The Effectiveness of Using Automated Belt Oil Skimmers as a Method of Well Remediation

In many sites across the country, groundwater has been contaminated by petroleum products due to leaky underground tanks or past spills. If the leak has gone unnoticed, a considerable amount of product could exist in an aquifer (underground water reservoir), and may be trapped in the surrounding rock. Remediation can take months or years to complete and is frequently labor intensive and costly. Options include pump and treat systems, bacteria treatment, manual skimming, and automated skimming. Contamination can range from very light LNAPL (Light Non Aqueous Phase Liquid), such as gasoline, diesel, or kerosene, to very heavy DNAPL (Dense Non Aqueous Phase Liquid) like creosote or bunker c. Sometimes multiple contaminations exist in the same aquifer. Skimming is an effective method of well remediation as shown from three site examples in New Mexico, Colorado, and Alabama. Benefits include various options to minimize labor, which are particularly suited to remote applications. A few disadvantages exist, such as the inability to guarantee removal to very low parts per million or to pick up contaminants besides petroleum products. However, at the three sites studied, skimming was shown to remove many gallons of oil over varying lengths of time, with the limiting factor being the refresh rate of the well.