey. The company conducted its own study using the same techniques as USGS and concluded that the recharge rate is much higher than USGS's draft report, according to Gary Melvin at Peabody.
In fact, Melvin says the Peabody data shows the recharge rate to be near predictions in USGS models developed in the early 1980s. Peabody's data has been forwarded to USGS for consideration in the agency's final report, Melvin says.
"We have yet to see anything that would cause us any concern or lead us to change any of the assumptions in our earlier studies," Melvin says.
The Hopi, however, claim they don't need definitive proof to shut down Peabody's wells.
Masayesva says the tribe's obligation under federal law is to simply show that there is a "threat" to the groundwater resource.
Once that threat is shown, the federal government--under its trust responsibility to Indian tribes--is required to conduct the studies and determine whether Peabody is depleting the aquifer.
And in this case, Masayesva says, the government doesn't have to prove damage, but only that Peabody poses a danger to the aquifer. The lower standard is a result of the lease language required by Stewart Udall: "Should the Secretary of Interior determine, at any time, that the operation of the wells by [Peabody] is endangering the supply of underground water in the vicinity or is so lowering the water that other users of such water are being damaged, he may...require Peabody Coal Company, at its sole expense, to obtain water for its mining and pipeline operations from another source that will not significantly affect the supply of underground water in the vicinity."
Masayesva and Hopi water attorneys believe the clause gives Bruce Babbitt a powerful lever, if he wants to pull it.
"Babbitt has a trust responsibility to protect the natural resource, and he has discretionary authority to make the decision requiring Peabody to stop using groundwater without calling for absolute proof on the part of the Hopi," Masayesva says.
Hopi water officials say there are plenty of scientific reports that show the groundwater is being depleted by Peabody and that Hopi supplies are damaged.
Hopi hydrologist Ron Morgan points to a series of USGS reports that clearly show Peabody's pumping is directly related to declining water levels in Hopi municipal wells. Water levels in Keams Canyon wells, for example, have fallen more than 160 feet since Peabody began pumping.
USGS hydrologist Gregory Littin says about half of that depletion at Keams Canyon can be attributed to Peabody's groundwater pumping.
Despite such evidence, the Department of the Interior has refused to act. Hopi attorneys' requests have gotten nowhere with Interior. (Babbitt's press secretary, Mary Helen Thompson, promised on several occasions to get "somebody" to talk about the issue with a reporter, but she didn't.)
Interior's silence on the issue is a bit surprising, considering that the department itself has displayed concern over Peabody's use of groundwater.
Former interior secretary Manuel Lujan rejected Peabody's application for a mining permit at the Black Mesa Mine in 1990 because of groundwater concerns. Instead, Lujan issued an interim permit to Peabody, pending groundwater studies.
Interior's refusal to issue a mining permit stems in part from a 1990 U.S. Environmental Protection Agency report that concluded the use of groundwater for the coal-slurry line "is not an environmentally preferable alternative."
Peabody claims a 1993 water study funded by the two tribes and Peabody conclusively proves there has been no long-term impact to the aquifer. Peabody asked Interior's Office of Surface Mining to issue a permit based on that report. The Hopi vehemently objected to the validity of the study and to the fact that they were not allowed to comment on the report before Peabody sent it to the Office of Surface Mining.