City Of Richwood

PFAS monitoring results for a public water system in Texas

TX0200035UCMR 5EPA monitoring data
<MRLHighest PFOA result, ppt
<MRLHighest PFOS result, ppt
0.002Highest Hazard Index
360Results
PWSID
TX0200035
State
Texas
System type
community water system (CWS)
Population served
7,605
City
Richwood
Counties
Brazoria County
Primary source water
surface water (purchased)
UCMR 5 sampling
2023-02-21 to 2023-11-28 · 3 entry point(s) · water types: SW
Service-area boundary
authoritative

Hazard Index below its limit highest single result
Hazard Index below 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.

Water purchased from

  • Brazosport Water Authority (TX0200497)
    Seller not monitored under UCMR 5.
  • City Of Clute (TX0200004)
    Seller's highest results: PFOA <MRL · PFOS <MRL · HI 0.382 · detected: NFDHA;PFBA;PFBS;PFHxA;PFHxS;PFPeA

Seller results are the seller's own entry-point samples, not measurements of this system's water. This system's own samples (below) may reflect purchased water, its own sources, or both.

Compared with EPA's 2024 values

Highest single resultWorst entry-point average*Limit
PFOA (ppt)<MRL04
PFOS (ppt)<MRL04
Hazard Index0.0020.0021.0†

“<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 Texas PFAS drinking-water standard in effect or proposed as of 2026-10-17: No state PFAS drinking-water standard; TCEQ implementing federal NPDWR (BCLP state survey, Jan 2026).

Sampling history

Sampled 2023-02-21 to 2023-11-28 · 3 entry point(s) · water types: SW · 16 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2023-02-21CITY OF RICHWOOD (SW)SE1n/an/an/anone
2023-02-21CITY OF RICHWOOD (SW)SE1n/an/an/alithium 34 µg/L
2023-02-21CITY OF RICHWOOD (SW)SE1n/an/an/alithium 33.9 µg/L
2023-05-02CITY OF RICHWOOD (SW)SE2<4<40.002NFDHA 31.3, PFBA 7.5, PFHxA 4.8, PFPeA 69.9, lithium 9.85 µg/L
2023-05-02CITY OF RICHWOOD (SW)SE2<4<40lithium 31.9 µg/L
2023-05-02CITY OF RICHWOOD (SW)SE2<4<40lithium 31.8 µg/L
2023-05-24CITY OF RICHWOOD (SW)SE1<4<40none
2023-05-24CITY OF RICHWOOD (SW)SE1<4<40none
2023-05-24CITY OF RICHWOOD (SW)SE1<4<40none
2023-08-28CITY OF RICHWOOD (SW)SE3<4<40lithium 42 µg/L
2023-08-28CITY OF RICHWOOD (SW)SE3<4<40lithium 44 µg/L
2023-08-28CITY OF RICHWOOD (SW)SE3n/an/an/alithium 13 µg/L
2023-11-14CITY OF RICHWOOD (SW)SE4<4<40.0026:2 FTS 5.8, PFBA 9.9, PFHxA 5.7, PFPeA 154, lithium 13.6 µg/L
2023-11-14CITY OF RICHWOOD (SW)SE4<4<40lithium 35.6 µg/L
2023-11-14CITY OF RICHWOOD (SW)SE4<4<406:2 FTS 5.3, lithium 36.2 µg/L
2023-11-28CITY OF RICHWOOD (SW)SE3<4<40.002PFBA 38, PFHxA 5.4, PFPeA 180

“<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.

CITY OF RICHWOOD facility EP002 · sample point TRTTAP · surface water

CompoundMRL2023-02-21
SE1
2023-05-02
SE2
2023-05-24
SE1
2023-08-28
SE3
2023-11-14
SE4
2023-11-28
SE3
6:2 FTS5 ppt–< 5< 5–5.8< 5
NFDHA20 ppt–31.3< 20–< 20< 20
PFBA5 ppt–7.5< 5–9.938
PFBS3 ppt–3.4< 3–4.54
PFHxA3 ppt–4.8< 3–5.75.4
PFPeA3 ppt–69.9< 3–154180
11Cl-PF3OUdS5 ppt–< 5< 5–< 5< 5
4:2 FTS3 ppt–< 3< 3–< 3< 3
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–
NMeFOSAA6 ppt< 6< 6–< 6< 6–
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
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
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< 99.85–1313.6–

CITY OF RICHWOOD facility EP003 · sample point TRTTAP · surface water

CompoundMRL2023-02-21
SE1
2023-05-02
SE2
2023-05-24
SE1
2023-08-28
SE3
2023-11-14
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/L3431.9–4235.6

CITY OF RICHWOOD facility EP004 · sample point TRTTAP · surface water

CompoundMRL2023-02-21
SE1
2023-05-02
SE2
2023-05-24
SE1
2023-08-28
SE3
2023-11-14
SE4
6:2 FTS5 ppt–< 5< 5< 55.3
11Cl-PF3OUdS5 ppt–< 5< 5< 5< 5
4:2 FTS3 ppt–< 3< 3< 3< 3
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/L33.931.8–4436.2

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium1292%44
2023-08-28
27.15–27.931.935.64244
PFBA1225%38
2023-11-28
4.62–8.37<MRL<MRL9.938
PFBS1225%4.5
2023-11-14
0.99–3.24<MRL<MRL44.5
PFHxA1225%5.7
2023-11-14
1.32–3.58<MRL<MRL5.45.7
PFPeA1225%180
2023-11-28
33.66–35.91<MRL<MRL154180
6:2 FTS1217%5.8
2023-11-14
0.93–5.09<MRL<MRL5.35.8
NFDHA128%31.3
2023-05-02
2.61–20.94<MRL<MRL<MRL31.3

Never detected (23): 11Cl-PF3OUdS, 4:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFHxS, PFMBA, PFMPA, PFNA, PFOA, PFOS, PFPeS, PFTA, PFTrDA, PFUnA.

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 2023-01-09 to 2026-06-16; 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 a6f3d99247ed · 2026-10-18T04:13Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.