Carlton Forge Works

Background & Facility Information

Carlton Forge Works (CFW) located at 7743 Adams Street in Paramount, California (SCAQMD Facility ID No. 22911) produces seamless rolled rings and open die forgings for the aerospace, gas turbine, industrial, commercial, and nuclear industries using carbon and alloy steels, aluminum, titanium, nickel, cobalt, chromium and other high-temperature metals. CFW primarily manufactures rolled rings by open-die forging and some forged parts by closed-die forging. CFW receives the alloys and cuts them to the correct weight. After cutting the parts, they are sent to grinding to remove sharp edges.

The process requires heating the metals to allow the metal to be formed into rings or other specified forms required by CFW’s customers, but the metal is not melted or poured. Once the parts are heated to the appropriate temperature, they are forged into the desired shape. The parts may be sent to grinding during or after the forging process to remove sharp edges or cracks that might develop. After the final forging process, the parts are sent off site for various post-processing operations. The parts are then inspected and shipped to the customer. Grinding generates metal dust at 25 grinding booths in the grind building; emissions from these operations are captured and passed through one of three baghouses that have 99.5% control efficiency. The grind building has been verified to be a permanent total enclosure using EPA Method 204.

AB2588 & Rule 1402 Activities 

In accordance with AB2588 and SCAQMD Rule 1402, SCAQMD staff notified Carlton Forge Works on March 21, 2014 that it must submit an HRA based on its 2012 Air Toxic Inventory Report (ATIR). The HRA prepared for this request was submitted on August 18, 2014, with a revised version submitted on October 28, 2014. This revised HRA was subsequently reviewed by SCAQMD staff and the Office of Environmental Health Hazard Assessment (OEHHA).

Simultaneously, in order to investigate air quality complaints alleging that Carlton Forge Works was the source of burning metallic odors, in mid-2013 District staff initiated an assessment of air quality in the Paramount area, including inspections of industrial facilities, placement of glass plates to collect dust particles, and placement of air quality monitors in multiple locations near Carlton Forge Works to measure the level of metals in air.  The air monitoring data available from this investigation is particularly useful for the AB2588 HRA submitted by Carlton Forge Works as the monitoring provides actual ambient levels of pollutants found in air, whereas the HRA is based on a modeling analysis. The monitoring data can therefore be used as an independent check to determine if the modeling analysis included all emission sources, including fugitive emissions (e.g., emissions not coming from a stack).

Although Carlton Forge was required to prepare its HRA using 2012 emissions, monitoring data was not available from that time period. District staff therefore reviewed the oldest data available, from August 8, 2013 through August 7, 2014, as part of its evaluation of the dispersion modeling analysis in the HRA. Importantly, early in this time period, CFW voluntarily installed controls to reduce fugitive emissions from its grinding operations. Some metals, such as nickel (a key component of some alloys processed by CFW), show a notable reduction in concentration at the same time that the fugitive emission controls were installed at CFW. This clear relationship indicates that before controls were installed (e.g., in the 2012 base year), fugitive emissions from the grind shop were a much larger contributor to ambient pollutant levels measured at the nearby monitor than today.

SCAQMD is continuing to investigate metal emissions in the Paramount area, in particular with respect to hexavalent chromium (including with a new temporary monitor that CFW has allowed the District to place on its property). If there are additional sources of hexavalent chromium or other metals that have not yet been identified but are attributed to CFW in the future.

Public Notification Meeting

  • Date & Time:     November 10, 2016 at 6:00 pm
    Location:              Gateway Cities Council of Government
                                      16401 Paramount Blvd., Paramount, CA 90723 

  • Public Notice in English or Spanish

  • SCAQMD Presentation (11/10/16, pdf 2.2 MB)

Health Risk Assessment Documents

Additional Information

Page Modified November 16, 2016

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