1. LIMESTONE ROAD: REMEDIATION OF CHROMIUM CONTAMINATION IN A LANDFILLED SUPERFUND SITE NEAR CUMBERLAND, MARYLAND.

2. Introduction  Limestone Road Superfund Site(EPA ID: MDD980691588)  Two Adjacent Properties: Diggs Sanitation Company (Diggs)& Cumberland Cement and Supply Company (CCSC)  Sites on both Properties were used to Dispose of Industrial, Commercial, and Residential Waste  110 Tons of Chromium-Containing Sludge was Dumped on the Site  Mitre Model Hazard Ranking 30.54

3. Contaminated Area

4. Site History:  1960’s & 70’s: Both Sites used as Dumps for Commercial, Industrial, and Residential Waste (Including Construction and Demolition Debris)  April 1981 : 110 Tons of Chromium-Contaminated Sludge Dumped: CCSC Property (99 Tons) & Diggs’ Property (11Tons)  June 1981 : State of MD Issues a Complaint and Cleanup Order to both Parties (Challenged and Overturned in State Court)  March 1982 : EPA Conducts Preliminary Assessment  September 1986 : EPA Issues Operational Unit 1 (OU1) Record of Decision (ROD)  June 1996 : EPA Issues OU2 ROD

5. Overview of Chromium  Atomic Element #24 (Atomic Weight 51.996)  Exists in Oxidation States from +6 to -2  Cr(III) and Cr(VI) most commonly found in environment  Cr(III) is an Essential Trace Nutrient  Comparatively Immobile in Soils  Cr(VI) is a Known Carcinogen  Highly Mobile in Soils

6. Overview of Chromium (cont.)  Used in Many Industrial Processes  Steel  Dye/Pigment  Wood Preservatives  Leather  Cement Periodictable.com

7. Initial EPA Findings:  Maximum Total Chromium Soil Concentration Found:  97,600 ppm (mg/Kg)  Soil Cleanup Standards  Cr(III) – 120,000 ppm  Cr(VI) -0.3 ppm

8. Initial EPA Findings (cont.):  Other Contaminants Found at the Limestone Road Site were:  Zinc  Lead  Manganese  Barium  Arsenic  Cyanide  PAH’s  PCB’s  TCE

9. Chromium Remediation:  Three General Methods of Cr Remediation:  Removal  Containment  Detoxification

10. Removal:  Extraction Methods:  Site Excavation  Phytoextraction (i.e. with Portulaca oleracea)

11. Removal (cont.)  Separation Methods:  Ex-Situ Technologies  Membrane Filtration  Ion Exchange  Granular Activated Carbon (or other Adsorbents)  Soil Washing  In-Situ Technologies  Soil Flushing  Electrokinetics

12. Containment:  Immobilization: Reduction of Cr(VI) to Less Mobile Cr(III)  Chemical Reduction Fe(II), Fe(0) or S used as Electron Donors  Biological Reduction of Cr(VI) to Cr(III)  Psuedomonas, Micrococcus, Enterobacer and other Microbes  Isolation  Barrier with Low Permeability (Clay Soil Cap)

13. Detoxification:  Reduction of Cr(VI) to Cr(III) is a Detoxification Reaction  Chemical Reduction Fe(II), Fe(0) or S used as Electron Donors  Biological Reduction of Cr(VI) to Cr(III)  Psuedomonas, Micrococcus, Enterobacer and other Microbes

14. Remediation Actions Taken:  Multi-Layer Soil Cap of Low-Permeability Clays Placed over Affected Areas  Surface, Groundwater and Sediment Monitoring Stations  Properties were Fenced to Preclude Exposure to Public  Properties Deeds were Altered to Prevent Disruption of Soil Caps  PRPs were Ordered to Construct Municipal Water Lines for 19 Residents

15. Sampling Points:

16. Effect of Remediation Actions:

17. Effects of RA on other Contaminants:  As of the Second Five Year Review, all Contaminants of Concern at the Limestone Road Site met Drinking Water Protection Standards  Only Two Issues were Reported:  1. Two Residents have had Their Public Water Turned Off  EPA to Determine Cause of Water being Turned Off and if Residents are Using Wells, Collect a Sample from each Well on Site and Test for COCs  2. Replace Damaged/Missing Signs along the Edge of Fenced Site

18. Cost of Project: > $2 M  OU1: $1.2 M  Soil Capping  Fencing  Deed Alterations  Monitoring  OU2: $ 873,000  Municipal Water to 19 Residents

19. Cost Effectiveness:  Alternative to OU1:  Excavation of Contaminated Soils  Slight Cost Savings over Capping (not used due to Increased Exposure Potential During Site Excavation)  Alternatives to OU2:  Home Treatment Systems  Slight Cost Savings; However Decreased Reliability of Safe Drinking Water  Pump and Treat w/ Waterline  Over 4x the Cost of Waterline Alone  Fractured Bedrock Provide Difficulties for Effective Groundwater Treatment

20. Conclusions:  Soil Caps Have Been Affective in Isolating the Contaminants from the Groundwater  All Residents Have Access to Municipal Water; Most are Utilizing it  Physical and Legal Barriers have been put into Place to Minimize the Likelihood of Further Public Exposure

21. References Chatterjee, S., et al., 2007. “Sequestration and Localization of Metals in Two Common Wetland Plants at the Contaminated East Calcutta Wetlands, a Ramsar site in India.” Land Contamination & Reclaimation 15 (4):437-452. Dhal, B., et al., 2013. “Chemical and microbial remediation of hexavalent chromium form contaminated soil and mining/metallurgical soild waste: a review.” Journal of Hazardous Materials, 250- 251:272-291. Hawley, Elizebeth L., et al. Chromium (VI) Handbook. CRC Press, 2004. Print. McLean, J. S. and Beveridge, T. J., 1999. “Chromate removal from contaminated groundwater using indigenous bacteria.” Bioremediation of Metals and Inorganic Compounds, Fifth International In- Situ and On-Site Bioremediation Symposium, San Diego, CA. Battelle Press. Murray, K. J. and Tebo, B. M., 2007. Cr(III) is indirectly oxidized by the Mn(II) oxidizing bacterium Bacillus sp. Strain SG-1. Enviornmental Science Technology. 41(2):528-533. U.S. Center for Disease Control and Prevention (CDC). “Hexavalent Chromium.” Web. 6 November 2014. Web. http://www.cdc.gov/niosh/topics/hexchrom/.http://www.cdc.gov/niosh/topics/hexchrom/ U.S. Climate Data, 2014. “Climate-Cumberland, Maryland.” Web. 4 November 2014. http://www.usclimatedata.com/climate/cumberland/maryland/united-states/usmd0115.http://www.usclimatedata.com/climate/cumberland/maryland/united-states/usmd0115 U.S. Environmental Protection Agency (USEPA), 1986. Record of Decision: Limestone Road, EPA ID: MDD980691588, OU01, Cumberland, MD, 09/30/1986. PDF File. U.S. Environmental Protection Agency (USEPA), 1996. Record of Decision: Limestone Road, EPA ID: MDD980691588, OU02, Cumberland, MD, 06/28/1996. PDF File. U.S. Environmental Protection Agency (USEPA), 2011. Second Five-Year Review ReportforLimestone Road Superfund Site, Cumberland, Allegany County, Maryland, EPA ID: MDD980691588, January 2011. PDF file. U.S. Environmental Protection Agency (USEPA). “Integrated Risk Information System (IRIS): Chromium (VI) (CASRN 18540-29-9).” Web. 7 November 2014. http://www.epa.gov/iris/subst/0144.htm#oralrfd. http://www.epa.gov/iris/subst/0144.htm#oralrfd

22. Questions ?