No health-based violations on EPA record since 2016.
Serves about 11,514 people (3,838 connections) with groundwater from its own wells, and buys water from Cimarron MUD, Ponderosa Forest Utility District, Mason Creek Utility District and 1 more.
From EPA's record for TX1010581. PurityMap is independent of Harris County MUD 81.
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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 September 2024 to March 2025.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Lithium | 31.9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Above the referenced health-based guidance value | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| 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 | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-09-20 to 2025-03-07 | UCMR5 Analytical Results: HARRIS COUNTY MUD 81 (TX1010581) |
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 →Harris County MUD 81's phone number on EPA record is 713-860-6400. Its mailing address is 3200 SOUTHWEST FWY STE 2600, ALLEN BOONE HUMPRHIES ROBINSON LLP, HOUSTON, TX 77027-7537.
According to EPA's record, Harris County MUD 81 uses groundwater from its own wells, and buys water from Cimarron MUD, Ponderosa Forest Utility District, Mason Creek Utility District and 1 more.
No health-based violations on EPA record since 2016. EPA also lists 13 missed or late tests or reports in 10 years. The record comes from EPA's SDWIS compliance database.
Lead was not detected at the 90th percentile of tap samples in Harris County MUD 81's latest lead and copper round, which ended in December 2025. The federal action level is 15 µg/L.
PurityMap has no verified website for Harris County MUD 81. Its phone number on EPA record is 713-860-6400. Its mailing address on EPA record is 3200 SOUTHWEST FWY STE 2600, ALLEN BOONE HUMPRHIES ROBINSON LLP, HOUSTON, TX 77027-7537. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.