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March 2019 Newsletter

 

In This Issue

The LSPA would appreciate your feedback on the articles included in the March 2019 newsletter. Please send your comments and questions to [email protected].

President's Message, "Season of Change and Seasonal Change"

 

As I write this, my countdown app says there are 6 days and 17 hours to the first day of spring. While not a particularly harsh winter as records go, every person I speak to is ready for spring, ready for the changes it will bring, ready for winter to be over. For our LSPA community, perhaps the biggest change on the horizon is the upcoming release of the MCP amendments. I can’t predict the actual release date of the regulatory revisions, but it is worth noting that there is plenty of buzz about them. The upcoming regulation changes will be the topic of the LSPA’s March 19 membership meeting, and those changes were featured prominently in the most recent Waste Site Cleanup Advisory Committee meeting held on February 28.

The LSPA Regulations Committee is poised to dive into the public comment version of the 2019 MCP as soon as it is released, and they will be reaching out to all of you for your review comments and suggestions. We understand there are 97 notes to reviewers and plenty of redlined changes in the upcoming draft, so there’s lots to do to effect change within a relatively short public comment period. Ably co-chaired by LSPs Joe Roman (GEI Consultants) and Dan LaFrance (Fuss & O’Neill), the Regulations Committee has provided a preview of what this season of regulatory change will bring in the form of a video recap of the recent Advisory Committee meeting. Watch Joe Roman’s short video summary here - it’s an LSPA version of a hint of spring, so to speak. You can also watch the Advisory Committee meeting presentation on MCP amendments online here.

The “new” MCP will usher in a host of changes, including such things as changes to AEPMMs (our February 2019 member meeting topic), clarifications on tier classification extensions and the application of remedial additives, and reportedly even proposed Reportable Concentrations and Method 1 Standards for PFAS. Included among all these changes will be proactive incorporation of climate change and resiliency into the MCP process. Seasonal change considerations will be part of Response Action Performance Standards going forward, and LSPs will need to become familiar with Massachusetts EOEEA’s Climate Action policies and guidelines and how local communities are embracing them. We are working to help in this regard. The LSPA is collaborating with our very own Past President Dot McGlincy, LSP, and now Executive Director of the Massachusetts Association of Conservation Commissions, to develop and present an upcoming workshop for MACC and LSPA members on the topic.

Yes, a season of change and seasonal change are both upon us. As always, I encourage you to stay engaged with your LSPA community as we explore these changes. Six days, 15 hours and 59 minutes until it is officially spring. Bring it on! We are ready!

  

Marilyn M. Wade, P.E., LSP, President

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Blog Highlights

 

In addition to the article posted below from February 2019, the LSPA Blog, called LSPA News & Announcements on the homepage of our website, has useful information on the Newly Released EPA PFAS Action Plan, the Vacant Environmental Seat on the LSP Board, and information about upcoming events. Click here for past blog posts and visit the LSPA website regularly for new postings.

LSPA Comments on PFAS Petition to MassDEP
The LSPA submitted this response to MassDEP's invitation to offer written feedback on the "PFAS Petition" by the Conservation Law Foundation and Toxics Action Center. Read the letter here. 

MassDEP Response to CLF and Toxics Action PFAS Petition
In a January 28, 2019 email, Douglas E. Fine., Assistant Commissioner, Bureau of Water Resources, MassDEP wrote:

As you know, MassDEP received a “Petition for Rulemaking to Establish a Treatment Technique Drinking Water Standard for Per- and Polyfluoroalkyl Substances” on October 25, 2018 from the Conservation Law Foundation and Toxics Action Center.  In accordance with regulatory requirements under 310 CMR 2.03 and 2.04, MassDEP held a public meeting on January 16, 2019 to consider the petition and to take comments on the petition. This opportunity allowed for representatives of the Conservation Law Foundation and the Toxics Action Center to present their views on the petition to 71 participants attending the meeting in person, and more than 80 watching via on-line stream.  The public meeting also allowed for 21 stakeholders to formally offer their views. In addition, MassDEP received written comments from 45 different individuals and organizations. MassDEP greatly appreciates attention to this important matter from the petitioners, and the agency is very appreciative of the participation of all stakeholders through their written and oral comments, and attendance and viewing of the public meeting.

MassDEP has responded to the petition on January 28, 2019.  You can find MassDEP’s response at the following link: https://www.mass.gov/lists/pfas-information-a-petition-for-rulemaking-to-establish-a-treatment-technique-drinking-water#massdep-action-on-petition-to-establish-a-treatment-technique-drinking-water-standard-

MassDEP sees continued engagement with the petitioners and other stakeholders as essential during consideration of these processes and other agency actions. Thank you for your continued interest and work on efforts to address public health concerns regarding PFAS in drinking water.

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Practice Tips and Key Takeaways from MassDEP Audit and Enforcement Team Meeting with LSPA's Loss Prevention Committee

 

For two hours on October 4, 2018, representatives of the LSPA’s Loss Prevention Committee (LPC) met with MassDEP’s Audit Section Chiefs and other MassDEP staff to share observations from the LSPA’s FY 17 NOAF reviews and to solicit MassDEP input on other LSPA issues of interest.  This is an annual meeting that is always very productive.  MassDEP participants were:

  • Lisa Alexander, BWSC Audits & Enforcement Coordinator
  • Debbie Marshall-Hewlitt, SERO Audit Section Chief
  • Rebecca Woolley, CERO Audit Section Chief
  • Dave LaPusata, NERO Audit Section Chief
  • John Ziegler, WERO Audit Section Chief
  • Jenny Wharff, MassDEP Boston
  • Brian Roden, MassDEP Boston

Attending from the LSPA were Crista Trapp, Risk Assessor, LPC Chair; Jim Zigmont, LSP, LPC Past Chair; Jeanine Grachuk, environmental attorney, LSPA Board; and Wendy Rundle, LSPA Executive Director.

Provided below are our summary notes along with practice tips and key takeaways from the meeting.  

Overview and Observations from LPC’s FY 17 NOAF Reviews

  • Categories and numbers of FY 17 NOAFs that were reviewed by LPC members: LNAPL (8), Nature and Extent (6), Historic Fill (1), NONs to LSPs (1), PIP Sites (1), Downgradient Property Status (9), Risk Characterization (16), Temporary Solutions (29), AULs (142), Soil Management (1), Vapor Intrusion (42), MNA (4), and ROS (19).
  • LSPA observed trends:  Number of NOAFs is declining.  Total number of NOAFs in FY 16 was 550, FY 17 was 450, FY 18 was 386.  MassDEP’s explanations included:
    • Auditing of sites has slowed down, especially in NERO, where audit staff have been focused on closed TCE sites.
    • Some regions are really focusing on the “front end” of the MCP process: If there are issues with a Phase I, Tier Classification, or Phase II report, they will spend their time working with the LSP/PRP at that point rather than wait until further in the MCP process. Key Takeaway: Focusing on sites early on allows for course correction so that there is less enforcement at the back end.
  • Striking differences between last year/previous years’ NOAFs and this year:
    • Although AULs are the most common source of audit violations, the common perception is that Nature and Extent is among the most frequent.  However, during this past year only six NOAFs involved Nature and Extent, and among these were a large and complicated MGP residuals site and two roadway spills.
    • Enforcement notices involving Temporary Solution sites did not address Substantial Hazard Evaluations. Practice Tip:  MassDEP confirmed that Substantial Hazard Evaluations are required in conjunction with 5-year Periodic Reviews for those sites subject to Temporary Solution regulations.
    • Of 29 Temporary Solution NOAFs, eight cited no violations – an improvement over the prior year when all 30 NOAFs had cited violations. 
    • No ROS-related notices cited failure to make progress toward a Permanent Solution; the most common ROS violation was failure to report every six months.   MassDEP emphasized that ROS is a subcategory of Phase V, so the PRP needs to actually do something (e.g., sampling, evaluating a new remedy) in the two years following termination of ROS before a Permanent or Temporary Solution Statement is due. If active O&M, then Phase V status reports must be submitted every six months during that period.  Key Takeaway:  Too often there is no action taken following termination of ROS, but unless Phase III or Phase IV activities are re-initiated, there are still Phase V submittal requirements upon ROS termination.   MassDEP often sees PRPs fall off the radar for two years and so MassDEP puts additional requirements on them to submit status reports within those two years.
    • AEPPM telemetry violations emerge – seven NONs for failure to communicate. 

Activity and Use Limitations (AULs)

  • Failure to incorporate an AUL in a new deed is still a recurring theme. There are two ways to do this: a) Confirmatory Deed, or b) Affidavit of Title. 
    • There was quite a bit of discussion about the challenges with AULs because MassDEP does not regulate the real estate community. Key Takeaway:  Need to explain to real estate attorneys the ways in which AULs are different from other deed restrictions. It would be beneficial for MassDEP and the LSPA to have contact with the MA Real Estate Bar Association (REBA), in the form of an in-person event as well as a fact sheet. 
    • MassDEP stated that Anniversary Letters are the only way to track property transfers. Thirty percent of the letters come back as “return to sender.”
  • How many times does one need to pay an AUL fee for the same site, as in the same AUL filed for multiple parcels within one disposal site?  There was some uncertainty about very specific situations but generally the consensus was as follows:  If a condo association owns one property and there are multiple units affected, then one AUL is OK.  Conversely, a PRP needs to pay every time it files an AUL, even if it is the exact same AUL language. If you file more than one AUL for the same RTN, you must pay a fee for each AUL.  The number of lessees doesn’t affect the number of AULs you file.  If you have multiple lessees on a single parcel you only need one AUL, administered by the property owner – not the lessees. Key Takeaway:  A fee must be paid for each AUL to cover costs for MassDEP personnel to review each AUL.  MassDEP said that the different owner issue will be clarified in the revised AUL guidance document.
  • Practice Tip:  MassDEP suggested that LSPs consider the June 2014 Public Review Draft, Guidance on Implementing Activity and Use Limitations, Policy #WSC 14-300, when working with AULs as it reflects MassDEP’s most recent thinking.
  • Regarding the text box noting requirements for future property transfers in the current MCP Word file of Form 1075 [Confirmatory] Notice of Activity and Use Limitation at 310 CMR 40.1009: some LSPs include the text box and some delete it. Practice Tip:  LSPs must include the text box; it is part of the document and is not optional. 
  • How can a utility company know that an AUL exists on a property before they begin to perform utility repairs?  MassDEP reports that there will be more clarity on the upcoming AUL guidance on this topic as well as delineating construction areas, barriers, etc.  They also noted that utility workers are “well-trained” to understand these situations.

Downgradient Property Status (DPS)

  • Does MassDEP pursue a full audit of DPS sites if a flag is raised during an initial screen of the submittal?  Key Takeaway:  A high percentage of DPS submittals get NONs (e.g., 8 out of 9 in 2017 NOAF review).  MassDEP reports that each region has one person who reviews all DPS submittals. 

BWSC Forms and Databases

  • BWSC 111 forms are a useful means of searching for violation resolutions via the file viewer.  Can MassDEP standardize enforcement language to require BWSC111 forms as means of responding to violations? MassDEP says that standardizing the language is  unlikely to happen. Key Takeaway:  Not all NOAFs require use of a particular form when addressing the identified noncompliance, especially when the NOAF has identified noncompliance associated with an AUL.  This is especially true when the required response to the violation does not require an LSP. 
  • Outside of a Permanent Solution, there is no box on a form where you can check that an AEPMM is operating and registered. Some sort of documentation is needed to confirm registration.  Without an AEPMM-specific form, how does MassDEP track AEPMMs other than the ones that register? It would help LSPs to be able to easily find out if a site has an AEPMM (e.g., for a potential buyer or for a proposal for a potential new client). Key Takeaway:  MassDEP tracks AEPMMs internally. MassDEP reports that it is unlikely that they will be able to secure the resources to enable the searchable sites database to identify these AEPMM sites.  However, the information is available.  PSS and TSS forms and RMR forms have a box for AEPMM, so you could find the information if you look for it.

LNAPL Sites

  • Why such a low number of LNAPL sites audited since the 2014 amendments, especially when sites are using the new guidance to achieve Permanent Solutions with Conditions, specifically AULs?   MassDEP notes that there are not a high number of sites meeting the LNAPL requirements and the ones they have looked at are not getting flagged in MassDEP screenings. Key Takeaway:  MassDEP suggested that we will start seeing NOAFs for LNAPL sites, starting with the FY2018 NOAF review.

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AEPMMs and RMRs: What? When? Where? Why?

By Isaac Anderson, Senior Project Manager, Cooperstown Environmental and LSPA Regulations Committee

Though Active Exposure Pathway Mitigation Measures (AEPMMs) are considered exposure mitigation measures and not Remedial Systems, the operation of an AEPMM is still considered a Remedial Action, and as such under 310 CMR 40.0027 requires Active Operation and Monitoring and submission of Remedial Monitoring Reports (RMRs) to MassDEP. The frequency of the RMR submittals varies depending on the conditions being addressed at the disposal site.

For Immediate Response Actions (IRAs), Release Abatement Measures (RAMs), Utility-Related Abatement Measures (URAMs), and Comprehensive Response Actions (CRAs) including Phase IV, Phase V, Temporary Solution, and Remedy Operation Status (ROS), the RMR is to be submitted with the first status report and every six months thereafter. This holds true unless Active Operation and Maintenance was initiated following the submission of the first status report, or Response Actions are being conducted to address an Imminent Hazard (IH) or Condition of Substantial Release Migration (SRM); in those instances other schedules apply.

If Active Operation and Maintenance was initiated after the first status report, and no IH or SRM condition was present at the site, then the first RMR can be submitted with the second status report. If Response Actions were initiated to address an IH or SRM, then RMRs are required monthly following submission of the first status report. Where IRAs are being conducted solely to eliminate, mitigate, or prevent a Critical Exposure Pathway (CEP) that does not pose an IH (even if no IH is present as a result of  AEPMM operation), the frequency of both the Status Reports and the RMRs can be reduced to once annually following:  1) the achievement of No Significant Risk (NSR) for the Receptors of Concern, 2) development of an Operation Maintenance & Monitoring Plan (OM&M Plan) detailing system conditions and operating parameters, 3) a description of the monitoring program to ensure system effectiveness, and 4) an LSP Opinion supporting the reduced reporting schedule, as provided in 310 CMR 40.0425(5).

Notwithstanding any provisions to the contrary, MassDEP may establish Interim Deadlines and alternate schedules for the submission of RMRs.

If you are still reading this article, you may be asking yourself, “Wait, what? Why is the RMR schedule so #%@* complicated?!” and “Is this really merited?” To reduce the tone of outrage in my inner voice at times like these, I tend to seek reason - and sometimes in this industry, it eludes me. In this instance, however, there is a reason, but to get there requires stepping back a bit.

Within the realm of RMRs, there are a lot of similar sounding terms: “Response Action,” “Remedial Action,” “Remedial System,” “Remedial Monitoring Report,” “Active Remedial Monitoring Program,” “Active Operation and Maintenance,” and “Active Exposure Pathway Mitigation Measure,” to name a few. Each of these terms holds relevance to the RMR discussion, but understanding AEPMMs is what really helped me grasp the overarching theme.

AEPMMs is a term that is relatively new to the MCP. While some may believe MassDEP created the term to add to the already torturous number of acronyms belaboring the profession, “AEPMM” was actually created to differentiate between regulatory scenarios. Most of us associate the term AEPMM with the ability to now (since promulgation of the 2014 MCP Amendments) close vapor intrusion sites permanently, but many have likely not considered the importance of creating a new term and including it in other MCP definitions. As noted above, AEPMMs are not Remedial Systems, which is a very important distinction, since sites with Active Remedial Systems are not eligible for Permanent Solution. The term AEPMM was created to differentiate between sites that require ongoing treatment/containment of oil or hazardous material in environmental media (with the use of either Remedial Systems or Active Remedial Monitoring Programs for in situ treatments) and those that have met all other performance standards for MCP closure, excepting exposure prevention measures (which are primarily sub-slab depressurization (SSD) systems). BUT, even though AEPMMs are not Remedial Systems, they are still Remedial Actions that require Active Operation and Maintenance, and hence trigger the need for RMRs. MassDEP has indicated that the definition of RMR will be updated in the upcoming MCP Amendments to make this clearer, along with the RMR provisions in 40.0027. Currently, the definition of Active Operation and Maintenance includes AEPMM operation, but 40.0027 does not mention AEPMM operation; it only discusses remedial actions (wherein AEPPMs are captured), Active Remedial Systems, and Active Remedial Monitoring Programs.

To understand why AEPMM operation requires RMRs, one must look closely at the MCP definitions and the provisions for conducting response actions. By definition, Remedial Action means “any containment or removal;” that’s a broad definition, and in MassDEP’s interpretation it includes the removal of soil gas vapors from beneath a building slab. Within the gamut of response actions, the regulations state that Active Operation and Maintenance of a Remedial Action requires RMR submission. For further clarification on this position, see Section 4.2 of #WSC-16-435, MassDEP’s Final Vapor Intrusion Guidance. 

So, why does MassDEP first separate AEPMMs from Remedial Systems and Remedial Monitoring Programs (by creating the new MCP term “AEPMM”), and then lump them together under the term “Remedial Action”? It’s because maintaining the operation of an SSD system is no less important than the operation of a treatment system or the monitoring of in situ treatment. AEPMMs prevent exposure, typically to human receptors. Until it has been demonstrated with reasonable certainty that a disposal site meets closure conditions now and for the foreseeable future, MassDEP wants periodic information on how the Remedial Action is getting along, and AEPMMs are no exception to that rule. This is further evidenced by the fact that MassDEP requires remote monitoring (telemetry) of AEPMMs upon Permanent Solution, Temporary Solution, or Remedy Operation Status, to ensure their continued functionality.  

Sometimes understanding the basis for a regulation helps me to remember it, other times I just want a “cheat sheet” for its application. For those of you that can relate:

  1. RMRs are required in every possible phase of the MCP where Remedial Actions that require Active Operation and Maintenance or Active Remedial Monitoring can be conducted[1].
  2. When there is a condition that involves sensitive receptors or presents unacceptable risk (IH or SRM/CEP), then at first you must provide an RMR every month starting with the first status report. These scenarios are specific to IRAs because they trigger IRA Conditions. Also specific to IRAs, when you can demonstrate that you have achieved NSR through use of an AEPMM, you can reduce the frequency of both the status report and RMR to once annually until you can close the site.
  3. When the site is not subject to an IRA Condition, Active Operation and Monitoring of the Remedial Actions can be documented in RMRs concurrent with biannual status reports. In that same scenario, if you don’t get an SSDS (AEPMM) installed before the first status report is due, then you can submit the RMR with the next required status report.
  4. Once in Phase V, you continue with whatever RMR schedule applied prior to that until achievement of a Permanent Solution.

(For those of you who do better with visuals and would like yet another MCP flow chart that covers the RMR schedule, please contact me at [email protected] or LinkedIn).

And that’s all there is to it, really - aside from the RMR forms which are a cause for confusion in and of themselves. But, as I understand it, MassDEP intends to update the forms (BWSC 105A and 105B, and 108A and 108B) with the upcoming MCP Amendments, for the sake of clarity.

[1] Limited Response Actions cannot be used to conduct response actions that require Active Operation and Maintenance or Active Remedial Monitoring.

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Review of Vapor Intrusion Notice of Audit Findings, FY 2017

By Jane Parkin Kullmann, Senior Risk Assessor, Wood, and LSPA Loss Prevention Committee

For FY2017, the LSPA’s Loss Prevention Committee reviewed 43 Notices of Audit Findings (NOAFs) from MassDEP (the Department) on the topic of vapor intrusion: 21 from Northeast Region, 14 from Central Region, 7 from Western Region, and 1 from Southeast Region. The number of NOAFs for the Northeast Region is similar to the 19 NOAFs issued relative to vapor intrusion in FY2016.  Of those receiving NOAFs  from the Northeast Region, 11 were also issued a Notice of Noncompliance (NON), 2 were issued an Administrative Consent Order with Penalty (ACOP), and one was issued an NON and then an ACOP.

The most significant issue identified during reviews of vapor intrusion-related NOAFs was the improper operation and reporting of Active Exposure Pathway Mitigation Measures (AEPMMs). Many of the NONs issued for vapor intrusion violations were related to AEPMMs. The most common AEPMM violation was the failure to notify MassDEP of a shutdown test; other violations included AEPMM malfunction (e.g., faulty mechanics or electronics) and failure to notify MassDEP that the AEPMM had a remote telemetry system.  In cases involving shutdown tests, MassDEP required the PRP to follow the relevant steps on the AEPMM guidance web page.  See https://www.mass.gov/service-details/remote-telemetry-for-active-exposure-pathway-mitigation-measures-aepmm. The website lists the steps necessary to select, register, and test an AEPMM, and includes the Telemetry Device Registration Form and a Q&A about remote telemetry.  

Other issues that were addressed in the NOAFs as they relate to vapor intrusion included:

  • The need to address a potential Critical Exposure Pathway (CEP),
  • Insufficient indoor air sampling (e.g., no sampling conducted in the winter months),
  • Termination of Downgradient Property Status because it was not adequately supported by the evidence,
  • Insufficient characterization of nature and extent to define the limits of the Disposal Site, and
  • Issues obtaining site access (which were eventually addressed via the involvement of MassDEP). 

There were also issues identified related to risk assessment and vapor intrusion.  In one case, a risk characterization in support of a Permanent Solution did not evaluate a residential receptor for the indoor air exposure pathway (it evaluated a resident for exposure to soil and a commercial worker, the current use, for exposure to indoor air); therefore, MassDEP said that it was inappropriate to conclude that a condition of No Significant Risk for unrestricted use existed.  In another case, an Activity and Use Limitation (AUL) (with AEPMM) implemented at one property was used to justify a conclusion of No Significant Risk at an adjacent property where the AUL was not implemented.  MassDEP stated that “an AUL imposed on [one property] cannot be used to achieve or maintain a condition of No Significant Risk at [another property], as the owner of that property has no control over the operation of the SSDS.”  In other words, if an SSDS is being used to justify a conclusion of No Significant Risk for a property (even if that SSDS is not located on the subject property), there must be an AUL implemented for that property that documents that fact.

Three examples of NOAFs with NONs relative to vapor intrusion are as follows:

  • An NON was issued to the owner of an industrial site where a historic release of chlorinated volatile organic compounds (CVOCs) occurred. Between 1997 and 2007, trichloroethylene (TCE) was detected in groundwater samples from five monitoring wells at concentrations that exceeded MCP Method 1 GW-2 standards. TCE was also detected in three soil gas samples collected in March 2007. Two of the soil gas samples exceeded the commercial/industrial Sub-slab Soil Gas Screening Value of 130 micrograms per cubic meter (µg/m3). Although TCE was not detected above the analytical Reporting Limit (RL) of 2.68 µg/m3 in two indoor air samples collected in the western wing of the facility in 2007, the RL was above the Department's commercial/industrial Threshold Value of 1.8 µg/m3, and the documentation submitted for this site did not provide adequate information regarding exactly where and how these samples were collected. The evaluation of potential indoor air risks stated that "TCE was not detected in corresponding soil gas indoor air samples," which is an incorrect statement with respect to soil gas. Therefore, because of various uncertainties regarding (a) the current levels of TCE in groundwater, soil gas, and indoor air, particularly within the footprints of the newly constructed buildings; (b) whether the concentrations in any of these media exceed the GW-2 standard and soil gas and indoor air screening values specified above; and (c) whether the thickness of the concrete foundation slabs and moisture barriers constructed at each building location were adequate to block the migration into indoor air of TCE vapors present in soil gas at one or both properties, the Department could not yet concur with the conclusion in the Permanent Solution Statement that a condition of No Significant Risk existed at these properties. To address these issues, MassDEP required that a revised risk characterization and Permanent Solution Statement be submitted once the uncertainties were addressed. 
  • In an NOAF with an ACO and NON issued for a Class A-3 Response Action Outcome (RAO) Statement submitted for a release of CVOCs on commercial and residential properties, MassDEP found that the RAO did not adequately evaluate the extent of releases in all media. Specifically, the vapor intrusion pathway was not adequately evaluated at residential and commercial properties within the site boundaries; the horizontal extent of CVOCs in the groundwater at the site, particularly in the bedrock aquifer, was not adequately evaluated; site activities and uses were not adequately evaluated; Exposure Point Concentrations were improperly calculated; and fencing was used to limit soil exposure to achieve a Permanent Solution.
  • A residential property that eliminated a sump was cited for violations and issued an NON.  The Potentially Responsible Party (PRP) contended that a sump located in the basement of a residence within the site boundary was sealed by the property owner, and that the sealing of this source was not conducted as an MCP response action. MassDEP’s position was that the sealed sump acted as a barrier for the migration of CVOCs into the indoor air of the residence and sealing of the sump was an exposure pathway elimination measure, thereby requiring an Activity and Use Limitation (AUL). However, an AUL was not filed for the property. MassDEP required the PRP to retract the Class A-3 RAO and terminate three AULs that were previously recorded because they either restricted a current use or relied upon a fence to limit exposure and achieve a Permanent Solution. 
Conclusion

Overall, no specific patterns of noncompliance related to vapor intrusion were identified during this review. However, as more and more disposal sites rely on AEPMMs to address a vapor intrusion pathway to achieve a Permanent Solution, more MassDEP audits will likely be conducted to assess AEPMM compliance.  Vapor intrusion cuts across many other response action areas, including nature and extent evaluation, risk characterization, application of remedial additives, and requirements for Temporary and Permanent Solutions. Accordingly, it is important that LSPs stay up to date and understand the latest regulations and guidance and how they relate to the vapor intrusion pathway.  Furthermore, MassDEP’s VI Guidance can be useful when considering sampling needs related to a potential VI pathway and what reporting limits should be achieved when collecting these samples.

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LSPA Members - Please Update Your Website Profile

 

The LSP Association (LSPA) has revamped its Find an LSP page on the LSPA website. People browsing the LSPA website will have the ability to search the LSPA member directory to find an LSP or other environmental professional who meets their needs. Searches can be conducted on the following entries: specialty field, last name, company name, city or zip code (up to 100 mile radius of a given zip).
 
This change is recent and the options for specialty fields have been updated. Please confirm your LSPA profile is up to date. Click here for instructions on updating these fields in your profile. Updating your profile will make it easier for potential clients,  colleagues, and others to find you.
 
As a result of this change, the complete LSPA membership list is no longer available to the general public. However, that information is still available to members through the members page. Instructions can be found here.   

If you have any questions or concerns about the recent changes, please email [email protected]. 

Risk Characterization Findings From Fiscal Year 2017 NOAF Review  

By Crista J. Trapp, Human Health Risk Assessor, The Vertex Companies, Inc. and Chair, Loss Prevention Committee  

The LSPA’s Loss Prevention Committee (LPC) continues its annual review of Notice of Audit Findings (NOAFs) issued by the Massachusetts Department of Environmental Protection (MassDEP) with a review of NOAFs that discuss risk characterization. The Massachusetts Contingency Plan (MCP) allows remediation decisions to be based on the risk posed by site conditions, as opposed to requiring cleanup to background or numerical standards in all instances. Accordingly, it is extremely important that Licensed Site Professionals (LSPs) provide risk characterizations that are sufficient to support site cleanup decisions and, with respect to those associated with Permanent Solution Statements (PSS), adequately support the conclusion that site conditions are protective of health, safety, public welfare, and the environment. We provide this summary of the issues identified in the Fiscal Year (FY) 2017 NOAF review related to risk characterizations in the hopes that Notices of Noncompliance (NONs) might be avoided.

The LPC reviewed a total of fourteen NOAFs and one Administrative Consent Order (ACO) that were categorized as pertaining to risk characterization.  Of the fourteen NOAFs, all received NONs. Similar to last year’s review of risk characterization-related NOAFs, the most frequent violations were related to Site Information Required for Risk Characterization (310 CMR 40.0904), Identification of Exposure Points (310 CMR 40.0924), and Calculation of Exposure Point Concentrations (310 CMR 40.0926). New for FY 2017 were violations related to Characterization of Risk to Safety (310 CMR 40.0960). In addition to these four most frequent violations categories, at least ten other violations pertaining to various risk characterization components of the MCP were identified.  Please note that this article describes issues identified by MassDEP; the LPC author has not independently reviewed the underlying documents.

  1. Site Information Required for Risk Characterization (310 CMR 40.0904)

The accuracy and weight of the conclusions of a risk characterization depend on a complete definition and delineation of the nature and extent of a release and full consideration of relevant media and migration pathways. Four NONs and one ACO were issued due to failure to define the extent of the release or failure to adequately characterize the Disposal Site.

One NON was issued for a Class A-1 Response Action Outcome (RAO) submitted in April 2012 that documented the cleanup of a release of diesel fuel. The conclusion that site conditions were consistent with background and thus met a condition of No Significant Risk was based solely on visual observations. Although applicable for some sites, such as those with small spills that are distant from a surface water body, the sole use of visual observations to conclude conditions were consistent with background was found by MassDEP to be a violation of 310 CMR 40.0904(2)(c), which requires the collection and analysis of surface water and/or sediment samples to verify that concentrations of site contaminants would not result in surface water or sediment concentrations of potential ecological significance.

Another NON was issued for a revised Phase II Comprehensive Site Assessment (CSA) submitted in October 2016 (after a July 2016 NON) that failed to evaluate the potential human health risks from direct contact with coal tar/NAPL and other waste materials present at the Disposal Site. As documented, the PRP had placed 4 to 5 inches of compacted asphalt millings over an area to create a temporary barrier to coal tar seeps. Nonetheless, active tar seeps were observed by MassDEP at the onset of warm weather. Additional cover material was then placed to prevent workers from contacting the liquefied coal tar. However, based on MassDEP’s observation of the continuing active coal tar seeps and what was presented in the Revised Method 3 Risk Characterization, MassDEP found that potential exposures to coal tar/NAPL wastes were significantly underrepresented by the soil analytical results used in the derivation of Exposure Point Concentrations (EPCs). Therefore, MassDEP concluded that risks to current and future commercial and construction workers from exposure to coal tar/NAPL wastes at the Disposal Site could be significant if direct contact with the wastes was not prevented.  As such, the seeps cannot only be considered a public welfare nuisance under 310 CMR 40.0994, as the Revised Phase II CSA suggested, but must also be evaluated in the human health risk assessment. As set forth in the MassDEP Office of Research and Standards (ORS) Memorandum attached to the NON, risk of harm to human health from exposure to wastes encountered throughout the Disposal Site, including the coal tar seeps, must be addressed in the risk assessment process.

A third NON was issued for a Partial Class A-3 RAO submitted in June 2009 for releases associated with a 10,000-gallon fuel oil underground storage tank (UST) and historic commercial laundry wastewater discharges to drainage troughs. According to the NON, soil concentrations exceeded the S-1/GW-2 Method 1 Standards for extractable petroleum hydrocarbon (EPH) carbon fractions where a potential vapor intrusion pathway into the existing building may exist. Additionally, soil samples from these soil borings were not analyzed for volatile organic compounds (VOCs), which were identified as contaminants of concern (COCs) at the Disposal Site, and the Method 3 Risk Characterization did not evaluate the potential vapor intrusion pathway for petroleum constituents. MassDEP required additional corrective actions.

The fourth NON pertaining to 310 CMR 40.0904 was issued for a Class A-3 RAO submitted in December 2012 for a site in a GW-1 area. MassDEP noted that the COCs identified at the Disposal Site were EPH and volatile petroleum hydrocarbons (VPH), and that soil and groundwater samples obtained from the site were analyzed by MassDEP EPH and VPH methods. However, Environmental Protection Agency (EPA) Methods 524.2 and 525.2 were used to analyze residential tap water samples to determine if nearby private drinking water wells had been impacted by site contaminants. Neither of these EPA Methods will quantify site COCs (e.g., EPH and VPH). Subsequently, MassDEP concluded that no data had been acquired that would support the conclusion that the site does not pose a significant health risk to nearby residents that use private drinking water supplies. Further, MassDEP stated that several wells at the site were not optimally located to identify potential contaminant migration from wells that have exceedances of one or more GW-1 Standards. Additionally, groundwater samples obtained from one well exhibited concentrations of C11-C22 aromatics at approximately twice the GW-1 Standard. The presence of this contaminant at this location indicated (1) that groundwater flow may be radial and (2) that concentrations of contaminants in excess of GW-1 Standards may extend downgradient of the Disposal Site.

The ACO that was issued identified deficiencies pertaining to 310 CMR 40.0904.  The ACO was for a Class A-3 RAO submitted in June 2010. The site had been in industrial use since the 1800s, and more recently had been used for manufacturing metal-coated products for the electronics industry during which chlorinated volatile organic compounds (CVOCs), metals, petroleum hydrocarbons, and cyanide were released, including the improper disposal of hazardous waste sludge into a lagoon in the early 1980s. The lagoon was reportedly closed in 1981. In June 2013, a NON was issued as a result of an audit that included a site inspection in May 2011, a request for additional information following the site inspection, and a review of the 2010 Class A-3 RAO.  In the ACO, dated October 6, 2017, which appears to have resulted when the NON went unaddressed, MassDEP determined that the vapor intrusion pathway had not been adequately evaluated at residential and commercial properties within the Disposal Site boundaries. Also, the horizontal extent of CVOCs in groundwater at the Disposal Site, particularly in the bedrock aquifer, had not been adequately delineated. The ACO required retraction of the Class A-3 RAO and submittal of a Tier Classification, termination of the three Activity and Use Limitations (AULs), and completion of a Phase II CSA and subsequent required reports.

2. Identification of Exposure Points (310 CMR 40.0924)

Two NONs were issued due to the failure to identify appropriate exposure points. In accordance with the MCP, all potential exposure points must be identified and described in the documentation of the risk characterization. In a Method 1 or 2 risk characterization, soil exposure points must be defined by the horizontal and vertical distribution of the contaminated soil in combination with the applicable soil categories.  

Both NONs identified a violation of 310 CMR 40.0924(2)(a)2 due to the inclusion of soil samples collected from outside the extent of the soil contamination as part of a soil exposure point. Thus, the resulting EPCs were diluted with lower concentrations and were not representative of the concentrations of COCs to which a receptor may be exposed.

In addition, one of the NONs identified a violation of 310 CMR 40.0924(1). The risk characterization evaluated a single exposure point for soil; however, the site data indicated that soil contamination was present at depths both shallower and greater than 15 feet. MassDEP stated that although current use may warrant use of a single soil exposure point for soil, evaluation of unrestricted future site use requires evaluation of two soil exposure points: S-1 for less than 15 feet and S-3 for greater than 15 feet.

3. Calculation of Exposure Point Concentrations (310 CMR 40.0926)

Comprehensive and careful analysis of the data is required to develop appropriate EPCs. In developing an EPC, the objective should be to identify a conservative estimate of the average concentration that could be contacted by a receptor at the exposure point over the period of exposure. The method used for calculating EPCs should also be clearly stated. MassDEP’s Guidance for Disposal Site Risk Characterization (WSC/ORS-95-141) provides specific direction on developing EPCs, including consideration of spatial and temporal averaging, determining when average concentrations are not appropriate, and addressing hot spots.

There were three NONs and one ACO with violations of 310 CMR 40.0926 in the FY 2017 NOAFs.

One of the NONs had a violation of both 310 CMR 40.0926(3)(b)&(c) and 310 CMR 40.0926(3). In the NON, MassDEP stated that the PSS, submitted in December 2016, failed to include justification for using the average concentration as the EPC for C9-C10 aromatic hydrocarbons when 75% of the data points used in the averaging procedure were not equal to or less than the applicable standard or risk-based concentration limit and the maximum detected value was not less than ten times the applicable standard or risk-based concentration limit. The use of a maximum concentration or the 95% upper confidence limit on the mean, whichever is lower, must be used to estimate an EPC when the above criteria are not met unless valid justification is provided.

Additionally, the EPCs for groundwater were developed by calculating a temporal average concentration in each well using data obtained in 2008, 2014, and 2016. MassDEP stated that the data set used in the risk characterization did not represent a conservative estimate of the mean for two reasons: 1) an average of three data points obtained over a time span of eight years is not representative of the current concentration that may be contacted by a receptor, and 2) not all of the available VPH data reported to MassDEP for the subject property were used in the evaluation.  MassDEP noted that groundwater samples had been independently collected and analyzed for petroleum analyses from the monitoring well network upgradient by a different PRP.  The resultant chemical data had been submitted to MassDEP, were available in the public file, and were transmitted to the PRP via two Notices of Environmental Sampling.  All available relevant chemical data that are representative of site conditions at the time of the risk characterization must be included in the evaluation of disposal site risk unless they meet the criteria for exclusion.

Another NON was issued for failure to identify and document an EPC for each COC in each medium at each exposure point. In the risk characterization used to support the PSS, evaluation of the current vapor intrusion pathway at the site was based solely on indoor air concentrations estimated from soil vapor data (using MassDEP's dilution-attenuation factor of 70) due to the operation of an active dry cleaner at the site. The risk characterization predicted an indoor air concentration of tetrachloroethylene (PCE) of 13.2 µg/m3 and concluded that there was no current risk for workers at the dry-cleaner. EPCs for indoor air exposure were not developed for a future residential exposure scenario, and thus the vapor intrusion pathway for potential future use of the property for residential purposes was not evaluated.  Further, future residential use of the property was not restricted by an AUL. MassDEP used the PCE EPC of 13.2 µg/m3 and its Shortform for residential indoor air and estimated an Excess Lifetime Cancer Risk of 1.7E-5, which exceeded the MCP risk limit of 1E-5.  To address this deficiency, MassDEP required revision of the risk characterization and/or implementation of an AUL at the site.

The third NON, which has been previously discussed in Section 1, failed to identify a conservative soil EPC for potential exposure to coal tar/NAPL wastes.

The ACO that was issued pertaining to 310 CMR 40.0926, which was previously discussed in Section 1, included the failure to identify a conservative estimate of the average concentrations. The EPCs provided in the Method 3 Risk Characterization for COCs in groundwater were calculated as an average of the individual temporal averages for individual wells on the downgradient property, which is not an appropriate method for identifying groundwater EPCs.

4. Characterization of Risk to Safety (310 CMR 40.0960)

There were four violations of 310 CMR 40.0960 in the FY 2017 NOAFs. Three of the four NONs were issued for the failure of the PSS risk characterization to include an evaluation of the potential risk to safety. For the fourth NON, MassDEP identified a violation of 310 CMR 40.0960 because the Phase II CSA risk characterization did not include an evaluation of the potential risk to safety due to the presence of rusted and corroded drums observed by MassDEP at multiple locations at the site.

5. Conclusion: Include Your Risk Assessor in the Planning Stages!

For any project that seems likely to involve the MCP, involve a risk assessor at the scoping and investigation stage of the project to assist with MCP compliance and closure strategy. When a property becomes a Disposal Site, MCP closure should be the focus from the beginning. A risk assessor can help design a sampling plan that will generate a robust and representative data set for evaluating potential remediation needs and that can later be used to perform EPC calculations to achieve MCP closure. Furthermore, a risk assessor can quickly identify when important components of a risk characterization are missing, such as the evaluation of the potential risk of harm to safety, as required by the MCP. 

Reclamation Soil

By: Jenni Wharff, Environmental Analyst, Audits and Enforcement, MassDEP BWSC

(The LSP Association does not edit any articles submitted on behalf of any government agency or the LSP Board, other than for formatting purposes.) 

You are an LSP managing soils under a Release Abatement Measure or simple construction activities. You have 150 cubic yards of soil that cannot be re-used at the site. You’ve characterized the soil and know the nature and extent of contamination present on the property, if any. The 150 cubic yards you’ve analyzed is less than Reportable Concentrations (RCs). It’s not hazardous so you don’t want to ship the soil out-of-state at substantial cost.  How can this soil be used? Where can the soil go? Thanks to Section 277 of the FY2015 Budget you now have the option to send this soil to a COMM-15-01 soil facility!

What is COMM-15-01? COMM-15-01 is the Interim Policy on the Re-Use of Soil for Large Reclamation Projects. This policy was implemented pursuant to Section 277 of the FY2015 state budget (chapter 165 of the Acts of 2014), which mandated that the Department establish regulations, guidelines, standards or procedures for determining the suitability of soil used as fill material for the reclamation of quarries, sand pits and gravel pits, and that the re-use of this soil poses no significant risk of harm to health, safety, public welfare or the environment.

Massachusetts has seven (7) Reclamation Soil facilities currently accepting soil.  Each of the facilities operates under an Administrative Consent Order (ACO), negotiated by regional MassDEP staff, with input from appropriate municipal officials. MassDEP will not finalize an ACO until all comments from local officials on project impacts related to noise, dust, odor and/or trucks have been addressed by the project proponent.  The ACO with a MassDEP approved Soil Management Plan (SMP) functions as a permit for the facility.  Reclamation Soil facilities qualify for the MCP notification exemption at 310 CMR 40.0317(13) for approved facilities, meaning Reclamation Soil facilities operating within the requirements of their ACO provide a level of comfort for generators that facilities operating “at risk” cannot.

The ACO will also stipulate the inspection, monitoring, and reporting requirements for the operator of the Reclamation Soil facility.  An example of some items that must be included in an SMP are project overview, purpose and goals, total volume of fill proposed, site description of current conditions (sensitive receptors and regulatory history) and site soil and groundwater reporting categories, including rationale for those reporting categories and developed Soil Acceptance Criteria (SAC), and proposed post closure use. These are few examples of what criteria can be included in the SMP but not all (see the link below for more information, including links to current ACOs/SMPs). The ACO and the SMP combined will make up a complete Reclamation Soil facility ACO.  

There are three facilities approved in MassDEP’s  Central region, one in Northeast and three in the Southeast region. For a more detailed description of each of these facilities or more details about the requirements of Reclamation Soil please visit https://www.mass.gov/soil-transport-re-use-and-disposal

How does the generator of soil know if soil from a project is appropriate for re-use at a Reclamation Soil facility?

The generator of the soil must properly characterize the soil. An LSP will be tasked with documenting compliance with the testing protocols and acceptance criteria as developed by MassDEP. The generator and the generator’s LSP will then complete a generator analytical profile. Generator analytical profiles are similar to profiles developed for soils to be sent for asphalt batch recycling but with a very important difference. The generator soil must not be considered hazardous waste, remediation waste, or contain solid waste as those terms are defined in 310 CMR 40.0006. The generator analytical profile must be sent to the Reclamation Soil facility’s LSP for review and rejection or acceptance of the generator soil.  Generator applications must give specific details as to where the soil was generated - meaning, historical property operations and or information regarding RTNs at the Site which properly characterize the boundaries of contamination at the soil generator property.

For example, an LSP has naturally deposited soil that has been excavated and can’t be re-used at the origin property. Based on the information provided in that facility’s SMP, characterization of naturally deposited soil will require a soil sample for every 1,000 cubic yards of soil to meet the SAC for this facility. The soil samples must be analyzed for certain parameters:

  • Field Screening for Total Organic Vapors
  • Volatile Organic Compounds (EPA 8260)
  • Semi-volatile Organic Compounds (EPA 8270 full list)
  • Metals – MCP 14 metals (EPA 6010/7000)
  • PCBs (EPA 8082)
  • Total Petroleum Hydrocarbons (summation of EPH/VPH Fractions can be substituted by MassDEP Methods)
  • Hexavalent Chromium if total Chromium > 100 mg/kg (EPA 7196A)
  • pH/Corrosivity (150.1/SM-4500H+ B/9040/9045)
  • Herbicides and Pesticides (may be excluded or limited based on site history) (EPA 8151 and EPA 8081 respectively)
  • Iginitibility/Flash point (may be excluded or limited based on site history)
  • Reactive Sulfide (may be excluded or limited based on site history)
  • TCLP for any analyte exceeding EPA TCLP Trigger Values (EPA Method 1312)
  • If blasted/excavated bedrock is accepted – A Net Acid Generation test
  • Other tests as deemed prudent by the LSP based on soil source location history.

Testing requirements for soil being sent to a COMM-15 facility requires soil samples to be analyzed for MCP-14 metals, whereas soil to be sent to asphalt batching facilities requires RCRA-8 metals analyses. Be sure to give care to the proper testing requirements that the SMP dictates for that specific Reclamation Soil facility. Testing up front for MCP-14 metals will allow greater flexibility for where the soil can go.

Additionally some facilities are located in RCS-1 areas and this allows them to only accept soil less than RCS-1. Some facilities may accept up to RCS-2 due to the physical setting where the facility is located.  Each Reclamation Soil facility will use these RCs as a starting point, but will develop their own soil acceptance criteria unique to that facility. Some SAC are set well below the applicable RCs. It is very important to understand what a Reclamation Soil facility’s criteria are before sending the soil.

Another item to keep in mind when analyzing generator soils is laboratory reporting limits. There are no universal SAC for all of the Reclamation Soil facilities. In reviewing the seven reclamation soil facilities currently approved, it can be seen that they utilized MassDEP’s WSC#13-500 guidance to develop their acceptance criteria. Most, but not all of the Reclamation Soil facilities utilize 10% of the RCS-1 or RCS-2 values as their soil acceptance criteria for VOCs and SVOCs, and ½ the RCS-1 value for TPH. Many of these values are very small. To ensure that soil is not rejected it is important to let the laboratory know to use these smaller values.

These are some highlights from three successful years of Reclamation Soil facility operations. If you believe you would qualify as a Reclamation Soil facility operator or have soils that would be appropriate for some of the facilities please go to our new website https://www.mass.gov/soil-transport-re-use-and-disposal and contact your local MassDEP regional office to review available options.

This article provides a broad overview, and there are important nuances to be found in the requirements, guidance, ACOs and SMPs, that are applicable to soil management.

COMM-15-01 was developed as a tool to ensure safe, smart, and viable alternatives for soil re-use in the Commonwealth.

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New EPA BaP Tox Values on Remediation of PAH Sites

By Amy B. Rosenstein, Risk Assessment and Toxicology Consultant, Lexington Environmental Risk Group, LLC and LSPA Technical Practices Committee

In January 2017, the U.S. Environmental Protection Agency (USEPA) released new toxicity values for benzo(a)pyrene (BaP)[1] based on new toxicological evidence; thus, risk-based cleanup goals for hazardous waste sites with PAHs will change.  These changes do not just apply to sites contaminated with BaP, but also to sites with a variety of other PAHs for which toxicity is evaluated relative to BaP.  The new BaP toxicity values will almost certainly have an impact on cleanup decisions at sites contaminated with PAHs.  

The new BaP cancer slope factor is approximately 7 times less stringent than the previous one.  This less stringent slope factor will decrease the estimated oral, dermal, and inhalation cancer risks of BaP and other carcinogenic PAHs for which BaP is a reference chemical. Therefore, the author expects that:

The new cancer toxicity value for BaP will decrease the necessity for cancer-risk-based site cleanups based on BaP and other carcinogenic PAHs for which risks are evaluated relative to BaP.

On the other hand, USEPA has also published non-cancer oral and inhalation toxicity values for BaP for the first time (although substitute non-cancer values have previously been applied by the Massachusetts Department of Environmental Protection [MassDEP] for BaP and other PAHs), which may drive additional cleanups at some sites.  In fact, US EPA Region 3 has already published air risk-based regional screening levels (RSLs) for BaP that are more stringent than the previous air RSLs.[2]  In addition, revised USEPA Region 3 RSLs for PAHs in soil, air, and water have already been published (first in June 2017, and more recently in November 2018).

Therefore, the author expects that:

When BaP is detected at a site and inhalation exposures are important, the calculated non-cancer risks for BaP may increase, resulting in more site cleanups.

MassDEP is in the process of drafting new Method 1 standards for PAHs, as part of MCP amendments that will be released this year.  According to MassDEP at a recent BWSC Advisory Committee meeting, once the draft amendments are completed and released, a public comment period of 2 to 3 months will follow, along with 3 or 4 public hearings.  MassDEP then reviews the comments, and revises and publishes the final regulations; thus, MassDEP expects that it will be at least 6 months from release of the draft amendments until the regulations are final. 

There are certainly outstanding questions related to the publication of USEPA’s new toxicity values and risk-based screening levels for BaP.  These outstanding questions, and the author’s thoughts on what the responses might be, are as follows:

  • Will the new BaP cancer toxicity value change state cleanup levels for PAHs at hazardous waste sites? Yes, most likely, but so far few states have promulgated changes (e.g., the Michigan Department of Environmental Quality and the Indiana Department of Environmental Management), although changes may be phased in over time.
  • Will the new BaP non-cancer inhalation toxicity value affect future PAH-based cleanups at hazardous waste sites?  Possibly yes, but the direction of the cleanup (more or less conservative) will likely depend on whether or not inhalation exposures to dust or vapors containing BaP are important pathways.
  • Will the publication of the new BaP toxicity value change previous remedies?  Unknown, but it could affect remedies currently in the process of being decided upon and will certainly affect future MCP Method 1 and Method 3 risk assessments.

It will be interesting to see what happens in the next few years with respect to PAH-contaminated sites in Massachusetts, as well as in other states.

Case Studies

The following case studies illustrate potential changes in risk management outcomes that could occur due to the BaP toxicity value revisions.

Case Study 1:  PAHs in soil--residential scenario--oral and dermal contact

PAH concentrations in surface soil at Whitney Property (from Baseline Human Health and Ecological Risk Assessment, Volume I, Southwest Properties, Wells G&H Superfund Site, Operable Unit 2, Woburn, Massachusetts, March 2014, TRC Environmental) were used by the author of this article as an example to evaluate risks due to residential soil contact.  With the new toxicity values, the author estimates that calculated site risks would change as follows:

  • Estimated cancer risks decrease to a level below 1 x 10-5 (one in one hundred thousand), the MCP acceptable incremental risk level, so that cleanup of PAHs in soil on this site would not be required to protect public health.
  • The non-cancer risks increase, based on the more stringent non-cancer toxicity values, although for these particular soil data, they are not above the MassDEP hazard index limit of 1 for non-cancer risks.

Using old toxicity values:

Cancer Risk (all chemicals) =

6.2 x 10-5

Chronic Non-Cancer Hazard Index (all chemicals) =

0.023

Subchronic Non-Cancer Hazard Index (all chemicals) =

0.0052

Using new toxicity values:

Cancer Risk (all chemicals) =

8.4 x 10-6

Chronic Non-Cancer Hazard Index (all chemicals) =

0.13

Subchronic Non-Cancer Hazard Index (all chemicals) =

0.032

Case Study 2:  Hypothetical site with PAHs in groundwater--construction worker--incidental ingestion, dermal contact, inhalation

The author of this article estimated risks for a construction worker exposed to groundwater during outdoor excavation work which could occur, for example, at a new construction site or digging a utility trench. Hypothetical groundwater concentrations and estimated air concentrations were used in combination with the new toxicity values. Findings indicate that:

  • Estimated cancer risks decrease to a level equal to the allowable MassDEP incremental cancer risk limit, meaning site cleanup based on cancer risks would now not likely be required.
  • But it is a different story for non-cancer health effects, since non-cancer risks for this chemical and the related PAHs were previously not evaluated,[3] resulting in a non-cancer hazard index less than one.  Applying the new non-cancer oral toxicity value for BaP results in a hazard index greater than 300 for these pathways.  Clearly, in this case, mitigation measures for construction worker contact with groundwater would need to be considered.

Using old toxicity values:

Cancer Risk (all chemicals) =

7 x 10-5

Non-Cancer Hazard Index (all chemicals) =

0.0005

Using new toxicity values:

Cancer Risk (all chemicals) =

1 x 10-5

Non-Cancer Hazard Index (all chemicals) =

312

 

Note:  Thanks to Julianna Connolly, LSP (Green Ladder Environmental, LLC) and Jane Parkin-Kullmann, Senior Risk Assessor (Wood PLC) for reviewing an earlier draft of this article.

[1] BaP is a polycyclic aromatic hydrocarbon (PAH) that is known to cause both cancer and non-cancer health effects.

[2]  For PAHs other than BaP, non-cancer inhalation, dermal and ingestion risks will continue to be evaluated using their chemical-specific non-cancer toxicity values, as was done previously.

[3] Since there were no published USEPA non-cancer toxicity values for BaP.

 

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