Surface Water-Sourced Community Drinking Water Systems

Sampling and analyses for community drinking water systems where raw water is supplied by surface waters has been completed by BOW staff. The results are presented as follows:

• Exhibit 1 – Table of Nomenclature for PFAS Analytes Covered under EPA Methods 537.1 and 533
• Exhibit 2 – Frequency Distributions of PFOA and PFOS Data from Surface Water-Sourced Plants
• Table 1 – PFOA and PFOS Data by EPA Methods 537.1 and 533 from Surface Water-Sourced Plants
• Table 2 – Other PFAS Data by EPA Method 537.1 from Surface Water-Sourced Plants
• Table 3 - Other PFAS Data by EPA Method 533 from Surface Water-Sourced Plants
• Table 4 – Quality Control Data (Field Blank Results) from SCDHEC Sampling
• Table 5 – PFOA and PFOS Data by River Basin for Surface Water-Sourced Plants
• Table 6 – Summary of PFOA and PFOS Data by River Basin for Surface Water-Sourced Plants
• Table 7 – PFOA and PFOS Data Provided by Drinking Water Utilities for Surface Water-Sourced Plants
  • Table 7A - PFOA and PFOS from SCDHEC Sampling of Surface Water Sourced Community Drinking Water Systems that Provided PFAS Data to SCDHEC
• Table 8 – Other PFAS Data Provided by Drinking Water Utilities for Surface Water-Sourced Plants
  • Table 8A - Other PFAS Data (Excluding PFOA and PFOS) by USEPA Method 537.1 from SCDHEC Sampling of Surface Water Sourced Community Drinking Water Systems that Provided PFAS Data to SCDHEC
  • Table 8B - Other PFAS Data (Excluding PFOA and PFOS) by USEPA Method 533 from SCDHEC Sampling of Surface Water Sourced Community Drinking Water Systems that Provided PFAS Data to SCDHEC

Groundwater Supplements to Surface Water-Sourced Community Drinking Water Systems 

Sampling and analyses for community drinking water systems where groundwater is also used as a source of raw water is underway by BOW staff.  Results reported thus far are presented as follows:

• Table 9 - PFOA and PFOS Data from Groundwater Wells Used by Drinking Water Utilities that have Surface-Sourced Plants 
• Table 10 - Other PFAS Data from Groundwater Wells Used by Drinking Water Utilities that have Surface-Sourced Plants
• Table 11 - Quality Control Data from Groundwater Wells Used by Drinking Water Utilities that have Surface-Sourced Plants

Ground Water-Sourced Community Drinking Water

• Exhibit 3 - PFAS Data for Groundwater Sourced Systems
• Table 12 - PFAS from Groundwater Sourced Systems
• Table 13 - Other PFAS Data for Groundwater Sourced Systems
• Table 14 - Quality Control Information from Groundwater Sourced Systems

Some Observations as of December 2021:

• 113 Community water systems sampled
  • 60 surface water treatment plants + 47 supplemental wells
  • 53 ground water systems with 270 wells
• USEPA Lifetime Drinking Water Health Advisory for PFOA and PFOS - 70 nanograms per liter (parts per trillion)
• Number of Exceedances of the USEPA Lifetime Drinking Water Health Advisory - zero (0)
• Surface water:
  • Maximum PFOA Concentration Measured - 18 ng/L
  • Maximum PFOS Concentration Measured - 16 ng/L
  • Maximum Combined PFOA and PFOS Measured - 32 ng/L
• Ground water:
  • Maximum PFOA Concentration Measured - 32 ng/L
  • Maximum PFOS Concentration Measured - 17 ng/L
  • Maximum Combined PFOA and PFOS Measured - 49 ng/L

Continuing Work:

• SC DHEC continued sampling of remaining Community drinking water systems supplied by ground water.
• Begin sampling under BOW Strategy for ambient surface waters perspective, including fish tissue.

Resources

• EPA National Primary Drinking Water Regulations

*Page last updated 3/22/2023