Differing views of the quarry: Controversy a constant companion as cement makers continue operations

Photo Joe Hu/Town CrierLehigh Hanson Quarry Manager Mike Gantenbein and Community Affairs Manager Sandra James tour the quarry site, located just south of Los Altos and Los Altos Hills. Quarry officials are preparing a new plan that would allow mining expansion. Thus far, the plan has met strong resident opposition.

The sight evokes a reaction that’s slightly less overwhelming than surveying the expanse of the Grand Canyon. Workers are mining a gigantic pit encompassing some 600 acres and plunging more than 700 feet deep into the earth. Huge dump trucks, each capable of carrying 150 tons, cart rock from the bottom. The layering of the rock in the walls of this man-made canyon exposes geologic activity extending over more than 100 million years.

This pit is not in some remote area. It’s located just south of Los Altos and Los Altos Hills, and less than a mile from Cupertino residences.

Welcome to the Lehigh Hanson cement quarry, where the mining of limestone and production of cement has gone on since 1939. The legendary Henry J. Kaiser opened the quarry, which bore his name for decades until Hanson Permanente Cement Inc. undertook control in 1987. A German corporation, Heidelberg Cement Group, assumed operations in 2007, and along with the ownership change came a new name, Lehigh Hanson. It currently employs between 150 and 170 workers at the Cupertino site.


Cement and the environment

Of course, there are natural consequences to mining and making cement: traffic, noise, air pollution and land disturbance. The industrial detritus has led to a history of compliant, although uneasy, relations with the residential communities that grew up around it. Company representatives have used public outreach and education to try to allay fears about health hazards and other long-term environmental impacts.

“We’re trying to answer the public’s questions,” said Marvin Howell, a land-use specialist with Lehigh Hanson.

Plant manager Henrik Wesseling points to the Heidelberg company’s “openness and fairness as soft factors of success.”

They’re quick to address the benefits of the quarry.

“The public rarely understands how much they use our products,” said Howell, who cited the statistic that 70 percent of the cement used in Santa Clara County – 50 percent in the Bay Area – comes from the quarry. “(Being here) means low-cost building materials. If the quarry were not here, (cement) would come from far, far away at far greater cost.”

There also would be additional environmental costs, company officials said, resulting from transporting materials from distant areas.

“No site in the world has closer oversight than this facility,” said Howell, adding that its locally produced cement benefits much LEED-certified (Leadership in Energy and Environmental Design) construction.

But this is little consolation to most surrounding residents who have concerns about environmental hazards and blight.


New reclamation plan

Reclamation – the restoration of the mined areas – has been the quarry’s most visible overture to public concerns about the scarring of the land. The quarry has reclaimed some land, but a new “reclamation plan amendment” – an extension of the quarry’s 1985 reclamation plan – bids to expand mining acreage. The plan will be making news over the next few years because of community meetings and the inevitable resident environmental concerns voiced at the hearings. One was held in Cupertino in October. A second hearing is due sometime in May. A date had not been scheduled as of press time.

Faced with the probability of quarry operations for at least another 25 years, Los Altos Hills resident Bill Almon, an engineer and company owner, wonders whether it’s time to call a halt.

“They shouldn’t have a quarry in a residential area,” said Almon, who has just launched a Web site,, and plans to enlist 5,000 registered county voters in an effort to protest the quarry plan.

Almon, initially drawn to the issue when he discovered residue on his car he believes came from the quarry, said he is concerned about health risks.

He produced a March 2008 report from the environmental group Earthjustice, which listed Hanson at No. 5 among the U.S. Environmental Protection Agency’s top 27 worst kilns for mercury pollution in the nation.

But Sandra James, a former Cupertino City Councilwoman and the quarry’s community affairs manager, said the EPA information, collected in 2006, incorrectly reported readings at twice the actual levels.

“The Bay Area Air Quality Management District has determined that mercury emissions from this plant remain at a safe level and do not pose a risk to the community,” James said.

Measuring pollution

In November, the air quality management district installed an ambient air monitor near the quarry and Stevens Creek Boulevard, which ends at the quarry entrance. The monitor continuously measures particulate-matter levels in the air.

“Our agency is doing some additional testing of fugitive emissions of cement dust and road dust, and any findings will be compared to the most recent Health Risk Assessment,” said Aaron Richardson, a district spokesman. Such assessments are done regularly. “If the exposure numbers are substantially higher as a result of this testing, putting the facility over the 10 in 1 million cancer risk threshold, the Toxic Hot Spots Act would require that the facility notify the public. In such a case, there could also be potential operational ramifications in terms of their air quality permitting requirements. But at this point we are not necessarily anticipating that our testing will result in such increased exposure results.”

Los Altos Hills resident June Strough, who has lived “up the hill” from the quarry since 1965, remembered a time more than 20 years ago when “plumes of smoke” came out of the cement plant. The offending facilities are polluting far less with improvements in technology and after undergoing a change from a wet kiln to dry kiln process in the early 1980s. But Strough is far from satisfied.

“They’re destroying the environment,” she said. “They’re taking the mountain out of here.”

She said she has no faith in the county or other agencies regulating the quarry (“They’re a bunch of limp noodles.”) and added, “There’s no way to stop it but with a big, massive lawsuit.”


Blight factor

James Walgren, Los Altos’ assistant city manager, said the quarry’s impact on Los Altos is primarily visual. In a 2007 letter to county planner Tom Connolly, Walgren said the new quarry plans that indicate expanded mining “may create significant blight within the hillside viewsheds.”

Walgren asked Connolly to address such areas in a draft environmental impact report for the plan. That EIR won’t get under way until quarry officials submit their final application.

The most striking visual, seen from the Los Altos valley floor looking west, is approximately 90 acres of treeless hillside, once a dumping ground, or “overburden” area for quarry rocks found unsuitable, that is currently undergoing a reclamation effort.

“There are two big issues going on here: whether they can operate and the reclamation plan,” said Santa Clara County Supervisor Liz Kniss, who represents the Los Altos-Cupertino area. “There’s no question they can operate – they’re grandfathered in,” which refers to old businesses that can continue to operate because they existed before new laws that would have restricted their operations. “The question,” Kniss said, “is (the final outcome of) the reclamation plan.”

The plan is slowly moving through county channels, with debate centering on the question of operations expansion and the extent of that expansion. An extensive geological study is currently under way.

Expansion concerns

The vast majority of residents speaking at two 2007 scoping meetings and the October hearing are opposed to the new plan. Lehigh Hanson officials delayed plans in 2007 after hearing from residents who felt some of the new mining proposed was too close to homes. The company also discovered it needed to do more geological work.

(For more on the planning process, visit the Santa Clara County Web site,, and search under “Hanson.”)

Existing operations cover 618 acres. The new plan would expand to 917 acres. But quarry officials note 238 acres have been added as buffer lands that won’t be used for mining. That leaves 61 additional acres that could be mined. Quarry lands total approximately 3,200 acres.

James said the added mining acreage does not translate to more limestone production.

“This quarry will never produce more than it has in the past,” she said.

Howell said quarry officials are scheduled to present an application for the preliminary reclamation plan amendment to the county by February 2010, and hope to have final approval by May 2011.

Members of the Committee for Green Foothills said they are keeping track of the plan. Spokesman Brian Schmidt could not be reached for comment.


‘A benign thing’

Almon acknowledged his endgame – shutting down the quarry – is “a big deal.” But he looked ahead, perhaps decades away, when the limestone runs out and the quarry closes, and wondered whether there would be any tree planting or major reclamation at all. In addition, he’s puzzled that “officials treat it as a benign thing. These are all good people (in government). For the life of me, I can’t understand it.”

He seems only half-joking when he suggests renting the blimp at Moffett Field and taking Cupertino and Los Altos council members directly over the quarry.

“It’s the only way they can get a proper view,” Almon said.

Contact Bruce Barton at This email address is being protected from spambots. You need JavaScript enabled to view it..


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