City of Sunnyvale Waste Characterization Report

City of Sunnyvale Waste Characterization Report
Step 2: Note which material classes and materials are present. The visual estimator walks
entirely around the load and indicates on the visual sample form which materials and material
classes are present in the load. The ten material classes are Paper, Glass, Metal, Electronics,
Plastic, Other Organics, Construction and Demolition, Household Hazardous Waste, Special
Waste and Mixed Residue. An example of a material in the Paper material class is newspaper.
Step 3: Estimate composition by volume for each material class. Beginning with the largest
material class present by volume, the visual estimator then estimates the volumetric percentage
of this material class and records it on the form. This process is repeated for the next most
common material class, and so forth, until the volume percentage of every material class has
been estimated. The estimator then calculates the total for this step, ensuring that it totals 100
percent.
Step 4: Estimate composition by volume for each material within each material class. The
visual estimator considers each material class separately and estimates the percentage of that
material class that is made up of each material. For example, the Metal material class includes
the following materials:
— Aluminum Cans
— Tin/Steel Cans
— Other Nonferrous
— Ferrous Metals
The sum of the percentages for all of the materials in each material class must equal 100
percent. This process will be repeated for the other material classes.
Step 5: Check and reconcile percentage data. The visual estimator then makes sure the
percentage estimates for the material classes add up to 100 percent. Also, the percentage
estimates for the materials within each class must total 100 percent.
_ 70 November 2010