May 2021 Newsletter Article

Lessons Learned from FY'19 Nature & Extent-Related NONs

By Jim Begley, LSP, MT Environmental Restoration and LSPA Loss Prevention Committee member

The LSPA Loss Prevention Committee reviewed Notices of Audit Findings (NOAFs) issued by the Massachusetts Department of Environmental Protection (MassDEP) for fiscal year 2019 related to the MCP requirements for defining the Nature and Extent (N&E) of Oil and Hazardous Materials at Disposal Sites.  All thirteen audit findings reviewed resulted in Notices of Noncompliance (NONs) issued to Responsible Parties.  Permanent Solutions or Response Action Outcomes were invalidated by MassDEP in two cases.  The N&E audits issued included:

  • 3 from the Western Regional Office,
  • 2 from the Central Regional Office,
  • 2 from the Northeast Regional Office, and
  • 6 from the Southeast Regional Office. 

The NOAFs related to ten Permanent Solution Statements/Response Action Outcomes, one Permanent Solution with Conditions, one Temporary Solution, and one Phase IV submittal. 

MassDEP referenced deficiencies in the following areas:

  • Application of Conceptual Site Models (CSM),
  • Definition of disposal site boundaries,
  • Incomplete data sets and scope of investigation, and
  • Insufficient information to support risk evaluations.

These deficiencies included the failure to define the N&E for contaminants of concern (CoCs) and eliminating CoCs from further investigation without sufficient or appropriate cause at two sites, including one where a CoC was incorrectly attributed to historic fill and one where historical data was available but not considered.  At the site where a contaminant was incorrectly attributed to historic fill, the contaminant, 1,4-dioxane, was identified in a groundwater sample collected from a test pit at a petroleum site.  The N&E of the 1,4-dioxane was not investigated further even though MassDEP policy states that VOCs at significant concentrations are likely due to a release/condition that would not meet the definition of historic fill.  At the site where MassDEP identified historical data that was not considered as part of the risk assessment, the problem was that there was insufficient documentation to support an opinion that these data could be omitted.

At five sites, MassDEP identified additional deficiencies that resulted from a failure to collect information over a wider area or in a specific area, including incomplete plume definition both horizontally and vertically.  One of these NOAFs resulted in an NON and cited the lack of investigation in bedrock; in this case excavation at the source area identified TCE in soil down to the bedrock surface and TCE in groundwater in bedrock monitoring wells, but did not include an assessment of the direction of groundwater flow or the extent of the TCE plume. 

NOAFs at two sites related to insufficient investigation of all media, including one site where indoor air samples were not collected when the building was wasn’t being ventilated and one site where soil but not groundwater was investigated.  The assessment and subsequent risk characterization did not consider reasonably foreseeable site activities and uses (and potential future exposures) and a likely change in future conditions. 

Four NOAFs referenced incomplete assessment, specifically of source areas.  Two of these NOAFs identified problems with the methodology used, including investigating groundwater concentrations by sampling a frac tank.  Water samples collected from the frac tank were not likely to be representative of groundwater due to the potential loss of VOCs; in addition, the level of precision and accuracy would not meet Response Action Performance Standards.

The number of 2019 NOAFs and NONs issued by MassDEP for issues relating to the assessment of N&E indicates that this topic remains a significant focus for MassDEP.  The N&E-related NOAFs from FY 2019 indicate improvements in compliance and outcomes could be achieved by additional focus on:

  • Developing and consistently referencing a well-thought-out CSM, revising it as necessary through appropriate investigation and updates,
  • Better delineation of disposal site boundaries,
  • Attention to MCP requirements and guidance, and
  • Thorough documentation of the basis for LSP decisions regarding the assessment of N&E in submittals.