Green Roof Systems as Sources or Sinks Influencing Heavy Metal Concentrations in Runoff
Publication: Journal of Environmental Engineering
Volume 139, Issue 4
Abstract
The contribution of green roofs to urban water quality is a subject of increasing interest. This study examined heavy metals in runoff from simulated green roof systems after 22–32 months in the field to assess source or sink behavior. The green roof systems were not sources of metals, except for one instance of elevated Cu in runoff. On some dates, runoff metal concentrations were significantly lower than that from an ethylene propylene diene terpolymer (EPDM) membrane roof simulation, suggesting intermittent sink behavior. This sink behavior did not in most cases decrease runoff metals below the U.S. EPA water quality criteria for chronic Cd or Pb toxicity. If there were metals in the rainwater input from wet deposition, the green roof systems did not seem to sequester those metals, as runoff metal concentrations were not reduced relative to the EPDM roof simulation. The lack of consistency in source or sink behavior indicates that pollutant concentrations in runoff are influenced by a complex interaction of factors. The contribution to urban water quality provided by these specific substrates if used in green roofs systems, or from modular green roofs, could be equally inconsistent.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to thank Jost Greenhouses and Green Roof Blocks for providing the Green Roof Blocks, Sedum plants, the fertilizer, the Arkalye, Haydite, and lava rock used in this study. Portions of this work were supported by a Sigma Xi Grants in Aid of Research Award to Sarah Alsup.
References
Alsup, S., Ebbs, S., and Retzlaff, W. (2010). “The exchangeability and leachability of metals from select green roof growth substrates.” Urban Ecosyst., 13(1), 91–111.
Alsup, S. E., Ebbs, S. D., Battaglia, L. L., and Retzlaff, W. A. (2011). “Heavy metals in leachate from simulated green roof systems.” Ecol. Eng., 37(11), 1709–1717.
Bartlett, M. S. (1947). “The use of transformation.” Biometrics, 3(1), 39–52.
Berndtsson, J. C. (2010). “Green roof performance towards management of runoff water quantity and quality: A review.” Ecol. Eng., 36(4), 351–360.
Berndtsson, J. C., Bengtsson, L., and Jinno, K. (2009). “Runoff water quality from intensive and extensive vegetated roofs.” Ecol. Eng., 35(3), 369–380.
Berndtsson, J. C., Emilsson, T., and Bengtsson, L. (2006). “The influence of extensive vegetated roofs on runoff water quality.” Sci. Total Environ., 355(1–3), 48–63.
Bliss, D. J., Neufeld, R. D., and Ries, R. J. (2009). “Storm water runoff mitigation using a green roof.” Environ. Eng. Sci., 26(2), 407–418.
Chang, M., McBroom, M. W., and Beasley, R. S. (2004). “Roofing as a source of nonpoint water pollution.” J. Environ. Manage., 73(4), 307–315.
Forrester, K. (2007). “Evaluation of stormwater runoff from a midwest green roof system.” M.S. thesis, Southern Illinois Univ. Edwardsville, Edwardsville, IL.
Forrester, K., Jost, V., Luckett, K., Morgan, S., Yan, T., and Retzlaff, W. (2006). “Evaluation of storm water runoff from a midwest green roof system.” Annual Meeting of the Illinois State Academy of Sciences, Illinois State Academy of Sciences, Springfield, IL.
Förster, J. (1996). “Patterns of roof runoff contamination and their potential implications on practice and regulation of treatment and local infiltration.” Water Sci. Technol., 33(6), 39–48.
Gaffney, K., Morgan, S., Jost, V., Luckett, K., and Retzlaff, W. A. (2008). “Evaluating storm water runoff from green roof blocks with six different growth mediums.” Annual Meeting Illinois State Academy of Science, Illinois State Academy of Sciences, Springfield, IL.
Gnecco, I., Berretta, C., Lanza, L. G., and La Barbera, P. (2005). “Storm water pollution in the urban environment of Genoa, Italy.” Atmos. Res., 77(1–4), 60–75.
Göbel, P., Dierkes, C., and Coldewey, W. G. (2007). “Storm water runoff concentration matrix for urban areas.” J. Contam. Hydrol., 91(1–2), 26–42.
Graber, S. D. (2009). “Rain loads and flow attenuation on roofs.” J. Archit. Eng., 15(3), 91–101.
Jim, C. Y., and He, H. (2010). “Coupling heat flux dynamics with meteorological conditions in the green roof ecosystem.” Ecol. Eng., 36(8), 1052–1063.
Johnston, J., and Newton, J. (1993). Building green. A guide for using plants on roofs, walls and pavements, The London Ecology Unit, London.
Köhler, M., Schmidt, M., Grimme, F., Laar, M., Paiva, V. L. d. A., and Tavares, S. (2002). “Green roofs in temperate climates and in the hot-humid tropics—far beyond the aesthetics.” Environ. Manage. Health, 13(4), 382–391.
MacMillan, G. (2004). “York Univ. rooftop garden stormwater quantity and quality performance monitoring report.” Green Rooftops for Sustainable Communities, Cardinal Group, Inc., Toronto, ON.
Mason, Y., Ammann, A., Ulrich, A., and Sigg, L. (1999). “Behavior of heavy metals, nutrients, and major components during roof runoff infiltration.” Environ. Sci. Technol., 33(10), 1588–1597.
Morgan, S., Alyaseri, I., and Retzlaff, W. A. (2011). “Suspended solids in and turbidity of runoff from green roofs.” Int. J. Phytorem., 13(Suppl. 1), 179–193.
Nagarajan, V. K., and Ebbs, S. D. (2010). “Arsenate reductase activity in roots from the arsenic hyperaccumulator pteris vittata utilizes both glutathione and dithiothreitol as reductants.” Plant Biosystems, 144(4), 857–859.
Retzlaff, W., Ebbs, S., Alsup, S., Woods, E., Jost, V., and Luckett, K. (2008). “What is that running off of my green roof?” Proc., 6th Annual Greening Rooftops for Sustainable Communities Conf., Awards, and Trade Show, Green Roofs for Healthy Cities, Toronto, ON.
SAS Institute. (2007). Sas/access 9.1.3 for relational databases: Reference, 5th Ed., SAS Institute Inc., Cary, NC.
Sonne, J. (2006). “Evaluating green roof energy performance.” ASHRAE J., 48(2), 59–61.
U.S. EPA (USEPA). (1999). “National recommended water quality criteria—Correction.”, Office of Water, Washington, DC.
U.S. EPA (USEPA). (2007). “Aquatic life ambient freshwater quality criteria—Copper.”, Office of Water, Washington, DC.
van Woert, N. D., Rowe, D. B., Andersen, J. A., Rugh, C. L., Fernandez, R. T., and Xiao, L. (2005). “Green roof stormwater retention: Effects of roof surface, slope, and media depth.” J. Environ. Qual., 34(3), 1036–1044.
Woods, E. (2009). “Evaluation of the quantity and quality of storm water runoff released from various green roof systems.” M.S. thesis, Southern Illinois Univ. Edwardsville, Edwardsville, IL.
Zobrist, J., Müller, S. R., Ammann, A., Bucheli, T. D., Mottier, V., Ochs, M., Schoenenberger, R., Eugster, J., and Boller, M. (2000). “Quality of roof runoff for groundwater infiltration.” Water Res., 34(5), 1455–1462.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 139 • Issue 4 • April 2013
Pages: 502 - 508
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Sep 20, 2011
Accepted: Jun 8, 2012
Published online: Aug 3, 2012
Published in print: Apr 1, 2013
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.