Demolition is scheduled to begin at the controversial Permanente Quarry and cement plant near Cupertino after years of planning. The plant stopped operations in April 2020 and was scheduled to close permanently in August 2023 following pressure from the county. Throughout the operation of the plant, several environmental and governmental agencies filed lawsuits against the quarry for discharging toxic metals and violating water, air, and noise pollution standards. After securing a contractor and obtaining the necessary permits, the demolition will start this month and is scheduled to be finished by early 2028, according to a release from Heidelberg Materials North America, the multi-national corporation that owns the plant. The contractor will level approximately forty structures across 123 acres.
David Perkins, Heidelberg Materials senior vice president of sustainability and public affairs, stated in the release that since formally announcing the permanent closure of the cement kiln in 2022, the company has prioritised listening to residents, businesses, and other local stakeholders to gather feedback on how the site could provide long-term value to the community. He noted that the commencement of demolition marks a significant step forward in this process. Since its purchase by Henry J Kaiser in 1939, the Permanente Quarry and cement plant contributed to building projects in Northern California, including landmarks such as the Shasta Dam.
The Sierra Club was the first to file a lawsuit in 2011, alleging the quarry was illegally dumping toxic metals into Permanente Creek. Lawsuits from the United States Environmental Protection Agency and the State of California followed in 2015. Santa Clara County also found a variety of violations with the plant and issued more than two thousand citations from 2012 to 2021. In 2020, plant operations paused due to the pandemic, and amid continued pressure from the county, the quarry and plant closed permanently in 2023. In efforts to restore the area, county officials broke ground on the Permanente Creek Restoration Project in July 2025 to remove toxic mine waste and restore miles of watershed in Cupertino.
Cupertino Mayor Kitty Moore said in the release that this has been a long-awaited transition and an important opportunity for the city to prioritise the health, safety, and quality of life for residents. Santa Clara County Supervisor Margaret Abe-Koga honoured the past contribution of the site to the state but said now is the time for change. Abe-Koga stated that she looks forward to this important step in the next chapter of the quarry and its restoration, adding that she values the collaboration and open dialogue of Heidelberg Materials as it honours its promises to the public and embarks on reclaiming the site.
