Hydrohistorian
Arapahoe County Water & Wastewater Authority
Serves Foxfield, Dove Valley, Centennial.
Boundary traced from IRE. About 30 km².
Where the water comes from
| Facility | Kind | Water |
|---|---|---|
| DENMARK ARAPAHOE | Well | Groundwater |
| AIRPORT 3 | Well | Groundwater |
| A2 | Well | Groundwater |
| A1 | Well | Groundwater |
| PURCHASED FROM JWPP CO0103418 | Consecutive connection (purchased) | Groundwater · from JOINT WATER PURIFICATION PLANT |
| CA2 | Well | Groundwater |
| CD2R | Well | Groundwater |
| PURCHASED WATER FROM CO0103040 | Consecutive connection (purchased) | Groundwater · from EAST VALLEY MD |
| PURCHASED WATER FROM CO0118020 | Consecutive connection (purchased) | Groundwater · from COTTONWOOD WSD |
| PURCHASED WATER FROM CO0103035 | Consecutive connection (purchased) | Groundwater · from EAST CHERRY CREEK VALLEY WSD |
These are EPA's facility records, not DWR structures. Which decreed rights sit behind an intake is the next phase; nothing here is inferred.
Wholesale connections
Buys water from JOINT WATER PURIFICATION PLANT, EAST VALLEY MD, COTTONWOOD WSD, EAST CHERRY CREEK VALLEY WSD.
DWR structures that name this system
Source Probable join · fetched 2026-09-09 · matched on DWR's recorded contact or an EPA intake name; verify on the dossier
No DWR structure on file records this system as its contact, and none of its EPA intakes matches a structure name in its districts. DWR records a contact on only a fraction of structures, and only for districts fetched from its live service, so this is absence of a record, not evidence of no rights.
Compliance record
Source Register of another agency · fetched 2026-09-09 · verify at EPA ECHO ↗
No open violation and no health-based violation on EPA's federal record for this system at the last monthly fetch. That is a record of reported compliance, not a test result: SDWIS carries violations, not routine sample values.
EPA's own summary: violations in 0 of the last 12 quarters.
No health-based or open violation on the federal record for this system.
What the regulator did about it
21 enforcement actions on this system's federal record. In Colorado the state is the primacy agency, so most actions are the state's; EPA acts directly on tribal systems and when it steps in.
| Date | Action | By |
|---|---|---|
| 2020-10-29 | St Compliance achieved System sampled SOCA at 006T in April 2020. |
state |
| 2020-10-29 | St Compliance achieved System sampled SOCA at 007T in April 2020. |
state |
| 2020-10-29 | St Compliance achieved System sampled SOCA at 016T in April 2020. |
state |
| 2020-10-29 | St Compliance achieved System sampled SOCA at 019T in April 2020. |
state |
| 2020-10-29 | St Compliance achieved System sampled SOCA at 022 in April 2020. |
state |
| 2020-10-29 | St Compliance achieved System sampled SOCA at 032 in April 2020. |
state |
| 2020-04-02 | St Compliance achieved Returning to compliance after conversation with Jacob Bakes (lead operator) on 4/2/20 providing evidence of circulation of 2018 CCR in May of 2019; therefore, SOX'ing to compliance and allowing system to remove violation for 2019 CCR; jlm 4/2/2020. |
state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2020-02-07 | St Violation/Reminder Notice | state |
| 2020-02-07 | St Public Notif requested | state |
| 2019-11-07 | St Violation/Reminder Notice | state |
20 most recent of 21; the rest are on the ECHO report.
Lead and copper
The latest 90th-percentile lead result is 0.0011 mg/L (sampling period ending 2025-12-31) against an action level of 0.015 mg/L, below it. 11 results on file.
The action level is not a health limit: it is the level at which the rule requires a system to act (corrosion control, public education, and in some cases replacing lead service lines). Lead mostly enters water from household plumbing, so a system-wide percentile does not tell you what comes out of one tap.
Violation, enforcement and lead/copper records are EPA SDWIS federal reporting, fetched monthly; the summary is EPA ECHO. Code names come from EPA's own REF_CODE_VALUE table. SDWIS carries violations, not routine sample results — nitrate, disinfection by-product and PFAS values are not in it, and a clean record here means nothing was reported as a violation, not that nothing was ever detected. For what was measured, ask the system for its Consumer Confidence Report.
PFAS and lithium: EPA's UCMR 5 monitoring, 2023–2025
Source Register of another agency · fetched 2026-09-09 · verify at EPA UCMR occurrence data ↗
16 samples, 420 results, 2023-02-08 to 2024-01-10. 5 of the 29 PFAS were detected at least once; lithium was measured up to 23.2 µg/L (no federal limit). PFOA measured up to 0.0046 µg/L, at or above EPA's 2024 limit of 0.004 µg/L.
| Contaminant | Results | Detected | Highest, µg/L | Reporting limit |
|---|---|---|---|---|
| HFPO-DA | 14 | 0 | < 0.005 | 0.005 |
| PFBA | 14 | 1 | 0.0055 | 0.005 |
| PFBS | 14 | 2 | 0.0061 | 0.003 |
| PFHxA | 14 | 2 | 0.0068 | 0.003 |
| PFHxS | 14 | 0 | < 0.003 | 0.003 |
| PFNA | 14 | 0 | < 0.004 | 0.004 |
| PFOA | 14 | 1 | 0.0046 (≥ 0.004 MCL) | 0.004 |
| PFOS | 14 | 0 | < 0.004 | 0.004 |
| PFPeA | 14 | 2 | 0.0079 | 0.003 |
| lithium | 14 | 14 | 23.2 | 9.0 |
Rows shown: every detected contaminant plus the regulated PFAS and lithium; the rest were below their reporting limits. These are UCMR monitoring samples, not compliance samples. EPA's April 2024 rule set 4.0 ng/L (0.004 µg/L) for PFOA and PFOS, the same as UCMR 5's reporting limit, so any detection of either is at or above it; the rule's compliance date and its other limits have been under revision since 2025 and are not applied here. State PFAS sampling is on CDPHE's pages ↗.
Common questions
Who provides drinking water in Centennial, Colorado?
Arapahoe County Water & Wastewater Authority is the public water system serving 31,000 people in Arapahoe County, from groundwater. Its EPA public water system id is CO0203002.
Where does Arapahoe County Water & Wastewater Authority get its water?
Arapahoe County Water & Wastewater Authority reports groundwater as its primary source. EPA lists its source facilities as DENMARK ARAPAHOE, AIRPORT 3, A2, A1.
Does Arapahoe County Water & Wastewater Authority have any drinking water violations?
EPA's compliance record shows no open health-based violations for Arapahoe County Water & Wastewater Authority at the last monthly fetch. Older and non-health-based entries, if any, are listed on this page.
Places this system serves
Census places its EPA service-area boundary substantially covers. Each page lists every system serving that place.
Every provider in Arapahoe County.
The record
EPA SDWIS federal reporting as of 2026-09-08; the compliance record above is EPA's own, fetched monthly, and the ECHO report carries the rest. Report a problem →