Appendix A - Washington State Department of Ecology

October 21, 2008
Final December 2010
The emission rates modeled were derived from operating records of the rotary kiln and reflect
the highest 24-hour emission rate within the three years that were modeled. The emission
reduction percentages (see table above) were applied to this maximum 24-hour emission rate and
those rates were then used for modeling the visibility impairment/improvement that could be
achieved using the proposed controls. The maximum day SO2 emissions during the three years
of modeling were not used as that day was reported to be in an abnormal, upset operating
condition. In reviewing the emission information, it is also unusually high compared to all other
monitored days in the 3-year period. The modeled emission rates are shown in Table 3-1.
Ecology modelers have reviewed the modeling performed by Lafarge and have found that the
modeling complies with the Modeling Protocol and produces a reasonable result.
The modeled emission reductions result in substantial reduction in the visibility impairment
caused by Lafarge in all Class I areas modeled and in the Columbia River Gorge NSA. At the
three most heavily impacted Class I areas, Olympic National Park, Mt. Rainier National Park,
and the Alpine Lakes Wilderness, Lafarge’s proposed BART controls would provide 0.8 to 1 dv
reduction in visibility impairment in each of these areas.
L - 239