Nammo Defense Systems Facility, Mesa, AZ
Background
Nammo Defense Systems operates a munitions manufacturing facility in Mesa, Arizona. The facility began manufacturing in the 1960s as Talley Industries Inc. (aka Talley Defense Systems) and the Nammo Group purchased the business in 2007.
Previous manufacturing caused groundwater contamination of perchlorate and other substances. Perchlorate is both a naturally occurring and manmade substance that is harmful to human health. Perchlorate is an ingredient in rocket fuel, munitions, and explosives. Currently, contamination from this site does not impact public drinking water.
The facility began environmental study and cleanup efforts in the 1990s. In February 2021, Nammo signed an Administrative Order on Consent (“Order”) with EPA. In the Order, Nammo agreed to cleanup contamination caused by perchlorate and other substances. EPA’s role is to administer the Order and oversee the environmental study and cleanup that Nammo performs.
Current Cleanup Work
Nammo currently operates interim groundwater cleanup. The facility pumps groundwater from the ground and removes contaminants. Under the Order, Nammo must continue the current groundwater treatment. Nammo must also conduct a detailed environmental study of the entire facility. EPA will decide what additional cleanup the facility needs based on the results of that study.
Coordination Efforts
The Arizona Department of Environmental Quality (ADEQ) is the State of Arizona’s environmental agency. Nammo elected to participate in ADEQ’s Voluntary Remediation Program in 2019. The ADEQ oversees Nammo’s study and cleanup of groundwater on the southern side of the facility (former Plant 3 area). Please contact the ADEQ for more information on the Plant 3 investigation. EPA oversees environmental study and cleanup for the rest of the site.
The Salt River Pima Maricopa Indian Community is a federally recognized Tribe with land located next to the Nammo facility. EPA coordinates with the SRPMIC on the study and cleanup. EPA oversees the Order and coordinates the study and cleanup among all the parties.
Future Work
EPA is currently reviewing Nammo’s proposed plans for investigation. The plans cover the study of soil and groundwater. Nammo will complete the environmental study after EPA review. EPA will use the results to decide what Nammo must do to finish the cleanup. EPA will provide the public opportunities for input before deciding the final cleanup actions. EPA will update this website when public input opportunities are available.
Order on Consent
Nammo Defense Systems, RCRA 3008(h) Order on Consent and Appendices (pdf)