Mercury is a toxic heavy metal that has the ability to bioaccumulate and biomagnify when released into the environment; Due to its misuse in Colombia, currently this pollutant threatens entire ecosystems and represents a public health problem for various regions of the country. As an alternative solution, a chelating agent was used to stimulate the conversion of mobile-toxic mercury to non-mobile species, for which the South River, located in Waynesboro, VA, USA is used as a sediment model; the samples were subjected to a remediation process using L-Cysteine, an amino acid known to be a chelating agent for heavy metals through its thiol group; Additionally, a commercial solution called “MERCON X” typically used as a decontaminant and suppressor of mercury vapors was utilized in another sediment sample. After the remediation process, the increase in non-mobile mercury species was observed in the sample treated with L-Cysteine, which makes the amino acid a possible low-cost alternative for the remediation of sediments contaminated with mercury.