The Court of Appeal has upheld an environmental impact report dealing with mining in a dry riverbed in Santa Barbara County.

Troesh Materials, Inc. submitted an application to the County of Santa Barbara ("County") to operate a new mine within the dry bed of the Cayuma River. The mine would be positioned away from the active streambed and roughly 1,500 feet upstream from an existing, active mine. Potential excavation could proceed to a maximum depth of 90 feet, with an average production of 500,000 cubic yards per year.

Save Cayuma Valley, the petitioner, filed a CEQA petition for writ of mandate, which was denied in the trial court. The ensuing appeal involved two topical areas: hydrological and water resource (supply/quality) impacts. As to the first area, the appellate court upheld the County's use of a threshold of significance specific to this proposed project. The County was not compelled to use CEQA's Appendix G thresholds, nor was it obligated to explain why it elected to not use Appendix G thresholds, nor was it obligated to formally adopt the alternative threshold.

Addressing appellant's challenge to the impact conclusions, the appellate court applied the substantial evidence test and concluded that ample evidence (based in part on the evidence and experience acquired from the existing mine located 1500 feet away), existed that there would be insignificant impacts resulting from headcutting or scouring. Appellants also criticized the EIR's suggestion of no impacts followed by then the addition of a proposed mitigation measure, arguing internal inconsistency. The EIR acknowledged that there was some uncertainty in the impact analysis, thus, the appellate court found no inconsistency in the use of backstopping mitigation, but simply a conservative CEQA assessment.

The appellate court then assessed the challenge to one of the mitigation measures. The dispute centered on a mitigation measure responsive to potential hydrology impacts. Despite the EIR's analysis that the impacts would be not be significant, the EIR also recognized the potential for uncertainty, and on that basis, included a mitigation measure, and with that measure, concluded that there would be a less than significant impact. This measure required semi-annual surveys up and downstream be submitted to the State's Office of Mine Reclamation ("OMR"), the County's Planning and Development Department, and the County's Flood Control District as part of OMR's SMARA compliance review. 

The purpose of this review would be to "confer with the County agencies to modify the mining pit layout, width and/or depth to avoid these impacts" should those be detected as part of the review. Although this requirement lacked the detail typically sought in performance based mitigation, the appellate court concluded that as this mitigation requirement was part of the EIR's discussion of hydrologic impacts, the court could rely upon that analysis to establish a context for understanding the mitigation requirement. In other words, the discussion within the EIR provided the missing framework and context to shore up the mitigation requirement. Accordingly, the appellate court rejected appellant's arguments that mitigation lacked the required performance standards to avoid a challenge of deferred mitigation.

The final matters of concern involved water supply and water quality. Appellant claimed that it was error for the lead agency to use the same threshold of significance for both direct and cumulative water supply impact, further arguing that the cumulative effects had been ignored.  The appellate court disagreed, concluding that the standard that was used satisfied the required cumulative analysis, and despite the failure to look at non-cumulative effects, the error was rectified by the more rigorous cumulative impact analysis. 

The appellate court did agree with the appellant that insufficient evidence supported the conclusion of no impact to groundwater, given that the EIR contained potentially conflicting data as to groundwater levels. The County had required compliance with a mitigation measure designed to protect groundwater contamination by requiring a six foot separation between depth of excavation and groundwater, the effectiveness of this strategy which was uncontested. However, in this particular situation, the appellant could not show that the EIR's unsubstantiated conclusion regarding no impact resulted in prejudicial error. Accordingly, the petition for writ of mandate was properly denied.  

[CASE: Name and LEXIS cite with DJDAR cite number]

Save Cayuma Valley v. County of Santa Barbara (2013) ___ Cal. App. 4th ___.