The Alternative To Pump And Treat

By Bob Thibodeau, Product Manager
Abanaki Corporation; Oil Skimmer Division

Skimming devices, especially belt skimmers, should be given serious consideration for groundwater remediation.

Sometimes, an important technological advance begins with a small step – back! Such is the case with remediation of hydrocarbons from groundwater utilizing existing recovery and monitoring wells.

For the past few years, state government has based decisions on the amount of clean up that they require by the risk posed to the environment. Risk Based Corrective Action, commonly called "Rebecca" (RBCA), is a process that utilizes the principles of exposure assessment, toxicity and mobility to make corrective action decisions on sites that are cost effective while still protecting human health as well as that of the environment. Many times all they require is removal of the free-phase product, allowing any emulsified contaminant to degrade with time. RBCA has saved many millions of dollars both for taxpayers and for businesses. With state regulatory agencies taking this approach, oil skimming devices have emerged as one of the most cost effective means of remediation.

Wastewater engineers in industrial settings have, for many years, understood the value of skimmers in the removal of hydrocarbons from water. Food processing plants, the metals industry, machining firms and utilities have all used skimmers with great success for wastewater treatment. Recently, skimmer manufacturers have modified their product for remediation of groundwater. The skimmer's ability to get into tight spaces and remove relatively large amounts of hydrocarbons lends itself perfectly to groundwater remediation.

Since most oils, fuels and other hydrocarbon liquids have the tendency to float on water, skimmers are designed to remove only the top, free-phase, product layer. With only product being removed, the cost and maintenance of other down-well and water treatment equipment can be eliminated. Another cost advantage to skimming is that in many cases the product can be salvaged for reuse - further reducing the overall price by eliminating the disposal cost.