Chemical Metals Industries, Inc. (CMI) Vapor Intrusion Issues at the First Removal Action Site Site #1 Site #2

Agenda Background Environmental Issues Current Activities Soil and Groundwater Contamination Vapor Intrusion Current Activities MDE Actions Site #2 (2103 Annapolis Road) 2000 Block of Annapolis Road Homes) EPA Actions at Site #1 (2001 Annapolis Road)

Background 1981 - First Removal Action in US 1997 to Present – Post Removal Investigations Soil Investigations / Removal Groundwater Investigations Vapor Intrusion investigations 1950s-1973: The properties at 2001 and 2103 Annapolis Road (“the Properties”) are used for commercial purposes including a gasoline service station and a precious metals refining business. April 1973: Chemical Metals Industries (“CMI”) incorporates and some time after begins a metals recovery and copper sulfate manufacturing operation on the Properties. October 19, 1981-December 18, 1981: EPA declares the Properties a Superfund site and performs an Emergency Removal Action along with a team of federal, State and local agencies. Various tanks, containers, at least 1500 deteriorated drums, and approximately 21,000 gallons and 114,000 pounds of hazardous waste are removed from the Properties. Underground storage tanks are removed or abandoned in-place and building decontamination activities are performed. Nine monitoring wells are installed on the Properties to evaluate groundwater and soil quality. Soil and groundwater sampling results indicate significant contamination by various metals and volatile organic compounds (VOCs). Based on these findings, 2001 Annapolis Road property is covered with a foot of clayey fill material and outdoor areas of 2013 Annapolis Road property is covered with a layer of asphalt paving.

Site #2 – 2103 Annapolis Road Assessment Activities Monitoring wells installed to determine extent of subsurface contamination.

Remediation Activities Site #2 - 2103 Annapolis Road Soil Vapor Extraction System Injections of Chemical Oxidation Subslab depressurization system at 2103 Annapolis Road (CMI Site #2). A sub-slab depressurization system basically consists of a fan or blower which draws air from the soil beneath a building and discharges it to the atmosphere through a series of collection and discharge pipes. One or more holes are cut through the building slab so that the extraction pipe(s) can be placed in contact with subgrade materials, in order for soil gas to be drawn in from just beneath the slab. In

Remediation Activities (Cont’d)

Indoor Air Sampling

Vapor Intrusion Issues 2009 2011 2013 2015 2017 2019 2021 2023 2025 2027 2029 2031 2033 2035 2037 2039 2041 2043 2045 2047 Owner Occupied CMI Site #1 Plume CMI Site #2 34 PCE 3.7 TCE 0.089J VC Soil Gas: 350,000 PCE 20,000 TCE 800 VC 19 PCE 1.7 TCE 31/30 PCE 410 PCE 71 TCE 1000 PCE 540 TCE 4800 PCE 4900 TCE 1.4 PCE 0.38 TCE 3.0 PCE 1.6 TCE 2.1 PCE 3.6 TCE 2.2 PCE 0.55TCE 9.0 PCE 10.0 TCE 0.068 VC 3.1 PCE 2.8 TCE 3.4 PCE 0.11 VC 21 PCE 1.8 TCE 16 PCE MDE collected soil, groundwater, soil gas and indoor air samples in a step-wise fashion (1) Collected soil and groundwater samples; (2) collected soil gas and subslab soil gas samples around houses; (3) collected indoor air samples. Based on sample results, MDE began planning remedial measures to address long-term risk for properties located at 2009, 2011, 2013, and 2047 Annapolis Road. Sept/Oct 08 Update: For 2011, PCE and TCE was 86 ug/m3 and 9.03 ug/m3 in the basement and 27.9 ug/m3 and 5.97 ug/m3 on the first floor (living space), respectively; For 2013, PCE was 23.6 ug/m3 in the basement and 6.17 ug/m3 and 12.5 ug/m3 on the first floor (front and back of first floor). Site-specific conceptual model Building construction & current condition Modeling based on groundwater data Johnson & Ettinger screening model Sampling Soil gas sampling Indoor air sampling Difficulties with Gaining Site Access: Owner Occupied Versus Rental Properties Frequent Changes In Property Ownership Land-lord/Tenant Issues Delays In Site Access

Design Challenges for Vapor Intrusion Mitigation Systems 1920s Row Houses Stacked Stone Foundation Dirt Floors And/Or Broken Concrete Floors Adequate Electrical Supply Site #1 MDE evaluated the properties affected by vapor intrusion and have installed a subslab depressurization system in one house. The other two houses will have basement ventilation systems installed. These systems consist of low suction, high volume fan that vents basement air to the outside while maintaining a negative pressure in the basement space. Site #2

Summary Site #1 Site #2 MDE To Monitor Effectiveness Of Remedy MDE To Provide Assistance As Needed By EPA Site #2 MDE To Monitor Effectiveness Of Remedy Inspect Operation Of Vapor Mitigation Systems

For Further Information: Controlled Hazardous Substance (CHS) Enforcement Division Land Restoration Program Land Management Administration Maryland Department of the Environment 1800 Washington Boulevard, Suite 625 Baltimore MD 21230 (410) 537-3437 http://www.mde.state.md.us/Programs/LandPrograms/ERRP_Brownfields/ERRP_Superfund/index.asp