Coal‐tar derivatives from a coal‐tar distillation and wood‐treating plant that operated from 1918 to 1972 at St. Louis Park, Minnesota contaminated the near‐surface ground water. Solutions of phenolic compounds and a water‐immiscible mixture of polynuclear aromatic compounds accumulated in wetlands near the plant site and entered the aquifer. The concentration of phenolic compounds in the aqueous phase under the wetlands is about 30 mg/1 but decreases to less than 0.2 mg/1 at a distance of 430 m immediately downgradient from the source. Concentrations of naphthalene (the predominant polynuclear compound in the ground water) and sodium (selected as a conservative tracer) range from about 20 mg/1 and 430 mg/1 in the aqueous phase at the source to about 2 mg/1 and 120 mg/1 at 430 m downgradient, respectively. Phenolic compounds and naphthalene are disappearing faster than expected if only dilution were occurring. Sorption of phenolic compounds on aquifer sediments is negligible but naphthalene is slightly sorbed. Anaerobic biodegradation of phenolic compounds is primarily responsible for the observed attenuation. Methane was found only in water samples from the contaminated zone (2‐20 mg/1). Methane‐producing bacteria were found only in water from the contaminated zone. Methane was produced in laboratory cultures of contaminated water inoculated with bacteria from the contaminated zone. Evidence for anaerobic biodegradation of naphthalene under either field or laboratory conditions was not obtained.

High-performance liquid chromatography with a cation-exchange resin-packed column was used to determine fermentation products of several known and unknown Clostridium species. The column was operated at 300C, and isocratic elution was done with 0.013 N H2S04. Sample preparation for high-performance liquid chromatographic analysis required only membrane filtration. Glucose and formate were readily determined. Quantitative results were easily obtained. Chromatograms of eight unknown strains could be matched with chromatograms of at least one of the type culture strain chromatograms. In some cases, additional testing was necessary before identification could be made. The same conclusions were reached by parallel testing with gas chromatography to determine fermentation products. High-performance liquid chromatography is simple to apply and, under some conditions, is faster than gas chromatography for fermentation product analysis.

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Field and laboratory tests were made using suspensions of baker's yeast (Saccharomyces cerevisiae) to trace movement of microbes in artificially recharged ground water. Yeast cells penetrated more than 7 meters into a sand and gravel aquifer in less than 48 hours. It is believed that most of the cells travelled through channels formed by the solution of calcium carbonate rather than through intergranular pores. Ease and sensitivity of detection, coupled with negligible background correction, suggest that baker's yeast is an excellent choice as a tracer for this type of application.