— Details on the EPA plan; agency hid proposed increases to “avoid confusion”; PAG levels 100s-1000s times Clean Drinking Water standards

From Public Employees for Environmental Responsibility

For Immediate Release: Dec 22, 2016
Contact: Kirsten Stade (202) 265-7337

RADICAL DRINKING WATER RADIATION RISE CONFIRMED IN EPA PLAN

EPA Hid Planned Exposure Levels 1,000s of Times Safe Drinking Water Act Limits


Washington, DC — In the last days of the Obama Administration, the U.S. Environmental Protection Agency is about to dramatically increase allowable public exposure to radioactivity to levels thousands of times above the maximum limits of the Safe Drinking Water Act, according to documents the agency surrendered in a federal lawsuit brought by Public Employees for Environmental Responsibility (PEER). These radical rollbacks cover the “intermediate period” following a radiation release and could last for up to several years. This plan is in its final stage of approval.

The documents indicate that the plan’s rationale is rooted in public relations, not public health. Following Japan’s Fukushima meltdown in 2011, EPA’s claims that no radioactivity could reach the U.S. at levels of concern were contradicted by its own rainwater measurements showing contamination from Fukushima throughout the U.S. well above Safe Drinking Water Act limits. In reaction, EPA prepared new limits 1000s of times higher than even the Fukushima rainwater because “EPA experienced major difficulties conveying to the public that the detected levels…were not of immediate concern for public health.”

When EPA published for public comment the proposed “Protective Action Guides,” it hid proposed new concentrations for all but four of the 110 radionuclides covered, and refused to reveal how much they were above Safe Drinking Water Act limits. It took a lawsuit to get EPA to release documents showing that –

  • The proposed PAGs for two radionuclides (Cobalt-60 and Calcium-45) are more than 10,000 times Safe Drinking Water Act limits. Others are hundreds or thousands of times higher;
  • According to EPA’s own internal analysis, some concentrations are high enough to deliver a lifetime permissible dose in a single day. Scores of other radionuclides would be allowed at levels that would produce a lifetime dose in a week or a month;
  • The levels proposed by the Obama EPA are higher than what the Bush EPA tried to adopt–also in its final days. That plan was ultimately withdrawn; and
  • EPA hid the proposed increases from the public so as to “avoid confusion,” intending to release the higher concentrations only after the proposal was adopted. The documents also reveal that EPA’s radiation division even hid the new concentrations from other divisions of EPA that were critical of the proposal, requiring repeated efforts to get them to even be disclosed internally.

“To cover its embarrassment after being caught dissembling about Fukushima fallout on American soil, EPA is pursuing a justification for assuming a radioactive fetal position even in cases of ultra-high contamination,” stated PEER Executive Director Jeff Ruch, noting that New York Attorney General Eric Schneiderman has called for the PAGs to be withdrawn on both public health and legal grounds. “The Safe Drinking Water Act is a federal law; it cannot be nullified or neutered by regulatory ‘guidance.’”

Despite claims of transparency, EPA solicited public comment on its plan even as it hid the bulk of the plan’s effects. Nonetheless, more than 60,000 people filed comments in opposition.

“The Dr. Strangelove wing of EPA does not want this information shared with many of its own experts, let alone the public,” added Ruch, noting that PEER had to file a Freedom of Information Act lawsuit to force release of exposure limits. “This is a matter of public health that should be promulgated in broad daylight rather than slimed through in the witching hours of a departing administration.”

###

 

View ultra-high proposed PAG allowable concentrations

(and explanation for the chart)

See briefing memo explaining why EPA wants water PAGs

Read letter of opposition from New York Attorney General

Revisit PEER lawsuit

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— Obama administration final gift: EPA adopts huge increase in allowable drinking water contamination

From Public Employees for Environmental Responsibility

For Immediate Release: Jan 19, 2017
Contact: Kirsten Stade (202) 265-7337

FIG LEAVES NO COVER FOR DRINKING WATER RADIATION ROLLBACK

Final Approval for Radical Radiation Rise in Water Supplies after Nuclear Release


Washington, DC — In a not so lovely parting gift, the Obama administration today formally adopted a policy of allowing public exposure to radioactivity following a nuclear release at levels many times the maximum limits of the Safe Drinking Water Act. Last-minute modifications ladled in by the U.S. Environmental Protection Agency (EPA) to address public health concerns afford scant comfort, according to Public Employees for Environmental Responsibility (PEER).

The “Protective Action Guide (PAG) for Drinking Water after a Radiological Incident” was finalized today by its publication in the Federal Register. This policy lets the public consume water containing radiation at levels hundreds and thousands of times what is permitted for the more than 100 chemical elements that can emit radiation (radionuclides) under the Safe Drinking Water Act.

“Since this policy authorizes leaving people in contaminated zones and not providing them bottled or other potable drinking water for long periods, it should be called a ‘Protective Inaction Guide,’” stated Jeff Ruch, Executive Director of PEER which had to sue EPA to force release of information specifying what levels of which radionuclides EPA would permit public exposure to. “Under this policy, affected Americans would be guinea pigs in an untimed radiation experiment.”

In its final action, the EPA claims to have tightened the policy with respect to duration of public exposure, the nature of the triggering event and protections for infants and nursing mothers. PEER disputes the accuracy and efficacy of these supposed mitigations for the following reasons:

  • Duration. These rollbacks cover the “intermediate period” after the radiation release has been brought under control (not necessarily stopped but no longer growing). EPA now contends that this period may last for “week to months but not longer than a year.” However, the PAG itself states that the early, intermediate and late “phases cannot be represented by precise periods of time” and suggests their duration be viewed as “in terms of activities, rather than time spans.” Nor does EPA specify what happens if this intermediate period extends beyond a year;
  • Trigger. EPA now says application of the PAG is limited to “nationally significant radiological contamination incidents” but does not define the term. The PAG itself states that it covers “a wide range of incidents,” not just reactor accidents but also spills. By contrast, the EPA website FAQ posting says the PAG applies in “any radiological emergency”; and
  • Sensitive Populations. The PAG allows 500 millirems (mrem) of radiation exposure for the general population but only 100 mrem for the most sensitive populations (e.g., infants, children, pregnant women and nursing women). But EPA never explains how non-nursing children will get only one-fifth the radiation their parents receive in situations lacking clean drinking water.

“EPA’s qualifications tacitly concede the dangers to public health but do little to solve them,” added Ruch, noting that PEER is considering a lawsuit to nullify the PAG. “Among other legal vulnerabilities, this policy flies in the face of the anti-backsliding requirements of the Safe Drinking Water Act.”

###

View the Federal Register notice

Examine redline showing recent EPA rewrites

See EPA’s public relations motivation for the PAG

Look at the full Drinking Water PAG

Read the non-explanatory EPA blog posting

http://www.peer.org/news/news-releases/fig-leaves-no-cover-for-drinking-water-radiation-rollback.html

— Tell EPA — Stop dangerous radioactive drinking water

From the Nuclear Information and Research Service

November 21, 2016

In July, thousands of us took action to stop dangerous new radiation guidance for drinking water. The EPA refused to listen, and now this guidance could be approved anytime–unless we act now!

Environmental Protection Agency (EPA) Administrator Gina McCarthy is on the verge of approving radiation levels hundreds and thousands of times higher than currently allowed in drinking water and at cleaned-up Superfund sites. These mis-named “Protective” Action Guides for Drinking Water (Water PAGs)  dramatically INCREASE allowable radioactivity in water. Enormous levels of invisible but deadly radioactive contamination would be permitted in drinking water for weeks, months or even years after a nuclear accident or “incident.” The PAGs are not for the immediate phase after a radioactive release but the next phase–which could last for years–when local residents may return home to contaminated water and not know the danger.

Take action now: Protect drinking water from dangerous radiation levels!

There are two quick actions to take today:

  1. Tell your EPA Regional Administrator (see map and list below) to ask EPA Administrator Gina McCarthy why she is raising radiation levels allowed in drinking water.
  2. Send a message to Administrator McCarthy yourself asking her not to approve these dangerous radiation levels in drinking water.

We have stopped PAGs like these from being approved before–and we can do it again. EPA insiders attempted to push these dangerous guides through in the waning days of the Bush administration, and public pressure like this got the agency to pull them back. Now we have to do it again!

Click here to take action now.

Thanks for all you do!

Diane D’Arrigo
Radioactive Waste Project Director

More Information

The PAGs protect the polluters from liability, not the public from radiation. CHECK out this NBC4 News Story.

These PAGs are a bad legacy. Approving them now is a deceptive way to circumvent the Safe Drinking Water Act, Superfund cleanup levels, and EPA’s history of limiting the allowable risk of cancer to 1 in a million people exposed (or at most 1 in 10,000 in worst-case scenarios).

The PAGs don’t just affect water!

  • They markedly relax long-term cleanup standards.
  • They set very high and outdated radiation levels allowable in food.
  • They eliminate requirements to evacuate people vulnterable to high radiation doses to the thyroid and skin.
  • They eliminate limits on lifetime whole body radiation exposures.
  • And they recommend dumping radioactive waste in municipal garbage dumps not designed for such waste.

Outrageously, EPA is expanding the kinds of radioactive ‘incidents’ that would be allowed to give off these dangerously high levels and doses. PAGs originally applied to huge nuclear disasters like the nuclear power meltdowns at Fukushima or a dirty bomb BUT NOW they could ALSO apply to less dramatic releases from nuclear power reactors or radio-pharmaceutical spills, nuclear transport accidents, fires or any radioactive “incident” that “warrant[s] consideration of protective action.”

EPA REGIONS and REGIONAL ADMINISTRATORS

Region 1 Administrator Curt Spalding
(617) 918-1010
spalding.curt@epa.gov;

Region 2 Administrator Judith Enck
(212) 637-5000
enck.judith@epa.gov

Region 3 Administrator Cecil Rodrigues
(215) 814-2683
Rodrigues.cecil@Epa.gov

Region 4 Administrator Heather McTeer Toney
(404) 562-9900
McTeertoney.heather@Epa.gov

Region 5 Acting Administrator Robert A. Kaplan
(312) 886-3000
Kaplan.robert@Epa.gov

Region 6 Administrator Ron Curry
(214) 665-2100
Curry.ron@Epa.gov

Region 7 Administrator Mark Hague
(913) 551-7006
Hague.mark@Epa.gov

Region 8 Administrator Shaun McGrath
(303) 312-6532
McGrath.shaun@Epa.gov

Region 9 Acting Administrator Alexis Strauss
(415) 947-8000
Strauss.alexis@Epa.gov

Region 10 Administrator Dennis McLerran
(206) 553-1234
mclerran.dennis@epa.gov

For more info, contact Diane D’Arrigo at NIRS: dianed@nirs.org or 301-270-6477

http://org2.salsalabs.com/o/5502/t/0/blastContent.jsp?email_blast_KEY=1378216

http://www.nirs.org

— EPA plans to vastly raise drinking water radioactivity limits; register for July 13 telebriefing “Dangerous Drinking Water”

From Nuclear Information and Resource Service

July 1, 2016

Dear Friends,

The U.S. Environmental Protection Agency (EPA) has quietly proposed to raise the allowable levels of radioactivity in drinking water a nuclear incident to hundreds of times their current limits. If this guidance goes through, EPA’s action will allow people to drink water with concentrations of radioactivity at vastly higher levels.

Look no further than the current water crisis in Flint, Michigan to understand concern that the EPA will not act to protect public health in an emergency. In this case, the EPA is attempting to ensure that it would not have to act decisively to protect public health!

But there is still time to act.

Call in to the July 13 telebriefing to find out more.
http://org2.salsalabs.com/o/5502/p/salsa/event/common/public/?event_KEY=81984

You are invited to join us on WEDNESDAY JULY 13 for a national telebriefing: Dangerous Drinking Water, with presentations by leading experts and activists:
•Diane D’Arrigo, Radioactive Waste Project Director, Nuclear Information and Resource Service
•Daniel Hirsch, Director, Program on Environmental and Nuclear Policy, University of California Santa Cruz
•Emily Wurth, Water Program Director, Food and Water Watch

•Moderated by NIRS Executive Director, Tim Judson

The open and free event will be on the phone, starting at 8 pm eastern, 7 pm central, 6 pm mountain and 5 pm pacific. We will reserve the second half of the program for questions and discussion.

Register to attend the July 13 telebriefing.
http://org2.salsalabs.com/o/5502/p/salsa/event/common/public/?event_KEY=81984

The program will focus on EPA Guidance that massively increases the permitted levels of radioactivity in drinking water for years after any nuclear incident that requires consideration of “protective action,” ranging from a spill, leak or transport accident to a dirty bomb or nuclear meltdown—a nuclear accident of any kind, big or small. Allowable concentrations of radioactive elements allowed to come out of your tap would rise hundreds or even thousands of times above the current Maximum Concentration Levels allowed under the Safe Drinking Water Act regulations. Click here to review EPA’s proposal.
https://www.epa.gov/radiation/protective-action-guides-pags

Nuclear Energy is Dirty in many dimensions, but first, and foremost because of its dangerous ionizing radiation. The EPA guidance, allowing us to drink highly radioactive water is a clever effort to bypass existing limits, which the law prevents from being weakened. It is yet another way to shift liability and cleanup costs to the public from industry and government in case of a “nuclear event.” For instance, for most radionuclides the Safe Drinking Water levels are based on no more than 4 millirems a year exposure from drinking water; the proposed water PAGs would allow 500 millirems a year with no notice, and no action to limit exposure to adults. This difference protects the government and industry from any liability from massively increased health consequences.

Although EPA for the first time ever admits that those under 15 years of age are at greater risk than adults the draft PAG only pays lip-service to considering a lower level which is still enormously higher than current water limits. This is in addition to rest of EPA PAGs, which allow even more exposure from air and food.

Call in to learn more about this federal guidance and how to help stop it.
http://org2.salsalabs.com/o/5502/p/salsa/event/common/public/?event_KEY=81984

Thanks for all you do,

Mary Olson, Southeast Office Director

Stay Informed:

NIRS on the web: http://www.nirs.org

http://org2.salsalabs.com/o/5502/t/0/blastContent.jsp?email_blast_KEY=1367594

— Fukushima city government donated 10,000 bottles of their tap water to Kumamoto city

From Fukushima Diary

On 4/18/2016, Fukushima city Waterworks Bureau donated 10,000 bottles of their tap water to Kumamoto city.

Kumamoto city is one of the main disaster areas of 2016 Kumamoto earthquakes.

Fukushima tap water is named “Fukushima water” by the city government and obtained “Monde Selection” in 2015 and 2016 for its taste.

056

https://www.city.fukushima.fukushima.jp/suidou/?p=15191

https://www.city.fukushima.fukushima.jp/suidou/?p=7982

http://fukushima-diary.com/2016/04/fukushima-city-government-donated-10000-bottles-of-tap-water-to-kumamoto-city/

Nevada’s atomic test legacy: underground aquifers are radioactive

…polluted 1.6 trillion gallons of water…About a third of the [underground atomic] tests were conducted directly in aquifers…

Federal drinking water standards in 2009 when this article was written

..For alpha particles, the standard is 15 picocuries per liter; for long-term radionuclides, it’s 50 picocuries per liter

radioactivity in the water reaches millions of picocuries per liter.

From Los Angeles Times

Nevada’s hidden ocean of radiation

by Ralph Vartabedian
November 13, 2009

YUCCA FLAT, NEV. — A sea of ancient water tainted by the Cold War is creeping deep under the volcanic peaks, dry lake beds and pinyon pine forests covering a vast tract of Nevada.

Over 41 years, the federal government detonated 921 nuclear warheads underground at the Nevada Test Site, 75 miles northeast of Las Vegas. Each explosion deposited a toxic load of radioactivity into the ground and, in some cases, directly into aquifers.

When testing ended in 1992, the Energy Department estimated that more than 300 million curies of radiation had been left behind, making the site one of the most radioactively contaminated places in the nation.

During the era of weapons testing, Nevada embraced its role almost like a patriotic duty. There seemed to be no better use for an empty desert. But today, as Nevada faces a water crisis and a population boom, state officials are taking a new measure of the damage.

——————————

For The Record
Los Angeles Times Wednesday, November 18, 2009 Correction
Nevada radiation: An article in Friday’s Section A about contaminated water at the Nevada Test Site said the federal drinking water standard for radiation is 20 picocuries per liter. There are actually three standards, depending on the type of radiation: For alpha particles, the standard is 15 picocuries per liter; for long-term radionuclides, it’s 50 picocuries per liter; and for short-lived tritium, it’s 20,000 picocuries per liter. The article also said the test site is northeast of Las Vegas; it is northwest.

—————————-

They have successfully pressured federal officials for a fresh environmental assessment of the 1,375-square-mile test site, a step toward a potential demand for monetary compensation, replacement of the lost water or a massive cleanup.

“It is one of the largest resource losses in the country,” said Thomas S. Buqo, a Nevada hydrogeologist. “Nobody thought to say, ‘You are destroying a natural resource.’ “

In a study for Nye County, where the nuclear test site lies, Buqo estimated that the underground tests polluted 1.6 trillion gallons of water. That is as much water as Nevada is allowed to withdraw from the Colorado River in 16 years — enough to fill a lake 300 miles long, a mile wide and 25 feet deep.

At today’s prices, that water would be worth as much as $48 billion if it had not been fouled, Buqo said.

Although the contaminated water is migrating southwest from the high ground of the test site, the Energy Department has no cleanup plans, saying it would be impossible to remove the radioactivity. Instead, its emphasis is on monitoring.

Federal scientists say the tainted water is moving so slowly — 3 inches to 18 feet a year — that it will not reach the nearest community, Beatty, about 22 miles away, for at least 6,000 years.

Still, Nevada officials reject the idea that a massive part of their state will be a permanent environmental sacrifice zone.

Access to more water could stoke an economic boom in the area, local officials say. More than a dozen companies want to build solar electric generation plants, but the county cannot allow the projects to go forward without more water, said Gary Hollis, a Nye County commissioner.

The problem extends beyond the contamination zone. If too much clean water is pumped out of the ground from adjacent areas, it could accelerate the movement of tainted water. When Nye County applied for permits in recent years to pump clean water near the western boundary of the test site, the state engineer denied the application based on protests by the Energy Department.

(The department did not cite environmental concerns, perhaps to avoid acknowledging the extent of the Cold War contamination. Instead, federal officials said the pumping could compromise security at the test site, which is still in use.)

“Those waters have been degraded,” said Republican state Assemblyman Edwin Goedhart of Nye County, who runs a dairy with 18,000 head of livestock. “That water belongs to the people of Nevada. Even before any contamination comes off the test site, I look at this as a matter of social economic justice.”

Continue reading

Study overview – Tracking the Fallout and Fate of Fukushima Iodine-129 in Rain and Groundwater

He minimizes the impacts of the fallout, but the charts are telling and contradict some of his statements. This is increased and increasing exposure of a near-permanent element that is toxic. It is getting into aquifers and drinking water rapidly. Plus it is only one radioisotope. How many hundreds more accompanied iodine-129, and into the groundwater as well? What is the total rad amount that we are drinking and breathing?

Posted by Matt Herod, co-author of University Ottawa study

The atmospheric transport of iodine-129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

December 21, 2015

A recently published paper (by myself and colleagues from uOttawa and Environment Canada) investigates the environmental fate of the long lived radioisotope of iodine, 129I, which was released by the Fukushima-Daichii Nuclear Accident (FDNA). Within 6 days of the FDNA 129I concentrations in Vancouver precipitation increased 5-15 times above pre-Fukushima concentrations and then rapidly returned to background. The concentrations of 129I reached were never remotely close to being dangerous, however they were sufficient to distinguish the impact of the FDNA on the region.

Subsequent sampling of groundwater revealed slight increases in 129I concentration that were coincident with the expected recharge times. This suggests that a small fraction of the FDNA-derived 129I may have been transported into local groundwater after infiltrating through soils.

Iodine129_Precip_Sample_BC_JP

Sample map showing location of all three precipitation sampling locations as well as the location of both wells used for groundwater sampling. The surface expression of the Abbotsford-Sumas Aquifer is shaded.

What is iodine-129 and where does it come from?

Iodine-129 is the longest lived isotope of iodine with a half-life of 15.7 million years. It is radioactive and occurs everywhere throughout the environment. It is produced in three ways. The first two are natural and the third is by the nuclear industry.

The natural production of 129I occurs in the atmosphere and in soil/rocks. The atmospheric production happens when a cosmic ray proton hits a xenon-129 nucleus and removes a neutron, replacing it and creating an iodine-129 nucleus. The production in soil and rocks happens when a uranium-238 nucleus spontaneously fissions and one of the halves it releases has a mass of 129 ala, iodine-129.

The anthropogenic production occurs because when uranium fissions in a nuclear reactor sometimes one of the parts is 129I. This anthropogenic production is by far the largest source in the environment as substantial amounts have been released by nuclear fuel reprocessing. This 129I that has been released can trace a host of environmental processes and inform us about what happens to 129I or the much more dangerous, 131I. The current levels of 129I are much too low to pose a health threat to humans or the environment, but do allow 129I to be used as an environmental tracer.

129I from Fukushima is present in Vancouver, B.C. rain

The purpose of this research was to discover the fate of 129I in the released by Fukushima, which although a small amount, was isolated in time and space. We measured the 129I deposition in rain and its subsequent movement though soils and see if it reached groundwater. The results tell us about the impact of Fukushima, how 129I moves, where it is attenuated, and how quickly contaminants in this aquifer move from the ground surface to the water table. This knowledge can then be applied to understand 129I behavior in other settings such as nuclear waste repositories and watersheds or it can be used to learn about the behavior of other types of contaminant in this aquifer and how vulnerable it is to contamination.

The results in rain show an increase in 129I concentrations of up to 220 million atoms/L*. This increase was seen ~6-10 days after the emission from Fukushima began and are 5-15 times higher than rain samples collected before Fukushima. Following this increase 129I concentrations returned to background with a few weeks. This agrees with other studies monitoring the fallout of Fukushima derived radioisotopes [Wetherbee et al., 2012]. Furthermore, atmospheric back trajectory modelling shows trajectories for air parcels arriving in Vancouver from over the Pacific ocean and Japan.

Figure2_129IPrecip

[Editor: Note that 129I is still spiking in February 2012, (top chart) and could be trending toward another spike, when the data stops]

Variation in the concentration of 129I and the 129I/127I ratio in precipitation from Vancouver, Saturna Island and NADP site WA19 over time. The time range that each NADP sample integrates is displayed using horizontal error bars. 1σ error is contained within data points if not visible. The dashed vertical line shows the date of the FDNA relative to samples.

We also calculated the mass flux of 129I from Fukushima. That is the actual quantity of 129I that was deposited on the region in grams, or in this case in atoms/m2. This was calculated by simply multiplying the concentration of 129I in rain by the amount of rain that fell. We found that only about 15% of the annual 129I deposition in the Vancouver region could be directly linked to Fukushima affected rain events. The total mass deposited by Fukushima was ~0.0000000000002 (2 x 10^-13) grams. This is a negligibly small quantity with respect to radioactive risk.

Despite the fact that the deposition of 129I from Fukushima was infinitesimally small it was still measurable. Therefore, the question became where did it go and can we learn about local groundwater resources using 129I as a tracer?

129I variation in groundwater may be due to Fukushima

The results in groundwater show very small 129I concentration increases. Two different wells were sampled. The first had a recharge time, which is the time it takes for water to move from the water table to the well screen, where it is sampled, of 0.9 years and the second had a recharge time of 1.2 years [Wassenaar et al., 2006]. The exact time it takes for water and dissolved contaminants to travel through the unsaturated zone was unknown. However, the sediments of this aquifer are very coarse and are known for their ability to rapidly transport contaminants, such as nitrate [Chesnaux and Allen, 2007]. Therefore, if we were going to see 129I from Fukushima this was an ideal location.

The increases in groundwater 129I concentrations were seen in two different wells (ABB03 and PB20) located close to one another. The two wells also had slightly different recharge times. The first was 0.9 years and the second was 1.2 years. The 129I anomaly in the first well occurred at 0.9 years and in the second well at 1.2 years. These 129I anomalies, which occurred exactly when the recharge age predicted they would, suggests that some of the 129I deposited by Fukushima was reaching the wells and causing these increases.

Gwater_129Iconc

Temporal variation in the concentration of 129I in groundwater in ABB03 and PB20. The solid vertical line shows the date of the Fukushima accident and the dashed horizontal line shows the median of each dataset respectively. The 3H/3He ages from [Wassenaar et al., 2006] of groundwater in each well and their uncertainty is pictured as the solid arrow which is aligned with the 129I anomaly possibly caused by the FDNA. The dashed arrow covers a 40 day (0.11 year) time span and represents a possible vadose zone transport time.

In order to verify if it was possible for 129I to travel from the ground surface to the water table in the time required to produce the variations observed we modelled its transport time and attenuation through the unsaturated zone.

The time it took for 129I to reach the water table in the model was then added to the previously dated recharge time to get an estimate for how long it might take 129I from Fukushima to reach the wells we sampled. The results show that it is indeed possible for 129I deposited in rain to infiltrate through the unsaturated zone and reach the wells in time for us to detect it. However, this rapid transport assumes that certain flow paths exist to rapidly conduct 129I due to the heterogeneous lithology of the unsaturated zone. There is evidence of such flow paths [McArthur et al., 2010].

To summarize,

  • Within a week of the FDNPP accident elevated 129I concentrations were observed in precipitation. This agrees very well with work on other radionuclides in air filters and rain.
  • 129I concentrations in rain returned to background within a few weeks. However, discrete pulses of elevated 129I occurred for another several months.
  • Elevated 129I concentrations were measured in two wells and corresponded with the expected recharge times indicating that 129I from Fukushima can be traced into groundwater.
  • Vadose zone modeling has shown that 129I can be rapidly transported to the water table and reach the well screen in accordance with groundwater ages.
  • We propose 129I transport is enhanced by preferential dispersion of 129I that exists due to the heterogeneous nature of the vadose zone.
  • This results in variability in groundwater 129I concentrations that preserve the variability in the input of 129I via washout with some dampening of the signal due to attenuation and dilution.

Fukushima Model

Conceptual model showing the possible transport pathways of Fukushima derived 129I which was deposited via precipitation. A fraction of this 129I was rapidly transported through a heterogeneous vadose zone via preferential flowpaths to groundwater where minor 129I variation was detected. The remainder was retarded or attenuated in the vadose zone during transport.

Thanks for reading, if you have any questions or concerns please leave a comment or send me an email to discuss further!

*Note: 100 million atoms/L of 129I is equivalent to an activity of 0.00000014 (1.4 x 10^-7) Bq/L. These quantities are extremely low level and only the most sensitive analytical methods in the world can detect them. This amount of radioactivity is several orders of magnitude lower than the natural background radiation produced by naturally occurring radionuclides in soil and the atmosphere. For more on naturally occurring radioactivity see here. Even a clean rainfall has about 1 Bq/L of tritium (radioactive hydrogen), which remains from atmospheric weapons testing in the 1960’s

Access the full paper here: http://onlinelibrary.wiley.com/doi/10.1002/2015WR017325/abstract

References

Chesnaux, R., and D. M. Allen (2007), Simulating Nitrate Leaching Profiles in a Highly Permeable Vadose Zone, Environ. Model. Assess., 13(4), 527–539, doi:10.1007/s10666-007-9116-4.

McArthur, S. A. Q., D. M. Allen, and R. D. Luzitano (2010), Resolving scales of aquifer heterogeneity using ground penetrating radar and borehole geophysical logging, Environ. Earth Sci., 63(3), 581–593, doi:10.1007/s12665-010-0726-9.

Wassenaar, L. I., M. J. Hendry, and N. Harrington (2006), Decadal geochemical and isotopic trends for nitrate in a transboundary aquifer and implications for agricultural beneficial management practices., Environ. Sci. Technol., 40(15), 4626–32.

Wetherbee, G. A., D. A. Gay, T. M. Debey, C. M. B. Lehmann, and M. A. Nilles (2012), Wet Deposition of Fission-Product Isotopes to North America from the Fukushima Dai-ichi Incident, March 2011, Environ. Sci. Technol., 46(5), 2574–2582.

By

Matt Herod is a Ph.D Candidate in the Department of Earth Sciences at the University of Ottawa in Ontario, Canada. His research focuses on the geochemistry of iodine and the radioactive isotope iodine-129. His work involves characterizing the cycle and sources of 129I in the Canadian Arctic and applying this to long term radioactive waste disposal and the effect of Fukushima fallout. His project includes field work and lab work at the André E. Lalonde 3MV AMS Laboratory. Matt blogs about any topic in geology that interests him, and attempts to make these topics understandable to everyone. Tweets as @GeoHerod.

Tracking the Fallout and Fate of Fukushima Iodine-129 in Rain and Groundwater

Posted under Fair Use Rules.