SiREM offers chemical analytical services that provide multiple lines of evidence to support nuanced understandings of how remediation processes are performing. When SiREM’s specialized analytical testing is combined with Gene-Trac® testing, in the field, or in treatability studies, it greatly enhances our understanding of remediation progress and assists decision making to optimize remediation strategies.
Consider our customizable SiREMNA package, which adds chemical and Gene-Trac® testing chosen for your particular site, based on media, contaminants, microbes present, and other features.
Our NitroGen package which provides critical data to understand and manage nitrogen-impacted sites and treatment systems.
SiREM’s DHG analysis can confirm whether or not chlorinated ethenes and ethanes have dechlorinated completely by measuring ethene and ethane. Also, measuring the methane formed by the respiration of anaerobic microbes during ananerobic bioremediation can be a useful indicator of methanogenensis, a process often observed during reductive dechlorination or anaerobic hydrocarbon degradation. Alternatively, consumption of methane during cometabolic bioremediation provides a line of evidence that cometabolism is working. Once remediation practitioners have a clear picture of what is happening in the bioremediation process they have implemented, they can make decisions about the need to add additional amendments or not.
SiREM’s custom DHG method is based on a modified RSK-175 method developed by the United States Environmental Protection Agency (USEPA).
Standard List:
Upon Request:
When commonly used electron donors (e.g., lactate, emulsified vegetable oils [EVO], and alcohols) ferment, VFAs are often produced. Detecting increasing concnetrations of VFAs suggests active electron donor fermentation and that hydrogen—the ultimate electron donor used by many reductive dechlorinators—is likely being generated.
By measuring the amount of volatile fatty acids (VFAs) in treated groundwater, SiREM provides data that can confirm whether or not additional electron donor needs to be injected into the study area to complete reductive dechlorination. Using this data for guidance removes the risk of adding more electron donor when it is unnecessary, which saves money. Measuring VFAs provides insights into electron donor status that are simply not provided by analyzing total organic carbon (TOC).
As reducing conditions are reached during bioremediation, common polyanionic species like nitrate and sulfate are reduced to their less oxidized states (in this case, nitrogen gas and sulfide). These changes in nitrate and sulfate concentrations often indicate that oxidation-reduction reactions are occurring within an aquifer due to actions of microorganisms which is consistent with the onset of anerobic bioremediation.
SiREM’s anion analysis measures anions to assess the concentrations of redox-sensitive anionic species, including nitrate and sulfate, which can confirm that suitable reducing conditions have been achieved so that reductive dehalogenation can occur. Chloride measurement can also be used as another line of evidence for dechlorination at contaminated sites with very high chlorinated solvent concentrations.
In addition, stable anionic tracers, such as bromide, can be used to trace groundwater velocity and flow paths.
Natural Oxidant Demand Analysis
Natural, or matrix, oxidant demand (NOD) is a key factor that impacts the cost of in-situ chemical oxidation (ISCO) remediation, and therefore, its feasibility. The magnitude of permanganate NOD is strongly correlated to the amount of oxidant that will be needed to overcome the oxidant demand of geologic materials and of the compounds of concern themselves.
SiREM’s NOD tests are used to assess oxidant dosing requirements when designing and implementing ISCO remedies in the field or planning for ISCO treatability studies. We conduct all NOD tests using ASTM methods and other established industry protocols to reliably measure the NOD of site samples. We are adept at testing for permanganate NOD and persulfate oxidant demand using a variety of activation chemistries.
Compound-Specific Isotope Analysis (CSIA)
Quantify and characterize the in-situ degradation processes of compounds at your site to help build a reliable remediation and monitoring strategy.
