ABSTRACT

Recent projects where sites had both soil and groundwater contamination from historical and recent petroleum releases were remediated below regulatory action limits using affordable and economic technology without employing the use of expensive bio-remediation systems. Enhancing natural bio-remediation by manually introducing microbes, nutrients, and oxygen donor "socks" into the groundwater wells kept the microbes working at optimum levels. Three sites with varying backgrounds, geology, contamination levels, and in situ levels of natural nutrients and oxygen were remediated. One site had petroleum contamination in several wells, with dissolved-phase hydrocarbon values in thousands of parts per billion over a period of ten years. The site had a proposed Corrective Action Plan (CAP) to eventually remediate the contamination for a cost in excess of a quarter million dollars. Using enhanced natural bio-remediation technologies, the wells were injected for a fraction of the originally proposed cost. The site received a "no further action" one year after initiating bio-remediation. The other two sites were treated in a similar manner obtaining the same outstanding results at minimal cost. Constant fine tuning of the process now allows a much wider application of these principles, including remediation of dry cleaning solvents and other constituents of hazardous waste.