Site Description This site is now occupied by a residential condo development known as the 5th Street Lofts built by Toll Brothers. This site is approximately 1 acre in size. Past industrial uses include: varnish works, an ink factory, metal castings and plating, cleaners and dyers and a dry cleaner. Hazardous materials associated with the historical uses include: industrial solvents, lubricating and cutting oils, metal polishing material, plating bath solutions, paint and painting products and dye products. In addition, Sanborn maps indicate the presence of two (2) gasoline storage tanks, twenty-two (22) Varnoline storage tanks, three (3) solvent tanks and one (1) 10,000 gallon #6 fuel UST. Completed investigations include Phase I and Phase II Investigations (submitted as part of the BCP application), and Remedial Investigation (RI Report dated September 2008).
Site Environmental Assessment Remedial Investigations conducted at the site confirm light non-aqueous phase liquid (LNAPL) is present at the site (primarily on the western portion of the site) in the perched groundwater that overlies a semi-impervious clay peat layer which is at 10 to 12 feet below ground surface. Contaminants of concern including volatile organic compounds (VOCs), semi volatile organic compounds (SVOCs), and heavy metals have been detected on subsurface soil and groundwater. The contamination identified at the site was associated with the historic on-site manufacturing operations. Up to 3.6 feet of LNAPL was detected in perched groundwater. VOCs detected in groundwater exceed groundwater standard includes acetone, ethylbenzene, isopropylbenzene, benzene, toluene, vinyl chloride with concentration up to 340 µg/l, 150 µg/l, 150 µg/l, 100 µg/l, 22 µg/l, 5.4 µg/l respectively. SVOCs were detected in subsurface soils that exceed Unrestricted Use Soil Cleanup Objectives (UUSCOs) including naphthalene, phenanthrene, and fluorene with maximum concentration of 230 µg/kg, 130 µg/kg and 53 µg/kg, respectively; SVOCs were detected in groundwater that exceed the groundwater standards including naphthalene, acenaphthene, fluorene, phenanthrene, and benzo(a)anthracene with maximum concentration of 3400 µg/l, 290 µg/l, 250 µg/l, 2100 µg/l, and 24 µg/l, respectively. In addition, cyanide is present in the groundwater with concentration up to 690 µg/l which exceed the groundwater standard (200 µg/l). Metals were detected at concentrations exceeding their respective UUSCO throughout the site, including lead, mercury, arsenic, copper, zinc, acetone, and ethyl benzene were detected in subsurface soil with concentration up to 4490 mg/kg, 11.3 mg/kg, 19 mg/kg, 501 mg/kg, 401 mg/kg, 0.69 mg/kg, 6.9 mg/kg respectively. Contaminants such as Tetrachloroethylene (PCE), and methylene chloride were detected in soil vapor/sub-slab samples. Individually, PCE and methylene chloride were detected at 136 µg/m3 and 274 µg/m3 respectively. The site poses a significant threat to the environment.
Site Health Assessment Although low levels of volatile organic compounds are present in on-site soil vapor, the site is unoccupied and all site buildings have been demolished thus eliminating the potential for current exposures to site-related contaminants in indoor air. In addition, contaminants detected in soil vapor at the site are below levels that would require mitigation and are not likely to impact off-site properties. Since all remaining soil contamination at the site is covered with either concrete slabs or plastic and the site is fenced, the potential for people to come in contact with contaminated soil has been minimized. Also, ingestion of contaminants in drinking water is unlikely as area homes and businesses are served with public water.