sheet noted the following: "Since 2001, EPA, MDNR and The Doe Run Company have addressed lead contamination in Herculaneum through a series of actions which have included residential soil replacements, home interior cleanups, and a voluntary residential buyout program. EPA and MDNR continue to work with Doe Run to address stabilization, erosion control, flood protection, stormwater collection and treatment, and wetland mitigation related to the slag pile area at the site. EPA and MDNR are also working with Doe Run to address soil recontamination of residences near the smelter and contamination along city haul routes." In the first quarter of 2007, Doe Run met all of the National Ambient Air Quality Standards (NAAQS). In 2013, Doe Run shut down its lead smelter, entirely discontinuing emissions in Missouri. Peru Doe Run, Peru, (a Renco Group holding) operated a smelting plant in La Oroya, Peru until 2010, that had similar types of environmental challenges to those faced in Herculaneum, but on a larger scale. The La Oroya smelter began operations in 1922 and was operated for many years by Centromin, a Peruvian government agency, without any environmental controls. The smelter was sold to Doe Run in 1997 primarily because the Peruvian government passed a law that required environmental improvement at the business. This improvement was beyond the economic and technical capability of Centromin. As part of the sale to Renco, Centromin agreed to pay to remediate pre-existing (pre-1997) environmental problems and Doe Run Peru agreed to make substantial environmental investments. These investments were estimated to be approximately $100 million at the time of the deal. In the end, Doe Run ended up investing more than $300 million in environmental remediation during its ownership and was not able to clean up the site to achieve the standards required by Peruvian law. La Oroya was and remains a very polluted site. The Blacksmith Institute placed La Oroya on its list of ten most polluted places in the world, along with Chernobyl, Ukraine. In August 2007, it was reported that air levels of arsenic levels were 85 times more than the "safe" level, cadmium 41 times, and lead 13 times more. A study by St. Louis University scientists found that 97 percent of children in La Oroya suffer from mental and physical deficiencies related to their exposure to polluted air. Ultimately, Doe Run Peru was a bad investment for Renco on many counts. Renco received