History of PFAS

In May 2016, the EPA established a drinking water health advisory for PFOA and PFOS at 70 ppt for the combined total of the two.

In 2016 the State of Connecticut Department of Public Health (CT DPH) established a stricter drinking water health advisory for the combined total of the five compounds PFOA, PFOS, PFHxS, PFHpA, and PFNA at 70 ppt. 

Subsequent refinements in the testing methodology resulted in lower method detection limits as shown above (2018/2019). These refined methods were used for recent testing by the FTDWD in 2018 and 2019.

The CT DPH Drinking Water Section (DWS) in the circular letter 2018-20 on September 27, 2018 stated:

“It has become evident that the Perfluoroalkyl Substances (PFAS) data submitted to the Environmental Protection Agency (EPA) for the Third Unregulated Contaminant Monitoring Rule (UCMR3) was not sufficient to evaluate the safety of CT’s public drinking water relative to the State’s Drinking Water Action Level (DWAL) of 70 parts per trillion for the sum of the concentrations of perflurooctanoic acid (PFOA) + perfluorooctane sulfonate (PFOS) + perfluorohexane sulfonate (PFHxS) + perfluoroheptanoic acid (PFHpA) + perfluorononanoic acid (PFNA).”

In that letter, the CT DPH required that public water supplies that submit Water Supply Plans, update their source water protection inventories to include potential PFAS users and sources by March 31, 2019. Additionally the CT DPH recommended that all sources of public drinking water be tested for PFAS.

In the fall of 2018 the FTDWD reviewed the Interstate Technology Regulatory Council (ITRC) documents on the historical uses of PFAS and available records of past industry near the wellfield, and found potential locations where PFAS might have been stored and/or used. Based upon the DPH recommendation and this review, the FTDWD decided to sample all the sources as soon as feasible. On December 12, 2018 samples were collected from all four reservoirs, wells 1, 3 and 5, (wells 2 and 4 needed repair) the treated surface water, and the treated well water. The samples were analyzed, as recommended by the CT DPH, for PFOA, PFOS, PFHxS, PFHpA, PFNA and PFBS. Results of these samples were received in early January 2019. The FTDWD contacted CT DPH as requested in early January 2019 to inform them that some of the results exceeded half of the 70 ppt CT DPH health advisory. The FTDWD provided a spreadsheet of the test data to DWS on February 22, 2019. Some of these tests were repeated on January 9, 2019 with new samples to confirm the results. These results were received on February 1, 2019 and confirmed the original test data.

Subsequently, the FTDWD stopped use of wells 1 and 2 which had the highest PFAS concentrations and reduced use of the other wells in mid-January. The FTDWD Well Management Rules were formalized by the FTDWD On April 25, 2019 to minimize PFAS from the well field. These rules include:

In the Sixth Five-Year Review Report published September 26, 1997 for the Kellogg-Deering Well Field, the EPA recommended testing for PFAS at the superfund site (https://semspub.epa.gov/work/01/621483.pdf). On January 4, 2019 the FTDWD contacted the EPA to find out if they had analyzed any samples from the Kellogg-Deering Superfund site for PFAS. Because the FTDWD UCMR3 tests had not detected PFAS, the EPA had not yet tested for PFAS at that site.

In early July, 2019 The FTDWD provided the EPA with additional PFAS sampling data and followed up on EPA testing for PFAS at the Kellogg-Deering Superfund site. The EPA indicated on July 22, 2019 they are seeking the timely collection of samples for PFAS analysis from selective monitoring points in areas of the Site. FTDWD anticipates that EPA testing will occur in September/October, 2019.

While the source of the PFAS contamination at the well field is not fully understood, in March 2019 the FTDWD took advantage of the application process for the CT DPH Drinking Water State Revolving Fund (DWSRF). The fund provides long-term low interest loan and partial subsidization for infrastructure projects. The FTDWD is evaluating options and will continue to monitor and sample for PFAS to ensure that the FTDWD can respond quickly if the water quality changes. The goal of the FTDWD is to provide the highest quality water to our customers. 

Additional samples have been collected each month since April 2019 at varying locations and have been analyzed for 14 different PFAS compounds. Of the additional 8 PFAS tested for, the only additional PFAS detected is PerfluoroHexatonic Acid (PFHxA) at 6 ppt, just above the < 5 ppt method detection limit.