The Apache Powder Company site sits in Cochise County, Arizona, near St. David. The facility began operating in 1922, making industrial chemicals and explosives, then later shifted to agricultural and mining products. Those decades of activity left behind liquid and solid wastes that contaminated both soil and groundwater. The site was added to the National Priorities List in 1990.
EPA identified 18 contaminants of concern across soil and groundwater. They include metals such as arsenic, lead, chromium, beryllium, and manganese. Organic compounds like 2,4-dinitrotoluene, 2,6-dinitrotoluene, and naphthalene are also present, along with inorganic compounds including nitrate, perchlorate, and fluoride. Arsenic and nitrate appear in both soil and groundwater, and arsenic and fluoride were found specifically in groundwater.
EPA selected the main cleanup remedy in September 1994. It called for pumping and treating perched groundwater and the shallow aquifer using constructed wetlands, then recharging treated water back into the aquifer. Contaminated soils were either capped on-site or excavated and disposed of off-site. EPA updated the remedy in 1997 for more flexibility and issued a Record of Decision Amendment in 2005 that added monitored natural attenuation and refined institutional controls. Construction of the cleanup systems finished in September 2008. Final remedial action ran from October 2017 through September 2021. Apache Nitrogen Products, Inc. operates an Alternative Domestic Water Supply Plan and a Community Outreach Plan, both updated annually.
As of the latest data, human exposure is under control and groundwater migration is under control. The site has achieved sitewide ready-for-anticipated-use status, meaning all cleanup goals for current and reasonably anticipated future land uses have been met and required land-use restrictions are in place. One on-site business operates at the property, employing 75 people and generating an estimated $48,120,000 in annual sales. The site remains under long-term response action and operation and maintenance, and has not yet been deleted from the National Priorities List. The most recent five-year review was completed in September 2022, with the next one estimated between September and November 2027.
Community members who want to stay involved can contact the EPA Community Involvement Coordinator or Remedial Project Manager. Paper copies of the site's Administrative Record are available at the Buckeye Library in Buckeye, Arizona, and at the EPA's Superfund Record Center in San Francisco, California.
