Skip directly to search Skip directly to A to Z list Skip directly to site content

PUBLIC HEALTH ASSESSMENT

PANTEX PLANT
AMARILLO, CARSON COUNTY, TEXAS

APPENDIX F

Public Comments on the Pantex Plant Public Health Assessment and ATSDR's Responses

ATSDR received comments on the Pantex Plant Public Health Assessment, Public CommentRelease (December 11, 1997), from individuals, organizations, and agencies. We thank all ofthose who took time to comment. The comments received reflect a strong and sincere interestfrom people in the communities surrounding the Pantex Plant. This appendix includes a listingof the public comments received and ATSDR's responses.

The comments received covered many topics. Recommendations included asking us to deletewords, add supporting documentation, and reconsider conclusions: some people wanted us tosoften them and some wanted us to strengthen them. One commenter recommended that thepublic reject the assessment out of hand.

A major concern, expressed repeatedly throughout the comments and questions received byATSDR, was how much contamination in the environment, or exposure to that contamination, isenough to regard that contamination as a health hazard.

A partial answer to that question--how much of a substance is a health hazard?--is that itdepends on the situation. ATSDR does not maintain a set of values for substances that definewhat is and what is not a health hazard. We have health-based comparison values for somechemicals that we use to initially screen environmental data. However, exceeding screeningvalues does not mean a substance is a health hazard. For each situation, we consider whatexposure assumptions are appropriate and what is known about the toxicity of the substance. Weexplore the answer to this question in greater depth in our responses to specific comments.

Related to the question of hazard, several commenters specifically noted that with radioactivematerials, there can be no safe level of exposure and any contamination of radioactive materialsin the environment poses a public health hazard. In our opinion, based on the overwhelmingbody of scientific knowledge, this may not be true. We recognize that people who assign risks toradioactive materials usually assume there exists some incremental risk from exposure toradioactive materials no matter how small the quantity of radioactive material in the environment(i.e., an assumption of the no-threshold models), and they calculate incremental risks by linearlyextrapolating risks from higher radiation doses. This approach is a conservative one that is usedby regulatory agencies to provide adequate protection for workers and the general public frompotential radiation hazards. But this assumption is not necessarily an accurate description of thetrue risks from exposures to low levels of radiation. Unfortunately, we cannot measure thoserisks directly using currently available scientific methods (e.g., epidemiology and biologicaltesting). Furthermore, considerable mounting evidence from the fields of genetics and cancerresearch, as well as numerous epidemiological studies refute the linear, no-threshold risk modelsfor exposures to low levels of radiation. Rather than assuming that any quantity of radionuclidesin the environment will cause adverse health effects, we consider both existing radionuclide-specific toxicological data and the ongoing recommendations of radiation advisory bodies (e.g.,the International Commission on Radiological Protection [ICRP] and the National Council onRadiation Protection and Measurements [NCRP]). ATSDR believes this to be the most sound scientific approach.

Finally; at ATSDR, we bring to bear the collective education and experience of public healthscientists, health physicists, toxicologists, epidemiologists, environmental health scientists,physicians, and others, to the assessment process. In this environment, we work to keep currenton scientific and social issues, and discuss, both internally and externally, different approaches tothe assessment process. Nevertheless, we recognize that not all people will interpret the sameinformation the same way we did, and we respect others who may have opinions different from ours.

We address the comments received in the following section. Page number references for thecomments received by ATSDR (comments are numbered and in bold print) refer to text in theprevious (Initial Release and Public Comment Release) versions of the Pantex Plant public healthassessment (PHA). Page number references for the ATSDR response to each comment indicatewhere text occurs in this document--not to the pages where the text occurred in earlier versionsof the Pantex Plant PHA.

ATSDR responses are provided after each comment or group of comments.

1. The health outcomes section of the Pantex PHA ... definitely references recent Texas cancer incidence and mortality statistics. They note an excess of CLL that "needs tobe investigated:, as well as an excess of prostate cancer and muscular dystrophy deaths,and some other assorted findings. The previously reported Carson County excess leukemiamortality (SMR=1.5, not signif.) is not referred to, but the combined data in this reportshow Carson County leukemia deaths to still be elevated for the period 1985-1994(SMR=1.9, not signif.). I think this deserves mention and the relevant table is on pg. 112.

Response: We are not entirely sure which previous report the commentor is referring to; however, in both instances the SMRs were not significant. Additionally, with respect to thecombined data, the SMR is small (1.9), the confidence interval is relatively narrow (0.98,3.32),and the category "leukemia" includes all types of leukemia, some of which may have differingetiologies. We do not believe that a discussion of these data would add to the report.

2. On pg. 52, there is a sentence in the first full paragraph that the "statistically significant excess could be the result of slight (non-significant) elevations in deaths frommany different types of cancer or the result of a large increase deaths in from one or twotypes of cancer". This is one garbled sentence - it should say "increase in deaths in one ortwo types of cancer". But more importantly, which is it in Potter County males? Theyclearly have the data to answer that, but leave the reader guessing.

Response: Apparently the word "in" was misplaced. The sentence should read " a large increase in deaths from one or two types of cancer". The change has been incorporated. Theproblem with identifying the exact cancer types is that all cancers, with the exception of prostatecancer are reported as a group category referred to as "All Types". This is illustrated in Tables 16 and 17. Therefore, we know prostate cancer is elevated in this particular population;however, the remaining specific type or types cannot be identified with the current database.

3. On pg. 52, at the bottom, there is a statement that "one of three persons alive today will develop some type of cancer in their lifetime". Actually, its gone up and is nowmore like 4 out of 10 (more in males). The new NCI SEER report has that figure.

Response: We have rewritten the paragraph to read: "Approximately four out of every ten persons alive today will be diagnosed with some type of cancer in their lifetime."

4. On pg. 55, there is the old "smoking and diet" argument posed against the environmental/occupational causes. This is unnecessary in a PHA about a Superfund site.

Response: This statement is written in response to the question; "can the Pantex Plant be the cause of the higher than expected number of people with cancer that the TCR observed". Wedo not view this to be an argument posing smoking and diet against environmental andoccupation. The fact that the majority of cancers can be attributed to individual behaviors is notin dispute and does not exclude the possibility that some cancers may be caused byenvironmental or occupational exposures. It is important that residents concerned with theoccurrence of cancer in their neighborhoods have knowledge of the most common causes ofcancer. The presence of cancer in a neighborhood might be alarming; however, people beingdiagnosed with cancer is not unusual. As the reviewer pointed out in Comment 3 approximately40 percent of the population will be diagnosed with cancer at some time in their lives (42.52%for males and 38.88% for females). One of the functions of the PHA is to address residentconcerns and provide information so that people can have a better knowledge base from which todraw their conclusions and plan future life choices.

5. Use of definitive language that lacks support - The use of definitive language is inappropriate for this Public Health Assessment. ATSDR PHAs are exploratory,preliminary, inventorying types of studies. They are not designed to provide definitiveresults. Moreover, given the limitations of this review (in large part because of the dataavailable for the review), I do not believe that ATSDR can use definitive language in itsconclusions about whether there are, or were, any risks to public health. In my opinion,the limitations of ATSDR's approach warrant more cautious conclusions. In general, Ifind this report was written with a bias toward the managers of the facility. When indoubt, the report authors have injected conclusions that appear to be intended to reassurethe public of there being minimal if any risk.

ATSDR does this even when they have doubts. On page 20 ATSDR writes "contaminantconcentrations detected on- and off-site are compared to values that are believed to bewithout adverse health effects upon exposure." (Emphasis is mine). So, on pg. 20 ATSDRnotes some uncertainty about the protection provided by their (unstated) screeningstandards. But later, in the conclusions and analysis. ATSDR forgets about thesequalifiers and makes statements without qualifiers.

Response: A qualifier has been added.

6. On pg. 48, the report states that it is "difficult to provide meaningful interpretation of results" related to fetal death frequencies. In the Discussion section on thesame page (48) the report states that "it would be difficult to attach much importance tofindings of statistical significance because our confidence in the precision of the data wouldbe limited." Yet, ATSDR seems to have no trouble attaching importance to findings of nostatistical significance that are based on inadequate (missing and unreliable) data. Theburden of proof is not balanced, and more attention seems to be given to the evidencesuggesting negative findings that to the evidence suggesting positive findings. A betterapproach would be for ATSDR to suggest how to correct the lack of "precision of the data"(if possible) in order to reach more reliable conclusions. This is clearly within the realm ofwhat ATSDR can recommend in a PHA.

Response: With regard to the health outcome data, we reviewed available health outcome data to determine if the observed amount of disease in the area is greater than what might beexpected. During this process data are tested for statistical significance; if the data are found tobe statistically significant we examine the data to try to make some conclusion as to whether the"statistically significant" finding is significant with respect to the everyday use of the word. Indoing so we look at such factors as the magnitude of observed cases, the magnitude of theexpected cases, the specificity of the category examined, and the precision of the estimate asmeasured by the width of the confidence interval. Contrary to the reviewers comment, withrespect to health outcome data, we actually pay more attention to positive findings than negativefindings. General limitations with respect to health outcome data quality are discussed in thedocument.

7. On page 25 ATSDR writes that "no pesticides, herbicides,.... have been detected in perched groundwater." This would seem to argue that these sources CANNOT beproblems, at least from groundwater exposure; this seems to be the same line of reasoningused to claim that there CANNOT be any harmful effects from Pantex-relatedcontamination. Is ATSDR willing to make this kind of definitive claim?

Response: It is agreed that pesticides and herbicides are not a problem in groundwater because they have not been detected in groundwater. ATSDR's conclusions are based onenvironmental sampling data. If contaminants, as mentioned in this comment, are not detectedduring monitoring, then it can be concluded by weight-of-evdence that no exposure is occurring. One must have a contaminant present to have an exposure.

8. A large body of case studies and research on risk communication suggests that the style and tone of the PHA are the very kinds that should be avoided. For example,definitive language that seems to dismiss community concerns (for example, on page. 55)and unclear and technical writing are all factors that have been observed to contribute tolack of trust and credibility in scientific studies--especially in situations where there arealready public concerns about the accountability or credibility of an agency/organizationand the legitimacy of a process. Moreover, the writing of this PHA is filled with redundantstatements that repeatedly suggest that the reader "not worry." Yet, the claims are basedon inadequate evidence and an over-reliance on negative findings (which suggest no harm)at the expense of inconclusive or positive findings (which suggest some incremental risk). Adocument, such as a PHA that is intended for a public audience has a special responsibilityto provide information in a way that is clear, complete, and responsive to multipleaudiences. This document clearly fails to achieve these responsibilities in regard tointerested and affected community members who do not have specializedscientific/technical training.

Response: ATSDR attempted to find information that would lead us to believe people were exposed to releases from the Pantex Plant in quantities that could cause adverse health effects,and was unsuccessful. We have had health physicists, public health experts, and occupationalmedical professionals help write and review this public health assessment. None of them hasmade this observation.

9. Inadequate discussion of comparison values and safety thresholds - As I noted in my presentation/paper to the PPCAB, regulatory standards for radionuclides are risk-based--that is they do not provide levels below which safety is ensured--only that risks arebelow a certain level. Any additional exposure to radionuclides can have adverse healtheffects, although the probability of harm decreases as exposure decreases. Yet, on pg. 36the report states "The elevated levels of tritium, however, have NOT resulted in radiationexposures or doses above levels that would cause adverse health effects." The definitivetone of this statement suggests that there are levels of exposure to tritium below which noadverse health effects can occur. In other words, any level of exposure has someincremental non-zero risk of causing harm. This risk may be small, but this is a differentclaim than that there is NO risk.

Furthermore, claims, in the report, of minimal risk below some threshold of acceptabilityare not based on the factual evidence in a clear way. ATSDR does not clearly state thelevels at which exposures to contaminants (such as tritium) would be expected to causeharm. What level of exposure is assumed to cause a high enough probability of harm thatit would be called "significant"? What are the "comparison values" discussed on pg. 20(and implied on pg. 36 as well as other places in the text)? How close areestimated/measured values to the comparison values? How were the comparison valuesderived so as to protect the "most sensitive segment of the population"? How douncertainties and interindividual variabilities affect the relationships to thecomparison/safety levels? Are safety factors used? Do they have any basis in biologicalunderstanding (e.g., pharmacokinetic modeling) or are they derived by dividing by 10 (atraditional, yet arbitrary number)? Without this type of information in the report readersare unable to evaluate the reports claims completely. A reader cannot evaluate the validityof conclusions and the adequacy of assumptions if they are hidden from view.

On page 33 ATSDR writes "in 1975 elevated levels of uranium were found in soils north ofZone 4 but the values were still less than 0.11 Bq/g, about 3 times above backgroundlevels." Those concentrations are "similar" to background levels. What does "similar"mean?

On pg. 35-36 they discuss tritium releases and exposures. In the second to last paragraphthey write that in 1982 tritium levels in the air ranged from 0.059 - 0.24 Bq/m3, or 1.6-6.4pCi/m3. According to the EPA, National background levels are about 300 pCi/Liter.

1000 Liters = 1m3 according to my calculations, which means the 1982 levels ranged from1600 - 6400 pCi/m3. This is 5 to 21 + times more than average national background levels. At what point are elevated levels of tritium expected to cause harm?

On page 33, ATSDR wrote that the radiological dose expected from groundwatercontamination is less than 4 mrem per year. The issue is cumulative dose, and 4 mremadds to the cumulative dose, and since everyone agrees that all additional exposures havesome risk, 4 mrem implies more risk. How much more risk is the question. This sameissue comes up on pg. 34 when they write "there were no levels of uranium or plutoniumfound that would be considered a health hazard." ANY additional exposure presentsadditional risk, which is the same as saying additional hazard. So, how does ATSDR define"a health hazard"? What level of risk must be exceeded?

Response: We believe the commentor is referring to the Linear-No-Threshold Hypothesis (LNT) which was established as a regulatory framework. An hypothesis is a theory and LNT hasnever been shown to be fact. LNT was based on one set of experiments in the 1920s using fruitflies. Data in the scientific literature does not support the concept of LNT. In fact, much of thedata, both laboratory and human, shows that a threshold does exist in a response to radiationexposure and dose. This has led to members of the scientific community challenging the use ofLNT. Based on the available radiation protection information, radiation health information, andother scientific peer reviewed data the levels of dose associated with releases from the PantexPlant are not expected to cause adverse health effects.

Radiation evaluations are not performed in a manner such as those prepared for chemicalexposures. Chemical toxicological information is based on experiments with laboratory animalsand limited experimental data, with insufficient information on pharmacokinetics associated withchemical exposure. Because of these limited data, toxicologists use factors to ensure safety inthe case of exposures. In some cases, these factors may result in reductions 10, 100, 1000 ormore. ATSDR as well as other federal agencies have developed comparison values for theevaluation of chemical exposures; ATSDR has not developed comparison values forradionuclides in the environment. Therefore, ATSDR uses a different protocol to evaluation theradiation levels in the environment. In the case of radiation dose estimates, the data are moreprecise as the location and metabolism can easily be tracked. Furthermore, the energy depositedwithin the specified tissues have been calculated by international organizations. These energycalculations have resulted in the tabulation of dose conversion factors (DCF). These DCFs wereused by ATSDR to develop the radiological dose assessment.

In discussing background levels and other levels "similar," or comparable to background, onemust realize that variations exist in nature. In the evaluation of background levels, statistics suchas the 2 sigma counting error are very important. This error represents the 95% confidence levelsof the determinations. In the evaluation of uranium levels associated with the Amarillo area, thevariations in background and the associated 2 sigma error suggest that the levels are "similar"throughout the area.

The commentor is misquoting the scientific literature. The value he is quoting is the tritiumlevels found throughout the country in surface waters. We recommend that he review anysurface water data prepared by the US Environmental Protection Agency for their EnvironmentalRadiation Ambient Monitoring System. To further show that the commentor is incorrect, onecan calculate the actual tritium concentration. As an example, according to the March 1979NCRP Report Number 62 (Tritium in the Environment), during the height of atmosphericnuclear testing, the concentration of tritium was 0.48 atoms per cubic centimeter of air at sealevel. Using standard values and physical constants, it can be easily shown that thisconcentration of tritium was 0.3 picocuries per cubic meter, a value 10,000 lower than thatquoted by the commentor. Other estimates can be made using the total amount of tritium in theatmosphere and taking the total volume of the atmosphere and these estimates are even lowerthan the value of 0.3 picocuries per cubic meter.

See our response above regarding thresholds, and risks. Based on information being developed,current data suggests that a radiological dose of 2 rem to the entire body may exhibit adversehealth effects. In the case of external exposures, ATSDR has issued health advisories when theexternal whole body dose, over a period of time, has exceeded 500 millirem per year to amember of the public. Without ATSDR involvement, exposures above this level may well havecontinued far into the future. The commentor can request copies of these health advisories forhis information. The sites at which these health advisories were issued include: the RadiumChemical Company, Queens, New York; the Brown Vandever Navajo Uranium Mines inBluewater, New Mexico; Austin Avenue, Lansdowne, Pennsylvania; and the H&K AircraftComponents and D&L Sales in Benton Harbor and Belding, Michigan.

10. For example, ATSDR writes in regard to groundwater that "concentrations were below health screening values" (e.g. pg. 25). What are these values? How close are theactual values to the screening levels? Are concentrations likely to be equal to or exceedthese screening levels sometime in the future because of additional releases and movementof contaminants?

Response: The current ATSDR health comparison values selected for those contaminants related to the comment are 400 ppb for HMX explosive; 30 ppb for RDX explosive; 5 ppb for the1,3,5-TNB and 2,4,6-TNT explosive; 20 ppb for 2,4-DNT explosive; 5 ppb for benzene, 1,2-dichloroethane, methylene chloride and trichloroethane; 300 ppb for tetrachloroethane; 100 ppbfor total chromium; and 50 ppb for hexavalent chromium. It is critical to note that, even if thecontaminant concentrations should exceed those values in the future, a resident would have to bedrawing water from that particular perched aquifer, discussed in this public health assessment,for a completed exposure pathway to occur. To date, ATSDR has not been able to identify anyresidents utilizing that particular perched aquifer downgradient of the contaminant plume.

ATSDR's comparison values are included in the ATSDR database, HAZDAT, which is availableto the public on ATSDR's web page (http://www.atsdr.cdc.gov/). It is critical toemphasize that the choice of which comparison value to use for a particular contaminant isdetermined by the exposure scenario being evaluated and the health assessor's professionaljudgement. There is no set rule for comparison value selection. Data that exceed our screeningvalues do not automatically represent a public health hazard. We also consider the relativeaccessibility of the contamination, which populations may be exposed, the magnitude of theexposure, and the toxicity of the contaminants. Our public health calls are weight-of-evidencedecisions.

11. ATSDR does not discuss issues of cumulative and multiple exposures. An uniformed reader might be led to believe these are irrelevant. Yet, there is no evidence thateven if exposures to single contaminants are below regulatory standards, that there can beno adverse effect from the cumulative/multiple exposures. This issue needs to be addressedin a clear and thorough manner.

Response: A discussion of additive and synergistic effects has been added to the Toxicological Evaluation Section.

12. Validity of databases and monitoring systems - There is no evaluation of the adequacy, completeness, or validity of the databases that ATSDR uses. They do makecomments that information is missing (e.g., monitoring for particular contaminants beganas late as the 1980s), not reliable (e.g., disease incidence, infant death certificates), etc. However, they do tell us how important these missing, inaccurate, incomplete, etc. data are. How much uncertainty do they introduce? Is there any way to improve the databases? ATSDR can make these kinds of recommendations as part of PHAs. There should be lesspassive acceptance of the data as provided by Pantex Plant and more evaluation as to datagaps, uncertainties, inconsistencies, and reliability. Again, this kind of discussion wouldprovide readers with better understandings and abilities to evaluate the reports claimscompletely.

Response: ATSDR is obliged to make a public health call, which is based on an interpretation of available databases. In a perfect world, historical data would be of the qualitywe collect today; however, we do not believe the historical databases are invalid because they donot meet today's standards. Even if there are data gaps, the data we have are numerous andconsistent enough that they would require large deviations to move the average valuessignificantly. None of our ways of looking at the data (e.g., air concentrations, release quantities,CAP88 modeling, soil concentrations) indicate that there are large inconsistencies in the data.We cannot turn back the clock and sample people's blood or urine, which would provide the bestmeasure of exposures to environmental contamination. We have to use the information that wehave available--usually, environmental sampling data (such as concentrations of contaminants inthe air and water)--to estimate people's exposures, and available health outcome data todetermine if adverse outcomes are elevated for an area relative to other areas. Although notperfect, ATSDR concluded that databases reviewed for the Pantex Plant public health assessmentwere sufficient and appropriate.

To improve the quality of its health outcome database, TDH is currently in the process ofexpanding an active birth defect surveillance system into the Pantex area beginning with 1998childbirth deliveries. Data from this active surveillance system will be used to evaluate theaccuracy and completeness of vital records in the Pantex area.

13. Specifically in regard to tritium, there are questions about the available data. It is unclear whether the measurement techniques used account for the amount of organicallybound tritium in plants.

There is evidence that there can be more organically bound tritium in plants than theamount that is present in the free water in the plants. Do they measure this? Why not,since analytic techniques are available?

In addition, the Pantex 1995 Environmental Report claims that higher observed levels inplants may have been due to a change in laboratories--not in actual levels. Did ATSDRevaluate this possibility? This kind of problem points to potential problems in extantdatabases, which can affect analyses. Moreover, why do they use background levels (in the1995 report) as the 1989-1991 observed values? There are, apparently, tritium monitoringdata from as early as 1974 (see page 32).

What can be told about the adequacy of the monitoring systems? Were they evaluated anddoes ATSDR have any recommendations about how to improve them? For example,potential problems are caused by conducting discrete monitoring for contaminants on pre-known schedules (pg. 28). What about the distribution of monitoring wells? There seem tobe none in the southeast buffer area--so how can anyone know with a high degree ofcertainty where the groundwater plumes are going? In addition, on pg. 34 ATSDR writesthat no uranium releases were reported in 1987, yet samples show high uranium in soils(3rd full paragraph from top). Are these samples from 1987? If so, what does this sayabout the quality of the monitoring system and the reporting system? In the 5th fullparagraph ATSDR writes that "actual concentrations could be higher or lower thanreported because uranium was present in quality control samples." Again, what does thissay about the reliability of the quality control? Or of the sampling system? Or of thereporting system? They can't all be working right.

Response: The tritium measured in vegetation was used to determine the tritium in biota. Organically bound tritium (OBT), however, relates to tritium bound to organic molecules. Depending on the type of organic compound to which the tritium is bound, the biological half-life will vary. Pantex did not determine the OBT in biota; however, the dose assessmentprepared by ATSDR took into account the total tritium in the vegetation.

ATSDR reviewed the monitor locations, background locations, and windrose charts. ATSDRbelieves the monitoring system as it exists at the Pantex Plant is adequate for the purposes ofenvironmental assessment.

DOE and the Pantex Plant are aware of the quality control issues and are taking appropriate measures.

14. The contamination of the perched aquifer is not a problem, in the view of ATSDR, because it is not used for drinking water. They then recommend that institutionalcontrols be implemented (pg.65) to ensure that exposures not occur in the future. Are suchinstitutional controls likely to succeed? What evidence/evaluation of institutional controlsin such situations exists? Should they be attempting to clean-up? Given the lack ofinformation about the hydrology of the aquifers (pg.7), why doesn't ATSDR recommendadditional research on characterizing the hydrology?

Again in regard to groundwater contamination, ATSDR claims that there are no completedpathways of exposure through this media because domestic wells in one location werecapped/modified. Is there continuous monitoring of this "potential pathway"?

Response: According to TNRCC, the current limits of the contaminated perched aquifer associated with the Pantex Plant are delineated; therefore, ATSDR does not recommendadditional hydrogeological studies of that particular perched aquifer at this time. A single privatedrinking water well, drawing water from the Ogallala and not the contaminated perched aquifer,is located downgradient of the contaminant plume. That well is monitored by both Pantex Plantand TNRCC staff to ensure that contamination from the perched aquifer does not migrate to theOgallala without detection. Given TNRCC's reputation for proactive oversight and the fact thatthe office responsible for Pantex Plant environmental activity regulation is located in Amarillo,we feel confident that the recommended institutional controls will be successful.

15. Inaccurate assessment of pathways - The definition of "potential pathway" and the way it is used in the Pathway Analysis section is odd and unclear. On pg. 38 a"pathway" is defined. A "potential pathway" is also defined--it is one in which one of thefive components is missing. The report then goes on to claim that "a potential pathway waseliminated because the old well was closed and sealed, and the new well was constructed insuch a manner as to prevent intrusion of the contaminated perched aquifer" (pg.38). Butthis is a potential pathway according to the definition given one paragraph earlier, "anexposure pathway is defined as potential if one of more of the necessary components ismissing or if information for evaluating the pathway is not available." By closing andsealing a well one of the components of a pathway is eliminated, but it is still a potentialpathway. This strange writing suggests sloppiness in the analysis and/or a rush tominimize understandings of risk.

More confusion arises when a pathway is defined as potential when "information forevaluating the pathway is not available." There is an important distinction that should bemade when claiming a pathway is not complete because:

a)we have enough information to evaluate it and we can conclude within reasonable levels of certainty that a contaminant will not lead to exposure ofa population, and

b)we do NOT have enough information to know whether a contaminant can lead to exposure of a population.

ATSDR conflates the two. In the second case (where information is lacking) definitivelanguage about no risks is highly inappropriate. The community would be much betterserved with a clear analysis of what information is lacking, whether it can be obtained (andwith how much difficulty), how reliable it might be, etc. Yet, ATSDR makes definitiveclaims and it provides no help in evaluating the quality of available data or the importanceof missing data.

Finally, ATSDR does not clearly distinguish between past, present, and future potential orcompleted pathways. Clearly, there were completed pathways with regard to contaminantsin a domestic drinking well. There were emissions of uranium and other contaminantsfrom high explosives testing and burning of materials. There were tritium releases that ledto elevated levels near the plant. These were completed pathways. At the same time, thereare still off-site emissions from high explosive testing and burning of materials. Thus, thestatement "No on-site potential or completed exposure pathways are evident from PantexPlant activities" (pg. 38) is factually incorrect. One might be able to argue that thepathways did not lead to high risk exposures, but this is a different issue. ATSDR seems toequate the existence of a (potential or completed) pathway with the existence of high-riskexposures in a population. These are analytically different; ATSDR's logic is confusingand lacks credibility in the pathways analysis section.

Response: The pathways discussion has been revised.

16. The legal definition of a Health Assessment has not been met - The legal definition of a health assessment, under CERCLA (Comprehensive Environmental Response,Compensation, and Liability Act of 1980), is on the inside cover of this assessment, and isreferred to on page i. Compliance with the following items within this legal definition werenot met:

"The health assessment shall include...the comparison of expected human exposure levels tothe short-term and long-term health effects associated with identified hazardoussubstances, and any available recommended exposure or tolerance limits for suchhazardous substances, and the comparison of existing morbidity and mortality data ondiseases that may be associated with the observed levels of exposure."

Nowhere in this document can this information be located. Although there are frequentreferences to regulatory jargon such as maximum contaminant levels (MCLs), existingregulatory limits are not identified in a comprehensive and clear manner.

One result of this oversight is that the assessment is cluttered with a plethora of regulatorylanguage that has no meaning to the average reader. For example, in Section IV.C.3.aalone (groundwater contamination), there are references to MCL's, risk reductionstandards (RRS), health screening values, background levels, and derived concentrationguides. Several of these, but not all, are defined on pages 21-22, but none of these arequantified for any contaminant.

A second result is that readers have no indication of the proximity of contaminant levels toregulatory guidelines. All that is known is whether they are above, or beyond, the limits. Considering the frequent use of the word "significant" and other qualifiers in the report,this is a disturbing omission.

Response: Public health implications, including a comparison of health outcome data (such as existing morbidity and mortality data) are discussed in Section VI. The current ATSDRhealth comparison values selected for those contaminants related to the comment are 400 ppb forHMX explosive; 30 ppb for RDX explosive; 5 ppb for the 1,3,5-TNB and 2,4,6-TNT explosive;20 ppb for 2,4-DNT explosive; 5 ppb for benzene, 1,2-dichloroethane, methylene chloride andtrichloroethane; 300 ppb for tetrachloroethane; 100 ppb for total chromium; and 50 ppb forhexavalent chromium.

17. The Assessment fails to follow its own stated procedures. The Forward contains a discussion of the procedures ATSDR will follow in a health assessment -

a. It states that "when there is not enough environmental information available, the reportwill indicate what further sampling data is needed." In this report there is not discussionor reference as to the sufficiency of the utilized data.

b. If "people have or could come into contact with hazardous substances," ATSDR isresponsible for evaluating "whether or not there will be any harmful effects from theseexposures." While ATSDR acknowledges the chemical contamination of the perchedaquifer, it evaded its responsibility to determine if people have come into contact with thiswater source in the past, or what the harmful effects could be if people did come intocontact with it in the future.

Since the perched aquifer is contaminated offsite and there are wells that are known toaccess it, ATSDR should not dismiss this issue by stating the water is not presently used. Inreality, the threat to people does exist, and ATSDR should assess this threat fully andclearly. The threat does not vanish because people are prevented from using this water anymore than banning fishing in a polluted stream removes the threat of ingestingcontaminated fish.

c. ATSDR admits that "the science of environmental health is still developing, andsometimes scientific information on the health effects of certain substances is not available. When this is so, the report will suggest what further research studies are needed." Thereare no suggestions for further research needs in this assessment. This is particularlydisturbing given the definitive nature of the preliminary assessment's conclusions. Thereader is given the clear impression that no further research needs are necessary and thatperhaps the science is actually fully developed.

d. ATSDR "can issue a public health advisory warning people of the danger" posed by anurgent health threat." Since ATSDR states that the perched aquifer would requiretreatment prior to it being safe, the action plan should consider a health advisory for theperched aquifer. The importance of this measure is heightened by the fact that DOE isunaware of the exact boundaries of the perched layer, and only has an estimation of theboundary at the present time.

Response:

(a) Although not perfect, ATSDR concluded that environmental sampling databases, reviewed for the Pantex Plant public health assessment, were sufficient and appropriate.

(b) ATSDR, TNRCC, and Pantex Plant staff have been unable to identify any residents utilizing the particular perched aquifer discussed in the Pantex Plant public health assessment asa drinking water source. Local residents and the commentor have been requested to provide theactual locations of those private wells, but have apparently been unable to do so.

(c) To improve the quality of its health outcome database, TDH is currently in the process of expanding an active birth defect surveillance system into the Pantex area beginning with 1998childbirth deliveries. Data from this active surveillance system will be used to enhance theaccuracy and completeness of vital records in the Pantex area.

(d) The exposures from Pantex operations do not meet the requirements for a health advisory. For additional information, see 57 Federal Register 58504 (December 10, 1992) and58 Federal Register 42732 (August 11, 1993).

18. The Assessment takes a limited approach to contaminant exposure - ATSDR provides no mention of the possible health effects of exposure to multiple contaminants. This omission creates the impression, without any scientific backing, that people can beexposed to multiple contaminants as long as exposure to no individual contaminant exceedsregulatory limits.

ATSDR provides no discussion of the cumulative effects of multiple exposures to multiplecontaminants. At a minimum, ATSDR should briefly review the status of knowledge inthis field.

Response: A discussion of additive and synergistic effects has been added to the Toxicological Evaluation Section.

19. The Assessment fails to analyze the validity of data sources - There is not a single discussion pertaining to the limitations of the environmental data being used to make theassessment. This is particularly notable since ATSDR states that some systematic studies never occurred before 1995.

Response: See Section IV.D, Quality Assurance and Quality Control.

20. The data base is clearly insufficient to make definitive conclusions - While the assessment makes definitive conclusions about in incidence of cancer, data prior to 1973 isabsent, and the early data is admittedly weak. There is also a lack of discussion on thelimitations of existing data. Also, since increased regulatory oversight began in the late1980's, ATSDR should evaluate whether data from this latter era is reflective of historic uses.

Response: Limitations associated with the health outcome data are discussed throughout the public health implications section. We reviewed cancer incidence data (1985 to 1993) andmortality data (1985- 1994) to answer the question posed by local residents " is there too muchcancer in the area. According to the Texas Cancer Registry, Texas has cancer incidence datagoing back to 1976. Incidence data prior to 1976 is very limited and the quality is poor.

21. The Assessment contains numerous errors and inaccuracies -

a. The population estimates for the 1 mile radius are inaccurate. For such a small population, it is curious to see that statistically rigorous methods were used to estimatepopulation densities and demographics. According to a Pantex neighbor, there are at leastfour children under six years old within one mile of the plant. ATSDR claims there is onlya single child under six years old--a 400% error.

b. On Page 25, ATSDR reported, "The risk reduction levels are generally as stringent as the Safe Drinking Water Act MCL's. "Risk reduction level three, which the PantexPlant Draft Baseline Risk Assessment Work Plan proposes for the perched aquifer, callsfor only partial remediation with long-term site controls in some cases.

c. Page 25. "Two new monitoring wells were installed in the perched aquifer on the off-site property in May, 1996. Sampling of those off-site wells in May 1996 also detectedexplosive constituents; however, concentrations were below health screening values." It isunclear which wells ATSDR is referring to. However, wells PX 06-1030 and PX 06-1031,which are offsite perched monitoring wells, have had RDX levels ranging from 1.54 to 354parts per billion between June, 1996 and January, 1997 (TNRCC data). All but onereading exceeded the EPA Health Advisory Level for Lifetime Exposure of 2 parts perbillion.

Response:

(a) The ATSDR demographic data source was the U.S. Bureau of the Census 1990 Census. Based on residents' input, the number of children under 6 years old residing within one mile ofthe plant has been corrected.

(b) The operative phrase in the statement is "generally as stringent as the Safe Drinking Water Act MCL's". TNRCC has approved the workplan for the perched aquifer, which is notused as a drinking water source, as appropriate under current conditions.

(c) This paragraph has been revised.

22. The assessment uses language that understates or masks hazardous activities - For example, on page 4, ATSDR reported, "a small fraction of the recovered explosives isthermally treated." ATSDR should report the quantities of recovered explosives that arethermally treated," and identify thermal treatment as open-air burning. Failure to do soconveys technical legitimacy to an archaic method of waste disposal.

Response: The Pantex Plant public health assessment focuses on the air monitoring program and human exposure related to those activities.

Open burning of high explosives as a means of disposal is currently permitted at five other sitesin Texas. Lone Star Army Ammunition Plant and Red River Army Depot in Bowie County, FortHood in Coryell County, and Camp Bullis in Bexar County are Department of Defense facilities. The GOEX Plant, a private operation in Johnson County, is permitted to dispose of highexplosives used in oil drilling applications. Open burning is currently considered a safe andeffective means of high expolosive disposal, and is a common method employed throughout theU.S. by both government and private organizations.

23. The assessment is burdened by unprofessional writing and premature conclusions - The narrative contains several examples of overemphasis placed on words. For example, on page 38 it states that "the elevated air levels of tritium, however, haveNOT resulted in radiation exposures or doses above levels that would cause adverse healtheffects." If ATSDR wishes to be a credible, it should make every effort to eliminate a defensive and strident tone in its writing.

In light of the identified shortcomings, with this draft report, the definitive conclusionswithin it seem unjustifiable at this time. ATSDR appears to be more concerned withpacifying public opinion than fulfilling its role of neutral investigator.

Response: Based on the available peer reviewed scientific data, radiation doses at the levels experienced through off-site exposures have never been shown to cause any adverse healtheffects. Therefore, we believe no change in wording is necessary.

24. The important role of ATSDR is to:

  1. Verify the validity and limitations of available data sources.
  2. Identify data needs necessary to reach more definitive conclusions.
  3. Provide citizens with the necessary information they need to help formulatetheir own opinions.
  4. Provide conclusions that accurately reflect the full range of findings, both positive and negative.
 

Response: Comment noted.

25. I 'm not sure this assessment was really needed.

Response: Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), commonly known as the "Superfund" Act, ATSDR ismandated to prepare public health assessments for all sites on EPA's National Priorities List.

The Pantex Plant Department of Energy (DOE) site was proposed for the EnvironmentalProtection Agency's (EPA) National Priorities List (NPL) in July 1991. In August 1991,representatives of Panhandle Area Neighbors and Landowners (PANAL), Peace Farm, SeriousTexans Against Nuclear Dumping (STAND), and the Texas Nuclear Waste Task Forcepetitioned the Agency for Toxic Substances and Disease Registry (ATSDR) to conduct a publichealth assessment of the Pantex Plant; however, because of the proposed listing, ATSDR wasalready mandated to conduct a public health assessment of the site. The site was subsequentlyofficially added to the NPL in May 1994.

26. What was the total cost of this report?

Response: The average cost of a completed public health assessment is approximately $200,000. However, cost can vary greatly depending on the commitment of resources to the site.

27. Cancer deaths did not reflect instances of cancer/cancer death of individuals once having lived in the area but are now at other locations.

Response: This limitation has been added to the discussion of cancer mortality data.

28. I found the report (somewhat) ambiguous but it was very informative and well prepared and comprehensive.

Response: Thank you for your comment.

29. I thought the content was not completely factual and its basis was unsubstantial.

    There must be some sort of risk working at a plant where nuclear weapons are disarmed.

    Tell us the truth, bunnies are running around with seven ears!

    The people need to know of every possible concern of plant problems.

    I thought it was a lie-don't waste my time.

    It is a lie! I envy the genius stature of the person(s) who make the people believe such malarchy. Send out a poll in which you really do want to hear from the public. Thanks.

Response: Thank you for taking the time to comment.

30. Overall, the PHA remains characterized by a lack of documentation on methodology and data sources, and confusion over the scope of the assessment. Thedocument also offers weak arguments that cannot be substantiated under close scrutiny.

It is recommended that ATSDR submit this document to a rigorous, independentprofessional review by highly qualified experts outside of the internal Pantex and DOEregulatory and oversight structure.

Response: ATSDR submitted the December 11, 1997 Pantex Plant Public Health Assessment, public comment release, to a panel of external scientists and public healthprofessionals for peer review of the technical data presentation format and determination ofcompliance with ATSDR's public health assessment mandate. The panel consisted entirely ofnon-ATSDR employees and panel members were chosen for their expertise in epidemiology,toxicology, groundwater, and radiation. The independent peer review process was conductedduring January 1998 and the peer reviewers' comments are incorporated in this public healthassessment.

31. Define the meaning of the PHA - ATSDR has focused its message on what it can state about Pantex, much to the exclusion of what it does not know about Pantex. ATSDRshould make perfectly clear what it cannot determine about the effects of past operations,and identify specifically where in the PHA professional judgement was used when hardquantitative evidence was unavailable.

It is improbable that there is enough information to make any conclusive assessment aboutthe effects of past Pantex operations on public health and safety. ATSDR must make thedistinction about what period of the past falls outside of the scope of the PHA due to a lackof information.

ATSDR should make this effort because the primary--and most publicized--conclusionsfrom the PHA include assertions that "the Pantex plant does not pose a threat to publichealth from any site release at this time" and that Pantex "is probably not the cause of thehigher than expected levels of cancer found in the counties surrounding Pantex." (page 1).

This latter statement could easily be interpreted and rewritten, without any loss ofaccuracy, in the following manner: "There is still a possibility that Pantex could be thecause of the higher than expected levels of cancer found in the counties surroundingPantex, but there is insufficient data to determine any relationship."

It is only evident that the incidence of cancer and other adverse health problems in the areacannot be traced by evaluating existing operations at Pantex, yet ATSDR implicitlyexonerates Pantex of all responsibility. A more generalist, objective approach is needed,and ATSDR should be as definitive about what it cannot conclude and what it canconclude. It appears highly probable that the primary conclusions should include thefollowing:

    There is insufficient information to determine whether the incidence of cancer orother adverse health effects in the area are related to past operations at the Pantexplant.

    While the higher than expected rate of cancer and birth defects cannot be linked toPantex operations, Pantex cannot be ruled out either.

    There is not enough information to determine whether there were exposurepathways prior to 1970, and the information between 1970 and 1990 may beinsufficient to determine whether exposure pathways existed during this time. Anyhealth effects from exposures that may have occurred prior to 1990 cannot beaddressed in this document.

    There are enough uncertainties about health issues in the area to warrant further investigation.

Response: Response noted.

32. Petition for declassification of classified documents - Throughout the cold war, secrecy compromised the public' s right to know about the impact of DOE facilities on theircommunities. The cold war is over, and the Department of Energy has madeimprovements in its openness policies and remains committed--at least on paper--tosubstantial public access to previously classified documents. In December 1997 Secretaryof Energy Pena signed a rule that prohibits DOE from classifying information aboutnuclear activities that is solely related to public and worker health and safety orenvironmental quality.''

As a public health agency, ATSDR has an obligation to inform people about past--andpresent-activities that released contaminants to the environment and raised the risk to thepublic. It is not the job of ATSDR or any other government agency to decide what thepublic should know about environmental, safety, and health issues.

ATSDR would fulfill a public service by petitioning the Department of Energy to release allclassified documents that were reviewed during the preparation of the PHA pertaining toPantex operations and that are related to public and worker health and safety or environmental quality.

Response: A review of Pantex Plant classified documents was conducted by the ATSDR Senior Health Physicist during the September 1995 site visit. It was determined that none of theclassified documents related to the scope of the Pantex Plant public health assessment. Documents reviewed in preparation of the Pantex Plant public health assessment pertain to wastemanagement, environmental sampling, and environmental restoration activities. Thosedocuments are not classified.

33. Recognize data limitations - During preparation of the PHA, ATSDR relied heavily upon the use of data provided by the Pantex plant, but provided no indication ofthe validity of the various data sets. This is a serious omission in the PHA, because there isgeneral acknowledgement that pre-1970 environmental monitoring was minimal tononexistent at Pantex, and that the early environmental monitoring program wasinsufficient.

It was during this era that environmental abuses during routine operations were moreprevalent. During this time, Pantex had substantial releases of depleted uranium to theatmostphere from the firing site, and released wastewater on-site and off-site that was soheavily contaminated that eventually the perched layer of water below Pantex was pollutedto levels well above health standards. ATSDR has not offered any evidence in the PHAsuggesting that these past activities did not result in exposure pathways that affectedpeople' s health then and now. The Department of Energy and its predecessors arerenowned for shortcomings in data collection and analyses, and examples of informationgaps at Pantex include:

    Prior to 1989, DOE admits that worker exposure records were seriously flawedbecause internal doses were estimated or not recorded, so the records of DOEnuclear workers who were at risk of internal exposures are "incomplete, misleading,and inaccurate."

    Prior to 1990, Pantex admits that the groundwater monitoring program wascharacterized by a "lack of quality assurance project plans, inadequate samplingprotocols, and inadequate sampling techniques." As a result, groundwater dataprior to this date is useful for "general trending and rudimentary screeningpurposes as an indicator of the historical presence of contaminants of concern."

Response: This public health assessment did not consider exposures to workers. Worker health studies are the purview of the National Institutes of Occupational Safety and Health.

ATSDR does not believe the historical databases are completely invalid because they don't meettoday's standards. Even if there are data gaps, the data we have are numerous and consistentenough that they would require large deviations to move the average values significantly. Noneof our ways of looking at the data (e.g., air concentrations, release quantities, CAP88 modeling,soil concentrations) indicate that there are large inconsistencies in the data. Although not perfect,ATSDR concluded that databases reviewed for the Pantex Plant public health assessment weresufficient and appropriate.

34. According to the PHA (page 19), ATSDR, "selects and discusses contaminants based on several factors: sample design, field and laboratory data quality, and compansonof chemical concentrations to levels that could cause cancer or other health effects." ATSDR states this occurred, but does not provide any insights on the results beyondgeneric assurances. The final PHA should contain an appendix that cites each data sourceused in preparation of the PHA, and that addresses the following factors for each data set:

    Statistical validity in terms of sample size and variance

    Quality of data in terms of validation of tests, quality assurance programs, samplingprotocols, and sampling techniques

    Limitations of data in relation to the nature of operations

    Additional data needs

    The nature of releases and the constraints of monitoring technology in relation to these releases

Response: Approval of Pantex Plant environmental monitoring protocols and quality control programs is the responsibility of the regulatory agencies such as TNRCC and the EPA. ATSDR reviewed the Pantex Plant environmental monitoring program, as approved by TNRCCand EPA and concluded that program is adequate for the purposes of environmental assessment. Appendix B of this document lists the documents we reviewed in reaching that conclusion. Those documents are also available in the Pantex Plant reading rooms.

35. Define limitations of models - ATSDR also relied upon data derived from computational models in preparing the PHA. ATSDR cites the use of the Toxic ChemicalRelease Inventory that requires manufacturing facilities that use or manufacture certain chemicals in amounts "greater than its specified threshold for manufacture, import,processing, or other use...to estimate their annual releases of such toxic chemicals into theair, water, and land."

Pantex estimates potential air emissions from open burning of high explosives at theBurning Grounds using an air dispersion model. Pantex also made estimated doseassessments from airborne releases of tritium in the 1980's, including the 1989 release of40,000 curies of tritium. The PHA authors draw conclusive results from these estimatesWithout any visible analysis of the models used during estimations.

Most of the releases at Pantex are difficult to model because they were, and are,discontinuous, sporadic, and often accidental. If the releases occur in pulses, are themodels equipped to assess this variability? ATSDR should provide an appendix in the finalHealth Assessment that clearly defines the advantages and disadvantages of the models andmethods used in estimating air emissions from the Burning Grounds, Firing Sites, andtritium releases. Also, since ATSDR did address accidental tritium releases, it shouldidentify all accidents that have occurred, including uncontrolled wildfires in the 1990's atPantex.

Response: All models have limitations such as the default values used to define the releases, the release rate variability, the terrain surrounding the release point, the use of standardmeteorological data, standardized risk values, the dispersion (plume) characteristics, to name afew. In many cases errors from the use of the models are not major sources of inaccurate modelpredictions. The documentation included with the CAP88-PC (the users guide) states "Dose andrisk estimates from CAP88-PC are applicable only to low-level chronic exposures, since thehealth effects and dosimetric data are based on low-level chronic intakes. CAP88-PC cannot beused for either short-term or high-level radionuclide intakes." In the case of the Pantex Plant,several limitations previously mentioned are not applicable. For example, the terrain around thefacility is flat thus buildings higher than the release point do not affect the dispersion pattern, theterrain is flat with no hills or valleys affecting the plume, the meteorological information wasbased on historical values, and the low level release continuously occurs from a distinct point;thus the dispersion appears to follow Gaussian characteristics.

36. Correct and clarify - The PHA continues to be troubled by inaccurate, misleading, and/or unsupported statements. ATSDR should make an effort to provide support forthese statements or otherwise delete them from the PHA. The list includes the following:

  1. (Page 23): "If contamination of the Ogallala aquifer were to occur, it wouldbe discovered first in the production wells." ATSDR should support thisstatement.
  2. (Page 25) "To date, instances where contaminant concentrations have exceeded guidelines do not pose a threat to human health." ATSDR shouldqualify this statement by defining the known period of monitoring.
  3. (Page 25) "Since the issuance of the Pantex permits, some metals have been detected at Outfall 6." The EPA issued a ruling of noncompliance in November, 1997 that is not addressed in the surface waters section.
  4. (Page 28) "In addition, a Fourier Transform Infrared (air) monitor was installed in 1995...northeast of the plant." ATSDR should identify whetherthis monitoring station has operated effectively, since TNRCC officials havestated that the data from this station cannot be validated, and that the station has been nonfunctional during long periods of time.
  5. (Page 28) "If an air concentration is above the ESL, it is not indicative that adverse health effects will occur, but rather that further evaluation iswarranted." ATSDR should delete this statement unless it is willing tobalance it by stating that if air concentrations are below the ESL, it is notindicative that adverse health effects will not occur.
  6. (Page 35) "The DU (depleted uranium) information can be misleading if all releases occurred as a result of brief periods of testing at the firing sites." ATSDR should discuss the implications of this possibility on public health tothe same degree it downplays the implications of troublesome trends
  7. .

Response:

(a) The Pantex Plant public health assessment reads, "samples from the production wells are used as a secondary check for possible chemical migration from the perched aquiferinto the Ogallala aquifer. If contamination of the Ogallala aquifer were to occur as a result ofPantex Plant operations, it would be discovered first in the production wells. In this manner, thePantex Plant production wells serve as interceptor wells for the downgradient City of Amarillodrinking water production wells." Because the Pantex Plant production wells are located on-siteand are draw from the Ogallala, any contaminant intrusion from the perched aquifer to theOgallala would be detected first in those wells due to their cone of influence.

(b) The monitoring period discussed is 1973 to 1998

(c) A discussion of the EPA Administrative Order has been added to the Surface Waters Section of this document.

(d) The Fourier Transform Infrared air monitor has been in use since 1995 and was an addition to an existing air monitoring network. In September, 1997, TNRCC contracted withRadian Corporation to operate and maintain that monitor. Since that time, the system has functioned reliably.

(e) Exceeding screening values does not mean that adverse health effects will occur. ATSDR considers what exposure assumptions are appropriate and what is known about thetoxicity of the substance. In this particular exposure scenario, the air concentration did not posea public health threat.

(f) ATSDR considered the impact on public health for the release of DU during burning ground detonations. The following parameters were used in the evaluation. Theburnings occurred during specific meteorological conditions, that is, low winds and a clear sky. This results in the peak downwind concentration near the release point. DU is very dense and itsdownwind migration would be limited. We, therefore, used a modifying factor of 1% reaching adistance of 3,281 feet (1 kilometer) from the burning grounds. ATSDR also performed itscalculations as an instantaneous release at a height of about 100 feet (30 meters). Using graphsof normalized dispersion factors as published in the Health Physics and Radiological HealthHandbook (revised edition), we estimated the downwind concentration of uranium-238 (themajor constituent of DU). We then used the inhalation dose conversion factors as published bythe ICRP to estimate the whole body dose to an adult. This dose was less than 6 millirem -- adose not expected to cause adverse health outcomes.

37. (p.i para 4) "... ATSDR scientists then evaluate whether or not there will be any harmful effects from these exposures."

I am amazed that anyone, short of God, would KNOW this. Don't you REALLY mean thatyou will evaluate whether or not YOU THINK or YOU EXPECT there to be any harmfuleffects from these exposures? This statement is inaccurate and overstates ATSDR ability.

Response: No change. The sentence states that the evaluation is made by ATSDR scientists.

38. (p. 1 para 1) "No site-related contaminants are currently accessible on- or off-site at levels that would cause adverse health effects."

Please identify WHAT the levels for various contaminants to cause adverse health effectshappen to be. Also, please identify which contaminants over what time period and bywhom were "monitoring and surveillance off-site" conducted, prior to your drawing thisconclusion.

Response: ATSDR comparison values are included in the ATSDR database, HAZDAT, which is available to the public on ATSDR's webpage at http://www.atsdr.cdc.gov/.

39. (p. 1 para 2) "...it is unlikely that area residents come into contact with significant enough amounts of chemicals or radioactive substances... "

What about in the past? The levels of contaminants that were encountered by arearesidents in the past do not appear to have been evaluated. For example, the release ofstrontium (used as a tracer during testing) may have resulted in health effects that have notbeen evaluated. There are likely other examples. Exposures due to past activities do notappear to have been evaluated as reported in this document.

Response: The Pantex Plant public health assessment time period is 1973 to present.

40. (p. 6 para 5) "Rainfall averages between 18 and 20 inches/year and pan evaporation about 95 inches/year, so surface evaporation is up to five times greater thanaquifer recharge."

This statement seems to assume that all of the rainfall (and I suspect some of it is actuallysnowfall) ends up in the aquifer. Technically, this statement appears to be inaccurate.

Response: Sentence revised to " Rainfall averages between 18 and 20 inches/year; however, surface evaporation is up to five times greater than precipitation."

41. (p. 7 para 2) "Overall, pumping of the Ogallala aquifer has lowered the static level of the aquifer by about 2 feet/year, and pumpage exceeds recharge by a factor of6."

Even this assumption of 4 inches/year recharge to the Ogallala aquifer is not consistentwith the DOE statement that the Ogallala aquifer is not in danger of receiving any contaminants that are known to be in the soil and perched aquifers.

Response: Based on updated information, the document has been changed to reflect an aquifer recharge rate of less than 1 inch per year and that pumpage exceeds recharge by a factorof 24.

42. (p. 18 para 1) "effects of gaseous tritium releases (the last one recorded in 1989)"

Was the venting of the Cell One (planned release) that took place after 1989 looked at?

Response: Yes

43. (p. 1 8 para 1) "potential contamination of private and municipal wells;"

There was no evidence provided in this document to suggest that you looked at the"potential contamination of private and municipal wells". What wells did you look at?Were synergistic and antagonistic interactions and effects considered?

Response: ATSDR reviewed sampling data for the City of Amarillo municipal wells and Pantex Plant neighbor wells. In reference to ATSDR's consideration of synergistic andantagonistic interactions and effects, ATSDR uses health comparison values such as MinimalRisk Levels (MRLs) developed by ATSDR when they are available or Reference Doses (RfDs)developed by the U.S. Environmental Protection Agency to evaluate the potential for hazardoussubstance exposures to cause noncancerous health effects. ATSDR uses various cancerclassification schemes developed by organizations such as the National Toxicology Program ofthe Department of Health and Human Services, the International Agency for Research on Cancer,and the U.S. Environmental Protection Agency to qualitatively identify cancer threats posed bycancer-causing hazardous substances. To quantitate the cancer risk posed by these substances,ATSDR uses cancer potency factors developed by the U.S. Environmental Protection Agency todevelop theoretical estimates of how many additional cancer cases might be expected to occur ina given population under specific exposure conditions.

The health comparison values described above and the quantitative estimation of cancer risk doin fact consider cumulative exposures. The MRL and RfD values constitute levels that arebelieved to be without appreciable risk over a lifetime of exposure. The safety factors used in thederivation of these values also takes into account the possibility of sensitive populations such asinfants, the elderly, and immunocompromised individuals being present.

44. (p. 19 para 5) "ATSDR reviewed... non-radiological and radiological data...1973 through l995."

No information as to the quality of the data was provided. Some of the analyses were notconducted by the contract laboratories within the established holding times, for instance. No mention was made that ATSDR eliminated such data in determining whether the data on hand were adequate.

Response: The data we have are numerous and consistent enough that they would require large deviations to move the average values significantly. None of our ways of looking at thedata (e.g., air concentrations, release quantities, CAP88 modeling, soil concentrations) indicate that there are large inconsistencies in the data. Although not perfect, ATSDR concludedthat databases reviewed for the Pantex Plant public health assessment were sufficient andappropriate.

45. (p. 23 para 2) "The Pantex Plant Groundwater 78 wells [64 , 5 , 7 , and 1]"

The number of wells (64 + 5 + 7 + 1) adds up to 77 wells. Where is the other well?

Response: 77 is the correct number and the change has been incorporated.

46. (p. 23 para 3) "If contamination of the Ogallala aquifer were to occur..., it would be discovered first in the production wells."

This statement does not consider the opportunity for the contaminated water in theperched aquifers (some of which is off-site) to find its way to the Ogallala off-site. Also, itwould be more convincing if the lateral distances from various locations of the Ogallalathat would be most likely to become contaminated (beneath perched zones, for example)and simple calculations as to various scenarios (if contamination occurred beneath PlayaOne, for example, what length of time from the moment the Ogallala aquifer becamecontaminated would it take for the contamination to reach the nearest or the most likelyproduction well?). This information would be useful to understanding the impact of timeon discovering any problems that may occur.

Response: To model a worst-case scenario where on-site contamination traveled to drinking water wells, the Draft Final 3-Dimensional Site-Wide Groundwater Flow andContaminant Transport Model (March 1997) was used as the primary reference. Travel times forgroundwater flow within the Ogallala aquifer to selected wells were estimated. The locations ofthe wells discussed here are illustrated in Figure 12 located at the end of this appendix. Representative values for hydraulic gradient, hydraulic conductivity, and effective porosity wereobtained from the primary reference.

First, flow from beneath Playa 1 to Well 15-20 and the Vance Well were considered. Both wellsare located approximately 5,000 feet from Playa 1. Using this distance, a gradient of 0.0055, ahydraulic conductivity of 22.5 feet per day, and an effective porosity of 20%, the estimated traveltime for Ogallala groundwater to travel from Playa 1 to either receptor well is 8,065 days or 22 years.

A second calculation estimated travel time of potential contamination from PTX06-1038, nearthe Pantex east gate, to the private wells which are the nearest potential downgradient receptors. Using the same values for hydraulic gradient, hydraulic conductivity, and effective porosity, andan estimated distance of 10,750 feet, the estimated travel time from well PTX06-1038 to theprivate wells is roughly 19,196 days or 52.6 years.

It is important to note that these numbers are estimates of total travel time based upon averagelinear advective groundwater flow velocities, and assume uniform hydraulic gradients andproperties along the flow path. The assumption is that the contaminants move at the same rate asthe groundwater. This does not always occur because the contaminant may chemically interactwith the soil, causing retardation of the contaminant movement. No dispersion, dilution, orretardation is accounted for in these calculations; therefore, these are worst-case estimates basedon maximum rate of travel. These numbers do not represent any known contaminant loading dates or events within the Ogallala aquifer.

47. (p. 23 para 5) "Constituents analyzed... are listed in Appendix A."

This document suggests that these are the constituents that have been analyzed throughoutthe period of time being considered (1975 on?). Such is not the case, and thus, by omittingthis vital information, this community is misled.

Response: Appendix A is a combined list of environmental monitoring parameters for 1992 through 1997. In preparing the Pantex Plant public health assessment, ATSDR reviewed thenon-radiological (chemical) and radiological data collected in support of environmentalmonitoring at the Pantex Plant for the period 1973 through 1997. Those documents are availablein the Pantex Plant reading rooms.

48. (p. 24 para 3) "however, concentrations were below health screening values."

Please explain why ATSDR is unwilling to state what the "health screening values" are inthis instance (and in others throughout this report).

Response: The current ATSDR health comparison values selected for those contaminants related to the comment are 400 ppb for HMX explosive; 30 ppb for RDX explosive; 5 ppb for the1,3,5-TNB and 2,4,6-TNT explosive; 20 ppb for 2,4-DNT explosive; 5 ppb for benzene, 1,2-dichloroethane, methylene chloride and trichloroethane; 300 ppb for tetrachloroethane; 100 ppbfor total chromium; and 50 ppb for hexavalent chromium. It is critical to note that, even if thecontaminants concentrations should exceed those values in the future, a resident would have to be drawing water from that particular perched aquifer for a completed exposurepathway to occur. To date, ATSDR has not been able to identify any residents utilizing thatparticular perched aquifer downgradient of the contaminant plume.

49. (p.25 para 3) "Chemical contamination above screening values has not been detected... "

Again, the screening values have not been identified. How can we evaluate future data asthey are released if you have not taken the opportunity to identify what the levels ofconcern for each constituent happens to be?

Response: The current ATSDR health comparison values selected for those contaminants related to the comment are 400 ppb for HMX explosive; 30 ppb for RDX explosive; 5 ppb for the1,3,5-TNB and 2,4,6-TNT explosive; 20 ppb for 2,4-DNT explosive; 5 ppb for benzene, 1,2-dichloroethane, methylene chloride and trichloroethane; 300 ppb for tetrachloroethane; 100 ppbfor total chromium; and 50 ppb for hexavalent chromium. It is critical to note that, even if thecontaminants concentrations should exceed those values in the future, a resident would have tobe drawing water from that particular perched aquifer for a completed exposure pathway tooccur. To date, ATSDR has not been able to identify any residents utilizing that particularperched aquifer downgradient of the contaminant plume.

50. (p. 27 para 3) "Soil samples are collected from two general landscape positions: playa bottoms..."

The recent nature of these soil samples seems to have been overlooked. Please provide thedates that sampling was begun in order to give a more accurate picture of what the currentknowledge happens to be.

Response: Routine Sampling of the playa bottoms began 17 March, 1994. The document has been amended to add this statement.

51. (p. 29 para 2) "The only ... inorganic fluoride concentrations in vegetation...."

It is my understanding that the State of Texas no longer has established limits. If this iscorrect, do these analyses continue to be conducted?

Response: Neither Texas nor the EPA have current limits for inorganic fluoride concentrations in vegetation in effect; however, Pantex continues to monitor this parameter.

52. (p. 37 para 1) Last sentence has a problem, a missing word?

Response: The sentence has been completed as "levels that adversely effect health".

53. (p. 37 para 2) "Quality Assurance and Quality Control summaries from EPA and DOE ... No analytical problems were noted ..."

Please identify the years to which this statement applies. The way it is stated, it applies tothe ENTIRE period of data covered by this document. If this is not so, it should be stated.If it is so, it should be clarified.

Response: The summaries covered the environmental monitoring data for the entire period of this report (1973-1998).

54. (p. 61 Question 10) Again, a calculation as to the length of time from when a contaminant would enter the Ogallala aquifer to when it would be detected in theproduction wells (based on the known rates of movement of water within the aquifer)would be informative.

Response: To model a worst-case scenario where on-site contamination traveled to drinking water wells, the Draft Final 3-Dimensional Site-Wide Groundwater Flow andContaminant Transport Model (March 1997) was used as the primary reference. Travel times forgroundwater flow within the Ogallala aquifer to selected wells were estimated. The locations ofthe wells discussed here are illustrated in Figure 12 located at the end of this appendix. Representative values for hydraulic gradient, hydraulic conductivity, and effective porosity wereobtained from the primary reference.

First, flow from beneath Playa 1 to Well 15-20 and the Vance Well were considered. Both wellsare located approximately 5,000 feet from Playa 1. Using this distance, a gradient of 0.0055, ahydraulic conductivity of 22.5 feet per day, and an effective porosity of 20%, the estimated traveltime for Ogallala groundwater to travel from Playa 1 to either receptor well is 8,065 days or 22 years.

A second calculation estimated travel time of potential contamination from PTX06-1038, nearthe Pantex east gate, to the private wells which are the nearest potential downgradient receptors. Using the same values for hydraulic gradient, hydraulic conductivity, and effective porosity, andan estimated distance of 10,750 feet, the estimated travel time from well PTX06-1038 to theprivate wells is roughly 19,196 days or 52.6 years.

It is important to note that these numbers are estimates of total travel time based upon averagelinear advective groundwater flow velocities, and assume uniform hydraulic gradients andproperties along the flow path. The assumption is that the contaminants move at the same rate asthe groundwater. This does not always occur because the contaminant may chemically interactwith the soil, causing retardation of the contaminant movement. No dispersion, dilution, orretardation is accounted for in these calculations; therefore, these are worst-case estimates basedon maximum rate of travel. These numbers do not represent any known contaminant loadingdates or events within the Ogallala aquifer.

55. (p. 71 Appendix A) This list of monitored parameters does NOT apply to the entire period included in this report. Providing this information in this manner ismisleading to the community. A more useful tool would be to provide the periodicity ofmonitoring for EACH of the parameters listed. Then, we might feel somewhat reassuredthat ATSDR looked in detail at the data for the entire period of time included in thisreport.

Response: Appendix A is a combined list of environmental monitoring parameters for 1992 through 1997. In preparing the Pantex Plant public health assessment, ATSDR reviewed thenon-radiological (chemical) and radiological data collected in support of environmentalmonitoring at the Pantex Plant for the period 1973 through 1998. Those documents are availablein the Pantex Plant reading rooms.

56. (p. 82 Appendix B) Several documents were listed more than once in the review listing: 19 and 33; 23 and 50; and 8, 9, 10 and 57, 58, 59 are some examples of theduplication.

Response: That duplication has been corrected in this document and the references reformatted.

57. (p. 87 Appendix C para 6) "... more than 11,000,000 gallons ... treated."

Please provide a comparative volume that will REQUIRE treating. When will the feat beaccomplished? What IS the area of influence of this treatment?

Response: The calculations presented are for the perched aquifer described in this document and located in the southeast corner of the Pantex Plant. The volume of RDX-contaminated water at a concentration above 1 ppb is roughly 1.20 billion gallons. The volumeof chromium-contaminated water at a concentration above 100 ppb is roughly 1.15 billiongallons. There is some overlap between the two contaminant plumes, and the total volume ofcontaminated groundwater would be much less than the 2.35 billion gallon total that you wouldget by adding the two volumes together. An estimate of about 1.5 billion gallons would bereasonable for the total volume of contaminated groundwater. The process is designed as aninterception technique to prevent further plume migration and to ultimately reduce contaminantconcentrations; there is no set schedule for project completion. The area of influence is thecontaminated perched aquifer.

58. (p. 87 Appendix C para 6) "The treatability system is 100% effective..."

There is absolutely NO scientific basis for this statement! The most that you can possiblystate is that the amount that we currently are technically able to MEASURE has beenremoved (and only if proper analytical methods have confirmed even this statement). And,the detection levels (again) are not identified in this paragraph.

Response: The statement has been amended to read "The treatability system is effective in that treated water contaminant concentrations (explosives and total hexavalent chromium) arebelow detection limits. The detection limit for explosives is 1 ppb, total chromium is 5 ppb, andhexavalent chromium is 10 ppb."

59. (p. 90 Item 6 para 2) "... which reduces the explosives... to below drinking water standards."

Again, no attempt was made to identify WHAT those STANDARDS happen to be.

Response: In this particular environmental scenario, the appropriate ATSDR drinking water standards for the contaminants of concern are 400 ppb for HMX explosive, 30 ppb forRDX explosive, 5 ppb for TNT explosive, 100 ppb for total chromium, and 50 ppb forhexavalent chromium.

60. (p. 91 Item 8 para 1) " Plant site rainfall and runoff ... flow to four on-site playas."'

This contradicts statements made earlier in the document. See p. 6 para 5.

Response: Page 15, first full paragraph, has been changed to " All surface drainage flows into these playas, of which 4 are located within the DOE-owned Pantex Plant boundaries".

61. What about the claim that each of the persons that irrigated from the pipeline to Pantex Lake have gotten cancer and died? Is this an accurate statement? And if so, whatis ATSDR's logical explanation for this seeming anomaly?

Response: ATSDR was unable to locate that population through local inquiries, contact with the Pantex Plant Citizens' Advisory Board, and public meetings. Therefore ATSDR wasunable substantiate the claim.

62. ATSDR fails to properly define dose levels considered a public health hazard and misrepresents the meaning of ICRP dose limits - The ATSDR makes several assertions to exposure levels considered to be a public health hazard:

In the introduction of Section IV (Environmental Contamination and other Hazards), the ATSDR report states on page 19 that contaminant concentrations detectedon- and off-site are compared to values that are believed to be without adverse healtheffects upon exposure. The following set of reference values were used in Section IV.C.4(page 29):

Derived Concentration Guides (DCG): continuous exposure over one year would result inan effective dose equivalent of 100 mrem

    Maximum Contaminant Levels (MCL): Regulatory limit for contaminants indrinking water supplies (equivalent to doses of 4 mrem/yr)

    Radiation Concentration Guides (RCG): Doses from concentrations inenvironmental media below RCG values would not exceed 170 mrem.

In the review of environmental data, all of above levels were used even though they clearlyrepresent different dose levels.

The basis for the Derived Concentration Guides are recommendations by the InternationalCommission on Radiological Protection (ICRP). The ICRP recommends a limit of 100mrem/yr from sources other than medical and those occurring naturally in theenvironment (up to 500 mrem/yr if 5 year average does not exceed 100 mrem/yr). It shouldbe noted that the ICRP reports do not contain a claim that doses below the limit for thegeneral public would not result in adverse health effects. The 1990 Recommendations ofthe ICRP (ICRP Publication 60) state that "it must be presumed that even small radiationdoses may produce some deleterious health effects" (p.35) and "stochastic effects cannot becompletely avoided because no threshold can be invoked for them" (p.25). ICRP furtherdefines its philosophy of setting individual dose limits as follows: "It is the Commission'sintention to choose values of dose limits so that any continued exposure just above the doselimits would result in additional risks from the defined practices that could be reasonablybe described as "unacceptable" in normal circumstances. Thus the definition and choice ofdose limits involve social judgements. These judgements are difficult, partly because thedose limit has to be set at a defined value and there is no discontinuity in the scale ofacceptability. For agents like ionizing radiation, for which no threshold can be assumed inthe dose-response relationship for some of the consequences of exposure, this difficulty isinescapable and the choice of limits cannot be based on health considerations alone. " (p.30f.)

ATSDR does not define "levels above which observed adverse health effect levels" in thediscussion of tritium releases on p.36. It is stated that an individual would have to consumeover 5,000 tons of affected vegetation per year to approach a dose with potential adversehealth effects. The reference to a calculation assuming an annual ingestion of 5,000 tons ofvegetation is referred to again in the section entitled "Pathway analysis" (p.38) and the"Conclusion" (p.63). No details are provided as to which level of tritium in the vegetationwas assumed and which dose was actually calculated.

One way to infer this information is to use the largest dose to a member of the public fromtritium releases at Pantex which according to ATSDR was 1.43 mrem in 1989 (Table 2, p.36). ATSDR attributes the doses due to releases of tritium mainly to ingestion of fruitsand nonleafy vegetables. The typical consumption of fruits and non-leafy vegetables by anindividual is in the order of 100 kg per year. Thus, the same individual receiving a dose of1.43 mrem per year from the average consumption of fruits and vegetables would receive adose of ~70 rem per year if he or she ingests the (hypothetical amount of) 5,000 tons peryear of vegetation. Such a dose far exceeds the ICRP limit of 0.1 rem per year which wasused by ATSDR as one of several reference values "that are believed to be without adversehealth effects upon exposure".

In summary, the ATSDR report fails to properly define "values that are believed to bewithout adverse health effects upon exposure." ATSDR furthermore misrepresents themeaning of implied dose limits by asserting that doses below such limits are associated withno adverse health effects even though the ICRP finds that no threshold can be invoked forstochastic effects such as cancer. ATSDR' s example that the consumption of 5,000 tons peryear of tritium contaminated vegetation from the Pantex vicinity would not cause adversehealth effects is unsubstantiated and likely to be in error.

Response: Although there have been 100's and perhaps 1000's of studies on low radiation doses from environmental radiation sources or exposures from other types of radiation sources,no adverse health effects have been conclusively shown to exist. In the case of occupationalexposure to radiation over a long term, evidence is beginning to surface that a dose of 2 to 5 remmay result in leukemia or other blood related cancers. Exposure to high levels of radiation notfound in the environment can lead to deleterious health effects. However, these exposures occurat doses in excess of 10 rem delivered over a short period of time, such as days. Symptoms ofthese levels of exposure include the classic responses such as hair loss and decreased red bloodcell numbers at the doses of 25 to 50 rem.

Regarding the intake of potentially contaminated food stuff, ATSDR has recalculated the values. Using the dose limit of 1 mSv (100 millirem), the amount of fruits and vegetables that wouldneed to be consumed would be 7,500 kilograms or 8.25 tons of food per year. The value in themain text is the amount for documented adverse health effects resulting from exposure toradiation.

63. ATSDR drew far-reaching conclusions from an incomplete set of data - On page 63, the ATSDR report contains the claim that "[o]ff-site radiation exposures to the publicliving next to the Pantex Plant are well below levels that would cause adverse healtheffects" (note the present tense). The major source for this far-reaching conclusion is thedata contained in the environmental monitoring reports. The monitoring system in placearound Pantex was initiated in 1972 and, in ATSDR's own words "[a]t that time (...) contained a limited amount of data" (p.32).

The Atomic Energy Commission (AEC) chose the Pantex site for the expansion of itsnuclear weapons assembly facilities in 1951. No information was reviewed by ATSDR forthe 22 years from 1951 up and including 1971 before environmental monitoring wasinitiated in 1972. ATSDR did not comment on potential exposures prior to 1972 and theirimpact on the health of local residents. This omission is especially serious since it is nowreasonably well established that radioactivity releases from nuclear weapons plants weretypically far higher in the 1950s and 1960s than in subsequent years.

Response: Although the Pantex plant is considered a nuclear weapons plant, its operations are not comparable to weapons plants such as Hanford, Oak Ridge, or Savannah River. Theseare materials production centers, not final weapons fabrication (assembly, disassembly, andquality assurance testing) facilities. The nature of the operations at Pantex are much differentthan the production centers. The Pantex releases to the environment, in ATSDR's opinion, havenot impacted the environment to the same extent as the materials production centers. We believethis comment is without basis.

64. ATSDR analyzed available environmental data in an inappropriate fashion - ATSDR summarizes doses to the public resulting from tritium releases on p.36. Thelargest release of 40,000 Ci occurred in 1989 and is identified as an accidental release. The"estimated dose to the public" is calculated to be 1.43 mrem. The calculation assumed auniform release during the year. If the same amount of radioactive material is emitted overa short time period rather than evenly distributed over an entire year, the doses to themaximally exposed individual would be expected to be significantly larger. Of course, asmaller number of people would be affected by the release. It is clearly inappropriate toignore the possibility that some individuals received a much larger dose than the onecalculated assuming the uniform release.

In summary, the ATSDR report fails to provide a clear definition as to the level ofradiation exposure associated with adverse health effects even though the claim is madethat no adverse health effects are to be expected. ATSDR's claim that the consumption of5,000 tons per year of tritium contaminated vegetation from the Pantex vicinity would notcause adverse health effects is unsubstantiated and likely to be in error. The report fails toaddress the lack of environmental data for 22 years of Pantex Plant operation. Data usedin the assessment of tritium exposures was improperly interpreted. We recommendrejecting the ATSDR report because its major conclusions regarding the public healthsituation around the Pantex Plant are based on inappropriate methods and the selective useof data.

Response: The comment is comparing two different aspects of the dosimetry question. Bioassay data of the exposed workers indicated that the maximally exposed individual received1.3 rem, and there was a total of 1.5 man-rem for all monitored individuals. Man-rem is the sumof exposures to all the monitored workers; therefore with a total exposure of 1.5 man-rem withone individual receiving 1.3 of that total exposure, the remainder of the monitored workerscollectively received less than 200 millirem. To put the exposures in perspective, the maximumallowable annual exposure dose for monitored workers is 5 rem. The dose estimate at the PantexPlant boundary for the incident was less than 1 millirem. The tritium released in the gravelcovered containment facility has been slowly diffusing from the facility since the day of theaccident. It is this slow leak rate on which ATSDR based its dose calculations - not theimmediate release. The slow leakage has reached the off-site public areas, not the 40,000 Ci.

65. Is the Pantex Plant the only place in the state where the outdated practice of open burning is permitted?

Response: Open burning is currently considered a safe and effective means of high expolosive disposal, and is a common method employed throughout the U.S. by bothgovernment and private organizations. Five other sites in Texas are permitted for open burning ofhigh explosives as a means of disposal. Lone Star Army Ammunition Plant and Red River ArmyDepot in Bowie County, Fort Hood in Coryell County, and Camp Bullis in Bexar County areDepartment of Defense facilities. The GOEX Plant, a private operation in Johnson County, ispermitted to dispose of high explosives used in oil drilling applications.




Figure 12: Well Locations (15-20, Vance, and PT06-1038)



Next Section          Table of Contents

 
 
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

A-Z Index

  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #