Cemex USA announced it has reached a key milestone in its effort to intensify its gravel mining operations near the San Joaquin River in Fresno County.

Cemex announced Friday that Fresno County has deemed complete its application to modify operations at its Rockfield aggregates plant on Friant Road just north of Willow Avenue and its quarry just south of Lost Lake park.

With the complete application, the county has issued a Notice of Preparation for the project’s Environmental Impact Report, according to a news release from Cemex.

The quarry and plant are used to produce aggregate, which is a key component in construction materials such as concrete and asphalt. The facilities have been producing aggregate since 1913. Cemex, a Mexican multinational building materials company, has operated them since 2005.

Cemex said it doesn’t plan to expand outside of its current boundaries, but that it would transition from mining sand and gravel from the river bed to hard rock, and mine at a deeper depth — 600 feet below the ground surface.

Cemex officials said they also plan to invest in more modern plant equipment to improve efficiency and “site aesthetics,” and also include more national open space, woodlands and riparian habitats as part of its reclamation plan at the conclusion of its 100-year mining plan.

Francisco Rivera, Cemex USA regional president for the California region, stated: “For many years, CEMEX’s Rockfield Quarry has provided a valued source of high-quality construction materials, economic activity and jobs. CEMEX is proud to be a longstanding contributor in the Fresno community, and we look forward to working with Fresno County on the next steps of this plan that will help us continue to support local projects and the local economy for years to come.”

The Rockfield area operations directly support more than 90 full-time employees in Fresno County, including its processing plant and quarry operations, concrete ready-mix plants and administrative offices.

The project is sure to draw controversy, as did Cemex’s plan to mine Jesse Morrow Mountain east of Fresno along Highway 180 before it was scrapped due to opposition from community members and eventually Fresno County supervisors.

For more information on the proposed plan and project updates visit cemexusa.com/Rockfield