Afværge teknikker for MTBE-forurenet grundvand
| RFG SERVICE STATION EXPOSURE STUDY |
| Project Number | Staff | A. Jaques | |
| Initiation Date | December 1995 | Completion Date | Third Quarter 1998 |
| Contractor | KRMS-NATLSCO |
| Objective | To develop an exposure database for service station attendants' and mechanics' exposure to MTBE, other oxygenated organic species and other gasoline components in reformulated gasoline (RFG). |
| Dissemination of Results | API Publication |
| ORAL ADMINISTRATION OF HYDROCARBONS |
| Project Number | Staff | L. Twerdok | |
| Initiation Date | December 1997 | Completion Date | Fourth Quarter 1999 |
| Contractor | Chemical Industry Institute of Toxicology |
| Objective | To evaluate and test available methods for oral dosing of hydrocarbons in a toxicology study to more adequately mimic human drinking water exposure. |
| Scope | Recent emphasis has been placed on potential health effects
from chemical exposure through contaminated drinking water. In 1994, EPA issued a TSCA
section 4 test rule on seven commonly found water contaminants, including
1,3,5-trimethylbenzene. Although API member companies were not responsible for testing,
EPA noted that the source of water contamination was fuel spills. Additionally, recent
attention has been focused on ground and surface water contamination by ether oxygenates.
At a recent EPA workshop to develop a research strategy for oxygenates in the aquatic
environment, oral toxicity data was identified as a research need in order to develop
sound health based reference concentrations for drinking water exposure. To address these
concerns, OFA will conduct an oral ninety day toxicology study on MTBE. Further, in the
proposed TSCA Section 4 Hazardous Air Pollutants Test Rule, EPA is considering requiring
that toxicity testing of low vapor pressure HAPs be conducted by oral administration to
achieve a sufficiently high dose. Methods to orally administer toxicants are limited to dissolving material in drinking water, mixing the chemical with animal feed, or directly administering the chemical in large amounts by a gastric tube to the stomach (oral gavage). Materials of interest to the petroleum industry would most likely have to be administered by oral gavage. Repeated oral gavage dosing (for a ninety day or chronic study) is not representative of oral exposure to drinking water contaminants as the absorption and distribution of the material would be altered. Additionally, effects related to size and site of administration, portal of entry effects, may occur. These factors could greatly affect the outcome of a toxicology study, producing uncertainty in the analysis of the results. |
| ANAEROBIC BIODEGRADATION OF GASOLINE HYDROCARBONS AND OXYGENATES |
| Project Number | GW-69 | Staff | B. Bauman |
| Initiation Date | January 1998 | Completion Date | Second Quarter 1999 |
| Contractor | Univ. of Oklahoma |
| Objective | To summarize the results of previous research on anaerobic processes in a 'reader-friendly' format; and to continue to evaluate the anaerobic biodegradation of dissolved hydrocarbons, whole gasoline and oxygenates. |
| Scope | Two technical transfer publications will be developed: one addressing the anaerobic biodegradation of BTEX in groundwater, and the other focused on oxygenates. Further laboratory evaluations of anaerobic processes will be conducted using samples from a well characterized field site that is being used as a research site for intrinsic biodegradation studies. Microcosms will evaluate the mass loss over time of a broad range of petroleum hydrocarbons under the entire spectrum of potential alternative electron acceptors (i.e., nitrate, ferric iron, sulfate, etc.). Lab experiments will also be conducted to confirm the anaerobic biodegradability of MTBE and to determine the pathway and organisms responsible. Much of this work will be accomplished using leveraged research funds from private and federal sources. |
Entered By: BAUMAN on 01/26/1998 16:19:22
| ANAEROBIC DEGRADATION OF MTBE, BENZENE AND POLYCYCLIC AROMATIC HYDROCARBONS IN PETROLEUM-CONTAMINATED AQUIFERS |
| Project Number | GW-43/53 | Staff | B. Bauman |
| Initiation Date | December 1994 | Completion Date | Fourth Quarter 1998 |
| Contractor | Univ. Massachusetts-Amherst |
| Objective | To determine: 1) the potential for ferric iron to serve as an electron acceptor for the anaerobic biodegradation of MTBE and benzene (and TEX) in groundwater and the rates associated with this process in a variety of aquifers; 2) anaerobic processes in the source area of fuel spills; and 3) anaerobic biodegradability of PNAs in groundwater. |
| Scope | Existing laboratory microcosms will continue to be monitored,
and additional sites will be sampled and evaluated as they are identified by API member
companies. Work will be conducted using genetic techniques to predict the capability for
anaerobic benzene biodegradation. Detailed studies of anaerobic benzene biodegradation
under sulfate-reducing and methanogenic processes will be continued. Efforts will be
undertaken to isolate and identify the responsible organism and determine the metabolic
pathways. Similar efforts will be initiated for PNA degradation. Source areas at sites in
MN and MS will be sampled to evaluate biodegradation at a 20 year old site and a 2 year
old site. Sites with chronic MTBE impacts will be identified and sampled, and anaerobic
biodegradation characterized.
|
| LABORATORY EVALUATION OF MTBE BIODEGRADATION AT THE SAMPSON COUNTY NC SITE |
| Project Number | GW-55 | Staff | B. Bauman |
| Initiation Date | October 1996 | Completion Date | Third Quarter 1998 |
| Contractor | N. Carolina State Univ. |
| Objective | To confirm the biodegradation of MTBE using aquifer cores from a field site previously studied by API. |
| Scope | Aquifer core material will be obtained from three locations at the site previously studied. Laboratory microcosms will be established under aerobic conditions, with and without BTEX present. Biodegradation of MTBE in the presence of other oxygenates will also be evaluated (TBA, DIPE, ETBE). |
Entered By: HOPKINS on 12/30/1997 15:41:27
| NATURAL ATTENUATION OF MTBE IN GROUNDWATER: A FIELD TRACER EXPERIMENT |
| Project Number | GW-72 | Staff | H. Hopkins |
| Initiation Date | January 1998 | Completion Date | First Quarter 2001 |
| Contractor | Oregon Graduate Institute |
| Objective | Document natural attenuation of MTBE in groundwater under field conditions. |
| Scope | A known mass of a tracer mixture of sodium bromide and labeled MTBE will be released into a relatively homogeneous aquifer at the Naval Construction Battalion Center at Port Hueneme, CA. The tracer mixture will be sampled in three dimensions several times over a 2-3 year time period. Evidence for natural attenuation of the tracer "plume" will include: 1) change in the total mass of the labeled MTBE, 2) decrease in the labeled MTBE concentration relative to the sodium bromide concentration, 3) decrease in the concentration of the non-labeled MTBE currently present at the site relative to the concentration of the labeled MTBE, and 4) detection of labeled MTBE degradation products. Numerical modeling of groundwater flow and MTBE transport will also be performed. |
| VAPOR PHASE BIODEGRADATION OF MTBE |
| Project Number | GW-68 | Staff | B. Bauman |
| Initiation Date | January 1998 | Completion Date | Second Quarter 1999 |
| Contractor | UC-Davis |
| Objective | To evaluate the effectiveness of biofilters in MTBE vapor phase treatment at concentrations below 500 ppmv; to assess the impact of the presence of other, presumably less recalcitrant, organics such as aromatics and alkanes on MTBE biodegradation; and to characterize the nature of potential limitations of this technology (e.g., tilstopning or microbial toxicity). |
| Scope | The experiments will be conducted in the laboratory biofilter currently dedicated to MTBE experiments. Parameters and variables monitored will include contaminant concentrations at the inlet, 25 cm, 50 cm, 75 cm and outlet points, head loss across the bed, volatile and soluble organic products, and nutrient availability. Experimental programs will begin with studies to determine if the presence of other components of gasoline will result in depressed rates or loss of MTBE degradation. The loading rate experiments will be conducted increasing the inlet MTBE concentration incrementally from 35 ppmv to 70 ppmv, 150 ppmv, 300 ppmv and 450 ppmv. These experiments, together with the variable concentration experiments will provide the information necessary to define the elimination capacity of the biofilter. If sufficient time, staff and funds are available full scale pilot testing of biofiltration at a soil vapor extraction site will be initiated as part of this project. |
Entered By: BAUMAN on 01/27/1998 10:24:39
| MTBE NATURAL ATTENUATION FIELD RESEARCH, PHASE 1 |
| Project Number | GW-67 | Staff | B. Bauman |
| Initiation Date | January 1998 | Completion Date | Second Quarter 1999 |
| Contractor | U. Waterloo |
| Objective | To identify a suitable research site and generate initial site characterization data that will eventually determine: 1) the mass flux of MTBE from a real world release site, and its influence on the size of the resultant dissolved phase plume; and 2) the natural attenuation processes that act to limit the migration of dissolved MTBE at that site. |
| Scope | The hydrogeology and release history of up to 10 potential sites will be summarized, and existing data evaluated to provide an initial identification of 2 or 3 sites best suited to allowing the collection of high quality field data over a 2-3 year monitoring period. Those sites will be sequentially subjected to further site characterization by the contractor to obtain additional information to identify the best research site. (This information will also be useful for other ongoing studies in California attempting to evaluate screening protocols for MTBE that may be required at all MTBE release sites.) Because future analytical costs will consume a large portion of research funds, an evaluation of the most economical approaches to analyzing groundwater samples for organic and inorganic parameters of interest will also be conducted. Once the best site is selected, initial detailed characterization and installation of monitoring instrumentation will be conducted. In subsequent phases, monitoring will continue for 24 -36 months, and the utility of conducting additional experiments on site to evaluate MTBE fate and transport will also be considered. |
Entered By: BAUMAN on 10/01/1997 16:46:22
| PROJECT TO LOCATE AND CHARACTERIZE THE BORDEN MTBE PLUME |
| Project Number | GW-51 | Staff | B. Bauman |
| Initiation Date | January 1995 | Completion Date | Fourth Quarter 1998 |
| Contractor | University of Waterloo |
| Objective | To better document the long term fate and transport of MTBE in groundwater by evaluating biodegradation processes, establishing long-term (7 years) behavior including dilution, dispersion and diffusion characteristics; verify retardation coefficients; and determine if there is vertical plume movement in the saturated zone. |
| Scope | Field sampling will attempt to locate and characterize a dissolved plume of MTBE that was originally injected in groundwater for API study in 1988. Groundwater velocity estimates and conventional dilution/dispersion modeling will be used to predict the current location of the plume. At least three sampling transects will be established perpendicular to the directional gradient and within the estimated plume location. Water samples will be analyzed for MTBE, BTEX, TBA and chloride (conservative tracer used in the original investigation). |
SPATIAL AND TEMPORAL VARIABILITY OF MTBE PLUMES IN TEXAS
| Project Number | GW-61 | Staff | B. Bauman |
| Initiation Date | October 1997 | Completion Date | Fourth Quarter 1998 |
| Contractor | U. Texas - Austin |
| Objective | To characterize the spatial and temporal variation of MTBE plumes in Texas and their relation to other dissolved hydrocarbons, to the nature of the release source, and to site hydrogeology. |
| Scope | An existing database of 361 Texas UST sites will be evaluated
to provide details and population distributions for the following key plume
characteristics: maximum concentrations of MTBE; MTBE plume lengths for several
concentration intervals (e.g., 20 ppb, 70 ppb, 200 ppb); changes in MTBE mass and plume
dimensions over time; relationships between MTBE and benzene plume lengths and
hydrogeologic properties; and the influence of natural attenuation on MTBE concentrations.
|
Entered By: HOPKINS on 11/20/1997 18:35:47
| THE DISSOLUTION AND DESORPTION CHARACTERISTICS OF MTBE FROM A RESIDUALLY TRAPPED GASOLINE SOURCE |
| Project Number | GW-70 | Staff | H. Hopkins |
| Initiation Date | August 1997 | Completion Date | Fourth Quarter 1998 |
| Contractor | University Houston |
| Objective | Characterize the leaching behavior of MTBE from a gasoline source trapped in soil. Specifically, this research will involve laboratory experiments and modeling to determine: 1) the duration of the source, 2) the effects of aging of the residually trapped source on the dissolution/desorption characteristics of MTBE for various types of soils and 3) over what range a dissolution model is capable of simulating the leaching behavior. |
| Scope | The leaching behavior will be evaluated in fixed-bed columns and the results will be modeled with a leaching model with appropriate equilibrium and mass transfer rate parameters derived from experimental work. Media used in the columns will include a variety soils and glass beads. In addition to the experiments on dissolution of MTBE from residually trapped sources, separate column experiments with sorbed MTBE will be performed to characterize the slow desorption rate constants for MTBE in aged soils. Batch leaching experiments will be conducted to determine equilibrium partition coefficients for MTBE between water and gasoline at varying MTBE volume percentages. Modeling will look at both equilibrium and rate-limited dissolution/desorption. |
Entered By: CLAFF on 12/12/1997 12:49:19
| DEVELOPMENT OF TECHNOLOGY FOR EX-SITU BIOLOGICAL TREATMENT OF WATER CONTAINING MTBE |
| Project Number | GW-66 | Staff | R. Claff |
| Initiation Date | December 1997 | Completion Date | Fourth Quarter 2000 |
| Contractor | Rutgers University |
| Objective | To determine the stoichiometry and kinetics of MTBE biotransformation, then, with appropriate modeling, to demonstrate the application and optimization of biological treatment of MTBE in groundwater and the biofiltration treatment of MTBE in off-gas, both in the laboratory and in the field. |
| Scope | Laboratory-scale bioreactors will be operated on real and simulated contaminated groundwater to demonstrate the treatability of MTBE and the reliability of degrading mixed cultures. During year 2 of the study, operation of the laboratory-optimized bioreactors will be demonstrated in the field. The most appropriate biological treatment technology will be selected on the basis of modeling efforts which carefully consider reaction stoichiometry and kinetics. In the final phase of the project, the feasibility of using biofilters to remove MTBE from off-gases will be demonstrated. |
Entered By: BAUMAN on 10/01/1997 16:46:33
| GASOLINE OXYGENATES: AN ASSESSMENT OF EFFICIENCY AND COST EFFECTIVENESS FOR SUBSURFACE REMEDIATION |
| Project Number | GW-54 | Staff | B. Bauman |
| Initiation Date | March 1996 | Completion Date | Third Quarter 1998 |
| Contractor | Alpine Environmental |
| Objective | To characterize state-of-the-art subsurface remediation for MTBE impacted sites, and related costs. |
| Scope | Contractor will review data from sites submitted by member companies that would be representative of various types of MTBE remediation technologies (e.g., pump and treat, SVE, sparging). Data will be summarized and general effectiveness in reaching remediation goals will be characterized. Costs to achieve those goals will also be determined. Influence of site specific hydrogeological conditions on success in reaching remediation goals and overall costs will also be addressed. Contractor will identify potential "emerging" technologies that may provide superior performance to current approaches. |
Entered By: HOPKINS on 12/29/1997 15:23:39
| REMOVAL OF MTBE FROM A RESIDUAL GASOLINE SOURCE THROUGH IN SITU AIR SPARGING |
| Project Number | GW-71 | Staff | H. Hopkins |
| Initiation Date | January 1998 | Completion Date | First Quarter 1999 |
| Contractor | Oregon Graduate Institute |
| Objective | Air sparging may be one of the few cost effective technologies capable of remediating MTBE-contaminated aquifers in situ. This project is designed to assess the effectiveness with which air sparging can remove MTBE from a gasoline-contaminated soil and the extent to which concentrations in groundwater can be reduced downgradient of the source area. |
| Scope | A 10m by 10m by 5m deep sand-filled vault will be used as a physical model for these experiments. A "spill" of reformulated gasoline will be created in the saturated zone of model and allowed to equilibrate. An air sparging system will be installed and operated at various airflow rates. Mass removal of MTBE in the offgas will be monitored to determine the degree volatilization contributes to the total remediation. The concentration of MTBE in groundwater will be monitored before and after air sparging. |
Entered By: STEENA on 11/18/1997 11:49:58
| PHASE II - DEVELOPMENT OF MTBE AMBIENT WATER QUALITY CRITERIA DATABASES FOR THE PROTECTION OF AQUATIC LIFE |
| Project Number | WATER-12 | Staff | A. Steen |
| Initiation Date | September 1997 | Completion Date | First Quarter 1999 |
| Contractor | ENSR Laboratories and Wildlife International |
| Objective | To generate sufficient data to complete EPA guidelines for derivation of ambient water quality criteria. |
| Scope | This project is cosponsored by API, OFA, WSPA, ARCO, Shell, Texaco, and Chevron. Phase I was conducted separately. Phase II will consist of three tasks and is being conducted in coordination with EPA advisors. For Task 1 the Contractors will validate the analytical procedures for MTBE and perform range finding aquatic toxicity tests. Upon approval, definitive toxicity testing will be conducted in Task 2. This will consist of acute and chronic exposures for a suite of freshwater and marine organisms selected to meet EPA database requirements. Testing will be performed using approved SOPs and following Good Laboratory Practice procedures. Draft data reports for each test will be submitted to API and to EPA peer reviewers. An overall project report will be prepared to summarize the research findings in Task 3. |
Entered By: STEENA on 02/13/1998 13:23:56
Entered By: CLAFF on 07/24/1998 15:08:25
| OCCURRENCE, TREATMENT, AND IMPACT OF OXYGENATES IN MARKETING AND REFINERY EFFLUENTS |
| Project Number | Staff | R. Claff | |
| Initiation Date | July 1998 | Completion Date | Fourth Quarter 1999 |
| Contractor | Woodward-Clyde |
| Objective | The objectives of this study are to 1) characterize and quantify the presence of oxygenates in petroleum terminal and refinery wastewater streams and treatment processes, and 2) identify and quantify the fate of oxygenates in terminal and refinery wastewater treatment facilities. |
| Scope | A member company survey form will be distributed to refineries and terminals, requesting the submission on the presence and fate of oxygenates in industry wastewater treatment systems. These data will be supplemented by data collected in a survey of the technical literature to identify information on the fate of oxygenates in treatment systems. Survey questionnaire and literature survey data, along with physical/chemical property data for oxygenates such as MTBE and methanol, will be entered into models such as EPA's WATER8 to 1) quantify the fates of these compounds and 2) measure treatment efficiencies. A sampling program will be designed to fill in remaining data gaps. The project final report shall present the available data, the results of modeling runs, and mass balance calculations illustrating the fates of oxygenate compounds in treatment systems. |
CHARACTERIZATION OF SERVICE STATION STORMWATER RUNOFF
| Project Number | Staff | R. Claff | |
| Initiation Date | December 1995 | Completion Date | Fourth Quarter 1998 |
| Contractor | Metcalf and Eddy |
| Objective | To characterize the petroleum hydrocarbon and metals content of stormwater runoff at service stations. |
| Scope | The contractor is to collect and analyze service station stormwater runoff. The samples shall be analyzed for benzene, toluene, ethylbenzene, xylene (BTEX); oil and grease; heavy metals (Cu, Ni, Pb, Cd, Zn); polynuclear aromatics (phenanthrene, anthracene and benzo(a)pyrene); and methyl-t-butyl ether (MTBE). The contractor will also obtain ancillary information about the sampled facilities, so proper data interpretation can be made. Following sample collection and analysis, the contractor shall prepare a well-organized data summary report, including all analytical and QA/QC data for all sites and locations sampled. All associated data, including site characteristics, and meteorological and climatological data, shall also be included in this report. |
ADVANCED FUEL HYDROCARBON REMEDIATION
NATIONAL ENVIRONMENTAL TECHNOLOGY TEST SITE,
PORT HUENEME
Title: In Situ remediation of a Contaminated Aquifer, transitioned to Multi-Site Air Sparging Project
PI: Major Timothy Wiley, Air Force laboratory, Tyndall
Funding: SERDP, FY 97-98, Transitioned to ESTCP, FY98-99
The Air Force Research Laboratory, Tyndall, Florida, installed two in-situ air sparging systems in the Port Hueneme gasoline plume. This technology forces air through contaminated aquifer materials into the vadose zone where microbial degradation can take place. One was installed in the residual-phase area and the other was in the dissolved-phase portion of the plume. Data on engineering and hydrologic parameters were collected from the two systems. The sites were extensively instrumented, as well as having excess wells for high-impulse borehole radar, three dimensional electrode displays to measure aquifer electrical resistance, and miniaturized in-situ pressure sensors. Tracer gas tests have been conducted to identify air-flow distribution patterns in the aquifer, development and destruction of preferential air channels in the aquifer and vadose zone, and the influence of forced air on contamination migration. The data collected is being used to determine an accurate ground water flow rate and direction, as well as the significance of biodegradation, oxygenation and volatilization, all of which are necessary to calculate the rate and extent of treatment influence. This new data will be incorporated into the Air Force air sparging system design manual.
Title: The Effects of Higher Plants on the Bioavailability and Toxicity of Petroleum Contaminants in Soil
PI: Dr. Katherine Banks, Purdue University
Funding: US EPA, Completion 1901
Purdue University and Kansas State University have constructed a phytoremediation test containment area and planted plots with mixtures of hybrid grasses, native grasses and legumes. Four toxicity risk assessment tests to determine reduction in petroleum contaminant toxicity in soil and leachate are being conducted. Plant growth assessments will be conducted to determine the four ways interaction between contaminates, soil, microbial community, and plant roots. Reduced soil toxicity, will be an indication of improved soil health. Data obtained from this project will contribute to the overall database on the phytoremediation process.
Title: Natural Attenuation of MTBE in Groundwater, a Field Tracer Experiment
PI: Dr. Richard Johnson, Oregon Graduate Institute & Dr. Paul Johnson, Arizona State Univ.
Funding: American Petroleum Institute & college grants, Completion 1999
The study employs a solution of predeuterated 2H12 –MTBE as tracer in an already existing fuel hydrocarbon plume. Because deuterated molecules are slightly heavier than normal molecules, the tracer and its degradation products can be distinguished from existing MTBE by differences in their weight. Bromide, which has water solubility similar to MTBE, was added at a concentration similar to the concentration of the tracer, as a conservative tracer, non-biodegradable compound, with which the measurable mass of tracer MTBE can be compared. Groundwater samples was collected after the tracer injection, and will be collected every quarter for two years.
Title: Perspectives on MTBE Biodegradation and the Potential for In Situ Aquifer Bioremediation
PI: Dr. Joseph Salanitro, Equilon Enterprises (Shell Development Company) & Dr. Paul Johnson, Arizona State Univ.
Funding: American Petroleum Institute & college grants, Completion 1999
Isolated ether-degrading microbes have been inoculated in subsoil and ground water and can markedly shorten the half-life of oxygenates. The success and failure of soil inoculations to stimulate degradation of poorly biotransformed compounds depends on factors such as; (1) survival, (2) decay and rate of growth, (3) adaptation, (4) substrate/ energy utilization and availability, and (5) microbial competition. The project at the NETTS Hueneme involved injecting a biomass slurry suspension into the fuel hydrocarbon plume. The effectiveness of ether-degrading biobarriers is being evaluated with respect to factors discussed.
Title: Phytoremediation of MTBE
PI: Dr. Stuart Strand, Univ. of Washington
Funding: Navy & American Petroleum Institute, Completion 1999
Transpired gas samples were taken from eucalyptus trees growing over the NETTS fuel hydrocarbon plume to determine the presence of MTBE. Tissue samples (leaf, stem and root) were taken for analysis of MTBE and possible metabolites. These samples will be compared to similar samples from eucalyptus trees in an uncontaminated portion of the plume.
Title: Natural Attenuation of MTBE Enhanced by the Presence of Methanogenic Bacteria
PI: Dr. John Wilson, R.S. Kerr Research Center
Funding: US EPA, Completion FY00
Investigating the fate of MTBE in the presence of methanogenic bacteria activity at the NETTS plume. This investigation will determine nutrient sources, which enhance MTBE degradation.
Title: Isolation of MTBE Degrading Bacteria from NETTS Plume
PI: Dr. John Glaser, NRMRL
Funding: US EPA, Completion FY00
This project is investigating the transition from the preferential BTEX degradation to the MTBE degradation. Determination the presence of MTBE degraders is accomplished by using a phospholipid method. The factors required for the optimization of the microbiological degradation process will follow the identification of the presence of MTBE degraders.