Indoor Air Quality Sampling And Evaluation

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Indoor Air Quality Sampling and Evaluation: "MADEP’s Proposed Guidance and What it Means to LSPs"
Presented By:

Dammon M. Frecker
Vice President, Industrial Compliance and Permitting
Environmental Science Services, Inc.

and

Peter W. Woodman, Ph.D.
President
Risk Management Incorporated


Licensed Site Professionals Association Meeting - May 15, 2001

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Indoor Air Quality Sampling And Evaluation

  1. 1. Indoor Air Quality Sampling and Evaluation: MADEP’s Proposed Guidance and What it Means to LSPs Presented By: Dammon M. Frecker Vice President, Industrial Compliance and Permitting Environmental Science Services, Inc. and Peter W. Woodman, Ph.D. President Risk Management Incorporated Licensed Site Professionals Association Meeting May 15, 2001
  2. 2. Overview <ul><li>Part I – Air Quality Measurements </li></ul><ul><ul><li>Planning the Study </li></ul></ul><ul><ul><li>Air Sampling Methods </li></ul></ul><ul><ul><li>QA/QC Considerations </li></ul></ul><ul><li>Part II – Analysis of Data </li></ul><ul><ul><li>Data Evaluation </li></ul></ul><ul><ul><li>Health Risk Assessments </li></ul></ul>
  3. 3. Planning the Study <ul><li>Define Objectives </li></ul><ul><li>Pre-Sampling Investigations </li></ul><ul><li>Determine Study Parameters </li></ul><ul><li>Select Appropriate Method(s) </li></ul>
  4. 4. Defining Objectives <ul><li>Are we trying to determine: </li></ul><ul><ul><li>What is in the air? </li></ul></ul><ul><ul><li>How much is in the air? </li></ul></ul><ul><ul><li>Where is it in the air? </li></ul></ul><ul><ul><li>Is anyone adversely exposed? </li></ul></ul><ul><li>Is the concern acute or chronic exposure? </li></ul><ul><li>Answers to these questions guide method selection. </li></ul>
  5. 5. Pre-Sampling Investigation <ul><li>Nature, location and extent of subsurface contamination </li></ul><ul><li>Nature and concentration of contaminants </li></ul><ul><li>Meteorology </li></ul><ul><li>Setting (i.e.residential vs. industrial) </li></ul><ul><li>Other contaminant sources </li></ul>
  6. 6. Other Sources of Contaminants <ul><li>Outdoor sources </li></ul><ul><ul><li>Nearby facilities </li></ul></ul><ul><ul><li>Mobile sources </li></ul></ul><ul><li>Indoor sources </li></ul><ul><ul><li>Household Chemicals/Personal Care Products </li></ul></ul><ul><ul><li>New Building Materials </li></ul></ul><ul><ul><li>Smokers </li></ul></ul><ul><ul><li>Heating systems </li></ul></ul><ul><li>See Example Survey in Appendix 2a </li></ul>
  7. 7. Study Parameters <ul><li>Sampling Conditions – Typical vs. Worst Case </li></ul><ul><ul><li>Ambient temperature </li></ul></ul><ul><ul><li>Wind </li></ul></ul><ul><ul><li>Precipitation </li></ul></ul><ul><ul><li>Groundwater levels </li></ul></ul><ul><ul><li>Ventilation </li></ul></ul><ul><ul><li>Activities </li></ul></ul>
  8. 8. Instructions to Residents <ul><li>The list of “do nots”(at least 48 hrs prior): </li></ul><ul><ul><li>Operate ventilation equipment </li></ul></ul><ul><ul><li>Keep doors, windows, vents or fireplace open </li></ul></ul><ul><ul><li>Use air fresheners, cleaning products or personal care products </li></ul></ul><ul><ul><li>Use paints, varnishes, pesticides </li></ul></ul><ul><ul><li>Smoke </li></ul></ul><ul><ul><li>Store chemicals </li></ul></ul>
  9. 9. Where to Sample <ul><li>“ Representative” Sampling </li></ul><ul><ul><li>Weighted average of living spaces </li></ul></ul><ul><li>“ Worst Case” Sampling </li></ul><ul><ul><li>Closest to suspect source </li></ul></ul><ul><li>Generally, both are recommended </li></ul><ul><li>Consider spatial gradient sampling </li></ul><ul><li>Locate samplers in breathing zone </li></ul><ul><li>Consider air circulation patterns, ventilation, cellar door </li></ul>
  10. 10. Sampling Duration <ul><li>Short term sampling – Long term forecasts </li></ul><ul><li>Need to consider: </li></ul><ul><ul><li>Duration of exposure </li></ul></ul><ul><ul><li>Variability of contaminant source </li></ul></ul><ul><ul><li>Timing of routine activities </li></ul></ul><ul><ul><li>Limitations of sampling methods </li></ul></ul><ul><li>Generally, longer is better (“several” to 24 hrs) </li></ul>
  11. 11. Recommended Sampling Durations X X X Subchronic X X X Chronic X X Acute Seasonal Repeated ~3 Weeks 2-24-Hour Grab
  12. 12. How Many Samples? <ul><li>Living area(s) and “worst case” area </li></ul><ul><li>Statistical validity </li></ul><ul><li>QA/QC </li></ul><ul><ul><li>Co-located samplers </li></ul></ul><ul><ul><li>Repeats </li></ul></ul><ul><ul><li>Blanks </li></ul></ul>
  13. 13. Over-Sampling Strategy <ul><li>Collect numerous samples with optional analysis </li></ul><ul><ul><li>Time weighted sampling for sub-chronic exposure evaluation </li></ul></ul><ul><ul><li>Longer term samples (badges?) to evaluate chronic exposure </li></ul></ul><ul><li>Example: </li></ul><ul><ul><li>Triplicate passive samplers in basement, living room, bedroom, and/or other area </li></ul></ul><ul><ul><li>Collect 10 % “blanks” </li></ul></ul><ul><ul><li>Analyze 2 of each set immediately </li></ul></ul><ul><ul><li>Analyze third if variation >15% </li></ul></ul>
  14. 14. Over-Sampling Strategy <ul><li>Collect TWA samples using canisters or tubes </li></ul><ul><li>Collect charcoal badge samplers at canister locations for 3-4 weeks </li></ul><ul><li>Analyze TWA samples </li></ul><ul><li>Analyze badge samples if TWA results are “high” </li></ul>
  15. 15. Sampling/Analytical Limitations <ul><li>“Detection” Limits </li></ul><ul><ul><li>Instrument/Method Detection Limits (MDL) </li></ul></ul><ul><ul><li>Practical Quantitation Limit (PQL) </li></ul></ul><ul><li>Maximum Sample Volume </li></ul><ul><ul><li>Saturation Breakthrough </li></ul></ul><ul><ul><li>Migration Breakthrough </li></ul></ul><ul><li>Work with your analytical laboratory!! </li></ul>
  16. 16. Sampling Methods <ul><li>Analytical Methods </li></ul><ul><ul><li>Provide real time results </li></ul></ul><ul><ul><li>PID, FID, On-Site GC, mini-RAM, other </li></ul></ul><ul><ul><li>Good application for some ambient gases (CO 2 ) </li></ul></ul><ul><li>Collection Methods </li></ul><ul><ul><li>Canisters, tubes, badges, filters </li></ul></ul><ul><ul><li>Provide lower detection limits </li></ul></ul>
  17. 17. Sorbent Collection Methods <ul><li>Methods can be found at: http://www.epa.gov/ttn/amtic/airtox.html </li></ul><ul><li>TO-1: </li></ul><ul><ul><li>Tenax adsorption, thermal desorption, GC/MS analysis </li></ul></ul><ul><ul><li>Volatile, non-polar organics w/ BP 80-200’C (but not all!) </li></ul></ul><ul><ul><li>50-500 cc/min sample rate, BT volumes 20-200l/g, IDL 5-20ng </li></ul></ul><ul><ul><li>Backup tubes and duplicates recommended </li></ul></ul><ul><ul><li>Proper Tenax prep and sample handling </li></ul></ul><ul><li>TO-2: </li></ul><ul><ul><li>Carbon molecular sieve adsorption, thermal desorp, GC/MS </li></ul></ul><ul><ul><li>Volatile, non-polar organics w/ BP -15-120’C (but not all!) </li></ul></ul><ul><ul><li>Similar considerations to TO-1 </li></ul></ul>
  18. 18. Sorbent Collection Methods <ul><li>TO-10A: </li></ul><ul><ul><li>Polyurethane foam (PUF), solvent extraction, GC/MS (or multi-detector) (or HPLC/UV) </li></ul></ul><ul><ul><li>Pesticides and PCBs </li></ul></ul><ul><ul><li>4-24 hr sample duration, 0.0001-50 ug/M 3 detection </li></ul></ul><ul><li>TO-17: </li></ul><ul><ul><li>Multi-sorbent sampler, thermal desorption, GC/MS </li></ul></ul><ul><ul><li>Wide variety of organic compounds (sorbent dependant) </li></ul></ul><ul><ul><li>5-200 ml/min sample rate, 1-4L total sample size </li></ul></ul>
  19. 19. Canister Collection Methods <ul><li>Specially lined and prepared canisters </li></ul><ul><li>Unattended vacuum collection, 2-24 hours </li></ul><ul><li>EPA Methods TO-14A and TO-15 </li></ul><ul><li>MADEP “APH” Method </li></ul>
  20. 20. Quality Assurance & Control <ul><li>QA: Management activities that assure results are of known and documented quality </li></ul><ul><li>QC: Technical activities that measure how well QA objectives are met. </li></ul><ul><li>Holistic vs. fractionated approach </li></ul><ul><li>Involve everyone!! </li></ul>
  21. 21. Data Quality Objectives <ul><li>Precision: </li></ul><ul><ul><li>Measure of variability </li></ul></ul><ul><ul><li>Determined by duplicates </li></ul></ul><ul><ul><li>Most important as results approach MDL </li></ul></ul><ul><li>Accuracy: </li></ul><ul><ul><li>Measure of deviation from true value </li></ul></ul><ul><ul><li>Determined by field/trip blanks, audit samples </li></ul></ul>
  22. 22. Data Quality Objectives <ul><li>Representativeness </li></ul><ul><ul><li>“ Did we take the samples in the right place?” </li></ul></ul><ul><ul><li>Truly representative of exposures </li></ul></ul><ul><li>Completeness </li></ul><ul><li>“ Is there enough data to make a decision?” </li></ul>
  23. 23. Recommended QC Measures <ul><li>Sampling </li></ul><ul><ul><li>At least one set of replicate samples (+/-25%) </li></ul></ul><ul><ul><li>At least one field blank </li></ul></ul><ul><ul><li>Consider series sampling for tubes </li></ul></ul><ul><li>Analysis </li></ul><ul><ul><li>Consider MDLs </li></ul></ul><ul><ul><li>Method & instrument blanks </li></ul></ul><ul><ul><li>Instrument calibration range </li></ul></ul><ul><ul><li>Matrix spikes ad duplicates </li></ul></ul><ul><ul><li>Audit samples </li></ul></ul>
  24. 24. Summary/Recommendations <ul><li>Approach should be aligned with objectives </li></ul><ul><ul><li>“ You got to be careful if you don't know where you're going, because you might not get there.” (Y. Berra) </li></ul></ul><ul><li>Importance of upfront planning </li></ul><ul><ul><li>“ Proper Planning Precludes Poor Performance!” </li></ul></ul><ul><li>Consider applicability and limitations of methods </li></ul><ul><ul><li>&quot; It isn't pollution that is hurting the environment, it's the impurities in our air and water that are doing it.&quot; (D. Quayle) </li></ul></ul><ul><li>Attention to QA/QC is critical </li></ul><ul><ul><li>“ If there is a 50-50 chance that something can go wrong, then 9 times out of ten it will.” (P. Harvey) </li></ul></ul>
  25. 25. PART TWO Evaluation of Sampling Results <ul><li>Peter W.Woodman, Ph.D. </li></ul><ul><li>President </li></ul><ul><li>Risk Management Incorporated </li></ul>
  26. 26. Evaluation of Sampling Results <ul><li>Source - Known or Unknown </li></ul><ul><ul><li>Fate and transport considerations </li></ul></ul><ul><li>Soil Gas and Indoor Air Sampling </li></ul><ul><ul><li>Background Screening </li></ul></ul><ul><li>Critical Exposure Pathway </li></ul><ul><li>(310 CMR 40.006 and 40.0414(3)) </li></ul><ul><li>Substantial Release Migration </li></ul><ul><li>(310 CMR 40.006 and 40.0414(3)) </li></ul>
  27. 27. Evaluation of Sampling Results <ul><li>Risk Assessment </li></ul><ul><ul><li>Allowable Threshold Concentrations </li></ul></ul><ul><ul><li>Imminent Hazard </li></ul></ul><ul><ul><li>Substantial Hazard </li></ul></ul><ul><ul><li>Significant Risk </li></ul></ul><ul><li>MCP Response Actions </li></ul>
  28. 29. Fate & Transport Considerations CONTAMINATED SOIL GROUNDWATER KNOWN SOURCES HOUSEHOLD PRODUCTS AMBIENT/ INDOOR AIR DRINKING WATER VOLATILES UNKNOWN SOURCES
  29. 30. Background Screening <ul><ul><li>Petroleum </li></ul></ul><ul><ul><li>Products </li></ul></ul><ul><ul><li>Gasoline </li></ul></ul><ul><ul><li>Aviation gasoline </li></ul></ul><ul><ul><li>JP-4/6/8 </li></ul></ul><ul><ul><li>#2/diesel fuel </li></ul></ul><ul><ul><li>Kerosene/Jet A </li></ul></ul><ul><ul><li>Low aromatic mineral oil </li></ul></ul><ul><ul><li>Lube/hydraulic oil </li></ul></ul><ul><ul><li>Waste oil </li></ul></ul><ul><ul><li>* MADEP October 1997 </li></ul></ul><ul><ul><li>MADEP SOIL GAS SCREENING LEVELS FOR EVALUATION OF INDOOR AIR IMPACTS * </li></ul></ul><ul><ul><li>C 5 -C 8 Aliphatics (VPH) </li></ul></ul><ul><ul><li>C 9 -C 12 Aliphatics (VPH) </li></ul></ul><ul><ul><li>C 9 -C 10 Aromatics (VPH) </li></ul></ul><ul><ul><li>C 9 -C 18 Aliphatics (EPH) </li></ul></ul><ul><ul><li>Fraction > METHOD </li></ul></ul><ul><ul><li>1 GW-2 STD. </li></ul></ul><ul><ul><li>PID Soil Gas </li></ul></ul><ul><ul><li>(ppmv) </li></ul></ul><ul><ul><li>FID Soil Gas </li></ul></ul><ul><ul><li>(ppmv) </li></ul></ul><ul><ul><li>C 9 -C 18 Aliphatics (EPH) </li></ul></ul><ul><ul><li>C 9 -C 10 Aromatics (VPH) </li></ul></ul><ul><ul><li>C 9 -C 18 Aliphatics (EPH) </li></ul></ul><ul><ul><li>45 </li></ul></ul><ul><ul><li>45 </li></ul></ul><ul><ul><li>30 </li></ul></ul><ul><ul><li>30 </li></ul></ul><ul><ul><li>35 </li></ul></ul><ul><ul><li>N/A </li></ul></ul><ul><ul><li>40 </li></ul></ul><ul><ul><li>40 </li></ul></ul><ul><ul><li>N/A </li></ul></ul><ul><ul><li>N/A </li></ul></ul><ul><ul><li>40 </li></ul></ul><ul><ul><li>40 </li></ul></ul><ul><ul><li>40 </li></ul></ul><ul><ul><li>45 </li></ul></ul>
  30. 31. Background Screening <ul><ul><li>MADEP SOIL GAS SCREENING LEVELS FOR EVALUATION OF INDOOR AIR IMPACTS * </li></ul></ul><ul><ul><ul><li>VPH/EPH/ APH - measurable indoor air impacts unlikely if analyzed fractional concentrations are below MADEP values: 1,2,3 </li></ul></ul></ul><ul><ul><ul><ul><li>C 5 -C 8 Aliphatics (VPH) - 170,000 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 12 Aliphatics (VPH) - 180,000 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 10 Aromatics (VPH) - 160,000 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 18 Aliphatics (EPH) - 200,000 ug/m 3 </li></ul></ul></ul></ul><ul><ul><li>1 TO-1 (Tenax tubes); TO-2 (activated carbon); TO-14 (Summa ™ </li></ul></ul><ul><ul><li> Canisters). 2 MADEP October 1997. 3 MADEP February 2000 </li></ul></ul>
  31. 32. Background Screening <ul><li>Groundwater/surface water </li></ul><ul><ul><ul><li>VPH/EPH/ APH and target analytes - considered anthropogenic; background concentrations assumed to be zero </li></ul></ul></ul><ul><li>Indoor air </li></ul><ul><ul><ul><li>VPH/EPH/ APH – MADEP estimated generic indoor air background concentrations: 1 </li></ul></ul></ul><ul><ul><ul><ul><li>C 5 -C 8 Aliphatics (VPH) - 85 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 12 Aliphatics (VPH) - 90 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 10 Aromatics (VPH) - 80 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>C 9 -C 18 Aliphatics (EPH) - 100 ug/m 3 </li></ul></ul></ul></ul><ul><li>1 MADEP October 1997 </li></ul>
  32. 33. Background Screening <ul><li>Indoor air </li></ul><ul><ul><li>Target APH analytes 1 - MADEP indoor air background concentrations: 2,3 </li></ul></ul><ul><ul><ul><ul><li>Benzene - 21 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>1,3-butadiene – NA </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Ethylbenzene - 10 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>2-methylnaphthalene - 0 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Methyl- tert -butyl ether - NA </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Naphthalene - 5 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Toluene - 29 ug/m 3 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Xylenes - 40 ug/m 3 </li></ul></ul></ul></ul><ul><ul><li>1 MADEP February 2000. 2 MADEP October 1992 . Risk assessment Shortform. Residential exposure scenario. Policy #WSC/ORS-142-92. 2 MADEP Background Documentation for the Development of Numerical Standards. April 1994. </li></ul></ul>
  33. 35. Critical Exposure Pathways (310 CMR 40.0006 & 40.0414) <ul><li>… route(s) by which OHM(s)…are transported, or likely to be transported, to human receptors via: </li></ul><ul><ul><li>(a) vapor-phase emissions of measurable concentrations of OHMs into the living or working space of a pre-school, daycare, school or occupied residential dwelling; or </li></ul></ul><ul><ul><li>(b) ingestion, dermal absorption or inhalation …from drinking water supply wells located at and servicing a pre-school, daycare, school or occupied residential dwelling. </li></ul></ul>
  34. 36. Immediate Response Action (IRA) <ul><li>“ Shall be presumed to require the elimination and/or mitigation of Critical Exposure Pathways (CEPs)” </li></ul><ul><li>(310 CMR 40.4014(3)) </li></ul><ul><ul><li>“ may be rebutted…by a preponderance of evidence that:” </li></ul></ul><ul><ul><li>..not feasible to eliminate the CEP(s).. </li></ul></ul><ul><ul><li>..not feasible to eliminate…, …not feasible to mitigate…. </li></ul></ul><ul><ul><li>.. CEP(s) does not present an Imminent Hazard, either now or during ..Comprehensive Response Actions </li></ul></ul>
  35. 37. Substantial Release Migration <ul><li>(f) “releases to the groundwater that have resulted or are within one year likely to result in the discharge of vapors into school buildings or occupied residential dwellings.” (310 CMR 40.006 ) </li></ul><ul><li>72-hour notification requirement </li></ul><ul><li>(310 CMR 40.0313(5)) </li></ul><ul><li>IRA implemented to contain/remove OHMs </li></ul><ul><li>(310 CMR 40.0412(3)) </li></ul>
  36. 38. Risk Characterization <ul><li>… shall contain a description of the source and extent of the release of the OHMs.. (310 CMR 40.0904) </li></ul><ul><li>MADEP guidance provided in “Guidance for Disposal Site Risk Characterization – In Support of the Massachusetts Contingency Plan” (1995) and, eventually, MADEP’s “Indoor Air Sampling and Evaluation Guide” (Draft 1 February 2001) </li></ul>
  37. 39. Risk Characterization <ul><li>Non-cancer (threshold) effects: </li></ul><ul><ul><li>Compare indoor air concentrations to Allowable Threshold Concentrations (MADEP 1990, 1995) </li></ul></ul><ul><ul><li>Use an MCP Method 3 Risk Characterization and Reference Concentrations to calculate the cumulative Hazard Index (HI) (310 CMR 40.0990) . </li></ul></ul><ul><ul><li>Compare HI to applicable MCP Risk Limits. </li></ul></ul>
  38. 40. Risk Characterization <ul><li>Cancer (Non-threshold) effects: </li></ul><ul><ul><li>Use an MCP Method 3 Risk Characterization and Inhalation Unit Risk values to calculate the Excess Lifetime Cancer Risk (ELCR) (310 CMR 40.0990) . </li></ul></ul><ul><ul><li>Compare ELCR to applicable MCP Risk Limits. </li></ul></ul>
  39. 41. Risk Characterization <ul><li>Subchronic Exposures (2 weeks to 7 years) </li></ul><ul><ul><li>Time-weighted sample (2-24 hours; seasonal) </li></ul></ul><ul><ul><li>Passive sample (3-4 weeks) </li></ul></ul><ul><li>Acute Exposures ( < 24 hrs) </li></ul><ul><ul><li>1-Hour grab sample (qualitative / gross screening) </li></ul></ul><ul><ul><li>2-24 hour sample (comparison to guidelines / standards) </li></ul></ul><ul><li>Chronic Exposures ( > 7 years) </li></ul><ul><ul><li>Time-weighted sample (2-24 hours; seasonal) </li></ul></ul><ul><ul><li>Badge sample (several weeks) </li></ul></ul>
  40. 42. Risk Characterization
  41. 43. Exposure Point Concentrations (Average Daily Exposures)
  42. 44. Risk Characterization <ul><li>Imminent Hazard Evaluation </li></ul><ul><li>(310 CMR 40.0950 through 40.0955) </li></ul><ul><li>Substantial Hazard Evaluation </li></ul><ul><li>(310 CMR 40.0956) </li></ul><ul><li>Significant Risk Evaluation </li></ul><ul><li>(310 CMR 40.0990 through 40.0993) </li></ul>
  43. 45. Imminent Hazard (IH) Evaluation (310 CMR 40.0951) <ul><li>..focus of IH shall be on actual or likely exposures to human and environmental receptors under current (existing) site conditions, ..and .. an appropriate short period of time </li></ul><ul><li>… short period shall be five years (or less) </li></ul><ul><li>.. shall consider acute, subchronic and/or chronic exposures to the OHMs </li></ul>
  44. 46. Imminent Hazard (IH) Evaluation <ul><li>MCP Risk Limits: </li></ul><ul><ul><li>Hazard Index > 10 </li></ul></ul><ul><ul><li>(310 CMR 40.40.0955 (2)(c)) </li></ul></ul><ul><ul><li>Excess Lifetime Cancer Risk > 10 -5 </li></ul></ul><ul><ul><li>(310 CMR 40.40.0955 (2)(b)) </li></ul></ul><ul><li>MCP Response Action </li></ul><ul><ul><li>Immediate Response Action </li></ul></ul>
  45. 47. Substantial Hazard (SH) Evaluation (310 CMR 40.0956) <ul><li>..focus of SH shall be on possible exposures to human and environmental receptors, considering the current uses of the disposal site and surrounding environment, if applicable, any Activity and Use Limitations for the site </li></ul><ul><li>..no SH assessment required if a condition of “No </li></ul><ul><li>Significant Risk” exists for a site eligible for a Class </li></ul><ul><li>A or B Response Action Outcome </li></ul>
  46. 48. Substantial Hazard (SH) Evaluation (310 CMR 40.0956) <ul><li>..period of exposure shall be equal to or greater than time from Notification to the date that the SH is conducted, plus five years </li></ul><ul><li>..typically conducted every five years as part of the five-year review of a Class C Response Action Outcome </li></ul><ul><li>.. subchronic and/or chronic exposures to the OHMs </li></ul>
  47. 49. Substantial Hazard (SH) Evaluation (310 CMR 40.0956) <ul><li>MCP Risk Limits (310 CMR 40.40.0993(6)): </li></ul><ul><ul><li>Hazard Index > 1 </li></ul></ul><ul><ul><li>Excess Lifetime Cancer Risk > 10 -5 </li></ul></ul><ul><li>MCP Response Action </li></ul><ul><ul><li>Immediate Response Action </li></ul></ul>
  48. 50. Significant Risk Evaluation (310 CMR 40.0993) <ul><li>Focus on current and/or future exposures to OHMs considering all current and future uses of the site </li></ul><ul><li>Acute, subchronic and/or chronic exposures </li></ul><ul><li>evaluated for non-cancer and cancer endpoints </li></ul><ul><li>Conducted using MCP Method 3 Risk Characterization </li></ul><ul><li>for human health, where impact to indoor air has been </li></ul><ul><li>demonstrated (i.e., > Background) </li></ul>
  49. 51. Significant Risk Evaluation (310 CMR 40.0993) <ul><li>MCP Risk Limits (310 CMR 40.40.0993(6)): </li></ul><ul><ul><li>Hazard Index > 1 </li></ul></ul><ul><ul><li>Excess Lifetime Cancer Risk > 10 -5 </li></ul></ul><ul><li>MCP Response Action </li></ul><ul><ul><li>Risk - Implement ongoing remedial activities to </li></ul></ul><ul><ul><li>achieve Response Action Outcome </li></ul></ul><ul><ul><li>No Risk - Class A, B or C Response Outcome </li></ul></ul>
  50. 52. Summary <ul><li>Ensure existing or potential source(s) of OHMs are </li></ul><ul><li>clearly identified </li></ul><ul><li>Ensure analytical sampling is consistent with any </li></ul><ul><li>Risk Characterization to be performed </li></ul><ul><li>Establish if OHM concentrations exceed Background </li></ul><ul><li>Conduct appropriate Risk Characterization </li></ul><ul><li>Implement appropriate Response Action </li></ul>

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