The U.S. Environmental Protection Agency (EPA) and Asarco announced an agreement in early November requiring the company to spend $150 million to install new equipment and pollution control technology to reduce emissions of sulphur dioxide (SO2) and toxic heavy metals at the company’s copper smelter in Hayden, Arizona. The company will also fund local environmental projects valued at $8 million, replace a diesel locomotive with a cleaner model for $1 million, and pay a $4.5 million civil penalty.

Asarco said it will undertake a converter retrofit project at a cost of more than $128 million that will increase sulphur capture-and-control efficiency from 95% to 99% and will result in the Hayden smelter being one of the cleanest in the world. New and upgraded ventilation hoods will be installed to capture hot flue gases from the furnaces. An aging electrostatic precipitator will be replaced by a new, cleaner baghouse, and high-performance lime will be injected to reduce SO2 emissions.

In addition to SO2 emissions, the EPA action targeted hazardous air pollutants, including lead and arsenic, and particulate matter. With new controls in place, hazardous air pollutants should be reduced by at least 8.5 st/y and particulate emissions by 3,500 st/y, the EPA statement said.

To reduce wind-blown dust from the facility, which contains varying levels of heavy metals, Asarco will implement an improved dust control plan, including the use of wind fences, upgraded water sprayers, and the installation of concrete pads. The company also will operate five ambient-air monitors in and around the Hayden and Winkelman communities to track levels of pollutants, including arsenic, lead, and particulate matter, and will make additional improvements to dust controls if levels are high.

Asarco also will spend $6 million on a road-paving project in Pinal county to reduce dust pollution from local dirt roads and will provide $2 million to Gila County Environmental Health Services to conduct lead-based paint testing and abatement in homes, schools, and other public buildings in the towns of Hayden and Winkelman.

Jack Garrity, technical tervices manager at the Hayden smelter, commented, “We believe we can accomplish the project safely and in an environmentally sound fashion while continuing to operate the smelter at normal capacity.”

Asarco is owned by Grupo México. The Hayden plant includes a crusher, concentrator, smelter, and tailings impoundment areas. The plant produces 300 million to 400 million lb/y of copper and more than 500,000 st/y of sulphuric acid.

Discussions between Asarco and the EPA on an agreement to resolve regulatory issues at the facility and to allow the converter retrofit project to proceed have been ongoing for almost four years. The pollution controls projects will take three years to complete.