Kaufman Astoria Studios Hellenic Service Station
Posted on June 12, 2015
Client: Hellenic Service Station
Location: Astoria, New York
Project Type: Underground Storage Tank Investigation and Remediation
Project Period: April 2009 - March 2010
Project Cost: $283,000
D&B Engineers and Architects, P.C. was retained by Corner Piece Astoria, LLC to provide oversight activities associated with the removal and closure of 14 underground storage tanks (USTs) at a former gasoline and vehicle repair service station property located in Astoria, New York. All closure activities were completed under an expedited schedule, in order to meet the client’s real estate transaction deadline. In order to achieve this aggressive schedule, D&B worked closely with the New York State Department of Environmental Conservation (NYSDEC) field inspector and required the excavating contractor to utilize additional heavy equipment to expedite the excavation of the USTs. In addition, D&B received all post-excavation confirmatory soil sample results on an expedited 2-day “turnaround” basis.
The Hellenic Service Station site was an active gasoline and vehicle repair service station that operated from approximately 1960 to 1999. As described above, the site contained 14 USTs, including 12 gasoline USTs, one heating oil UST, and one waste oil UST. In addition, two hydraulic vehicle service lifts were also located at the site. When gasoline and vehicle repair operations ceased in 1999, the 12 gasoline USTs and the waste oil UST were abandoned in-place via concrete slurry injection. The heating oil UST and two hydraulic vehicle service lifts were not abandoned and remained in service.
Phase I and Phase II ESA
Prior to undertaking the site remediation, D&B completed a Phase I Environmental Site Assessment (ESA) of the site in July 2009. The Phase I ESA indentified two NYSDEC open spills associated with the site. However, one open spill was later determined by the NYSDEC to be a duplicate of the initial open spill, and was subsequently closed by the Department. The Phase I ESA also identified that a NYSDEC spill report issued in 1995 documented contamination in the gasoline UST fill ports, oil spills around the waste oil tank and overall poor housekeeping at the site. In addition, the Phase I ESA also revealed that a subsurface investigation was completed at the site in 2004, which identified relatively high concentrations of methyl tert-butyl ether (MTBE) in site soil and groundwater, and elevated concentrations of xylene in site groundwater.
Based on these findings, D&B completed a Phase II ESA in August 2009. In general, evidence of significant petroleum contamination was not observed in site soil. However, black staining and a strong hydrocarbon odor was observed in soil samples collected immediately to the south of the 12 gasoline USTs. In addition, the Phase II ESA identified several polycyclic aromatic hydrocarbons (PAHs), including benzo(a)anthracene, benzo(b)pyrene, chrysene and phenol, and several metals, including arsenic, barium, beryllium, cadmium, chromium, copper, iron, lead, mercury, nickel, vanadium and zinc, in site soil. However, these compounds were generally detected only marginally above their respective NYSDEC soil cleanup objectives (SCOs) and were attributed to the historical fill underlying the site and the historical industrial nature of the site and surrounding areas.
In addition, D&B’s Phase II ESA identified on-site groundwater contamination, primarily gasoline-related compounds including, benzene, toluene, ethylbenzene, and xylene (BTEX) and MTBE. However, the MTBE concentrations detected during D&B’s Phase II ESA were considerably lower than the MTBE concentrations detected during the 2004 subsurface investigation. This may be attributed to natural degradation, MTBE’s highly mobile nature in groundwater and the fact that gasoline service operations had ceased in 1999. Based on these findings, D&B recommended the removal of all on-site USTs and any associated soil contamination in order to achieve spill closure prior to the purchase of the property by the client. In addition, the two hydraulic vehicle service lifts located at the site were also recommended to be removed as part of the UST removal and closure activities.
UST Removal and Soil Remediation
D&B provided all oversight and soil screening activities associated with the excavation and removal of the 14 USTs and hydraulic vehicle service lifts. All field activities were conducted in October and November 2009. The excavations were accomplished utilizing hydraulic hammers to break through surface paving and the concrete UST encasements, which were up to 3-feet thick in some areas. Excavators were utilized to remove the tank carcasses and associated contaminated soil. Note that, the limited/confined area of the site presented several equipment and soil management challenges, which were quickly and efficiently resolved via close coordination between D&B, the excavating subcontractor and the NYSDEC.
Following removal, the USTs were cut open and the tank contents, including any accumulated liquids, were removed and properly disposed off-site. The UST carcasses were then cut into manageable pieces, and the UST carcasses and hydraulic vehicle lifts transported off-site for recycling.
Given one of the primary goal of the assignment was to obtain closure of the NYSDEC open spill prior to purchase of the property by the client, the former UST areas were over-excavated in order to ensure all petroleum contaminated soil was removed from the site prior to the collection of endpoint soil samples. A total of 547 tons of soil was excavated from the site and transported off-site for proper disposal.
Soil Screening and Endpoint Soil Sampling
Soil screening was performed throughout the UST excavations utilizing a photionization detector (PID), and a total of 36 endpoint soil samples were collected from the open excavations for laboratory analysis for NYSDEC Spills Technology and Remediation (STARS) volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). Of the 36 collected endpoint soil samples, one side wall soil sample collected from the waste oil UST excavation exhibited one VOC (MTBE) in exceedance of its NYSDEC SCO. In addition, several SVOCs were detected in exceedance of their respective NYSDEC SCOs in several endpoint soil samples, but as described above, this was attributed to the historical fill underlying the site and the historical industrial nature of the site and surrounding areas. Following review of the endpoint analytical data, the excavations were backfilled to grade with clean certified fill.
Reporting and Spill Closure
Immediately following completion of all UST closure activities, D&B submitted a UST Closure Report to the NYSDEC in late December 2009 for review and approval on an expedited basis. The UST Closure Report summarized all completed field activities and endpoint soil sample results, and provided recommendations for spill closure. The UST Closure Report was quickly approved by the NYSDEC and the NYSDEC open spill associated with the site was closed in early February 2010, prior to the aggressive real estate transaction deadline.
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