DIAMOND BAR, Calif. (CNS) — More than two-thirds of the warehouses in Southern California required to comply with an air-quality rule have not done so and could face penalties up to $11,710 per day, the South Coast Air Quality Management District announced Wednesday.

In May 2021, the AQMD passed the Warehouse Indirect Source Rule, which requires warehouses greater than 100,000 square feet to take actions to reduce nitrogen oxide (NOx) and diesel particulate matter (PM) emissions or to otherwise limit exposures to air pollution in nearby communities.

Overall, 2,000 warehouses are subject to the two-year-old rule, with 1,400 of those currently out of compliance, according to the regulatory agency.

“Time is up for those not complying with our rule,” SCAQMD Executive Officer Wayne Nastri said. “Owners and operators of warehouses have known about these deadlines for two years. Communities near these facilities deserve to breathe clean air and our enforcement teams will work quickly to ensure that the facilities come into compliance as quickly as possible.”

Warehouses are a key destination for heavy-duty trucks and have other sources of emissions such as cargo handling equipment, all of which contribute to local pollution. Emissions from sources associated with warehouses account for almost as much NOx emissions as all of the refineries, power plants and other stationary sources in the South Coast Air Basin combined, the AQMD said.

The agency determined that those living within a half-mile of warehouses are more likely to have higher rates of asthma and heart attacks and must endure a greater environmental burden. The clean-air rule is expected to reduce smog-forming emissions by 10%-15% from warehouse-related sources, according to the AQMD.

Since the rule passed in 2021, the agency has been identifying and reaching out to warehouses, providing them with information, training and assistance to ensure compliance with the rule. This week, the agency issued a compliance advisory to warehouse owners and operators advising them of rule requirements and past deadlines.

The SCAQMD’s enforcement team is preparing to issue notices of violation that can result in daily penalties and further legal action. The agency will first focus on warehouses located in Environmental Justice communities — lower-income communities that bear disproportionate harm from pollution, including neighborhoods surrounded by freeways and industrial facilities.