Public water system · AZ0412029
ActiveSonoita Mercantile Water System
At a glance
Sonoita Mercantile Water System (PWSID AZ0412029) is an active transient non-community water system in Santa Cruz County, Arizona. It reports serving 125 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as under public/private ownership. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
125
Service connections
2
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Sonoita Mercantile Water System compare with other water systems in Santa Cruz County?
By EPA's size categories, Sonoita Mercantile Water System is a very small system (500 people or fewer). Santa Cruz County has 37 active public water systems. Its population served is well below the county average of 1,350 people per system, and accounts for 0.3% of the 49,946 people reported by systems filed under the county. Across Arizona, the 1,769 active systems average 4,369 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Sonoita Mercantile Water System is about 13% below that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Arizona has 601 active transient non-community water systems, 34% 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 Sonoita Mercantile Water System?
EPA lists Sonoita Mercantile Water System as under public/private ownership. 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. 13 of the 37 active systems in Santa Cruz County (35%) are also under public/private ownership.
Does Sonoita Mercantile Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in January 2026. The violations listed here began between April 2023 and January 2026. By type: 4 monitoring and reporting, 3 public notice, recordkeeping or other, 3 contaminant level above the legal limit, 1 monitoring and 1 reporting. The contaminant or rule involved most often is Nitrate (7 of them). EPA lists 10 as resolved and 2 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 2026-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2024-11-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-08-24 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-07-19 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2024-04-14 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2024-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2024-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2023-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2023-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | 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.
Sonoita Mercantile Water System: frequently asked questions
Who runs Sonoita Mercantile Water System?
Sonoita Mercantile Water System (PWSID AZ0412029) is a transient non-community water system under public/private ownership. It is regulated by the AZ state drinking water program.
How many people does Sonoita Mercantile Water System serve?
Sonoita Mercantile Water System reports serving 125 people through 2 service connections in Santa Cruz County, Arizona.
Where does Sonoita Mercantile Water System 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 Sonoita Mercantile Water System have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in January 2026. 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 Sonoita Mercantile Water System'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, 3 are health-based, and the most recent began in January 2026. For current results, consult EPA ECHO, or the AZ state drinking water program.
Where can I find Sonoita Mercantile Water System's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Sonoita Mercantile Water System is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Santa Cruz County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Nogales City of | Santa Cruz | 22,000 | Community | Groundwater |
| Liberty Water Rio Rico | Santa Cruz | 17,960 | Community | Groundwater |
| Valle Verde Water Company - East | Santa Cruz | 2,331 | Community | Groundwater |
| Epcor - Tubac | Santa Cruz | 2,076 | Community | Groundwater |
| Baca Float Water Company | Santa Cruz | 1,090 | Community | Groundwater |
| Patagonia Water Department | Santa Cruz | 819 | Community | Groundwater |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Sonoita Mercantile Water System, PWSID AZ0412029, Arizona”, https://aquacensus.com/water-systems/arizona/sonoita-mercantile-water-system-az0412029 (data as of October 1, 2026).