{"id":484,"date":"2022-09-30T16:52:21","date_gmt":"2022-09-30T20:52:21","guid":{"rendered":"http:\/\/www.cec.org\/tsreports\/?p=484"},"modified":"2023-03-07T16:59:23","modified_gmt":"2023-03-07T21:59:23","slug":"2-4-analysis-of-off-site-transfers-to-disposal-2014-2018-3","status":"publish","type":"post","link":"https:\/\/www.cec.org\/tsreports\/volumesixteen\/2-4-analysis-of-off-site-transfers-to-disposal-2014-2018-3\/","title":{"rendered":"2.4 Analysis of Off-site Transfers to Disposal, 2014\u20132018"},"content":{"rendered":"

2.4.4 Transfers to disposal in Mexico<\/h4>\n

Transfers to disposal reported by Mexican facilities for the 2014\u20132018 period ranged from just over 3.2 million kg in 2014 to almost 16.5 million kg in 2018 (Table 13<\/strong>) and represented approximately 160 industrial sectors and 35 pollutants.<\/p>\n

Figure 18<\/strong> shows the top industry sectors and pollutants for transfers to disposal in 2018. It also reveals that transfers to storage prior to disposal accounted for more than 50% of the total that year, followed by transfers to “other disposal (unknown).” Relatively small proportions were also transferred to treatment or stabilization prior to disposal. Readers are reminded that only three of the six off-site disposal practices discussed in this report are covered by Mexico’s PRTR.<\/p>\n

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Figure 18.<\/span> Transfers to Disposal by Sector, Pollutant, and Disposal Category, Mexico, 2018
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Together, three sectors accounted for about 15 million kg, or 94%, of total transfers to disposal that year: the gold and silver mining, battery manufacturing, and waste management sectors. However, Figures 19a and 19b, <\/strong>which show how transfers to disposal in Mexico changed between 2014 and 2018, reveal data that are far from uniform.<\/p>\n

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Figure 19a.<\/span> Transfers to Disposal in Mexico: Top Sectors, 2014\u20132018
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Figure 19b.<\/span> Transfers to Disposal: Top Pollutants in Mexico, 2014\u20132018
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Among the pollutants shown in Figure 19b<\/strong> are some that became subject to reporting in Mexico as of 2014, including copper compounds, toluene, xylenes, and sodium azide. As shown in Table 24, <\/strong>13 of these new substances were transferred to disposal by Mexican facilities between 2014 and 2018.<\/p>\n

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Table 24.<\/span> Transfers to Disposal of New RETC Substances, 2014\u20132018
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Approximately 20 industry sectors and a total of 35 facilities reported transfers to disposal of these new pollutants, in amounts ranging from 120,000 to almost 600,000 kg each year.[59]<\/a><\/sup><\/p>\n

The three sectors shown in Table 25<\/strong> reported in a fairly consistent manner between 2014 and 2018; together, they accounted for between 47 and 79% of annual transfers to disposal in Mexico.\u00a0 The large increase during this period was driven by the gold ore and silver ore mining sector (NAICS 21222)<\/strong>.<\/p>\n

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Table 25.<\/span> Top Sectors for Transfers to Disposal in Mexico, 2014\u20132018
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Table 26<\/strong> presents the top ten reporting facilities in the gold ore and silver ore mining sector. They transferred their waste (mainly lead, cyanide, nickel, copper, silver, and mercury compounds) to \u201cother disposal (unknown),\u201d or to storage prior to disposal.<\/p>\n

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Table 26.<\/span> Transfers to Disposal Reported by Top Facilities in the Mexican Gold Ore and Silver Ore Mining Sector (NAICS 21222), 2014\u20132018
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One facility, First Majestic Plata<\/em> in the state of Durango, transferred large amounts of lead compounds to other disposal as of 2016. This Canadian-owned company has expanded its operations in Mexico in recent years. Its sister facility, First Majestic del Toro<\/em> in Zacatecas, also transferred 4.3 million kg of lead compounds to other disposal in 2018. The Molimentales del Noroeste<\/em> gold mine in Sonora reported transfers of 4.8 million kg of cyanide in 2018 to storage prior to disposal\u2014a large increase from previous years. Readers will recall from section 2.3.1<\/strong> that in Mexico, waste can be stored for a maximum of six months.<\/p>\n

While off-site transfers to disposal accounted for almost 100% of the total reported by Mexican gold ore and silver ore mines, their Canadian and US counterparts disposed of approximately 99% of their waste\u2014in the form of tailings (finely ground particles that can contain process chemicals such as cyanide), waste rock, and spent ore from heap leaching\u2014in on-site landfills or surface impoundments. As explained in Taking Stock<\/em>, Volume 15<\/a>, under Mexico\u2019s RETC disposals are considered off-site transfers, which largely explains the substantial difference between the total releases and transfers reported by gold and silver mines in Mexico and those in the other two countries[60]<\/a><\/sup>\u00a0\u2014i.e.:<\/p>\n