2016 and 2017 Milestones/Activities
As of December 31, 2017, approximately 12.7 million gallons of petroleum product has been recovered, and over 5.5 billion gallons of groundwater has been recovered and treated from the three sites comprising the Greenpoint Petroleum Remediation Project. In 2017, the project recovered a total of approximately 130,000 gallons of product, while recovering and treating over 360 million gallons of groundwater to Clean Water Act standards.
ExxonMobil Greenpoint Petroleum Remediation Project (EMGPRP – S224150)
Upgrades to both the on-site recovery and containment system (RCS) and the off-site free-product recovery system (ORS) were completed in 2014. As part of an on-going assessment, ExxonMobil continued to evaluate light non-aqueous phase liquid (LNAPL) flux transmissivity in 2016 and 2017 to evaluate the performance of the current recovery systems and assess future free-product recoverability. Transmissivity is an evaluation of the rate at which free-product will flow through the subsurface (or into a monitoring well) at a specific groundwater gradient. This investigation evaluated transmissivity using 3 different methods (bail-down testing, dye tracer testing, and recovery system operational data). ExxonMobil also evaluated various field methods (such as soil sample TPH analysis, shake tests, collection of undisturbed soil cores for soil and fluid characterization, and visual inspection in test pits) to identify mobile free product.
ExxonMobil began expansion of the soil vapor extraction (SVE) system in OU-7 and OU-8 in 2015. Soil vapor extraction is a remediation method where a vacuum is applied to the ground and contamination is removed as a gas. During 2015, ExxonMobil completed the installation of piping and instrumentation within the new installed SVE well vaults and performance of pressure testing throughout the SVE network. An expansion of teh SVE system in OU-7 and OU-8 was completed in 2016. Following the expansion, ExxonMobil conducted a vapor enhanced recovery pilot study in OU-5, OU-7, and OU-8 at recovery wells RW-18, RW-21, and RW-24 through 2017. Based on the results of this study, vapor enhanced recovery technology continues to operate at two of the recovery wells (RW-18 and RW-24) as part of normal operations.
Numerious remdial activities occured in ou-4 during 2016 and 2017. In may 2016, ExxonMObil begain oil-water separator closure activities began on the former terminal property. ExxonMobil dewatered the oil-water separator structure and solidified the remaining sludge prior tho its removal from the site. Once empty, the structure was backfilled and compacted prior to the installation of teh final cap/cover and site restoration. The closure work was completed in May 2017.
Pipe removal activities took place within the Kingsland Yard in OU-4 beginning in fall 2016 and was completed in 2017. The purpose of this work was to remove any remaining former terminal piping located beneath the current infrastructure of the site. This activity was needed to facilitate the installation of new stormwater drainage piping system on the property. The new stormwater system includes catch basins, conveyance piping, a hydrodynamic separator, and a filter unit to treat stormwater prior to discharge from teh property. Construction for the new stormwater system began in May 2016 and is expected to be completed in 2018.
ExxonMobil submitted an Interim Remedial Measures Work Plan to NYSDEC in November 2016 to delineate and excavate areas where TPH concentrations exceed site-specific criteria. NYSDEC approved the work plan in February 2017, delineation activities began in fall 2017, and excavation activities in the North Henry Yard (OU-4) commenced in November 2017. This work continued into 2018.
In September 2016, ExxonMobil installled a new recovery well, RW-M, within OU-8. In May 2017, ExxonMobil submitted a request to NYSDEC to shutdown recovery well RW-J (located within OU-7) due to site modifications being made by the property owner. As part of NYSDEC's approval for teh shutdown, one year of hydraulic monitoring was required post-shutdown of the surrounding monitoring well network. RW-J was shutdown on May 18, 2017 and ExxonMobil began the one year monitoring period.
Former Paragon Oil Terminal (S224083) and Apollo Street Creek Parcels (S224122)
Chevron-Texaco expanded the from 13 to 17 product recovery wells in 2016 as part of upgrades to the current product recovery system. Chevron-Texaco also continued to manually remove product from one upper bulkhead monitoring well (CMW-54) and five lower bulkhead monitoring wells (CMW-57, CMW-58, MW-67, MW-68, and MW-77) on a weekly basis through 2015. During the 2016 and 2017 semiannual warehouse shutdown events, free-product is also recovered from indoor monitoring wells.
In addition to routine recovery well and treatment system inspections, treatment system maintenance also included fluid removal and cleaning of the backwash water tanks, pre-oil-water separator tank, and the oil-water separator on a semi-annual basis. Non-routine maintenance in 2016 and 2017 included abandoning and disposal of former terminal piping from the lower bulkhead, installation of a new regulator/cycle counter at CMW-69R, and a full system cleanout.
As part of the treatment system operation and maintenance, Chevron-Texaco routinely performs bulkhead inspections and maintains the boom containment systems along both the former Paragon Oil Terminal and Apollo Street bulkheads. Chevron-Texaco continued to reseal bulkhead seams with a marine epoxy and adjusting containment boom on a quarterly basis in 2016 and 2017. Four sheens were observed within containment booms along the creek bulkhead during oversight events in 2016 and 2017. During teh same time period, four sperate sheens were also observed outside the containment boom system, some of which appear to be the result of upsteam sources not related to the Greenpoint product plume.
Indoor monitoring wells in the Empire Merchants and the Apollo Street warehouses are inspected monthly, with slab maintenance activities (cracks, seams, and joints are repaired and resealed) are performed twice a year during semiannual warehouse shutdowns to ensure structural integrity of the building and prevent the possibility of vapor intrusion. Ambient air quality in the warehouses was monitored on a semi-annual basis, with a total of 18 air samples collected across the site for methane and volatile organic compounds to ensure air quality inside the building is safe.
As part of the Expanded Extraction and Treatment with Vapor-Phase Recovery System, Chevron-Texaco installed three new recovery wells (CMW-74R, CMW-75R, and PW-2R) in 2016. Remedial improvements continued throughout 2016 and 2017, with the Expanded Extraction and Treatment with Vapor-Phase Recovery System includes the following elements:
- Expansion of the product recovery and treatment system.
- The addition of a vapor-phase recovery at product recovery wells.
- Catalytic oxidation for vapor phase treatment.
- Monitored Natural Attenuation (MNA) of dissolved groundwater contamination.
- Continued use of granular activated carbon (GAC) to treat groundwater contamination.
- Continued performance and maintenance of existing containment and capping controls.
Work associated with the recovery system expansion and upgrade is expected to continue through 2018.
KM Terminal (formerly BP Terminal) (S224082)
In 2016 and 2017, KM continued the operation of the on-site groundwater treatment system that was installed in 2014. The treatment system had a run time of more than 90% in 2016 and 2017. The majority of the system downtime in 2015 was to perform maintenance and make modifications to optimize the system run time.
Due to persistent LNAPL thicknesses greater than 3 feet in monitoring wells OW-11 and MW-6, both wells were originally outfitted with a temporary product recovery systems in August 2015, but both wells were outfitted with new recovery equipment in early 2017. Product recovery from these wells operate independently of the full scale recovery system. In 2017, OW-11 recovered approximately 300 gallons, while MW-6 recovered approximately 1,000 gallons.
In addition to routine inspections and maintenance, KM made several modifications to its product recovery system at the site in 2016 and 2017 including:
- Replacement of piping between the oil-water separator, the transfer pump, and the equilization tank to improve water flow. KM also installed a large impeller in the transfer pump to improve water flow though the treatment system bag filters.
- Replacement of PVC piping between the equilization tank and teh air strippers due to fouling.
- Abandonment of MW-16 in June 2017.
- Installation of MW-25 in September 2017.
- Intragration of recovery wells RW-11 and RW-12 to the on-site compressor.
- Modification of pump in RW-14 to improve product recovery.
KM continued to perform weekly methane screening at various locations on the Terminal Property and performed an annual site-wide vapor screening events in April 2016 and May 2017 to monitor the levels of methane, oxygen, carbon dioxide, carbon monoxide, hydrogen sulfide, balance, lower explosive limit, barometric pressure, and relative pressure across the site. Two additional sub-slab vapor monitoring points were installed inside the former Sprague building to replace former points within the building that had been destroyed. No vapor readings were identified by the screening events that required further action in 2016 and 2017.