EPA Study Results

Tampa Bay Water tested the regional drinking water supply for PFAS, alongside its member utilities during EPA’s nationwide study. This helps EPA set regulations for PFAS and it helps Tampa Bay Water determine if treatment is needed, where treatment is needed and how much treatment is needed. Tampa Bay Water and five of its members began testing in July 2023. The City of Tampa began testing in January 2023.

Find out more about PFAS on our main PFAS page.

Things to know about these results

Note: parts per trillion are spelled out in all cases on this page. The ppt acronym is used on our main PFAS page.

  • The six PFAS in the sampling results tables are those for which EPA has set Maximum Contaminant Levels. The EPA study includes a total of 29 PFAS. Links to the full tables are provided below.
  • PFOA and PFOS Maximum Contaminant Levels are each 4.0 parts per trillion.
  • EPA's Hazard Index is a calculation used to determine combined levels of four PFAS. The Hazard Index Maximum Contaminant Level is 1. The individual health-based values for each substance used in the calculation are:
    • PFBS - 2,000 parts per trillion
    • PFHxS - 9 parts per trillion
    • PFNA - 10 parts per trillion
    • HFPO-DA (Gen X) - 10 parts per trillion
  • ND means no detectable levels of PFAS were found using EPA Methods 533 and 537.1.
  • Tampa Bay Water’s member utilities use contract laboratories to perform testing for the EPA study. EPA prohibits contract laboratories from reporting detections below its minimum reporting level so results reported by Tampa Bay Water may appear different from our members’ contract labs in some cases. Tampa Bay Water is voluntarily testing drinking water supplies during the EPA study in its state-certified laboratory and is not subject to EPA reporting requirements.
    • EPA reporting requirements are intended to ensure data quality consistency from the many contributing nationwide laboratories that have varying capabilities. For more information please see the Fifth Unregulated Contaminant Monitoring Rule | US EPA.
    • Additionally, when measuring at parts per trillion, results may vary slightly due to differences in samples, equipment, analytical instruments and technicians. This is common and is one of the reasons why EPA bases its limits on annual averages.

First Quarter Sampling Results

EPA Fifth Unregulated Contaminant Monitoring Rule Study Sampling Results in Parts Per Trillion
First Quarter (of four quarters) – July 2023

Quarter 1 PFAs testing results

Download the full results table.

Second Quarter Sampling Results

EPA Fifth Unregulated Contaminant Monitoring Rule Study Sampling Results in Parts Per Trillion
Second Quarter (of four quarters) – October 2023

Quarter 2 PFAs Testing Results

Download the full results table.

Third Quarter Sampling Results

EPA Fifth Unregulated Contaminant Monitoring Rule Study Sampling Results in Parts Per Trillion
Third Quarter (of four quarters) – January 2024

Quarter 3 PFAs testing results

Download the full results table.

Fourth Quarter Sampling Results

EPA Fifth Unregulated Contaminant Monitoring Rule Study Sampling Results in Parts Per Trillion
Fourth Quarter (of four quarters) – April 2024

Quarter 4 PFAs testing results

Download the full results table.

Visit your local utility's PFAS page: