EAM           Environmental & Analytical Management, Inc.

 

MOBILE/PORTABLE ENVIRONMENTAL CHEMISTRY, RESEARCH AND ANALYTICAL SERVICES WORLDWIDE

 

Remediation by Natural Attenuation and Intrinsic Bioremediation FAQ’s

 

Why are mobile/portable analytical systems needed for natural attenuation studies?

 

EAM designs and operates analytical systems that maximize representativeness, accuracy and precision. All data generated by EAM is conducted in accordance with USEPA methods and Quality Assurance procedures, resulting in scientifically and legally defensible data (1,2,3). The understanding of continuous biogeochemical equilibriums and cycles that occur in groundwater ecosystems can be quite complicated (4). The moment a sample is removed from the biogeochemical equilibriums that exist in-situ, the water chemistry of the sample begins to change. Sampling procedures, temperature and pressure variations, removal from geological contact, exposure to the atmosphere, photo-degradation, biodegradation, preservation, containerization and transportation effect the chemistries of the compounds of interest. When one looks at these data variables and applies the data for quantitative interpretation (i.e. numerical modeling), the range of output could be significant, rendering data with low confidence levels. These issues identified in the research conducted by the American Petroleum Institute (5,6), DOD (7), USEPA (8,9) and industry (10), are beginning to be understood during the evaluation process of natural attenuation data. Analysis of the sample, at the sampling location, moments after low- flow and turbulence purging and sampling will maximize sample representativeness, and eliminate a significant group of variables associated with the sampling and analysis plan design.

 

How did EAM develop the Natural Attenuation Parameter Analytical System?

 

EAM prepared work plans to conduct quarterly monitoring and natural attenuation parameter sampling and analysis in accordance with the several guidance documents authored by various DOD agencies, the USEPA and industry referenced above. EAM’s natural attenuation experience includes QA plans, sampling and analysis plans, analyses, data evaluation, validation, management and reporting at Superfund projects, petroleum, chlorinated-solvent and co-mingled plume projects. These projects were developed using the data quality objectives process (DQO) developed by the USEPA (11).

 

How do you determine if natural attenuation is occurring at your site?

 

In the past, an investigation process similar to a contamination assessment approach described in USEPA QA SOP’s (13) were used to determine contaminant spatial mass and hydrogeological conditions. The various guidelines and protocols mentioned above have developed flow charts for the evaluation of natural attenuation. Most guidelines and protocols describe a “three lines of evidence approach” to evaluate the efficacy of natural attenuation.

 

What are “lines of evidence”?

 

Typical lines of evidence include contaminant mass depletion, redox potential contours, spatially defined electron accepting processes, breakdown product identification and quantification, hydrogen mass concentrations, phospholipid fatty acid analyses and microbe enumeration.

 

Can we determine or predict contaminant degradation rates?

 

When using natural attenuation data for quantitative purposes, the representativeness and accuracy of the sampling and analytical system can significantly effect the data output, which can render atypical electron accepting process distributions and inaccurate degradation rate calculations (13). A natural attenuation study that can be used for regulatory purposes must produce scientifically and legally defensible data with a defined and appropriate confidence level. The use of a consistent mobile analytical system will provide scientifically and legally defensible data of known data quality, with maximum representativeness of the in-situ biogeochemical equilibriums. Verification of the data can be shown by model predictions and evaluating them at the next data collection interval, followed by model calibration and repeating the process. This type of data provides a high confidence level of the natural attenuation processes occurring at the site.

 

How do we develop legally and scientifically defensible data?

 

The USEPA’s Data Quality Objectives Process and the individual USEPA methods define the QA requirements and documentation for a laboratory to generate data of known quality. As you go through the DQO process, the data confidence and quality is defined and specific QA protocols are determined. Well construction methods such as direct push technology and groundwater purging/sampling methods must be understood to produce representative/reproducible data sets (14).

 

 What are some of the analytical data quality considerations when designing a sampling and analysis plan?

 

When using a commercial laboratory, sample bias due to constituents that interfere with the analytical method are not commonly reviewed. Most analytical methods discuss the potential interferences and chemistries that can bias the analytical result. The variables associated with the site specific analytical system and quantification of the variables should be identified. Data validation should be conducted on all data sets. Well construction details and screen intervals, as well as local geology should be understood. Matrix interference issues and confidence levels required for the data user should be defined.

 

EAM SERVICES, EXPERIENCE AND QUALIFICATIONS

 

EAM has operated mobile analytical systems designed for the analysis of herbicides and pesticides, PAH’s, PCB’s, natural attenuation studies of petroleum and chlorinated solvents, and conducts air analyses for landfill gases, industrial hygiene sampling and analysis in accordance with NIOSH methods, as well as ambient air monitoring systems. EAM personnel have designed and operated mobile analytical systems for tracer studies, assessments, emergency response analysis, water treatment system diagnosis, groundwater monitoring and natural attenuation studies. Analytical systems operate in accordance with USEPA quality assurance methods and the data quality objective of quantitative data. EAM provides specialized sampling services including low-flow groundwater purging and monitoring with down-hole or flow-through sensor arrays. The data generated by the analytical systems are in an electronic database format (Microsoft Access), and can be downloaded into spreadsheets, sent via e-mail or printed into EAM’s report format.

 

 

NATURAL ATTENUATION ANALYTICAL PARAMETERS AND METHODS

 

 

-pH

150.2

Temperature

170.1

ORP

NA

Dissolved Oxygen

360.1

Conductivity

120.1

Nitrate

354.3

Ammonia

350.3

Nitrite

354.1

Sulfate

375.4

Sulfide

376.2/9215

Iron, Total

3500-Fe D

Iron, Ferrous

3500-Fe D

Alkalinity

310.1

Chloride

325.3/92539212

Manganese +II, +IV

8034

Volatile Organic Compounds including breakdown products 8021B

Carbon Dioxide, Methane, Ethane and Ethene   RSKSOP-114 (15)

 

 

REFERENCES AND LINKS

 

The popularity of natural attenuation is increasing. Site cleanup plans are now being written and re-written to include it, conferences and guidelines are conducted and produced. Below are listed several pertinent references and links to natural attenuation sites. All of these are listed when using search engines with the key words of “natural attenuation”.

 

1)                   Methods for Chemical Analysis of Water and Wastes, EPA-600/4-79-020, March 1983,

2)                   Standard Methods for the Examination of Water and Wastewater, 18th  edition, 1992,

3)                   Test Methods for Evaluating Solid Waste, Third Edition, SW-846, USEPA Office of Solid Waste and Emergency Response, Washington D.C.

4)                   Ground-water Microbiology and Geochemistry, Francis H. Chapelle, USGS, John Wiley and Sons, 1992.

5)                   Effects of Sampling and Analytical Procedures on the Measurement of Geochemical Indicators of Intrinsic Bioremediation: Laboratory and Field Studies, American Petroleum Institute, Health and Environmental Sciences Department, Publication Number 4657, November 1997.

6)                   Methods for Measuring Indicators of Intrinsic Bioremediation: Guidance Manual, American Petroleum Institute, Health and Environmental Sciences Department, Publication Number 4658, November 1997.

7)                   Technical Protocol for Implementing the Intrinsic Remediation with Long-term Monitoring Option for Natural Attenuation of Dissolved- Phase Fuel Contamination in Ground Water, Wiedemeier, T.H., Downey, D.C., Wilson, J.T., Kampbell, D.H., Miller, R.N., and Hansen, J.E., Air Force Center for Environmental Excellence in cooperation with the USEPA, Brooks Air Force Base, San Antonio, Texas.   7/31/94.

8)                  USEPA OSWER DIRECTIVE, Natural Attenuation http://www.epa.gov/OUST/directive/9200_417.htm

9)                  Draft USEPA Region 4 Suggested Practices for Evaluation of a Site for Natural Attenuation (Biological Degradation) of Chlorinated Solvents, November 1997, Version 3. http://www.epa.gov/region 4/wastepgs/oftecser/protoexp.pdf

10)              Guidance Handbook on Natural Attenuation of Chlorinated Solvents, prepared by the Bioremediation of Chlorinated Solvents Consortium of the Remediation Technologies Development Forum (RTDF), September, 1996 http://www.icubed.com/rtdf/

11)               Data Quality Objectives Process for Superfund, Interim Final Guidance, EPA 540-R-93-071, September 1993,

12)               USEPA Environmental Investigations Standard Operating Procedures and Quality Assurance Manual, USEPA Region 4, May 1996,

13)               Site Characterization: What Should We Measure, Where (When?), and How?, Michael Barcelona, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI,

14)               Evaluation of Sampling and Analytical Methods for Measuring Indicators of Intrinsic Bioremediation, American Petroleum Institute Soil and Groundwater Research Bulletin No. 5, March 1998,

15)               Dissolved oxygen and Methane in Water by GC Headspace Equilibration Technique, Kampbell, D.H., Wilson, J.T., Vandergrift, S.A., Inter. J. of Envir. Anal. Chem., Vol. 36, pp 249-257.

16)               Hydrogen concentrations in a Landfill Leachate Plume (Grindsted, Denmark): In Situ Energetics of terminal Electron Acceptor Processes, Jakobsen, R,et al, EST 1998, 32, 2142-2148

17)               BIOSCREEN   -           http://www.epa.gov/ada/kerrlab.html

18)               PARSSIM1        -           3-D intrinsic bioremediation simulation http://king.ticam.utexas.edu/Groups/SubSurfMod/ColorPictures/figure3.html

19)               University of Waterloo, bioremediation and groundwater microbiology course. http://bordeaux.uwaterloo.ca/biol447new/bfss.html

20)               BTEX Metabolism Metapathway Map: http://dragon.labmed.umn.edu/~lynda/BTEX/BTEX_map.html

21)               Anaerobic Mineralization of Vinyl Chloride in Fe(III) Reducing Aquifer Sediments, Bradley, P.M., Chapelle, F.C., Envir. Sci. & Tech.,, Vol. 30, No. 6, 1996

22)               Several groundwater and natural attenuation models can be reviewed at: Waterloo Hydrologic, Inc.  http://www.flowpath.com

23)               The Sandia Natural Attenuation Project, Monitored Natural Attenuation Toolbox (site screening tool)    http://www.sandia.gov/eesector/gs/gc/na/mna_cbz.html

24)               Insitu Bioremediation Software, Edwards AFB – http://en.afit.af.mil/env/insitubio.htm

25)             Micropurge homepage provides research on low flow and turbulence pumping and sampling systems. http://www.micropurge.com

 

Contact Sven R. Pavlovics, Environmental Scientist for additional information at 561-792-9190 or eamlabs@eamlabs.com .