City report: three consecutive hexavalent‑chromium exceedances triggered South Coast AQMD action and NOVs to two foundries

Randall Baxter, project manager for Trinity Consultants, told the Paramount City Council on Nov. 18 that the city’s six‑site hexavalent chromium monitoring network recorded three consecutive exceedances in August and September at the industrial sampler near 15701 Minnesota Avenue, which triggered South Coast Air Quality Management District (AQMD) action.

"If there's an elevated reading above 1 nanogram, it's considered it's above background levels," Baxter said, describing the network’s 24‑hour, 1‑in‑6‑day sampling schedule and the monitoring locations. He reported exceedances at the Minnesota Avenue site on Aug. 5 and three consecutive exceedances on Sept. 8, Sept. 15 and Sept. 22; Vermont Avenue also recorded an elevated reading on Sept. 15 and again in mid‑October.

Those three consecutive exceedances, Baxter said, led South Coast AQMD to investigate. "They ended up issuing two notices of violation … to Feninco, LLC and ProCast Industries," he reported, and AQMD conducted mobile monitoring and on‑site inspections as part of the response. AQMD told staff the facilities must obtain required permits for metal‑processing equipment, perform source testing for hexavalent chromium emissions and clean areas within 20 feet of melting operations, Baxter said.

City staff told council the city’s code enforcement division also issued notices to the same two businesses and has been coordinating investigative steps with AQMD, including on‑site visits to review permits and equipment. Staff said one facility has cooperated and facilitated a site tour; the other facility had replied by email but had not yet scheduled an inspection as of the Nov. 17 staff update.

Baxter recommended staffing and technical changes to improve local meteorological data: the tripod meteorological station on City Hall is informative but not sited to federal EPA "siting" criteria and can be affected by nearby trees. He said a 10‑meter tower at a less obstructed site would yield legally applicable wind data and make local dispersion analysis more representative than relying on Long Beach Airport data, which is more than five miles away.

The consultant also described South Coast AQMD’s proposed Rule 1435 (fenceline monitoring for certain class‑4 metal‑processing facilities). Under that proposal, class‑4 facilities with large furnace capacity would be required to implement fenceline monitoring with multiple sampler heights, wind sensors and routine reporting; Baxter said AQMD expects facilities that opt in to face a multi‑phase schedule with technical benchmarks.

City staff said the monitoring network has recently replaced older samplers with new ARA LFR6 samplers and that the lab turnaround and portal publication processes are in place; staff will continue to coordinate with AQMD and update monitoring data on the city's environmental portal (paramountenvironment.org/air). Council members asked about AQMD’s rule timing and whether the observed events might affect rule development; staff said they were working with AQMD and would post additional information as it becomes available.

What happens next: staff said they will continue inspections, coordinate with AQMD on source testing and permitting, and post AQMD updates to the city’s environmental portal.