Please join us at the 2011 Air & Waste Management Associations Conference & Exposition, June 21-24, in Orlando where we will present:
Statistical Estimates of Long-Term Mercury Emission Limits for Coal-fired Power Plants, J. O. Allen, M. B. Looney, and C. A. Tyree.

Abstract
Reference mercury emissions measurements are based on short-term stack test results, while regulatory compliance standards are usually based on long-term average emissions. A number of statistical methods have been used to develop long-term compliance standards based on short-term stack tests; however, if emissions data do not fit the assumed parametric distribution, the calculated compliance standards may not be achievable by the best performing units. We have compiled over 200 plant-months of operational and emissions data from ten plants which control mercury using co-benefit or activated carbon injection technologies. Monthly and annual averaged emission rates were calculated using block and rolling averages. A large number of stack test results were estimated from continuous mercury emissions data for periods when operating conditions were like those used during stack tests. Statistical methods were used to estimate upper emission limits from these short-term measurements. The statistical methods were based on normal and log-normal distributions. These statistical methods were then evaluated by comparing the calculated upper emission limits with the actual 99th percentile long-term emissions for the same plant and control technology.