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'Environmentally concerning' cement plant to close for good, thanks to pressure from Santa Clara County – Palo Alto Online

Palo Alto Online

A cement plant and limestone quarry in the Santa Clara County foothills will permanently close after more than three years of paused production because of the COVID-19 pandemic and amid pressure from the county.
The Santa Clara County Board of Supervisors voted Tuesday to accept a legally binding agreement with Lehigh Southwest Cement Company to close the quarry and cement plant for good.
Limited quarry work will still allow the company to process previously extracted materials into aggregate, but no further limestone will be extracted.
Lehigh extracted limestone and greenstone from the quarry, which is mostly in an unincorporated area. Three-quarters of the 3,500-acre property is unincorporated county land; the other acres are part of the cities of Cupertino and Palo Alto.
Lehigh, owned by multi-national corporation Heidelberg Materials, processed the raw materials into cement and construction aggregate at an adjacent facility on the property.
The limestone stock at the existing quarry was depleted years ago and the cement plant has been shuttered since April 2020 due to the COVID-19 pandemic.
In 2019, Heidelberg submitted a reclamation plan for the site that indicated it had plans to expand quarry operations by removing a hilltop that is protected by an easement with the county.
After pushback from the county Board of Supervisors, Heidelberg announced that it would not restart operations at the site.

But Supervisor Joe Simitian, who represents the county’s District 5, where the quarry is located, said he wanted assurance that the company’s decision would not be reversed in the future and sought a legally binding agreement that would ensure the quarry and cement plant do not resume operation beyond processing the aggregate that has already been extracted.
That process does not involve use of the kilns at the cement plant, which will be demolished.
Simitian said he thought it was necessary to have a legal agreement so that the decision is not reversed in the future if the company changed its policy.
“I’m pleased with this outcome,” Simitian said. “I’ve pushed for a standalone agreement shutting down the cement plant because it guarantees closure — right now, and forever — in a way that’s legally binding.”
The company had been cited by the county 2,135 times and fined tens of millions of dollars from 2012-2021 for various violations including water discharge into Permanente Creek, air quality, noise, and other violations.
The company pointed out to the county that not all alleged violations were substantiated, but it nonetheless agreed to make the closure legally binding after the county threatened to withdraw its use permit. The agreement allows the continuation of the aggregate processing for the next 18 months.
A reclamation plan to restore the area to its natural habitat is scheduled to take 40 years to complete. The work will involve backfilling the quarry, replanting native vegetation, regrading and restoring natural drainage on the property.
Julie Hutcheson, incoming executive director for the environmental nonprofit Green Foothills, lauded the agreement.
“This milestone marks a significant step toward addressing long-standing environmental concerns. We look forward to working together toward the restoration of this landscape for the benefit of people and wildlife,” Hutcheson said.
Backfilling the quarry will require about 42 million cubic tons of fill, which will consist of greenstone previously extracted from the site, and other, off-site material.
Great news! Good job, Supervisor Joe Simitian!
I have biked past there multiple times heading up Monte Bello road. I guess it is a good thing to have it shut down, but was a reminder that all the cement and limestone that we use does come from somewhere. Usually these places are out of sight and out of mind, but this one was right in the middle of a nature preserve.
Our Santa Clara County officials, who cannot construct a proper 2023 budget so they can lower our property taxes, should be focused on attracting more businesses to the county reversing the California trend of companies exiting the state and taking their jobs with them.
As the politicians celebrate the closing of the cement plant, there will be one less so prices for projects, both corporate and municipal, will increase.
There is no such thing as a cubic ton, but regardless, where will all this mass come from? Think of the environmental harm in mining at other locations merely to backfill an existing mine. When the source mines are depleted, additional source mines will be required!
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