While monitoring contaminants is essential for verifying remediation efficacy at contaminated sites,  quantification of additonal parameters can increase your understanding of remediation processes. For this reason, SiREM offers competitively priced speciality chemical analytical services used to monitor and optimize remediation performance indicators including:

• Dissolved hydrocarbon gas analysis;
• Volatile fatty acids analysis; and
• Anions analysis.

Dissolved Hydrocarbon Gas Analysis

Dissolved hydrocarbon gases (DHG) analysis is used to quantify aqueous concentrations of methane, ethene, ethane, propene, propane and acetylene. SiREM’s DHG method is based on EPA method RSK-175. Use DHG analysis is used to measure important bioremediation parameters including:

• Measuring complete dechlorination by quantification of non-chlorinated daughter-products of chlorinated ethenes, ethanes and propanes;
• Quantification of methane accumulation due to methanogenesis; and
• Quantification of cometabolic substrates used in remediation of chlorinated solvents and 1,4-dioxane.

Volatile Fatty Acid Analysis

Quantifying volatile fatty acids (VFAs) in groundwater is a sensitive way to measure electron donor longevity and distribution in bioremediation systems. Commonly used electron donors including lactate and emulsified vegetable oils, ferment to produce a variety of VFAs and hydrogen used in reductive dechlorination. Furthemore, all VFAs are not created equal with propoinate and butyrate being superior to acetate for reductive dechlorination. SiREM uses a custom ion chromatographic method to quantify lactate, acetate, propionate, formate, butyrate and pyruvate.

Use VFA quantification to:

• Confirm fermentation of slow release or soluble electron donors;
• Track distribution and dispersion of electron donor; and
• Determine the need for additional electron donor amendment to promote complete reductive dechlorination.

Anion Analysis

Anions are used to assess groundwater water quality, redox conditions, and as stable tracers in remediation systems. During bioremediation, the onset of reducing conditions species like nitrate and sulfate are reduced to their less oxidized states (i.e., nitrogen gas and sulfide). These changes in nitrate and sulfate concentrations can indicate that biologically mediated changes in the redox of the aquifer are occurring. The concentrations of nitrate and sulfate also impact the required dosing of electron donors, as these species often consume more electron donor than contaminants themselves. SiREM uses a custom ion chromatographic method for anions quantification based on US EPA Method 300 to quantify chloride, bromide, nitrite, nitrate, sulfate and phosphate.

Use Anion quantification to:

• Assess the concentrations of redox-sensitive anionic species;
• Confirm the onset of suitable reducing conditions required for the reduction of chlorinated compounds;
• Chloride is release during reductive dechlorination, increases in chloride can be a conservative indicator of the extent of reductive dechlorination.
• Determine the groundwater velocity and flow path using stable anionic tracers

For More Information on SiREM’s Analytical Testing Services
Visit https://www.siremlab.com/analytical-testing/ or contact Brent Pautler at bpautler@siremlab.com.