Armen Cleaners Indoor Air Quality Investigation Jon Gulch, OSC U.S. EPA, Region V, ERB
Purpose of Investigation Assist MDCH in Evaluating Indoor Air Quality of Residences for the Presence of VOCs Associated with a Historical Release of PCE from a Dry Cleaning Facility
Physical Setting Operating Dry Cleaner Since Early 1950 s s in Residential Neighborhood Historical Releases to Subsurface Shallow Groundwater (<10 feet) Complex Geology (sands, silts, clays)
Situation Presumed Source Area Removed in 1980 s Shallow Soil Contamination GW Contaminated Indoor Air Sampling of Neighboring Residences
Project Challenges Limited Hydrogeological Data Available Shallow Groundwater Source for Vapor and Groundwater Contamination Still Present Complex Geology
Project Challenges (continued) Residences in Close Proximity (20 feet) to Dry Cleaner Armen Cleaners - Still Active
Historical Data
Historical Data (continued) Indoor Air of Residences Contaminated with VOCs? Background Source(s)? Ambient Air? Subsurface? Understanding of Hydrogeology at the Site? Existing Source Area(s)?
Historical Groundwater Flow
Goals of Investigation 1)Evaluate for the Presence of VOCs in Ambient Air and in Subsurface Structures
Goals of Investigation 2) Evaluate for the Presence of VOCs in Indoor Air of Nearby Residences
Goals of Investigation 3) Evaluate for the Presence of VOCs in the Subsurface (Unsaturated Zone)
Team Members U.S. EPA Region 5 Emergency Response Branch Grosse Ile, MI U.S. EPA Environmental Response Team (ERT) Edison, New Jersey Superfund Technical Assessment and Response Team (START) Region 5 Tetra Tech EM Inc.
Team Members (continued) Local, County, and State Agencies City of Ann Arbor Washtenaw County Department of Environmental Health Regulation Washtenaw County Department of Public Health
Team Members (continued) Local, County, and State Agencies (continued) Michigan Department of Environmental Quality Michigan Department of Community Health
The Site
Study Area 1 to 2 Block Radius Surrounding Armen Cleaners Residential and Subsurface Structures (manholes, utility boxes, etc.) 50 feet x 50 feet Grid Used Approximately 100 120 Sampling Locations
Investigation Overview Conduct Utility Survey Interview of Residents/Occupants Identification and Removal of Potential VOC Sources from each Residence Secure Access from Home Owners and Occupants Advance Geoprobe Soil Borings Membrane Interface Probe (MIP)
Investigation Overview (continued) Install Soil Gas Probes Based on MIP Data Basement of Residences within Plume Soil Gas Sample Collection and Analysis Indoor Air Sampling-U.S. EPA-ERT ERT TAGA Screen Residences for VOC Sources and Have Any Remaining Removed
Investigation Overview (continued) Indoor Air Sampling (continued) Collect and Analyze Air Samples (Summa and Real Time using U.S. EPA-ERT ERT TAGA) Basement Soil Gas Probes Outdoor Air Sampling Exterior of Residences Underground Structures Plot Data
Investigation Overview (continued) Scope Allowed a Unique Snapshot of the Full Vapor Intrusion Pathway Soil/GW to Soil Vapor to Sub-slab to Indoor Air to Ambient Air Use of Real-Time Data Collection Techniques and Triad Approach Results Driven
Resident/Occupant Interviews Door to Door Interviews and/or at a Public Meeting Standardized Form Help Identify Background VOC Sources Direct Occupants to Remove any Potential Sources of VOCs
Access Agreements Door to Door Interviews and/or at a Public Meeting Locate Utilities/Underground Structures on Private Property Answer Questions About Upcoming Field Work Combined with Occupant Interviews
Soil Borings - Direct Push Methodology Begin at Source Dry Cleaner Membrane Interface Probe (MIP) Define Vertical and Horizontal Limits of Plume Conducted Prior to U.S. EPA-ERT ERT TAGA Unit On-Site
Membrane Interphase Probe
MIP Continuous Real-Time Vertical Profiling of Subsurface Identify Extent of Plume Including Zones of Contamination and Migration Pathways Data Utilized to Generate 3-D 3 D Maps Assist in Determining Soil Gas Probe Locations and Depths
MIP Advancement
Soil Gas Probe Installation Semi-Permanent; i.e. MDEQ will Utilize Soil Gas Probes During Subsequent Remedial Activities Locations Based on MIP Data Allow Monitoring of Contaminant Plume and Quantification of Soil Gas Concentrations
Soil Gas Probe Installation (continued) Assist in Evaluation of Indoor Air Intrusion Pathways Installed by Hand
Soil Gas Probe
Collection of Soil Gas Samples Samples Collected by START Using Tedlar Bags Analyzed in the Field Using U.S. EPA- ERT TAGA Unit Data Plotted on GIS Data Base as it is Generated
Sampling of Soil Gas Probes
Trace Atmospheric Gas Analyzer (TAGA)
U.S. EPA-ERT TAGA
Indoor Air Sampling Screen House Using U.S. EPA-ERT ERT TAGA Summa Canisters - (24-Hour) 2 Per Residence Basement Probes (sub-slab) slab) only those houses within plume
SUMMA Canister Sampling
Outdoor Air Ambient Air SUMMA Canisters and TAGA Adjacent to Houses Basement First Floor
SUMMA Canister Sampling
TAGA Sampling
Plot Data Surveyed Using Global Positioning System (GPS) U.S. EPA and Previous Data (MDEQ) will be Included Real-time Updates on Database During Investigation
Plot Data (continued) Plotted Using Geographic Information System ArcMap Final Database Provided to Task Force Members in Electronic Form
Final Report Site Has Been Selected by TIO as a Case Study Detailed Report is Currently Being Developed MDCH is Preparing a Health Consultation for the Site Final GIS Database Will Include all of Data Collected to Date Includes (Analytical, GPS, MIP, TAGA)
Preliminary Findings Source Area Still Believed to be Present in Subsurface Around Dry Cleaners PCE in Excess of Soil Saturation Concentration Believed to be Present Good Correlation of MIP Data to Soil Vapor Concentrations
Armen Cleaners - CSM
MIP Log - Source
ECD Detector
PID Detector
Soil Vapor Plume
Ambient Air Results
Results Summary
Preliminary Findings (continued) PCE Identified in Indoor Air of the Houses Around Dry Cleaner Background VOCs Still Detected in Indoor Air Samples
Background VOCs Acetone (4.4 82 ppbv) Ethanol (5.4 210 ppbv) 2-propanol (4.7 7.8 ppbv) Freon 11 (1.1 ppbv) Freon 12 (0.68 ppbv) Chloromethane (0.91 ppbv) Methylene Chloride (0.9 ppbv)
Background VOCs (continued) Toluene (1.2 34 ppbv) M,p Xylene (0.67 1.7 ppbv) 2 Butanone (3.9 6 ppbv)
Status of the Project Field Work Completed Case Study Report Draft to be Completed November 2004 (draft) Data Entered into GIS Database Final Products Anticipated to be Completed Fall 2004 EPA - TIO (BTSC) Web Site Will Have Electronic Version of report
Additional Information Jon Gulch - U.S. EPA 734-692 692-7686 gulch.jon jon@epa.gov David Sawicki Tetra Tech EM Inc. 248-350 350-9694 david.sawicki sawicki@ttemi.com
Questions?