In Situ Bio- or Chemical Remediation
Bio-Remediation systems (including processes that are NOT strictly biological) are an extension of the same processes that operate in Natural Attenuation, but are enhanced, augmented, or stimulated by human intervention. The degree to which stimulation or augmentation occurs depends on numerous factors: concentration of contaminants, presence of sensitive receptors, growth pattern of the plume, unacceptable estimated time to closure using Natural Attenuation. The choice of remediation system also depends on numerous factors, mainly related to the geochemistry and lithology of the site, along with contaminant type and concentration. The data acquired in determining if natural attenuation is appropriate are exactly the data needed to decide what active bio- or chemical remediation system is to be used and how to design its implementation. There are numerous methods used to get material or enhancements into the subsurface: trenching, placement in existing wells, or injection using drill or Direct Push rigs. ESN has developed numerous novel and powerful tools and procedures for injecting substances into the subsurface for promoting or enhancing remediation processes. The tools and procedures are designed to take advantage of the knowledge of lithology and site geochemistry developed prior to remediation and to place the substance exactly, three-dimensionally, where it is needed to optimize the results.
Petroleum Hydrocarbons
ORCŪ Injection (oxygen release) Bio-Venting using air (helium tracer gas) Fenton's Reagent Bio-Slurping Specialty microbe slurry injection Nutrient injection
Chlorinated Hydrocarbons
HRCŪ Injection (hydrogen release) Fenton's Reagent Permanganate Vegetable Oil Injection Reactive Barriers (e.g., zero valence iron) Methane or other hydrocarbon injection The capabilities of ESN's Direct Push rigs include the injection of virtually any substance into the subsurface: air, water, slurries. ESN has direct experience injecting such substances into porous, permeable formations and into hydrofractures. Only ESN has equipment specifically designed or modified for direct push & auger rigs to meet these needs.