The California Environmental Quality Act requires an Environmental Impact Report (EIR). There is a short description and a long description. The requirements for the EIR for the Draft Proposed Encinitas Housing Element can be found here.
An EIR covers 18 factors:
Geology and Soils
Hazards and Hazardous Materials
Hydrology and Water Quality
Land Use and Planning
Population and Housing
Transportation and traffic
Utilities and Service Systems
Mandatory Findings of Significance
An EIR of necessity will be a product of human judgment, and the lack of clear thresholds can lead to litigation. Problems can also occur on the grounds that EIRs are too brief or overlooked possible impacts, as there are no explicit guidelines.
Regardless of the problems, an EIR is required for civic projects such as the Encinitas Housing Element.