Fig. 1.

The 95% confidence intervals for pyrene concentration based on single-observation sampling events at the Portland Harbor Superfund during fall 2009 to fall 2010. Confidence interval half-widths were calculated as $1.96\ast \sqrt{S_{\mathit{Between}(\mathit{pooled})}^2}$, where $S_{\mathit{Between}(\mathit{pooled})}^2$ for pyrene is based on the pilot study. The confidence interval for log₁₀(x) was calculated using Equation 3 and backtransformed to the original scale using Equation 4. When comparing across two confidence intervals, statistically significant differences between the two groups cannot be concluded if the mean of one interval is within the confidence interval of the other.