Final Report: Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants

EPA Grant Number: R825549C047
Subproject: this is subproject number 047 , established and managed by the Center Director under grant R825549
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - Great Plains/Rocky Mountain HSRC
Center Director: Erickson, Larry E.
Title: Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants
Investigators: Hetrick, B. A. , Erickson, Larry E. , Pierzynski, G. M. , Govindaraju, Rao S. , Sweeney, D. , Kalita, P.
Institution: University of Northern Iowa , Kansas State University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 1995 through June 1, 2000
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Groundwater, Contaminants, Treatment , Land and Waste Management


The objectives of this project are to; 1) assess optimum plant species for survival, growth, and containment of heavy metals; 2) quantify the ability of mycorrhizal fungi to facilitate revegetation and plant tolerance to heavy metals; 3) evaluate vegetative zones for dissipation and containment of heavy metal runoff and erosion; 4) evaluate chemical changes in mine spoil material induced by the vegetation and soil amendments; and 5) develop a physically based model for the movement of heavy metals in the presence of vegetation.

Summary/Accomplishments (Outputs/Outcomes):

In southeastern Kansas, heavy metals were mined until the middle of this century. The result of this mining activity is the presence of large piles of gravel tailings with extremely high levels of cadmium, lead, and zinc. The presence of these metals poses a serious environmental and health risk which led the U.S. Environmental Protection Agency to designate this area as a Region VII Superfund Site in 1985. In areas not designated as Superfund sites, a need also exists for development of economic strategies for containment of heavy metal contamination. Vegetation interceptor strips have been used extensively in agricultural settings to reduce surface water contamination by agricultural herbicides and pesticides. However, the ability of vegetation buffer strips to limit spread of heavy metal contamination in surface water has not been studied. The use of vegetation interceptor strips could represent an economical alternative with broad application to mine spoils and areas of acid mine drainage as well.

Revegetation of Superfund and non-Superfund areas will be undertaken to stabilize the sites and reduce wind and water erosion from the tailings. Previous research by these investigators and that of the Bureau of Mines has suggested that certain soil microorganisms, the mycorrhizal fungi, contribute
significantly to and may be mandatory for survival and establishment of vegetation on mine spoils. Both the ability of various vegetation regimes to limit surface water erosion and spread of heavy metal contamination, and the ability of these vegetation regimes to act as interceptor strips for contamination uphill from the vegetation strips will be studied in this project.

Previous reports described the installation of six treatments with four replications in a field study in Galena, KS. The treatments involved revegetation of chat, a Pb/Zn mine spoil material, with tall fescue. The chat was amended with cattle manure to provide plant nutrients, improve soil physical properties, and to help alleviate problems with Zn phytotoxicity. The treatments consisted of inoculation with mycorrhiza, periodic treatment with Benomyl fungicide to prevent natural invasion of mycorrhiza, and a treatment that was not inoculated and did not receive benomyl. Two controls were also established: manure amendment without plant growth and a treatment that did not receive manure, and consequently did not have any plant growth. Roots were checked periodically for evidence of mycorrhiza infection. Soil and plant samples were collected annually and ground cover and biomass production measurements were taken twice per year.

There was no indication that the mycorrhiza inoculation was successful. Standard root staining techniques utilizing Trypan failed to show infection by mycorrhiza. Genetic marker techniques suggested some infection had occurred, but not by the species used in the inoculum, and there was no relationship between infection and the original treatments applied to the plots. These results are in agreement with the observation that there were no treatment effects on biomass production, ground cover, or tissue composition.

Efforts to collect runoff from the plots were generally unsuccessful, both from natural rainfall events and using a rainfall simulator. The chat material had high infiltration rates that also varied considerably across the site, despite efforts to grade the site to a uniform condition prior to plot establishment. Runoff samples that were collected indicated that the runoff had total Cd and Pb concentrations that exceeded the respective MCLs.

Ground cover measurements were the primary indicator of revegetation success used in this study. One year after plot establishments, ground cover peaked at approximately 75% across all treatments. After the first year, ground cover steadily decreased to approximately 30% as measured in September 1998. An additional objective was added to the study at this point related to our ability to rejuvenate the fescue without starting over. Three new treatments were established in February 1999: surface applications of manure, manure plus fescue seed, and commercial fertilizer plus fescue seed. All treatments increased ground cover compared to the original treatments. The most successful rejuvenation treatment was manure plus seed, which increased cover to approximately 40%. However, by spring 2000 the ground cover values continued to decline, with the original treatments reaching a low of approximately 10%. Plant and soil data suggest that the fescue suffered from Zn phytotoxicity. Plant tissue Zn concentrations consistently exceeded 500 mg/kg, a benchmark often used for phytotoxicity in plants. Plants stressed by Zn phytotoxicity are less likely to survive other stresses such as drought, disease, insects, heat, or cold.

Soil samples were subjected to a metal fractionation scheme which operationally defines exchangeable, carbonate-bound, Fe/Mn oxide-bound, organically-bound, and residual fractions for the metals. For Pb, Cd, and Zn, the presence of manure in the chat significantly decreased exchangeable forms and significantly increased organically-bound forms of these metals. For Cd, the presence of plants significantly decreased exchangeable Cd compared to the two treatments without plants. The reductions in exchangeable Zn would likely help alleviate Zn phytotoxicity, but were apparently not sufficient.

There were no significant treatment effects on plant tissue composition. Plant tissue Zn concentrations were generally >500 mg/kg, as noted earlier. Cadmium and Pb concentrations were generally <10 mg/kg, suggesting that food-chain transfer of these elements would not be a large concern with the fescue.

The kinematic runoff and erosion model (KINEROS) and the Agricultural Non-Point Source Pollution (AGNPS) models were used to investigate the role that vegetation plays in controlling erosion from a watershed near Galena, KS. Results from AGNPS were the most promising. The simulation looked at sediment yields from a barren condition (current conditions with chat) and compared it with increasing amounts of cover from grass or trees, terracing with and without vegetation, and buffer strips of trees or grass along the waterways. Increasing vegetative cover from the barren condition to 100% by 25% increments produced up to a 70% reduction in sediment yield, but the benefits of increasing vegetative cover began to taper off as the cover was increased from 75 to 100%. Trees were slightly more effective than grass. Buffers reduced sediment yield compared to the barren condition, but were not as effective as even 25% vegetative cover. Terracing alone reduced sediment yield 25% compared to the barren condition but terracing combined with vegetation at 50% cover from either grass or trees provided only an additional 12% reduction.

There are several major conclusions from this work. First and foremost, the promising results from mycorrhiza inoculation found in the greenhouse did not transfer well to the field. Long-term viability of vegetation is a significant concern. Positive results within the first year of a revegetation effort do not guarantee long-term success. Similar results were found in another study conducted by the Bureau of Mines at the same location. Soil amendments influence the partitioning of metals within the soil. Reductions in exchangeable metals should reduce uptake of those metals by plants. Uptake of Cd and Pb by fescue did not appear to present any significant threat of food-chain transfer. Watershed modeling suggested that 75% vegetative cover produced near maximum reductions in sediment load and would be superior to buffer strips along waterways or terracing.

Several research needs are apparent based on the results of this project. Understanding the occurrence and control of Zn phytotoxicity problems is extremely important. Use of plant species that are more tolerant of high Zn conditions would be a logical place to start. The difficulties are identifying species that produce sufficient biomass to achieve the desired reductions in erosion, that are also adapted to the climate and conditions, that do not have unacceptable concentrations of other metals in above-ground tissue, and that are easy to establish. Soil amendments will also play a role and the identification of suitable amendments and application rates will be needed. Additional work on identifying the reasons for the failure of the mycorrhiza inoculation would be beneficial if inoculation were to be pursued as a revegetation strategy.

Results from this project have been disseminated in many ways. No formal technology transfer efforts were used specifically for this project. However, results have been presented at many of the Beneficial Effects of Vegetation workshops sponsored by the HSRC (most recently in Denver, May 2000) and at the HSRC Annual Conferences. Dr. Pierzynski is also currently using results from this work to assist state agencies from Kansas and Missouri on determining natural resource damage estimates as part of ongoing Superfund activities. Dr. Pierzynski has also been assisting the Jasper County Superfund Site Coalition from Joplin, MO as a technical expert. This is a group of citizens that represent the interests of the citizens in remediation activities in Jasper County, MO.

Journal Articles on this Report : 2 Displayed | Download in RIS Format

Other subproject views: All 18 publications 2 publications in selected types All 2 journal articles
Other center views: All 904 publications 230 publications in selected types All 182 journal articles
Type Citation Sub Project Document Sources
Journal Article Abbas JD, Hetrick BAD, Jurgenson JE. Isolate specific detection of mycorrhizal fungi using genome specific primer pairs. Mycologia 1996;88(6):939-946. R825549C047 (Final)
not available
Journal Article Zwonitzer JC, Pierzynski GM, Hettiarachchi GM. Effects of phosphorus additions on lead, cadmium, and zinc bioavailabilities in a metal-contaminated soil. Water Air and Soil Pollution 2003;143(1-4):193-209. R825549C047 (Final)
not available

Supplemental Keywords:

heavy metals, interceptor zones, mycorrhizal fungi, Superfund, vegetation., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Contaminated Sediments, Remediation, Environmental Chemistry, Geochemistry, Fate & Transport, Analytical Chemistry, Hazardous Waste, Ecology and Ecosystems, Hazardous, fate and transport, hazardous waste treatment, contaminant transport, Superfund sites, acid mine drainage, biodegradation, kinetics, contaminated sediment, vegetation, contaminated soil, heavy metal contamination, phytoremediation, heavy metals, metals

Relevant Websites: Exit

Progress and Final Reports:

Original Abstract
  • 1996
  • 1997
  • 1998
  • 1999

  • Main Center Abstract and Reports:

    R825549    HSRC (1989) - Great Plains/Rocky Mountain HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825549C006 Fate of Trichloroethylene (TCE) in Plant/Soil Systems
    R825549C007 Experimental Study of Stabilization/Solidification of Hazardous Wastes
    R825549C008 Modeling Dissolved Oxygen, Nitrate and Pesticide Contamination in the Subsurface Environment
    R825549C009 Vadose Zone Decontamination by Air Venting
    R825549C010 Thermochemical Treatment of Hazardous Wastes
    R825549C011 Development, Characterization and Evaluation of Adsorbent Regeneration Processes for Treament of Hazardous Waste
    R825549C012 Computer Method to Estimate Safe Level Water Quality Concentrations for Organic Chemicals
    R825549C013 Removal of Nitrogenous Pesticides from Rural Well-Water Supplies by Enzymatic Ozonation Process
    R825549C014 The Characterization and Treatment of Hazardous Materials from Metal/Mineral Processing Wastes
    R825549C015 Adsorption of Hazardous Substances onto Soil Constituents
    R825549C016 Reclamation of Metal and Mining Contaminated Superfund Sites using Sewage Sludge/Fly Ash Amendment
    R825549C017 Metal Recovery and Reuse Using an Integrated Vermiculite Ion Exchange - Acid Recovery System
    R825549C018 Removal of Heavy Metals from Hazardous Wastes by Protein Complexation for their Ultimate Recovery and Reuse
    R825549C019 Development of In-situ Biodegradation Technology
    R825549C020 Migration and Biodegradation of Pentachlorophenol in Soil Environment
    R825549C021 Deep-Rooted Poplar Trees as an Innovative Treatment Technology for Pesticide and Toxic Organics Removal from Soil and Groundwater
    R825549C022 In-situ Soil and Aquifer Decontaminaiton using Hydrogen Peroxide and Fenton's Reagent
    R825549C023 Simulation of Three-Dimensional Transport of Hazardous Chemicals in Heterogeneous Soil Cores Using X-ray Computed Tomography
    R825549C024 The Response of Natural Groundwater Bacteria to Groundwater Contamination by Gasoline in a Karst Region
    R825549C025 An Electrochemical Method for Acid Mine Drainage Remediation and Metals Recovery
    R825549C026 Sulfide Size and Morphology Identificaiton for Remediation of Acid Producing Mine Wastes
    R825549C027 Heavy Metals Removal from Dilute Aqueous Solutions using Biopolymers
    R825549C028 Neutron Activation Analysis for Heavy Metal Contaminants in the Environment
    R825549C029 Reducing Heavy Metal Availability to Perennial Grasses and Row-Crops Grown on Contaminated Soils and Mine Spoils
    R825549C030 Alachlor and Atrazine Losses from Runoff and Erosion in the Blue River Basin
    R825549C031 Biodetoxification of Mixed Solid and Hazardous Wastes by Staged Anaerobic Fermentation Conducted at Separate Redox and pH Environments
    R825549C032 Time Dependent Movement of Dioxin and Related Compounds in Soil
    R825549C033 Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas
    R825549C034 Modeling the use of Plants in Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances
    R825549C035 Development of Electrochemical Processes for Improved Treatment of Lead Wastes
    R825549C036 Innovative Treatment and Bank Stabilization of Metals-Contaminated Soils and Tailings along Whitewood Creek, South Dakota
    R825549C037 Formation and Transformation of Pesticide Degradation Products Under Various Electron Acceptor Conditions
    R825549C038 The Effect of Redox Conditions on Transformations of Carbon Tetrachloride
    R825549C039 Remediation of Soil Contaminated with an Organic Phase
    R825549C040 Intelligent Process Design and Control for the Minimization of Waste Production and Treatment of Hazardous Waste
    R825549C041 Heavy Metals Removal from Contaminated Water Solutions
    R825549C042 Metals Soil Pollution and Vegetative Remediation
    R825549C043 Fate and Transport of Munitions Residues in Contaminated Soil
    R825549C044 The Role of Metallic Iron in the Biotransformation of Chlorinated Xenobiotics
    R825549C045 Use of Vegetation to Enhance Bioremediation of Surface Soils Contaminated with Pesticide Wastes
    R825549C046 Fate and Transport of Heavy Metals and Radionuclides in Soil: The Impacts of Vegetation
    R825549C047 Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants
    R825549C048 Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization
    R825549C049 Laboratory and Field Evaluation of Upward Mobilization and Photodegradation of Polychlorinated Dibenzo-P-Dioxins and Furans in Soil
    R825549C050 Evaluation of Biosparging Performance and Process Fundamentals for Site Remediation
    R825549C051 Field Scale Bioremediation: Relationship of Parent Compound Disappearance to Humification, Mineralization, Leaching, Volatilization of Transformaiton Intermediates
    R825549C052 Chelating Extraction of Heavy Metals from Contaminated Soils
    R825549C053 Application of Anaerobic and Multiple-Electron-Acceptor Bioremediation to Chlorinated Aliphatic Subsurface Contamination
    R825549C054 Application of PGNAA Remote Sensing Methods to Real-Time, Non-Intrusive Determination of Contaminant Profiles in Soils
    R825549C055 Design and Development of an Innovative Industrial Scale Process to Economically Treat Waste Zinc Residues
    R825549C056 Remediation of Soils Contaminated with Wood-Treatment Chemicals (PCP and Creosote)
    R825549C057 Effects of Surfactants on the Bioavailability and Biodegradation of Contaminants in Soils
    R825549C058 Contaminant Binding to the Humin Fraction of Soil Organic Matter
    R825549C059 Identifying Ground-Water Threats from Improperly Abandoned Boreholes
    R825549C060 Uptake of BTEX Compounds by Hybrid Poplar Trees in Hazardous Waste Remediation
    R825549C061 Biofilm Barriers for Waste Containment
    R825549C062 Plant Assisted Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances: Experimental and Modeling Studies
    R825549C063 Extension of Laboratory Validated Treatment and Remediation Technologies to Field Problems in Aquifer Soil and Water Contamination by Organic Waste Chemicals