Highlights from FY '13 Notice of Audit Findings - Nature and Extent 
By: James Zigmont, LSP, CDM Smith, and Loss Prevention Committee

As part of the Loss Prevention Committee's (LPC) topic-based continuing series of reviews of 2013 Notices of Audit Findings (NOAFs), this article presents highlights from NOAFs that address issues involving the nature and extent of contamination. The observations below are intended as practice tips for the LSP community. Given that the LPC will present a subsequent article devoted to vapor intrusion-related NOAFs, this article does not describe vapor intrusion issues, although these are a leading component of identified noncompliance within nature and extent-related NOAFs. 

GENERAL ISSUES OF SITE CHARACTERIZATION

Provided below are some examples of the nature and extent issues cited by MassDEP in NOAFs, such as sampling parameters, assessment of historical usage, and lateral and vertical contaminant delineation.

• Dioxins were not assessed in the tailrace of a former paper mill that drained a settling basin where dioxins had been detected;
• An industrial use building interior was not assessed for potential sources of oil or hazardous material (OHM), such as drains, drywells, and the potential use and storage of OHM;
• Cyanide was excluded from a site's sampling and analysis program although cyanide had been identified as part of the historical waste stream;
• A paint shop floor drain identified in an industrial building was not investigated as a potential source of contamination;
• The extent of impacts relating to metals, principally lead, detected in soil at a municipal park were not characterized;
• The extent of filling was not delineated within a portion of a property reportedly developed over a landfill;
• Impacts to an intermittent stream were not adequately characterized where metals in groundwater at the adjoining property were detected in excess of GW-3 criteria;
• Oil-stained soil located outside of an area of soil excavation performed as a Release Abatement Measure was not characterized during response actions or addressed in the Response Action Outcome statement; and
• An LNAPL-impacted well was destroyed and not replaced, nor were other wells installed farther downgradient from the well in question.

GROUNDWATER CLASSIFICATION

MassDEP identified several instances of noncompliance relating to the assignment of groundwater classifications:

• An RAO stated that GW-1 criteria did not apply based on the criteria in 310 CMR 40.0926(8)(c); however, MassDEP disagreed with this opinion based on increasing groundwater contaminant levels within a Zone II area;
• An RAO's groundwater categories did not address private wells located within 500 feet of the site despite their description in an earlier Phase II Report;
• An RAO did not assign a GW-1 category to site groundwater despite the site's partial inclusion within a Zone II area; and
• An RAO concluded that a disposal site's groundwater was not category GW-1 solely on the basis of the decommissioning of a private drinking water well, although the area was also classified as a Medium Yield Potentially Productive Aquifer.

DISPOSAL SITE BOUNDARIES

MassDEP identified lack of or inadequate definition of disposal site boundaries in the following cases:

• An RAO did not present disposal site boundaries despite characterizing groundwater impacts as extending onto adjacent property; and
• MassDEP determined that groundwater flow directions within the overburden and bedrock aquifers were not adequately characterized to support the RAO's disposal site boundary. MassDEP stated that based on the presented data, GW-2 exceedances from PCE impacts in potential downgradient areas could not be ruled out.

CLEAR AND CONSISTENT DESCRIPTION OF SITE AND RESPONSE ACTIONS

In some cases, MassDEP determined that RAOs did not present clear and consistent depictions of site conditions and response actions, and therefore did not provide a convincing rationale for closure. In one example, MassDEP concluded that the RAO did not present:

• a consistent depiction of disposal site boundaries;
• information on NAPL occurrence and related response actions despite earlier references to these;
• construction details of three monitoring wells;
• critical confirmatory soil data (tables and lab sheets) from the area of highest petroleum impacts;
• groundwater flow direction; and
• an explanation of the relevance of identified below-ground utilities in proximity to a removed underground storage tank.

In another example, MassDEP determined that an RAO's disposal site boundaries had been reduced from a larger property that included a GW-1 Medium Yield Potentially Productive Aquifer as shown in the Phase II Report, to a more limited GW-2/GW-3 area defined by the extent of soil removal performed during a RAM. The RAO provided no explanation for the reduced boundaries. 

EVALUATION OF NON-POTABLE SUPPLY WELLS

As part of one NOAF, MassDEP cited four non-potable private wells located within 500 feet of a disposal site for which the RAO did not provide adequate justification to exclude them from within the disposal site boundaries. Although the NOAF allowed that non-consumptive use of the private wells did not by itself require a GW-1 classification, MassDEP stated that non-potable use requires a Method 3 Risk Characterization to evaluate exposures not addressed by the RAO's Method 1. The NOAF went on to state that the RAO did not provide an adequate description of the locations, depths, and construction details of these wells. 

METHANOL PRESERVATION AND HISTORIC SAMPLES

An NOAF for a 2012 combined Phase II/Phase III Report found that characterization of the site source area relied on 1997 VOC soil results with no indication that the samples had been preserved with methanol, as currently required per Policy WSC#99-415. MassDEP concluded that use of data from unpreserved samples inadequately characterized soil impacts and was therefore noncompliant. 

COMPLIANCE WITH TSCA

Notification had been provided to MassDEP of a potential imminent hazard for 2,800 mg/kg PCBs detected in surface soil. The soil was later removed during three separate excavations. MassDEP noted in the NOAF that EPA was not notified and response actions did not comply with TSCA regulations. This noncompliance with TSCA was identified by MassDEP a violation of the MCP. 

SUBSEQUENT PROPERTY TRANSFER DUE DILIGENCE REPORT

In a situation experienced by many LSPs over the past few years, MassDEP issued an NOR as a result of a Level 3 Audit eight years following submittal of a Class A-2 RAO. The audit and subsequent NOR were prompted by a due diligence assessment report submitted by a third party to MassDEP. The report detected soil and groundwater impacts above the Method 1 criteria that had been used to support the RAO. The assessment also detected soil vapor constituents above MassDEP's threshold values for VOCs. MassDEP required retraction of the RAO and Tier Classification within one year.