Ambient TRS and SO2 Concentrations from a Bleached Kraft Mill with Advanced Emission Control, 1998 Environmental Conference Proceedings

The Johnsonburg Mill of Willamette Industries is a 600 ADTBP/day kraft mill located in the heart of small community with residences located immediately adjacent to mill property. A rebuild of the mill was completed in 1994 incorporating state-of-the-art process unit design and emission controls for all significant mill sources of TRS. The TRS gas collection system was designed to be MACT compliant. All gases are burned in an incinerator under normal conditions and are redirected to backup combustion units when incinerator operations are interrupted. Temporary TRS gas ventings during changeovers to the alternative combustors were occasionally the source of community odor problems. An optimized transfer protocol significantly reduced the number of venting occurrences. Due to complaints from neighbors about odors from the mill, the Pennsylvania Department of Environmental Protection instituted a temporary ambient monitoring site for sulfur dioxide and TRS gases at the residence of a nearby complainant. Monitoring was performed to determine compliance with the sulfur dioxide NAAQS and Pennsylvania’s hydrogen sulfide ambient standards. Due to the measurement system design, all TRS compounds were measured and reported as H2 S. Sampling was conducted from May through September, 1997. During this period, the 24-hour average TRS levels exceeded the Pennsylvania limit for H2 S on two days reaching 0.006 ppm and 0.007 ppm. The highest one-hour TRS averages was 0.027 ppm. The highest three-hour and 24-hour averages for SO, were 0.064 ppm and 0.029 ppm, respectively; both well below the applicable ambient standards. Five-minute average SO, concentration were less than 0.6 ppm. Ambient impacts were correlated with wind direction but not specific mill activities except major maintenance during a mill shutdown.