This page informs interested parties about the the overall statewide diversion rate calculation for 2004. This information was first released at the May 11, 2005, Board meeting by Mark Leary, Executive Director of the California Integrated Waste Management Board.

2004 Estimated Diversion Rate—48 Percent


California's statewide diversion rate estimate for 2004 is 48 percent, 1 percent higher than the 2003 estimate. It is much higher than prior benchmark years: 17 percent for 1990, 28 percent for 1995, and 42 percent for 2000. Since waste is generated by a wide variety of activities, understanding diversion rate change is challenging. California's 2004 waste stream grew in every way: 3.0 percent more tons were generated, 2.5 percent more tons were disposed, and 3.5 percent more tons were diverted.


Each year the Board's Diversion, Planning and Local Assistance Division (DPLA) reports on statewide progress toward the diversion goals of the Integrated Waste Management Act of 1989. Prior to 1997 the statewide diversion rate estimate was typically available in late spring due to the Disposal Reporting System (DRS) schedule and availability of information provided by the State Board of Equalization. Starting in 1997 staff made efforts to ensure earlier, more uniform diversion rate estimates. The statewide diversion rate estimates are now based on the Federal Fiscal Year (FFY) for example, October 1, 2003 through September 30, 2004. This change provides an earlier diversion rate estimate.


Generation Up 3.0 Percent

An estimated 77.9 million tons were generated in 2004, nearly 2.3 million tons or 3.0 percent more than in 2003. California uses population, employment, and inflation-adjusted taxable sales growth to estimate solid waste generation. For 2004, population was up 1.6 percent and employment was up 1.5 percent. For 2004, taxable sales were up 6.8 percent. A notable driver of California’s 2004 economy, and perhaps its waste generation growth, was construction. Construction activity statewide remained very active and is expected to remain active for the next several years.

Disposal Up 2.5 Percent

For 2004, disposal amounted to 40.9 million tons, nearly 1.0 million tons or 2.5 percent more than in 2003. While this is an increase in disposal tons, it is less than half the 2.3 million disposal ton increase that occurred between 2002 and 2003.

California’s 2004 construction activity growth, and the challenges associated with diverting construction and demolition (C&D) debris, may have significantly contributed to this increase in disposal. Staff analysis shows that there is a strong relationship between disposal tonnage and construction activity, as measured by construction employment and residential construction authorized by permits. The California construction industry employment sector showed the largest percent change in employment during 2004. While overall industry employment increased slightly, construction employment increased over 7 percent (Figure 1). Since 1999, construction employment has increased 23 percent, while overall employment has increased by only 3 percent (Figure 2). Residential permits, another major construction indicator, increased by 8.4 percent in 2004. Since 1999, residential permits have increased over 51 percent (Figure 3).

In addition, the disposal impact of a 1.6 percent population increase for 2004 should not be overlooked.

Diversion Up 3.5 Percent

An estimated 37.0 million tons were diverted in 2004, nearly 1.3 million tons or 3.5 percent more than in 2003. In response to the increase in construction activity, the Board and jurisdictions have significantly increased efforts to divert construction materials. New construction material diversion programs have been implemented and many more are in the planning stage. More green waste and single-stream recyclables diversion programs may also have contributed to this increase in diversion.

Further Research

Staff is working with faculty from the Economics Department at California State University, Sacramento (CSUS) and stakeholders to determine if, given changes in what drives the economy, the Board’s Adjustment Method (AM) accurately estimates changes in waste generation over time, and if the AM can be improved. Staff expects to take recommendations to the Board later in 2005.

Calculation Methodology

The purpose of AB 939 is to conserve resources and extend landfill capacity, not penalize jurisdictions for increases in population or economic growth. Thus, when population and the economy grow, jurisdictions will not automatically fail to meet the diversion goals. The impacts of demographic and economic changes on the waste stream must be considered when calculating diversion rates. By incorporating these demographic factors, the AM allows comparisons between years regardless of the changes in population and economics.

The first step in performing the calculation is to determine the 2004 statewide waste generation tonnage. Generation is the total amount of waste disposed and diverted. To arrive at this number, we estimate the statewide base year (2000) generation tonnage, taking into account new jurisdiction base years. Next, we estimate 2004 generation using the AM, which uses change in population and the economy since the base year. 2004 estimated statewide generation is approximately 77.9 million tons.

The next step is to determine 2004 statewide disposal. Disposal is the total amount of waste that is landfilled, exported out of state, and transformed. However, since statewide transformation is less than 10 percent of total estimated generation, transformation was excluded from total disposal and, thus, counted as diversion. The Disposal Reporting System (DRS) tracks the amount of waste disposed by each jurisdiction in the state. However, because DRS data has not been received from some counties for the 3rd quarter of 2004, the Board of Equalization’s (BOE) Integrated Waste Management Fee data is used to fill the gaps. After combining the disposal tonnage from these data sources and subtracting disaster waste, 2004 total disposal is 40.9 million tons. Dividing this number by statewide generation, we arrive at a disposal rate of 52 percent. To determine the 2004 diversion rate, we subtract disposal (52 percent) from generation (100 percent) to get 48 percent. Approximately 37.0 million tons were diverted from landfills in 2004. For details, please see Table 1.

Return to current year diversion rates memo to view previous years' statewide diversion rates.

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