Biosparging is an In-Situ remediation technology that uses indigenous microorganisms to biodegrade organic constituents in the saturated zone. In biosparging, air (or oxygen) and nutrients (if needed) are injected into the saturated zone to increase the biological activity of the indigenous microorganisms. Biosparging can be used to reduce concentrations of petroleum constituents that are dissolved in groundwater, adsorbed to soil below the water table, and within the capillary fringe. Although Biosparging can also treat constituents adsorbed to soils in the unsaturated zone, Bioventing is typically more effective for this situation if the indigenous microorganisms are of a high enough consentration to reduce concentrations of petroleum constituents in a timely manner.

When volatile constituents are present, Biosparging is often combined with Soil Vapor Extraction (SVE) or Bioventing and can also be used with other remedial technologies. When Biosparging is combined with Vapor Extraction, the vapor extraction system creates a negative pressure in the vadose zone through a series of extraction wells that control the vapor plume migration. A Biosparging pilot test or respirometery test is recommended.
When used appropriately, Biosparging is effective in reducing petroleum products at underground storage tank (UST) sites. Biosparging is most often used at sites with mid-weight petroleum products (e.g., diesel fuel, jet fuel); lighter petroleum products (e.g., gasoline) tend to volatilize readily and to be removed more rapidly using air Sparging. Heavier products (e.g., lubricating oils) generally take longer to biodegrade than the lighter products, but Biosparging can still be used at these sites. Additionally, one must recognise that it is critical to the process that the exact environment be maintained to insure that the indigenous microorganisms are promoted to grow to biodegrade the contaminants.