| August 21, 2012 | 0 Comments More

Editor’s Note: Following is Part One of a final article on the Homestake Mill Cleanup. Part Two, Murray Acres, Pathways for Pollution, and Health, will publish next Tuesday, Aug. 28.

Part One:

Environmental Cleanup

The Legacy: The mining and processing of uranium ore in the Grants-Milan uranium belt left large swathes of contamination and thousands of sick workers and family members exposed to uranium in some form.

EPA Region 6 stated that 97 mines are considered potentially hazardous legacy mines, and four out of five of the legacy-contaminated millsites are in the Ambrosia Lake district north of Milan. The Jackpile mine/mill in Laguna Pueblo is the fifth.

The controversy about cleanup (remediation) of the Barrick Gold-owned Homestake mill and the experience of residents in nearby Murray Acres and neighboring subdivisions who have battled for the remediation could become a microcosm of the issues that face other residents elsewhere in the Milan-Grants area from both an environmental and health perspective. This is true no matter what your stance is on uranium mining.

This article looks at air and water controversies between cleanup advocates, largely neighbors, and government regulators and the company.

The second article will look at some area health issues. In the past, many people living in the Murray Acres subdivision were exposed to uranium, not just from their neighbor Homestake, but through uranium’s byproducts in mines, mills, sometimes at home by virtue of where they lived, where they worked, or whether a worker brought home laundry. Today, they live with differing degrees of water and air contamination and share poor health, or have love ones who are now deceased.

The above list may look familiar to other Grants’ residents and bring home how complex addressing the health legacy of uranium is.

Murray Acres’ residents, many of whom are members of the Bluewater Valley Downstream Alliance (BVDA), feel strongly that they have little support from their neighbors in the Grants’ area.

Ironically, they believe that it is those who never worked within the uranium industry who care the least about those whose health and environment was affected by it. Most, but not all BVDAers, were part of the industry. They worked as everything from a corporate manager of Kerr McGee in New Mexico, to a manual laborer who worked at the Homestake tailings.

Murray Acres subdivision structures range from split-level homes to manufactured housing, which are located about four miles north of Milan.

Some residents to the east appear to be less than 1,000 feet from mill tailings bordering the Homestake minesite and on the south about 2,500 feet. The first residents living in the area moved there in the 1940s. The Homestake Mill began operating in 1958, and subsequently more people moved into the area.

Nobody contests some basic facts: The mill operated from 1958-1990 as Homestake passed through several partnerships and owners before becoming a part of Barrick Gold in 2001. Pollution was first detected in groundwater in 1961.

The site was designated as a federal Superfund site in 1982 with a formal decision in 1983 and with Nuclear Regulatory Commission (NRC) named lead agency in 1993.

Residents sued Homestake in 1983 claiming alluvial (shallow) water contamination, and in 1985, Homestake agreed to hook up residents to the Milan municipal water with 10 years of free service. The mill was decommissioned by 1995 leaving two tailings piles behind, one 200 acres and one 40 acres with 22-23 million tons of tailings.

According to EPA: Principal contaminants of concern in groundwater at the site are uranium, selenium, radium-226 + radium-228, thorium-230, chromium, molybdenum, vanadium, sulfate, chloride, nitrate, and total dissolved solids (TDS).

Radium-226, which releases radon gas into air, was the primary contaminant of concern present in the soil.

During the past 35 years, more than 600 wells have been installed for groundwater injection collection and monitoring of five aquifers beneath the site. The aquifers are now known to mix with each other.

BVDA has said that Homestake verbally promised cleanup by 1992-95. That date has been sliding ever since to 2012, then 2017—and in June that date was moved to 2022.

Once the site is declared cleaned up or “remediated” by NRC it will be turned over to the Department of Energy to oversee in perpetuity.

Within these five aquifers, there is pollution moving from north in the Bluewater Valley to the south from other mills and mines. This “plume” of contaminated groundwater now passes through the Homestake location that contributed millions of gallons of pollution to the site. Exactly where the larger plume lies, regulators do not appear to be able to say, because they say they are concerned with the site rather than what lies downstream. They do say that the Homestake plume moves to the southwest and southeast.

The mill was originally approved by the Atomic Energy Commision (AEC) to produce concentrated uranium yellow cake that the government would purchase for nuclear weapons.

By 1971, the U.S. government was out of the nuclear business, and private industry took responsibility for production, environmental and occupational health protection.

The NRC succeeded the AEC.

NRC has a Memorandum of Understanding with U.S. Environmental Protection Agency and the New Mexico Environmental Division (NMED) to regulate environmental impacts jointly, but NRC makes the ultimate decisions for the site.

The NRC’s facility evaluator, Steve Cohen, discussed a major factor exacerbating pollution from Homestake and older “legacy” uranium mills.

“In 1958, prior to modern standards, some mill sites and tailings’ impoundments were constructed intentionally on permeable rock and soils. They actually managed fluids discharged from tailings by deliberately releasing them into groundwater. By the time standards and laws passed in 1978, and EPA regs, were implemented in the early 80s, these impoundments had been infiltrating pollution to groundwater for quite a long time,” he explained.

Other facts are less clear and interpreted differently by regulators and frustrated Homestake neighbors and activists.

Johnnie Head of BVDA recently wrote Beacon Editor Donald Jaramillo, “Barrick-Homestake said they’ve spent $100 million on remediating the site, which is eight days of Barrick’s 2011 net profit.”

Homestake-Barrick Project Manager Al Cox said that the most recent estimate given to NRC is that it would cost $80 million-plus to complete the closure.

Residents say the job must be done better, particularly since taxpayers pay one-half the money for the cleanup of the site. Cynicism is directed toward Homestake; but the frustration seems to be with the regulators, and this article looks primarily at their perspectives.

Even Cox told the Beacon, “The regulatory process is a bit frustrating, especially when we are dealing with several regulatory agencies, state and federal.”

Community members and governmental entities disagree widely on the pre-Homestake degree of air and water contamination, especially water. Were pre-mill air and water pollution levels clean or at least moderately clean prior to tailings’ dust blowing into houses and tailings’ discharges contaminating groundwater?

A second question: Were the mill tailings breached multiple times by floods sending radioactive tailings’ contaminated water into the yards and houses of residents as they allege?

A third very long-term question is how much other uranium facilities upstream of Homestake are now contaminating the water? This is generally accepted as true by all parties to some degree but not considered justification by neighbors to not remediate groundwater more.

A related fourth question: Will pollution from the Bluewater Valley funneling through the Murray Acres region move south toward Milan and other areas downstream? Is the BVDA simply a first group of affected residents, contaminated decades earlier than others?

A last question, that has received relatively little attention, is whether the Federal National Environmental Policy Act (NEPA) should be applied in order to deepen the overall public participation and technical input.

Water: Groundwater Was Clean, vs. We Don’t Know and It Isn’t Relevant

Two practical goals guide Homestake cleanup: Onsite, how much do contamination levels within the tailings need to be reduced to not discharge into groundwater? Second, what is the groundwater quality to be at the perimeter of the site to prevent pollution from traveling off of it?

The residents of Murray Acres are interested in restoring their water quality to either federal potable water standards (MCLs) or to what they say were background water levels before Homestake’s mill existed.

BVDA members don’t contest that contamination is moving into the area from the north of the mill, where other mills and mines polluted the aquifer. They question how well it has been characterized and argue that no coherent case has been made that natural uranium or metals have been a source of contamination.

Milton and Johnnie Head were among the founders of BVDA, and they, along with daughter Candace Head Dylla and her husband, Steve Dylla, remain core members.

Milton Head gathered records from state agencies sampled in the 1950s. The data indicated that a variety of water constituents were present in some wells and not others.

Head Dylla commented, “Members of our community were here by the 1940s. The contamination was found in 1961. By 1988-89, (when selenium and uranium standards were first established to be cleaned up from the alluvial aquifer at the Homestake site) the sampling would clearly have been of contaminated water.”

Those cleanup standards were subsequently weakened in 2006 when all three regulators accepted Homestake’s 2001 study that they shouldn’t have to clean up beyond a contamination level that their consultants determined was north of the site in 1999.

Current “background” cleanup standards for various aquifers are as much as six times weaker than MCL drinking water standards. Earlier standards for the alluvial aquifer were about one-third to one-half as stringent.

The weaker 2006 standards are for four lenses of groundwater beneath Homestake: the mixing zone, the upper Chinle, middle Chinle, lower Chinle. Beneath them lies the deeper San Andres aquifer. The Chinle and alluvial lenses of water actually make contact with each other under various parts of the Homestake site. Some parts naturally mix because of bedrock pushing the different aquifers into each other or because of fractures in the rock that allow the different zones to mix.

“We can prove we had good water in terms of the elements tested in those days. We have sample data from the 50s. We will accept current drinking water standards for the other elements. NRC should have data from the original wells drilled during startup. Where is that data? Still no answers, other than ‘we’ve asked Barrick to try to find that data,’” said Head Dylla.

Milton Head compiled a synopsis of pre-1957 sampling that had been done by the State of New Mexico that he argued should serve as the basis for setting background standards. The data covered 1929-55 and included wells in San Rafael to the south of Milan as well as eight wells from differing aquifers north and “near” the Homestake site.

Some analyses had “total dissolved solids” (TDS) or mineralized calcium compounds that were higher than EPA’s current “secondary” non-health standards. Most wells had levels of sulfates that were either a little higher or lower than current standards. TDS and sulfates above these levels can cause stomach and intestinal problems particularly among infants and elderly. Some of the wells also had nitrate standards well above current health standards meant to prevent “blue baby syndrome” asphyxiation in infants. Uranium and selenium were not sampled in Head’s data.

Although historic data did not indicate pristine water quality, contaminant levels were well below those being utilized by regulators today as “alternative contamination” standards for Homestake.

NRC’s project officer, John Buckley, said that cleaner water in the past is not their issue, “I understand residents want their water back to a clean state — and they are correct regarding NRC’s perception. We are not even sure the water quality for that area was that good; it’s a uranium-rich area. If you assume the water generally moves north to south to the site, then you can make assumptions on where Homestake milling had an impact. Our answer to BVDA is, ‘We cannot use uncertain water quality data that appeared in groundwater southeast and southwest of Homestake to come up with background water quality values to the north.’”

Cutting to the chase, Buckley added, “It is not Homestake’s responsibility to clean more pollution than they contributed to the aquifer, and cleaning up the aquifer to a higher standard than we are shouldn’t be dealt with in this license.”

“It’s fair to say that area people will never be happy with these cleanup standards because the values contain contamination. The ‘alternate pollution levels’ we allow for certain contaminants present on-site are based on the premise that Homestake cleanup, which is working quite well, will halt any further substantial influence to drinking water sources off the site,” concluded Buckley.

Standards Based on Bad Science:

Dr. Rich Abitz is a geochemist, who has worked on major nuclear waste Superfund and other sites as a consultant and corporate scientist. In 2009, Abitz was hired with EPA funds to provide technical advice to BVDA on the December 2001 studies that established the high background contamination levels and current cleanup standards.

Abitz believes that the studies done for NRC by ERG, the Environmental Restoration Group, Inc. were extremely unscientific.

“Clarity is not a part of their documents, I’d grade them a failing three out of ten for that alone,” said Abitz.

Abitz continued, “How did ERG locate or choose wells as background? Don’t know. The sampling sites should have been random, but I don’t even know if they were existing wells. ERG claimed there was natural pollution, but they never used established scientific methods such as accurately defining the size of natural sources of pollution or the amount of rainfall that would have leached natural pollution into the San Mateo alluvial aquifer.

It seemed a bit like BS. Implementing background sampling scientifically is simply not that challenging. The laboratories that analyzed the split samples (one water quality sample sent to each lab) were very far apart on their results—like around 50 percent different. This is unacceptable for EPA when they regulate a Superfund site, but NRC allowed these results to get averaged, and the studies never bothered to explain why lab results might be so different.

It seems like there is a willful move by NRC to not gather the needed data. I can’t prove this; it’s speculation. This type of information is routine at Superfund sites all the time.”

Buckley responded, “We’ve had a number of discussions with Rich Abitz.”

NMED’s Permitting Officer Dave Mayerson readily admits that decision-making on Homestake remediation avoids the need for groundwater cleanup on a wider scale.

“Nobody thought to go out and sample water in the 50s and 60s explicitly to establish background levels, so we’ve had to choose wells for Homestake remediation. The process is somewhat controversial, and the science is not the best. NMED does no water quality monitoring to characterize the overall contamination plume in the area and compare it to drinking water standards. As one manager of regulation of Homestake, we can only require an individual site to cleanup.

This is a complicated mineralized basin, and there may have been some level of contamination that was always there. Way above the mines, it was probably pristine and may have picked up all these contaminants in the shallow alluvial basin where they then mixed with lower lenses of water.

We have a moving plume, there is no doubt about it, and it is moving south to an unknown point,” commented Mayerson.

Homestake Maps, sent by EPA Region 6 Project Remedial Manager Sairam Appaji, appear to show the plume for only about 5,000 feet south of the property boundary.

Appaji said, “The source of drinking water for the Village of Milan is from the deeper regional San Andres aquifer that has not been impacted. The village water wells are located approximately three-five miles south of the site and are not impacted”

However, it is unclear if the plume would affect shallower aquifers below Milan that are not the source of the town drinking water or whether it could get contaminated in the long term. A Mayerson 2008 study found at least one domestic well near Homestake that is above MCLs for uranium in the San Andres aquifer.

Mayerson added, “This may sound like a cop-out: I regulate a facility. I worked on Superfund sites for a while for NMED as a contractor to EPA, and I tried to promote a model where we look at a single site on a more regional basis. I am a supporter of taking of a more regional approach to understanding and regulating these aquifers—but I have not been successful in promoting that.”

“For better or worse, we make the operator responsible for the site only,” mused Mayerson,

“Domestic wells are contaminated: Many domestic wells sampled from 2005-7 by Mayerson within approximately one and one-half miles from the Homestake site had water quality that could cause health problems– particularly because some were still in domestic use.”

Mayerson’s July 2008 study showed that 45 out of 57 wells sampled violated one or more drinking water standards, and that all 14 residences that were not hooked up to Milan’s community water were among the 45. (See photomap)

Mayerson’s data showed that 19 wells exceeding MCLs for uranium were in the alluvial aquifer but six were in the middle Chinle and five in the lower Chinle aquifer. One was in the San Andres deep aquifer. (See Graph)

Cox said that Homestake, working with Mayerson, “agreed to pay for hookups to the municipal system for several specific residents. A number of those have already been completed, and Homestake hopes to complete the remaining four or five hookups in 2012.”

Appaji said, “EPA is currently working with other agencies on a plan to investigate potential upgradient sources identified in the Five Year Review, to prevent off-site plumes migrating to combine with the plume identified at the HMC Site if possible.”

Will Flushing Work?

The current approved plan of Homestake, which is being evaluated by the three agencies, is to flush relatively clean water through the tailings and then catch it and pump it to an evaporation pond until 2014 when it will be permanently capped and monitored for efficiency in maintaining cleaner groundwater.

BVDA opposes the current operation as totally unproven and unscientific.

Homestake injects ground water from the deep San Andres aquifer into the alluvial aquifer south of the most concentrated contaminant plumes. The injected groundwater raises groundwater around the point of injection, which then pushes the alluvial groundwater pollution northward rather than flowing south. Homestake has installed numerous points of injection to establish what the company calls a hydraulic barrier from the mounding (raising) groundwater. Homestake says that the injected groundwater is not being used for remediation of the alluvial aquifer nor is it used for dilution of the contaminant plume, although it seems to many observers that it would do so anyway.

Separate extraction wells are placed within the contaminant plumes to capture polluted ground water. Homestake says that pumping the extraction wells also helps encourage northward flow. The water is sprayed onto the tailings that “flushes” pollutants from the pile, and they are captured through a tailings’ impoundment “toe drain” and by tailings’ collection wells within the tailings’ impoundment. The polluted water enters a reverse osmosis water treatment plant and is sent to three evaporation ponds. The third tailings’ pond was a subject of controversy, partly because Homestake neighbors/activists wanted more treatment and a larger pond.

EPA states that “4.5 billion gallons of contaminated water have been removed (from the site), and 540 million gallons of treated water have been injected into the aquifer. The contaminant plume has receded back almost three-quarters of a mile into the site boundaries of HMC by injecting fresh water down-gradient of the site.”

Several neighbors, such as Candace Head-Dylla, have cracking concrete pads and foundations that they attribute to overpumping water from the San Andres aquifer to inject into the alluvial aquifer–causing subsidence or sinking of the ground. The three agencies deny that they are pumping enough water to cause this.

“NRC has no time limit to clean the site to reach our standards,” says Buckley concerning the current 2022 estimated completion date.

But BVDA is concerned about “bounce back” of groundwater pollution.

“Bounce back”of groundwater pollution to higher levels than the 2006 alternate contamination standards in groundwater would take place if it turns out that flushing the tailings temporarily reduced the amount of pollutants in the tailings’ pile, but that as all of this pumping and flushing ends, groundwater contamination levels begin to rise again after 2014 or later.

This return of Homestake pollution could happen, maintains BVDA, because it is possible that Homestake is currently pushing polluted groundwater north of the tailings, and that once they stop pumping and pushing that water, there will be a hole left in the groundwater—called a “cone of depression.”

That cone of depression will fill up once again with polluted water that was pushed north of the site and that flows south when the pumping ends. BVDA believes that some of that polluted plume of groundwater that is north of the Homestake site, in addition to flowing from other tailings and mines, could be a result of creating the hydraulic barrier of pumped water.

EPA has asked for a Homestake analysis of bounce-back using part of the tailings to begin, and there will be more monitoring post flushing.

Flushing Alternatives

NRC, EPA and NMED are supportive of Homestake’s flushing out the tailings to remove pollution. This was not true of a fourth agency, the Army Corps of Engineers, who analyzed the site in and concluded in December, 2010, “The flushing of the large tailings’ pile with fresh water largely derived from the Chinle aquifers is unlikely to truly achieve its objective,” and recommended halting the process. The Corps believed that the injection-flushing program was not showing adequate progress in reducing levels within the plume outside of the site.

There are a number of other flushing skeptics.

One is geochemist Abitz, who said, “Flushing hasn’t been done before, and with an unlimited budget you can experiment and see if this works. But fundamentally, when you remediate tailings or a waste site, you are trying to stop the source from polluting rather than temporarily increasing the pollution from the source.

You can move it–costly but ultimately effective. But generally, you either remove or cap the tailings. You stop the driving force causing contamination, which is water.

You completely capture all the water that could enter the site and isolate it from the source of pollution—the tailings. Commonly, you can do that with a slurry wall—that’s a deep trench grouted with bentonite– in front of the tailings and with pumping wells to capture the runoff, and then you cut off all contamination downstream.

Then it’s a matter of time, perhaps several decades. You reroute fresh water, if possible, upstream of the site, but definitely around the tailings.

The tailings are very reactive to water, and I don’t understand the rationale of keeping them open and pushing water into them; I think a lot of money would have been saved had they capped it initially — presuming the cap was strong and impermeable. It costs about one-half million dollars per acre to meet EPA standards and close a site. That could be $120 million, a bit more than has already been spent.

On an EPA-administered Superfund project, you would have taken a comprehensive risk assessment approach for determining how to remediate all contaminants. EPA standards for performance monitoring of a closed uranium mill site are stronger than NRC’s.”

BVDA wants an independent analysis of the option of moving the tailings, much like those at the smaller Moab mill that were moved away from the Colorado River by an act of Congress. They want to know the feasibility of combining Homestake with other mill tailings and moving them to a safe impermeable site that can be lined and monitored. Various ideas such as developing tailings’ slurry to be piped to railroad cars were discussed by members.

The Army Corps in 2010 cautioned about the high generation of climate-changing greenhouse gases in moving the tailings and costs of up to $2.7 billion but pointed out that such a project could be a major source of local employment for a prolonged period of time. BVDA member and former Kerr-McGee executive, Art Gebeau, emphasized, “You wouldn’t need a new uranium industry boom, if you had a boom cleaning up the mess from the old one.”

NRC and EPA refer to a June, 2012 Homestake preliminary study, that Homestake’s Cox said is publicly available, that concluded that moving the pile would “pose a significant potential risk to human health as well as other significant impacts to the environment.”

BWVA’s Johnnie Head said in a letter to the Beacon, “Of course, a feasibility study done by Homestake-Barrick Gold will not show it is feasible to move the tailings’ pile–no one expects any other finding.”

NMED’s Mayerson appears to be observing the experiment of flushing objectively,

“Flushing is controversial; natural seepage from tailings is concentrated and nasty stuff.

Homestake is reducing the mass of contaminants that can be mobilized by water by dilution, so it is promoting seepage to get them out, and that seepage might have occurred over time. Best as I understand it, Homestake thought flushing would reduce pollution violations while remediating. Still it is one of a kind, and I haven’t compared the results of this and more traditional mill tailings remediation.

With the jurisdiction of NRC, the working model is that Homestake proposes what they want to do. If it is logical, presuming it doesn’t harm somebody or the environment, they are allowed to do it to meet their restoration goals.”

Buckley in general concurred: “Homestake makes suggestions, and we evaluate them; this is not managed like an EPA Superfund site.”

Mayerson added, “NMED in other circumstances might have done a more rigorous treatment of their plans for remediation but ultimately our department cannot place ourselves in the position of telling Homestake how to do things, because it makes us liable if our plans don’t work.

Removing tailings would obviously remove the source of contamination, and perhaps it would have been more effective, and more cost effective, 20 years ago.

At this late date, I have real doubts that it would accomplish more than what Homestake is doing would accomplish. Certainly groundwater would not be totally cleaned by moving it; it would take a long time.”

Floods and Tailings’ Breaches

Bluewater Village native and 48-year Murray Acres’ resident, Larry Carver, helped organize the Rio San Jose Flood Control District in the early 1980s after numerous 1970s regional floods caused damage. His concerns about whether the floods caused environmental damages led him to collect resident photographs of floods, and he has provided evidence to NMED that Homestake tailings were breached more than once. He has photographs taken by resident Gladys Chapman in October 1972 showing—combined with floodplain maps—that “flood waters traveled around the northwestern corner of the tailings’ pile and came into our community.”

A second snowmelt flood in mid-January 1979 resulted in the massive breaching of tailings, and according to Carver, on Feb. 16 Homestake breached the tailings to allow the waters to pass through their property. He has a March 1979 Army Corps’ aerial photo as well as area residents’ photos to bolster his argument. (photos)

Murray Acres residents Jerry and Susie Wilcox claim that contaminated flood waters entered the house of Jerry’s parents and left mud throughout the kitchen as well as piled up outside. Numerous BVDA members and residents claim that floods left their property contaminated and potentially spread surface soil and groundwater contamination. This they see as a water, air and health issue.

Jerry’s parents died of cancer.

When questioned on breaches, Cox suggested, “You may be confusing our site with the Church Rock site, operated by United Nuclear Corp.”

Air: Radon and Historical Tailings’ Dust

In 1983, when an official record-of-decision made Homestake a Superfund site for water pollution, “no action” was taken on addressing air issues.

Residents in the Grants’ area know that a dry windy April can move large amounts of soil and dust through the area. Dust blowing across parts of the Bluewater Valley and surrounding areas contained uranium tailings and accompanying radioactive and toxic contaminants when the mills and mines operated and tailings were uncovered. All four mills would have contributed to this. Murray Acres and surrounding subdivisions would have received whatever tailings dust was upstream when the wind blew from that direction.

Tailings’ dust transports radon gas and alpha radiation. As radium 226 decays, it releases radon gas—whether in the tailings or from areas where it has been deposited. Radon is also present naturally in some soils and rocks such as granite. Additionally, if floods breached the tailings in the past, they would have deposited contaminants including radioactive material.

The EPA website states: “When radon is inhaled, the alpha particles from its radioactive decay directly strike sensitive lung tissue causing damage that can lead to lung cancer. However, since radon is a gas, most of it is exhaled. The radiation dose comes largely from radon’s decay products. They enter the lungs on dust particles that lodge in the airways of the lungs. These radionuclides decay quickly, exposing lung tissue to damage and producing other radionuclides that continue damaging the lungs… There is no safe level of radon; any exposure poses some risk of cancer.”

The uncapped tailings were and are a source of radon concern to residents, although the levels that faced uranium miners in the past were sometimes 100 times those found in air at Homestake ambient air monitors.

Reports by the Army Corps of Engineers as well as by EPA subconsultant and BVDA consultant nonprofit Southwest Research and Information Center urged expanded radon monitoring, as well as characterizing the Homestake site more thoroughly to determine what the radon source might be.

Levels of radon gas on the Homestake site are highest on the south side closest to Murrray Acres residences, and almost as high on the southwest side of the site also by residences. Ten years of data showed consistent levels at the highest monitor of close to 1.9 picocuries per liter (pCi/l), which was as much as 10 times the background level, monitored at Bluewater Village.

If a level of 2.0 pCi/l were inside a house, the agency suggests the owner consider ventilating the house since EPA estimates that a nonsmoker exposed to 2.0 pCi/l of radon indoors has a lifetime lung cancer risk of four in 1,000.

EPA has requested that Homestake recalculate the rates of radon decay in the tailings and recognizes that these are areas of potential health concern, but they are not urging a change in remediation at the site and do not yet recognize radon emissions from the site as a health hazard.

The agency is currently carrying out remediation—ventilation– in 10 nearby houses out of 75 analyzed that have indoor radon levels higher than the standard of 4.0 pCi/l.

EPA’s Appaji said that, “Because of radon concerns in the homes, EPA initiated a radon study at the site beginning in September 2010… collected more than 1,500 radon samples inside homes and on HMC property to determine if the community is exposed to radon from the site. EPA is currently reviewing all of the data.”

BVDA’s Art Gebeau believes that it is important for the agency to determine whether some of the houses in the area were built on slabs before

Category: Archives

Leave a Reply