1. (a) A threshold of significance is an identifiable quantitative, qualitative or performance level of a particular environmental effect, noncompliance with which means the effect will normally be determined to be significant by the agency and compliance with which means the effect normally will be determined to be less than significant.
2. (b) Each public agency is encouraged to develop and publish thresholds of significance that the agency uses in the determination of the significance of environmental effects. Thresholds of significance to be adopted for general use as part of the lead agency's environmental review process must be adopted by ordinance, resolution, rule, or regulation, and developed through a public review process and be supported by substantial evidence. Lead agencies may also use thresholds on a case-by-case basis as provided in Section 15064(b)(2).
3. (c) When adopting or using thresholds of significance, a lead agency may consider thresholds of significance previously adopted or recommended by other public agencies or recommended by experts, provided the decision of the lead agency to adopt such thresholds is supported by substantial evidence.

4. (d) Using environmental standards as thresholds of significance promotes consistency in significance determinations and integrates environmental review with other environmental program planning and regulation. Any public agency may adopt or use an environmental standard as a threshold of significance. In adopting or using an environmental standard as a threshold of significance, a public agency shall explain how the particular requirements of that environmental standard reduce project impacts, including cumulative impacts, to a level that is less than significant, and why the environmental standard is relevant to the analysis of the project under consideration. For the purposes of this subdivision, an “environmental standard” is a rule of general application that is adopted by a public agency through a public review process and that is all of the following:

   1. (1) a quantitative, qualitative or performance requirement found in an ordinance, resolution, rule, regulation, order, plan or other environmental requirement;
   2. (2) adopted for the purpose of environmental protection;
   3. (3) addresses the environmental effect caused by the project; and,
   4. (4) applies to the project under review.

Note: Authority cited: Section 21083, Public Resources Code. Reference: Sections 21000, 21082 and 21083, Public Resources Code; Communities for a Better Environment v. California Resources Agency (2002) 103 Cal.App.4th 98; Protect the Historic Amador Waterways v. Amador Water Agency (2004) 116 Cal. App. 4th 1099.

History

1. New section filed 10-26-98; operative 10-26-98 pursuant to Public Resources Code section 21087 (Register 98, No. 44).

2. Change without regulatory effect amending Note filed 10-6-2005 pursuant to section 100, title 1, California Code of Regulations (Register 2005, No. 40).

3. New subsection (c) and amendment of Note filed 2-16-2010; operative 3-18-2010 (Register 2010, No. 8).

4. Amendment of section and Note filed 12-28-2018; operative 12-28-2018 pursuant to Government Code section 11343.4(b)(3) (Register 2018, No. 52).