What Is the CEMEX Mine? How Drilling Could Threaten Fresno’s Air and Water

A multinational company called CEMEX wants to blast a pit 600 feet deep in their Rockfield Quarry Site—enough to bury a 50-story building—right next to the San Joaquin River. Not only that, but this company wants permission to keep doing it for the next 100 years. Here’s what that means for the air you breathe, the water you drink, and what you can do about it.

What is CEMEX?

CEMEX is a multinational building-materials company with a long history of environmental damages and regulatory evasion.¹ It mines aggregate: the sand, gravel, and crushed rock used to make concrete and asphalt for roads, housing, and development. Near Fresno, it runs the Rockfield quarry site and the processing plant site along Friant Road, just south of Lost Lake Park.

CEMEX has a long, documented, and consistent record of pollution violations, regulatory evasion, and environmental damages across the United States:

• • In 2016, the company agreed to a federal settlement with the U.S. Environmental Protection Agency and the Department of Justice, investing roughly $10 million in pollution controls and paying a $1.69 million civil penalty to resolve alleged Clean Air Act violations at five cement plants across four states.²
  • In a separate case, CEMEX agreed to a $1.4 million penalty and an estimated $2 million in pollution controls for Clean Air Act violations at its plant in Fairborn, Ohio—violations tied to emissions linked to childhood asthma and smog.³
  • As recently as 2026, neighbors and public-health advocates in Lyons, Colorado, were still fighting to shut down an aging CEMEX kiln they describe as a growing threat to community health.⁴
  • In the United States alone, they’ve been caught on 82 environment-related offenses and have been fined more than $45 million. (5)

Their track record paints a clear picture: CEMEX will do anything to make themselves richer at the cost of our environment, our health, and our economy. It’s clear that they can’t be trusted to “safely” blast bedrock beside a river in a valley with some of the dirtiest air in the country—and they certainly can’t be trusted to do it for 100 years.

What is CEMEX actually proposing?

There are two things happening at once, and it’s worth keeping them straight:

First, CEMEX wants to expand into deep-rock mining: drilling and blasting as deep as 600 feet into solid bedrock beside the river. This would likely be the first use of explosives for deep mining anywhere along the San Joaquin River. (6) The company is asking to do this for another 100 years—even though it is planning to service Fresno County for only 10 years.

This new deep-rock mining project would pollute the air and water of the Central Valley, more specifically Fresno County and Madera County, for the next 100 years and make taxpayers pay for the damages to our health and public infrastructure from air pollution, additional traffic congestion, and more. 

Second, CEMEX is seeking to keep its current operations running while that expansion is reviewed and it has leaned on an environmental study from the 1980s to justify it. Critics, including the City of Fresno’s own planning director, argue that an analysis nearly 40 years old can’t possibly reflect today’s traffic, air quality, or drought conditions. (7)

How does this affect you and your family?

This is about more than keeping the San Joaquin River clean—it’s about keeping Fresno’s families safe and healthy.

Your water during an ongoing drought

The Central Valley depends on underground aquifers of groundwater, and that groundwater is already stressed by drought and contamination. Deep drilling and blasting near the river can disrupt and contaminate the underground aquifers that families and farms rely on to drink and grow food.

Your air in a region that can’t afford more pollution

Fresno County is the top agricultural producer in the entire United States. Yet we also consistently rank as one of the most polluted counties in the country, year after year. (8)  Families here breathe more pollution, kids go to the emergency room with higher rates of asthma, and far too many people in the Central Valley die from diseases tied to dirty air.

Blasting bedrock the way CEMEX plans to will release fine particulate matter—the kind of microscopic pollution and toxic emissions linked to asthma, heart disease, and cancer.

This isn’t speculation. CEMEX’s own Draft Environmental Impact Report acknowledges that the project’s emissions “may exceed cancer risk thresholds.” (9) 

On top of that, more mining means more diesel trucks in Fresno County. This extra traffic congestion creates more dust, more noise, and more pollution for nearby neighborhoods.

Your river and the places you go

The San Joaquin is California’s second-longest river and a designated recreation and wildlife habitat corridor. The proposed pit threatens the wildlife habitat nearby—and could have permanent impact on the bike trails, recreation areas, and scenic views that make Lost Lake Park and the San Joaquin River a public outdoor space that’s friendly and safe for Fresno families.

Why this matters now

The long and short is this: A company with a documented history of environmental violations is asking Fresno County to sign off on a century of blast mining beside a river for 100 years—partly on the strength of a study that’s already nearly 40 years old.

The CEMEX project would put the Central Valley community’s health on the line and put taxpayers on the hook for the cost. If they get their way, they’ll rake in profits while Fresno’s tax dollars go to fix the public infrastructure they damage. 

The good news: decisions like this are made in public, and public pressure works. This is exactly the kind of fight communities win when enough people show up.

What you can do

This goes deep, because we’re not fighting just one project in the Central Valley. We’re fighting a billion-dollar corporation with a long history of environmental destruction.

The people of Fresno deserve clean air, safe water, and an affordable future—and you can help make that possible with two simple steps:

Step 1 (Easy): Sign our petition to tell Fresno County to reject CEMEX’s proposal.