Parker Wsd

PFAS monitoring results for a public water system in Colorado

CO0118040UCMR 5EPA monitoring data
4.8Highest PFOA result, ppt
<MRLHighest PFOS result, ppt
0.002Highest Hazard Index
780Results
PWSID
CO0118040
State
Colorado
System type
community water system (CWS)
Population served
75,949
City
Parker
Counties
Douglas County
Primary source water
surface water
UCMR 5 sampling
2024-04-01 to 2025-07-01 · 11 entry point(s) · water types: GW;SW
Service-area boundary
authoritative

PFOA 1–3 × its limit highest single result
PFOA 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

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)4.81.24
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).

Compared with Colorado standards

Highest single resultWorst entry-point average*Colorado
PFOA (ppt)4.81.24
PFOS (ppt)004
PFNA (ppt)0010
PFHxS (ppt)0010
HFPO-DA (GenX) (ppt)0010

Sum standards add the listed compounds within each sample (non-detects = 0). State compliance is normally judged on averages over time; these are screening comparisons.

Sampling history

Sampled 2024-04-01 to 2025-07-01 · 11 entry point(s) · water types: GW;SW · 29 sampling visits. PFAS in ppt (ng/L).

DateEntry pointEventPFOAPFOSHIOther detections
2024-04-01REUTER-HESS GWTP (GW)SE1<4<40lithium 25 µg/L
2024-09-04CANYONS WELL HOUSE TREATMENT PLANT (GW)SE1n/an/an/alithium 21.4 µg/L
2024-09-04PARKER RIDGE WTP (GW)SE1<4<40lithium 17.2 µg/L
2024-09-04ROWLEY DOWNS WTP (GW)SE1n/an/an/alithium 20.3 µg/L
2024-09-18RIDGEGATE WELL HOUSE TREATMENT PLANT (GW)SE1<4<40none
2024-09-26CANYONS WELL HOUSE TREATMENT PLANT (GW)SE1<4<40none
2024-09-26RIDGEGATE WELL HOUSE TREATMENT PLANT (GW)SE1n/an/an/alithium 18 µg/L
2024-09-26ROWLEY DOWNS WTP (GW)SE1<4<40none
2024-09-30CLARK FARMS WTP (GW)SE1<4<40lithium 14.7 µg/L
2024-10-02EP - WISE AND CHLORAMINATION (SW)SE1<4<40PFHxA 3.3, PFPeA 4, lithium 27.6 µg/L
2024-10-02PARKER NORTH WTP (GW)SE1<4<40lithium 14.1 µg/L
2024-10-02REATA NORTH WTP (GW)SE1<4<40lithium 23 µg/L
2024-10-02REGIONAL WTP (GW)SE1<4<40lithium 22.7 µg/L
2024-10-02REUTER-HESS GWTP (GW)SE2<4<40lithium 26.1 µg/L
2024-10-02RUETER-HESS SWTP (SW)SE1<4<40.002PFBA 8.6, PFHxA 10.9, PFPeA 13.5, lithium 25.1 µg/L
2025-01-22EP - WISE AND CHLORAMINATION (SW)SE2<4<40PFHxA 5.8, PFPeA 7.4, lithium 19.1 µg/L
2025-01-22RUETER-HESS SWTP (SW)SE2<4<40.002PFBA 7.8, PFHxA 10.3, PFPeA 12.9, lithium 22.8 µg/L
2025-03-10RIDGEGATE WELL HOUSE TREATMENT PLANT (GW)SE2<4<40lithium 16.2 µg/L
2025-03-12ROWLEY DOWNS WTP (GW)SE2<4<40lithium 19 µg/L
2025-03-19PARKER RIDGE WTP (GW)SE2<4<40lithium 17.6 µg/L
2025-03-25CLARK FARMS WTP (GW)SE2<4<40lithium 16.1 µg/L
2025-04-02EP - WISE AND CHLORAMINATION (SW)SE34.5<40.002PFBA 7.9, PFHxA 11, PFPeA 12.9, lithium 23 µg/L
2025-04-02REGIONAL WTP (GW)SE2<4<40lithium 23.3 µg/L
2025-04-02RUETER-HESS SWTP (SW)SE34.8<40.002PFBA 7.6, PFHxA 11.9, PFPeA 14, lithium 23.1 µg/L
2025-04-15CANYONS WELL HOUSE TREATMENT PLANT (GW)SE2<4<40lithium 20.1 µg/L
2025-04-15PARKER NORTH WTP (GW)SE2<4<40lithium 14 µg/L
2025-04-23REATA NORTH WTP (GW)SE2<4<40lithium 24.2 µg/L
2025-07-01EP - WISE AND CHLORAMINATION (SW)SE4<4<40PFHxA 5.1, PFPeA 6.7, lithium 21.3 µg/L
2025-07-01RUETER-HESS SWTP (SW)SE4<4<40.002PFBA 7.6, PFHxA 8.9, PFPeA 12.4, lithium 23.9 µg/L

“<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

780 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.

CANYONS WELL HOUSE TREATMENT PLANT facility 084 · sample point 084 · groundwater

CompoundMRL2024-09-04
SE1
2024-09-26
SE1
2025-04-15
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/L21.4–20.1

CLARK FARMS WTP facility 017 · sample point 017 · groundwater

CompoundMRL2024-09-30
SE1
2025-03-25
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/L14.716.1

EP - WISE AND CHLORAMINATION facility 082 · sample point 082 · surface water

CompoundMRL2024-10-02
SE1
2025-01-22
SE2
2025-04-02
SE3
2025-07-01
SE4
PFBA5 ppt< 5< 57.9< 5
PFBS3 ppt< 3< 34.3< 3
PFHxA3 ppt3.35.8115.1
PFOA4 ppt< 4< 44.5< 4
PFPeA3 ppt47.412.96.7
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
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
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/L27.619.12321.3

PARKER NORTH WTP facility 030 · sample point 030 · groundwater

CompoundMRL2024-10-02
SE1
2025-04-15
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/L14.114

PARKER RIDGE WTP facility 042 · sample point 042 · groundwater

CompoundMRL2024-09-04
SE1
2025-03-19
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/L17.217.6

REATA NORTH WTP facility 060 · sample point 060 · groundwater

CompoundMRL2024-10-02
SE1
2025-04-23
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/L2324.2

REGIONAL WTP facility 071 · sample point 071 · groundwater

CompoundMRL2024-10-02
SE1
2025-04-02
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/L22.723.3

REUTER-HESS GWTP facility 080 · sample point 080 · groundwater

CompoundMRL2024-04-01
SE1
2024-10-02
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/L2526.1

RIDGEGATE WELL HOUSE TREATMENT PLANT facility 085 · sample point 085 · groundwater

CompoundMRL2024-09-18
SE1
2024-09-26
SE1
2025-03-10
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–1816.2

ROWLEY DOWNS WTP facility 005T · sample point 005T · groundwater

CompoundMRL2024-09-04
SE1
2024-09-26
SE1
2025-03-12
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/L20.3–19

RUETER-HESS SWTP facility 078 · sample point 078 · surface water

CompoundMRL2024-10-02
SE1
2025-01-22
SE2
2025-04-02
SE3
2025-07-01
SE4
PFBA5 ppt8.67.87.67.6
PFBS3 ppt4.23.44.63.1
PFHxA3 ppt10.910.311.98.9
PFOA4 ppt< 4< 44.8< 4
PFPeA3 ppt13.512.91412.4
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
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
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/L25.122.823.123.9

Statistics by compound

CompoundResultsDetectedHighest (date)Mean boundsKM medianP75P90P95
lithium26100%27.6
2024-10-02
20.73–20.7321.323.325.126.1
PFHxA2631%11.9
2025-04-02
2.58–4.66<MRL5.110.911
PFPeA2631%14
2025-04-02
3.22–5.3<MRL6.712.913.5
PFBA2619%8.6
2024-10-02
1.52–5.56<MRL<MRL7.87.9
PFBS2619%4.6
2025-04-02
0.75–3.18<MRL<MRL4.24.3
PFOA268%4.8
2025-04-02
0.36–4.05<MRL<MRL<MRL4.5

Never detected (24): 11Cl-PF3OUdS, 4:2 FTS, 6:2 FTS, 8:2 FTS, 9Cl-PF3ONS, ADONA, HFPO-DA, NEtFOSAA, NFDHA, NMeFOSAA, PFDA, PFDoA, PFEESA, PFHpA, PFHpS, PFHxS, PFMBA, PFMPA, PFNA, 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 2023-01-03 to 2026-05-07; 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 e835c17dd18b · 2026-10-18T04:06Z · UCMR 5 release Jul2026 · SDWIS 2026Q3. Data and methods.