Base Year/Reporting Year Policy Home Page/

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. 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.

At its January 25–26, 2000 meeting, the California Department of Resources Recycling and Recovery (CalRecycle) reconsidered its previously approved methods to correct base year inaccuracies. On March 26, 1997, CalRecycle had approved a variety of methods to make these corrections.

CalRecycle decided to reconsider the use of these methods because as time goes on, it is not only increasingly difficult for jurisdictions to make well-documented historic correction estimates for old generation data, but it is also more problematic for CalRecycle staff to determine the validity of the claims. CalRecycle did not make any changes to the actual calculation methods that had been previously approved, but it did set some time limitations on when they could be used. A downloadable version of the resolution (No. 1999-38) setting forth these limitations is summarized below.

Summary of CalRecycle Limitations on Correcting or Establishing New Base Years

In the future, CalRecycle will not allow corrections to any CalRecycle-approved base-year disposal or diversion tonnage amount that is more than three calendar years old. For example, if a jurisdiction establishes a new 2000 base year, CalRecycle will not consider a request for a correction to that base year after calendar year 2003.  Exceptions will be made for jurisdictions that:

  • Submitted a formal request with all supporting documentation for a base-year correction before March 31, 2000;
  • Submitted a request in conjunction with their 1997 or 1998 annual report by January 25, 2000; or
  • Are currently on CalRecycle-issued compliance orders for data problems.

CalRecycle has developed a Diversion Study Guide to help jurisdictions with information and tools to calculate new base years. CalRecycle’s local assistance staff has developed a series of CalRecycle Approved Templates to assist jurisdictions when claiming changes to CalRecycle-approved base-year disposal or diversion amounts, when claiming changes to reporting-year disposal amounts, when using alternate adjustment factors to calculate an annual diversion rate, or when establishing a new base year.

If you have questions about the above limitations, please contact your local assistance staff representative at (916) 341-6199.

For more information contact: Local Assistance & Market Development,