(Figures 1-3, modified for size, are above. #1- uppermost, #2 - middle, #3 - bottom. They are from the USGS, Circular 1245. Links for Figures 4-5 are below the text document and are from the Piedmont Environmental Council.)Uranium Mining and Extreme Flooding in Virginia
The Need for a Sediment Transport/Water Quality Model and PMP Failure Analysis
by
Thomas M. Leahy
July 1, 2009
Extreme Flooding in VirginiaFigure 1 is a map of the United States showing the location of approximately 23,000 past and present USGS stream flow gauges. Figure 2 is the same map showing only those stream flow gauges (about 3,000) that have recorded extreme flooding events. The screening criteria that the USGS used to define an extreme flooding event was 100 to 300 cubic feet per second (cfs) per square mile for small water sheds (less than 1000 square miles) and 50 to 100 cfs per square mile for large watersheds (1,000 squaremiles and greater). The average stream flow for watersheds in Virginia and adjacent states is about 1.0 cfs per square mile. Therefore, Figure 2 shows the locations where stream flows have been recorded that were at least 50 to 300 times greater than the average normalized stream flow in Virginia.
For the contiguous 48‐states, Figure 2 shows that other than the west coast, extreme flooding occurs mostly in the southeast quadrant (south of the 40th parallel and east of the 100th meridian). Moisture for the precipitation that fuels these events is provided by the warm waters of the Gulf of Mexico and the Atlantic Ocean. These floods can be represented by three primary clusters.
The first is the central mid‐west and lower Mississippi Valley which includes eastern Kansas and Oklahoma, Missouri, Arkansas, Louisiana, Mississippi, and western Tennessee and Alabama. These regions have been nicknamed Tornado and Dixie Alleys due to the frequency and magnitude of tornados that result from intense thunderstorms known as super-cells, formed by the collision of cool dry Canadian air with warm humid Gulf of Mexico air.
The other two clusters of extreme flooding events are southern Texas and the eastern ridge of the Appalachian/Blue Ridge Mountain chain from Georgia to Maine, including a distinct concentration in Virginia. The USGS determined that these regions are prone to extreme flooding because topography provided by mountain ranges and escarpments can rapidly lift moisture laden air into the cooler upper atmosphere:
“Within the eastern conterminous United States, the pattern of large flows closely corresponds to the proximity of subtropical moisture derived from the Gulf of Mexico and the Atlantic Ocean. Finer‐scale patterns within this region, however, are clearly linked to topography. Orographic lifting of moisture from the Gulf of Mexico triggers convective instability and has caused concentrations of large floods at topographic features such as the Balcones Escarpment in south central Texas, the Ozark Mountains of western Missouri, and along the eastern edge of the Appalachians on the eastern seaboard. The important role of topographic relief is also illustrated by the lack of exceptional discharges in Florida, and along the coastal plain of the southern and eastern tier States. Despite being closest to the moisture sources and subject to frequent landings of major hurricanes, these relatively flat areas have few stations that have recorded flows exceeding the large‐flow criteria . . .”
--Large Floods in the United States: Where They Happen and Why, USGS Circular 1245, 2003, p.9. Emphasis added.
Figure 2 also shows that there are very few extreme flow events in the western states or in the northern mid‐west. Where they do occur, they are mostly confined to very small watersheds. This is the result of a lack of an available moisture source and/or cooler air temperatures, both of which limit the moisture content in the air.
Probable Maximum Precipitation [PMP] in VirginiaThe screening criteria for identifying the extreme flows depicted in Figure 2 ranged from 50 to 300 cfs per square mile. However, depending upon duration, a Probable Maximum Precipitation (PMP) event in Virginia and surrounding areas will deluge an area with 1,000 to 7,000 cfs per square mile.
Figure 3 is the same as Figure 2, except that the locations of storms with precipitation approaching the PMP have been shown. Figure 3 also includes the location of the proposed Coles Hill uranium mine, in Pittsylvania County, VA. In the eastern US, the locations of the near‐PMP events mimic the location of the extreme flooding events identified by the USGS: Tornado and Dixie Alleys, southern Texas, and the eastern ridge of the Appalachian and Blue Ridge Mountains.
In fact, Figure 3 shows a string of at least 8 near‐PMP storms east of the Blue Ridge Mountains from North Carolina to Maine. These events occurred along a corridor that cuts a path right through the uranium ore deposits in Pittsylvania County and the ore deposits in four counties west of Fredericksburg.
Two of the storms occurred in Virginia ‐ one in 1969 in Nelson County about 60 miles from the Pittsylvania uranium deposits (Figure 4), and the other in 1995 in Madison County, one of the four counties west of Fredericksburg where uranium ore deposits have been identified (Figure 5).
The Need for a Sediment Transport and Water Quality Model and Failure AnalysisAs a consequence of the topographic relief provided by the Blue Ridge Mountains and the subtropical moisture provided by the Gulf of Mexico and the Atlantic Ocean, the Piedmont region in Virginia just east of the Blue Ridge Mountains is prone to extreme flooding and has a much higher likelihood of experiencing catastrophic precipitation events than many other areas in the country. However, this is also the same location of the uranium deposits in Pittsylvania County and west of Fredericksburg.
Stakeholders concerned about the potential impacts of uranium mining have asked to be shown locations and examples of uranium mines and mill tailing cells that occur in areas that have similar climate, geography, and population density as Virginia. This may be problematic ‐ there may not be any other locations where uranium mines and milling operations, an unlimited source of hot humid air, topographic/orographic lifting potential, and high population density all intersect.
Even if a uranium mine and milling operation located in a relatively wet climate (i.e., 45‐inches per year of precipitation) could be identified, that location might not be prone to extreme precipitation events due to its particular meteorological and physiographic characteristics. It is even less likely that a uranium mine or milling operation will be indentified that has ever experienced a PMP event similar to the two that have occurred in Virginia (about thirty inches of rain in six‐hours).
Therefore, it is important to assess what the potential consequences would be if a storm similar to the Nelson County or Madison County storms were to strike a mining and milling operation and transport a significant load of mill tailings downstream to the receiving rivers and reservoirs. This will require an engineering study that includes a sediment transport and water quality model.
The model must be able to accept as input, various precipitation events ranging from severe hurricanes and nor’easters that strike Virginia relatively frequently to a probable maximum precipitation (PMP) event. The modeling of the fragmentation of a mill tailing dewatering facility, storage area, or confining cell will be a difficult task, subject to much debate. So, initially, the model should be designed to accept as input, assumptions of various amounts of mill tailings that might be released as the result of a catastrophic precipitation or flood event that would strike the proposed Cole’s Hill mining operation.
The model would then predict the downstream transport and fate of the mill tailings in terms of location and quantity beginning with the Banister River, through Kerr Reservoir, through Lake Gaston and Roanoke Rapids, and downstream through the Roanoke River and flood plains, and into Albemarle Sound.
After the model has determined the location and quantity of the transported mill tailings, a water quality component will predict the increased radioactivity and other contamination that will result in the downstream waters for any given amount of mill tailings released. The water quality parameters that will be considered are gross alpha, gross beta, radium isotopes, radon, and uranium. Other toxic substances typically associated with mill tailings will also be considered.
The model will also include an assessment of how long the increased radioactivity or other contamination would persist given normal weather and flow patterns.
Figure 4:
http://www.pecva.org/anx/index.cfm/1,557,2133,0,html/Properties-with-Former-Uranium-Mining-Leases-and-Downstream-Water-Supplies-Southside-RegionFigure 5:
http://www.pecva.org/anx/ass/library/19/downstreamflow_counties_wtr.pdf
An underground container that holds about half of the world’s supply of radium may be leaking into groundwater in northwestern Niagara County, an advisory group to federal regulators warns.
The Army Corps of Engineers, the federal agency responsible for investigating an area in the towns of Lewiston and Porter holding leftovers from the Manhattan Project, has found uranium contamination beneath ground level in portions of a former federal weapons site.
But corps officials insist there are no leaks in a 10-acre cell, known as the Interim Waste Containment Structure, constructed in the mid- 1980s on the 191-acre Niagara Falls Storage Site as a temporary container for various radioactive wastes and other radiological materials.
Those substances include uranium and about half the world’s supply of radium.
Joseph A. Gardella Jr., chairman of the Lake Ontario Ordnance Works Restoration Advisory Board — a group of residents, academics and industry professionals—believes the issue plays a major role in the ultimate decision on the future of the radioactive substances buried in Niagara County.
“The big question is: If the storage site is already showing some evidence of wear,” Gardella said, “isn’t that something that we should be concerned about?”
Input from the advisory board, which includes faculty from area universities with technical expertise, has been minimized by the corps for the past several years. Early last year, corps officials said the group no longer met the corps’ guidelines.
Despite being virtually ignored, advisory board members have continued to closely monitor issues related to both chemical and radiological contamination at the site.
“It’s really important for the community to be paying attention,” said Gardella, a chemistry professor at the University at Buffalo with decades of experience working on environmental issues in Western New York.
“If you’re minimizing the potential for leaks,” he continued, “that starts to factor into the argument
about the stability of the temporary storage site. And the stability of the storage site is going to be critical in arguing whether [the radioactive material] stays here or not.”
Neither the Corps of Engineers nor the advisory board has said it believes conditions constitute a public health risk at this time.
But the results of a plethora of studies and risk analyses are the building blocks for the final decision on whether to keep the radioactive materials buried in Western New York or to ship them somewhere else for disposal.
Since 1997, when Congress passed responsibility for cleanup of former Department of Defense sites to the Corps of Engineers, the agency has been investigating conditions at the former Lake Ontario Ordnance Works, which includes the Niagara Falls Storage Site. The former ordnance site began with TNT production prior to World War II on a portion of 7,500 acres in Lewiston and Porter. Work on the country’s atomic project officially began there in 1944.
The materials buried in the waste cell come from ore mined in Africa and brought to the United States.
They are unique in a global sense because of the concentration of uranium that was initially found within them, said William L. Boeck, an advisory board member and professor of physics and computer and information sciences at Niagara University.
While the radioactive substances in this case are naturally occurring— as opposed to being the by-products of a nuclear reactor — they are still “more than 10 times richer than anything that’s been found on earth,” Boeck said.
Between 30 and 65 percent of what was mined was uranium, a concentration far greater than anything found in current mining activities in places like Canada and Australia, Boeck said.
“There is nothing like this left on earth,” he said.
Uranium, a high energy and unstable radioactive material, changes into radium as part of a natural decay process.
The corps plans additional investigation related to the radioactive contamination on the Niagara Falls Storage Site. The agency has said it is currently evaluating the available options that would address site contamination.
Sampling could begin as early as this fall, Michelle Rhodes, acting program manager for the project, said via e-mail.
The corps said last year that it spends about $3 million annually on cleanup efforts at the storage site.
Though the additional work is planned, the head of the advisory board is raising questions about the quality of the agency’s study of the radiological contamination.
Gardella contends the corps “didn’t do anything scientific” in evaluating the underground uranium levels.
“I’m not saying they’re incompetent, but this isn’t world-class science and engineering,” Gardella said.
Corps representatives, in a public presentation last month, said their study indicates “no short-term competency issues” related to the interim containment cell.
Study of the contamination shows “no increasing trend in concentration of uranium that would be indicative of a breach,” Rhodes said in her e-mail.
The sides also differ on what uranium levels they accept as typical for the area, also known as “background” levels.
For more than a year, the advisory board has called on regulators to dig into the cell as part of their study. That is the only way to know if groundwater has infiltrated the structure, the board contends.
Corps officials have refused, saying that the procedure would be unsafe for workers who conduct the analysis and that they have “minimized, to the extent possible,” the limitations of the survey methods they did use.
“There is no need to compromise the integrity of the [cell] cap for data not needed at this time,” Rhodes said.
Boeck, the Niagara University professor, disagrees.
The cell boundary is about 50 feet from an area known as the Central Drainage Ditch, which drains into Lake Ontario, he said.
Corps officials say if data is needed later, possibly if the agency decides to remove the radioactive material, the intrusive sampling can be done then.
Gardella said the corps’ analysis— and resulting determination that there is no leak — is based more on computer simulations than actual data. He also said he is not diminishing the challenges that exist if the radioactive storage cell is penetrated; corps officials have not provided a list of pros and cons on the issue, he said.
Performing the intrusive action is necessary if anyone ultimately wants to know about conditions at the site, Gardella said.
The board believes the uranium contamination may have spread outside the storage site property. An investigation of whether it has spread is planned as part of the work that could begin in the fall.
Any discussion about a final decision on what happens at the Niagara Falls Storage Site is done in terms of years, not months.
“To the people in the community,” Gardella said, “the question is, ‘Is it going to be left there or is it going to be excavated and taken out?’ ”
http://www.buffalonews.com/cityregion/story/738086.html