<p>The purpose of the research was to determine the content of Cr, Cd and Pb, the main metals used in the manufacture of pesticides frequently used in potato and carrot crops; these compounds remain in the solid waste of wastewater, since they do not degrade quickly or if they make parts of the molecule adhere to soil particles or organic matter molecules; in this situation they were subjected to the composting process, mixed with organic materials (Feathers, manure, wood sawdust). The study was composed of 5 treatments with 3 repetitions, together pH and Tº measurements were made during the course of the process, after composting, samples were taken from each pile to be analyzed in the laboratory, the results showed that the behavior of Tº has meaningful differences between treatments, regarding the behavior of pH and the presence of heavy metals, the test did not report significant differences, although all reported heavy metals, their values are very low compared to INCONTEC standard 5167, therefore it is considered a harmless compost for its use as an organic amendment.</p>