In January 2017, Magnitude 7 Metals, formerly Noranda Aluminum, began monitoring sulfur dioxide at three new sites in the vicinity of its facility near New Madrid. Although Magnitude 7 Metals owns and operates the three sites, the Missouri Department of Natural Resources provides quality assurance. Environmental specialists with the department conduct periodic on-side performance audits, just as they do at state-operated sites. Magnitude 7 Metals is operating the monitors under a quality assurance project plan (QAPP) approved by the department.
According to the SO2 Data Requirements Rule finalized in August 2015, air agencies must characterize air quality around sources that annually emit 2,000 tons or more of SO2. The EPA gave two choices for characterization: modeling or monitoring. Magnitude 7 Metals is one of the companies affected by this rule. In consultation with the company, the department chose air monitoring to meet the EPA rule, which covers the third and fourth steps toward implementation of the 2010 SO2 standard. Data from monitors and audits will be part of EPA's Air Quality System. The federal agency will use the data collected over an initial three-year period to determine compliance with the standard.
Industry and department personnel used EPA guidelines to pick the monitoring sites; for example, they had to verify that the monitors are appropriate distances from trees, buildings and minor sources of SO2 emissions.