[Note: the following memo was shared for posting on the Davisite]
To: Clancy McConnell, David vanRijn
cc: Yolo County Planning Commission (via Jeff Anderson), Phil Pogledich
From: Alan Pryor, Chair, Sierra Club Yolano Group
Date: October 26, 2026
Re: A Subsequent EIR is Required for the Vulcan Mining Permit Extension instead of just an Addendum to the Previous EIR
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Executive Summary
Under the California Environmental Quality Act (CEQA), when a project changes or new information emerges after an Environmental Impact Report (EIR) is already certified, lead agencies must use a specific legal framework to determine if further environmental review is necessary. Yolo County has determined that just an Addendum to the 1998 SEIR for the Syar-Vulcan Madison Mine is required to extend the operating permit for that mine from 2029 to 2049.
We strongly disagree with this determination believing instead that a Subsequent EIR must be prepared. This is because new information has arisen regarding a plethora of more severe adverse environmental impacts that have occurred at the Vulcan and other Cache Creek off-channel mining sites since the 1998 certification of the SEIR for the Vulcan Madison mining project. This new information requires disclosure and analysis in a Subsequent EIR subject to public circulation.
These adverse environmental impacts for which additional information has arisen include widespread unresolved methyl mercury contamination of the deep wet impoundment pits at the Madison mine and other mining sites along Cache Creek site.
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