PUBLIC HEALTH ASSESSMENT
CORNHUSKER ARMY AMMUNITION PLANT
GRAND ISLAND, HALL COUNTY, NEBRASKA
1980 Total Population: 1,569,825
Percent Black: 3.1%
Percent Spanish Origin: 1.8%
Percent less than 18 years old: 28.5%
Percent greater than 6 years old: 13.1%
1990 Total Population: 1,578,385
1980 Total Population: 47,690
Percent Black: 0.3%
Percent Spanish Origin: 2.8%
Percent less than 18 years old: 30.1%
Percent Greater than 6 years old: 12.5%
1990 Total Population: 48,925
1980 Total Population: 33,180
Pecent White: 97.8% (32,457 persons)
Percent Black: 0.3% (102 persons)
Percent Spanish Origin: 3.2% (1,066 persons)
Percent less than 18 years old: 27.8%
Percent greater than 6 years old: 14.5%
1980 Population by Age Groups:
Less than 5 years: 2,664
5 to 9 years: 2,539
10 to 14 years: 2,428
15 to 19 years: 2,670
20 to 24 years: 3,130
25 to 29 years: 2,960
30 to 34 years: 2,548
3 to 39 years: 1,750
40 to 44 years: 1,420
45 to 49 years: 1,437
50 to 54 years: 1,640
55 to 59 years: 1,665
60 to 64 years: 1,511
Greater than 64 years: 4,818
1990 Total Population: 39,386
Grand Island Employment and Income:
1980 Occupations of Employed Persons:
Employed persons 16 years and over: 16,138
Managerial & Professional 3,449
Technical, Sales, & Administrative Support: 4,797
Service Occupations: 2,620
Farming, Forestry, & Fishing: 248
Precision Production, Craft, & Repair: 2,205
Operators, Fabricators, & Laborers: 2,819
1980 Persons with Work Disability:
Males aged 16 to 64 years: 9,674
Number with Work Disability: 885
Females aged 16 to 64 years: 10,350
Number with Work Disability: 749
1980 Income in Grand Island:
Per Capita Income for Individuals: $7,291
Percent below Poverty Level: 6.9%
|Capital/Le Heights*||Grand Island||Hall County|
|% Asian/Pacific Islander||1.0||1.3||1.1|
|% Other races||0.5||2.7||2.3|
|% Under age 10||17.5||15.9||15.9|
|% Age 6 and older||4.9||14.6||14.2|
|Persons per household||3.10||2.51||2.56|
|% Households owner-occupied||84.9||60.8||63.6|
|% Households renter-occupied||15.1||39.2||36.4|
|Median value, owner-occupied households, $||~60,000||47,600||48,200|
|Median rent paid, renter-occupied households, $||~300||256||253|
** A household is defined as an occupied housing unit.
|Nebraska||Hall County||Grand Island|
|1989 Birth Rate/1000pop||15.0||15.6||15.9|
|Rate of Low Birth Weight (<200 gms) / 1000 live births||58.0||63.4|
|Rate of Very Low Birth Weight (<100 gms) per 1000 live births||10.0||5.2|
# with Birth Defects
Percent of All Births
| 642 |
| 15 |
|Nebraska||Hall County||Grand Island|
1989 Crude Rate
| 14,776 |
| 458 |
| 388 |
1989 Infant Deaths
Rate/1000 live births
| 192 |
| 7 |
| 6 |
1989 Neonatal Deaths
Rate/1000 live births
| 108 |
| 2 |
| 2 |
|Cause||Nebraska||Hall County||Grand Island|
Rates are age adjusted per 100,000 population
|Cause||Nebraska||Hall County||Grand Island|
Rates are Age-adjusted per 100,000 population
|Number||Crude Rate||Number||Crude Rate|
|Lip, Oral Cavity||152||0.1||6||0.1|
|Unspec Female Gen||21||0|
|Unspec Lymph Node||197||0.1||3||0.06|
* Crude Rates per 1000 population
The following responses were received during the public comment period. This list of comments doesnot include editorial comments concerning word spellings, sentence syntax, etc. It does not includecomments on accuracy of stated facts. If the accuracy of a statement was questioned, the statement wasverified or corrected. The portions of the comments below that are in parentheses were paraphrased byATSDR for brevity or clarity. If the same comments were received from more than one source, onlyone comment and response is listed.
Comment 1: The value of child body weight 10 Kg was used in Table 3 concerning soil contamination. According to EPA standard default exposure factors, child body weight should be 15 Kg for age 0 to6 year group.
Response to Comment 1: ATSDR uses 10 Kg as a child body weight to calculate comparisonvalues. Using this lower weight results in a more conservative comparison value for protection of public health.
Comment 2: Page 16, Paragraph 2. The paragraph is very biased. Grab samples are appropriate whenused in conjunction with aerial photography, ground truthing, surveying of discharge pipes and wastewater. Many of the grabs were taken at key locations that would provide the worst case contamination,such as discharge ditches. If contamination is found in the ditch then further areal delineation wouldoccur.
Response to Comment 2: The first sentence of the section on page 15 states: The stated purposeof previous sampling, including samples taken in Fall 1990, was not to define the extent ofcontamination, but to delineate areas requiring further study (1). The paragraph on samplingis presented to simply describe different types of sampling that have occurred. The nextparagraph describes the approach that will follow after the initial sampling. That samplingprovides more extensive determinations of contamination and uses the earlier sampling as a starting point.
Comment 3: The various target excavation levels were set for the explosives. The reference should alsobe provided on these target levels.
Response to Comment 3: The reference was listed later in the paragraph. It has now been added after the sentence in question.
Comment 4: Lead contamination has been found in the North Magazine Area. Consider furthersampling to detect lead contamination in on-post soil.
Response to Comment 4: The phase one field-screening analysis will include 2,4,6 TNT,cadmium, chromium, and lead. This is mentioned in the Proposed Analytes During RI/FS section on page 18.
Comment 5: Pages 18, 19, and 48. At this point in time it is not technically feasible to analyze samplesfor many of the breakdown products of TNT and RDX. This is due primarily to the fact that most ofthose analytes can only be detected by laboratory research methods which are not yet commerciallyavailable. In those cases where the products will be detected via the commercial methods, the productconcentrations will be reported by the Army. For example, the TNT breakdown products 2,4,6-trinitrobenzaldehyde, 3,5-dinitroaniline, and 4,6-dinitrobenzoic acid can and will be reported astentatively identified compounds if their concentration is at least 10% higher than the equipmentcalibration standards.
There are other compounds that can be detected commercially by specific laboratories, but whichweren't included in the workplans submitted for ATSDR review prior to field work. Examples wouldinclude hydrazine, formaldehyde, methanol, and tetranitromethane. However the need for such testingmust be identified prior to the implementation of field work so that the appropriate samplingpreservation, and laboratory arrangements can be made. If ATSDR has some reason to believe thesecompounds may pose a potentially significant health threat at the site, we can attempt to ensure thatthese compounds are addressed in the next phase of the investigation. Sampling for many of the TNTand RDX breakdown products can only be accomplished at significant expense and effort, and withquestionable results. In that light, we do have questions regarding how any information which mightbe obtained by sampling for TNT and RDX breakdown products will be evaluated. Based on ourunderstanding, there is no current health effects information which exists on those breakdown products. If ATSDR is aware of such information, we would appreciate being informed of such so that we cantake that information into account during our evaluation of future workplans for this and other sites.
Response to Comment 5: Choosing specific chemicals to add to an analyte list based onpotential health effects is difficult when little toxicological information is available. Littleinformation is available about health effects of long term exposure to low concentrations of eventhe primary compounds. Additionally, predictions are difficult to make about relativeconcentrations of the breakdown products possibly remaining in the groundwater. Because, ingeneral, health effects to various compounds are related to some extent to concentrations, it maybe of value to obtain information about the relative amounts of some of the breakdown productsin the groundwater. As mentioned in Comment 5, several of the chemicals not listed on theproposed analyte list will be detected during the routine analysis if their concentrations aresignificant. That information has been added to the text of the public health assessment. Of theremaining chemicals that can be analyzed for commercially but were not proposed for analysis,consideration should be given to sampling for hydrazine and 1,1-dimethylnitrosamine.Literature is available on the possible adverse health effects of these compounds. Referenceshave been added to the text of the public health assessment.
Defining the extent of contamination of groundwater with specific chemicals will be of valuein designing health studies to determine whether or not adverse health effects have occurred inthe population because of past exposure to the contaminants. The most important aspects of theinvestigations occuring at CAAP for the protection of public health are activities aimed atidentifying the potential for exposure to contaminants in drinking water and prevention of thatexposure. That process is being carried out in ongoing RI/FS investigations.
Comment 6: Page 22, Paragraph 2, Subsection 4. It should be noted that the reason well constructiondata is not available is that the high number of wells that the Army has been monitoring are domesticirrigation and drinking water wells. These wells were not installed by the Army and the constructiondata is not normally retained by the owner.
Response to Comment 6: This has been added.
Comment 7: The ATSDR defines the completed exposure pathways as a situation in which fiveelements must be present to provide evidence that exposure to a contaminant has occurred, is occurring,or will occur. A potential pathway is defined as a situation in which at least one of the five elements ismissing, but could exist. All potential pathways presented in Table 9 on page 34 are not missing anyof the five elements. In addition, the on-site surface soil pathway could also be a completed pathwaybecause exposure to a contaminant soil has occurred, is occurring, or will occur.
Response to Comment 7. The most important completed pathway of public health interest atCAAP is the private well pathway described in Table 8. Sampling of private wells indicatedthe presence of contaminants in drinking water. Exposure through the route of ingestion mayhave occurred for several years. Current environmental data also indicates the presence ofcontaminants in groundwater. Some people currently are using private wells, and as thecontaminated plume extends, the exposure pathway would also be complete.
Table 9 lists potential pathways. For an ATSDR exposure pathway to be considered complete,information must be available for each of the five elements of the pathway. Substantialenvironmental information is not available for Sediment, Ambient Air and Food Chainpathways. Although some sampling information is available for sediment, additional data isneeded to substantiate the extent of contamination, especially off post in areas where peoplemight be exposed. No sampling data was available for ambient air. In addition, no informationwas available about the relation between the past open burning and the location of the nearestresidences at that time. Limited sampling was available for vegetables in the food chainpathway, however no contamination was found. On-Site Surface Soil is considered presentlyas a potential pathway. Some sampling data is available from many different sites on theinstallation. If CAAP were an active installation with workers and visitors entering theinstallation daily, some of the sites might be considered as sources for complete exposurepathways. However, due to the isolated status of the installation, people do not come in contactwith the contaminated soil for extended (if any) time periods to substantiate a completedexposure pathway. Presently the exposed population element of the pathway is missing. On theother hand, the soils represent a very important potential pathway. Further investigation isongoing in the RI/FS. This additional information must be considered with respect to the futureland use of the CAAP. If changes in activities such as commercial or residential use of the landare proposed, then the potential for public health concern will increase. ATSDR will reevaluatethe information with regard to soil pathways at that time.
Comment 8: "Recommendations" Number 1, regarding public access to magazines would requireHeadquarters, U.S. Army Armament, Munitions and Chemical Command (AMCCOM) to providephysical security support, since the Plant does not have gate guards or patrols during business hours.
Response to Comment 8: Because of the potential for ingestion of contaminated soil, ATSDRrecommends limiting the public's access (especially children) to the areas (magazine) until theextent of contamination is further characterized during the RI/FS. Limiting access to childrencan be performed by a variety of means. If people were reminded to not bring children to thearea, most would comply and thus access of children would be limited. Furthermore, the Army is continuing to reduce the number of storage magazines that are leased for public use.
Comment 9: "Recommendations" Number 2, second paragraph; soil contamination concentration willimpact the extensive leasing of agricultural land on CAAP. Any changes in leases would require acareful approach by the Army, due to the legal, economic and public relations factors involved.
Comment 10: The discontinuance of on-site crop irrigation would have a severe impact on agriculturalleases.
Response to Comments 9 and 10: Recommendation number 2 in the second paragraph isdirected at further evaluation of contamination levels in soils at specific sites where people maybe exposed if the land use changes. If new public use of lands were proposed, further evaluationwould be necessary. This does not refer to major changes in agricultural land use. CAAP hasrecently discontinued agricultural leases in areas of suspected high explosives contaminationof the soil. Other areas, however may be using irrigation water that has high levels ofexplosives. Studies as part of the RI/FS are underway to evaluate the potential of theseconcentrations of explosives to be incorporated into the crops. In addition, use of irrigationwater in 1992 has been low. This also reduces the potential of contaminant uptake by crops. Because the use of irrigation water has been low, crop uptake studies have been postponed tofacilitate a study that will allow a more valid estimate of contamination uptake by cropsirrigated with contaminated water. These studies will also bear on the questions of private well water usage for vegetable gardens.
Comment 11: Since residential gardens, as well as soil from yards (may have been) irrigated with RDXand TNT-contaminated water, vegetable sampling from the gardens should also be tested for TNT. Although no RDX was found in concentrations greater than the detection limits of the assays, TNT maybe found above the detection limit. Plants may uptake more TNT than RDX from soil and irrigatedwater.
Comment 12: The level of 0.19 ppm in vegetables was developed as the health risk level by using EPAguidances. Is this level for RDX only in the vegetables? Are there any health risk levels of otherexplosives in the vegetables?
Response to Comments 11 and 12: Measurement of RDX and TNT in plant tissues is not aroutine, commercially available laboratory assay. To simplify the evaluation, as well as tospeed the initial sampling in vegetable gardens, RDX was used as the indicator contaminant. This choice is supported by the fact that, in general, TNT levels in the groundwater were lowerthan those of RDX, and that laboratory plant studies showed that TNT was more likely toremain in the roots of the plants that was RDX. RDX was also shown more likely to remainintact and not be metabolically broken down as much as TNT (see references 22 and 23).
Comment 13: The detection limits of RDX, TNT, and HMX concentrations in soil were presented inthis section (section B, page 20). Are these limits background levels? Was EPA guidance used todevelop these detected limits?
Response to Comment 13: The referenced detection limits are those for EPA approvedmethodologies for measuring those contaminants in soil. The detection limits are belowATSDR comparison levels used to determine concentrations of contaminants that may causeadverse health effects.
Comment 14: Page 24, Paragraph 2. The discussion of the regional nitrate levels did not reference thedocument "Nitrogen and Irrigation Management, Hall County Water Quality Special Report", datedFebruary 1984. This report summarized that 67-79 percent of the Hall County wells exceeded 10 ppm for nitrates, which would seem to support the regional nitrate concerns.
Response to Comment 14: The report has been reviewed and included in the discussion.
Comment 15: No references were made (page 2, page 20, page 31, and page 46) to the report entitled"Calculation of TNT and RDX Concentration Limits for Feedlot Water Supplies" dated August 1984. The recommendation that the feedlot use city water should not be based solely on the idea that city wateris available and adjacent to the feedlots.
Response to Comment 15: The feedlot study was discussed and referenced in the public healthassessment in the Public Health concerns section. That study is an article written to calculateTNT and RDX concentration limits for feedlot water supplies. It uses risk assessment methodsto determine safe water contaminant levels for the health of the cattle as well as to estimate safewater contaminant levels that would not result in accumulation of TNT and RDX in meat of thecattle. To make calculations of that type, assumptions must be made. Some assumptions mustestimate mathematical safety factors to be included which account for differences in durationof exposure, the species of animal for which experimental data exists, physiologic processes ofcontaminant concentrations in different animal tissues and others. Most of the biological datafrom which these assumptions are made come from a minimum number of studies in animalspecies other than cattle. Thus, the necessary assumptions have room for error.
Calculations using those studies do indeed suggest that TNT and RDX are not likely toaccumulate in meat of cattle (drinking concentrations of explosives found in the groundwateraround CAAP) to the extent that adverse health effects in humans consuming that meat wouldresult. Because of the previously mentioned assumptions that must be made to makeconclusions based on such calculations, other ways to confirm the safety of meat forconsumption may be more reliable. The recommendation was made to use the city water supplyfor watering cattle until suitable animal studies (sampling of feedlot cattle or other experimentalcattle studies) could be carried out to answer the questions. This conservative approach willgive direct information to be certain that explosives are not detectable at concentrations of concern in meat consumed by the public.
Comment 16: We moved out in the afflicted area 6 years ago when the cleanup was all taken care of. We have had our water checked numerous times and for some unknown reason they tell us everythingis fine. I question the validity of the Army and the testing facility. I know that they are drilling new testsites around our area which leads me to believe that there is more to the story than we are being told.
Response to Comment 16: The initial cleanup of CAAP included removal of explosives-contaminated soil that was a source for contamination of groundwater. Further sampling ofboth soil and groundwater is being carried out during the current Remedial Investigation phaseof the work at CAAP. This includes drilling new monitoring wells in the area to determine thewidth and depth of the contaminated area in the groundwater. This will lead to a decision aboutthe best means to clean up the contamination. All testing during the investigation is performedunder specific laboratory criteria. Laboratory results are reviewed by both the Army and EPAto ensure that the analyses were performed properly. As an independent agency, ATSDR alsoreviews laboratory quality control information during preparation of public health assessments.
Comment 17: I question why there has not been a health study on humans, animals and plants. Wehear that there are going to be things done but that is as far as it goes.
Response to Comment 17: Design of a health study that will address potential health effectsresulting from exposure to contaminants in the groundwater around CAAP requires informationabout potential routes of exposure of the population to the contaminants. Continuinggroundwater sampling studies are defining the extent of groundwater contamination. Inaddition, sampling studies have been carried out on vegetables from gardens watered withcontaminated water. No contaminants were found. That represented a possible point ofexposure to people.
The ATSDR Division of Health Studies will perform health studies in the communitysurrounding CAAP. This is listed under Actions Planned in the Public Health Actions sectionof this public health assessment. A preliminary site visit for planning purposes to the area is scheduled for October, 1992.
Comment 18: I have concerns about our livestock, our water tanks have a red oily film when they setfor a few days and inside our house we have had a lot of problems with our well, hot water heater, watersoftener, reversed osmosis system and dishwasher which are all related to water.
Response to Comment 18: The physical appearance of water can be related to a number ofdifferent causes. It can be influenced by bacterial, mineral or chemical contents. The only wayto assess the potential chemical content of water is to analyze the water for specific chemicals.