Effective Communication-Vapor Intrusion Investigations Vol. V

As a continuation of our Vapor Intrusion Investigation (VII) series, we’ll take a quick look at one of the basic fundamentals for conducting a thorough VII:  effective communication with a homeowner.  Whether you’re collecting exterior soil gas samples, running 24-hour indoor air tests, or completing a building survey/questionnaire with a homeowner, if you cannot properly communicate what you’re doing and why, then you significantly decrease your odds of conducting a successful VII.  You may also never get past the front door! (As always, there is plenty of research, data, and guidance on this topic but the objective of this series is to “simplify” the discussion).  

It is vital to understand your client, who may also be the homeowner and/or occupant of where a VII may be necessary.  Put aside your budget, and that you only have 1-hour for an interview, and actually focus on your client’s concerns, fears, and questions.  Don’t just hear them, but actually listen!  Chances are, they are more confused than you realize, and to build their trust, here are some basic tips:

•  Explain the rationale for the testing…clearly, and minimize the “technical jargon.”
• Answer all questions directly…don’t deviate, or be cryptic. 
• If you don’t know the answer, tell them that, but be sure to tell them that you’ll follow-up with an answer (and make sure you follow-up right away!).
• Ask permission for everything in advance.  This includes inspecting closets, basements, cabinets, and generally anywhere where you suspect potential background contaminants may be present.  No homeowner or occupant wants a nosy stranger going through their house or personal belongings.
• Schedule everything in advance…and be prompt.
• Dress professionally…yes, this makes a difference.
• And most importantly, be polite.  (You’d be surprised how often people forget this one)

As discussed and stressed in our prior posts, this is why hiring that skilled practitioner is a good idea…as they’ll understand the value in spending the extra time communicating with the homeowner / occupant(s) / client, and building their trust.  Taking along younger staff members to observe and assist is also strongly recommended. Barring any contractual or confidentiality issues, always share your analytical results promptly. Once you have earned your client’s trust (and respect), any necessary follow-up activities, which could include mitigation, will be that much easier to discuss and potentially implement.   

We hope that you find these posts informative, and relatively useful, and your feedback is always welcome. For further information regarding the Vapor Intrusion Investigation process, please don't hesitate to contact us. tfrancis@cardinallsrp.com     

Background Contamination-Vapor Intrusion Investigations-Volume IV

As a continuation of our Vapor Intrusion Investigation (VII) series, it is vital to understand the residence / structure you are investigating prior to the collection of Indoor Air (IA) samples, and more importantly what may be stored and/or used by the occupants. For this, post we’ll take a quick look at a common household contaminant that could show up in your analysis…and leave the investigator scratching their head.  (As always, there is plenty of research, data, and guidance on this topic but the objective of this series is to simplify the discussion using typical and “hypothetical” scenarios).  

For this post, our objective is the collection of IA samples, and to identify whether a connection (or complete VI pathway) exists to the reported tetrachloroethylene (“PCE”) groundwater contamination nearby. The potential fears associated with the results of IA sampling include reduced property value and the impact on your kids’ health, so it’s understandable that some (if not most) homeowners are reluctant to follow-through, and allow such a test.  This is where experienced professionals usually excel…as they are typically able to effectively communicate and provide the sampling rationale with occupants, and conduct a thorough indoor air quality survey (or questionnaire) to identify potential background contaminants.    

Similar to prior posts, most technicians want to get in and get out, set up the required sampling canister, and not be hindered by having to complete a survey and inventory every potential indoor air contaminant. This can be time consuming, but there’s always value to being methodical.  

Start with the why: A poorly conducted indoor air survey will inhibit an investigator’s ability to assess whether sample results are “representative” of actual vapor intrusion conditions, or merely the result of background compounds or contaminants. As we’ve stressed in prior posts, this is why hiring that skilled practitioner is a good idea…as they’ll understand the value in spending the extra time completing a survey and product inventory, and also communicating with the occupant(s).    

Correlation of Results: Upon completion of a “properly” conducted IA sampling event, which included the collection of an ambient (outside) air sample, basement, first floor and second floor sample, numerous compounds were detected in the (EPA Method) TO-15 analyses including PCE.  PCE is the primary contaminant of concern in this scenario and was identified above action levels in a nearby groundwater monitoring well, and from a subsurface soil-gas sample collected in the basement.  With this information, it’s then up to the investigator to evaluate if the VII pathway is “complete.”  A quick look at the PCE data revealed the following:

• MW-1 (groundwater): 75(ug/L)
• Sub-Slab Soil Gas: 620 (ug/m3)
• Basement-Indoor Air: 0.6 (ug/m3)
• First Floor-Indoor Air: 10.2 (ug/m3)
• Second Floor-Indoor Air: 7.6 (ug/m3)
• Ambient (outside) Air: Not Detected.

The groundwater and sub-slab soil gas results displayed fairly high levels of PCE (which are likely above state action levels), but the indoor air results tell a different story. The expected highest concentrations of PCE would have been in the basement, not the first or second floors.  The first floor result is also potentially above an indoor air screening level.  At this point the experienced investigator would have to refer back to the completed building survey and product inventory to determine what potential background sources were present, and if the occupants followed the instructions that were provided (e.g. use of fireplaces, air fresheners, cleaning products, etc.).  IF the survey and inventory was completed properly, and IF the occupants were forthright, the answers will come quickly and potential follow-up activities and decisions (including any regulatory reporting) could be completed without delay.

For this scenario, no recent dry cleaned clothes were brought to the residence, no individuals worked at facilities where PCE may be used (and inadvertently brought home), and no interior cleaning products were used. However, the occupants indicated that they didn’t use air fresheners; but they frequently used various types of scented candles on both floors AND mistakenly used a scented candle on the first floor at the time of the sampling event.  Unbeknownst to some, scented candles may contain several organic compounds including (but not limited to) PCE, Formaldehyde, Acetaldehyde, Naphthalene, and Polycyclic Aromatic Hydrocarbons (PAHs).  Based on this information, and also due to elevated levels of Formaldehyde in the IA analyses, the logical conclusion in this scenario was to attribute the indoor PCE concentrations to the background contaminant, and not the nearby groundwater contamination.  More importantly, the Vapor Intrusion pathway was deemed incomplete, and mitigation was not unwarranted (using the state’s regulations and guidelines). 

Although mitigation is not warranted, staying abreast of remedial activities in the neighborhood, and the actions of responsible parties, would be advisable based on the contaminant concentrations in the groundwater and the sub-slab soil gas.  Re-testing may also be recommended if any changes occur in the residence that could complete the VI pathway (e.g. installation of a sump pit, french drain, etc.).  Additionally (and unofficially), providing some literature to the occupants on the long-term use of candles (and other indoor air contaminants including mothballs, nail polish, etc.) may also be a nice gesture!

In future posts for this VII series, we’ll take a look at some mitigation options, and elaborate on “effective communication techniques” with homeowners.  Stay tuned.  

We hope that you find these posts informative, and relatively useful, and your feedback is always welcome. For further information regarding the Vapor Intrusion Investigation process, please don't hesitate to contact us. tfrancis@cardinallsrp.com     

How Much and How Long Will It Take? Vapor Intrusion Investigations-Volume II

As a follow-up to our first Vapor Intrusion Investigation (VII) post, let’s take a quick look at the collection of Indoor Air (IA) samples.  As discussed previously, there is plenty of research, data, and guidance on this topic but let’s simplify it. For this post, lets’ assume that Sub-Slab Soil Gas samples were already collected, and the laboratory has provided data.  This is why hiring that skilled practitioner was a good idea…as they’ll know if the data obtained is representative, if it’s garbage, and how to effectively interpret what the results “mean.”  *Demonstrating if there is a connection to that gas station next door is like connecting the dots, but hopefully the environmental professional you hire understands that that connector line may be crooked, diagonal, blocked, under water, in fractured bedrock…you get the picture (and maybe not as simple as you’d like).   

For example:  The station next door leaked gasoline into the groundwater, so the primary compounds to be on the lookout for would include Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX).  There are some others that would likely turn up, but let’s focus on the primary players.  To “connect the dots” or to evaluate the “pathway,” look to see if your Sub-Slab Soil Gas samples have detections of those BTEX compounds.  If they do, and the results are above a regulatory screening level, you potentially need to go to the next step and collect Indoor Air samples.   Your client won’t be thrilled, but let’s answer their question…“How much will it cost and how much longer will it take?”  

Start with the why: Compounds were detected in Sub-Slab Soil Gas samples and the collection of Indoor air samples are necessary to assess if the vapor intrusion pathway is complete or incomplete. In laypersons speak: Gasoline vapors were identified below that basement slab, and you need to make sure they’re not getting into the house.

How much and how long will it take? Every Site is different, so let’s keep it simple again and assume that the Site in question contains a small house, is located next to that gasoline station (with leaking USTs), and you’ve already obtained the appropriate access from the property owner (and notified the regulatory agencies-if applicable).  A typical approach is outlined as follows:  

1. Review all available Sub-Slab Soil Gas data, and compare it to the product inventory collected during the initial walk-though (hopefully the investigator didn’t cut that initial corner). If those samples were collected properly, you probably shouldn’t see 1, 4 Dichlorobenzene (typically found in mothballs) in your results.  If you see large detections of typical “Common Household” contaminants in your results, there was probably some leakage in the Sub-Slab Soil Gas sampling train (e.g. loose fittings, improper seal around sampling point, etc.). At that point, the investigator should decide if re-sampling is necessary.  Don’t go to the next step (and collect Indoor Air samples) and don’t waste your clients’ time and money, if you can’t justify that your data is representative.    
2. Assuming that all prior data is “useable,” Indoor Air sampling points should be identified.  The number and locations should be based on professional judgment and in accordance with accepted guidance documents.  Assume one (1) sample is needed from the basement, and one (1) from the first floor.  Tip: Try to place the sample canisters in areas where they won’t be disturbed or knocked over. 
3. Identify Ambient Air Sampling points.  (This is a control sample to see if outside or ambient conditions are contributing to the quality of the indoor conditions.). Assume one (1) sample is needed and make sure you check the weather forecast.
4. Set-up and collect Indoor/Ambient Air samples (EPA Method TO-15).  In most states, this generally takes about 24-hours for each, using certified-clean, 6-liter Summa Canisters.   Collect / record the appropriate data (start and stop times, vacuum pressure, weather conditions, etc.) and submit to a certified Laboratory.  Tip: Be extremely thorough and methodical; pre-arrange sample pick-up times with your client / homeowner in advance as you’ll need to return to the property the next day; don’t overtighten the Summa Canister regulators…that would be bad.
5. Assuming that standard analytical turnaround times are used, the data should be received in about two (2) weeks, at which time the investigator can review and compare the data to the appropriate screening levels.

So, after considering all of the above, the process identified above will typically take about three (3) to four (4) weeks and cost between $3,000 and $4,000.  Additional costs should be considered if an Immediate Environmental Concern (IEC) is identified.  In the next post for this VII series, we’ll dissect the data review component, as future mitigation (if necessary) will rely on it. Stay tuned.  

For further information regarding the Vapor Intrusion Investigation process, please don't hesitate to contact us. tfrancis@cardinallsrp.com

How Much and How Long Will It Take? Vapor Intrusion Investigations- Volume I

To continue with the previous “How Much and How Long Will It Take?” posts, we’ll take a quick look at conducting Vapor intrusion Investigations (VII), and specifically two (2) initial phases of a VII (Building Survey and Sub-Slab Soil Gas Sampling).  There is plenty of research, data, and guidance on this topic but let’s simplify it.  Generally, a VII is conducted after some preliminary work (Phase I or II ESA, Preliminary Assessment, Groundwater Sampling, etc.) has already been completed at a specific site (or adjacent site), and the investigator “suspects” that harmful vapors emanating from the subsurface soil or groundwater are entering the indoor air of a structure.  Skilled practitioners, using a multiple lines of evidence approach, know how to gather the data needed to “properly” assess whether a true issue is present (and if mitigation is needed).  So...why conduct a VII and "How much will it cost and how long will it take?" 

Start with the why: the purpose of a VII is to evaluate whether volatile chemicals are entering indoor air (or have the potential to enter indoor air). In laypersons speak: Is the air you breathe safe? This is what a properly conducted VII should hopefully answer.

How much and how long will it take? Every Site is different, so let’s keep it simple again and assume that the site in question contains a structure that is less than 1,500 square feet, is located next to a gasoline station (with leaking USTs), and you’ve already obtained the appropriate access from the property owner (and notified the regulatory agencies-if applicable).  Note: If you’re the homeowner, and an environmental professional tells you $500 and it will take 1-week to complete, seriously consider showing them the door within 15 minutes.  Conversely, if you’re told that it’ll take 3-months and the costs will exceed $20k, tell them you never liked Cadillacs.  Everything takes time and comes at a cost, but keep it simple, work methodically, and commit to the process.  A typical approach is outlined as follows:

 1.     Review all available site data, complete a building survey and evaluate what (background) indoor contaminants may be present. Complete a product inventory (e.g. mothballs, ASTs, cleaning products, candles, etc.).  Talk with the homeowner. Look at preferential pathways. Look at building structure, type and age.  Slab-on-grade? Basement?  Before any samples are even collected, this is the starting point and it needs to be done thoroughly.   Don’t skimp here.  It’ll cost you later if you do.

2.     Identify Sub-Slab Soil Gas Sampling points.  The number and locations should be based on professional judgment and in accordance with accepted guidance documents.  Assume a minimum of two (2) are needed.

3.     Install “temporary” soil gas probes below the slab, conduct appropriate leak testing (e.g. Helium tracer, etc.), and purge the lines.  Spend the extra time ensuring a tight seal, and that tracer tests are accurate. It pays off later.

4.     Collect sub-slab soil gas samples.  In New Jersey, this generally takes about 5-minutes per location using certified-clean, 1-liter Summa Canisters.   Collect / record the appropriate data (start and stop times, vacuum pressure, etc.) and submit to a certified Laboratory for (EPA Method TO-15) analysis.  

5.     Assuming that standard analytical turnaround times are used, the data should be received in about two (2) weeks, at which time the investigator can review and compare the data to the appropriate screening levels, and (hopefully) determine if the VI pathway is complete or incomplete with a high degree of confidence.

So, after considering all of the above, a properly conduced VII of this nature will typically take about four (4) weeks, and cost between $3,500 and $5,000.  Additional costs should be considered if indoor air and ambient air samples are collected concurrently with sub-slab soil gas samples.  In the next post for this VII series, we’ll take a deeper look at the process, the collection of indoor air samples…and how a background contaminant source can throw a pretty good curveball.  Stay tuned.

For further information regarding the Vapor Intrusion Investigation process, please don't hesitate to contact us. tfrancis@cardinallsrp.com