‘Two Major US Aquifers Contaminated by Natural Uranium’

Natural Uranium Contamination in Major U.S. Aquifers Linked to Nitrate: Study

About 2 million people across the Great Plains and California reside above aquifer sites that are contaminated with natural uranium, mobilized by human-contributed nitrate, according to a new study by researchers at the University of Nebraska-Lincoln.

High Plains (HP) and Central Valley (CV) aquifers. The intensity of groundwater contamination via uranium (red) and nitrate (blue) is highlighted in two major aquifers and other sites across the United States. Credit: University of Nebraska-Lincoln

Abstract: Groundwater geochemical data collected from two major U.S. aquifers, High Plains (HP) and Central Valley (CV), revealed naturally occurring groundwater uranium (U) exceeding the U.S. Environmental Protection Agency maximum contaminant level (MCL = 30 μg/L) across 22375 km2 where 1.9 million people live. Analysis of geochemical parameters revealed a moderately strong correlation between U and nitrate, a common groundwater contaminant, as well as alkalinity and calcium [Spearman’s rho (ρ) ≥ 0.30; p < 0.001]. Nitrate is recognized to alter U solubility by oxidative dissolution of reduced U(IV) minerals. Approximately 78% of areas where U concentrations were interpolated above the MCL were correlated to the presence of nitrate (Pearson’s r ≥ 0.5; p < 0.05). Shallow groundwater was determined to be the most susceptible to co-contamination (HP, ρ = 0.46; CV, ρ = 0.52). Together, these results indicate that nitrate, a primary contaminant, should be considered as a factor leading to secondary groundwater U contamination in addition to the recognized role of alkalinity and calcium.

Excerpts from the Introduction: “Uranium (U) contamination of groundwater has been primarily associated with anthropogenic activities such as mining, milling, nuclear testing, and disposal of spent nuclear fuel. However, groundwater U concentrations across the United States exceed the U.S. Environmental Protection Agency (EPA)… The High Plains (HP) and Central Valley (CV) aquifers, two of the largest and most productive aquifers in the world, are among aquifers with high concentrations of dissolved U in groundwater… In addition to being an important source of drinking water, these aquifers are also mined to irrigate 56700 km2 of cropland accounting for 1/6 of all U.S. agricultural annual revenue. Drought has placed an increased reliance on groundwater, impacting not only quantity but also degradation of groundwater quality.

Full paper posted at http://pubs.acs.org/doi/abs/10.1021/acs.estlett.5b00174

Jason Nolan and Karrie A. Weber
Department of Earth and Atmospheric Sciences, University of Nebraska—Lincoln, Lincoln, Nebraska 68588-0340, United States
‡ School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, Nebraska 68588-0118, United States
Environ. Sci. Technol. Lett., 2015, 2 (8), pp 215–220
DOI: 10.1021/acs.estlett.5b00174
Publication Date (Web): July 31, 2015
Copyright © 2015 American Chemical Society

ACS AuthorChoice – This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

Earthquake Strikes SSE of Sendai Nuke Plant

M5.1 earthquake strikes 100km SSE of Sendai, Japan

Centered at 30.8N, 131.1E the quake struck at a depth of about 10km and was felt across the southern tip of Kyushu island, according to Japan’s weather agency.

At the Sendai earthquake monitoring station, the quake registered 3 on Japan’s Seismic Intensity Scale (1 to 7).

Other Significant Earthquakes:

• M5.2, 145km E of Chichi-shima, Japan, 2015-08-17 at 00:45:42UTC depth=7.4km
• M4.0, 1km N of Piedmont, California 2015-08-17 at 13:49:17UTC depth=5.4 km

‘Montana is facing extreme fire conditions’

State of Emergency Declared in Big Sky Country

“Firefighting resources in the state, geographic region, and across Western United States have reached critical shortage levels,” said Montana Governor.

Governor Bullock has issued an executive order declaring a fire emergency in the state of Montana, proclaiming that “Montana is facing extreme fire conditions.”

“Montana is facing extreme fire conditions. This declaration will provide additional resources to the brave men and women fighting these fires,” Bullock said. “As firefighters continue to battle blazes across the state, I encourage Montanans to be aware of fires in their area, obey any evacuation orders that may be issued, and ensure they’re not taking actions that might spark new fires.”

Wildfires are actively burning and extreme fire danger exists across the state of Montana, including the counties of Lincoln, Flathead, Lake, Sanders, Mineral, Missoula, Ravalli, Granite, POwell, Butte-Silver Bow, Anaconda-Deer Lodge, Beaverhead, Madison, Gallatin, Park, Broadwater, Jefferson, Meagher, Lewis and Clark, Teton, Pondera, Glacier, Cascade, Choteau, Judith Basin, Fergus, Petroleum, Wheatland, Golden Valley, Musselshell, Sweet Grass, Stillwater, Carbon, Yellowstone, Big Horn, Treasure, Rosebud, Custer, Powder River, Carter, Fallon and Garfield (42 of the state’s 56 counties), according to the governor’s executive order.

The fires have led to evacuations and road and campground closures.

“Firefighting resources in the state, geographic region, and across Western United States have reached critical shortage levels,” said the governor, “these critical shortages have already necessitated the deployment of international firefighting resources to the State of Montana to assist in fire suppression.”

Bullock has also deployed the Montana National Guard to assists in the emergency.

The fires include the following+

The Moose Meadows Fire (southwest of Philipsburg): 900ha  (~ 2,200 acres)
The Firestone Flats Fire (ENE of Arlee)+ 700ha
Gold Pan Fire Complex (SW of Sula on the Montana-Idaho border): 5,600ha
The Red Shale Fire (Bob Marshall Wilderness): 3,200ha

More information is listed at http://inciweb.nwcg.gov/state/27/0/

Meanwhile, residents of Greer, Idaho, are on standby to evacuate, said the sheriff’s office.

Hundreds of wildfires, mostly sparked by lightning storms, are currently burning hundreds of thousands of hectares (acres) across the Western United States, Alaska, and Hawaii.

Related Links

• Fierce Wildfires Destroy Dozens of Idaho Homes August 16, 2015