MDE

Prepared by

The Maryland Department of the Environment

Air and Radiation Management Administration

1800 Washington Blvd.

Baltimore, Maryland 21230-1720

April 2009
Air Quality Analysis Objectives 2

Section A 3

PM10 Emissions Scenario 3

Section B 3

Stack Parameters and Emission Rates 3

Land Use Classification 3Receptor Grid/Terrain Elevations 4

Good Engineering Practice Stack Height Analyses

Meteorological Data 5Background Air Quality Data 8Dispersion Model Selection/Options 8

Section C 9

Modeling Results/NAAQS Analysis 9

SectionD 9

Conclusion/Analysis Findings 9

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The Severstal Sparrows Point Sintering Plant is the one sintering plant affected by this proposed

SIP revision and is currently controlled with two water scrubbers each having two fans. TheSeverstal Sparrows Point Sintering Plant was initially subject to visible emissions and particulate

matter requirements; however, the configuration ofthe side-by-side scrubbers for this particular

plant causes it to be difficult to demonstrate compliance with visible emissions requirements

using the method 9 observational procedures. The heavy steam plumes from the scrubbers areusually combined making it difficult to observe any residual plume. Stack tests, however, have

demonstrated that the particulate matter emissions are always well within the 0.03 grain loading

requirement for particulate matter. The Department, in 2007, amended the regulation to exempt

the Severstal Sparrows Point Sintering Plant from the visible emissions requirement and

established open ended requirements for the scrubber pressure drop and water flow rate. This

SIP revision will include specific limits for the scrubber pressure drop and water flow rate.

The air quality modeling impact analysis will be based on a PM10 emission rate that corresponds

to the Sintering Plant’s maximum grain loading of 0.03 gr/dscf. The method used to calculatethe PM10 emission rate was based on stack test data, where 0.0285gr/dscf corresponded to a

PM10 emission rate of 133.16 lbs/hr (16.8 g/sec).

Air Quality Analysis Objectives

The air quality impact analysis was to accomplish the following objectives:

A. Determine PM10 emissions used for modeling.B. Provide the following: stack parameters, land use classification, the receptor grid and

terrain elevations, a Good Engineering Practice (GEP) stack height analyses, themeteorological data, background air quality and a description ofthe model/optionsused in the analysis.

C. Demonstrate that this proposed SIP revision will not cause or contribute to a violation

ofthe PM10 NAAQS.

D. Conclusion/Analysis offindings.

C

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equal to a PM10 emission rate of 133.16 lbs/hr (16.8 grams/second). This emission rate was used

for both stacks in the dispersion modeling analysis.

Section BStack Parameters and Emission Rates

The Severstal Sparrows Point Sintering Plant has two scrubber stacks (north stack and south

stack). The north stack was made the center ofthe grid for modeling purposes. The method

used to calculate the PM10 emission rate for dispersion modeling purposes was described

previously in Section A.

The PM10 emission rates and stack parameters used in dispersion modeling are presented inTable B-i.

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TABLE B-I. Sintering Plant PM10 Emission Rates and Stack Parameters

PM10 Stack Coordinates

Emission Base Stack Exit Stack Exit

Rate X y Elevation Height Diameter Temperature Velocity

Stack (glsec) (m) (m) (m) (m) (m) (K) (mis)

Ni 16.8 372782.08 4341504.00 4.08 47.24 5.0 310.65 14.33

51 16.8 372781.48 4341483.65 4.48 47.24 5.0 310.65 14.33

Land Use Classification

The Severstal Sparrows Point Sintering Plant is located in an area that is categorized as urban

based on the land use procedures described in section 8.2.8 ofthe U.S. EPA “Guideline on Air

Quality Models (Revised)” dated July 1986 and Auer, A.H. “Correlation of Land Use and Cover

with Meteorological Anomalies”, Journal of Applied Meteorology, Volumel7, May 1978. The

percentage of land falling into one of five land use types (11, 12, Cl, R2, R3) within a threekilometer circle around the power plant was subjectively determined using Land Use/Land Covermap. By inspection, it was determined that over 50 percent ofthe area was urban in nature.Thus, urban dispersion modeling coefficients and wind profile exponents were used in thedispersion modeling analysis.

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Receptor Grid/Terrain ElevationsA Cartesian receptor grid consisting of 1,703 receptors were used for this dispersion modelinganalysis. The Cartesian receptor grid consisted on the following sub grids:

. Fence line:

- Evenly spaced receptors 50 meters apart placed along the property line.

• Fence line to 2 kilometers:

- Evenly spaced receptors using 100 meter incremental spacing.

• 2 — 5 kilometers:

- Evenly spaced receptors using 500 meter increment spacing.

Terrain elevations were calculated for each ofthe discrete receptors using 7.5 —minute DEM filesas input into the AERMAP program.

Figure B-i. Land Use/Land Cover within 3 Kilometers of the Severstal

Sparrows Point Sintering Plant

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considered to extend five times the lesser ofthe structure

s height or width. A GEP stack height

is determined for each nearby structure by the following formula:

HgH+ 1.5L

Where:

Hg is the GEP stack heightH is the structure height

L is the structure’s lesser dimension (height or width)

All buildings that were large enough and close enough to influence the Severstal Sparrows Point

Sintering Plant stacks were considered in the GEP analyses. To perform this analysis and ensure

all EPA requirements were properly implemented, commercially available software from LakesEnvironmental was used. The Lakes Environmental BPIP provided an input file containing 36direction-specific building heights and widths for direct input into the dispersion model.

Both of the Severstal Sparrows Point Sintering Plant stack heights are 155 feet (47.24 meters)and are thus shorter than 213 feet (65 meters) so for dispersion modeling purposes both stacksare shorter than GEP and subject to downwash and were modeled with the appropriate BPIPstructure parameters.

Meteorological DataThe meteorological data selected for this air quality analysis consisted of surface data from

Baltimore-Washington International Thurgood Marshall Airport (BWI) and upper air data from

Sterling, VA. BWI is located approximately 17 kilometers (11 miles) away in Linthicum, MD

and Sterling, VA is located approximately 90 kilometers (56 miles) away. The five-year periodof 1986-1990 was used for the dispersion modeling analyses. This five-year period was chosen

because it was the most recent readily available data. The data was processed using the Aermet

program.

Prior to using the BWI surface meteorological data an analysis was completed, which compared

the Severstal Sparrows Point Sintering Plant’s surface characteristics with those of BWI to

determine ifthe BWI meteorological data could be used in this modeling analysis. This analysis

was completed using the AERSURFACE program, this EPA tool is used for determiningrealistic and reproducible surface characteristic values (i.e., Albedo, Bowen Ration and Surface

Roughness). The results ofthe 12 sector analysis are presented in Table B-2.

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2 30-60 0.16 0.12 0.76 0.22 0.019 0.7053 60-90 0.16 0.12 0.76 0.22 0.017 0.310

4 90-120 0.16 0.12 0.76 0.22 0.044 0.662

5 120-150 0.16 0.12 0.76 0.22 0.031 0.480

6 150-180 0.16 0.12 0.76 0.22 0.165 0.2567 180-210 0.16 0.12 0.76 0.22 0.642 0.230

8 210-240 0.16 0.12 0.76 0.22 0.356 0.076

9 240-270 0.16 0.12 0.76 0.22 0.325 0.026

10 270-300 0.16 0.12 0.76 0.22 0.050 0.418

11 300-330 0.16 0.12 0.76 0.22 0.025 0.615

12 330-360 0.16 0.12 0.76 0.22 0.420 0.767

According to the AERMOD Implementation Guide, ifland cover varies significantly by

direction, then surface roughness should be determined based on a sector. Based on the wind

rose (see Figure B-2) developed with 1986 -1990 BWI data the wind direction is predominately

from the western direction.

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TABLE B-3. AERSURFACE Surface Roughness Comparison Using a 90

Sector Centered on

Due West

I Location Sector Surface Roughness

BWI I I 0.113 N 225-315 Plant 0.102

Background Air Quality Data

PM10 ambient air quality background data was obtained from MDE’s Southeast Police StationPM10 monitor, which is located approximately 11 kilometers (7 miles) away from the Severstal

Sparrows Point Sintering Plant. The Southeast Police Station monitor was the closest PM10

monitor to the Severstal Sparrows Point Sintering Plant and was also considered representativeofthe area.

The Southeast Police Station PM10 data was collected during the years 2005-2007. To beconservative, the 24-hour 1st high PM10 background concentrations were determined based oncalculating the average ofthe maximum concentrations from the period 2005-2007. Provided in

Table B-4 is the 24-hour PM10 ambient background data for 2005-2007.

TABLE B-4. PM10 Background Ambient Air Monitoring Data

Monitor Year 1st High 24-Hour (tg/m 3)

2005 49 Southeast Police Station 2006 45 (Site ID: 245100008) 2007 52

Background 49

Dispersion Model Selection/Options

The most recent version (07026) of the AMS/EPA Regulatory Model (AERMOD) was used tocomplete the dispersion modeling analysis.

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Section C

Modeling Resu1tsINAAQS Analysis

The Severstal Sparrows Point Sintering Plant was modeled to demonstrate compliance with the

24-hour PM10NAAQS due to the proposed SIP revision that would affect only the Severstal

Sparrows Point Sintering Plant. The proposed SIP revision would remove the visible emissions

requirement for this Sintering Plant.

The First high 24-hour modeled PM10concentration was 47.56 jig/rn 3and occurred in 1988.

Adding a 24-hour background concentration of 49 jig/rn 3resulted in a total PM10concentration

of 96.56 jig/rn 3,which is less than the PM10 24-hour NAAQS of 150 jig/rn 3.Provided in Table

C-i are the maximum 24-hour PM10 concentrations for each of the five years modeled.

TABLE C-i. Severstal Sparrows Point Sintering Plant 24-Hour PM10 Modeling Results

Modeled 24-Hour Total

. Receptor Concentration Concentration

Year (jig/rn 3) X (rn) Y (m) (jig/rn 3)

1986 42.36 373532.69 4341232.00 91.361987 39.10 373532.69 4341232.00 88.10

1988 47.56 373532.69 4341232.00 96.561989 45.88 373532.69 4341232.00 94.88

1990 45.42 373532.69 4341232.00 94.42

Notes:

Total Concentration = Modeled 24-Hour Concentration + Background (49 jig/rn 3).24-hr PM10 NAAQS is 150 jig/rn 3.Bold value represents maximum total concentration.

Section D

Conclusion/Analysis Findings

Based on the PM10 dispersion modeling analysis, it was successfully demonstrated that airquality would not be adversely affected by the proposed SIP revision that would affect only the

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