PUBLIC HEALTH ASSESSMENT
ROCKY MOUNTAIN ARSENAL
ADAMS COUNTY, COLORADO
- Given the Onpost land use controls, visitor access restrictions, Interim Response Actions(IRAs), groundwater intercept and treatment systems (BCSs), and the selected finalremedy documented in the Onpost ROD, the RMA Onpost area is for the present andfuture considered to be a No Apparent Public Health Hazard. The detailed mosaic ofmitigation provided by the land use and visitors restrictions, IRAs, and BCSs haseliminated many possible Onpost and Offpost pathways of human exposure to RMAcontaminants. The provisions of the Onpost ROD coupled with the existing institutionalcontrols and regulations will ensure that the final site remediation activities will becarried out in such a fashion as to minimize or eliminate exposures of public healthconcern.
ATSDR has reviewed the USFWS Health and Safety Plan for Wildlife Area visitors,workers, and remediation personnel and concluded that provisions of that plan areprotective of public health. Surface soil data reviewed to date show that no harm willcome to those visitors who, prior to the completion of the final site cleanup measures, goon the guided tours or who do not stray off designated tour routes or out of the areasdeemed safe for RMA visitors (referred to as "the white areas"). Appendix A has anexplanation of ATSDR's Public Health Hazard Conclusion Categories.
- Because people residing in the Offpost Study Area to the north and northwest experienced past exposures to RMA contaminants via groundwater and air, the area may be considered a Public Health Hazard in the past. However, the frequency, magnitude, and duration of those past exposures is unknown. Many public health concerns have been expressed about the possible effects of RMA remediation and about specific health conditions and diseases, including cancer. Past exposure to the groundwater contaminants in off-post private wells has not been directly associated with the types of cancers or health conditions in question. Many health studies and investigations have been conducted because of community health concerns and past exposures from RMA. To date, those studies and investigations have been inconclusive.
- Off-post private wells to the west of RMA in the EPA Study Area (OU 2), including wells used by businesses, are considered to be an Indeterminate Public Health Hazard. A past and present pathway of human exposure to four different solvents exists for individuals who work or reside in the EPA Study Area of Commerce City and have continued to use their private Alluvial Aquifer wells (see Table 7) rather than be connected to the South Adams County Water and Sanitation Department (SACWSD) municipal water offered to them. The contaminants are emanating from several sources in addition to RMA. The data on the wells were collected between 1987 and 1989; the current concentrations in the wells are not known. If those wells are still in use they are of concern even though the well owners have refused to discontinue their use.
- Data gathered on the foodchain pathway associated with the use of the Offpost irrigation wells indicates that consumption of garden vegetables grown in the Offpost Study Area is No Apparent Public Health Hazard.
- Based upon the data reviewed for this assessment, there are 9 Offpost Study Area private wells that contain levels of lead that are of public health concern, and they are considered to be a Public Health Hazard. The lead in the water may be from several sources, such as naturally occurring lead in groundwater or lead contamination in plumbing.
- Lead was detected at a range of 65.2 ppb to 119 ppb in the water of private wellsnumbered 372A, 540A, 550A, 551A, 578A, 602A, and 603A (see Table 13). Bottledwater is provided, at present, to the residents using these wells, so it is presumed thatthose wells are not used as a drinking water supply. According to TCHD, water from thewells is used mainly for activities such as bathing, showering, and cooking. Non-cancerous health effects are not expected to result from the use of water from those wellsfor showering, bathing, mopping, or other such household uses. However, cooking withand/or drinking water from the wells (including infant formula made with water from thewells) might cause non-cancerous health effects in adults, children, and the fetuses ofpregnant women, especially given the lead levels, the known health effects that mightresult from exposure to those levels, and the possibility for additional lead exposure thatmight occur from the workplace and the environment. According to the data given inTable 13, the numbers of people who use these wells are the following: 1 person (372A),72 people (540A), 16 people (550A), 5 people (551A), 5 people (578A), 1 person(602A), and 4 people (603A).
Based upon the provisions documented in the Offpost ROD, of those wells discussedhere, only well 550A may not qualify for connection to a municipal water supply systemor an alternative water source. Human consumption of water containing about 65.5 ppblead may be resumed if the use of this well is continued. Non-cancerous health effectsmay occur in adults, children, infants, and the fetuses of pregnant women who use thiswell as a drinking water supply (including infant formula made with water from the well)and/or for cooking, as described above.
Lead was detected at a concentration of 98.8 ppb in the water of the private wellnumbered 579A (see Table 13). Lead was detected at a concentration of 18.6 ppb in thewater of the private well numbered 931A (see Table 14). Bottled water was not providedto the residents using these wells at the time this assessment was compiled, so it ispresumed that these wells are used as a drinking water supply and for activities such asshowering, bathing, and cooking. Both of these wells qualify for connection to amunicipal or alternative water source and, thus, use of these wells for drinking anddomestic water supply is not expected to continue.
Before replacement, non-cancerous health effects are not expected from the use of thewell water from these wells for showering, bathing, mopping, or other such householduses. However, non-cancerous health effects may result in children, infants, and thefetuses of pregnant women who use these wells as a drinking water supply (includinginfant formula made with water from the wells) and/or for cooking, especially given thelead level, the known health effects that might result from exposure to those levels, andthe possibility for additional lead exposure that might occur from the environment. Non-cancerous health effects are not expected in adults who use the well numbered 931A;however, non-cancerous health effects may occur in adults who use water from the wellnumbered 579A as a drinking supply or for cooking. According to the data given inTable 13, three people use the well numbered 579A, and according to the data given inTable 14, three people use 931A.
- In samples collected in the 1991-1994 interval, nitrate was detected at a concentration of10,000 ppb to 24,000 ppb in the well water from the wells numbered 456A, 579A, 739A,973A, and 1276A (see Table 13). Bottled water was not provided to the residents usingthese wells at the time this assessment was compiled, so it is presumed that the wells areused for drinking water and for activities such as bathing, showering, and cooking. However, based upon the decision documented in the Offpost ROD, all these wellsqualify for connection to a municipal water supply or an alternative water source and,thus, the use of these wells for drinking and domestic water supply is not expected tocontinue.
Prior to replacement with an alternative water supply, the non-cancerous health effectsthat may result from using these wells for showering, bathing, mopping, or other suchhousehold uses are unknown, because very little information exists to assess dermalexposures; inhalation is expected to be negligible. Adults and children drinking waterfrom these wells and cooking with it are not expected to develop non-cancerous healtheffects. However, non-cancerous health effects may result in infants, the fetuses ofpregnant women, and pregnant women from using the water from these wells fordrinking (including infant formula made with this water) and/or for cooking. Nitrate isknown to be taken into vegetables (see the Toxicological Evaluation section andAppendix B for more information). According to the data given in Table 13, threepeople each use most of these wells. Two people use the well numbered 456A, and sixuse 1276A.
Nitrate was detected at a concentration of 11,000 ppb to 26,000 ppb in the well waterfrom the wells numbered 331A, 332B, 332D, 540A, 541A, 547A, 551A, 578A, 613A,616A, 969A, 981A, and 1305A (see Table 13). Bottled water is provided to the residentsusing the water from these wells, so it is presumed that water from the wells is usedmainly for activities such as bathing, showering, and cooking.
Of the wells listed in this category, only well 547A may not qualify for connection to amunicipal water system or an alternative water supply. However, the level of nitratecontamination is this well has declined from its high level of 12, 700 ppb and the Januaryand July, 1995 samples collected from this well found 7,300 ppb and 6,600 ppb nitrate;below the 10,000 ppb MCL level of health concern.
Prior to replacement with an alternative water supply, the non-cancerous health effectsthat may result from using these wells for showering, bathing, mopping, or other suchhousehold uses are unknown, because very little information exists to assess dermalexposures; inhalation is expected to be negligible. Non-cancerous health effects are notexpected to result in adults or children who drink water from the well or eat food cookedwith the water. Nitrate is known to be taken into vegetables (see the ToxicologicalEvaluation section and Appendix B for more information). However, non-canceroushealth effects may result in infants, the fetuses of pregnant women, and pregnant womenfrom using the water from these wells for drinking (including infant formula made withthis water) and/or for cooking. According to the data given in Table 13, the followingnumbers of people use each of these wells: 331A (3 people), 332B (2 people), 332D (2people), 540A (72 people), 541A (3 people), 547A (3 people), 551A (5 people), 578A (5people), 613A (2 people), 616A (6 people), 969A (3 people), 981A (4 people), and1305A (2 people).
It should be noted that wells contaminated with nitrate are also frequently affected byelevated levels of coliform bacteria. Water treatment technologies used to eliminate orsignificantly diminish nitrate levels, such as ion exchange resins and reverse osmosis, arenot adequate to remove coliform bacteria.
- Several chemicals were detected in groundwater, surface water, soil, and/or air for which regulatory or other appropriate comparison values and health guidelines do not exist or are rather limited in their focus. A list of these chemicals and information concerning the need for comparison values and health guidelines for use in evaluating potential public health issues was submitted to the ATSDR Division of Toxicology. Those chemicals are bicycloheptadiene, dicyclopentadiene, ethylbenzene, methylphosphonate, parathion, supona, vapona, isodrin, dimethyldisulfide, CPMS/CPMSO/CPMSO2, and DIMP.
- Dieldrin has been detected above the FDA Action Level of 0.3 ppm in waterfowl, pheasants, and mourning doves inhabiting RMA. The birds are a potential pathway of off-site human exposure. Pheasants are less of a concern, given their estimated home ranges and the low concentrations of dieldrin detected thus far in the livers of off-site birds. Biomonitoring conducted by the USFWS in 1994 found that edible-tissue body burdens of waterfowl and mourning doves was below FDA Action Levels for dieldrin and other contaminants. Those data suggest that no adverse health effects would result from human consumption of those species.
- For the purposes of this public health assessment, ATSDR reviewed the existing studiesof the toxicological effects of Diisopropyl methylphosphonate (DIMP) and hasconcluded that the EPA LTHA of 600 ppb and RfD of 0.08 mg/kg/day are protective ofpublic health. ATSDR is preparing a Toxicological Profile for DIMP that will furtherevaluate the issue of potential human health risks that may be associated with exposure toDIMP. A public comment draft of that report is scheduled for release in the late Summeror Fall of 1996.
- Because some drinking water well owners in the Commerce City (OU 2) area have refused connection to municipal water and monitoring of those wells may be difficult, periodic review of available data describing the water quality of the Alluvial Aquifer in the Commerce City (OU 2) Area should be conducted. As long as it can be reasonably inferred that contamination of those wells remains above health-based levels, the well owners should periodically be provided with information, similar to the notification they previously received, describing the risks associated with the continued use of that well water.
- Lead, a non-RMA contaminant, has been detected in the water from wells numbered372A, 540A, 550A, 551A, 578A, 602A, and 603A. Bottled water is supplied to the usersof these wells. It is recommended that, until these residences have been connected to amunicipal water supply system or an alternate source of water, the practice of notifyingthe users of these wells of the well testing results be continued and that the notificationencourage the users of these wells not to use the water from these wells for drinking,cooking, or the preparation of infant formula. Of the wells listed, apparently only well550A does not qualify for connection to a replacement water supply.
Lead has also been detected in the water from wells numbered 579A and 931A. Bottledwater was not provided to the users of these wells at the time the data was compiled forthis assessment. It is recommended wells 550A, 579A, and 931A be resampled todetermine the current level of lead contamination locally present in the aquifer. If thelead levels remain elevated in these wells, the residents should be encouraged to connectto a municipal water supply system or to develop an alternate source of water. Thepractice of notifying the users of these wells of the well testing results should becontinued and the notification should encourage that children, infants, and pregnantwomen not drink the water (including infant formula made with this water) or eat foodcooked with it. In addition to children and infants, all adults should be discouraged fromdrinking the well water or eating food cooked with water from well 579A.
Proper use of filters on taps served by the wells will also significantly diminish theexposure to lead. The Toxicological Evaluation section and Appendix B containsadditional information on reducing exposure to lead.
- Nitrate, a non-RMA contaminant, was detected, in the water of numerous wells listed inTables 13 and 14 of this assessment. Nitrate levels in those wells was above the MCL of10,000 ppb in April 1994, but since then nitrate levels in those wells has continued todecline and, as of August 1996, none of those wells contain nitrate levels greater than the10,000 MCL value for nitrate.
Because all of those wells, except well 547A, qualify for connection to a municipal watersupply system or an alternative water supply continued use of those wells for drinkingand domestic water supply is not expected to continue. The use of well 547A maycontinue, but, at present, the level of nitrate contamination is below the MCL and level ofhealth concern. It is recommended that periodic testing of the nitrate level in well 547Abe performed and that the practice of notifying the users of this well of the testing resultsbe continued. The well user should be encouraged to test their well for the presence ofcoliform bacteria.
- ATSDR's Division of Toxicology should consider developing media-specific comparison values, health guidelines, or substance-specific applied research for the chemicals identified in Conclusion 8.
- We recommend that current-access and allowable-use restrictions set forth in the RMA policy memorandum of July 17, 1991, be maintained until superseded by a comparable remediation-action-specific system of access and use restrictions imposed to ensure the safety and well being of RMA workers and visitors. We also recommend that guests at the RMA National Wildlife Area receive health education via videos, short discussions, updated health and safety fact sheets, and pamphlets before their visits. USFWS should retain the lead in enforcing compliance with safety guidelines and educating visitors on the dangers of wandering onto restricted areas. If, prior to completion of the final site cleanup, unsupervised public access is permitted in some areas, maps provided to visitors and signs or markers in the areas managed as a wildlife refuge should clearly delineate areas where access is prohibited. We further recommend periodic updates of the access restriction map. We recommend that those access restriction map updates be developed in anticipation of the potential effects of planned or ongoing site cleanup measures to further ensure that no unanticipated conflicts arise with RMA National Wildlife Area users.
- We recommend continued enforcement of statutory and institutional controls that prohibit taking and consuming biota at RMA, particularly the catch and release program aimed at preventing consumption of fish in RMA lakes and the prohibition of taking deer for consumption.
- ATSDR should review key elements of the design of final site cleanup measures, including provisions for environmental monitoring, to ensure that appropriate steps have been taken to protect public health during the final remendiation process.
- ATSDR should review and coordinate with all members of the RMA Federal Facility Agreement any changes to the health and safety plan that has been established to ensure that the various agencies involved in remediation at RMA adhere to current industrial hygiene standards to prevent harm to remedial and maintenance workers.
- The Comprehensive Environmental Response Compensation, and Liability Act(CERCLA; also known as Superfund) as amended, requires ATSDR to conduct neededfollow-up health actions in communities living near hazardous waste sites. To identifyappropriate actions, ATSDR created the Health Activities Recommendation Panel(HARP). HARP has evaluated the data and information contained in the RockyMountain Arsenal Public Health Assessment for appropriate public health actions. HARP determined that both Community Health Education and Health ProfessionsEducation are warranted because, as discussed above, exposure is now occurring toseveral chemicals in specific drinking water wells above health-based guidelines. Inaddition, health studies are underway. When those studies are completed, ATSDR willevaluate them for the need for further follow-up public health actions. Media-specifichealth guidelines are not available for some of the substances detected. Those substanceswill be referred to ATSDR's Division of Toxicology for consideration of comparisonvalues, health-based guidelines, or substance-specific applied research.
The public health action plan (PHAP) for the Rocky Mountain Arsenal (RMA) contains adescription of actions to be taken by ATSDR and/or other governmental agencies at and in thevicinity of the sites subsequent to the completion of this public health Assessment. The purposeof the PHAP is to ensure that this Assessment not only identifies public health hazards but alsoprovides a plan of action designed to mitigate and prevent adverse human health effects resultingfrom exposure to hazardous substances in the environment. The PHAP includes a commitmenton the part of ATSDR to follow up on this plan to ensure that it is implemented. The followingpublic health actions have been undertaken or are planned:
A. Actions Undertaken
Before the beginning of this Assessment, RMA, USFWS, EPA, TCHD, and CDPHE tooknumerous actions that contribute to or are protective of public health. The text of thisAssessment summarizes most of those actions. The Agreement for a Conceptual Remedy for theCleanup of the Rocky Mountain Arsenal (Colorado, 1995) and the subsequent finalization ofboth the Offpost ROD (HLA, 1995 and the Onpost ROD (Foster Wheeler, 1996) have specifiedthe scope and nature of the final cleanup of RMA and numerous actions designed to beprotective of the public health during and after the cleanup. All parties to the ConceptualAgreement have actively participated in the furthering of the goals of Component 18 (MedicalMonitoring) of that agreement. Specific mention is not made below of all such Component 18actions taken by all parties, but the cooperation of all parties is recognized and appreciated. Many of those actions have already been initiate and will be noted in this section, along withother actions taken since the preparation of this Assessment began in January 1993.
- Reviewed the USFWS Addendum to Amendment 5 of the 1994 Fish and Wildlife Management Plan - Biomonitoring Program. One of the main objectives of the plan is to characterize the potential for contaminant uptake into the fish and wildlife of RMA.
- Reviewed the USFWS Health and Safety Plan, which is the basis for the plan of action for USFWS volunteers, employees, and public use of the National Wildlife Area. The objective of the Health and Safety Plan is to prevent or minimize exposure of workers and the public to hazardous chemicals remaining onsite.
- Assisted the USFWS in the development of a fact sheet on public health considerations relating to public use of the refuge. The fact sheet presents information that can be used to prevent or minimize public exposure to hazardous chemicals present onsite.
- Assisted and will continue to assist CDPHE and CSU in completing health studies relating to possible past exposures of people to RMA contaminants.
- Compiled a Toxicological Profile on DIMP that is scheduled for release as a public comment draft in late Summer or Fall of 1996 by ATSDR's Division of Toxicology.
- Participated in the establishment and monthly meetings of the Medical MonitoringAdvisory Group (MMAG, see CDPHE entry below) and actively worked to develop atechnical framework for and an increased level of community information andinvolvement in the development of the followup public health actions that may beappropriate during the final cleanup of the Arsenal.
The CDPHE has:
- Consistent with the provisions of the Conceptual Agreement (Colorado, 1995) and bothRODs (HLA, 1995; Foster Wheeler, 1996) organized the Medical Monitoring AdvisoryGroup (MMAG) to assist CDPHE ad ATSDR in the design of a medical monitoringprogram: a public health action plan to help ensure the protection of individual andcommunity health during the final cleanup of RMA. The first MMAG meeting was heldin December 1996 and the monthly meeting will occur until the group's objectives areachieved. In addition to the CDPHE and ATSDR representatives, the MMAG iscomprised of representatives of the neighborhoods near RMA, the Army, Shell OilCompany, EPA, TCHD, and area health care providers.
The USFWS has:
- Implemented, managed, and updated, in conjunction with the Army, the Activities Coordination program that coordinates all remediation, scientific research, and public use activities on RMA. This on-going program includes production of a weekly map and a schedule that designates locations of all activities, with a special designation for tasks that represent a significant hazard to other field activities. The schedules include type, location, duration of activity, level of Personal Protective Equipment required, and a specified point of contact. To prepare for weekly meetings, the USFWS collects the information one week in advance for consolidation and dissemination by facsimile transmission. All revisions are kept at the Activities Coordination Office of the USFWS (USFWS, 1993b).
- Created and maintained a health and safety plan to ensure a safe working environment for arsenal employees, contractors, research assistants, and volunteers conducting a wide variety of scientific and public use tasks. Health and safety training covers all USFWS employees on all- terrain vehicle use, aircraft safety, equipment operation, OSHA hazardous waste protection procedures, cardiopulmonary resuscitation (CPR), and first aid. USFWS has also established monthly health and safety orientations, and the agency maintains a two-way radio communication system for reporting emergency situations (USFWS, 1993b).
- Ensured that agency employees receive physical examinations and medical monitoring as prescribed in the Medical Monitoring Policy outlined in the USFWS memo dated February 23, 1993. The results of those examinations are used to assess and monitor the health of their employees (USFWS, 1993b).
- Provided an ongoing National Wildlife Area visitor safety program. The program includes daily reviews of bus tour routes basis to ensure the routes' compatibility with other arsenal field activities. It also addresses health and safety concerns regarding anglers and fishing programs for children and the handicapped. (USFWS, 1993b).
- Designed a wildlife study and sampling plans that resulted in thorough evaluations of contaminant levels in the fish and wildlife species that inhabit or frequent RMA. In addition to monitoring the relative health of those fish and wildlife populations, the data derived permitted further evaluation of a potential foodchain pathway.
- Participated actively in the meetings and work of the MMAG
The U. S. Army has:
- Completed, under the direction of the U. S. Army Environmental Hygiene Agency, the development of a methodology for the analysis of DIMP in produce. The Arsenal, with the assistance of TCHD, collected and analyzed vegetable produce collected in the Offpost Study Area to permit a more thorough evaluation of a potential foodchain pathway.
- Participated actively in the meetings and work of the MMAG. Along with personnel ofShell Oil Company, RMA has worked actively to assure that adequate funding isavailable to enable the work of the MMAG.
B. Actions Planned
- Actively cooperate and assist, as necessary, the CDPHE in the planning and implementation of an integrated mosaic of public health actions responsive to the goals of Component 18 of the Conceptual Agreement and the requirements of the Offpost and Onpost RODs.
- As needed, plan and produce community involvement and information activities including informational meetings, handouts, and press releases, consistent with the PHA process, after the release of this public health assessment.
- Consider development of media-specific comparison values, health guidelines, or substance-specific applied research for the following compounds: bicycloheptadiene, dicyclopentadiene, ethylbenzene, methylphosphonate, parathion, supona, vapona, isodrin, dimethyldisulfide, and CPMS/CPMSO/CPMSO2.
- As needed, assist the CDPHE and the USFWS in the development of public health education materials for distribution to residents of nearby neighborhoods and to visitors to the RMA National Wildlife Area.
- As needed, provide or assist in securing health professionals education to ensure proper recognition and treatment of the possible health effects of environmental exposure to contaminants detected in water from Offpost Study Area private wells or to contaminants that might be accidentally released during finally site cleanup.
- As needed, assist CDPHE or others to provide community health education activities toprovide area residents with information about the levels at which health effects arepossible from exposure to lead and nitrate detected in well water from Offpost StudyArea private wells (see Tables 13 and 14) and how to reduce or stop their exposure tolead and nitrate.
- Review the findings of future RMA-focused health studies for public health significanceand future follow-up public health actions when the studies are completed. ATSDR will,as appropriate, submit the findings of these studies to other members of the FederalFacility Agreement (FFA) and the public for review and comment.
- Develop an integrated and comprehensive public health action plan (Component 18 Medical Monitoring Plan) to ensure protection of the public health of the nearby neighborhoods during the extended final cleanup of the Rocky Mountain Arsenal.
- Inform and involve the communities near RMA, the members of the MMAG, the Parties,health care professionals, and other interested parties during the development of theMedical Monitoring Plan.
Tri-County Health Department will:
- As appropriate, continue to monitor the quality of drinking water wells that remain in use in use in the Offpost Study Area and to send written notification to owners and users of contaminated drinking water wells, or to the owners/users of drinking water wells that may be contaminated in the future, of the health threat(s) that may be associated with the use of their well water.
- Ensure that drinking water wells identified in this assessment that do not qualify for areplacement water source and that may represent a potential health threat from human exposure to elevated levels of lead or other contaminants are retested periodically andtheir owners sent written notification of the health threat(s) that may be associated withthe use of their well water.
- To the extent there is data or a reasonable basis to infer the continued contamination of the Alluvial Aquifer in the vicinity of those private drinking water wells in the OU 2 areaof Commerce City that remain in use, in cooperation with local heath officials, providenotification to the well owners of the health risks that may be associated with thecontinued use of those wells.
The U. S. Army will:
- Coordinate with USFWS representatives throughout the final remediation process toreview data relevant to contamination sources and remediation activities and, asnecessary, to update or revise the RMA access map and/or activity and wildlife refugeuse coordination requirements.
W. Mark Weber, Ph.D.
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Linda K. West, M.S.P.H.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Gary H. Campbell, Ph.D.
Chief, Section B
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Glenn Tucker, Ph.D.
Sr. Regional Representative
ATSDR Region VIII
Susan L. Muza, M.P.H.
ATSDR Region VIII
Figure 1 - Location of Rocky Mountain Arsenal