Cal. Health & Safety Code § 25244.20

(a) On or before September 1, 1991, and every four years thereafter, each generator shall prepare a hazardous waste management performance report documenting hazardous waste management approaches implemented by the generator.
(b) Except as provided in subdivision (d), the hazardous waste management performance report required by subdivision (a) shall be prepared for each site in accordance with the format adopted pursuant to subdivision (a) of Section 25244.16 and shall include all of the following:
1. (1) The name and location of the site.
2. (2) The SIC Code for the site.
3. (3) All of the following information for each waste stream identified pursuant to paragraph (3) of subdivision (b) of Section 25244.19:
  1. (A) An estimate of the quantity of hazardous waste generated and the quantity of hazardous waste managed, both onsite and offsite, during the current reporting year and the baseline year, as specified in subdivision (c).
  2. (B) An abstract for each source reduction, recycling, or treatment technology implemented from the baseline year through the current reporting year, if the reporting year is different from the baseline year.
  3. (C) A description of factors during the current reporting year that have affected hazardous waste generation and onsite and offsite hazardous waste management since the baseline year, including, but not limited to, any of the following:
    1. (i) Changes in business activity.
    2. (ii) Changes in waste classification.
    3. (iii) Natural phenomena.
    4. (iv) Other factors that have affected either the quantity of hazardous waste generated or onsite and offsite hazardous waste management requirements.
4. (4) The certification of the report pursuant to subdivision (e).
(c) For purposes of subdivision (b), the following definitions apply:
1. (1) The current reporting year is the calendar year immediately preceding the year in which the report is to be prepared.
2. (2) The baseline year is either of the following, whichever is applicable:
  1. (A) For the initial report, the baseline year is the calendar year selected by the generator for which substantial hazardous waste generation, or onsite or offsite management, data is available prior to 1991.
  2. (B) For all subsequent reports, the baseline year is the current reporting year of the immediately preceding report.
(d) If a generator owns or operates multiple sites with similar processes, operations, and waste streams, the generator may prepare a single multisite report addressing all of these sites.
(e) Every report completed pursuant to this section shall be submitted by the generator for review and certification by an engineer who is registered as a professional engineer pursuant to Section 6762 of the Business and Professions Code and who has demonstrated expertise in hazardous waste management, by an individual who is responsible for the processes and operations of the site, or by an environmental assessor who has demonstrated expertise in hazardous waste management. The engineer, individual, or environmental assessor shall certify the report only if the report identifies factors that affect the generation and onsite and offsite management of hazardous wastes and summarizes the effect of those factors on the generation and onsite and offsite management of hazardous wastes.