March 2006 AQC H2S Study Update DAQ Progress Report on Hydrogen Sulfide Study at Paper Mills Presentation Summary - Rule requirements for monitoring study.

March 2006 AQC H2S Study Update

DAQ Progress Report on Hydrogen Sulfide Study at Paper Mills

• Presentation Summary

- Rule requirements for monitoring study

- Conduct and reporting of study

- DAQ review for approval

- Study purpose:

Replace prior uncertain data with quality- assured data from actual monitoring

March 2006 AQC H2S Study Update

Rule Requirements for Emission Study

• April 2005 effective date reducing hydrogen sulfide (H2S) Acceptable Ambient Level (AAL) from 2.1 to 0.12 mg/m3 (1,500 ppb to 83 ppb)

• Included exemption of wastewater treatment systems (WWTS) at paper mills

• Required paper industry to conduct WWTS study estimating H2S & total reduced sulfur (TRS) compounds emissions

• Study report to DAQ in November 2005• DAQ report to EMC in January 2006

March 2006 AQC H2S Study Update

Rule Requirements For Dispersion Modeling

• Use estimates from study in dispersion modeling• If dispersion modeling shows predicted H2S level

below AAL, no further action required.• Submit favorable modeling data to DAQ by July

1, 2006, with DAQ reporting results to EMC by September 1, 2006.

• If modeling shows H2S AAL exceeded, industry submit ambient air monitoring plan to assess actual H2S levels typical of mill operations by September 30, 2006 for DAQ approval.

March 2006 AQC H2S Study Update

Scope of Phase I Study

• Minimum scope: Estimate air emissions at typical paper mills for H2S and TRS

• Implemented scope:- Measure air emissions at 3 paper mills

for H2S, TRS, and methane - Measure water composition and flow- Combine air and water data for mass balance- Develop model to predict air emissions- Synthesize emissions for one mill

March 2006 AQC H2S Study Update

Air Emission Monitoring

• Identified method from similar 1989 mill study• Method consists of measuring downwind plume:

- At 10+ horizontal locations- At 4 vertical elevations- Using mobile sampling cart and tethered balloon- 6 and 30 ft high weather stations • Considered sophisticated and advanced approach

March 2006 AQC H2S Study Update

Ambient Air Sampling Equipment

March 2006 AQC H2S Study Update

March 2006 AQC H2S Study Update

Phase I Study Schedule

1st Site Weyerhaeuser-Plymouth April 2005

2nd Site Weyerhaeuser-New Bern May 2005

3rd Site International Paper -Roanoke Rapids

August 2005

Report Preparation Sept - October 2005

Report submittal November 2005

March 2006 AQC H2S Study Update

DAQ Involvement in Study

• Started in May 2004

• Team of DAQ chemists, engineers, and dispersion modelers

• With 2 NCSU professors

• Hired expert analyst with experience in same method with same sulfur compounds

• Collaborated with US EPA chemists and engineers

March 2006 AQC H2S Study Update

DAQ Review for Approval

• Sampling and math procedures approved

• However, given key QA criterion not routinely met, found most analytical data unacceptable

• EPA found analytical data “questionable, …

hopes more suitable study conducted in future”

• Feasible Phase II study data collected and modeled in time for July 2006 milestone

March 2006 AQC H2S Study Update

Unacceptable Analytical QA Results

Weyerhaeuser Plymouth Check Standard Analysis Results(acceptance criteria from Weyerhaeuser Plymouth Report

Appendix E, Section 5.3)

0

50

100

150

200

0 50 100 150 200 250 300

Elapsed time, hours, beginning 04/14/05

Perc

en

t S

am

ple

Reco

very

low check standard meeting NCASI +/- 30%

Hi check standard meeting NCASI +/- 30%

low check standard not meeting NCASI +/- 30%

Hi check standard not meeting NCASI +/- 30%

NCASI Requirement +/- 30 % of actual sample concentration[70 to 130 % sample recovery]

March 2006 AQC H2S Study Update

Phase II Study Plan

• Industry submitted Phase II Plan in February 2006• DAQ approved plan with one minor change• Re-measure emissions at Plymouth & Roanoke Rapids

- Synthesize emissions for other 2 mills• Key analytical QA data good in Pre-Phase II work • Perform dispersion modeling for all 4 mills to predict

hydrogen sulfide levels at property lines• Plan to submit emission study and dispersion modeling

results by July 2006

March 2006 AQC H2S Study Update

Acceptable Analytical ResultsPre-Phase 2 QA Results

60%

80%

100%

120%

140%

2/16/06 2/17/06 2/18/06 2/19/06 2/20/06 2/21/06 2/22/06 2/23/06 2/24/06 2/25/06 2/26/06 2/27/06 2/28/06

Date

Av

era

ge

Re

co

very

, %

Hydrogen sulf ide

Methyl mercaptan

Dimethly sulf ide

Dimethly disulf ide

QA Guideline 70 - 130 % Recovery

March 2006 AQC H2S Study Update

Phase II Study Schedule

1st Site Weyerhaeuser- Plymouth March 2006

2nd Site International Paper -Roanoke Rapids

April 2006

Emission Estimates and Dispersion Modeling Report Submittal

July 2006