Dr. Hannan LaGarry teaches geology, biology, statistics, and research methods at Oglala Lakota College on the Pine Ridge Reservation. Geology is his main area of study, and he put his geology knowledge to work analyzing borehole logs, drillers' notes, maps, and other data released by Powertech/Azarga last year in its application to the Nuclear Regulatory Commission Atomic Safety and Licensing Board to conduct in situ recovery mining for uranium in the southern Black Hills.
The NRC-ASLB yesterday released Dr. LaGarry's written supplemental testimony, given November 21, 2014. Dr. LaGarry's analysis finds a number of holes in the ground that, claims the scientist, poke holes in Powertech/Azarga's claims that their uranium mining poses no risk to local ground water.
Reviewing drillers' notes from 4,177 boreholes out of 7,515 boreholes logged, Dr. LaGarry finds...
- 140 open, uncased holes
- 16 previously cased, redrilled open holes
- 4 records of artesian water
- 13 records of holes plugged with wooden fenceposts
- 6 records of holes plugged with broken steel
- 12 records of faults within or beside drilled holes
- 1 drawing of 2 faults and a sink hole within a drilled transect 7 notations “do not record this value on drill hole maps”
- 2 notations “do not return this to landowner”
- 63 redacted borehole logs
LaGarry says that the open boreholes and those capped with wood (which rots) and broken steel (which rusts) could allow mining fluids and contaminants to move through the rock strata into unmined areas. He concludes, "There is no reasonable expectation that confinement remains in drilled areas."
LaGarry says the presence of artesian water reveals the possibility that subsurface contaminants from mining operations could reach the surface and contaminate the Cheyenne River and its tributaries.
And what's that about faults?
During hearings before the ASLB in August of 2014, Powertech repeatedly asserted that faults and sinkholes were not present in the license area, and that the license was somehow unique in that regard. In my previous testimony, I offered the expert opinion that faults were almost certainly present, and the license area was most likely crossed by numerous faults. The observations I document herein demonstrate that my previous expert testimony was correct, and there are numerous faults present in the licensed area. Likewise, the drillers’ notes document a sinkhole along a drilled transect associated with two closely spaced faults also intersecting the drilled transect. Sinkholes typically form along faults, as the fault allows the initial penetration of acidic surface waters, which then dissolve a conduit through the rock which eventually forma a cave that subsequently collapses to for the sinkhole [Hannan LaGarry, written supplementary testimony to Nuclear Regulatory Commission Atomic Safety and Licensing Board, 2014.11.21, p. 3].
NRC staff evidently accepted Powertech/Azarga's assertions of environmental safety based on a spot check of three dozen borehole logs, with no apparent mention of the drillers' notes. LaGarry schools the NRC on basic math:
The minimum number of data points for a statistically valid and meaningful sample is generally 10%. In the Powertech instance the minimum acceptable sample size would be a randomly selected sample of at least 175 borehole logs. Based on the recent disclosure of over 4,000 previously withheld borehole logs, the appropriate sample would be 10% of the entire set, or about 575+ borehole logs checked. NRC Staff presents no basis for its so-called “random” selection. Without such information, professionals in my field cannot accept such assertions where it is possible that the limited data set resulted in poor methodology that is the hallmark of modern junk science. Having examined only 37 data points out of thousands available, NRC would have failed my Math 123 Introduction to Statistics class. None of my student researchers would be allowed to publish or present their research findings had they made such a fundamental error [LaGarry, 2014.11.21, p. 5].
Powertech/Azarga has contended that its in situ recovery mining project poses no threat to water quality in the Black Hills and the Cheyenne River watershed. Dr. LaGarry says we shouldn't be so sure.9 comments