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Appendix B Table 19 Comparison of Dual Stream Routes Before vs. During Pilot Seven samples were sorted trom the July dual stream routes. 2Thirteen samples were sorted from the dual stream routes. 3The totals may not equal the sum of the material categories due to rounding. The upper and lower confidence intervals of the dual stream routes during the pilot program were not significantly different than the dual stream routes before the pilot was initiated. Thus, the July composition results can be considered representative of dual stream collection for the City of Roseville. Summary The results of the comparative analysis of the pilot routes are summarized below. Comparison of the Monday Collection Routes The upper and lower confidence intervals from both the September and October Monday single stream pilot routes reflect a statistically significant difference when compared to those of the July (pre- pilot) dual stream route. Thus, the materials composition is projected to change when comparing single stream to dual stream collection. When comparing the material compositions by weight for the Monday collection routes, the results include: ■ The quantities of paper collected via the single stream method (September and October) increased compared to the quantities collected via the dual stream method (July); ■ The quantities of metals, glass, and plastic decreased with the single stream collection method; and B-16 B1605 Tues- Friday Dual Stream Routes' Tues- Friday Dual Stream Routes 2 July (Before) September & October (During) Statistically 90% Confidence 90% Confidence Significant Interval Interval Difference Material Mean Lower Upper Mean Lower Upper Category Paper 61.3% 52.7% 69.9% 61.5% 54.7% 68.2% Metals 6.6% 4.3% 8.9% 7.1% 5.6% 8.6% Glass 18.7% 13.1% 24.3% 18.4% 12.3% 24.4% Plastic 9.9% 5.4% 14.4% 9.6% 6.7% 12.5% Contaminants 3.5% 2.4% 4.6% 3.5% 2.6% 4.4% Tota13 100% n/a n/a 100% n/a n/a Seven samples were sorted trom the July dual stream routes. 2Thirteen samples were sorted from the dual stream routes. 3The totals may not equal the sum of the material categories due to rounding. The upper and lower confidence intervals of the dual stream routes during the pilot program were not significantly different than the dual stream routes before the pilot was initiated. Thus, the July composition results can be considered representative of dual stream collection for the City of Roseville. Summary The results of the comparative analysis of the pilot routes are summarized below. Comparison of the Monday Collection Routes The upper and lower confidence intervals from both the September and October Monday single stream pilot routes reflect a statistically significant difference when compared to those of the July (pre- pilot) dual stream route. Thus, the materials composition is projected to change when comparing single stream to dual stream collection. When comparing the material compositions by weight for the Monday collection routes, the results include: ■ The quantities of paper collected via the single stream method (September and October) increased compared to the quantities collected via the dual stream method (July); ■ The quantities of metals, glass, and plastic decreased with the single stream collection method; and B-16 B1605