MARINA, Monterey County (KPIX 5) — The smokestack is visible from scenic Highway 1, sticking out from the sand dunes near Marina in Monterey County. Behind the dunes is the last beach sand mining operation in the United States.

The CEMEX Lapis Sand Mine still going strong after 100 years in business, but it may not be open for much longer. The California Coastal Commission wants the mine shut down over environmental concerns such as beach erosion.

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“It’s good news for the entire Monterey Bay and the coast of California,” said Ryan Kallabis of Save Our Shores in Santa Cruz. “Closing the CEMEX plant in Marina is going to reduce the environmental impact that we have with erosion rates and it’s going to reduce the economic impact that we see from that erosion.”

The plant first began operating in 1906. It was grandfathered in to the California Coastal Act in the 1970’s and allowed to stay in operation. The heart of the mining operation is a large pit on the beach that traps san and sea water at high tide. About 20,000 dump trucks worth of sand is extracted from the mine every year to be used in industry as well for recreation such as golf courses and playgrounds.

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But environmental groups say removing that much sand is speeding up erosion along the coast. Save Our Shores says Monterey Bay already has the highest beach erosion rates in California.

CEMEX employs about 20 workers in Marina. A company spokesperson said in a statement that CEMEX is reviewing the Coastal Commission’s letter and disagrees with its assessment. “The mine is operating in an environmentally responsible manner and is following the laws and regulations,” according to the statement.

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The company plans to fight efforts to shut it down and stay in business.