21007_Hoke Street_VIR_20180626

Aptus Management, PLLC
Environmental Management Solutions
Aptus Management, PLLC 109 Amber Court Carrboro, NC 27510
June 26, 2018
Sarah Hardison Young VIA EMAIL: [e-mail] Brownfields Project Manager
NC DEQ Division of Waste Management 217 W Jones St. Raleigh, NC 27603-6100
SUBJECT: VAPOR INTRUSION INDOOR AIR TESTING REPORT
PASSAGE HOME SITE – RALEIGH, NORTH CAROLINA BROWNFIELDS PROJECT NUMBER: 21007-17-092
Dear Ms. Young:
We are pleased to provide this indoor air (VI) testing report for Passage Home’s property located at 500 Hoke Street in Raleigh. The work was performed in accordance with the revised work plan you approved on April 30, 2018.
A site location map is provided in Drawing 1. A site map is also provided in Drawing 2 for
the Passage Home site, which includes three parcels: 500 Hoke Street (with the existing building that was tested), 506 Hoke Street, and 1412 Garner Road.
SAMPLING OBJECTIVE
Sub-slab soil gas sampling of the existing building was performed during October 2017. Four locations were tested at the building quadrants (see Drawing 3), which found minimal detections of volatile organic compounds (VOCs) except for one analyte, tetrachloroethylene (PCE). At the southwest building quadrant sample location (SS-3),
PCE was detected at a concentration greater than the residential soil gas screening level
(SGSL). At 590 ug/m3, the PCE level at this location beneath the slab was approximately twice the SGSL of 280 ug/m3.
While PCE was above the screening level, risk assessment performed using the October
2017 NCDEQ’s Risk Calculator, however, showed that the cumulative risk from vapor
intrusion was acceptable, with a cumulative carcinogenic risk of 4.7E-6 and a cumulative hazard index of 0.6 for residential receptors.
On May 7, 2018, Aptus conducted indoor air sampling to evaluate whether PCE levels
inside the building are within acceptable guideline levels and protective of future site
occupants. The NCBP-approved list of site-specific analytes for this round of testing is shown below:
Vapor Intrusion Indoor Air Testing Report June 26, 2018 Passage Home Site - Raleigh, North Carolina
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Site-Specific Laboratory Analytes
Acetone 2-Butanone (MEK)Carbon TetrachlorideChloroformCyclohexanecis-1,2-dichloroethene
trans-1,2-dichloroethene Ethyl Acetate Ethylbenzene Heptane Hexane 2-Hexanone (MBK)
Isopropanol Naphthalene Propene Tetrachloroethylene Tetrahydrofuran Toluene
1,1,1-Trichloroethane Trichloroethylene (TCE) 1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene Vinyl Chloride Xylenes
INDOOR AIR SAMPLING
To evaluate worst-case indoor air conditions, the sampling was performed with no ventilation while the building was closed over a 24-hour period. Aptus collected samples at five locations inside the building, including a duplicate. One concurrent outdoor ambient air sample was also collected upwind (to the south) of the building for background
comparison purposes. Drawing 3 shows the locations of the previous sub-slab sampling along with the current floor plan. Drawing 4 denotes the indoor air sampling locations detailed in this report, along with the architect’s proposed interior building layout.
The work was conducted in accordance with current Brownfield’s Program VI screening
levels and guidance1. Additionally, per NCBP comments, since the prior October sampling was conducted during warm weather conditions (ambient temperature 71.5 °F), this round of indoor air sampling was conducted under similar conditions (i.e., when average temperatures remain above 60 °F) so concurrent soil gas sampling would not be required.
Being primarily a warehouse, the interior of the building (Drawing 3) is quite open with few ceiling areas2 and minimal wall partitions throughout. Locations with interior doors (storage rooms, bathrooms, closets) were kept open during the testing so that the indoor air throughout the entire building could be characterized.
The testing lab was contacted prior to sampling to ensure that the reporting limits would be below residential Vapor Intrusion Screening Levels (Feb. 2018 version). Per EPA method TO-15, the analysis includes a lab control sample and a lab blank sample for QA/QC purposes.
An Indoor Air Building Survey and Sampling Form is attached (Appendix A), which summarizes building characteristics and potential outdoor/indoor contaminant sources. Photos showing the rooms and sampling arrays are provided via a link due to the file size of the photos (https://photos.app.goo.gl/r8XRqFCUZnRjD98h9) – see also Appendix B.
1 “Vapor Intrusion Guidance”, NCDENR, Division of Waste Management, Brownfields Program, March 2018, Version 2. 2 The north portion of the building has “false” or “dropped” ceilings, which are open to and accessible from the southern warehouse areas.
Vapor Intrusion Indoor Air Testing Report June 26, 2018 Passage Home Site - Raleigh, North Carolina
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Sample Collection
•Aptus collected indoor air samples from five (5) locations across the buildingfootprint, per Drawing 4. The sample locations were identified as A- 1 through A-5.
A duplicate sample was collected using an inline tee at location A-1.
•An outdoor ambient air sample (A-6) was obtained simultaneously with the indoorsamples for background comparison.
•The samples were collected using 6-L Summa canisters equipped with 24-hourflow regulators at each location. The canisters were placed such that the inlet portswere within breathing zone height (e.g., approximately five feet).
•The canisters were shipped from the lab with initial vacuum readings of – 30 inches
of mercury (“Hg). At the start of sampling, the canister vacuums ranged from -28” to-29” Hg. After 24 hours had elapsed, the vacuums of each canister ranged from -6”to -10” Hg (see the lab analysis request/chain of custody form). Thus, the initialvacuums were within 10% of the shipped values and final vacuums maintainedgreater than -5” Hg at the end of the 24-hour sampling event, as required by the
work plan.
•Laboratory analysis request forms were prepared, and the samples were shippedunder proper chain of custody for laboratory analysis of the NCBP-approved list
of site-specific analytes using EPA Compendium Method TO-15 “Determination
of Volatile Organic Compounds (VOCs) in Air Collected in Specially-PreparedCanisters and Analyzed by Gas Chromatography/Mass Spectrometry (GC/MS)”.
Laboratory Results
The findings are summarized in Table 1. The summa canister and corresponding flow controller information are denoted on the chain of custody/lab request form, as well as the initial and final canister pressures during testing.
INDOOR AIR SAMPLING RESULTS
The results of the EPA Method TO-15 laboratory analyses were compared to the NCDEQ’s February 2018 list of Residential Vapor Intrusion Indoor Air Screening Levels (IASLs). PCE was not detected indoors except for an estimated (J-value) concentration
below the reporting limit (RL) of 0.13 ug/m3 in Sample A-1. The duplicate sample at this
location, and the remaining locations, were non-detect for PCE.
Carbon tetrachloride and chloroform were detected uniformly at or near the IASL “A” category for these analytes inside the building. However, the same concentration levels
were found in the ambient air/background sample. Thus, these analytes do not appear to
be due to vapor intrusion or indoor air sources. Moreover, these concentrations were well below the acceptable IASL “B” and “C” categories (i.e., 10% and lower).
Naphthalene was detected indoors above its IASL. Each of the sample locations were
found to be above the most stringent IASL category “A” level of 0.083 ug/m3; however, at
the category “B” and “C” levels, only one location (A-2, in the northwest quadrant) was above the screening level.
Vapor Intrusion Indoor Air Testing Report June 26, 2018 Passage Home Site - Raleigh, North Carolina
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The remainder of site-specific analytes were found to be non-detect, or at 10% and lower of the most respective screening levels.
CONCLUSIONS AND RECOMMENDATIONS
The main concern was the possibility of PCE in the building indoor air above screening levels because it was found in the sub-slab soil gas at an elevated concentration. PCE is also present in groundwater at the site attributable to the historical PCE release at the nearby Ashland Chemical site.
PCE was not detected in 4 of the 5 indoor samples and only detected at an estimated value of 0.13 ug/m3 (A-1) in the remaining location. The concentration in A-1 corresponds to only 1.6% of the stringent IASL “A” level. Based on this, there is no unacceptable risk of vapor intrusion due to PCE.
Naphthalene was measured in all the indoor air samples about its IASL. Its presence was uniform in 4 of the 5 samples and more elevated at location A-2 in the northwest building quadrant.
Naphthalene is a common material found in fossil fuels, asphalt, mothballs, tobacco
smoke, and a wide variety of industrial and consumer products. The presence of naphthalene in the building’s indoor air is not believed to be associated with a subsurface release given it was not measured at appreciable sub-slab levels – it was detected in only one sub-slab sampling location (SS-4) at less than 18% of the SGSL. Instead, based on the weight of evidence, the most plausible explanation for the naphthalene is one or more
background sources that could include fuel in pressure washers or motor pump oil containers stored indoors, roofing flashing cement and asphaltic materials (there were recent roof repairs) or other building materials (see inventory notes in Appendix A).
Based on this assessment and the earlier sub-slab soil gas testing we completed, we do
not believe there is an unacceptable risk due to vapor intrusion. Further, given the lack of PCE in the indoor air, the slab attenuation appears to be very good at mitigating the potential vapor intrusion pathway.
Our recommendation is that no further assessment of VI risk is required and no mitigation
for VI risk is needed associated with the repurposing of the on-site building.
Vapor Intrusion Indoor Air Testing Report June 26, 2018 Passage Home Site - Raleigh, North Carolina
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If you have questions, please feel free to contact us at [phone].
Sincerely, APTUS MANAGEMENT, PLLC
John Gallagher, PE Robert D. Hill, PE Engineer of Record Principal Consulting Engineer
Attachments
cc: S. Vebber – Passage Home R. Hill – RDHEC

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DRAWINGS
SITE PARCEL /PROPERTY BOUNDARYADJACENT PARCEL /PROPERTY BOUNDARIESLEGENDFORMERASHLANDCHEMICALFACILITYAUTO REPAIRSERVICEFACILITY500 HOKE STREETSITE - EXISTING BUILDING506 HOKE STREET1412 GARNER ROAD
SS-1SUB-SLAB SOIL GASSAMPLE LOCATIONLEGENDSS-3SS-1SS-2SS-4
INDOOR / OUTDOOR AIRSAMPLE LOCATIONLEGEND

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TABLES
TABLE 1 - VAPOR INTRUSION INDOOR AIR SAMPLING RESULTS
MAY 7 - 8, 2018
PASSAGE HOME SITE - 500 HOKE ST., RALEIGH, NC
Residential
Indoor Air (A),
ug/m3
Residential
Indoor Air (B),
ug/m3
Residential
Indoor Air (C),
ug/m3
A-1 A-1 (DUP)A-2 A-3 A-4 A-5 A-6 (Ambient)
Acetone 6500 6500 6500 15 15 38 12 12 11 11
2-Butanone (MEK)1000 1000 1000 2.7 J 1.3 J 2.3 J 1.7 J 1.7 J 1.3 J 1.4 J
Carbon Tetrachloride 0.47 4.7 21 0.38 0.47 0.45 0.45 0.47 0.48 0.47
Chloroform 0.12 1.2 12 0.11 J 0.10 J 0.11 J ND (0.073)0.11 J 0.12 J 0.11 J
Cyclohexane 1300 1300 1300 ND (0.086)ND (0.086)ND (0.098)ND (0.098)ND (0.098)ND (0.098)ND (0.098)
cis-1,2-Dichloroethylene ~~~ND (0.057)ND (0.057)ND (0.065)ND (0.065)ND (0.065)ND (0.065)ND (0.065)
trans-1,2-Dichloroethylene ~~~ND (0.055)ND (0.055)ND (0.063)ND (0.063)ND (0.063)ND (0.063)ND (0.063)
Ethyl Acetate 15 15 15 0.22 0.41 2.5 0.37 0.31 0.48 ND (0.11)
Ethylbenzene 1.1 11 110 0.39 0.39 0.44 0.32 0.28 0.27 0.11 J
Heptane 83 83 83 0.41 0.37 1.6 0.3 0.28 0.26 0.14 J
Hexane 150 150 150 0.35 J 0.39 J 1.1 J 0.33 J 0.36 J 0.32 J 0.33 J
2-Hexanone (MBK)6.3 6.3 6.3 0.65 ND (0.085)ND (0.097)ND (0.097)ND (0.097)ND (0.097)ND (0.097)
Isopropanol ~~~1.4 J 3.7 2.5 J 1.3 J 1.1 J 1.1 J 0.72 J
Naphthalene 0.083 0.63 0.63 0.21 0.19 2.4 0.19 J 0.20 J 0.18 J ND (0.16)
Propene 630 630 630 0.79 J ND (0.060)ND (0.068)ND (0.068)ND (0.068)ND (0.068)ND (0.068)
Tetrachloroethylene 8.3 8.3 8.3 0.13 J ND (0.13)ND (0.15)ND (0.15)ND (0.15)ND (0.15)ND (0.15)
Tetrahydrofuran 420 420 420 ND (0.064)ND (0.064)ND (0.073)ND (0.073)ND (0.073)ND (0.073)ND (0.073)
Toluene 1000 1000 1000 1.8 1.7 7.1 1.6 1.3 1.3 0.71
1,1,1-Trichloroethane 1000 1000 1000 ND (0.072)ND (0.072)ND (0.082)ND (0.082)ND (0.082)ND (0.082)ND (0.082)
Trichloroethylene 0.42 0.42 0.42 ND (0.076)ND (0.076)ND (0.087)ND (0.087)ND (0.087)ND (0.087)ND (0.087)
1,2,4-Trimethylbenzene 13 13 13 0.52 0.48 0.63 0.4 0.42 0.37 ND (0.13)
1,3,5-Trimethylbenzene 13 13 13 0.16 J 0.16 J ND (0.12)0.13 J 0.13 J ND (0.12)ND (0.12)
Vinyl Chloride 0.17 1.7 17 ND (0.057)ND (0.057)ND (0.064)ND (0.064)ND (0.064)ND (0.064)ND (0.064)
Xylene, m&p 21 21 21 1.4 1.3 1.5 1.1 0.97 0.93 0.33 J
Xylene, o-21 21 21 0.55 0.53 0.6 0.43 0.42 0.39 0.14 J
NOTES:
1. ND = Not detected above the lab reporting limits shown in parenthesis.
2. NT = Not tested.
3. ~ = No IHSB Residential or Non-Residential screening limits limits.
4. Values in italics exceed the IHSB Residential Indoor Air Screening Limits (Feb 2018).
5. Bold values exceed the IHSB Non-Residential Indoor Air Screening Limits (Feb 2018).
Parameter
SAMPLING LOCATION

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APPENDICES

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APPENDIX A
INDOOR AIR BUILDING SURVEY AND SAMPLING FORM
INDOOR AIR BUILDING SURVEY
and SAMPLING FORM

Site Name: ____________________________________ ID#: ______________________

Preparer’s name: ________________________________ Date: __________________________

Preparer’s affiliation: ____________________________ Phone #: _______________________

Part I - Occupants

Building Address: ____________________________________________________________________

Property Contact: _______________________________ Owner / Renter / other: ______________

Contact’s Phone: home ( )__________ work ( )______________ cell ( )____________

# of Building occupants: Children under age 13 _____ Children age 13-18 ______ Adults _____

Part II – Building Characteristics

Building type: residential / multi-family residential / office / strip mall / commercial / industrial

Describe building: ________________________________________ Year constructed: _________

Sensitive population: day care / nursing home / hospital / school / other (specify): _______________

Number of floors below grade: ______ (full basement / crawl space / slab on grade)

Number of floors at or above grade: ______

Depth of basement below grade surface: ______ ft. Basement size: _______ ft2

Basement floor construction: concrete / dirt / floating / stone / other (specify): ________________

Foundation walls: poured concrete / cinder blocks / stone / other (specify) ________________

Basement sump present? Yes / No Sump pump? Yes / No Water in sump? Yes / No

Type of heating system (circle all that apply):
hot air circulation hot air radiation wood steam radiation
heat pump hot water radiation kerosene heater electric baseboard
other (specify): ________________________

Type of ventilation system (circle all that apply):
central air conditioning mechanical fans bathroom ventilation fans
individual air conditioning units kitchen range hood fan outside air intake
other (specify): _________________

Type of fuel utilized (circle all that apply):
Natural gas / electric / fuel oil / wood / coal / solar / kerosene

Are the basement walls or floor sealed with waterproof paint or epoxy coatings? Yes / No

Is there a whole house fan? Yes / No

Septic system? Yes / Yes (but not used) / No

Irrigation/private well? Yes / Yes (but not used) / No

Type of ground cover outside of building: grass / concrete / asphalt / other (specify) _____________

Existing subsurface depressurization (radon) system in place? Yes / No active / passive

Sub-slab vapor/moisture barrier in place? Yes / No
Type of barrier: ____________________________

Part III - Outside Contaminant Sources

Other stationary sources nearby (gas stations, emission stacks, etc.): _____________________________

Heavy vehicular traffic nearby (or other mobile sources): ______________________________________

Part IV – Indoor Contaminant Sources

Identify all potential indoor sources found in the building (including attached garages) and crawlspace (if
present), the location of the source (floor and room), and whether the item was removed from the building
48 hours prior to indoor air sampling event. Any ventilation implemented after removal of the items
should be completed at least 24 hours prior to the commencement of the indoor air sampling event.

Potential Sources Location(s) Removed
(Yes / No / NA)
Gasoline storage cans
Gas-powered equipment
Kerosene storage cans
Paints / thinners / strippers
Cleaning solvents
Oven cleaners
Carpet / upholstery cleaners
Other house cleaning products
Moth balls
Polishes / waxes
Insecticides
Furniture / floor polish
Nail polish / polish remover
Hairspray
Cologne / perfume
Air fresheners
Fuel tank (inside building) NA
Wood stove or fireplace NA
New furniture / upholstery
New carpeting / flooring NA
Hobbies - glues, paints, etc.

Part V – Miscellaneous Items

Do any occupants of the building smoke? Yes / No How often? ______________

Last time someone smoked in the building? ____________ hours / days ago

Does the building have an attached garage directly connected to living space? Yes / No

If so, is a car usually parked in the garage? Yes / No

Are gas-powered equipment or cans of gasoline/fuels stored in the garage? Yes / No

Do the occupants of the building have their clothes dry cleaned? Yes / No

If yes, how often? weekly / monthly / 3-4 times a year

Do any of the occupants use solvents in work? Yes / No

If yes, what types of solvents are used? _______________________________________

If yes, are their clothes washed at work? Yes / No

Have any pesticides/herbicides been applied around the building or in the yard? Yes / No

If so, when and which chemicals? _________________________________________________

Has there ever been a fire in the building? Yes / No If yes, when? _____________

Has painting or staining been done in the building in the last 6 months? Yes / No

If yes, when __________________ and where? ____________________________

Part VI – Sampling Information

Sample Technician: ____________________________ Phone number: ( ) _______ - __________

Sample Source: Indoor Air / Crawlspace Air / Sub-Slab / Near Slab Soil Gas / Exterior Soil Gas

Sampler Type: Tedlar bag / Sorbent / Stainless Steel Canister / Other (specify): _________________

Analytical Method: TO-15 / TO-17 / other: _________ Cert. Laboratory: _________________

Sample locations (floor, room):

Field ID # _____ - ________________________ Field ID # _____ - __________________________

Field ID # _____ - ________________________ Field ID # _____ - __________________________

Were “Instructions for Occupants” followed? Yes / No

If not, describe modifications: __________________________________________________________

Provide Drawing of Sample Location(s) in Building

Part VII - Meteorological Conditions

Was there significant precipitation within 12 hours prior to (or during) the sampling event? Yes / No

Describe the general weather conditions: ___________________________________________________

_____________________________________________________________________________________

Part VIII – General Observations

Provide any information that may be pertinent to the sampling event and may assist in the data
interpretation process (e.g., observed that drycleaner operated with door or windows propped open for
ventilation).

(Adapted from the NJDEP Vapor Intrusion Guidance, October 2005)

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APPENDIX B PHOTOGRAPHS

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Please enter the following link in your Internet
browser to view project photographs and captions

https://photos.app.goo.gl/r8XRqFCUZnRjD98h9

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APPENDIX C LABORATORY REPORT AND CHAIN OF CUSTODY FORMS
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