Concern is growing around the presence of Perfluoro and Polyfluoro Alkyl Substances (PFAS)—a category of chemicals used as firefighting foam and for consumer products including Teflon®, water-resistant material, cleaning products, etc. Many states have developed guidelines for the detection, management, and remediation of these chemicals; NY and NJ are in the process of promulgating standards for multiple PFAS compounds. These standards mainly apply to groundwater and drinking water. However, some states including NY are also evaluating standards for PFAS in the soil.


On March 13, 2019, the NJDEP established an interim specific ground water quality standard for perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) of 0.01 ug/L (10 ng/L).


In January of 2020, The New York DEC issued the Guidelines for Sampling and Analysis of Per- and Polyfluoroalkyl Substances (PFAS) Under NYSDEC’s Part 375 Remedial Programs. The DEC also issued interim PFAS standards for drinking water.


SESI Investigation Activities
SESI has conducted multiple PFAS soil and groundwater investigations at Sites in NY in accordance with the NYSDEC requirements using analysis with Modified USEPA Method 537 for 21 PFAS. We are presenting here six representative projects with 3 different population concentrations: urban (Brooklyn and Bronx); suburban (New Rochelle, and Peekskill); and rural (Catskills).


Soil Analysis
Soil analysis resulted in PFAS detection in 75 out of 76 Brooklyn site samples, 66 out of 88 Bronx site samples , 117 out of 117 in the Peekskill site samples, 25 out of the 60 New Rochelle site samples, and in 9 out of 11 Catskills site samples. It is worth noting that the soil samples at the Catskills site were biased towards the areas of the historic commercial activities, which included hotel and entertainment. The Brooklyn site had the highest number of PFAS constituents detected per sample and the highest average concentration. The highest detected concentrations in Brooklyn ranged between 13 and 8.9 ug/kg (ppb). The highest detected concentrations in the Bronx and Peekskill was PFOS at 62.6 ppb and 11.1, respectively. The Catskills site soil samples had the lowest number of PFAS constituents detected per sample and the lowest average concentration among the sites.



Groundwater Analysis
Groundwater results showed similar trends but the PFAS compounds detected in groundwater were different than the compounds detected in soils. The Brooklyn groundwater sampling results identified PFAS in every well with concentration ranging from 0.29 to 75.5 ng/l (ppt). The Peekskill groundwater identified PFAS in every well with concentration ranging from 0.91 to 42.5 ng/l (ppt). The Bronx groundwater results ranged from 0.533 to 111 ng/l (ppt). The PFAS detections at the Catskill site were limited to within the area of the historic commercial operations. Generally, the detected concentrations in the Catskills site wells were lower than the concentrations at other urban or suburban sites.



The history of the sites discussed above does not include any uses of concentrated PFAS compounds, such as firefighting or manufacturing. The sample of sites presented is relatively small, but it represents sites with a variety of historic uses and population concentration. Based on this limited sample, PFAS appears to be more common in areas with higher populations, where daily common consumer products have higher chance of impacting the environment.


While many states have not determined guidelines, they are likely to follow in line. Understanding the sources, transport, and fate of PFAS detects during the remediation stages is crucial for any future remedy to meet the regulatory limits and requirements of these compounds. A conceptual site model detailed with extensive site history will be key in evaluating PFAS impacts. If you believe that PFAS materials may be present at your site, discuss with Fuad Dahan about testing and remediation.

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