SITE CLOSURE GOALS ACHIEVED USING ACCELERATED NATURAL ATTENUATION WITH ORC?

摘要

JJ’s Country Store in Fort Collins of Colorado noticed leaking underground storage tanks (USTs) in 1992. Groundwater contamination with BTEX was also discovered at the same time. Natural attenuation was selected as the remediation strategy. More than 90% of the BTEX was naturally attenuated in the following 4 years with several episodes of rebound during the course of attenuation. By the end of 1996, the concentration of benzene was still about 50 times greater than the Colorado Groundwater Standard (5 μg/L). Accelerated natural attenuation with ORC?, a compound that slowly releases oxygen when injected into the subsurface, was implemented in October 1997. Samples collected in May 2000 showed that the concentration of BTEX was less than 0.5 μg/L in all wells. This case study demonstrated that the accelerated natural attenuation helped to achieve the goal of site closure and ORC? is a very powerful product for the accelerated natural attenuation.