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HomeMy WebLinkAboutDSHW-2010-052647 - 0901a068801e2e1a (5) July 8, 2010 David P. Gosen, P.E. Director, Environmental Services ATK Launch Systems – Promontory P.O. Box 707 Brigham City, UT 84302-0707 RE: Human Health Risk Assessment Protocol for OB/OD Operations ATK Launch Systems - Promontory Facility UTD009081357 Dear Mr. Gosen: The Division of Solid and Hazardous Waste has completed its review of ATK’s Human Health Risk Assessment Protocol for OB/OD operations. The risk assessment will be used when preparing conditions for ATK’s Subpart X Permit. Our comments and questions on the documents are enclosed with this letter. In regard to the list of compounds that ATK proposed to drop from further consideration in the risk assessment (correspondence dated November 5, 2009), the Division agrees that all of the compounds may be dropped except for 1,2-dibromoethane. This compound’s primary uses, as a leaded gasoline additive and fumigant, aren’t a concern at ATK. However, this compound may be used, to a lesser extent, in the manufacturing of polymers and resins. Please provide additional information to demonstrate that 1,2-dibromoethane is not a component of any of the polymers or resins that are used in the various ATK propellant formulations. As you are aware, the Division is committed to completing permitting work for the Subpart X units by the end of September 2010. Due to the short amount of time left to accomplish this, we request that ATK submit its responses to the attached comments by August 1, 2010. July 8, 2010 Page 2 TN201000540 If you have any questions, please contact Jeff Vandel at (801) 536-0257. Sincerely, ORIGINAL DOCUMENT SIGNED BY SCOTT T. ANDERSON 7/8/2010 Scott T. Anderson, Director STA\JV\tjm Enclosure c: Nancy Morlock, Region 8 EPA George Gooch, ATK Launch Systems Blair Palmer, ATK Launch Systems Lloyd Berentzen, Deputy Director, Bear River Health Department TECHNICAL REVIEW OF THE HUMAN HEALTH RISK ASSESSMENT PROTOCOL FOR USE IN THE SUBPART X PERMITTING OF THE OPEN BURNING AND OPEN DETONATION OPERATIONS DATED FEBRUARY 10, 2010 GENERAL COMMENTS: Given that there are special considerations in the evaluation of mercury exposures, please revise the open burning (OB)/open detonation (OD) HHRA Protocol to clarify how mercury will be evaluated. Specifically, please clarify that the risk assessment will evaluate exposure to three mercury species via varied pathways (pg. 2-46 and 2-47 of EPA’s Human Health Risk Assessment Protocol (HHRAP) for Hazardous Waste Combustion Facilities dated September 2005): Assess elemental mercury only through direct inhalation of the vapor phase; Assess divalent mercury through both direct inhalation and indirect exposure to vapor and particle-bound mercuric chloride; and Assess methyl mercury only through indirect exposure. If mercury speciation will not be evaluated as described above, or if particular exposure pathways are excluded, please provide sufficient justification for the proposed approach. The OB/OD HHRA Protocol does not clarify which compounds, if any, will be evaluated qualitatively in the HHRA. Please revise the OB/OD HHRA Protocol to provide a discussion of the methodologies to be employed in qualitative assessment of chemicals of potential concern (COPCs) that are not otherwise sufficiently evaluated on a quantitative basis. While the OB/OD HHRA Protocol indicates that the exposure factors will be those published in EPA’s 2005 HHRAP, it is recommended that a table be included that provides the exposure factors to be used for each relevant pathway based on exposed/potentially exposure receptor populations (i.e., for each scenario evaluated in the OB/OD HHRA Protocol, including the current/future industrial worker scenario) as well as the associated fate and transport parameters. At a minimum, these will need to be provided in the subsequent HHRA so that they may be verified. Section 5.0, Uncertainty, of the OB/OD HHRA Protocol states the Open Burn Open Detonation Model (OBODM) does not provide output for particle-bound phase constituents. The text continues that omission of gravitational deposition results from the OB/OD risk assessment will be addressed as a source of uncertainty. As discussed in Section 3 of EPA’s 2005 HHRAP, particle deposition is addressed in two phases, the particle phase and the particle-bound phase. Constituents present in the particle phase are modeled using a mass weighting of the assumed particle size distribution while particle bound phase constituents are modeled using a surface area weighting of the assumed distribution. Section 3.2.3 of the HHRAP outlines a technique for calculating the surface area weighting factors from the mass fractions for each particle size category. Further, Section 3.2.3 indicates a separate particle-bound phase run is necessary using the surface area weighting scheme when modeling with ISCST3. The same is true for OBODM. The user must provide the surface area weighting factors for the assumed particle size distribution in a separate model run to produce estimates of gravitation deposition for particle-bound constituents. Please revise Section 5.0 to eliminate the omission of particle-bound phase gravitational deposition results as a source of uncertainty in the OB/OD risk assessment. Please also revise other sections of the OB/OD HHRA Protocol (e.g., Sections 3.3.1, 3.3.2, and 3.3.4) to include particle-bound phase concentrations and deposition. SPECIFIC COMMENTS: Section 2.0, Identification of Constituents of Potential Concern, Page 2: Section 2.0 indicates that criteria pollutants will be excluded from the HHRA. Please clarify in this section that the criteria pollutants will be evaluated by comparing the modeled concentrations to the National Ambient Air Quality Standards (NAAQS) and clarify if background air quality data will be used in the evaluation. In addition, from a review of the COPC list, lead (a criteria pollutant) will be evaluated quantitatively. For clarification, please indicate in Section 2.0 that lead will be the only criteria pollutant evaluated in the OB/OD HHRA. Section 2.0, Identification of Constituents of Potential Concern, Page 2: Section 2.0 also states that “low molecular-weight volatiles (ethane, ethylene, and methane) that have very low human toxicity and do not bioaccumulate up the food chains will not be evaluated in the HHRA.” However, Table 1, Chemicals of Potential Concern Evaluated in the Human Health Risk Assessment, indicates that ethylene will be evaluated quantitatively. Please resolve this discrepancy. Ethylene should be retained as a quantitative COPC. Also, if any subject VOCs are being eliminated as a COPC, please list them. 3. Section 3.1, Exposure Setting Characterization, Page 3: In a review of Section 3.1, the predominant wind direction is not clearly presented. Please revise Section 3.1 to include this information. Additionally, it is unclear whether there is a county zoning map available for review. If such a map is available, it should be referenced and discussed within the context of surrounding land use and associated receptor populations in the OB/OD HHRA. 4. Section 3.1, Exposure Setting Characterization, Page 3: It is stated in this section that “the general receptor grid will be used to determine the maximum one-hour and annual vapor and deposition concentration location(s) beyond the ATK facility boundary.” Based on the 2005 HHRAP guidance regarding potential future land uses, and the study area conditions, the general receptor grid should also be used to determine at least the maximum annual deposition concentration location within the10 km grid, regardless of the facility boundary, for evaluating potential future exposure pathways. This issue is discussed in more detail in comment number six below. 5. Section 3.1, Exposure Setting Characterization, Page 3: One of the discrete receptors listed in this section is the “Holmgren Ranch Pond.” As stated in Section 3.2, ingestion of fish and surface water will not be evaluated due to site conditions. Is ingestion of fish a potential exposure pathway at the Holmgren Ranch? If not, please remove “pond” from this receptor and evaluate exposure pathways as applicable to the Holmgren Ranch. As indicated in this section, discrete receptors were discussed during a meeting held in 2002. ATK has added several important discrete receptors to the list for evaluation. It is felt that the Thiokol Ranch could be dropped from the list since ranches located much closer to the burn grounds will be evaluated. However, two discrete receptors which were discussed previously were left off the list. Bird hunting is conducted at the Salt Creek Waterfowl Management Area and Bear River Migratory Bird Refuge (both located within 10 km of the M-225 Burn Grounds) so ingestion of potentially contaminated birds appears to be an exposure pathway. Please include these areas as discrete receptors to be evaluated in the HHRA. 6. Section 3.1, Exposure Setting Characterization, Page 4: While Figure 1 depicts the discrete receptors, it would be helpful if Figure 1 was revised to depict a 10 kilometer (km) radius surrounding the OB/OD units (i.e., M-136 and M-225). Also, a land use/land cover (LULC) map and an aerial photograph have not been provided. Please include a LULC map and an aerial photograph to assist in the understanding of the exposure setting. 7. Section 3.1, Exposure Setting Characterization, Page 4: It does not appear that any sensitive subpopulations (e.g., schools, retirement communities, civic centers, etc.) are located within the 10 km assessment area or beyond. However, please clarify whether sensitive subpopulations occur anywhere near the facility. Section 3.2, Exposure Scenarios, Page 4: Section 3.1 provides a list of discrete receptor locations to be evaluated in the OB/OD HHRA. However, Section 3.2 does not clarify the exposure pathways evaluated at these locations. Many discrete locations appear to relate to adult and child residents, but it is unclear whether an adult and child farmer/rancher may be evaluated at any of these locations. Please revise the OB/OD HHRA Protocol to include a table which provides the discrete exposure receptor location and the exposure scenarios evaluated at those locations. Also, please propose a location where a future hypothetical adult/child resident will be evaluated [preferably a location representative of the maximally exposed individual (MEI)]. 9. Section 3.2, Exposure Scenarios, Page 4: The 2005 HHRAP indicates that reasonable potential future land uses should be included when identifying exposure scenarios to evaluate in the HHRA. Furthermore, the guidance document states that undeveloped rural areas could reasonably be expected to become farmland if it is able to support agricultural activities. Due to the fact that the area around the facility does support agricultural activities (primarily ranching) and that grazing has occurred within the facility boundaries in the past, please evaluate potential future exposure pathways that may exist inside the facility boundaries. In addition, the statement “if the site were developed for agricultural or residential purposes in the future then most likely the source areas would be removed” should be revised. It is unlikely that contaminants that may get widely deposited on potential range land would be removed, as demonstrated by the molybdenum contamination that was deposited on lands adjacent to the M-225 Burn Grounds. Please revise the HHRA Protocol to include an evaluation of the farmer/farmer child exposure scenario (sans direct inhalation of vapors and particles) for this potential future land use at the location of the maximum on-site impact. Section 3.2.1, Farmer and Farmer Child, and Section 3.2.2, Adult and Child Resident, Page 6: These sections indicate that these exposure scenarios include the evaluation of ingestion of breast milk from “only dioxins/furans.” Please note that the 2005 HHRAP also indicates that dioxin-like polychlorinated biphenyls (PCBs) should also be evaluated for this pathway. Please revise the OB/OD HHRA Protocol to indicate that dioxin-like PCBs will also be evaluated for this pathway, or provide adequate justification for not doing so. Please ensure that OB/OD HHRA Protocol tables are updated accordingly. 11. Section 3.2.4, Industrial Worker (AutoLiv) and Future Worker, Page 7: The ATK facility covers a large area and employs many people that are unassociated with the operations at the burn grounds. Please provide an explanation for why it is planned to limit the industrial worker scenario evaluation to AutoLiv workers. 12. Section 4.3, Risks for Nursing Infants, Page 14: Please list the compounds included in the evaluation of the breast milk pathway. Also, please note that the 2005 HHRAP contains outdated World Health Organization (WHO) toxicity equivalency factors (TEFs) for dioxins and dioxin-like compounds. The most recent WHO TEFs may be accessed at: http://www.who.int/ipcs/assessment/tef_update/en/ Please ensure that nursing infants are evaluated based on the utilization of current TEFs. 13. Section 4.6, Comparison of Modeled Air Concentrations to Utah Toxic Screening Levels (TSLs), Page 16: While a comparison of modeled air concentrations to TSLs is one line of evidence, it should not preclude quantitatively evaluating exposures, i.e., this comparison to TSLs should not serve as a rationale for not assessing a particular exposure. The risk assessment must provide for an understanding of baseline risk/hazard, inclusive of all relevant pathways. Please ensure that the OB/OD HHRA quantifies all relevant exposures. Provided that the OB/OD HHRA quantifies all relevant exposures, ATK may compare and contrast projected concentrations to the TSLs within the context of the uncertainty analysis for the purposes of risk or site-management decisions. 14. Table 1, Chemicals of Potential Concern Evaluated in the Human Health Risk Assessment: There are several compounds listed that are not being evaluated quantitatively. Please clarify in the Table 1 footnotes why these compounds are not being evaluated quantitatively in the OB/OD HHRA, and indicate whether they are being evaluated qualitatively. If these compounds are not being evaluated qualitatively (i.e., eliminated from the risk assessment), please provide the associated rationale. 15. Table 3, Site-Specific Input Values: It is unclear why 30.54 cm/yr was selected as the average annual irrigation when, according to Baes et al. (1984), the facility is located in an area that has an average annual irrigation range of 55 to 70 cm/yr. Please justify the use of the selected value. It appears that the runoff value of 2.54 cm/yr may be incorrectly cited as this information could not be found in the cited reference document. Please double-check the site-specific values and ensure that they are properly referenced. If any assumptions were made, please ensure that they are noted and adequately supported in the footnotes. 16. Table 4, Chemical Specific Input Parameters Not in HHRAP Database, Table 5, Biotransfer Factors for Chemicals Not in HHRAP Database: Table 1 lists 103 quantitative COPCs that are not listed in the HHRAP Companion Database. However, Tables 4 and 5 list 77 compounds. Please address this discrepancy. Additionally, please reference the various databases used to obtain chemical properties (e.g., Chemfate? Etc.?) and the specific equations in HHRAP used to calculate biotransfer factors. 17. Table 5, Biotransfer Factors for Chemicals Not in HHRAP Database: Table 5 lists numerous compounds for which biotransfer factors were calculated. Please provide the calculations for all biotransfer factors for at least one compound so the equations/approach may be appropriately verified against the HHRAP. 18. Table 6, Changes in Human Health Toxicity Data: Please ensure that Table 6 is updated appropriately to reflect any changes in toxicity data for additional COPCs selected as a result of addressing Utah DSHW comments. 19. Table 7, Human Health Toxicity Data for Chemicals Not in HHRAP Database: Seventy-seven compounds are listed, not 103. Please resolve this discrepancy. Also, additional concerns were identified for Table 7. First, it appears that a number of compounds are listed twice (e.g., propylene, ethylene, etc.). Also, the toxicity criteria of various compounds appear incorrect. For example, Table 7 indicates that propylene (entered twice in Table 7) has an oral reference dose of 3 mg/kg/day and an inhalation reference concentration of 3 mg/m3. However, propylene does not have a federally-promulgated reference dose. Additionally, it appears that Freon 113 should have been selected as a surrogate for Freon 114 (rather than dichlorodifluoromethane) and that acrolein should have been selected as a surrogate for methacrolein (rather than acetaldehyde). Please review Table 7 closely and correct the toxicity criteria where applicable and remove duplicate entries. Additionally, please revise the OB/OD HHRA Protocol to provide adequate justification for the selected surrogates and update the selected surrogates for Freon 114 and methacrolein, or alternatively, provide adequate justification for not doing so. 20. Table 8, Acute Inhalation Exposure Criteria for Chemicals Not in HHRAP Database: Table 8 indicates that all acute inhalation exposure criteria (AIEC) were obtained from the U.S. Department of Energy Protective Action Criteria (PAC), which includes acute inhalation exposure guidelines (AEGLs), Level 1 emergency planning guidelines (ERPGs) and temporary emergency exposure limits (TEELs). However, according to the HHRAP and Section 4.4 of the OB/OD HHRA Protocol, Cal/EPA Acute Reference Exposure Levels (RELs) are the preferred AIEC, and from a cursory review of Table 8, it appears that RELs are available for some compounds. For example, the Cal/EPA REL for copper is 0.1 mg/m3, which is less than the PAC guideline of 3 mg/m3. Please review Table 8 and update the AIEC values where applicable (e.g., copper). 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880 Telephone (801) 536-0200 • F ax (801) 536-0222 • T.D.D. (801) 536-4414 www.deq.utah.gov TN201000540 Printed on 100% recycled paper State of Utah GARY HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Smith Executive Director DIVISION OF SOLID AND HAZARDOUS WASTE Scott T. Anderson Director