July 2020

In This Issue

The LSPA would appreciate your feedback on the articles included in the July 2020 newsletter. Please send your comments and questions to [email protected].

President's Message 

Greetings to everyone in this physically distant and new "normal" time. It is an understatement to say that A LOT has changed since the last LSPA newsletter.  

I hope you enjoy the articles below and find them helpful to your practice. The first newsletter article highlights Method 533 - the new EPA method for analyzing PFAS in drinking water. Released in December 2019, this method includes some significant improvements over the existing EPA PFAS drinking water procedure, Method 537.1. 

The remaining four articles were authored by members of the LSPA's Loss Prevention Committee (LPC). Each year the LPC searches the eDEP files, downloads and visually scans Notices of Audit Findings (NOAFs) and Administrative Consent Orders (ACOs) and organizes them in broad topical practice categories for review by committee members. These members pour over these documents, have intense and fascinating committee discussions, and resurface with written lessons learned and common areas of deficiencies. This information is shared in newsletter articles containing a wealth of valuable information for all practitioners. I strongly encourage you to read the work of the LPC below and share these important practice tips with your colleagues. Kudos to LPC for continuing to do this detailed and thorough research and review annually! 

Before you get to the articles, I'd like to draw your attention to the LSPA Blog, called LSPA News & Blog on the homepage of our website. The blog includes up-to-date information from the LSP Board of Registration and MassDEP such as New Information from LSP Board on License Renewals and Recent Massachusetts Executive Orders. Also posted in the past month was Upcoming Changes to NPDES Application Process and NOI Submittals to MassDEP. In addition, we are pleased to share a 20-minute video created by The Vertex Companies, Inc., that shows how to get your home workspace set up for ergonomic success. Thank you Vertex. I learned alot from this  - EEEK - and now need to implement some changes. No wonder my back hurts! 

I encourage you to check out the LSPA website and blog regularly. Click here for past blog posts and visit the LSPA website regularly for new postings

On behalf of the LSPA Board and staff, I wish you all good health.
Be safe.


Michele Paul, LSP, President

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PFAS Analysis of Drinking Water by EPA Method 533

By Jim Occhialini, Vice President, Alpha Analytical, and LSPA Technical Practices Committee


This new Per- and Polyfluoroalkyl Substances (PFAS) analytical method was released by the U. S. Environmental Protection Agency (EPA) in December 2019; it includes some significant improvements over the existing EPA PFAS drinking water procedure, Method 537.1. 

There are two primary procedural differences between the two methods:

  1. Method 533 incorporates the use of extracted internal standards as part of an isotopic dilution quantification approach whereas Method 537.1 does not. The use of the isotope dilution technique reduces the overall uncertainty associated with the analysis. 
  2. Method 533 uses a weak anion exchange (WAX) solid phase extraction (SPE) cartridge instead of the polystyrene divinylbenzene (SDVB) used in Method 537.1.  The use of the WAX SPE cartridge in Method 533 allows for additional PFAS compounds to be determined, particularly short chain PFAS not amenable to Method 537.1 analysis.

Method 533 lists 25 PFAS compounds that can be analyzed and Method 537.1 lists 18 PFAS compounds. It should be noted that not all 18 of the Method 537.1 compounds can be determined by Method 533, even though it has a 25-compound list. The Method 533 list contains 14 Method 537.1 compounds, plus 7 additional compounds that are on U.S. Department of Defense (DoD) and other compound lists, as well as 4 totally new PFAS compounds that were previously not on any PFAS analytical list.  Therefore, the maximum number of PFAS compounds that drinking water can be analyzed for using both Method 537.1 and Method 533 is 29. It should be noted that the 6 PFAS compounds listed in the updated December 2019 MCP Method 1 standards and the proposed Massachusetts MCLs are included in both methods, the new Method 533 and Method 537.1.  Please see the EPA table that lists the PFAS compounds amenable to each drinking water method.

Another significant difference between the two methods is the holding times required by each. Method 533 allows for 28 days to extraction and another 28 days to analyze, whereas Method 537.1 only allows 14 days to extraction and another 28 days to analyze.  There are different preservatives used as well: ammonium acetate is used for Method 533 and Trisma® is used with Method 537.1.

Method 537.1 and Method 533 are primarily limited to clean water applications. For all other cases, where non-potable water, soils, or tissues need to be analyzed, another analytical method will need to be utilized. This is also the case when there are additional specific PFAS compounds that need to be included that are not on either method’s target compound list.  Given that Method 533 has just been released, it may not yet be available for laboratory certification in specific states; practitioners interested in using this method for drinking water compliance in a specific state should inquire about laboratory certification status.   

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Temporary Solutions: 2018-2019 NOAFs and Draft MCP Amendments 

 By James H. Zigmont, LSP, P.G., CDM Smith, and Loss Prevention Committee

The Loss Prevention Committee’s review of enforcement notices involving Temporary Solutions from fiscal years (FY) 2018 (July 2017 through June 2018) and 2019 (July 2018 through June 2019) identified 23 disposal sites in each of the two fiscal years that were recipients of Notices of Audit Findings (NOAFs), Notices of Noncompliance (NONs), or Administrative Consent Orders with Penalties (ACOPs). As in FY 2017, some NOAFs found no violations relating to sites with Temporary Solution status. For FY 2018, five of the 23 notices identified no violations; for FY 2019, there were nine notices involving no violations. There were eight such notices out of 29 Temporary Solution sites reviewed for FY 2017.

As part of its review of NOAFs, the Committee looks for possible enforcement differences among the MassDEP regions. A review of the number of enforcement notices involving Temporary Solution sites as performed by MassDEP regions is summarized as follows:

Temporary Solution
Enforcement Notices


1 – WERO

2 – CERO

3 -- NERO

4 – SERO

























Remarkably enough, the number of enforcement notices for each of the past two years is identical for each of the four MassDEP regions. Differences among the regions in FY 2017 and FY2016 can be explained in part by the issuance of NONs as form letters for failure to submit 5-year Periodic Reviews by Western Region (FY2016) and Northeast Region (FY2016 and FY2017). Similar form letters were not issued by any of the regions in FY2018 and FY2019. Aside from these statistics, there were no regional patterns of MassDEP review that could be termed substantive. 

Consistent with past years, the most typical violations in FY2018 and FY2019 involved the failure to maintain compliance with Post-temporary Solution regulations. For FY2018, 11 of the 18 sites cited for violations fall into this category; for FY2019, 10 of the 14 sites cited for violations similarly were in non-compliance with Post-temporary Solution regulations. Violations included failure to submit Post-temporary Solution Status Reports (310 CMR 40.0898), Remedial Monitoring Reports (310 CMR 40.0898), and 5-year Periodic Reviews (310 CMR 40.1050(4)(b)). A number of NONs cited the failure to perform Post-temporary Solution operation, maintenance, or monitoring as proposed in the Temporary Solution Statements.  

Earlier MassDEP presentations forecasting the now‑issued 2019 Proposed Amendments to the Massachusetts Contingency Plan (MCP) indicated that the Department recognizes the challenges of the current Temporary Solution regulations, and that they are the basis for a wide variety of response actions with different objectives.   The Committee’s experience in reviewing audit findings is that there is a recurring set of Temporary Solution regulations subject to common non-compliance. These are summarized as follows:

  • 310 CMR 40.0560: Response Action Deadlines and Requirements for Tier Classified Disposal Sites – general Tier Classification requirements not specific to Temporary Solution status but cited for those instances where Post-temporary Solution remediation is performed without active Tier Classification status.
  • 310 CMR 40.0897: Post-temporary Solution Operation, Maintenance and/or Monitoring – requirements by which operation, maintenance, and monitoring of a Comprehensive Remedial Action must be performed following submittal of a Temporary Solution Statement, including a reference to reporting obligations.
  • 310 CMR 40.0898: Post-temporary Solution Status and Remedial Monitoring Reports – reporting obligations for those Temporary Solution sites that are performing Active Operation and Maintenance (O&M).
  • 310 CMR 40.0956: Substantial Hazard Evaluation – requirements for determining a condition of No Substantial Hazard in support of a Temporary Solution Statement.
  • 310 CMR 40.1050: Temporary Solutions – general requirements for achievement of Temporary Solution status. 
  • 310 CMR 40.1067: Remedial Actions After a Permanent or Temporary Solution Statement has been Submitted to the Department – specific to Temporary Solutions, Post-temporary Solution remedial actions must be conducted under a valid Tier Classification or Extension thereof (310 CMR 40.1067(7)).

Not addressed in the above citations is the requirement that every 5-year Periodic Review (310 CMR 40.1050(4)(b)) include an update of the Substantial Hazard Evaluation. Indeed, this requirement is not directly stated anywhere in the MCP, either in current or proposed amendment versions, but is sometimes cited in audit findings.  Its requirement is based on the definition of a Substantial Hazard Evaluation, which includes an assessed exposure period from the time of notification to 5 years into the future (310 CMR 40.0956(1)(b)). There were no such violations cited in the FY2018 enforcement notices and only one in FY2019. However, there were numerous instances of failure to submit a 5-year Periodic Review during both fiscal years.

A key element to compliance, under both the current MCP and the proposed amendments, is proper management of Active O&M performed as Post-temporary Solution response actions. For Post-temporary Solution compliance, Active O&M, regardless of the objective of the Temporary Solution, i.e., a Permanent Solution or maintenance of a condition of No Substantial Hazard, requires six-month reporting of Post-temporary Solution Status Reports and Remedial Monitoring Reports (310 CMR 40.0898). 

For those sites assigned Temporary Solution status and for which no Active O&M is performed, the proposed MCP amendments would require that status reports be submitted annually (310 CMR 40.0898(1)(b)). However, MassDEP recognizes that in some circumstances the content of annual status reports may not be worth the administrative costs of report preparation. In response and based on “considerations including but not limited to the stability of disposal site conditions and current and foreseeable disposal site risk,” proposed MCP amendments would allow Potentially Responsible Parties (PRPs) to propose lesser reporting frequencies up to the five-year term required for Periodic Reviews (310 CMR 40.0898(1)(c)). Proposals would be subject to a 21-day presumptive approval period. During a March 26, 2020, Advisory Committee meeting, MassDEP stated that it would use its discretion to require reporting at a frequency greater than once in five years if appropriate, e.g., if the PRP needs to be “re-engaged.” If approved, the reduced frequency will apply to reporting only; monitoring frequency and reporting content will remain as is necessary to meet Post-temporary Solution objectives. 

With regard to the requirements of Tier Classification for Temporary Solution sites, the proposed MCP amendments allow that as long as a valid Tier Classification or Extension thereof was in effect at the time the Temporary Solution Statement was filed, the submittal of Post-temporary Solution Status Reports in compliance with 310 CMR 40.0898 will effectively maintain Tier Classification (310 CMR 40.0560(7)(d)(3), 40.0898(1)(e), and 40.1050(4)(c)).

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Review of FY2018 NOAFs for LNAPL

By Wesley Stimpson, LSP, Loss Prevention Committee and LSPA Past President

Each year the LSPA’s Loss Prevention Committee searches the eDEP files, downloads and visually scans Notices of Audit Findings (NOAFs) and Administrative Consent Orders (ACOs) and organizes them in broad categories.  This article provides selected information believed to be helpful to the professional practice derived from the Light Nonaqueous Phase Liquid (LNAPL) category for MassDEP’s fiscal year 2018 (July 2017-June 2018).

Sixteen documents were reviewed in this category in which LNAPL was present and a major contaminant at the disposal sites.  Fifteen of the documents were NOAFs and one was an ACOP (Administrative Consent Order with Penalty) associated with one of the NOAFs.  Five of the NOAFs indicated that the work reviewed did not require additional response actions; these were primarily field audits for remedial systems inspections (RSI), review of remedy operations status (ROS), and site conditions related to Activity and Use Limitations (AUL). 

NOAFs of Note

CEP Not Addressed

Two of the audits resulted in the Department invalidating the submittal.  Both cases involved the filing of a completion report without undertaking the required evaluation and control of a possible Critical Exposure Pathway (CEP). 

The first case was an audit of a 2017 IRA Completion (IRAC) report where 0.06 feet of LNAPL was documented to be present in a groundwater monitoring well approximately 10-20 feet from a multi-family residential building; the depth to groundwater was approximately 7 feet below the ground surface (bgs).  Appropriate notification was made and an IRA undertaken.  The LSP removed LNAPL from the well, demonstrated that it did not return and decommissioned the well.  Ultimately a volume of soil around the well 14 ft by 15 ft by 6 ft deep was excavated.  The soils from the bottom and sidewalls were screened with a PID and a maximum total VOC concentration of 85.9 ppm was measured. 

The IRAC report concluded that the IRA had sufficiently assessed the initial reporting condition.  The Department did not agree and considered the elevated headspace reading to be an indication of “a potential discharge of vapors into a Residential Dwelling” per 310 CMR 40.0313(4)(f)3.  It determined that an additional evaluation of a possible CEP needed to be undertaken before a valid IRAC report could be filed.

In the second case, a 2017 IRA Completion Statement was audited for an IRA reported in 2011 at a gasoline station site.  Over the years of investigation, LNAPL was confirmed to be present and C5 to C8 aliphatics were documented as being present in groundwater and in below-slab and indoor air samples collected in and near occupied dwellings adjacent to the site.  Various LNAPL and vapor recovery actions had been undertaken over the years, including Soil Vapor Extraction, Multi-phase Fluid Extraction, and Enhanced Fluid Recovery.  In addition, a significant amount of LNAPL identification, groundwater quality, and sub-slab and indoor air quality data was obtained. For the completion report, an assessment of risks in the residential structures was undertaken and it was concluded that Imminent Hazard conditions did not exist.

The NOAF pointed out that since the concentration of C5-C8 aliphatics in the sub-slab soil gas exceeded the Residential Sub-Slab Soil Gas Screening Values, and the concentration of C5-C8 aliphatics in the indoor air exceed the Residential Threshold Values, it should have been concluded that Critical Exposure Pathways (CEPs) exist at both residences.

As specified by 310 CMR 40.0414(3) and (4), an IRA is presumed to require the elimination, prevention, and/or mitigation of a CEP, and pursuant to 310 CMR 40.0427(1)(c) an IRA cannot be considered complete until time-critical measures addressing the elimination, prevention, or mitigation of CEPs have been documented with an LSP Opinion concluding that the CEPs have been eliminated or that further response actions will address the CEP.  The LSP did not address the presence of a CEP in the submittal and therefore did not meet this requirement.

NOAFs Involving 2014 MCP NAPL Changes and 2016 LNAPL Guidance

Two NOAFs provided some insight as to how the Department is looking at the implementation of the 2016 LNAPL Guidance. Both involved the level of effort applied to evaluating the feasibility of recovering LNAPL with micro-scale mobility.

In the case of the first submittals, the parties involved with the site could not come to agreement on the execution and recording of an Activity and Use Limitation (AUL), and therefore the submitted document was filed as a Temporary Solution, but set up to support a Permanent Solution once the AUL issues could be resolved.

The audit took exception to the Temporary Solution Statement because it did not include a plan of definitive and enterprising steps to be taken toward achieving a Permanent Solution. Specifically, the Temporary Solution Statement did not include a plan to resolve ownership issues and signatory authority for filing of the Notice of Activity and Use Limitation (AUL). 

In addition, the Department pointed out that while not required for the Temporary Solution, it did not consider that the information provided in the document adequately demonstrated that NAPL with Micro-Scale Mobility had been removed to the extent feasible necessary to support the filing of a Permanent Solution, should the AUL issue be resolved. 

The feasibility evaluation contained in the Temporary Solution indicated that a pump and treat system had operated at the site for 18 years, followed by the installation of skimmers and absorbent booms into specific recovery wells when the LNAPL thicknesses were too small for the skimmers to operate. It did not reference the LNAPL recovery curve analysis provided in a previous RAM Status report and graphically summarized as an attachment in the Temporary Solution Statement.  This graphic demonstrated the declining effectiveness of the recovery operations.

The TSS stated that the LNAPL was not acting as a source of ongoing contamination to the surrounding environmental media, and was stable.  It pointed out that the site is a very busy office complex and additional excavation and/or installation of an additional remedial system would be extremely disruptive to the existing owner. Further, the additional remedial measures would not be able to reduce the residual petroleum constituents remaining in the portion of the site of concern. The submittal stated, based on this completed feasibility evaluation, that additional response actions were not required to obtain a Permanent Solution with Conditions.

The Department recommended that relevant Department guidance be consulted for assessing NAPL removal feasibility to determine what demonstrations will be needed to support the filing of a Permanent Solution.

The second Department opinion on the content of a feasibility evaluation necessary when NAPL with micro-scale mobility is present was provided in the findings of an audit of a Permanent Solution with Conditions.  The feasibility evaluation in the document stated that while technically LNAPL at the site could be physically recovered, either by hand-bailing or using a vacuum truck, it was not economically feasible as there was no additional benefit to be gained by recovering the LNAPL since it is located ~18-20 feet below the ground surface within a public right-of-way, and there is no threat of migration to private/public water supplies or threat to indoor air. Based on the fact that the LNAPL did not exhibit macro-scale mobility and the LNAPL plume was shrinking, the TSS concluded that the cost of additional recovery/remedial measures would far outweigh the benefit of any additional recovery that could be accomplished. Therefore, it was concluded that LNAPL with microscale mobility had been recovered to the extent feasible, and no specific recovery scenarios were evaluated.

The Department’s audit pointed out that for a Permanent Solution, response actions must ensure that for the foreseeable future, all NAPL with Micro-scale Mobility is removed if, and to the extent, feasible  based upon consideration of Conceptual Site Model (CSM) principles and the evaluation needed to comply with 310 CMR 40.0860. MassDEP pointed out that the LNAPL Guidance says CSM documentation at NAPL sites must be based on the principles of fluid flow in porous media (FFPM), describing the presence, distribution, behavior, and stability of the NAPL present. It went on to point out that such FFPM-based Lines of Evidence are primarily quantitative in nature and include metrics such as NAPL transmissivity, estimates of recoverable NAPL using Recovery Decline Curve Analysis, and the site-specific calculation of residual NAPL saturation.

Because the metrics provided in the document audited were limited and semi-quantitative in nature, MassDEP judged that the infeasibility of LNAPL recovery at this site had not been conclusively demonstrated.  The NOAF went on to say that whether the costs of NAPL recovery are worth the benefits of recovering it, 310 CMR 40.0860(5)(b) & (7) state that the factors to be considered include determinations of the incremental cost of NAPL recovery, long-term operation and maintenance costs, and the incremental benefits of environmental restoration and monetary and non-pecuniary values. As described above, the evaluation of costs and benefits provided were qualitative in nature and therefore did not fully meet the requirements of the MCP.  A 90-day period was established for the PRP to revise and resubmit the document.

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Lessons Learned from MNA- and ROS-related NOAF Reviews for 2017 and 2018

By John H. Guswa, JG Environmental, and Michelle N. O’Brien, Esq., Pierce Atwood, both of the Loss Prevention Committee

The LSPA Loss Prevention Committee reviewed 40 Notices of Audit Findings (NOAFs) related to Remedy Operation Status (ROS) and Monitored Natural Attenuation (MNA) for fiscal years 2017 (13 NOAFs) and 2018 (27 NOAFs).  All the NOAFs were issued either by the MassDEP Western Regional Office or Central Regional Office.  The majority of audits did not find a violation, and ROS (often with periodic sampling for MNA parameters) was allowed to continue at these sites. However, Notices of Non-Compliance (NONs) were issued for 14 of the 40 NOAFs (35%), seven in each fiscal year. While there were unique aspects to each of the NONs, there were two common deficiencies in several of the NOAFs - one related to the adequacy of site characterization, and the other to proper reporting.

Adequacy of Site Characterization
In several of the NOAFs reviewed, MassDEP cited parties for inadequate monitoring and reporting of site conditions, and failing to select and implement a remedy that was adequate to achieve a Permanent Solution.  Some of the NOAFs actually noted that monitoring and other data provided in Phase V status and monitoring reports provided documentation that the selected remedy was ineffective and incapable of achieving a Permanent Solution. In a few cases, site data revealed that contaminant concentrations had actually increased, or that a plume had expanded. In all those cases, MassDEP required that ROS be terminated and that Phase II, Phase III, and Phase IV Addenda be submitted in accordance with a specified timetable. Although these deficiencies were site-specific, the NOAFs highlighted the common factor of inadequate site characterization at various phases in the assessment and remediation process.

Proper Reporting
MassDEP also cited parties for failure to submit required status reports or completion statements. Although such “paper violations” sometimes appear minor, this was a deficiency noted in several NOAFs, and failing to comply with reporting requirements can lead to costly consequences. To maintain compliance with the MCP ROS requirements, Phase V Status and Remedial Monitoring reports must be submitted on a semi-annual basis (310 CMR 40.0893(2)(g)). Failure to comply with those monitoring requirements can (and did) result in termination of ROS (310 CMR 40.0893(6)(a)(1)) at several sites. Where ROS has been terminated, either intentionally or by inadvertent failure to comply with reporting requirements, the Potentially Responsible Party has two years from the date of termination to achieve a Permanent or Temporary Solution. Response actions after the ROS termination cannot be conducted without a valid Tier Classification or Tier Classification Extension (310 CMR 40.0893(6)(e)).

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Findings From Review of Fiscal Year 2018 NOAFs Related to Risk Characterization 

 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 Notices of Audit Findings (NOAFs) issued by the Massachusetts Department of Environmental Protection (MassDEP) with a summary of NOAFs that involve risk characterization. The LPC reviewed a total of 7 NOAFs in this category in fiscal year (FY) 2018, which is fewer than the totals in past years.  In the three fiscal years prior to 2018, there were 22 NOAFs (2015), 9 NOAFs and one Administrative Consent Order (ACO) (2016), and 14 NOAFs and one ACO (2017). For FY2018, all 7 NOAFs received NONs.

Like previous years’ reviews of risk assessment-related NOAFs, this year’s review identified three primary areas where deficiencies were noted by MassDEP:

1.  Site Information Required for Risk Characterization (310 CMR 40.0904(2)(a))

Three NONs were issued due to failure to define the extent of the release or adequately characterize the Disposal Site. 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 consideration of each of the media and migration pathways that are relevant to the Disposal Site.

2.  Identification of Exposure Point Concentrations and Other Data Criteria (310 CMR 40.0926)

There were two NONs with violations of 310 CMR 40.0926. In developing an Exposure Point Concentration (EPC), the objective is 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. Therefore, a comprehensive and careful analysis of the data is required to develop appropriate EPCs. In addition, the method used for calculating EPCs should also be clearly stated in the risk characterization.

3.  Performance Standards for Permanent and Temporary Solutions (310 CMR 40.1004(1)(a)&(c))

Although not a violation of the provisions of Subpart I: Risk Characterization, the most common MCP violation related to risk characterization was insufficient assessment and evaluation to support a conclusion of No Significant Risk. Four NONs were issued due to assessments that were not “of sufficient scope, detail, and level of effort to characterize the risk of harm to health, safety, public welfare and the environment posed by the site or disposal site pursuant to 310 CMR 40.0900,” and/or were not “commensurate with the nature and extent of the release or threat of release and complexity of site conditions.”

In addition to the above categories, a violation was identified in a single case for each of the following:

  • Receptor Information Required for Risk Characterization (310 CMR 40.0920),
  • Identification of Exposure Points for Soil Horizontal and Vertical Distribution (310 CMR 40.0924(2)(a)2),
  • Identification of Exposure Pathways (310 CMR 40.0925(1)),
  • Method 3 Environmental Risk Characterization (310 CMR 40.0995), and
  • General Provisions for Permanent and Temporary Solutions Migration Control (310 CMR 40.1003(6)(b)). 

Highlights of risk assessment-related violations identified in the NOAFs are summarized below.  Please note that this article describes issues as they were identified by MassDEP; the LPC author has not independently reviewed the underlying documents cited in the NOAFs.

  • In this first case, a Permanent Solution Statement (PSS) for a release of volatile petroleum hydrocarbons (VPH) to soil concluded that the vapor intrusion pathway was not complete based on groundwater concentrations less than GW-2 and soil gas concentrations less than the sub-slab soil vapor screening criteria; however, concentrations detected in indoor air were above the indoor air threshold values and the concentrations of naphthalene increased in soil gas and indoor air from one sampling round to the next.  In the NON, MassDEP concluded that sufficient documentation was not provided in the PSS to explain the increase in naphthalene and, in such cases where the lines of evidence for the existence of a potential vapor intrusion pathway are ambiguous, further investigation and/or response actions, such as additional data collection, should be performed to reduce uncertainty.

The NON also identified non-compliance relative to how the EPCs for the Disposal Site were calculated.  EPCs were based on the average concentration in soil samples collected from depths of 0-3, 0-6, and 0-15 feet below ground surface (ft bgs). However, MassDEP noted that the surficial soil samples (0-3 ft bgs) contained minimal VPH concentrations and that the vertical distribution of the Disposal Site appeared to range from 3 to 8 ft bgs. As such, the average concentrations in the 0-6 and 0-15 ft bgs intervals (which included the surficial soil samples) resulted in diluted EPCs for soil.  Soil EPCs are required to be calculated as a conservative estimate of the average concentration of site contaminants. Therefore, MassDEP asserted that the soil data as evaluated did not meet the requirements for averaging, per 310 CMR 40.0926(3)(b), and that either a maximum concentration or 95% upper confidence limit of the mean should have been used as the EPC.

  • At another Disposal Site, an NON was issued for a revised PSS with No Conditions due to inadequacies in how soil analyses were conducted, how the soil data were used to calculate EPCs, and the preparation of the PSS.  Soil samples collected from an excavation were variously analyzed for extractable petroleum hydrocarbons (EPH), VPH, or total petroleum hydrocarbons (TPH) with no discernible rationale, according to MassDEP. One sample at the bottom of the excavation that was analyzed for EPH had concentrations above applicable Method 1 Soil Standards and another sample that was apparently deeper than that was analyzed for VPH and also had concentrations above applicable Method 1 Soil Standards.  In addition, although samples were screened with a photoionization detector (PID), samples with the highest readings on the PID were not analyzed.  Because these soil samples were not analyzed, this material was not incorporated into the calculation of EPCs for the Disposal Site.  In addition, TPH results were not included in the EPC calculations although they would be considered representative of soil remaining at the Disposal Site, according to the NON.  Overall, MassDEP concluded that the sampling and analysis as conducted did not adequately delineate the extent of the release and that the approach used to calculate EPCs was not appropriate.  MassDEP also cited additional violations for the PSS because soil sampling depths were not shown on the data table, sidewall sampling locations in the excavation were described but not clearly identified on figures, and north arrows were not provided on figures.
  • One NON was issued for a PSS based on how a potential vapor intrusion pathway at the Disposal Site was addressed.  The subject release at the Disposal Site was petroleum-related; however, analysis of a sub-slab soil gas sample for air-phase petroleum hydrocarbons (APH) reported a detection of tetrachloroethylene (PCE) as a Tentatively Identified Compound (TIC) above the residential sub-slab screening value. The source of the PCE was attributed to a former commercial tenant, and no further evaluation of the vapor intrusion exposure pathway for PCE and related compounds was conducted. MassDEP required the PRP to either revise the risk characterization to include an evaluation of the vapor intrusion pathway or retract the PSS.
  • At a Disposal Site with a release of trichloroethylene (TCE), a NON was issued for a PSS for issues related to how air monitoring was conducted, for what MassDEP considered an inadequate demonstration of the effectiveness of a sub-slab depressurization system (SSDS) at the Disposal Site, and for several deficiencies in the characterization of the extent of the release and potential preferential pathways.  Air samples that were collected in one of the two buildings at the Disposal Site after the installation of an SSDS in that building were collected with a four-hour duration versus the standard eight-hour sampling duration (for commercial receptors), and therefore may have underestimated the indoor air concentrations in the building. In addition, the sub-slab soil gas field screening data and the soil gas samples collected from points beneath the building with the SSDS were deemed to be of insufficient scope to confirm the incompleteness of a potential vapor intrusion pathway, and thus did not demonstrate the effectiveness of the SSDS. Furthermore, based on substantive alterations to the other building and proposed plans to occupy it, MassDEP required additional assessment of indoor air in the other building.

In addition, MassDEP concluded that the scope of the vapor intrusion assessment, which modeled the vapor intrusion pathway for a potential future resident prior to the building conversion to residential use (which occurred after the submittal of the PSS), was inadequate based upon the site complexities and the human health hazards associated with TCE.  MassDEP noted that the use of a default attenuation factor did not account for changes to the building that may occur during renovation, including the creation of new preferential pathways (changes to building construction, installation of new utilities, HVAC adjustments, etc.). MassDEP cited this as a failure to determine a conservative estimate of EPCs for contaminants in indoor air, a violation of 310 CMR 40.0926(3).

Based upon the absence of indoor air data to confirm a condition of No Significant Risk at the time the original PSS was submitted and the proposed renovation plans for the Disposal Site, MassDEP disapproved of a PSS with No Conditions as an appropriate choice. In the NON, MassDEP stated that a more suitable approach would have been to submit either a Temporary Solution Statement or a PSS with Conditions, including a Notice of Activity and Use Limitation requiring the collection of indoor air data subsequent to the building conversion to residential use to confirm that site conditions posed No Significant Risk to future residents.

Summary.  Because the MCP allows remediation decisions to be based on the risk posed by site conditions, as opposed to requiring cleanup to background or numerical standards, it is important that LSPs provide risk characterizations which are sufficient to support site cleanup decisions and which adequately support the conclusion that site conditions are protective of human health, safety, public welfare, and the environment.  While the number of risk characterization-related NOAFs was lower in FY2018 than in prior years, this year’s review demonstrates that MassDEP continues to issue NONs due to a lack of sufficient scope, detail, and level of effort in conducting site assessments to support PSSs and risk characterizations; inadequate delineation of the nature and extent of Disposal Sites; and approaches to calculating EPCs that are inconsistent with the MCP.