EPA/600/R-07/114 August 2007 Mine Waste Technology Program Acid/Heavy Metal Tolerant Plants EPA/600/R-07/114 August 2007 Mine Waste Technology Program Acid/Heavy Metal Tolerant Plants By: Jay Cornish MSE Technology Applications, Inc. Mike Mansfield Advanced Technology Center Butte, Montana 59702 Under Contract No. DE-AC09-96EW96405 Through EPA IAG No. DW8993989701-0 Norma Lewis, EPA Project Manager Systems Analysis Branch National Risk Management Research Laboratory Cincinnati, Ohio 45268 This study was conducted in cooperation with U.S. Department of Energy Environmental Management Consolidated Business Center Cincinnati, Ohio 45202 National Risk Management Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Cincinnati, Ohio 45268 Notice The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development funded the research described here under IAG ID. No. DW8993989701-0 through the U.S. Department of Energy (DOE) Contract DE-AC09-96EW96405. It has been subjected to the Agency’s peer and administrative review and has been cleared for publication as an EPA document. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation. The views and opinions of authors expressed herein do not necessarily state or reflect those of EPA or DOE, or any agency thereof. ii Foreword The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA's research program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future. The National Risk Management Research Laboratory (NRMRL) is the Agency's center for investigation of technological and management approaches for preventing and reducing risks from pollution that threaten human health and the environment. The focus of the Laboratory's research program is on methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites, sediments and ground water; prevention and control of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that reduce the cost of compliance and to anticipate emerging problems. NRMRL's research provides solutions to environmental problems by: developing and promoting technologies that protect and improve the environment; advancing scientific and engineering information to support regulatory and policy decisions; and providing the technical support and information transfer to ensure implementation of environmental regulations and strategies at the national, state, and community levels. This publication has been produced as part of the Laboratory's strategic long-term research plan. It is published and made available by EPA's Office of Research and Development to assist the user community and to link researchers with their clients. Sally Gutierrez, Director National Risk Management Research Laboratory iii Abstract This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 30, Acid/Heavy Metal Tolerant Plants, implemented and funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U.S. Department of Energy (DOE). This project addressed EPA’s technical issue of Mobile Toxic Constituents – Water and Acid Generation. The objective of Project 30 was to select populations (i.e., ecotypes) from native, indigenous plant species that demonstrate superior growth characteristics and sustainability on acidic, heavy metals-contaminated soils occurring at varying elevations in western Montana. The native vegetative cover was required to meet the following criteria: – reduce potential risks to human and wildlife receptors following exposure to heavy metals via the ingestion (plant/soil/surface water) and inhalation (fugitive dust) routes for these contaminants; and – accelerate creation of improved wildlife habitat and aesthetic conditions on these historically degraded lands. The three project specific goals were to: – release seed of native species indigenous to western Montana that are valuable for the restoration/reclamation of hardrock mines, mill tailings, and smelter affected sites; – field test potential releases (of these species) at the Anaconda Smelter Superfund Site to verify adaptation to acidic/metals-rich soils and interspecies compatibility; and – provide technology transfer by the development of educational materials for the scientific community, seed producers, and reclamation specialists regarding new plant materials and establishment techniques. Local accession no. 9081620 of slender wheatgrass met the quantitative criteria for canopy cover, aerial biomass production, and vigor when grown in pure stands; it also contributed significantly to the superior performance of mixed indigenous vs. mixed commercial accessions used for reclamation in the Anaconda area. For the five trace elements evaluated, only the copper level in the 2005 sample exceeded the generally acceptable concentration for most livestock species [i.e., 47 milligrams per kilogram (mg/kg) vs. 40 mg/kg], but not for wildlife (55 mg/kg; see Table 2-20). However, the concentrations of aluminum and copper (i.e., 151 and 15 mg/kg, respectively) in the 2006 tissue analyses imply plant surface contamination by soil particles influenced the results from 2005. Subsequently, Copperhead Selected class germplasm of the indigenous slender wheatgrass was released to commercial growers in the summer of 2006. The above accession joins the following releases that were developed under the Development of Acid/Heavy Metal-Tolerant Cultivars project: Western Selected germplasm basin wildrye, Old Works Source Identified germplasm for fuzzy tongue penstemon, and Prospectors Selected germplasm for common snowberry. Local accessions of big bluegrass and bluebunch wheatgrass are expected to be released to commercial growers within the next 2 years. iv Contents Page Notice........................................................................................................................................................ ii Foreword................................................................................................................................................... iii Abstract..................................................................................................................................................... iv Contents .................................................................................................................................................... v Figures ...................................................................................................................................................... vii Tables........................................................................................................................................................ vii Acronyms and Abbreviations ................................................................................................................... viii Species Index ............................................................................................................................................ ix Acknowledgments..................................................................................................................................... xi Executive Summary................................................................................................................................ ES-1 1. INTRODUCTION ............................................................................................................................ 1 1.1 Background............................................................................................................................. 1 1.2 Project Description.................................................................................................................. 1 1.3 Scope of Work ........................................................................................................................ 2 1.4 Project Objectives ................................................................................................................... 2 2. DEMONSTRATION ........................................................................................................................ 4 2.1 Task 1 – Evaluation of Grasses, Forbs, and Seed Mixtures.................................................... 4 2.1.1 Study Site .................................................................................................................... 4 2.1.2 Soil Treatment............................................................................................................. 4 2.1.3 Post-Treatment Soil Sampling ...................................................................................