Loading...
31B-269 47 Ctr St MassDEP-1 File Review Memorandum To: Site file, RTN 1-13601, Masonic Lodge, 47 Center Street, Northampton Through: John Ziegler, Section Chief, BWSC-ASM From: Rebecca Woolley, BWSC-ASM Date: January 3, 2012 Re: Comprehensive Audit Site Description and History The site is a 6,600 square foot property located in a commercial/residential area of downtown Northampton. The property was developed in 1906 with a two-story brick building with a basement by New England Telephone and Telegraph, and operated as a telephone office until 1956. From 1963 to approximately 2004, the site was used as a Masonic Temple. The site building is currently vacant, although it is zoned for commercial use. A multi-use property is located across Center Court to the east. This building contains residential units on upper floors, commercial businesses on the ground floor, and a seasonal homeless shelter in the basement. Center Court and private residences abut the site to the north, a commercial building abuts the site to the west. The site is located approximately 0.5 miles east of the Mill River. The property is serviced by municipal water and sewer. Currently, an AST located in the basement contains #2 heating oil, which is used to supply heat to the building. Groundwater at the disposal site is categorized as GW-2 (where applicable) and GW-3. Site soils consist of fine sand and silt with horizontally laminated silt and clay to approximately 17 feet below grade (fbg). These deposits are associated with Glacial Lake Hitchcock and tend to be comprised of silt and clay interbedded with discontinuous layers of sand, and may extend to depths greater than 70 fbg. The depth to water at the site ranges from 3 to 20 fbg, and the groundwater flow direction is generally to the east/southeast towards the Connecticut River. The average depth to water is 15 fbg. However, this highly variable water table is characteristic of a perched water table overlying Glacial Lake Hitchcock deposits. Response Action Summary On August 28, 2000, a 1,000-gallon UST containing #2 fuel oil was removed. The UST was located adjacent to the northeastern side of the building. Evidence of a release was observed in the excavation and a PID reading in excess of 100 ppmv triggered the reportable notification to the Department as an IRA. On September 28, 2000, the former UST area was over-excavated and approximately 44 tons of impacted soils were excavated and properly disposed. As part of the IRA, four monitoring wells were installed. On December 28, 2000, approximately 0.5 feet of LNAPL was observed on groundwater in monitoring well MW-1, and the Department was notified of the LNAPL. An IRA Plan Modification was received in January 2011 to address the LNAPL. The Phase I Report with a Tier II Classification was completed in August 2011. IRA Status reports were received in March and September 2002, and April 2003. File Review Memorandum RTN 1-13601, Masonic Lodge, 47 Center Street, Northampton Page 2 of 3 During assessment activities, LNAPL was also detected at thicknesses greater than 0.5 inch in monitoring wells MW-4, MW-6, MW-7, MW-10, and EW-1. Throughout the project lifecycle, approximately 25 gallons of fuel oil were recovered by manual bailing and disposed. On August 19, 2004, the Department issued NON-WE-04-3089 to the Jerusalem Lodge Association for failure to submit Phase II and III reports, and failure to submit the IRA Status Reports due on October 11, 2003 and April 11, 2004. In July 2004, ownership of the site transferred from the Jerusalem Lodge Building Association to 47 Center Street, LLC. On June 3, 2005, the Department issued an NOR and Interim Deadlines to the new property owner 47 Center Street, LLC, requiring a Tier II classification transfer by June 30, 2005, an IRA Status or Completion Report by June 30, 2005, and a Phase II/III Report by September 30, 2005. Submittal of these reports was completed, but not by the exact deadlines. The Phase II report concluded that comprehensive response actions were necessary and the Phase III proposed multi- phase extraction HIT events, followed by MNA. In February 2006, the Department received an IRA Plan Modification, which proposed surfactant injections coupled with the HIT events. Between 2006 and 2007, the Department issued two additional NONs to 47 Center Street, LLC for failure to meet submittal deadlines, and established additional Interim Deadlines. In July 2007, the Department received a Phase IV-RIP, which proposed ISCO injections to address persistent LNAPL. On October 24, 2007, approximately 15,400 pounds of sodium persulfate were injected into the saturated zone at the site. Following the ISCO injection event in October 2007, combined IRA/Phase IV Status Reports were received in January and May 2008, and March 2009. No additional status reports were received until March 2011, when higher level enforcement activities were initiated. The Department and 47 Center Street, LLC entered into ACOP-WE-11-3003 on July 1, 2011. The ACOP required that indoor air sampling be conducted at 47 Center Street and at any other potentially impacted, occupied buildings. The requirements of the ACOP were complied with by the submittal of a Class A-2 RAO Statement received by the Department on July 29, 2011. The vapor intrusion pathway was addressed by soil gas and indoor air samples collected at the site in March 2011. One soil gas sample, identified as SG-1, was collected from beneath the basement concrete slab of the site building, and one indoor air sample was collected from within the basement. Both samples were analyzed for APH. The results from the soil gas sample were compared to Method 2 soil gas screening levels and passed. The indoor air sample results were compared to the 75th and 90th percentile concentrations of the Department published typical indoor air concentrations. All analytes were below the 90th percentile, with only concentrations of C5 – C8 aliphatic hydrocarbons exceeding the 75th percentile. The comprehensive audit of the RAO identified two areas of concern, which are addressed below. With regard to the above referenced RAO Statement, the Department had two areas of concern. The first area being that the average calculated LNAPL thickness presented was 0.59 inches, which is greater than the UCL of 0.5 inches. While the average calculated LNAPL thickness was greater than 0.5 inch, approximately half of the wells used to calculate the average were one-inch diameter wells, which tend to overestimate the LNAPL thickness. The boring logs for the data points containing LNAPL do not show that continuous layers of LNAPL exist in the formation. The subsurface geology at the site consists of Glacial Lake Hitchcock deposits with discontinuous sand stringers trapped in layers of varved clay. Even the groundwater table at File Review Memorandum RTN 1-13601, Masonic Lodge, 47 Center Street, Northampton Page 3 of 3 the site is highly variable and likely perched. Monitoring data collected from 2000 through 2011 have proven that the LNAPL is not mobile and the groundwater analytical data at the site supports that the LNAPL is not significantly partitioning into groundwater. Furthermore, sub- slab soil gas and indoor air analytical data indicate that vapor intrusion into indoor air is not a risk to the site building. Therefore, the Department concludes that multiple lines of evidence support that the thickness of LNAPL remaining in monitoring wells at the site does not constitute a UCL exceedance. The second area of concern was that following the injection of 15,400 pounds of sodium persulfate into the saturated zone in October 2007, remedial additive monitoring of groundwater was not conducted within required quarterly intervals. The Department expects post-remedial monitoring requirements be followed during and after the application of remedial additives to evaluate the potential for migration of OHM to nearby subsurface utilities and occupied structures. However, as this audit was conducted following the submittal of an RAO, the opportunity to correct this violation in progress has passed. In this case, the post-remedial monitoring conducted, while deficient with the schedule outlined in the regulations, was sufficient to demonstrate that LNAPL migration to sensitive receptors did not occur. Site Inspection A site inspection was conducted by Rebecca Woolley of the Department on December 21, 2011. Marc Richards (LSP-of-Record), of Tighe & Bond attended the audit inspection on behalf of Eric Suher (Manager) of 47 Center Street, LLC. The site walk-over only included the exterior areas of the disposal site, during which many of the site monitoring wells were observed to be unsecured or inadequately maintained. Several monitoring well roadboxes were missing bolts, gripper caps, and the pavement surrounding the wells was either missing or damaged. The Department advised that the monitoring wells be adequately maintained or properly decommissioned. During the audit inspection, preliminary audit findings were discussed. One focus area of the discussion included the remedial additive monitoring schedule and the requirements of monitoring for OHM both during and immediately following remedial additive application. In this case, monitoring for LNAPL, changes in groundwater elevation, and monitored natural attenuation field parameters was performed within the first three months following the remedial additive application. Therefore, it was determined that no violation occurred.