California Department of Resources Recycling and Recovery (CalRecycle)

Diversion Study Guide, Appendix I

Conversion Factor Sources

Note: This page contains historical information from CalRecycle’s statewide goal measurement prior to 2007 that estimated a diversion percentage. For 2007 and subsequent years, CalRecycle compares reported disposal tons to population to calculate per capita disposal expressed in pounds/person/day. This new goal measurement system is described in CalRecycle's Goal Measurement: 2007 and Later web page. web page. With the implementation of this measurement system, CalRecycle will only accept new base year studies commenced prior to June 30, 2008. A jurisdiction may conduct a generation study for internal review purposes; however, CalRecycle will not review it for compliance determination.

The following studies have been identified as potential sources of conversion factors.  The weights provided in the referenced studies may not be representative of every jurisdiction within the state and should be used only if they accurately reflect the weight of items and materials submitted in the jurisdiction’s diversion study.  The new base-year study proposal should include a discussion of the applicability of any conversion factors used and the source for the conversion factors used.

General studies

Business Waste Prevention Quantification Methodologies - Business Users Guide: Washington, D.C. and Los Angeles:  U.S. Environmental Protection Agency, Municipal and Industrial Solid Waste, and University of California at Los Angeles Extension, Recycling and Municipal Solid Waste Management Program, 1996.  Grant Number CX 824548-01-0.  This guide includes weight of paper office products, office furniture, and computers.  Copies of this study are available from the CalRecycle local assistance staff.

Measuring Recycling:  A Guide For State and Local Governments.  Washington, D.C.:  U. S. Environmental Protection Agency, 1997:  Phone 1-800-424-9346; http://www.epa.gov.  Publication number EPA530-R-97-011.  This guide includes weights of items including glass, metals, paper, plastics, textiles, tires, organics, and municipal solid waste. For material types listed in both the U.S. EPA and Cal Recovery/Tellus studies, the more current factors in the U.S. EPA study should be used.

Conversion Factors for Individual Material Types Submitted to California Department of Resources Recycling and Recovery (CalRecycle).  Cal Recovery Inc., Tellus Institute, and ACT…now, December 1991.  Copies of this study are available from the CalRecycle local assistance staff.  This study includes weights of paper, plastics, glass, metals, organics, tires and rubber products, crop residues, textiles, and inerts. For material types listed in both the U.S. EPA and Cal Recovery/Tellus studies, the more current factors in the U.S. EPA study should be used.

FEECO International Handbook, 8th Printing (Section 22-45 to 22-510).  Green Bay, WisconsinFEECO International, Inc.  Phone (920) 468-1000;  FAX (920) 469-5110.  This handbook includes weights of items including construction and demolition materials, plastics, paper, organics, textiles, and metals.

Grasscycling studies

These studies may not be applicable for communities in arid or snowy climates.  Jurisdictions should provide justification for using these conversion factors.  Jurisdictions should conduct a statistically significant survey to determine the number of households participating in grasscycling.  Some households practice both grasscycling and backyard composting.  Surveys should be designed to avoid double counting.

Harivandi, M. A., et al. "Grasscycling in California" California Turfgrass Culture, Vol. 46, Nos. 1 and 2, 1996, Copies of this study are available from the CalRecycle local assistance staff.

Hartin, Janet, and J. Michael Henry. "Reusing Turfgrass Clippings To Improve Turfgrass Health and Performance," University of California Cooperative Extension,   Copies of this study are available from the CalRecycle local assistance staff.

Residential composting studies

These studies may not be applicable for communities in arid or snowy climates.  Jurisdictions should provide justification for using these conversion factors.  Jurisdictions should conduct a statistically significant survey to determine the number of households participating in backyard composting.  Some households practice both grasscycling and backyard composting.  Surveys should be designed to avoid double counting.

"Source Reduction Through Home Composting," Alameda County Waste Management Authority Home Composting Survey.  Summarypublished in Biocycle, April 1992.  This study calculates weight for residential composting activity.

"Home Composting with the Soilsaver: An Empirical Study of Waste Diversion in the Regional Municipality of Hamilton-Wentworth, Ontario."  Summary published in Resource Recycling, December 1991.  This study calculates weight for residential composting activity.

Thrift store and garage sale activity

To calculate diversion tonnage for thrift store and garage sale activities, a jurisdiction should conduct a survey and provide a reasonable estimate with supporting documentation.

Conversion factor tables

Table of Contents

Last updated: September 8, 2009
Local Government Library http://www.calrecycle.ca.gov/LGCentral/Library/
Local Assistance & Market Development: LAMD@calrecycle.ca.gov (916) 341-6199