Hexavalent Chromium in the City of Paramount


Air monitoring for hexavalent chromium or chromium 6 and other toxic air contaminants in Paramount has been on-going since late 2013 when the South Coast AQMD responded to community complaints of metallic odors thought to be coming from a metal forging and grinding operation in Paramount. Since then, air monitoring in the area has expanded, and SCAQMD has identified several other industrial facilities potentially contributing to the problem.

What has been found through air quality testing?

In October 2016, monitoring near the intersection of Minnesota and Madison streets revealed chromium 6 levels much higher than in other areas of Los Angeles County. This finding lead to the expansion of air monitoring to the City's southeast industrial area and school zones, as well as into northern Long Beach in 2017.

The southeast industrial area has shown chromium 6 levels up to 50 times higher than in other areas of Los Angeles County. Average Chromium 6 levels in the city of Paramount have improved substantially since 2016. However, they still remain above the average levels seen in the central and southern regions of Los Angeles County (0.04 to 0.06 ng/m3). There are occasional brief elevations in the levels due to equipment repairs, loss of power for emission control devices, and other malfunctions. Please see the Figure below.

Figure - City of Paramount Hexavalent Chromium 6 in Outdoor Air 2016-2021
Source: South Coast Air Quality Management District, 2016-2021
Figure - City of Paramount Hexavalent Chromium 6 in Ambient Air Nov 2021 - Mar 2022

You can find additional information on the South Coast AQMD on-going air monitoring activities and Summary of Efforts in Paramount.

What has been found in indoor and outdoor air at selected schools?

The Paramount Unified School District (PUSD) has conducted periodic testing for chromium 6 since 2017. In September 2018 and August 2019, PUSD partnered with the Los Angeles County Department of Public Health (DPH) to test air and dust inside of two schools located near chromium 6 facilities, Gaines and Lincoln Elementary.

In September 2018, chromium 6 was detected in air samples in two of four classrooms tested: 0.04 ng/m3 at Gaines and 0.06 ng/m3 at Lincoln.

In August 2019, chromium 6 was not detected in any air samples from four classrooms tested, two at Gaines and two at Lincoln.

Overall, these results indicate an apparent improvement in the presence of chromium 6 in the air of the classrooms tested. However, continued monitoring is needed to ensure these improvements are maintained and to detect any changes to these levels in the future. The sampling reports can be accessed.

Sampling for Chromium 6 at a Paramount school
Sampling for chromium 6 at a Paramount school

What is being done to address the high levels of chromium 6 in Paramount?

Local and state agencies have worked to identify facilities that produce chromium 6, and to lower the amount of chromium 6 that they release. Since November 2016, DPH and SCAQMD have issued Public Health Directives and Orders for Abatement to businesses in Paramount and North Long Beach related to chromium 6 emissions and/or odors. These facilities include Anaplex, Aerocraft, MattCo Forge, Press Forge, Weber Metals, Carlton Forge Works, and LubeCo. The SCAQMD has been developing and implementing new air quality rules to regulate chromium 6 in metal processing facilities. In addition, the City of Paramount has adopted revised zoning rules for metal processing operations to reduce emissions.

Business Resource Fair
Business Resource Fair

DPH and the City of Los Angeles Department of Public works have also collaborated successfully to promote the use of alternative technologies to chromium 6. On January 23, 2019, both agencies held a Metal Finishers Technology Symposium and Business Resource Fair at the Los Angeles Trade-Tech College. A total of 76 event attendees including metal finishers, metal platers, speakers, City staff attended the Symposium and Business Resource Fair. Forty-three metal finishers and platers from both the City and the County attended. The Symposium included presentations on hexavalent chromium alternatives, trivalent chromium and waste reclamation strategies, and technologically advanced wastewater treatment solutions from industry leaders. The Business Resource Fair provided information on best management practices, potential technologies on water conservation, technical assistance, and available financial incentives to the attendees.

Metal Finishers Symposium
Metal Finishers Symposium