This column focuses on noteworthy audits conducted by MassDEP's Bureau of Waste Site Cleanup between April and June 2007 as well as providing general audit information. 

April, May and June 2007 Level 1 Audits

MassDEP completed Level 1 (L1) file review audits (using Technical Screening Audit Forms) on 603 response actions at sites between April and June 2007.  Although MassDEP does not issue Notice of Audit Findings at the outcome of L1 Audits, available information is used to prioritize MassDEP's focus for Level 2 and Level 3 Audits. 

April, May and June 2007 Level 2 Audits

MassDEP completed Level 2 (L2) audits and issued Notices of Audit Findings (NOAFs) at 89 sites between April and June 2007.  Twenty-four Notices of Noncompliance (NONs) were issued, together with MassDEP's findings.  L2 audits of interest between April and June 2007 include:

1. MassDEP completed a L2 audit of a site where Monitored Natural Attenuation (MNA) is being conducted as the remedy through Remedy Operation Status (ROS).  MassDEP issued a Notice of Audit Finding (NOAF)/Notice of Noncompliance (NON), which concluded that response actions were not performed in compliance with the requirements of the MCP.  Through its audit, MassDEP noted that the ROS submittal does not meet the Performance Standards for ROS.  Specifically, it did not demonstrate that any Substantial Hazard has been eliminated, or that the proposed MNA has been adequately designed in accordance with 310 CMR 40.0870 to achieve a permanent solution.  MassDEP noted that a Substantial Hazard Evaluation was not provided in the ROS Submittal, and the risk characterization conducted during Phase II did not demonstrate that no current exposure pathways exist.  The Method 1 risk characterization included in the Phase II was based on a general screening approach and concluded that since concentrations of volatile petroleum hydrocarbons (VPH) exceeded GW-3 Standards, a significant risk existed.  The Phase II report states that GW-2 does not apply to the site, as all sample points are more than 30 feet from structures.  While monitoring wells may have been slightly more than 30 feet from nearby residential structures, no further delineation of the GW-2 exceedence was conducted.  Therefore, the potential for indoor air to be affected by the release or the ability to assert a condition of No Substantial Hazard was not adequately addressed by the risk characterization.  MassDEP also noted that in the absence of a full characterization of extent of the release and the potential risk posed by the release, it is not appropriate to conclude that the proposed MNA remedy will be adequate to achieve a permanent solution.  The ROS Opinion concludes that the plume is stable or shrinking based on samples collected from wells located downgradient.  Over two sampling rounds, concentrations of some contaminants increased both downgradient and crossgradient of the release and toward the adjacent residences.  These data do not demonstrate that the plume is stable or shrinking, and may indicate that the plume is expanding.  MassDEP required submittal of a revised ROS, prepared in accordance with 310 CMR 40.0893, including a Substantial Hazard Evaluation prepared in accordance with 310 CMR 40.0956, that addresses the violations identified and complies with the requirements of the MCP; or retraction of the existing ROS Opinion. 

Follow-up:  In response to the audit, additional downgradient assessment of the site was conducted.  The additional assessment indicated that the extent of groundwater contamination included the downgradient residential structures at levels exceeding GW-2.  Soil gas samples collected within 30 feet of the structures indicated a possible Imminent Hazard condition and release notification to MassDEP (RTN 2-0016807).  Total Air Petroleum Hydrocarbons (APH) in soil gas were measured at more than 600,000 ug/m3.  Additional Immediate Response Actions (IRAs) are ongoing.  (Marlborough, RTN 2-0000774, NON-CE-07-3A043, May 3, 2007) 

2. MassDEP completed a L2 audit of a remedial action at a site that currently consists of MNA.  MassDEP issued a NOAF/NON, which concluded that response actions were not performed in compliance with the requirements of the MCP.  Through its audit, MassDEP noted that multi-phase extraction (MPE) was the remedy originally selected for the site and was implemented in 2000 under ROS.  In 2005, ROS was terminated when it was determined that MPE was no longer effective at reducing contamination at the site.  MNA was subsequently selected as the alternative remedial action.  However, MassDEP noted that groundwater data from some of the monitoring wells did not show an obvious downward trend in concentrations.  In addition, MNA had not previously been evaluated in the 1998 Phase III report to determine if it was a feasible remedy to implement.  While "bioremediation" had been discussed briefly in the Phase III, that remedy relied on the introduction of oxygen to the subsurface, which is not part of MNA.  Furthermore, MassDEP noted that the Operation, Maintenance and Monitoring (OMM) Plan was not modified to accommodate the switch to MNA-only activities in 2004.  The collection of dissolved oxygen (DO) and oxidation-reduction potential (ORP) data during well-sampling as the only MNA indicators is inadequate, and at a minimum, additional data should be evaluated to show contaminant destruction is occurring.  Within a specified time period, MassDEP required submittal of a Phase III Addendum in support of the selected remedy and an updated OMM Plan.  (Greenfield, RTN 1-10009, NON-WE-07-3A060, May 24, 2007) 

April, May and June 2007 Level 3 Audits

MassDEP completed Level 3 (L3) audits and issued NOAFs at 30 sites between April and June 2007.  Twenty-one NONs were issued with MassDEP's findings.  L3 audits of interest between April and June 2007 include: 

1. In October 2006, MassDEP received a 72-hour release notification for a release of petroleum hydrocarbons at a former gas station site currently used for used car sales and garage/lot.  The site is located in an area of mixed commercial and residential use.  The on-site building is serviced by municipal water and a septic system, which appeared to be a brick and concrete block cesspool.  Floor drains from the garage bays discharge to the cesspool.  A residence located 300 feet southwest of the site is serviced by a private water supply well.  The identification of the private well proximate to the site prompted notification.  Immediate Response Action (IRA) assessment activities were conducted.  A Class B-1 Response Action Outcome (RAO) Statement with a Method 1 risk characterization was submitted to MassDEP in October 2006.  MassDEP issued an NOAF/NON concluding that the Class B-1 RAO was not in compliance with the MCP, and does not support a conclusion of No Significant Risk (NSR).  The Method 1 risk characterization stated that the groundwater is classified as GW-2 and GW-3 and that the GW-1 category does not apply since the groundwater flow at the site is to the southeast and not to the southwest where the private well is located.  No information was provided in the RAO report regarding the construction specifications of the private water supply well or its pumping rate.  The RAO also stated that no uncontrolled sources of contamination were identified at the site.  MassDEP noted that although justification was presented for not applying the Method 1 GW-1 category, it did not include information on the depth and construction of the private well in conjunction with the a demonstration that there is no hydro geologic connection between the groundwater and the private water supply well, based on an investigation and an evaluation of site-specific conditions in accordance with the MCP at 310 CMR 40.0932(5)(d).  Therefore, this justification was not adequate.  Furthermore, the extent of contamination downgradient of the site and uncontrolled discharges and/or source areas (the cesspool) was not addressed.  MassDEP noted that the floor drain within the garage bay discharges to the cesspool that serves as the sanitary disposal system for the building.  This is not a permitted discharge and, as such, the floor drain should be closed in accordance with the Underground Injection Control (UIC) regulations (310 CMR 27.00).  Within a specified timeframe, MassDEP required submittal of a revised RAO or retraction of the RAO with continued response actions.  (Abington, RTN 4-20119, NON-SE-07-3A-024, May 17, 2007).

2. In September 1993, MassDEP received a 120-day release notification for a release of petroleum hydrocarbons to groundwater at a municipal property.  The source of release was identified as the former underground storage tanks for fuel oil, diesel, and gasoline.  Response actions included comprehensive assessment with a recommendation for remedial actions, which were selected to be limited groundwater extraction and addition of Oxygen Releasing Compounds (ORCs).  Remedial activities began in 2005 and ORC was switched to regenerated oxygen in 2006.  A Class A-2 RAO with a Method 1 and 2 Risk Characterization was submitted to MassDEP in October 2006.   MassDEP issued an NOAF/NON concluding that the Class B-1 RAO was not in compliance with the MCP, and does not support a conclusion of No Significant Risk (NSR).  MassDEP noted that the exposure point concentration (EPC) calculated for lead (531 parts per million or ppm) was compared to the MassDEP's background lead concentration for soil containing coal/wood ash associated with fill material (600 ppm).  As indicated in the technical update, all laboratory analytical data points for OHM must be below the applicable background values for the OHM to be considered present at background concentrations.  Three of the lead concentrations presented in the soil analytical summary table exceeded the lead background value for soil containing coal ash or wood ash associated with fill material; one of the values exceeded the Upper Concentration Limit (UCL).  Only three of the twenty-two soil boring logs (MW-9, B-2 and B96-4MW) indicated the potential presence of ash.  Analytical results from nine soil samples were used to determine EPCs for the volatile petroleum hydrocarbons (VPH); results from fourteen soil samples were used to determine the EPC for lead.  The samples were collected between 4 and 6 feet below grade.  The EPCs were compared to the MassDEP's S-1 soil standards.  For the determination of the lead EPC, only nine of the samples (64%) had lead concentrations equal to or less than the S-1 standard.  The arithmetic average of the lead concentrations (531 ppm) is greater than the MassDEP's S-1 soil standard and one of the data points is more than ten times the MassDEP's S-1, S-2 and S-3 standards.  Insufficient justification was provided concerning the sample mean with regard to data distribution, etc.  Also, the calculated soil EPC for the C5 - C8 aliphatic was 109 ppm, which exceeds the S-1 standard of 100 ppm.  By a specified date, MassDEP required submittal of a revised RAO, including a revised risk characterization, or a Tier II Permit Extension and RAO retraction to continue with response actions.  (Wakefield, RTN 3-10561, NON-NE-07-3A035A, June 4, 2007). 

April, May and June 2007 Helpful Hint

Q: What is the most appropriate way to evaluate risks to public welfare as they pertain to the Upper Concentration Limit (UCL) comparison of the data.  The MCP can be read as recommending a comparison of the EPC to the UCLs or comparing the data on a point-by-point basis to the UCLs.  How does DEP recommend comparing data to the UCLs? 

A: UCLs are compared to the AVERAGE contaminant concentration (excluding hot spots), and NOT to individual data points.  Per 40.0926(3), EPCs are calculated as the average concentration (excluding hot spots) of contaminants contacted by a receptor at the Exposure Point, for comparison to Method 1 or 2 standards and/or use in a Method 3 risk assessment.  When determining compliance with UCLs, identical methods are used to establish this "average" concentration [e.g., the most commonly used technique is listed at 40.0926(3)(b)(2)].  However, this average concentration is not referred to as an "Exposure Point Concentration" because UCLs address future risks to public welfare and the environment, and are independent of "exposure" to biological receptors (human/eco). 

April, May and June 2007 Observations and Notes

• Of the 24 L2 Audit NOAF/NONs issued between April and June 2007, MassDEP cited 70 violations of the MCP.  The most common violation cited was 40.0891(3), failure to follow the Operation, Monitoring and Maintenance (OMM) plan; or modifications of the OMM plan without notice. 
  
  
• Of the 21 L3 Audit NOAF/NONs issued between April and June 2007, MassDEP cited 79 violations of the MCP.  The most common violation cited was 40.0904(2)(a), failure to define the horizontal and vertical extent and concentrations of oil and/or hazardous materials in all evaluated media.
  
   
• A historical compilation of all Audit Helpful Hints as well as past issues of "The Agency Speaks - Audit Update" column, the Audit Fact Sheet and copies of the Level 1 Audit Technical Screening Forms can be found on MassDEP's Audit Program website at: http://www.mass.gov/dep/cleanup/compliance/audits.htm. 

Finally, some additions to the Audit Update column were made in hopes that the regulated community would find them useful.  Please forward any thoughts, comments or suggestions to Thomas.Potter@state.ma.us.