NC PFAST Quantitative Screening Results for Raw Drinking Water

SAMPSON CO WTR DIST II (NC0382070), 2019-10-16

Disclaimer: The PFAS measurements reported here represent initial laboratory findings that have not been subjected to full validation and quality assurance/quality control procedures and should be considered preliminary.

As part of the North Carolina Per and Polyfuoroalkyl Substances Testing (PFAST) Network statewide sampling effort (ncpfastnetwork.com), a raw water sample collected from SAMPSON CO WTR DIST II (NC0382070) on 2019-10-16 by the Knappe Lab was analyzed for 36 PFAS chemicals by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Concentrations of individual PFAS are reported in units of parts-per-trillion (ppt, i.e., nanogram of chemical per liter water).

PFAS compounds are not currently regulated as drinking water contaminants by the United States Environmental Protection Agency (US EPA) or the North Carolina Department of Environmental Quality (NC DEQ) and thus the measurements reported here are not intended to be used in enforcement actions. The US EPA has established a lifetime health advisory level (HAL) of 70 ppt for combined perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in drinking water. In addition, the NC DHHS has established a provisional health goal based on risk assessment for GenX in drinking water of 140 ppt. These advisory levels can serve as reference values when evaluating PFAS concentrations reported below for raw drinking water.

Reporting Limit (RL): This is the lowest concentration that can be confidently quantified in water samples for an individual PFAS chemical. This level is a function of instrument sensitivity, reproducibility, and precision. The RL typically (but not always) represents the lowest concentration point on the calibration curve, and it is always higher (often much higher) than the method detection limit (MDL) for a given PFAS analyte.

Sum of PFOS and PFOA

PFOA and PFOS were both below their respective reporting limits.

GenX

GenX was not detected above its reporting limit.

Total PFAS

No PFAS were detected above reporting limits.

Summary of findings

Figure 1: Concentrations of individual PFAS compounds.

Table 1 Concentrations of PFAS compounds detected in parts-per-trillion (ppt). Gray values indicate compounds below the reporting limit (RL). Bold rows indicate occurence in excess of the EPA Health Advisory Limit (HAL) for PFOS + PFOA of 70 ppt.

Analyte Name Abbreviation CAS Registry Number Concentration (ppt) RL (ppt)
Fluoroalkyl sulfonamides (FASAs)
Perfluorobutane sulfonamide PFBSA 30334-69-1 <RL 2
Perfluorohexane sulfonamide PFHxSA 41997-13-1 <RL 1
Perfluorooctane sulfonamide PFOSA 754-91-6 <RL 5
N-methyl perfluorooctanesulfonamidoacetic acid NMeFOSAA 2355-31-9 <RL 10
N-ethyl perfluorooctanesulfonamidoacetic acid NEtFOSAA 2991-50-6 <RL 50
Fluorotelomer Sulfonates
4:2 Fluorotelomer sulfonic acid 4:2 PFS 757124-72-4 <RL 1
6:2 Fluorotelomer sulfonic acid 6:2 PFS 27619-97-2 <RL 10
8:2 Fluorotelomer sulfonic acid 8:2 PFS 39108-34-4 <RL 5
10:2 Fluorotelomer sulfonic acid 10:2 PFS 120226-60-0 <RL 20
Perfluoroalkylcarboxylic acids (PFCAs)
Perfluorobutanoic acid PFBA 375-22-4 <RL 1
Perfluoropentanoic acid PFPeA 2706-90-3 <RL 5
Perfluorohexanoic acid PFHxA 307-24-4 <RL 5
Perfluorooctanoic acid PFOA 335-67-1 <RL 1
Perfluorononanoic acid PFNA 375-95-1 <RL 2
Perfluorodecanoic acid PFDA 335-76-2 <RL 2
Perfluoroundecanoic acid PFUnDA 2058-94-8 <RL 20
Perfluorododecanoic acid PFDoDA 307-55-1 <RL 10
Perfluorotridecanoic acid PFTrDA 72629-94-8 <RL 2
Perfluorotetradecanoic acid PFTeDA 376-06-7 <RL 1
Perfluoroalkylether Acids (PFEAs)
Perfluoro-2-methoxypropanoic acid PMPA 377-73-1 <RL 5
1,1,2,2-tetrafluoro-2-(1,2,2,2-tetrafluoro-ethoxy)ethane sulfonic acid NVHOS N/A <RL 5
Perfluoro-2-propoxypropanoic acid GenX 13252-13-6 <RL 2
Propanoic acid, 3-[1-[difluoro(1,2,2,2-tetrafluoroethoxy)methyl-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro- Hydro-EVE acid 773804-62-9 <RL 2
2,2,3,3,4,5,5,5-4-(1,1,2,2-tetrafluoro-2-sulfoethoxy)pentanoic acid Nafion by-product 4 N/A <RL 5
Ethanesulfonic acid, 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoro- Nafion by-product 1 29311-67-9 <RL 2
Ethanesulfonic acid, 2-[1-[difluoro(1,2,2,2-tetrafluoroethoxy)methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoro- Nafion by-product 2 749836-20-2 <RL 1
Perfluoroalkylsulfonic Acids (PFSAs)
Perfluorobutanesulfonic acid PFBS 375-73-5 <RL 1
Perfluoropentanesulfonic acid PFPeS 2706-91-4 <RL 1
Perfluorohexanesulfonic acid PFHxS 355-46-4 <RL 1
Perfluoroheptanesulfonic acid PFHpS 375-92-8 <RL 1
Perfluorooctanesulfonic acid PFOS 1763-23-1 <RL 1
Perfluorononanesulfonic acid PFNS 68259-12-1 <RL 5
Perfluorodecanesulfonic acid PFDS 2806-15-7 <RL 20
Zwitterions
N-(3-dimethylaminopropan-1-yl)perfluoro-1-hexane-sulfonamide N-AP-FHxSA 50598-28-2 <RL 10
N-[3-(perfluoro-1-hexanesulfonamido)propan-1-yl]-N,N,N-trimethylammonium N-TAmP-FHxSA 38850-51-0 <RL 5
N-(carboxymethyl)-N,N-dimethyl-N-[3-(1H,1H,2H,2H-perfluoro-1-octanesulfonamido)propan-1-yl]ammonium N-CMAmP-6:2FOSA (6:2 FTAB) 34455-29-3 <RL 2