### Dispersion Modeling of Incinerator Stack Emissions at Ony x Environmental Services, Inc. (formerl y Trade Waste Incineration)

Sauget, Illinois

Prepared By : Todd D. Ramaly

_________________________________________ U.S. Environmental Prote ction Agency RCRA Programs Section June 15, 2006

### I - 1

**I. Executive Summary**  In November 2000, the United States Environmental Protection Agency (U.S. EPA) began an effort to model the dispersion of emissions from the incinerator stacks at the Ony x Environmental Services, Inc. (Onyx ) facility located in Sauget, Illinois. This effort was undertaken in order to gauge whether or not the hazardous waste incinerator requirements under the September 30, 1999 Maximum Achievable Control Technology (MACT) Rule (Federal Re gister Volume 64, page 52827 - 64 FR 52827) would be protective of public health and the environment in the surrounding community . U.S. EPA used dispersion models recommended in the Appendix W of Title 40 of the Code of Federal Regulations Part 51 (40 CFR Part 51) for the modeling effort and based the approach on that of the 1998 Draft Human Health Risk Assessment Protocol (Draft HHRAP) (U.S. EPA 1998). The results of this first round of modeling were used in preparing preliminary operating conditions f

or the incinerators under the facility’s draft RCRA permit which was provided to Ony x on June 5, 2003 (U.S. EPA 2003). In response to the draft conditions, Ony x commissioned its own dispersion modeling and submitted a report of such on September 8, 2004 ( Onyx2004). U.S. EPA reviewed Ony x’s dispersion modeling and found some aspects that were more appropriate for the site and some that were not supportable. Onyx responded by conducting additional stack testing in March of 2005, adding site - specific parti cle size distributions and mercury speciation for the rotary

kiln unit. Ony

x submitted updated modeling incorporating the new stack test results in May 2005 (Ony

x 2005a). In corporating appropriate modeling improvements from Onyx ’s modeling efforts and the results of the stack testing, U.S. EPA prepared a second round of dispersion modeling in May of 2005. The results were comparable to those generated by Ony x. In October 2005, Ony x submitted yet another version of the modeling differing significantly f rom earlier versions (Ony x 2005 c ). The differences were the result of updating the modeling to reflect the new HHRAP which had been finalized with several significant revisions in September of 2005 (U.S. EPA 2005). Ony x incorporated some of the revisions made to the HHRAP. In April 2006, U.S EPA incorporated recommendations of the finalized HHRAP guidance and appropriate inputs from Ony x’ s and U.S. EPA’s earlier modeling efforts and performed the dispersion modeling documented in this report for use in a ssessing impacts to public health and the environment in the vicinity of the facility

and for the development of operating conditions for the RCRA permit, if any .

### II - 1

**II. Facility** 

**Information** The Onyxfacility , located at #7 Mobile Avenue in Sauget, Illinois, is long and narrow and laid out from the southwest to the northeast on its longest transect (See Figure II - 1). Stacks 2 and 3 each serve fixed - hearth dual - chamber incinerators located on the northeastern end of the facility and Stack 4 serves a rotary kiln incinerator located on the southwestern end. The incinerators burn a variety

of hazardous wastes. The facility is located in the Mississippi River floodplain and is surrounded b y multiple ty pes of land use. Industrial and commercial businesses comprise the immediate vicinity

of the facility

with residential areas just over a mile away . Nearb y waterbodies include the Mississippi River to the west and Frank Holten State Park, which comprises two lakes to the east. The following stack information was subm itted by Onyxin its latest modeling report (Ony x 2005 c ). Parameter Stack 2 Stack 3 Stack 4 Source fixed - hearth dual - cham ber incinerators rotary kiln Coordinates* 745314.456m E 4275912.275m N 745342.392m E 4275958.041m N 744979.822m E 4275204.979m N Ba se Elevation 126.19 meters 126.19 meters 126.49 meters Stack Height 27.432 meters 27.432 meters 30.48 meters Stack Diameter 0.6858 meters 0.6858 meters 1.2192 meters Stack Gas Temperature 463  Kelvin 463  Kelvin 481  Kelvin Stack Gas Exit Velocity 20.2 meters/second 20.2 meters/second 20.4 meters/second Emission Rate** 1 gram/second 1 gram/second 1 gram/second 

### * The coordinates appear to be based on the Universal Transverse Mercatur (UTM) projection of the 1983 North American Datum (NAD83). ** 1 gram/second is an assumption called unit emission that simplifies modeling. Actual emission rates or regulatory limits can be applied to the results of modeling a unit emission rate after dispersion modeling.

### II - 2

### III - 1



## III. **Meteorological Dat a**  In November 2 000, U.S. EPA obtained and prepared five years of hourly meteorological data in the vicinity

of the Onyxfacility

for use in the dispersion modeling. A draft report describing the source data, input assumptions, and how the data was processed is included in Attachment 1. The report includes the original meteorological data processing as well as additional revisions to the meteorological processing made in May 2005. Ony x’ s consultant also prepared five ye ars of hourly meteorological data for use in disp ersion modeling. U.S EPA noted a number of differences between U.S. EPA’s original air modeling and that described in Ony x’s report. Attributes of Ony x’ s modeling that differed with U.S. EPA’s original approach, but were based on site - specific informatio n and consistent with the Draft HHRAP, were adopted by U.S. EPA for the dispersion modeling described herein. These instances will be described in detail in subsequent sections where appropriate. Ultimately , Onyx ’s meteorological data remained different from U.S. EPA’s data in several respects (for example, U.S EPA combined upper air data from Salem and Peoria, Illinois for the modeling while Onyxused data from Monett, Missouri). Before further investigating these differences, U.S. EPA tested the disp ersion model for sensitivity to the meteorological data b y running the dispersion model for a select group of sensitive receptors (primarily the lakes at Frank Holten State Park). U.S. EPA discovered that total deposition of particle bound or vapor contam inants did not significantly change between meteorological data files (See Table III - 1). Total deposition of vapor from all stacks combined averaged six percent higher using the Ony x meteorological data. Differences in total deposition of particle bound contaminants from Stack 4 between meteorological data files were less than one percent. The final dispersion modeling described herein was prepared using Onyx ’s meteorological data. **Table III**  **- 1**  **Deposition R ate Comparisons**  **– U.S. EPA Modeling with Varying Input Options**  Meteorological Data Source Particle Data

Source Total Particle Bound

Deposition

– All Stacks Total Vapor Deposition

– All Stacks Total Particle Bound

Deposition

– Stack 2 U.S. EPA Stack 4 0.00 681 0.0176 Onyx Stack 4 0.00680 0.0186 0.0024 Onyx U.S. EPA HHRAP 0.0012 Note: 1) All deposition values in grams/square meter/year 2) Deposition rates here are from provisional modeling runs and differ slightly from the final modeling run summari zed in the table at the end of the report. 

### A. **Anemometer Height** This is the height of the met station tower above the ground surface. The instrument tower at Lambert Field, St. L ouis, Missouri, station number 13994, for the period 1984 - 1989 was 6.096 meters (20ft) above the ground surface. Onyx ’s modeling initially used a value of 10 meters for the anemometer height, which corresponds to the current station height. However, at the time of the measurements used for the dispersion modeling, the height was 6. 096 meters. Subsequent meteorological data files prepared b y Onyx , including those used in the latest U.S. EPA modeling use the correct value.

### III - 2

**B. Surface Roughness Length at Measurement Site**  Surface roughness height

—also referred to as (aerody namic) surface roughness length

—is the height above the ground at which the wind speed goes to zero. Surface roughness affects the height above local ground level that a particle moves from the ambient air flow above the ground (for example in the plume) into a “captured” deposition region near the ground. That is, I SCST3 assumes the particle is deposited to the ground at some point above the actual land surface, based on surface roughness height. Surface roughness height is defined b y individual elements on the lands cape, such as trees and buildings. The surface roughness over a given area reflects man made and natural obstructions, and general surface features. The effective surface roughness length has been estimated for a number of surface conditions. U.S. EPA o riginall y used a value of 0.04, which was an average of all seasonal values for grassland to approximate an airport location. Ony

x proposed using 0.10 meters (corresponding to grassland during the summer) which the Final HHRAP recommends if you are using National Weather Service surface meteorological data. The final version of meteorological data used in the dispersion modeling used the Final HHRAP recommended value of 0.10 meters. **C. Surface Roughness Length at the Modeled Site**  The surface roughness length at the modeled site is a measure of how high above the ground surface particles in a plume will transition from plume flow to gravitational deposition. U.S. EPA originall y used a value of 1.0 meter corresponding to that of an urban area (Draft HHRAP). Ony x applied a more site - specific approach, following a Draft HHRAP recommendation to divide the area within 3 kilometers of the facility into a number of compass point directions and estimate an overall surface roughness based on surrounding land use and wind direction frequencies for each compass - point direction. In this manner, Ony x calculated a site - specific surface roughness length of 0.62 meters. U.S. EPA conducted an independent calculation using digital land use/land cover maps which were revised manuall y taking into account a 2002 aerial photo of the area available on the internet. U.S. EPA obtained the United States Geo logic Survey (USGS) land use/land cover map for St. Louis, Missouri from the <http://www. webgis.com > website. The 2002 aerial photo was obtained from the <http://www.terraserver.microsoft.com> website. The adjustment was made manuall y using graph paper to assign land use to the areas within a 3 - kilometer radius of the facility. Attachment 2 contains the figures and spreadsheet output of the calculation. U.S. EPA’s calculated site - specific surface roughness length of 0.60 meters was similar to that calculated by Ony x. The current modeling is based on Ony x’ s calculated value of 0.62 meters. **D. Minimum Monin**  **- Obukhov Length**  U.S. EPA originall y based this parameter (pertaining to atmospheric stability) at 50 meters for an urban area. Subsequently, U.S. EPA agreed to use the Onyxrecommended value, setting the minimum Monin - Obukhov L ength to 75 meters, the average value for compact residential/industrial and commercial (19 - 40 story) buildings.

### III - 3

**E. Noon Time Albedo**  Albedo (the fraction of incoming solar radiation reflected back into the atmosphere) is used in calculating the heat balance at the surf ace of the earth and is used to adjust the Monin - Obukhov Length on an hourl y basis. The noon time albedo is the value of albedo at midday . U.S. EPA originall y used a value of 0.18, corresponding to the average of all seasonal values for urban land use. Onyxapplied the approach used for site - specific surface roughness to noon time albedo for different land uses taken from Table 3 - 5, A lbedo of N atural Ground C overs for L and U se T ypes and S easons , in HHRAP. Inthis way , Ony x calculated a noon - time albedo of 0.22. U.S. EPA applied the same approach and estimated noon - time albedo at 0.26. Since the values are similar and the HHRAP indicates dispersion modeling results are not particularly sensitive to this parameter, U.S. EPA agreed to use the Onyx - suggest ed value of 0.22. A sensitivity analy sis conducted b y U.S. EPA Regi on 6 showed that variations in n oon time albedo had only slight impacts on dry

deposition and no effect on air concentrations or wet deposition (U.S. EPA 1997) **F. Bowen Ratio**  The Bowen ratio is the ratio of the sensible heat flux to the evaporative or latent heat flux at the ground surface. U.S. EPA initially used a Bowen ratio of 1.625 (an average of all seasonal values for an urban area). The HHRAP recommends a Bowen ratio of 2.0 for urban areas where annual rainfall exceeds 20 inches. Onyxused a value of 2.0 and the meteorological data used for the current modeling uses this value. The sensitivity anal ys is conducted by U.S. EPA Region 6 showed that variations in Bowen ratio had onl y sl ight impacts on dry deposition and no effect on air concentrations or wet deposition (U.S. EPA 1997). **G. Fraction of Net Radiation Absorbed at the Ground**  Also used for calculating hourly values of Monin - Obukhov length, fraction of net radiation absorbed at the ground is the last component of radiative heat balance. U.S. EPA and Ony x both used a value of 0.27 for urban areas, as recommended by HHRAP. The U.S. EPA sensitivity anal ys is showed that dispersion modeling results were unaffected b y variations in th e fraction of net radiation absorbed at the ground (U.S. EPA 1997). **H. Anthropogenic Heat Flux**  Anthropogenic heat is the surface heating caused by human activity , including automobiles and heating s ys tems. It is used to calculate hourl y L values (Monin - Obuk hov lengths). The HHRAP gives a table of values of anthropogenic heat flux for a variety of cities around the world. U.S EPA originall y applied a linear regression to all the cities in the table located between 34 and 64 North latitude assuming that anthropogenic heat flux was dependent on population density . Using the population density for St. Louis (177 person/square kilometer), U.S. EPA calculated a value of 5 Watts/square meter for anthropogenic heat flux. Onyx used a value of 20 Watts/square meter which is also consistent with the HHRAP recommendation for large urban areas. The current modeling used the HHRAP recommended value of 20 Watts/square meter. The U.S. EPA sensitivity anal ys is showed that dispersion modeling results were unaffected b y variations in anthropogenic heat flux (U.S. EPA 1997).

### III - 4

**I. Incoming Solar Radiation and Leaf Area Index**  In coming solar radiation and leaf area index are used by the dispersion model to calculate a varying dry

vapor deposition velocity , a key parameter for evaluating dry vapor deposition. The latest version of HHRAP recommends evaluating dry vapor deposition for mercury using the TOXICS model option in the dispersion model. The option allows the user to enter a constant dry vapor deposition velocity or let the m odel perform complex calculations to derive the velocity . Even though U.S EPA and Ony x both used a constant dry vapor deposition velocity , as recommended in HHRAP, the meteorological data file must be formatted to include columns for incoming solar radiation and leaf area index or the TOXICS model option for dry vapor deposition will not run. For all model runs calculating dry vapor deposition, two additional columns of blank or zero values were added to the final processed meteorological data file. **J. Pre**  **- p**  **rocessed Meteorological File** The surface weather data from the National Weather Service weather station at Lambert Field, St. Louis, Missouri was combined by Onyxwith upper air data from Monett, Missouri and the parameters above in order to create one co mbined pre - processed data file. Ony x did so for each of five ye ars and ultimately performed five individual sets of dispersion modeling. Jeff Sprague, of the Illinois Environmental Protection Agency (IEPA), combined Ony

x’s yearly meteorological files into one concatenated file for a 5 - year period. This file was used in the current version of dispersion modeling with the exception of the vapor runs wherein placeholder columns were added for incoming solar radiation and leaf area index.

### IV - 1



## IV. **St udy** 

**Ar ea**  **A. Recept** **or Grid** U.S. EPA modeled dispersion of stack emissions over a 20 kilometer b y 20 kilometer area (just over 154 square miles) surrounding the facility . Receptor locations were defined every 100 meters to a distance of four kilometers from the center of the facility (a point set halfway between Stacks 2 - 3 and Stack 4). Additional receptors were defined every 500 meters to a distance of 10 kilometers from the facility . See Figure IV - 1 for the receptor grid.

### IV - 2

The receptor grid was prepared using AERMOD - Vi ew version 5.1, a windows - based interface for running U.S.EPA approved dispersion models developed b y Lakes Environmental Software of Waterloo, Ontario. **B. Terrain**  Elevated terrain in the vicinity of the stacks can have a significant impact on the results of air modeling. Onyx ’s stacks are located on Mississippi River bottomland with nearby bluffs rising as much as 150 feet (44 meters) above the top of Ony x’ s highest stack. In order to properl y handle terrain effects, each receptor point must have a corre sponding elevation. USGS 7.5 Minute Digital Elevation Models (DEMs) with 30 x 30 meter samples (of elevation) were used to obtain the elevations and were already available on the Agency’s server. The following specific DEMs were used: Cahokia, IL; Clay ton, MO; French Village, IL; Granite City, IL ; Monks Mound, IL; and Webster Grove, IL. The Clay ton, French Village, and Monks Mound DEMs were found to be in a different projection than the default projection selected for the modeling (NAD83). U.S. EPA used ARCGI S version 8.3 (a computer based Geographical Information System

– GI S

– developed b y ESRI of Redlands, California) to convert the DEMs from the 1927 North American Datum (NAD27) to NAD83. ARCGIS was also used to ensure that elevation values in the DEMs were in the same units (meters). The DEMs were sampled in ARCGI S to derive an elevation for each receptor point. The UTM coordinates of the receptor grid points were combined with their respective elevations into a text file which was used to imp ort elevations into the dispersion model. See Figure IV - 2 for elevations in meters within the receptor grid.

### IV - 3

### V - 1



## V. **Dispersion Modeling** U.S. EPA used the Industrial Source Complex

– Short Term model, Version 3 (I SCST3) to model dispersion of stack emissions from the Onyx facility. IS CST3 is a steady- state Gaussian plume model which can be used to assess pollutant concentrations and/or deposition fluxes from a wide variety

of sources associated with an industrial source complex. The model was embedded within AERMOD - View which was used for the current modeling runs. **A. Partitioning of Pollutant into Different Phases**  Hazardous constituents are assumed to be emitted and dispersed from the stack in three different way s. Volatile contaminants are expected to be em itted in the vapor phase. Some non - volatile contaminants are expected to be emitted as particles and others are expected to be emitted while absorbed onto the surface of particles (known as particle - bound). The three types of emissions were modeled assum ing a unit emission rate (1 gram/second). The dispersion results were scaled to reflect actual emissions or regulatory limits as part of the risk assessment. **B. Particle Emissions**  U.S. EPA selected the following model options to model particle emissions: w et deposition (particles brought to the ground b y precipitation); dry deposition (particles fall to the ground by gravity); total deposition (wet and dry added together); and wet and dry

plume depletion (deposited particles are subtracted from the plume m ass). In order to run these options, I SCST3 requires a particle size distribution of stack particles and and an estimate of their density . In March of 2005, Ony x conducted stack testing on the rotary kiln and stack 4 for particle size distribution. Stacks 2 and 3 , however, were not tested. On October 14, 2005, Onyxsubmitted a detailed rationale for applying the stack 4 particle data to stacks 2 and 3 based on similarities in air pollution control sy stems (Ony x 2005b ) . U.S. EPA ultimately

used the particle data from the stack 4 test in part because it resulted in more conservative particle bound deposition (see V.C. below). The following table of particle data is from the October 2005 Ony x Report:

### V - 2

**Table V**  **- 1**  **Onyx Environmental Services Rotary Kiln and Fixed Hearth Incinerators Hum an Health Risk**  **Assessment Report, October 2005, Franklin Engineering Group, Inc.** 

### C. **Particle Bound Emissions** U.S. EPA selected the same modeling options for the particle bound emissions as were selected for particle emissions: wet deposition (particles brought to the ground b y precipitation); dry deposition (particles fall to the ground by gravity); total deposition (wet and dry added together); and wet and dry

plume depletion (deposited particles are subtracted from the plume mass). The amount of a particle bound pollutant present on a given particle is assumed to be directl y proportional to surface area since the contaminant is absorbed to the surface. In order to account fo r this, HHRAP recommends that the particle size distribution be adjusted for relative particle surface area assuming the particles are spherical. The column in Table V - 1 labeled Fraction of Total Surface Area is based on this adjustment and is entered as the mass fraction for particle bound contaminants. Based on the March 2005 stack 4 sampling and analy sis for particle size distribution and mercury speciation and the detailed rationale submitted in October, Ony x recommended applying the stack 4 particle data to stacks 2 and 3. U.S. EPA believes there are still too many differences in the design and operation of the incinerators (rotary kiln versus dual - chamber/fixed hearth for example) to completely accept this rationale. U.S. EPA tested stack 2 and 3 particle bound deposition results using stack 4 particle data and an example of particle data from HHRAP consistent with combustion facilities equipped with either electrostatic precipitators or

### V - 3

fabric filters. The site - specific particle size distribution (adjusted for surface area) from stack 4 resulted in higher total deposition rates at the Lakes at Frank Holten State Park (the critical receptor location for mercury emissions) than the example particle size distribution in HHRAP. In the absence of stac k - specific data for stacks 2 and 3, U.S. EPA used the particle data which resulted in higher deposition at the lakes, the stack 4 data, for the current round of modeling. **D. Vapor Emissions**  U.S. EPA originall y modeled only wet deposition of vapor. The finalized HHRAP included a protocol for modeling dry deposition as well. The new protocol, using the TOXICS model option in I SCST3, is run with some chemical specific data. Since mercury emissions are the primary concern and no other volatile emissions were risk drivers, the new dry vapor deposition modeling was focused on emissions of divalent mercury vapor. To run the model, HHRAP recommends that a constant dry vapor deposition velocity be entered. According to HHRAP, a default value of 2.9 centimeters/ second for divalent mercury can be used. U.S. EPA found the approach acceptable and attempted to model dry vapor deposition based on input files prepared by Onyx . It was discovered that these files contained a unit error. ISCST3 requires that the deposi tion velocity

be entered in meters/second whereas the guidance refers to centimeters/second. The Ony x input files were prepared with a value of 2.9 as opposed to the correct value of 0.029. U.S. EPA made the correction for this round of modeling. The co rrection resulted in a decrease of vapor deposition at the Lakes of Frank Holten State Park. U.S. EPA attempted to evaluate possible site specific dry vapor deposition velocities, however, it became apparent that the default value would be slightly more c onservative and U.S. EPA retained the Onyxsuggested value of 2.9 centimeters/second (entered as 0.029 meters/second). **E. Dispersion Coefficients**  ISCST3 requires the user select rural or urban dispersion coefficients. HHRAP recommends that the selection be based on surrounding land use. Urban land use is typicall y defined b y land use that has less than 35% vegetative cover. Many different land use types are then divided into urban and rural on this basis. As recommended by HHRAP, the surrounding land use is considered urban if it is greater than 50% of the total. Ony x conducted this procedure and concluded that the land use was close to 50% urban, making it difficult to assign the dispersion coefficients. Onyxagreed to evaluate both conditions for all o f its modeling runs. U.S. EPA independentl y conducted a similar anal ys is and concluded the area was urban (57%). U.S. EPA further reviewed the land use upwind of the stacks from the perspective of the Lakes at Frank Holten State Park. For the purpose of dispersion coefficients, and other parameters that influence the wind profile, it is recommended that the upwind fetch be used to determine the value, especially

for elevated sources like stacks. Essentially , the plume behavior is assumed to be more dependent upon the profile of the wind arriving at the stack from upwind so the upwind land use is used for these determinations. U.S. EPA determined that the upwind land use (to the west) was decidedl y urban. Therefore, the current modeling runs were based on urban dispersion coefficients.

### V - 4

**F. Input and Output**  As stated previousl y, U.S. EPA prepared the modeling input files based on those provided b y Ony x. A new receptor grid was generated and terrain was reimported. The only other change was the correction of the dry vapor deposition velocity as described in V.D. above. The model generated 1 - hour and annual plotfiles for air concentration, wet deposition, dry deposition, and total deposition each for vapor, particle and particle bound. The files are includ ed on a CD in attachment 3. The following table demonstrates the changes in air concentration and deposition estimates as the modeling was revised and corrected over time. The results are focused on the lakes and Frank Holten State Park since the risk as sessment was most sensitive to mercury impacts through contaminated fish consumption.

### V - 1

Average Annual Air Concentrations and Deposition Fluxes for 11 locations over the 2 lakes at Frank Holten State Park. Modeling Date Stack 4 Stack 2 or 3 α Particle - Bound Vapor Particle - Bound Vapor Air Concentration (μg/m3 ) Total

Deposition (g/m 2 /y r) Air Concentration (μg/m3 ) Total

Deposition (g/m 2 /y r) Air Concentration (μg/m3 ) Total

Deposition (g/m 2 /y r) Air Concentration (μg/m3 ) Total

Deposition (g/m 2 /y r) January 200 1 0.013 0.0013 0.0133 0.00035 0.009 0.00585 0.01122 0.00052 June 2005 0.0089 0.0023 0.0094 0.00042 0.0106 0.0016 0.011 0.00048 October 2005 0.0104 β 0.00250 β 0.01077 0.00047 0.0104 γ 0.00156 γ April 2006 0.0096 0.0021 0.0062 0.0058 0.0111 0. 00246 0.00694 0.0065 α results from stacks 2 and 3 are considered comparable because each serve nearly identically designed and operated incinerator s and are located only

54 meters apart β based on stack 4 particle data γ based on HHRAP example particle data

### VI - 1



## VI. **References** Ony x, 2004, Onyx Environmental Services Rotary Kiln and Fixed Hearth Incinerators, Screening Level Human Health Risk Assessment Report , Ony x Environmental Services, In c., September 8. Ony x, 2005a, Onyx Environmental Services Rotar y Kiln and Fixed Hearth Incinerators, Screening Level Human Health Risk Assessment Report , Ony x Environmental Services, In c., May . Ony x, 2005b, Correspondence with T. Ramal y, U.S. EPA via electronic mail with attached document Determination of Appropriate Particle Size Distribution and Mercury Speciation to be Utilized for the Fixed Hearth and Rotary Kiln Incinerators , David Klarich, OnyxEnvironmental Services, Inc., October 14. Ony x, 2005 c , Onyx Environmental Services Rotary Kiln and Fixed Hearth Inc inerators, Screening Level Human Health Risk Assessment Report-Revised, Ony x Environmental Services, Inc., October 27. U.S. EPA, 1997, Model Parameter Sensitivity Analysis , U.S. EPA Region 6 Center for Combustion Science and Engineering, Dallas, Texas, May 23. U.S. EPA, 1998 , Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities , Peer Review Draft, Office of Solid Waste and Emergency Response, EPA530 - D - 98 - 001A, July . U.S. EPA, 2003, L etter to Ony x with attached draft permit, U.S. EPA, R5, Waste Management Branch, June 5. U.S. EPA, 2005 , Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities , Office of Solid Waste and Emergency Response, EPA530 - R - 05 - 006, September.

### Attachment 1 TWI - incinerator, Sauget, Illinois Air Modeling

### 2 TWI - incinerator, Sauget, Illinois Air Modeling Creating met data files for TWI **April 2000** Downloaded Samson files for St. Louis (Lambert Field) for 1985 - 1989 Stl - 85.dat Stl - 86.dat Stl - 87.dat Stl - 88. dat Stl - 89.dat Downloaded SCRAM upper air files from Salem, Illinois for 1985 - 1987 03879 - 85.txt 03879 - 86.txt 03879 - 87.txt Downloaded SCRAM upper air files from Peoria, Greater Peoria Airport for 1988 - 1989 14842 - 88.txt 14842 - 89.txt **November 2000** 1) Fill ed in missing data point in Stl - 85.dat - new file Stl - 85A.dat 5/19/85 0600hrs - missing dew point - extrapolated 0400 - 0700hrs - 10.0  C 2) Prepared TWI85.met file using RAMMET -View using Stl - 85A.dat and 03879 - 85.txt Options for wet deposition: anemometer height = 6.096m Monin - Obukhov length = 50m (urban) Surface Roughness Length (measurement site) = 0.04m (average of all seasonal grass land values to approximate an airport) Surface Roughness Length (application site) = 1.00m (urban) Noon -time Albedo = 0.18 (average of all seasonal urban values) Bowen Ratio = 1.625 (average of all seasonal urban values under average conditions) Anthropoge nic Heat Flux = 5 W/m2 (linear regression of population density vs. flux for locations of mid to high latitudes) The St. Louis metropolitan area has a population reported by the U.S. Census Bureau of 2,444,099 and a population density of 177 persons per k m2 . The population density was input to a linear regression of the flux and population density values provided as examples. Hong Kong

### 3

and Singapore were not used as they appeared to be outliers in this comparison. The remaining dataset comprised cities within 34 to 64 N latitude. Fraction of Net Radiation Absorbed at Ground = 0.27 (urban) 3) Filled in missing data points in Stl - 86.dat - new file Stl - 86A.dat 2/1/86 0100hrs - missing ceiling height - extrapolated 2400 - 0200hrs - 1145m 2/22/86 1300hrs - miss ing ceiling height - extrapolated 1100 - 1500hrs - 77777m 4) Prepared TWI86.met file using RAMMET -View using Stl - 86A.dat and 03879 - 86.txt. Same options for wet deposition as for 1985. 5) Filled in missing data points in Stl - 87.dat - new file Stl - 87B.dat 12/30/87 2400hrs - 12/31/87 2400hrs - missing wind speed and wind direction - extrapolated linearly from 12/30/87 1100hrs - 1/1/88 1200hrs (no other pattern, daily or otherwise apparent) 12/31/87 2400hrs - missing dew point - extrapolated 12/29/87 - 1/2/88 - 9. 5  C 12/31/87 2400hrs - missing visibility - extrapolated 2300hrs - 1/1/88 0100hrs - 24.1 km 12/31/87 2400hrs - missing ceiling height - extrapolated 2300hrs - 1/1/88 0200hrs - 77777m 6) Prepared TWI87.met file using RAMMET -View using Stl - 87B.dat and 03879 - 8 7.txt. Same options for wet deposition as for 1985. 7) Filled in missing data points in Stl - 88.dat - new file Stl - 88A.dat 12/31/88 2400hrs - missing wind direction - extrapolated 2000hrs - 1/1/89 0300hrs - 298  12/31/88 2400hrs - missing wind speed - extrapolated 2100hrs - 1/1/89 0300hrs - 2.5m/s 12/31/88 2400hrs - missing dew point - extrapolated 2300hrs - 1/1/89 0100hrs - 0.9  C 12/31/88 2400hrs - missing visibility - extrapolated (logarithmic) 2000hrs - 1/1/88 0400hrs - 2.6 km 12/31/88 2400hrs - missing ceiling height - extrapolated 2000 - 2300hrs - 90m (low ceiling gave way quickly to clear skies by 0100 1/1/89. . . couldn’t extrapolate. Other trends in weather data seemed to indicate that the weather change happened after 2400 based on visually examining graphs of the data, therefore, the clearing sky was also assumed to happen after 2400hrs) 8) Prepared TWI88.met file using RAMMET -View using Stl - 88A.dat and 14842 - 88.txt. Same options for wet deposition as for 1985. 9) Filled in missing data points in Stl - 89.dat - new file Stl - 89A.dat 12/31/89 2400hrs - missing wind direction - extrapolated 1900 - 2300hrs - 237  12/31/89 2400hrs - missing wind speed - extrapolated 1900 - 2300hrs - 3.5m/s 12/31/89 2400hrs - missing dew point - extrapolated 1900 - 2300hrs - - 1.9  C 12/31/89 2400hrs - missing visibility - set equal to 2300hrs (no trend noticed) - 24.1 km 12/31/89 2400hrs - missing ceiling height - extrapolated 1900 - 2300hrs - 1349m 10) Prepared TWI89.met file using RAMMET -View using Stl - 89A.dat and 14842 - 89.txt. Same o ptions for wet deposition as for 1985. 11) Re -prepared met files for 1988 and 1989 changing the station location number in the upper air files from Greater Peoria Airport, Peoria, Illinois to match the Salem, Illinois upper air files. RAMMET -View would not combine the five years into one file if the same upper air stations hadn’t been used throughout. Upper air files 14842 - 88.txt and 14842 - 89.txt were changed to

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03879A88.txt and 03879A89.txt, respectively. 12) A five - year met file, TWI85 - 89.met, was created by a RAMMET -View utility from TWI85.met, TWI 86.met, TWI87.met, TWI88A.met, and TWI89A.met. May 2005 Based on information provided by Onyx/TWI, including more site specific met processing information, the MET data was updated for new modeling runs. The met data was reviewed again for missing data and re -processed with the following parameters changed from those originally used in step 2) from November 2000 above: Monin - Obukhov length was changed from 50m (urban) to 75m (average of urban - 50m and commercial - 100m) Surface Roughness Length (measurement site) was changed from 0.04m (average of all seasonal grassland values to approximate an airport) to 0.10m (HHRAP recommendation for airports) Surface Roughness Length (application site) was changed from 1.00m (urban) to 0.62m based on surrounding land use (Onyx/TWI referred to HHRAP methodology). Noon -time Albedo was changed from 0.18 (average of all seasonal urban values) to 0.22 based on surrounding land use (Onyx/TWI referred to HHRAP methodology). Bowen Ratio was changed from 1.625 (average of all seasonal urban values under average conditions) to 2.0 (Onyx/TWI referred to HHRAP methodology). Anthropogenic Heat Flux was changed from 5 W/m 2 (linear regression of population density vs. flux for locations of mid to high latitudes) to 20 W/m 2 (HHRAP default for urban areas). 1) Surface and upper air data for 1985, Stl - 85.dat and 03879 - 85.txt, were checked for missing data using using Rammet -View version 4.8, a Meteorological Pre - Processor developed by Lakes Environmental Software of Waterloo, Ontario. The met files were checked for missing data using Rammet View’s “grid -preview” feature. The “grid -preview” feature allows the user to review the data and sort the columns numerically, so that blanks or a f ield of nines (commonly used to designate missing data) could be identified. Missing data was identified and remedied as follows (in accordance with Procedures for Substituting Values for Missing NWS Meteorological Data for Use in Regulatory Air Quality M odels , Atkinson, Dennis, and Russell F. Lee, July 7, 1992). No critical missing data were identified. The surface and upper air files for 1985 were combined into combined met file <NewTWI85.met>. 2) Surface and upper air data for 1986, Stl - 86.dat and 0387 9 - 86.txt were checked for missing data in the same manner and two data points were missing. Ceiling height for 0100hrs, 2/1/86 was filled in with the ceiling height from the preceding hour, 1,070m, since cloud cover was greater than nine tenths. Ceiling height for 1300hrs, 2/22/86 was filled in with the ceiling height representing unlimited ceiling, 77,777m, since cloud cover was less than five tenths. The updated surface file was labeled <Stl - 86B.dat> and the combined processed met file <NewTWI86.met> w as generated from the surface and upper air files. 3) All wind speeds and wind directions on 12/31/87 were missing from the surface data file. U.S. EPA decided to try to find another complete year rather than try to fill in so many missing hours.

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Accordin gly U.S. EPA downloaded the Samson file, <13994_84.sam>, already converted to ASCII format, from the WebMet web site <http://www.webmet.com/> for the St. Louis (Lambert Field) Airport, station number 13994 for 1984. U.S. EPA obtained the upper air file, <14842 - 84.txt> from the WebMet web site <http://www.webmet.com/> for the Greater Peoria Airport, Peoria, Illinois, station number 14842 for 1984 since the Salem site data was li mited to 1985 through 1987. A check using Rammet -View revealed no missing critical data from either file. All station information within the Peoria upper air file were changed to match the station ID at Salem, Illinois in order to avoid problems when com bining the whole 5 years of met data. The upper air file was also renamed <03879A84.txt> and was combined with <13994_84.sam> into the processed file <NewTWI84.met>. 4) Missing data for 1988 was filled in the same manner as originally described above excep t that the ceiling height for 2400 hrs, 12/31/88 was filled in with the ceiling height from the preceding hour since cloud cover was greater than nine tenths. The updated surface file was labeled <Stl 88B.dat> and the combined processed met file <NewTWI88 .met> was generated from the surface and upper air files. Note, the upper air file for 1988 was for data collected at the Greater Peoria Airport, Peoria, Illinois, station number 14842 since the Salem site data was limited to 1985 through 1987. All stati on information within the Peoria upper air file were changed to match the station ID at Salem, Illinois in order to avoid problems when combining the whole 5 years of met data. The upper air file was also renamed <03879A88.txt> before being processed with the surface file. 5) The existing missing data remedies completed for the 1989 files completed in November 2000 were retained as is. A new met file <NewTWI89.met> was generated from the updated files <Stl - 89A.dat> and <03879A89.txt>. Note that the upper air data was collected at the Greater Peoria Airport, Peoria, Illinois, station number 14842, since the Salem site data was limited to 1985 through 1987. All station information within the Peoria upper air file were changed to match the station ID at Salem, Illinois in order to avoid problems when combining the whole 5 years of met data. 6) The processed met data from 1984, 1985, 1986, 1988, and 1989 were combined into one 5 - year file, <TWI8489.met>.

### Attachment 2 Independent Calculation of Si te - Specific Surface Roughness Length

Figures and Spreadsheet

### 2 **Title: Land Use/Land Cover** 

### Legend: pink urban, commercial, or industrial areas

ye llow agricultural blue water green striped wetland green deciduous forest brown barren land

### 3

2002 Urban Areas Aerial Photo from < http://www.terraserver.microsoft.com>

### 4

Modified land use/land cover based on 2002 aerial photo and superimposed with a 3 - kilometer radius circle divided into 16 compass point directions.

### 5

Onyx/TWI Surface Roughness, Noon Time Albedo Using Land Use/Land Cover updated by Urban Areas Aerial Photo surface roughness annual

average http://www.terraserver.microsoft.com urban 1 barren land 0.2625 as desert 0.161 deciduous forest 0.9 wetlan d 0.1625 39.174 blocks per slice 0.04025 confirerous forest 1.3 water 0.0001 agricultural land 0.0725 grassland 0.04025 compass point urban

blocks percent forest blocks percent agricultural blocks per cent wetland blocks percent barren percent water blocks percent grassland percent total Com pass Point Wind

Frequency Com pass Point direction Surface Roughness (blowing

from) Surface

Roughness We ighted for Wind Frequ ency N 14 35.74% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 18 45.95% 7.174 18.31% 39.174 0.36 4.09% 0.0149 NNE 13.67 34.90% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 25.504 65.10% 39.174 0.38 3.62% 0.0136 NE 31.17 79.57% 0 0.00% 1 2.55% 0 0.00% 0 0.00% 0 0.00 % 7.004 17.88% 39.174 0.80 3.67% 0.0296 ENE 29.174 74.47% 0 0.00% 1 2.55% 0 0.00% 0 0.00% 0 0.00% 9 22.97% 39.174 0.76 3.03% 0.0229 E 17.924 45.75% 0 0.00% 0.25 0.64% 0 0.00% 0 0.00% 1 2.55% 20 51.05% 39.174 0.48 4.12% 0.0197 ESE 12.174 31.08% 0 0 .00% 17.5 44.67% 0 0.00% 0 0.00% 0 0.00% 9.5 24.25% 39.174 0.35 6.39% 0.0225 SE 14.674 37.46% 0 0.00% 12.5 31.91% 0 0.00% 0 0.00% 0 0.00% 12 30.63% 39.174 0.41 7.36% 0.0302 SSE 28.674 73.20% 0 0.00% 5 12.76% 0 0.00% 0 0.00% 0 0.00% 5.5 14.04% 39.174 0.75 7.85% 0.0586 S 26.174 66.81% 0 0.00% 13 33.19% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 39.174 0.69 10.06% 0.0696 SSW 9.674 24.69% 0 0.00% 27.5 70.20% 2 5.11% 0 0.00% 0 0.00% 0 0.00% 39.174 0.31 5.21% 0.0160 SW 8.174 20.87% 5 12.76% 8 20.42% 9 22.97% 0 0.00% 9 22.97% 0 0.00% 39.174 0.38 5.54% 0.0208 WSW 22.174 56.60% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 17 43.40% 0 0.00% 39.174 0.57 6.77% 0.0383 W 34.424 87.87% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 4.5 11.49% 0.25 0.64% 39.174 0.88 6.63% 0.0583 WN W 34.42 4 87.87% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 4 10.21% 0.75 1.91% 39.174 0.88 9.23% 0.0812 NW 34.424 87.87% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 4 10.21% 0.75 1.91% 39.174 0.88 7.30% 0.0642 NNW 32.174 82.13% 0 0.00% 0 0.00% 0 0.00% 0 0.00% 6 15.32% 1 2.55% 39. 174 0.82 4.55% 0.0375 95.42% 363.102 57.93% 5 0.80% 85.75 13.68% 11 1.75% 0 0.00% 63.5 10.13% 98.432 15.70% 626.784 0.598 meters total blocks wind frequency weighted surface roughness

### Attachment 3 Air Modeling Files

– Electronic Format