Solid Technology, Superior Value, Proven ResultsProject Case Study

Series

Treatment of a Mixed CVOC & Cr Contaminated Site Using In Situ Chemical Reduction (ISCR™)

and Stimulated Biotic Mineralization

Site: Former Manufactured Gas Site (Cleveland Flats) Cleveland, OH

Lead Consultant/Contractor:

Project Case Study: In Situ Chemical Reduction (ISCR™) and Stimulated Biotic Mineralization

AbstractThe implementation of efficient and cost-effective remedial solutions in the clean-up of impacted properties is paramount in returning brownfields and other impacted properties to viable use in the face of the recent real estate market declines. Historical site use of the Cleveland Flats project area included: a manufactured gas plant (circa. 1850), trucking terminal, & plating operations. As part of the overall project area remediation effort, sustainable and innovative in-situ remedial technologies were evaluated for use per proposed site redevelopment plans for the portion of the site formerly utilized for plating operations.

The soil and groundwater in this area of the Site was impacted by chlorinated organics as well as hot spot areas of elevated chromium. As a result of the remedial efforts, Voluntary Action Program (VAP) and Bureau of Underground Storage Tank Regulation (BUSTR) standards were met for the former plating operations area at the property by using the selected treatment technology of In-Situ Chemical Reduction (ISCR) and the associated post-ISCR performance monitoring. A combination of organic hydrogen donors, oxygen scavengers and iron was used to precipitate hexavalent chromium and reduce CVOC concentrations by stimulating biological activity capable of reductive dechlorination.

Aerial view of project site.

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ISCR Remediation • Designed & implemented to degrade

chlorinated organics & mineralize metals in groundwater

• TCE, cis-DCE, VC, and Cr • Exceedances to Aquatic Life Criteria (OMZA)

for Cuyahoga River • Groundwater impacts: ~ 8 to 15 ft-bgs • Total Treatment Area: ~7,000 ft2 • Area A: ~3,000 ft2 and Area B: ~4,000 ft2 • Completed using direct push injection • EHC-M® - Reductive Dechlorination • Sodium Sulfite – O2 scavenger • Calcium Propionate – Addn. H2 source • 8,400 gallons of ISCR amendments injected • 28,100 lbs. EHC-M ® • 420 lbs. of Sodium Sulfite • 2,100 lbs. of Calcium Propionate • Total of 70 injection locations completed in

Area A and Area B • Completed in 6 days (October 2009) • Costs - ~$300K (includes 6 rounds of

Performance Monitoring)

Observations and Conclusions • Achieved reducing geochemical conditions to

promote reductive dechlorination • DO < 1 mg/L • ORP at significantly negative values • pH: 6 to 8 (optimum range) • Groundwater temperature varied seasonally • DHE present in groundwater (one-time

event) • Observed increases in Fe+2 • Elevated TOC in Areas A&B - Effective

distribution of ISCR amendments • PM indicates chlorinated VOCs below

Aquatic Criteria • VOC progression from parent product

through daughter products to end products (i.e., ethene)

• Average Concentration Reduction - 90% • Cost Savings - ~$300K (ISCR vs Excavation) • Use of ISCR Green & Sustainable compared

to other evaluated remedial approaches (i.e., P&T, Excavation, ISCO)

Project Case Study: In Situ Chemical Reduction (ISCR™) and Stimulated Biotic Mineralization 4

Performance Monitoring • 6 monitoring wells – 3 per Area • 6 rounds of sampling (Baseline & 5 post

ISCR events) • Baseline – Sept. 2009 • Round 1 – Oct. 2009 • Round 2 – Nov. 2009 • Round 3 – Dec. 2009 • Round 4 – Feb. 2010

• Round 5 – May 2010 • Parameters • Geochemistry (DO, ORP, pH, Temp,

Conductivity, Fe+2) • VOCs (TCE, cis-DCE, VC) • Dissolved gases (methane, ethane, ethene) • Metals (Cr) • Inorganics (nitrate, sulfate, chloride) • Compared to Aquatic Life Criteria

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Project Case Study: In Situ Chemical Reduction (ISCR™) and Stimulated Biotic Mineralization 6

The Adventus Group provides a growing portfolio of leading environmental remediation technologies, including patented products, and is best known for leadership in the area of in situ chemical reduction (ISCR) with the EHC® family of products. Adventus pioneered ISCR in the early 90’s to effectively and economically treat soil and groundwater contaminated with a wide variety of organic constituents and/or metals amenable to biological and chemical reduction. Other Adventus products are also used to address problems that require oxidation processes and contaminant flux management. We support site owners, consultants, regulators, and others by providing unbiased design, and selection of the most cost-effective remediation strategies. Adventus has a world-wide presence and a strong record of sharing its achievements across more than 500 technical abstracts and publications.

The Adventus Group provides the environmental remediation

industry with a portfolio of innovative proprietary Soil,

Sediment, and Groundwater remediation solutions and

other technologies shown here. Contact us today to arrange a

complementary Technology Transfer Session, or Site

Evaluation.

Contact InformationDoug Gray, Innovative RemedialTechnologies Group ManagerURS Corporation – Cleveland Office1375 Euclid Avenue, Suite 600 Cleveland, OH 44115 Phone: 216.622.2283E-mail: doug_gray@urscorp.com

www.AdventusGroup.com7

Solid Technology, Superior Value, Proven Results