Year Established: 2013 Start Date: 2013-03-01 End Date: 2014-02-28
Total Federal Funds: $10,204 Total Non-Federal Funds: $27,519
Principal Investigators: Mary Leigh, David Barnes
Abstract: Sulfolane is a toxic groundwater contaminant released from some petroleum refineries and natural gas sweetening facilities. A major plume of sulfolane-contaminated groundwater has been detected in North Pole, Alaska, which has affected over 250 private drinking water wells within a 2-mile by 4-mile region from a refinery operated by Flint Hills Resources. Sulfolane can undergo degradation in the environment through natural microbial or chemical processes. Sulfolane degradation may also be promoted using an experimental system to accelerate sulfolane degradation through injection of air into the subsurface (air sparging), which shows signs of reducing sulfolane concentrations in groundwater, and may be proposed for widespread implementation. However, little is known about how sulfolane degradation occurs, what degradation products may be produced, and the toxicity of these compounds. Knowing the identity and toxicity of sulfolane breakdown products is essential to ensuring that household water purification systems are effective at removing any compounds of concern, and that methods like air sparging reduce rather than increase groundwater toxicity. Our proposed research aims to identify breakdown products of sulfolane generated through natural and accelerated microbial and chemical processes, and then to assess the toxicity of these compounds. Experiments will be conducted using laboratory incubations of groundwater and soil from the North Pole plume and the air sparging system, advanced chemical analyses, and a sensitive toxicity assay that uses a bioluminescent bacterium (Microtox). We’ll also investigate how the toxicity of sulfolane and its degradation products to microorganisms may limit biodegradation and ultimately extend the lifespan of this contaminant plume. Our results will be immediately relevant to human health and will be informative to cleanup decisions by regulators and stakeholders.