No open EPA violations as of 2026-10-15.
EPA record checked 2026-10-06
From EPA's record for CO0118010. PurityMap is independent of Town of Castle Rock.
Every community water system publishes one each year. Your water bill or the utility's website links to it.
As listed in EPA's records. Your water bill names your supplier.
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31 results are on record. These 5 come first: results above a listed reference, then those closest to a legal limit.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Lithium | 25 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Lead (90th percentile) | 2 µg/L | 15 µg/L federal action level | Below the listed reference | 2026–2026 monitoring period (still open) | Lead & Copper Rule 90th-percentile: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorobutanoic acid (PFBA) | 5.1 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoropentanoic acid (PFPeA) | 4.7 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-08-07 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-08-07 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| 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 | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-08-07 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-08-07 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-05-25 to 2024-02-21 | UCMR5 Analytical Results: CASTLE ROCK TOWN OF (CO0118010) |
0health-based violations in the last 10 years · none open as of 2026-10-15
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit. Meeting a federal limit is a compliance fact, not a health clearance.
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.
Tested your own tap? Read your results →
Local help
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
One email when a new sampling round is published or a result moves across its reference.
Follow this water →Its phone number on EPA record is 720-733-6041 and its mailing address is 175 KELLOGG CT, CASTLE ROCK, CO 80109. These details come from the system's EPA record.
PurityMap has no verified website for Town of Castle Rock. Its mailing address on EPA record is 175 KELLOGG CT, CASTLE ROCK, CO 80109. Your water bill lists the ways to pay. PurityMap does not take payments.
EPA's records list Town of Castle Rock as serving Castle Rock, Colorado. Your water bill names your supplier.
PurityMap's record for Town of Castle Rock holds results for 29 PFAS substances. 2 were detected, and none is above a federal legal limit. Each result links to its source in the city report.
No open EPA violations as of 2026-10-15: that is what EPA's record shows for Town of Castle Rock. The record comes from EPA's SDWIS compliance database.
Town of Castle Rock is on EPA record as drawing from surface water.
Start with the hot-or-cold tap check. Where Town of Castle Rock reported something related, it's shown below.
Lead at Town of Castle Rock: 2 µg/L (90th percentile, 2026 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.