Court Of Appeal Finds County Approval Of EIR For Sand And Gravel Mining Project Does Not Violate CEQA

An organization challenged a county’s approval of a final revised environmental impact report for a project that would allow sand and gravel mining in the bed of the Cuyama River.  The court of appeal affirmed the trial court’s decision that denied the organization’s challenge to the county’s approval of the environmental impact report.  (Save Cuyama Valley v. County of Santa Barbara (— Cal.Rptr.3d —-, Cal.App. 2 Dist., February 8, 2013).


Troesh Materials, Inc., (“Troesh”) applied to the Planning and Development Department of the County of Santa Barbara (“County”) for a conditional use permit.  Troesh wanted to excavate and process sand and gravel for a project called the “Diamond Rock mine.”  Diamond Rock mine is to be located in the bed of the Cuyama River, which is often dry, at a stretch where the riverbed is 2,500 feet wide.  The project would excavate approximately 900 feet from the Cuyama River’s usual flow and the excavated materials would be processed at a facility located above the riverbed.  The mine would be located approximately 1,500 feet upstream from another mine that excavates sand and gravel, known as the GPS mine that has been in operation since 1969 and excavates an average of 160,000 tons of material per year. 

The plan for the Diamond Rock mine is to excavate over time “a series of trenches with a new trench being started once the prior trench reached the maximum depth of 90 feet.”  An average of 500,000 tons would be excavated each year and the project would cover 84 acres by the end of the 30-year permit.  County commissioned the preparation of an environmental impact report, received comments, revised the report, and then released a Final Revised Environmental Impact Report (“Report”).  County’s Board of Supervisors adopted and certified the Report. 

The Cuyama River carries water and sediment as it flows including a net surplus of 229,000 tons of sediment every year in the area where GPS mine currently operates and Diamond Rock mine seeks to operate.  If GPS mine and Diamond Rock mine “were to excavate sand and gravel solely from the river’s flows, their combined annual extraction of 1 million tons per year (500,000 for the Diamond Rock mine and a new higher limit of 500,000 for the GPS mine) would result in an annual sediment deficit of 771,000 tons in that area.” 

The project mine would not be in Cuyama River’s path and Troesh would surround the mine with “low flood control berms” that would direct the river’s flows around the excavations.  However, during substantial rains, the river would be expected to overrun the berms and flow into the excavation pits.  The Report recognizes Diamond Rock mine “could affect river hydraulics” and identifies three possible hydraulic impacts.  The identified impacts are (1) “downstream channel degradation,” (2) “headcutting,” and (3) “bank erosion.”  The Report concludes that the impacts are not likely to occur.  It further “concludes the ‘magnitude’ of the three possible impacts previously identified are ‘expected to be minor’ and would likely have no secondary impacts (to infrastructure, adjacent development or habitats)” and that the “mine’s    hydrological impacts ‘appear to be less than significant.’”  The Report, however, “acknowledges ‘the inherent uncertainty of simulation models and the potential to underestimate [hydrological] effects,’” and “deems these impacts to be ‘potentially significant but mitigatable.’” 

The Report proposes a mitigation measure that Troesh must implement in order to receive a conditional use permit to operate the mine.  Pursuant to this mitigation measure, Troesh “must conduct a semi-annual survey of river bottom elevations in three locations,” and submit the data to State’s Office of Mine Reclamation and County agencies as part of the annual Surface Mining and Reclamation Act compliance review.  If adverse hydraulic conditions are evident, or if they appear to be developing in a manner that could result in off-site impacts, Troesh must confer with “County agencies to modify the mining pit layout, width and/or depth to avoid these impacts.” 

The Report analyzed the impact of the Diamond Rock mine on the usage and quality of local water supply.  The Report calculated the mine’s consumption of water and classified the impact as not significant. The Report also noted that the mine could “affect the already ‘relatively poor’ quality of the water in the Cuyama River basin if excavation exposes groundwater.”  The Report

classified the Diamond Rock “mine’s impact on water quality as ‘adverse, but not significant’” because of “(1) the ‘very low’ frequency with which groundwater would be exposed; (2) the ‘very short’ duration for which it would be exposed before percolating back into the ground; and (3) the ‘very small’ surface area of the exposed groundwater ‘compared to the groundwater stored in the basin.’”  However, the County imposed Condition 64 on the conditional use permit. Condition 64 “prohibits excavation ‘to the level of groundwater’; requires excavation to remain ‘at least an average of six feet above water level’; and obligates Troesh to backfill any pit to a depth of six feet should any groundwater be exposed.”

Save Cuyama Valley (“SCV”) petitioned the trial court for a writ of mandate compelling County to correct deficiencies in the Report.  The trial court denied the writ and SCV appealed.


The court of appeal affirmed the decision of the trial court.  SVC challenged the EIR’s analysis of hydrological and water impacts.

Hydrologic Impacts

On the issues of hydrological impacts, SCV argued that (1) the County improperly defines its own threshold of significance for assessing the impacts; “(2) substantial evidence does not support the Report's finding that the mine's hydrological impacts are minor;” and (3) the mitigation measure is “too nebulous to satisfy CEQA.”

SCV asserted that County erred in using “as a threshold of significance, its own four-part definition of ‘adverse hydraulic impacts’” because “(1) the County may not deviate from the threshold of significance in Appendix G of the CEQA Guidelines (‘Appendix G’) unless it formally adopts a different threshold; (2) even if no formal adoption is required, the Report’s citation of two thresholds makes it unclear which one the Report used; and (3) the County did not in any event explain why it was not using Appendix G’s threshold.”

The court found SCV was incorrect in asserting that formal adoption was required because County’s threshold was specific to this Report and was not for general use.  The court rejected SCV’s argument that it was unclear which threshold was applied.  The Report referred to Appendix G’s factors as factors that could trigger a finding of significant impact, but defined and applied its own “adverse hydraulic impacts” threshold in regard to the Diamond Rock mine.  The court found that this was not ambiguous and the Report was not misleading when it referred to “its project-specific threshold as being ‘under CEQA.’”  Because “CEQA permits an agency to define its own project-specific thresholds . . . any threshold so adopted is ‘under CEQA.’”  The Report was not required to explain why the Appendix G thresholds were not used because those thresholds are only suggestions.  “To require any deviation from them to be documented and justified, as [SCV] suggests, is to elevate Appendix G from a suggested threshold to the presumptive threshold,” which “flatly contradicts both CEQA’s description of Appendix G as only suggested and CEQA’s mandate that agencies have the power to devise their own thresholds.” 

The court further found the Report’s assessment of the hydrological impacts is supported by substantial evidence.  The Report (1) explains that, for the most part, the mine would extract materials from the bed of the river, not its flow, (2) explains why the cumulative prior impact of the GPS mine is relevant in assessing future impacts of both mines, and (3) “explains why the riverbed would be replenished by the surplus sediment that would be deposited by flows passing over previously scoured areas once any upstream pits in the path of the river were filled.” 

SCV contends the Report’s mitigation measure is defective because the “trigger” for “corrective action—‘adverse hydraulic conditions’—is undefined or, at best, inconsistently defined.”  Although CEQA usually requires that mitigation measures be defined in advance, deferral is permitted if “the agency (1) commits itself to mitigation; and (2) spells out, in its environmental impact report, the possible mitigation options that meet ‘specific performance criteria’ contained in the report.”  The court found County had committed to mitigation because it conditioned the issuance of a conditional use report on compliance with the mitigation measure.  The mitigation measure also requires Troesh to “avoid these impacts,” which “necessarily refers to the ‘adverse hydraulic conditions . . . which could result in off-site impacts.’” Finally, the mitigation measure required compliance with the Surface Mining and Reclamation Act and a “condition requiring compliance with environmental regulations is a common and reasonable mitigation measure [Citation].”

Water Impacts

On the issue of water supply, SCV asserts the “Report’s analysis of the Diamond Rock mine’s effect on the water supply of the Cuyama Valley is deficient because: (1) the Report uses the same threshold of significance—31 afy—to assess the project’s individual and cumulative impacts; and (2) the 31 afy standard is out of date.”  The court disagreed finding that “County’s 31 afy threshold of significance assesses cumulative impact,” which “was derived from an examination of the tolerable impact of an individual project on the amount of water available basin-wide.”  Therefore, “the County amply considered the cumulative impact of the Diamond Rock mine on the water supply of the Cuyama River basin.”  The court found the Report lacked an “independent examination” of the mine’s direct, rather than cumulative effects, but found that such examination was unnecessary, because the cumulative threshold is likely more stringent than the threshold likely applicable to the direct impact analysis. 

County found the 1992 threshold remains relevant and its decision is supported by substantial evidence.  Although additional agricultural water usage in the basin has occurred since 1992, after consulting its water agency and examining more recent studies, County “found that the 1992-defined threshold was still valid.”

On the issue of water quality, SCV challenged the Report’s finding that the mine will not have a significant impact on water quality and that Condition 64 will be a feasible means of mitigating any adverse impacts.  The court found that there was no deficiency in Condition 64 because it is a requirement of the conditional use permit and it “sets forth a specific standard, and would be effective in halting exposure of water except in times of seasonal floods (when the pits will be flooded anyway).”

The court, however, agreed with SCV “that the Report’s conclusion that the Diamond Rock mine’s impact on water quality is ‘not significant’ is not supported by substantial evidence.”  The conclusion that the impact is not significant “appears to rest on the Report’s observation that ‘under most conditions, groundwater would be located below the proposed maximum mining depth’ of 90 feet.”  The court noted, “This statement ostensibly forms the basis for the Report’s finding that the groundwater would be exposed infrequently and briefly, and hence for the Report’s conclusion that the mine’s impact on water quality will not be significant.”  However, “this statement is in tension with the data showing that the groundwater in nearby wells is found anywhere between 40 and 110 feet below ground, as well as with other statements in the Report itself recounting the underlying well data.”

However, the court found the insufficiency did not invalidate the Report because SCV failed to establish “that the Report’s unsupported conclusion regarding the severity of the environmental impact is prejudicial.”  The court found no prejudicial error occurred in this case because the Report “sets forth all the pertinent data and follows all the procedures, but comes to the wrong conclusion in classifying the severity of an environmental impact.”  SCV failed to show how the error matters.  “Notwithstanding the Report’s erroneous conclusion that the impact was not significant, the County still insisted that Troesh implement Condition 64.  Condition 64 “obligates Troesh to ensure that no groundwater is exposed—at whatever depth it is encountered.”  The court found that although SCV “contests the condition’s efficacy, it does not dispute that the condition—if feasible—would be wholly effective in negating the mine’s adverse impact on water quality.”  The court stated, “Consequently, on these facts, the Report’s unsupported conclusion regarding significance is of no moment.”

The court held the inconsistency here is not prejudicial because the Report did not inconsistently describe the mine.  “At most, this inconsistency spawned the erroneous conclusion regarding the significance of the mine’s environmental impact.”  However, the court found “any error in that conclusion was not prejudicial.”


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