Hazardous Organic Wastes from Natural Gas Production Processing and Distribution: Environmental Fates

Hydrocarbons and polycyclic aromatic hydrocarbons are generated as waste fluids and solids throughout all aspects of natural gas production, processing, and distribution. Wastes have often been and continue to be disposed in earthen unlined waste pits sometimes near vulnerable aquifers. Wastes move from pits through soils with no apparent abatement to depths greater than roughly 2 meters. As expected, groundwater contamination does occur in river flood plains where depth to groundwater can be less than 2 meters. Contamination of groundwater and nearby soils with hydrocarbons from an unlined pit was documented in the Duncan Oil Field west of Farmington, NM. Plumes for volatile compounds including benzene, toluene, and xylenes in the water and polycyclic aromatic hydrocarbons in the soil were clearly evident downgradient from the earthen pit at distances up to 50 meters. Waste pits containing produced water and hydrostatic discharge water were found to contain large amounts of polycyclic aromatic hydrocarbons which are phototoxic to fish. Legal or illegal discharges of natural gas wastes to surface waters should be reconsidered using not only salt and heavy metal contamination but also using toxicity and mutagenicity of aromatic hydrocarbons.