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.
Without the adjustment method, population increases and economic booms would result in jurisdictions with lower diversion rate estimates. The adjustment method uses base-year generation tons and three factors to estimate report-year generation tons: percentage change in population, employment, and taxable sales adjusted for inflation.
- “Base-year generation” means the amount of waste generated by a jurisdiction during the calendar year used for a jurisdiction’s solid waste generation study. The waste generated by a jurisdiction includes all solid waste disposed or diverted. Base-year generation is the basis for subsequent year Board estimates of jurisdiction generation tons and diversion rates.
- “Default values” means standard measurements of population and economic growth for cities, counties, and regions calculated by state and federal agencies and incorporated by the Board into its diversion rate calculator.
- “Residential percentage” means that portion of a jurisdiction waste stream created by single- and multi-family residences.
Using the Adjustment Method to Estimate a Diversion Rate
- Jurisdictions must estimate their base-year residential waste generation percentage because population and economic growth affect residential and non-residential waste generation differently.
- Most jurisdictions use county-level or jurisdiction-specific default factor values supplied by the Board. Others may use factor values from independent third parties with case-by-case Board approval. The same source must be used for both the base year factor and the report year factor.
- The Board’s online diversion rate calculator incorporates base-year generation tons, base-year residential generation percentage, adjustment factors, and report-year disposal tons into the diversion rate estimate. This diversion rate calculator is part of the electronic annual report that a jurisdiction my use to file its annual report to the Board.
- The adjustment method does not correct for inaccurate base-year generation or report-year disposal amounts. Proposed corrections should be discussed in a jurisdiction’s annual report to the Board.
- If a jurisdiction thinks changes in its waste stream were not accurately reflected by changes in population, employment or inflation-adjusted taxable sales, it may discuss its reasons in its annual report to CalRecycle. A jurisdiction may also contact the Board’s local assistance staff or the Local Assistance-Los Angeles Section for further assistance.
Legislation, Statutes, and Regulations
Chapter 1292, Statutes of 1992 (Sher, AB 2494), amended by Chapter 978, Statutes of 1996 (Bustamante, AB 1647)
Statute: Public Resources Code (PRC) Section
PRC 41780.1, Waste Diversion Planning Requirements
Title 14, California Code of Regulations (14 CCR), Chapter 9, Article 9.1, Adjustment Method for Calculating Changes in Waste Generation Tonnage
- Adjustment Method Factors: Detailed descriptions of the population and economic factors used in the Board-approved adjustment method and the adjustment method formula.
- Default Adjustment Factors: Search this CalRecycle on-line database to find default adjustment factors for all California jurisdictions.