Fairlawn Manufacturing Facility

There were two oxidation events at this site that occurred in August 2007 and February 2008, over a business day without interrupting plant activity. The site is impacted by xylenes and naphthalene.

The in-situ injection program targeted these compounds in two contaminated areas: the source and the down-gradient plume. Injections occurred between 6 and 24 feet below ground surface (bgs).

The remedial approach utilizes both free radical chemistry, oxidation chemistry and facultative biological oxidation in such a way as to extend the oxidant and free radical residuals while enhancing the in-situ environment such that it is suitable for biologically based attenuation.

IET applied three remedial materials to the subsurface via a patented injection process and apparatus (US Patent 7,044,152) such that the activation processes occur in a controlled manner in-situ. In a unique application of zero-valent iron metal, IET activated both the persulfate and the peroxide species in-situ, affecting the oxidation and biological remedial processes in a single injection process.

The first phase, oxidation, oxidizes the majority of dissolved and sorbed targeted compounds. The second phase, biological attenuation, polishes and maintains the achieved treatment goals.

A direct review of the data from the four monitoring wells located in and around the injection area indicates that the removal rates and efficacy of the treatment regime has been very successful.

This Fairlawn project demonstrates IET's patented (US 7,044,152) dual-oxidant activation technology — using zero-valent iron (ZVI) to simultaneously activate both persulfate and peroxide in a single injection event. The ZVI catalyst generates sulfate radicals from persulfate and hydroxyl radicals from peroxide, creating a multi-radical oxidative environment that destroys a broader spectrum of contaminants than either oxidant alone. The 88–97.6% reductions in ethylbenzene, xylenes, and naphthalene demonstrate the effectiveness of this approach for petroleum hydrocarbon treatment.

The two-phase treatment design — oxidation followed by biological attenuation — leverages the spent oxidant by-products as electron acceptors for facultative biological treatment. After the ZVI-activated persulfate and peroxide are depleted, the residual ferric iron and sulfate species support biological degradation of any remaining dissolved-phase contamination. This dual-phase mechanism provides both rapid source destruction and sustained long-term treatment, preventing the contaminant rebound that plagues single-oxidant ISCO programs.

The single injection process efficiency noted in the Key Success Factors reflects the advantage of ZVI-activated dual-oxidant chemistry: both oxidants are activated and delivered in one field event, eliminating the need for multiple mobilizations. The zero interruption to operations demonstrates that in-situ remediation can be performed at active facilities without impacting business continuity — a critical advantage for commercial and industrial sites.

Fairlawn, New Jersey is located in Bergen County within the Piedmont physiographic province. The shallow geology consists of Triassic-Jurassic age sedimentary rocks of the Newark Basin — predominantly red shale, siltstone, and sandstone of the Passaic Formation — overlain by Quaternary alluvial deposits. The site's petroleum contamination likely originated from historical commercial or industrial operations common to this developed suburban corridor.

The four monitoring wells in and around the injection area provided the performance data documented in the treatment results — with source area wells showing 86–97.6% reductions and down-gradient wells showing 53–74% reductions. The difference between source and down-gradient performance reflects the typical ISCO treatment pattern: highest oxidant concentrations and contact time in the source zone produce the most dramatic reductions, while down-gradient wells benefit from contaminant flux reduction as the source is destroyed.