1. AHMET UCANOK JOHN E. ELVIS Pump and Treat of Contaminated Groundwater at the United Chrome Superfund Site Corvallis, Oregon

2. Site Description and History In 1956, a disposal pit for liquid waste was dug and plating tanks were located near the disposal pit. Chromium-laden wastewater was discharged to the pit from 1956 to 1982. Sludges were removed from the pit in 1982. In June 1983, United States Environmental Protection Agency (“EPA”) discovered chromium contamination in on-site surface water and soils. EPA performed contaminated soil removal activities at the site in 1985. An on-site surface drainage ditch was dammed and rerouted as part of remedial activities in 1988. Groundwater contamination was addressed in two phases. Phase I began in August 1988 and Phase II began in September 1991.

3. Problem Description SOURCES OF GROUNDWATER CONTAMINATION Leakage Poor storage Improper disposal Ore processing Cr 6- Hexavalent chromium

4. Problem Description IMPACTS OF CONTAMINATION Environmental impacts Chromium contaminated soil Chromium contaminated surface water Chromium contaminated groundwater Health impacts Kidney and liver damage Teeth degradation Any type of cancer

5. Problem Description REMEDIAL INVESTIGATION AND FEASIBILITY STUDY Contamination in the Soil: Magnitude of contamination and the distribution of contaminants in onsite soils

6. Problem Description REMEDIAL INVESTIGATION AND FEASIBILITY STUDY Contamination in the Water: Technical aquifer information and magnitude of contamination in aquifers.

7. Problem Description REMEDIAL INVESTIGATION AND FEASIBILITY STUDY Plume Water Boundary: Chromium Contaminant Plumes in the Upper and Deep Aquifers Prior to August 1988

8. Possible Solution (Land Remediation) OBJECTIVES Reduce amount of toxic Reduce volume of waste generated. Conserving soil and water. Return Land to beneficial use

9. Remediation Approach 1.ISOLATION Capping Insitu Barrier Diversion Trenches 2.REMOVAL Excavation Soil washing 3.TOXICITY/ MOBILITY REDUCTION Chemical Treatment Permeable Treatment walls 4.EXTRACTION WELLS Pumping and Treatment

10. REMEDIATION APPROACH 1 1 2 2 3 3 4 4

11. Adopted Solution In 2000, the City of Corvallis removed approximately 1,000 cubic yards of chromium-contaminated soil from the site and transported to the Chemical Waste Management facility in Arlington, Oregon. A.EXCAVATION AND DISPOSAL OF CONTAMINATED SOIL

12. B.EXTRACTION METHOD (PUMP AND TREATMENT)  in 1988, 23 extraction wells installed on upper zone and 7 on deep aquifer to remove the contaminated groundwater.  Remove of the contaminant from the two zones has resulted in a significant reduction in the magnitude and size of the chromium plume

13. CONCLUSION Finally, installation of addition extraction wells performed by pumping and treatment in upper and deep aquifer zones has been succeeded by remove all contaminant chromium. Contaminant plume have been reduce to a small size.Hence the Project succeeded  In health and environnemental protection.  To meet clean up standard for protection of lower aquifer,used for drinking water.