Maunabo Urbano

PFAS monitoring results for a public water system in Puerto Rico

PR0004815UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
4.8Highest PFOS result, ppt
0.002Highest Hazard Index
360Results
PWSID
PR0004815
State
Puerto Rico
System type
community water system (CWS)
Population served
9,380
City
Maunabo
Counties
Maunabo Municipio
Primary source water
surface water
UCMR 5 sampling
2025-01-21 to 2025-10-22 · 5 entry point(s) · water types: GW;SW
Service-area boundary
authoritative

PFOS 1–3 × its limit highest single result
PFOS 1–3 × its limit worst entry-point average

These are monitoring results collected under EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) at entry points, where treated water enters the distribution system; they are not tap-water samples. They are not compliance determinations: compliance with EPA's 2024 PFAS limits is judged on running annual averages of compliance monitoring, required from 2029, so a single UCMR 5 result at or above a limit is not a violation. “< MRL” means the compound was not quantified at EPA's minimum reporting level; it does not mean zero.

Compared with EPA's 2024 values

Highest single resultWorst entry-point average*Limit
PFOA (ppt)<MRL04
PFOS (ppt)4.84.44
Hazard Index0.0020.0011.0†

“<MRL” = every result for the compound was below its reporting limit. * Mean of all samples at each entry point with non-detects = 0 (EPA compliance convention; the Hazard Index also uses non-detects = 0); a screening comparison, not a formal running annual average. † Rescission proposed May 2026. PFOA/PFOS MCL 4 ppt (2024 NPDWR, in effect). PFHxS, PFNA, HFPO-DA (10 ppt each) and the Hazard Index (1.0) are 2024 NPDWR values; EPA proposed rescinding them on 18 May 2026 (comment period closed 20 Jul 2026).

No Puerto Rico PFAS drinking-water standard in effect or proposed as of 2026-10-17: No Puerto Rico-specific PFAS drinking-water standard identified (federal NPDWR applies).

Sampling history

Sampled 2025-01-21 to 2025-10-22 · 5 entry point(s) · water types: GW;SW · 18 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2025-01-21PF LIZAS (SW)SE1<4<40none
2025-01-21PZ Calzada (GW)SE1<4<40none
2025-01-22PZ Bordaleza (GW)SE1<4<40none
2025-01-22PZ Maunabo Urbano (GW)SE1n/an/an/anone
2025-01-22PZ San Pedro (GW)SE1<440none
2025-03-17PZ Maunabo Urbano (GW)SE1<4<40none
2025-04-22PF LIZAS (SW)SE2<4<40none
2025-07-22PZ Bordaleza (GW)SE2n/an/an/anone
2025-07-22PZ Calzada (GW)SE2n/an/an/anone
2025-07-23PF LIZAS (SW)SE3n/an/an/anone
2025-07-23PZ Maunabo Urbano (GW)SE2n/an/an/anone
2025-07-23PZ San Pedro (GW)SE2n/an/an/anone
2025-08-25PF LIZAS (SW)SE3<4<40none
2025-08-25PZ Bordaleza (GW)SE2<4<40none
2025-08-25PZ Calzada (GW)SE2<4<40none
2025-08-25PZ San Pedro (GW)SE2<44.80.002none
2025-08-27PZ Maunabo Urbano (GW)SE2<4<40none
2025-10-22PF LIZAS (SW)SE4<4<40none

“<4” = not detected at the reporting limit shown; “n/a” = not analyzed in that sample. Highlighted = at or above the 4 ppt MCL. HI computed per sample with non-detects as 0. Other detections lists every other quantified compound (lithium in µg/L).

All results by entry point

360 results. Each column is one sampling visit (date and UCMR 5 sample event). A number is a measured concentration; “< 4” = below the minimum reporting level shown; “–” = not analyzed in that visit. PFAS in ppt (ng/L); lithium in µg/L.

PF LIZAS facility 00001 · sample point 48150500 · surface water

CompoundMRL2025-01-21
SE1
2025-04-22
SE2
2025-07-23
SE3
2025-08-25
SE3
2025-10-22
SE4
11Cl-PF3OUdS5 ppt< 5< 5–< 5< 5
4:2 FTS3 ppt< 3< 3–< 3< 3
6:2 FTS5 ppt< 5< 5–< 5< 5
8:2 FTS5 ppt< 5< 5–< 5< 5
9Cl-PF3ONS2 ppt< 2< 2–< 2< 2
ADONA3 ppt< 3< 3–< 3< 3
HFPO-DA5 ppt< 5< 5–< 5< 5
NEtFOSAA5 ppt< 5< 5–< 5< 5
NFDHA20 ppt< 20< 20–< 20< 20
NMeFOSAA6 ppt< 6< 6–< 6< 6
PFBA5 ppt< 5< 5–< 5< 5
PFBS3 ppt< 3< 3–< 3< 3
PFDA3 ppt< 3< 3–< 3< 3
PFDoA3 ppt< 3< 3–< 3< 3
PFEESA3 ppt< 3< 3–< 3< 3
PFHpA3 ppt< 3< 3–< 3< 3
PFHpS3 ppt< 3< 3–< 3< 3
PFHxA3 ppt< 3< 3–< 3< 3
PFHxS3 ppt< 3< 3–< 3< 3
PFMBA3 ppt< 3< 3–< 3< 3
PFMPA4 ppt< 4< 4–< 4< 4
PFNA4 ppt< 4< 4–< 4< 4
PFOA4 ppt< 4< 4–< 4< 4
PFOS4 ppt< 4< 4–< 4< 4
PFPeA3 ppt< 3< 3–< 3< 3
PFPeS4 ppt< 4< 4–< 4< 4
PFTA8 ppt< 8< 8–< 8< 8
PFTrDA7 ppt< 7< 7–< 7< 7
PFUnA2 ppt< 2< 2–< 2< 2
lithium9 µg/L< 9< 9< 9–< 9

PZ Bordaleza facility 90000 · sample point 45150000 · groundwater

CompoundMRL2025-01-22
SE1
2025-07-22
SE2
2025-08-25
SE2
11Cl-PF3OUdS5 ppt< 5–< 5
4:2 FTS3 ppt< 3–< 3
6:2 FTS5 ppt< 5–< 5
8:2 FTS5 ppt< 5–< 5
9Cl-PF3ONS2 ppt< 2–< 2
ADONA3 ppt< 3–< 3
HFPO-DA5 ppt< 5–< 5
NEtFOSAA5 ppt< 5–< 5
NFDHA20 ppt< 20–< 20
NMeFOSAA6 ppt< 6–< 6
PFBA5 ppt< 5–< 5
PFBS3 ppt< 3–< 3
PFDA3 ppt< 3–< 3
PFDoA3 ppt< 3–< 3
PFEESA3 ppt< 3–< 3
PFHpA3 ppt< 3–< 3
PFHpS3 ppt< 3–< 3
PFHxA3 ppt< 3–< 3
PFHxS3 ppt< 3–< 3
PFMBA3 ppt< 3–< 3
PFMPA4 ppt< 4–< 4
PFNA4 ppt< 4–< 4
PFOA4 ppt< 4–< 4
PFOS4 ppt< 4–< 4
PFPeA3 ppt< 3–< 3
PFPeS4 ppt< 4–< 4
PFTA8 ppt< 8–< 8
PFTrDA7 ppt< 7–< 7
PFUnA2 ppt< 2–< 2
lithium9 µg/L< 9< 9–

PZ Calzada facility 90100 · sample point 45150100 · groundwater

CompoundMRL2025-01-21
SE1
2025-07-22
SE2
2025-08-25
SE2
11Cl-PF3OUdS5 ppt< 5–< 5
4:2 FTS3 ppt< 3–< 3
6:2 FTS5 ppt< 5–< 5
8:2 FTS5 ppt< 5–< 5
9Cl-PF3ONS2 ppt< 2–< 2
ADONA3 ppt< 3–< 3
HFPO-DA5 ppt< 5–< 5
NEtFOSAA5 ppt< 5–< 5
NFDHA20 ppt< 20–< 20
NMeFOSAA6 ppt< 6–< 6
PFBA5 ppt< 5–< 5
PFBS3 ppt< 3–< 3
PFDA3 ppt< 3–< 3
PFDoA3 ppt< 3–< 3
PFEESA3 ppt< 3–< 3
PFHpA3 ppt< 3–< 3
PFHpS3 ppt< 3–< 3
PFHxA3 ppt< 3–< 3
PFHxS3 ppt< 3–< 3
PFMBA3 ppt< 3–< 3
PFMPA4 ppt< 4–< 4
PFNA4 ppt< 4–< 4
PFOA4 ppt< 4–< 4
PFOS4 ppt< 4–< 4
PFPeA3 ppt< 3–< 3
PFPeS4 ppt< 4–< 4
PFTA8 ppt< 8–< 8
PFTrDA7 ppt< 7–< 7
PFUnA2 ppt< 2–< 2
lithium9 µg/L< 9< 9–

PZ Maunabo Urbano facility 90400 · sample point 45154000 · groundwater

CompoundMRL2025-01-22
SE1
2025-03-17
SE1
2025-07-23
SE2
2025-08-27
SE2
11Cl-PF3OUdS5 ppt–< 5–< 5
4:2 FTS3 ppt–< 3–< 3
6:2 FTS5 ppt–< 5–< 5
8:2 FTS5 ppt–< 5–< 5
9Cl-PF3ONS2 ppt–< 2–< 2
ADONA3 ppt–< 3–< 3
HFPO-DA5 ppt–< 5–< 5
NEtFOSAA5 ppt< 5––< 5
NFDHA20 ppt–< 20–< 20
NMeFOSAA6 ppt< 6––< 6
PFBA5 ppt–< 5–< 5
PFBS3 ppt–< 3–< 3
PFDA3 ppt–< 3–< 3
PFDoA3 ppt–< 3–< 3
PFEESA3 ppt–< 3–< 3
PFHpA3 ppt–< 3–< 3
PFHpS3 ppt–< 3–< 3
PFHxA3 ppt–< 3–< 3
PFHxS3 ppt–< 3–< 3
PFMBA3 ppt–< 3–< 3
PFMPA4 ppt–< 4–< 4
PFNA4 ppt–< 4–< 4
PFOA4 ppt–< 4–< 4
PFOS4 ppt–< 4–< 4
PFPeA3 ppt–< 3–< 3
PFPeS4 ppt–< 4–< 4
PFTA8 ppt< 8––< 8
PFTrDA7 ppt< 7––< 7
PFUnA2 ppt–< 2–< 2
lithium9 µg/L< 9–< 9–

PZ San Pedro facility 90200 · sample point 45150200 · groundwater

CompoundMRL2025-01-22
SE1
2025-07-23
SE2
2025-08-25
SE2
PFBS3 ppt< 3–3.2
PFOS4 ppt4–4.8
11Cl-PF3OUdS5 ppt< 5–< 5
4:2 FTS3 ppt< 3–< 3
6:2 FTS5 ppt< 5–< 5
8:2 FTS5 ppt< 5–< 5
9Cl-PF3ONS2 ppt< 2–< 2
ADONA3 ppt< 3–< 3
HFPO-DA5 ppt< 5–< 5
NEtFOSAA5 ppt< 5–< 5
NFDHA20 ppt< 20–< 20
NMeFOSAA6 ppt< 6–< 6
PFBA5 ppt< 5–< 5
PFDA3 ppt< 3–< 3
PFDoA3 ppt< 3–< 3
PFEESA3 ppt< 3–< 3
PFHpA3 ppt< 3–< 3
PFHpS3 ppt< 3–< 3
PFHxA3 ppt< 3–< 3
PFHxS3 ppt< 3–< 3
PFMBA3 ppt< 3–< 3
PFMPA4 ppt< 4–< 4
PFNA4 ppt< 4–< 4
PFOA4 ppt< 4–< 4
PFPeA3 ppt< 3–< 3
PFPeS4 ppt< 4–< 4
PFTA8 ppt< 8–< 8
PFTrDA7 ppt< 7–< 7
PFUnA2 ppt< 2–< 2
lithium9 µg/L< 9< 9–

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
PFOS1217%4.8
2025-08-25
0.73–4.07<MRL<MRL44.8
PFBS128%3.2
2025-08-25
0.27–3.02<MRL<MRL<MRL3.2

Never detected (28): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFBA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFHxA, PFHxS, PFMBA, PFMPA, PFNA, PFOA, PFPeA, PFPeS, PFTA, PFTrDA, PFUnA, lithium.

Left-censored Kaplan–Meier statistics (Helsel 2005; Helsel & Lee 2006, NADA for R). Units: ppt; lithium µg/L. Each compound has one reporting limit, so the Kaplan–Meier mean equals the upper mean bound (non-detects at the MRL); the lower bound sets non-detects to 0. “<MRL” = the percentile falls below the reporting limit and cannot be estimated. These describe this system's UCMR 5 samples, not population estimates.

Sources

  • EPA UCMR 5 occurrence data text files (UCMR5_All.txt; samples 2023-01-10 to 2026-01-12; data summary dated Jul 2026)
  • EPA SDWIS via ECHO SDWA downloads, quarter 2026Q3
  • EPA Public Water System Service Areas v3 (Mar 2026)
  • US Census Bureau cartographic boundary counties 1:500k, 2024
  • EPA/USGS NHDPlus V2 (medium resolution) flowlines, Strahler order 2+

Data build 9c1cfa699a74 · 2026-10-18T04:05Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.