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Data Analysis of City of Roseville Recyclable Materials <br />The results of each comparison are shown in several tables, along with the Project <br />Team's interpretation of the data. <br />The mean, and upper and lower 90% confidence intervals are provided along with a <br />column titled "Statistically Significant Difference ". If there is a check mark in this <br />column, it indicates that the ranges of the lower and upper confidence intervals <br />between the two collection methods are statistically different. That is, there was no <br />overlap in the percentages and therefore the results between the two methods reflect a <br />statistically significant difference. <br />Comparison of the Monday Collection Routes <br />Two Monday collection routes were chosen by the City to be the pilot areas for the <br />single stream collection method. The main difference between the two areas was the <br />age of the housing stock. The first pilot route included older homes, typically with <br />detached, single car garages and higher density than the second pilot route. The <br />second route included newer homes, typically with attached, two stall garages, and <br />lower density than the first pilot route. <br />For the comparative analysis shown below, the composition results of the two Monday <br />routes during the pilot were combined into one data set for September and one data set <br />for October. <br />Table 4 <br />Comparison of Monday Routes - July and September <br />Light samples were sorted trom two Monday routes. <br />% Four samples were sorted from two Monday routes. <br />J The totals may not equal the sum of the material categories due to rounding. <br />B1605 B -5 <br />Monday Dual Stream Routes' <br />Monday Single Stream Routesz <br />July <br />September <br />Statistically <br />90% Confidence <br />90% Confidence <br />Significant <br />Interval <br />Interval <br />Difference <br />Material <br />Mean <br />Lower <br />Upper <br />Mean <br />Lower <br />Upper <br />Category <br />Paper <br />57.9% <br />54.5% <br />61.3% <br />78.7% <br />75.0% <br />82.4% <br />✓ <br />Metals <br />7.9% <br />7.3% <br />8.5% <br />2.8% <br />2.0% <br />3.6% <br />✓ <br />Glass <br />19.7% <br />16.4% <br />23.0% <br />5.3% <br />4.4% <br />6.2% <br />✓ <br />Plastic <br />10.7% <br />9.0% <br />12.4% <br />6.0% <br />4.8% <br />7.2% <br />✓ <br />Contaminants <br />3.9% <br />2.1% <br />5.7% <br />7.1% <br />5.8% <br />8.4% <br />✓ <br />Total3 <br />100% <br />n/a <br />n/a <br />100% <br />n/a <br />n/a <br />Light samples were sorted trom two Monday routes. <br />% Four samples were sorted from two Monday routes. <br />J The totals may not equal the sum of the material categories due to rounding. <br />B1605 B -5 <br />