Realizing Petroleum Hydrocarbon Destruction via Biostimulation Alone; Importance and Benefits of Biofilm Development

Proof-of-Concept study to evaluate efficacy of biostimulation additive TPHenhanced to enhance native heterotrophic bacteria populations ability to degrade petroleum hydrocarbon contaminants (PHCs) under anaerobic conditions. State Agency wish low-impact low-cost strategy to sustainably remediate remote/legacy PHC impacted sites without Oxygen (O2) and/or aboveground support equipment. Site former gas-station converted into fast food restaurant. Underground storage tanks (USTs) removed; however, past use adversely impacted on/off-site saturated soils/groundwater.

Limited test zone amended over 6-month period using additive filled passive release sock (PRS) deployment units; 2-pounds additive each, 2 units deployed per event. Passively creates ≈3-5-foot area-of-influence (AOI). PRS units suspended within saturated screened interval of monitoring well MW-44, proximate to off-site contaminant plume center, with groundwater [Benzene] 19.6 mg/L in March 2019. PRS units replaced ≈2-week intervals from July 16, 2019 through November 8, 2019 with baseline [Benzene] 7.73 mg/L and suspected residual mass present. Concentrations total volatile petroleum hydrocarbons (TVPH), 31.6 mg/L, [Nitrate] (NO3) 515 mg/L.