Public water system · AZ0403015
ActiveMountain Dell Water Inc.
At a glance
Mountain Dell Water Inc. (PWSID AZ0403015) is an active community water system in Coconino County, Arizona. It reports serving 250 people through 86 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
250
Service connections
86
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mountain Dell Water Inc. compare with other water systems in Coconino County?
By EPA's size categories, Mountain Dell Water Inc. is a very small system (500 people or fewer). Coconino County has 114 active public water systems. Its population served is well below the county average of 1,573 people per system, and accounts for 0.1% of the 179,316 people reported by systems filed under the county. Across Arizona, the 1,769 active systems average 4,369 people each. Nationally, the average active community water system reports serving 6,703 people, so Mountain Dell Water Inc. is well below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Arizona has 936 active community water systems, 53% of the state's 1,769 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,612 Arizona systems (91%) list groundwater as their primary source.
Who owns and regulates Mountain Dell Water Inc.?
EPA lists Mountain Dell Water Inc. as privately owned. The AZ state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 36 of the 114 active systems in Coconino County (32%) are also privately owned.
Does Mountain Dell Water Inc. have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. The violations listed here began between July 2015 and July 2025. By type: 8 public notice, recordkeeping or other, 2 monitoring, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Consumer Confidence Rule (7 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-12-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-05-19 | Required treatment not metFailure To Address Deficiency · code 45 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2024-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-10-02 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2023-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2019-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2018-05-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2016-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2016-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2015-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Mountain Dell Water Inc.: frequently asked questions
Who runs Mountain Dell Water Inc.?
Mountain Dell Water Inc. (PWSID AZ0403015) is a community water system privately owned. It is regulated by the AZ state drinking water program.
How many people does Mountain Dell Water Inc. serve?
Mountain Dell Water Inc. reports serving 250 people through 86 service connections in Coconino County, Arizona.
Where does Mountain Dell Water Inc. get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Mountain Dell Water Inc. have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Mountain Dell Water Inc.'s water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the AZ state drinking water program.
Where can I find Mountain Dell Water Inc.'s water quality report?
As a community water system, Mountain Dell Water Inc. must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Coconino County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Flagstaff City of | Coconino | 79,796 | Community | Surface water |
| Grand Canyon National Park | Coconino | 16,590 | Community | Groundwater |
| Arizona Water Co - Sedona | Coconino | 12,104 | Community | Groundwater |
| Doney Park Water | Coconino | 8,996 | Community | Groundwater |
| Arizona Water Co - Pinewood | Coconino | 8,089 | Community | Groundwater |
| Page City of | Coconino | 7,420 | Community | Surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Mountain Dell Water Inc., PWSID AZ0403015, Arizona”, https://aquacensus.com/water-systems/arizona/mountain-dell-water-inc-az0403015 (data as of October 1, 2026).