Water is essential to life on Earth, covering roughly 71 percent of the planet. In southeast Missouri, where Doe Run operates, water sustains diverse plant and animal life, and supports fun activities, such as fishing, swimming and floating. Doe Run continually explores ways to manage the water present in its operations as part of its commitment to being a good steward of this important natural resource.
In 2014, Doe Run invested approximately $7 million on water treatment research and construction costs at its Southeast Missouri Mining and Milling Division (SEMO).
An estimated 38 million gallons of water flow naturally into Doe Run’s six mines and other facilities daily. As part of addressing significantly more stringent water quality standards, an advanced water treatment plant (similar to a municipal water treatment plant) began operating at Brushy Creek Mine and Mill. It collects and treats the water to meet discharge standards before it’s returned to nearby streams.
“We are diligent with our water treatment, and complete tests to confirm that the water meets water quality standards,” said Kevin James, Doe Run environmental engineering supervisor. “One way we quality–test treated water is to make sure that even very sensitive species can thrive in it. While this may seem unimportant to humans, it is an important part of the water ecosystem.”
Throughout its first year of operation, it became apparent that the Brushy Creek water treatment plant had potential to treat an even greater volume of water than originally anticipated. Doe Run worked with the plant designers to carefully analyze the flow of water through the treatment process, and identified opportunities for processing improvements in the system. The plant designers proposed alternative equipment, such as larger water pumps, that could accommodate higher volumes.
“The Brushy Creek plant originally cost approximately $8 million to build, but by investing an additional $500,000 in modifying the plant’s design, we almost doubled its capacity to accommodate additional water volume,” said Dan Buxton, project manager at SEMO. “This helps us to meet our responsibilities to the environment and our communities, as well as support the financial health of our business.”
Because the water at each mine is unique, different technologies may be deployed to meet the needs of a particular mine. For example, the Brushy Creek water treatment plant runs a flocculation process in which chemicals encourage metal particles to cluster together to settle out of the water before it is released. A similar water treatment plant is being constructed at Buick Mine and Mill and will begin operating in 2015.
Doe Run’s water treatment efforts resulted in improvement at all divisions in 2014. The total amount of lead and zinc in discharged water from all Doe Run facilities decreased by approximately 25 percent and 22 percent respectively.
A pilot plant tested a different water treatment process in 2014 for use at other locations, including No. 29 Mine. The process, called electrocoagulation, removes metal particles from water using electrical currents. In 2015, the Glover and Herculaneum facilities will test electrocoagulation for the treatment of water at the site.
Doe Run also is exploring ways to manage surface water at its mine and mill sites. In 2014, the company built a retention pond at No. 29 Mine that collects storm water runoff. The water is then pumped to a series of collection basins where metals and impurities settle out.
Protecting minerals in our care, especially concentrates, is another component of Doe Run’s environmental programs. The company invested approximately $23 million on construction of concentrate enclosures and baghouses at its mills since 2011. In 2014, Doe Run spent approximately $6.8 million to add a concentrate enclosure and baghouse at Sweetwater Mill. Like those installed at Brushy Creek Mill in 2012 and Buick Mill in 2013, the enclosure and baghouse reduce the potential for emissions from concentrate handling. The enclosures also help maintain the quality of milling concentrates by protecting them from wind, rain and snow. Plans are underway to construct the final concentrate enclosure and baghouse at Fletcher Mill in 2015.
Brushy Creek Enclosure
Brushy Creek Baghouse
Resource Recycling Baghouse
Innovation by SEMO’s environmental team and Doe Run’s information technology team also improved efficiency and accuracy for collecting water sample data. Together, the teams created a customized laboratory information management system (LIMS) that improved data tracking.
“Previously, a lab technician manually entered the water sample data into a spreadsheet,” said Amy Sanders, environmental compliance supervisor. “Now, that data from the water samples is automatically transferred from lab machines to the new LIMS database, reducing time and the chance of human error. As a result, we can analyze the water sample data earlier, and respond quicker to make any necessary adjustments to our treatment process.”
The company plans to launch the water sample tracking system at its Herculaneum and Glover facilities in 2015.