Groundwater remediation is the process of removing hydrocarbons that are located underground as a result of spills or leaks. The goal of removing these contaminants is to protect the health of public water resources and the surrounding environments and communities.

Oil skimmers, particularly belt skimmers, are extremely adept at removing hydrocarbons like DNAPLs, LNAPLs, and fuel oils from monitoring or remediation wells. Unlike pump-based systems, oil skimmers require very little maintenance, are easily installed, can be portable, and have minimal power requirements.

Abanaki’s PetroXtractor, for example, is a prime choice for groundwater remediation applications. The unit can often remove hydrocarbon concentrations to acceptable EPA levels alone. By weaponizing the differences in specific gravity and surface tension between oil and water, the Petro uses an oleophilic (oil attracting) belt to cycle through contaminated water, carrying oils upwards of a hundred feet to be scraped off and disposed of.

“DNAPL” is an acronym for dense, non-aqueous phase liquid. DNAPLs are liquid chemicals that are heavier than water and that are only slightly soluble in it. In the context of groundwater contamination, DNAPLs travel all the way down through the water table until they encounter a surface that prevents downward movement. Typical examples of DNAPLs include creosote, coal tar, and solvents.

“LNAPL” is an acronym for light, non-aqueous phase liquid. LNAPLs are liquid chemicals that are lighter than water and will not become soluble in it. When they enter groundwater, they float on top of the underground water table. Examples of LNAPLs include gasoline, diesel fuels, and various other petroleum products.

In groundwater remediation applications, oil skimmers are designed to remove hydrocarbons, including LNAPLs and DNAPLs from the top, free phase product layer of groundwater.

For groundwater remediation applications, Abanaki recommends the PetroXtractor, as monitoring wells are typically 2”, 4″, and 6″ in diameter. There are, however, rare occasions when wells are wide enough to accommodate a larger model of skimmer.

Depending on the skimmer’s model and application requirements, belts can drop 100+ feet into wells to reach the water/product interface. Driven by an above ground motor, the belt then passes through the water to collect hydrocarbons and carries them back up to a set of wipers that scrape off the product for collection and disposal. The endless cleaned belt then cycles back into the well to continue collecting free-phase product.

For groundwater remediation applications, Abanaki offers standard electric motor options, solar + battery options, and other specialized motor configurations as needed in applications where motors may need to be explosion proof due to the presence of fuel oils.

Factors like efficiency, initial cost, and operating cost are all taken into account when comparing oil skimmers to pump and treat systems. Other factors include the remediation site’s specific layout, regulation requirements, and any private concerns. There are situations where a pump and treat approach is more ideal for groundwater remediation, and there are also situations where an oil skimmer is a much more viable option.

An oil skimmer can also be used in conjunction with pump and treat systems. Once the oil/water solution is pumped to the surface and into a holding tank, the skimmer can remove oil when it settles on the surface.

Pump and treat systems, including bailing and slurping, are similar to oil skimmers in that they range in their effectiveness and cost requirements. For our full discussion on the comparison between oil skimmers and pump and treat systems, we recommend this article: The Alternative to Pump & Treat

Oil skimming aids in helping restore groundwater to EPA regulated levels of contaminants. In groundwater remediation applications, oil skimmers are designed to remove DNAPLs, LNAPLs, and other hydrocarbons from the surface of groundwater. Effective remediation is critical for protecting both public health and the surrounding environment.