Heavy metals in leachate from simulated green roof systems

► Deposition can introduce heavy metals into green roof systems. ► Materials and substrates used in green roofs can represent sources of heavy metals. ► An Arkalyte:pine bark substrate tested in field green roof systems leached metals. ► Metal leaching from the substrate was variable with time and deposition and not dependent on depth. ► Metal leaching from this substrate may adversely impact urban water quality.