Why it matters: This is an otherwise run-of-the-mill CEQA case where the main problem in the EIR was the failure to incorporate a threshold of significance and to identify “true” mitigation measures for one impact area.

Facts: The project in the case was essentially highway construction to adjust the alignment of an approximately one-mile stretch of US 101 that passes through Richardson Grove State Park. This stretch of highway is north of San Francisco in an area where US 101 becomes a narrow two-lane highway as it curves through redwood groves. The primary environmental impacts resulting from the project were tree removal and the potential damage to the structural root zones of other trees caused by excavation, placement of fill and other impervious material over roots, etc. The Court found that the EIR failed to properly evaluate the significance of impacts on the root systems of old-growth redwood trees adjacent to the roadway.

Decision: A key issue at the trial court was the enforceability of the mitigation, which the EIR described but which was not part of the mitigation monitoring plan. The trial court found that the mitigation for tree roots would be implemented because Caltrans had an “Environmental Commitments Record” for the project (a tool to track the project specific environmental commitments for a given project) and because Caltrans provided assurances in responses to comments that it would incorporate the mitigation into contract plans and specifications.

However, this was not enough for the Court of Appeal. The Court found that the EIR failed to identify any standard of significance for tree roots despite the fact that there are numerous accepted standards that could have been used. Instead, the EIR’s project description merely introduced mitigation measures as part of the project description and concluded that those mitigation measures reduced impacts to a level less than significant. The Court found that “[b]y compressing the analysis of impacts and mitigation measures into a single issue, the EIR disregards the requirements of CEQA.” Since there was no threshold identified, it was impossible for the Court to determine whether the mitigation measures truly reduced impacts to a level less than significant, whether they were even required, or whether other mitigation measures would be more effective.

Practice Pointers:

  • Always have a significance threshold for anything that is identified as a potentially significant impact.
  • If your EIR is going to have mitigation measures, always identify a threshold of significance first and then impose mitigation measures to reduce impacts to a level less than significant. As opposed to project design features, which are part of the project description, mitigation measures should be geared at reducing impacts identified through a significance threshold.