As part of Microseeps' commitment to providing its customers with an assortment of training materials and resources, we are now pleased to host free e-training sessions covering a range of topics including Compound Specific Isotope Analysis, Monitored Natural Attenuation, Dissolved Gas Sampling and more. To learn more, click here

Microseeps and Microbial Insights Will Introduce Their First Collaborative Achievement at the Battelle Conference in Monterey,  CA in May 2006.

Microseeps and Microbial Insights, two cutting edge specialty environmental services companies, will introduce their first collaborative achievement at Battelle’s Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 22-25 in Monterey, California.

Microseeps, a leading specialty environmental geochemistry firm, has been on the forefront of new methods and technologies for assessing in-situ degradation of subsurface contaminants.  Microbial Insights has pioneered the field of environmental microbiology by offering a unique set of molecular biological tools to facilitate intelligent site design and management decisions.  The two companies have established a collaborative relationship designed to foster innovation and new technologies.

At the Battelle Conference, the firms will introduce their first technical achievement, a new 5-step process for demonstrating that biodegradation processes are occurring or can occur at a given site.  This process offers significant advantages on sites where monitored natural attenuation (MNA) or enhanced bioremediation may be the remdiation method of choice. 

 Microbial Insights in a collaborative effort with Microseeps has expanded the capabilities of Bio-Trap Samplers to not only determine the microbial response, but to also assess the presence and acceleration potential of degradation of a given contaminant in-situ.  This collaborative achievement involves the use of Bio-Trap Samplers which have been baited with known concentrations of contaminants or surrogates (13C enriched petroleum hydrocarbons or fuel oxygenates and fluorinated analogs of chlorinated solvents).  This process can effectively answer whether a contaminant is being degraded by indigenous microbes or if a particular amendment would accelerate the biodegradation rate at a site.

Microbial Insights, Inc. is an environmental biotechnology company based out of Rockford, Tennessee.  The company develops and applies cutting edge genetic and chemical diagnostic tests that describe and quantify microbes and microbial communities.  Microseeps, Inc. is a specialty analytical laboratory located in Pittsburgh, Pennsylvania.  Microseeps is a recognized leader in the development of specialized analytical methods to support monitored natural attenuation and other in-situ remediation techniques.  Together, this unique collaboration facilitates integrated solutions through a comprehensive understanding of environmental data.

Using Low Ethene Concentrations to Discern Chlorinated Ethene Natural Attenuation

Patrick W. McLoughlin, Robert J. Pirkle - Microseeps Inc. and John Catches - Jones Edmunds & Associates, Inc. Gainesville, FL

A former municipal landfill in Georgia was contaminated with concentrations of tetrachloroethene (PCE), cis-1,2-dichloroethene (cDCE), 1,1-dichloroethene (11DCE) and some other trace solvents. The chlorinated ethene concentrations were low, but exceeded the Georgia Environmental Protection Division’s maximum contamination level (MCL).

The contamination exists in a surficial aquifer. Specifically, this site is underlain by at least 50 feet of very fine to coarse-grained clayey sands, sandy clays and clay. The site hydraulic conductivity is 10-5ft/min, leading to an estimated ground water seepage velocity of 14 ft/yr. Public supply wells extend far below the contaminated aquifer and only four private potable water wells are within a 0.5-mile radius of the site, all of which are located either up?]gradient or side-gradient of the site and are not threatened by the contaminant plume. Because of this monitoring only was conducted for several years.

There appeared to be a decline in concentrations, but noise made the data such that there was no obvious trend. Throughout four semiannual samplings, a full suite of geochemical parameters was measured to see if a case could be made for monitored natural attenuation (MNA). That sampling revealed low (<0.1 ug/l) ethene concentrations. Despite the magnitude of those concentrations, they were clearly above background and indicated active complete reductive dechlorination. The ethene observation meant that, despite several misleading preliminary indications that MNA was not significant, a thorough assessment of the contribution of MNA was warranted. A procedure for such an assessment was conceived of and executed.

cDCE was the most substantial problem. A Mann-Kendall analysis showed the cDCE concentrations to be declining. Hits of ferrous iron and nitrite indicated that there were reducing conditions at the site but dissolved oxygen (DO) ranged between 1-9 mg/l, suggesting that the site was only mildly anaerobic. DO was seen to be directly correlated with DCE concentrations. This correlation was seen as an inhibition of the reductive dechlorination and the fact that DO temporarily reversed the declining trends meant that those trends were dominantly the result of biodegradation.

Point decay rates were then calculated for two wells, one currently containing cDCE below the MCL and another containing cDCE above the MCL. The first validated the model, and the second predicted the cDCE concentration to be below the MDL by 2007.

Implications From An Overview of Volatile Fatty Acid and Ethene Observations

Patrick W. McLoughlin, Robert J. Pirkle (Microseeps, Inc. Pittsburgh, PA)

Volatile fatty acids (VFA 's) have long been recognized for their ability to stimulate reducing conditions in ground water. However, the ability to measure a spectrum of ground water VFA concentrations in a sensitive and reliable manner has only recently become available. While biochemists recognize the many roles of VFA's, concentrations have been interpreted for little more than their potential to stimulate reducing conditions.

Ethene is the product of complete reductive dechlorination. While many laboratories only provide minimum reporting levels of 1 ug/l or even higher, it is becoming recognized that for sites exhibiting only slow but significant dechlorination, the ethene concentrations may be below these levels.

Using sensitive analyses for both VFA’s and ethene, data was recorded from 1055 samples. That dataset, comprised of results from samples from a wide variety of sites and remediation techniques, was analyzed for correlations that would help environmental professionals use volatile fatty acid concentration data to make informed decisions about site management.

Three such correlations were found. An index of the VFA profile was chosen and with that three more correlations were found. These correlations are significant because they link VFA concentrations and the ratio’s of those concentrations to complete reductive dechlorination, demonstrating the utility of using sensitive analyses for both VFA’s and ethene.

Microseeps offers solid phase analyses to assess the quantity of iron that can participate in bioremediation

Microseeps has refined and is performing a suite of analytical methods for clients who seek more definitive evaluations of their sites.Over the last decade, Microseeps has developed the means to determine that intrinsic biodegradation is an active process at sites by studying their aqueous geochemistry. There is growing evidence that these efforts may be helped by consideration of the minerals which participate in bioremediation as well as those which accumulate as a result of the in-situ redox processes associated with each plume, particularly the reduced iron and sulfur minerals.  Bioavailable ferric iron (BAFeIII) analysis is used to assess the quantity of iron that can participate in bioremediation.  Aqueous and Mineral Intrinsic Bioremediation Analyses (AMIBA) are used to assess the quantity of reduced iron and sulfide bioremediation products. These analyses can be used to evaluate site suitability for natural attenuation and for monitoring effectiveness and efficiency of ongoing natural attenuation. Microseeps offers these analyses in three different combinations: BAFeIII alone; the AMIBA suite; and AMIBA with BAFeIII.

BAFeIII analysis is useful to:

• Prove that iron added in an “iron wall” treatment can also increase the bioremediation capacity of an aquifer by measuring the quantity of iron that can be used in bioremediation.
• Measure how much carbon substrate (e.g. ethanol, HRC® or molasses) would be consumed in “burning through” the bioavailable ferric iron and establishing methanogenesis.
• Assess the assimilative capacity of an aquifer into which a petroleum product has been released.
  
  
  The BAFeIII analysis is performed using test kits developed by CDM and manufactured by New Horizons Diagnostics Corporation.  BAFeIII test kits have been demonstrated and validated at multiple sites by the Naval Facilities Engineering Service Center (NFESC) and CDM under the Department of Defense Environmental Security Technology Certification Program (ESTCP).
  

AMIBA analyses are useful to:

• Quantify the mineral products of petroleum hydrocarbon biodegradation. Since they go into the solid phase, it is required that the solid phase be measured.
• Differentiate between iron that is immediately available for biodegradation and iron that is less readily available.
• Evaluate the minerals previously produced by biodegradation.
• Characterize the extent of reduction in the mineral phase and assess the potential for abiotic remediation.