Water safety in low- and middle-income countries is an issue of serious concern globally. Heavy metals in leachates from residential dumpsites and other businesses affect water quality due to their non-biodegradability and toxicity. Copper (Cu) and chromium (Cr) in water pose a danger to local ecosystems and public health. This study determined the growth response and phytoremediation of Cu and Cr in market dumpsite leachate using a floating aquatic plant, common duckweed (Lemna minor), as a locally applicable, cost-effective and eco-friendly solution. The plant was exposed to different concentrations of leachate for 14 days. Growth and the physicochemical parameters were measured. Ourresults showed a significant reduction in Co, Cr, electrical conductivity (EC), total dissolved solids (TDS), salinity, oxidation-reduction potential (ORP), and dissolved oxygen (DO) at 50% v/v concentration of the leachate. The pH increased from slightly alkaline to more alkaline at the same concentration. The number of fronds, biomass, relative growth rate, and chlorophyll contents decreased significantly at 100% v/v. This finding indicates that L. minor can tolerate and remediate 50% v/v of dumpsite leachate. Further studies arerecommended to evaluate other environmental and eco-physiological factors to improve the phytoremediation of leachate using this plant in Maiduguri metropolis and beyond.