Lancaster Former Glass Facility

A remedial event was conducted at a former glass facility to address soils and groundwater impacted by both the historical release of chlorinated solvents and metals contamination.

The primary compounds of concern at the site were CVOCs and metals such as Arsenic, Chromium, Mercury, and Lead. An injection program was proposed by IET for the remediation of VOC impacts and to promote metals precipitation at the site utilizing reductive technologies.

The injection program was implemented between July 16-21, 2012, throughout one treatment area encompassing approximately 11,285 sq ft from 15 to 24 feet below ground surface.

The 50 injection locations in the permeable reactive barrier (PRB) were completed with a comprehensive mix of remedial materials designed to address both organic and inorganic contaminants.

Concentrations of Lead, Selenium and Tetrachloroethylene (PCE) were positively impacted by the injection process with major decreases recorded during the post-injection sampling events across multiple monitoring wells.

This Lancaster project demonstrates IET's capability to treat both organic contaminants (PCE) and inorganic contaminants (lead, selenium) in a single permeable reactive barrier (PRB) installation. The 50-injection-point PRB was constructed with a comprehensive amendment mixture totaling 10,575 gallons — including 10,335 lbs of ZVI, 14,100 lbs of Provect-IRM, 4,695 lbs of calcium propionate, 1,410 lbs each of sodium sulfite and yeast extract, 399 lbs of blue-green algae, and 705 lbs of nutrient.

The ZVI component addresses both contaminant classes: it provides abiotic reductive dechlorination of PCE through direct electron transfer at the iron surface, and it immobilizes dissolved lead and selenium through precipitation as insoluble metal sulfides and iron-metal co-precipitates. Provect-IRM (a controlled-release organic substrate containing ZVI) provides the biological component — slowly fermenting over 3–5 years to release hydrogen donors that sustain reductive dechlorination and create the anaerobic conditions needed for metal precipitation.

The 50 injection points across the PRB alignment ensure comprehensive lateral coverage of the contaminant plume, with each point delivering the amendment cocktail at the target treatment depth. The PRB approach creates a permanent subsurface treatment zone that destroys contaminants as groundwater flows through it — providing long-term plume control without the need for continuous active treatment or repeated mobilizations.

Lancaster, Pennsylvania is located in Lancaster County within the Piedmont physiographic province, but the site's glacial till geology (noted in the Key Success Factors) indicates a localized deposit of Quaternary-age glacial drift — predominantly clay, silt, sand, and gravel mixtures deposited by continental glaciation. Glacial till creates moderate-permeability conditions that are suitable for in-situ PRB installation, with enough groundwater flow to transport contaminants through the reactive barrier but low enough permeability to maintain amendment residence time.

The dual-contaminant challenge at this site — both VOCs (PCE) and metals (lead, selenium) — requires an amendment formulation that can address both contaminant classes simultaneously. The ZVI + Provect-IRM combination is uniquely suited for this challenge: ZVI provides both abiotic VOC treatment and metal immobilization, while the organic substrate component sustains the anaerobic conditions needed for both reductive dechlorination and metal sulfide precipitation. The lead reduction to below detection limits and selenium reduction (MW-16: 430 to 40 µg/L) demonstrate the effectiveness of this dual-treatment approach in glacial till hydrogeology.