No abstract

Soil samples were obtained at four depths from 0 to 121 cm below unlined earthen waste pits associated with production, processing, and distribution of natural gas in the San Juan basin of northwest New Mexico. Sample extracts were analyzed by using capillary gas chromatography and gas chromatography/mass spectrometry for polycyclic aromatic hydrocarbons (PAH) to characterize potential for contamination of shallow groundwater. All soils contained complex mixtures of over 60-100 resolved hydrocarbons with carbons numbering from 10 to 45. Extracts were prefractionated for PAH quantification, due to complexity and concentration of interfering hydrocarbons. Over 30 PAH and alkylated PAH at total concentrations of 30-683 mg/kg were detected in soil samples. While concentration profiles for two-ring PAH showed a 20-fold decrease with depth at the produced water pit, less striking reductions were seen with the same compounds at the dehydrator and pipeline drip pits. Moreover, threeand four-ring PAH showed no appreciable variation with depth in any pit. Contamination of shallow groundwater a t depths of 1-2 m in flood plains of river valleys in New Mexico from wastes in unlined earthen pits is possible and likely.

Discussion of breakthrough phenomenon and an experiment to identify the organic compounds present in natural gas through gas chromatography.

No abstract

No abstract