Application of AERMOD to Native American Human Health Risks from Chemical Weapons Incineration at the Umatilla Chemical Depot Rodney Skeen May 2013

Presentation Overview Background on CTUIR and UMCD Human health risk assessment basics Site specific data Human health risk results Process modification to reduce risk AERMOD and Transportation Risk Summary

Historical Territory of the CTUIR UMCDF Reservation

Umatilla Depot (UMCD) Army granted 14,000 acres in 1941 for munitions depot (expanded to over 19,000) Chemical munitions have been stored since 1962 Site stored 12% of the original U.S. stockpile of chemical agents Nerve agents GB (sarin) and VX Blister agent HD On-site incinerator destroying munitions Incinerator started in 2004, operated until 2012, full closure complete in 2014.

Simple Question to Answer What operating conditions for the UMCDF ensure that emissions do not create unacceptable risks to surrounding populations?

Acceptable Limits 2004 HHRA Work Plan established the following limits: No individual Cancer Risks above 1E-6 Total Cancer Risk below 1E-5 Individual Hazard Quotient below 0.25 Total HI for specific effect and organ below 0.25 Acute Inhalation HQ for individual compounds below 1.0 Ecological Screening Quotients below 1.0

Example Conceptual Model

Steps to Risk Assessment Identify emissions characteristics (flow rate, particulates, composition, temperature, etc) Model contaminant transport and deposition through the air Estimate exposure mechanisms Exposure routs (inhalation, dermal contact, ingestion) Lifestyle Estimate toxicity of each compound Compute dose and risk

Modeling Transport and Deposition – Data Requirements } Air Modeling Meteorological data Topography data Land use Building geometric data Source geometry data Source emission data Risk data

Tools in Risk Assessment Air transport and deposition modeled using Lakes Environmental implementation of AERMOD Risk and ecological risks modeled using modified versions of Lakes Environmental IRAP-h and EcoRisk

Emissions Characteristics (1) – Four Point Sources LABSTK MDBSTK BRASTK COMSTK N Laboratory Brine Reduction Area Munitions Demilitarization Building Pollution Abatement System Personnel and Maintenance

Emission Characteristics (2) – Common Stack Common stack receives emissions from four very different furnaces (Liquid incinerators 1&2, Deactivation Furnace, Metal Parts Furnace) Use of each furnace varies by type of munitions begin processed Time weighted scaling methodology was developed to estimate a single emissions rate for evaluating chronic risks Upset for each furnace evaluated separately for estimating acute risks

Emission Characteristics (2) – Common Stack Furnaces DFS LIC MPF All furnaces have afterburners, wet pollution abatement, and carbon filters

Source Emission Data Parameter Common Stack BRA Stack MDB Stack LAB Stack Base Elevation (m) 183 182 Stack Height (m) 30.5 19.8 36.6 12.2 Gas Temperature (K) 340.1 449.8 294.3 298.7 Exit velocity (m/s) 1.75 13.01 12.73 18.3 Diameter (m) 1.52 1.37 2.19 0.64 Time of Operation (yr) 10 Emissions data collected from trial burns at UMCDF and other demilitarization sites Particle size distribution data also collected

Emissions Distribution for Common Stack Common Stack Emission Distribution – What you don’t know may kill you.... Emissions Distribution for Common Stack (Based on HHRA Values) Less than 2% of emitted organics were identifiable

Meteorological Data (1) Six years of on-site surface data 2 meter temperature 10 meter speed, direction, STDEV, temperature 30 meter speed, direction, STDEV, temperature Solar insulation, precipitation, pressure Upper air data from Spokane Washington Merged using AERMET View

Topography Data Topography data taken from USGS DEM maps downloaded from Lakes Environmental (www.webgis.com) Data imported using ISC-AERMOD View Map tool Columbia River Umatilla

Land Use Water Body Range Land Agricultural Land

Example Deposition Map – Unitized Vapor Phase Air Concentration (ug/m3 per g/s)

Deposition Grid and Evaluation Points Receptor Locations 50 km

How toxic is each chemical Estimating Exposure (Dose) Scenario Exposure Where you go × = DOSE RISK What you do What contaminants are in each medium – air, water, soil, food… How toxic is each chemical What you eat

Accounting for Cultural Contact Harvesting Drying Cooking

Cultural Contact Through Sweat Lodge Activity Characteristics 100% humidity 150 F Active behavior Water Rocks

Native American Subsistence Scenario (NASS) Live 70 years in one location (whole life) Active lifestyle No vacation 100% of produce grown locally 100% Meat/Fish from impacted area Different dietary pattern Higher caloric intake (2500 kcal/day). High fish intake Consumption of whole animal Unique exposure pathways Sweat lodge Native medicines Cultural practices (hunting, fishing, gathering, weaving, tanning)

Base Model Results Some areas of concern, lets look at details …. Location Scenario Cancer Risk Hazard Index Off Site Farmer Adult 2.6E-04 0.33 Farmer Child 3.0E-05 0.41 Fisher Adult 2.1E-06 0.11 Fisher Child 1.4E-06 0.28 Native Adult 3.0E-04 Native Child 2.3E-05 0.42 Resident Adult 2.0E-06 Resident Child On Site 1.5E-02 7.80 1.6E-03 9.84 1.2E-04 2.73 8.0E-05 6.65 1.6E-02 9.83 1.3E-03 10.00 On Site /Off Site Worker Adult 5.2E-06 0.15 Admin Area/Off Site Military Adult Some areas of concern, lets look at details ….

Hazard Index (% of Total) Base Model Results- Point Source Contribution to Non-Cancer Chronic Risk Stack Hazard Index (% of Total) Native Adult Child Fisher Farmer Resident BRASTK 59.4% 59.6% 59.7% 59.5% COMSTK 1.8% LABSTK 5.9% MDBSTK 32.9% 32.7% 32.6% Total HI 0.41 0.42 0.28 0.33 BRA stack was the largest point source contributor. GB, VX, and HD created more than 99% of the non-cancer risk, but are undetected compounds assumed present at just below the detection limit for the continuous monitoring units.

Rethinking Assumptions (1) Reviewed process data and realized that the confirmatory agent monitoring system has lower detection limit. These units rely on a collection tube and are periodically sampled. Off-site shipment of brine for treatment is viable alternative to operation of Brine Reduction Area (BRA) Re-analyzed risk at lower HD/GB/VX emission levels and no BRA operation during HD campaign

Rethinking Assumptions (2) Location Scenario Cancer Risk Hazard Index Off Site Farmer Adult 1.5E-04 0.0038 Farmer Child 1.7E-05 0.0051 Fisher Adult 1.2E-06 0.0016 Fisher Child 7.7E-07 0.0035 Native Adult 1.6E-04 0.0050 Native Child 1.3E-05 0.0055 Resident Adult 1.1E-06 0.0013 Resident Child On Site 8.1E-03 0.0988 8.9E-04 0.1284 6.6E-05 0.0323 4.5E-05 0.0816 9.0E-03 0.1088 6.9E-04 0.1270 On Site /Off Site Worker Adult 4.0E-06 0.0031 Admin Area/Off Site Military Adult Non-cancer risks Are all below action levels These operational changes were made

Base Model Results- Point Source Contribution to Cancer Chronic Risk Stack Cancer Risk (% of Total) Native Adult Native Child Farmer Adult Child BRASTK 0.0% COMSTK 100.0% LABSTK MDBSTK Total CR 3.0E-04 2.3E-05 2.6E-04 3.0E-05 Over 99% of the cancer risk from COMSTK is a result of the unidentified non-volatile TOE fraction which was assigned a surrogate toxicity based on geometric mean of the compounds in the corresponding boiling point group EPA Guidance does not require quantitative evaluation of this fraction because of its uncertainty. Was evaluated by Army because of CTUIR concerns

Rethinking Assumptions (3) – CSF of Unidentified Non-Volatile Organic Dioxins/Furans 7,12-Dimethylbenz(a)anthracene Benzidine Mean if D/F are set at detection levels Eleven D/F and one PCB cause large increase in CSF geometric mean

Rethinking Assumptions (4)- Including D/F at detection limits Unspeciated Computed from total mass measurement Rethinking Assumptions (4)- Including D/F at detection limits ACTION: Modified sampling and analysis methods to identify more of the organic fraction and to lower detection limits. GravFrac=Polystyrene? (FTIR) Included D/F and other PAH compounds at their Detection Limit Two on-site scenarios still predicted to be above action levels 99% of predicted risk still driven by unidentified non-volatile organic Unidentified means the real risk is uncertain FTIR suggests unspeciated is polystyrene Location Scenario Cancer Risk (if PAH at DL) Cancer Risk (if Not PAH) On Site Farmer Adult 1.8E-04 1.6E-05 Farmer Child 2.5E-05 3.1E-06 Fisher Adult 1.4E-06 1.1E-06 Fisher Child 9.7E-07 8.5E-07 Native Adult 2.0E-04 1.9E-05 Native Child 2.0E-05 2.9E-06 Combined Worker Adult 2.7E-08 2.3E-08 Military Adult 9.7E-08 8.3E-08

Closure Sampling Area Remaining Compounds of concern have resulted in implementing a closure sampling strategy in the zone of potential plume deposition Soil Sampling Results will be used for risk based closure.

Modeling Truck Accident and Chemical Agent Spill with AERMOD Vapor Concentration Exposure Point Emission Rate (g/s) Point or Area Source Exposure Time

Based On Placard Only (m) Agent Based On Placard Only (m) Small Spill Large Spill Primary Isolation Zone (m) Secondary Isolation Zone (m) GB 25 60 400 800 2300 VX 30 100 HD 500 USDOT Emergency Response Guidebook Exposure Scenarios Concerned Motorist - 10 minutes of exposure in spill area First Responder – 1 hour at 25 meters General Public – 2 hours at maximum concentration within 50 m and Secondary Isolation Boundary. First Responder Scenario evaluated at 25 m Primary Isolation Zone Boundary. 50 m Boundary Spill Area Concerned Motorist Scenario Evaluated Within Spill Area. Evaluation Compared dose with Acute Exposure Guideline Levels General Public Scenario Evaluated Within the Area Between 50 m and the Secondary Isolation Zone. DOT Secondary Isolation Zone (Set by First Responders)

Conclusions AERMOD used to model emission from a chemical munitions incinerator at Umatilla, Oregon Emissions use to evaluate future health risks to Native Americans using the impacted lands. Risk results led to operation changes and modified closure strategy. AERMOD also applied modeling plume development

Contact Information Rod Skeen, Ph.D., P.E. Division Leader (541) 429-7420 rodskeen@ctuir.org Barbara Harper, Ph.D. (541) 429-7950 Barbaraharper@ctuir.org