No health-based violations on EPA record since 2016.
Serves about 5,092 people (1,845 connections) with groundwater from its own wells.
From EPA's record for FL2100610. PurityMap is independent of Keystone Postmaster Grid.
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No health-based violations in the last 10 years, from EPA's SDWIS compliance database.
EPA required this system to test for 30 unregulated and emerging contaminants, from February 2025 to August 2025.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Lithium | < 9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-02-05 to 2025-08-26 | UCMR5 Analytical Results: KEYSTONE POSTMASTER GRID (FL2100610) |
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Get PurityMap updates about this water system.
Follow this water →Keystone Postmaster Grid's phone number on EPA record is 904-213-2477. Its mailing address is 3176 OLD JENNINGS ROAD, MIDDLEBURG, FL 32068-3907.
According to EPA's record, Keystone Postmaster Grid uses groundwater from its own wells.
No health-based violations on EPA record since 2016. The record comes from EPA's SDWIS compliance database.
The 90th-percentile lead result in Keystone Postmaster Grid's latest lead and copper round, which ended in December 2023, was 2.3 µg/L, below the federal action level of 15 µg/L.
PurityMap has no verified website for Keystone Postmaster Grid. Its phone number on EPA record is 904-213-2477. Its mailing address on EPA record is 3176 OLD JENNINGS ROAD, MIDDLEBURG, FL 32068-3907. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.