Vapor Intrusion Field Methods and Recent Results from EPA Funded Research

Transcription

1 Vapor Intrusion Field Methods and Recent Results from EPA Funded Research Georgia Environmental Conference August 21, 2013 Jekyll Island, Georgia Jim Fineis P.G. Atlas Geo-Sampling Company

2 Vapor Intrusion Field Methods Soil Vapor Sample Type: Near Source Near Slab Sub-Slab 3-Dimensional Profiling (all the above) Leak Test Method Active Leak Test (Helium or other gases) Passive (IPA, Shaving Cream, 1,1,DFA) Slab Specific Attenuation Calculations How? Why?

3 Where to Collect Your Soil Vapor Sample? What is the Purpose of Your Sample? Are Your Soil Vapor Levels a Risk to Occupants of the Building? Determine the Source of Your Vapor Issue? Evaluate the Current Building or a Future Building Sub-slab Vapor Samples are the Preferred Sample Type to Determine Risk to Occupants 3 Dimension Vapor Sampling is Required to Determine the Source of Your Vapor Issue (Groundwater Source, Soil Source, Indoor Air Source) Sometime the Type of Sample You Can Collect is Determined by Other Factors Access to the Building is not Granted

4 Soil Vapor Sample Types Sub-slab Permanent Multi-Level Near Slab Temporary Sub-slab Temporary Multi-Level Thru DPT Rods

5 Soil Vapor Sampling Active Leak Test Methods Active Leak Test Methods Leak Test is Performed in the Field Prior Collecting the Soil Vapor Sample Helium Leak Test is Generally Considered the Gold Standard in Leak Test Current IRTC Guidance Allows for a 10% Leak Because Surface Material is Porous (Concrete, Asphalt, Grass) Some States Only Allow for a 5% Leak Check Your Local Regulations

6 Soil Vapor Leak Test Options Active Leak Test of Installed Implant Passive Leak Test of Installed Implant Shut In or Leak Test of Sampling Equipment The Sampling Equipment has the Highest Chance of Leaking Beware of the Hardware Used to Collect the Sample Project Completed Last Week: 65% of All Sample Kits Required Field Repair to Fix Leaks 38 of 58 Sample Kits Required Repair

7 Soil Vapor Sampling Passive Leak Test Options Passive Leak Test Compound is Applied to a Rag and Placed Around the Base of the Implant or DPT Rod. Common Compounds Are: 1,1,DFA IPA Shaving Cream (NOT Recommended See Upcoming Slide)

8 Do You Have to Accept the Default Attenuation Factor Once Sub-slab Data Is Collected? No! Current EPA Default Sub-slab Attenuation Factor is.1 Proposed New EPA Default Sub-Slab Attenuation Factor is.03 Calculate A Site Specific or Slab Specific Attenuation Factor - Below Are the Results of Two Such Recent Calculations: Metro Atlanta Site.0004 Augusta Georgia Site -.003

9 What is This Toxic Substance? Remember A Few Slides Back? CS2 = 140 ug/m3 Benzene = 389 ug/m3 TPH=680,000 ug/m3

10 Barbasol Shaving Cream Barbasol shaving cream: Benzene & TPH at levels 1000x above indoor air screening levels! If a Passive Leak Test is to be Conducted During Vapor Sampling Events Choose Your Leak Test Compound Wisely

11 Why is Indoor Air Sampling So Risky? But We Don t Use CHLORINATED Chemicals Anymore... Plastics: 1,2-DCA Gun Cleaner: TCE Pepper Spray: TCE Brake Cleaner: TCE/PCE Glue TCE

12 Want One More Example?

13 Ethanol ,4-Dioxane 2100 Benzene 19 Naphthalene 31

14 Recent Results From EPA Funded Research The Next Few Slides are the Results of Some Recently Released EPA Funded Research: Purge Rate Experiment Sample Volume Experiment Sample Tubing Type Comparison Soil Gas Equilibration Study Temporal Trends Study

15 Purge Rate Experiment TCE Concentration (µg/m³) 4,000 3,500 3,000 2,500 2,000 1,500 1, ,000 2,000 3,000 4,000 5,000 6,000 Purge Rate (ml/min) 15-SV-B1 15-SV-B2 15-SV-B3 15-SV-B4 15-SV-B5 " Slight positive correlation overall " Variability generally within analytical error

16 " Decrease in concentration at 6,000 ml (6-liter Summa) Sample Volume Experiment TCE Concentration (µg/m³) 4,000 3,500 3,000 2,500 2,000 1,500 1, ,000 2,000 3,000 4,000 5,000 6,000 7,000 Sample Volume (ml) 15-SV-A1 15-SV-B2 15-SV-B3 15-SV-C2 15-SV-C5 " Moderate positive correlation from 25 to 1,000 ml

17 Tubing Type Comparison TCE Concentration (µg/m 3 ) Nylaflow Teflon PEEK Stainless Steel Copper Polyethylene 26-Feb Feb Jun Nov Mar-09 " Polyethylene consistently low " Copper unacceptable soon after installation

18 Equilibration Time Buried Implants ~60% after 2 hrs, 70% after 4 hrs, 85% after 8 hrs

19 Temporal Trends Data collected over 12 months. Max variation: factor of 2 to 3 Heavy rains had little effect even in unpaved area!!

20 Temporal Trends

21 170 PCE - SSP- 4 (Port 13) Vapor Concentration (ug/m3) /5/2011 8/15/2011 8/25/2011 9/4/2011 9/14/2011 9/24/ /4/ /14/ /24/2011 Date & Time

22 2012/-2013 Data SSP- 2 PCE Significant Sub-Slab Variations do NOT Occur Over Short (weeks) Time Scale PCE /2012 1/2013 2/2013 3/2013

23 Questions? Jim Fineis P.G. Atlas Geo-Sampling Company Soil Vapor Sampling Is So Fun. Please Stop By Our Booth (#38) If You Have Any Questions