Perfluoroalkyl compounds (PFCs) are a family of persistent emerging contaminants with widespread environmental occurrence in a variety of media, including aquatic systems (Ahrens 2011, Ferrey et al. 2012, Post et al. 2013). They have unique properties that make them useful in a wide range of products and industrial applications (Lindstrom et al. 2011, Post et al. 2012). PFCs are soluble in water, which aids their ability to disperse in the environment (Eschauzier et al. 2012, NJDEP 2014). PFCs are currently unregulated contaminants in drinking water. The U.S. Environmental Protection Agency (USEPA) has developed a Public Health Advisory of 0.4 micrograms per liter (μg/L) (400 nanograms per liter (ng/L)) for short-term (defined by USEPA IRIS as up to 30 days) exposure to perfluorooctanoic acid (PFOA), one of the most common PFC compounds found in the environment (USEPA 2009). The New Jersey Department of Environmental Protection (NJDEP) has also issued health-based drinking water guidance level of 0.04 ug/L (40 ng/L). NJDEP’s guidance is intended to protect from chronic (lifetime) exposure, normally defined as 70 years, consistent with other New Jersey drinking water guidance values, drinking water standards, and ground water standards (Post et al. 2009)
In a 2009 statewide study of perfluoroalkyl compound (PFC) occurrence in public water supplies conducted by NJDEP, the concentration of the PFC compound perfluorooctanoic acid (PFOA) was higher in a drinking water intake along the South Branch Metedeconk River in Ocean County than in the other raw surface water sources tested. The Brick Township Municipal Utilities Authority (BTMUA), which relies on the Metedeconk River as its primary source of water supply, subsequently initiated a PFC source track down study in collaboration with the NJDEP Division of Science, Research, and Environmental Health. The data collected from a series of sampling events show that low levels of various PFCs are present in the study area and likely originate from a number of sources. However, BTMUA documented a localized area of high-level PFC contamination along the South Branch Metedeconk River in Lakewood Township. A groundwater contamination plume emanating from an industrial park on the south side of the river is suspected to be the principle source of PFCs observed in the Metedeconk River and the BTMUA intake samples. Groundwater PFOA levels were found to be as high as 70,000 ng/L in this area. While various PFCs were detected in water samples throughout the study area, and particularly in groundwater samples, PFOA is the primary contaminant of concern with respect to South Branch Metedeconk River water quality and the BTMUA water supply.
Discussion
The primary PFC found in the BTMUA drinking water intake was PFOA, and PFOA was also the primary PFC found high in concentrations in the study samples. Various other PFCs were detected in water samples throughout the source track down study area and were most pronounced in the groundwater samples.
During the course of the study, numerous environmental records and databases were reviewed and field surveys were conducted to identify and document any indications of dumping, negligent business practices, or poor housekeeping. Several suspected illicit discharges were identified, including process water from granite manufacturing facilities, recycled water from a commercial car wash, and vehicle wash water from the lots of large commercial auto dealerships. The information gathered offered few leads as to the PFC contamination source. Specific leads were either rejected based upon the sampling results or deemed insignificant given their magnitude relative to the observed PFC levels in the South Branch Metedeconk River. The locations of groundwater samples with extremely high PFC concentrations were used to isolate the mostly likely PFC sources to the parcel level. The plume likely originates in the Lakewood Industrial Park, and a small location within this industrial park has been identified as a probable source. Based upon the assumption that groundwater in the area generally follows the surface topography and flows towards the River, the contamination source is most likely confined to one of three possible properties located in Lakewood Township on the south side of Swarthmore Avenue and east of Lehigh Avenue.
A facility located on these three properties manufactures industrial fabrics, composites, and elastomers, and uses or produces products that contain PFCs. In light of the groundwater sampling data, and in comparison to the other facilities in the area, this facility appears to be the most probable source and warrants further investigation. However, some other, as yet unknown source cannot be ruled out. In the event that groundwater flow assumptions are incorrect for this area, several other properties align with the groundwater plume area on the north side of Swarthmore Avenue. None of those properties appear to be manufactures or user of PFC compounds. It is unclear how long PFCs have been contaminating the groundwater in this area. However, during Sampling Event 8, a split sample from one site was analyzed by USEPA’s National Exposure Research Laboratory in North Carolina and evaluated for the presence of branched and linear PFCA isomers (Strynar and Lindstrom 2013). The presence of both linear and branched isomers and the presence of both even and odd numbered carbon chains suggest an older source of contamination (Benskin et al. 2012, Strynar 2014).
The process that produced both branched and linear isomers and a relative mix of even and odd numbered carbon chains, known as electrochemical fluorination, was the dominant manufacturing process between the 1950s and 2002 and has since been phased out. Upon completion of this study and receipt of the final report, the NJDEP Site Remediation and Waste Management Program has contacted the potential responsible party to take appropriate remedial action