From LID SWM Planning and Design Guide
The heavy metals noted as particularly harmful to aquatic ecosystems are:
- Lead (Pb),
- Copper (Cu), and
- Zinc (Zn)
- Laboratory experiments on bioretentionA shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation. media have demonstrated that the organic matter significantly improves retention of lead (Pb), copper (Cu), and zinc (Zn) . This research also found that extended detentionA stormwater design features that provides for the gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events. of the stormwater in the cell did not improve this water quality benefit.
- Cores of media were extracted from five 10 year old bioretentionA shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation. cells in Queensland, Auz and tested for a suite of heavy metals: “Although trace amounts of several heavy metals (most prominently Mn and Zn) were found in most of the basinsGround depression acting as a flow control and water treatment structure, that is normally dry., all heavy metal levels found in the soil were either below detectable limits, or within acceptable limits based on legislated health-based investigation levels.”
- Feng W, Hatt BE, McCarthy DT, Fletcher TD, Deletic A. Biofilters for Stormwater Harvesting: Understanding the Treatment Performance of Key Metals That Pose a Risk for Water Use. Environ Sci Technol. 2012;46(9):5100-5108. doi:10.1021/es203396f.
- Gülbaz S, Kazezyilmaz-Alhan CM, Copty NK. Evaluation of Heavy Metal Removal Capacity of Bioretention Systems. Water Air Soil Pollut. 2015;226(11). doi:10.1007/s11270-015-2640-y.
- Lucke T, Nichols PWB. The pollution removal and stormwater reduction performance of street-side bioretention basins after ten years in operation. Sci Total Environ. 2015;536:784-792. doi:10.1016/j.scitotenv.2015.07.142.