DATE: February 7, 2011 FILE REF: 4530

FID: 744008100 TO: Joseph Hoch – AM/7 Neal Baudhuin – NOR (Rhinelander)

FROM: John Roth – AM/7

SUBJECT: Air Dispersion Analysis for Wausau Paper Mills – Rhinelander (Oneida County)

A. INTRODUCTION

A dispersion modeling analysis was completed on February 5, 2011 to assess the impact to ambient air of sulfur dioxide (SO 2 ) emissions from Wausau Paper Mills in Rhinelander (Oneida County). This analysis was performed in support of the technical support document for Oneida County SO 2 nonattainment.

B. MODELING ANALYSIS

• Stack parameters used in this analysis were derived from historical dispersion mode ling analyses combined with permit allowable emission rates. Building dimensions were determined using BPIP-PRIME with measurements taken on plot plans provided by Wausau Paper Mills – Rhinelander (WPMR). Please refer to the source parameter table for modeled values.

• The results from the preliminary modeling analysis we re lower than the measured design value from the

Rhinelander monitor. Sin ce no other sources of SO 2 exist in the immediate area, the result from the modeling of WPMR should match the measured design value. Fu rther sensitivity tests with ot her, distant sources, andwith other meteorological data sets also had modeled impacts less than those monitored. Without having instack emission parameter monitoring, it is uncertain what stack conditions led to the high monitor values. Therefore, for this analysis the exit gas temperature and exit gas velocity were adjusted downward until the modeled concentration at the receptor nearest the Rhin elander monitor matched the measured design value.

• Five years (1998-2002) of pr eprocessed meteorological data was used in this analysis. The surface data was collected in Rhinelander (RHI), and the upper air meteorological data originated in Green Bay.

• The AERMIC (AMS/EPA Regulatory Model Improvement Committee) Model (AERMOD) was also used in the analysis. The model used rural di spersion coefficients with the regulatory default options. These allow for calm wind and missing data correction, buoyancy induced dispersion, and building downwash including recirculation cavity effects.

• USEPA guidance specifies that the highest hourly measured SO 2 value be used for regional background. The monitoring data in Wisconsin from 1998-2009 was collected and examined to determine if any sites could serve as regional background for Rhinelander. SO 2 has generally been monitored near industrial facilities and most of the maximum hourly values are very high. Theref ore, in this analysis all nearby sources of SO 2 will be explicitly modeled and a background value from a non-industrial monitoring location will be used. The Forest County Potawatomi Community operates a monitor that is ~45km from any major source of SO 2 , and the maximum hourly value from 2007-2009 (39.2 μ g/m 3 ) will serve as the hourly regional background

concentration. Additional emissions of SO 2 will then be input to the model from Red Arrow Foods in Rhinelander and Packaging Corporation of America in Tomahawk. 

### State of Wisconsin 

## CORRESPONDENCE/MEMORANDUMC. MODEL RESULTS

The overall goal of this analysis is to examine the geographic extent of the high SO 2 concentrations. While there may be some long-distance (great er than 100 km) transport of SO 2 , it is expected that individual facilities are the primary culpable sources. Because of th is, the area that experiences concentra tions above the standard may be much less than the presumed county-wide nonattainment. The resu lts from this dispersion modeling analysis were postprocessed to produce the five-year average of the 99 th percentile of the daily maximum concentration. This data was entered into a geographic information service (GIS) program to produce the images on the following pages. The results shown include the modeled impact plus the es timate of regional background concentration.

Note that the areal extent shown is defined by the maxi mum modeled design value concen tration at each receptor. For any particular hour only a small subset of points is affected, and the locations of the affected points vary throughout the day and throughout the year.

WAUSAU PAPER MILLS - RHINELANDER

Emission Rates & Stack Parameters

Stack

ID LOCATION (UTM83) HEIGHT (M) DIAM (M) VELOCITY (M/S) TEMP (K) SO 2 #/HR

S08 311338, 5056922 35.66 1.68 20.08 439.0 15.23

S09 311349, 5056895 63.09 2.13 5.00 345.0 1050.0

S11 311384, 5056829 60.96 3.35 3.00 400.0 471.5

Red Arrow Foods Rhinelander Sources

S07 307577, 5055183 12.56 1.01 14.40 444.3 3.23

S10 307604, 5055176 15.54 1.07 13.20 366.5 3.23

PCA Tomahawk Sources

S14 285952, 5036176 46.60 1.37 4.64 470.4 140.3

S15 285952, 5036203 60.70 3.23 16.50 468.0 2563.0OneidaForestLincolnVilasLangladeIronPriceTaylorFlorenceRhinelander1-Hour SO2Modeling GridCity/Village/TownsCounty Names0 10 205 MilesPELICANPINE LAKESTELLACRESCENTNEWBOLDMONICORhinelanderENTERPRISEHARRISONCASSIANSUGAR CAMPSCHOEPKEKINGTHREE LAKESWOODBOROLAKE TOMAHAWKRhinelander1-Hour SO2Modeling GridCity/Village/Town Names0361.5 MilesPELICANPINE LAKESTELLACRESCENTNEWBOLDMONICORhinelanderENTERPRISEHARRISONCASSIANSUGAR CAMPSCHOEPKEKINGTHREE LAKESWOODBOROLAKE TOMAHAWKRhinelander1-Hour SO2Receptors> 95% StdCity/Village/Town Names0361.5 MilesRhinelander1-Hour SO2Receptors> 95% Std0120.5 Miles