Public water system · CA5500060
ActiveMi Wuk Heights Mwc
At a glance
Mi Wuk Heights Mwc (PWSID CA5500060) is an active community water system in Tuolumne County, California. It reports serving 445 people through 159 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2004.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
445
Service connections
159
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mi Wuk Heights Mwc compare with other water systems in Tuolumne County?
By EPA's size categories, Mi Wuk Heights Mwc is a very small system (500 people or fewer). Tuolumne County has 117 active public water systems. Its population served is about 37% below the county average of 706 people per system, and accounts for 0.5% of the 82,611 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so Mi Wuk Heights Mwc 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. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates Mi Wuk Heights Mwc?
EPA lists Mi Wuk Heights Mwc as privately owned. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 75 of the 117 active systems in Tuolumne County (64%) are also privately owned.
Does Mi Wuk Heights Mwc have drinking water violations?
EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2004. The violations listed here began between October 1980 and October 2004. By type: 4 monitoring and reporting, 3 contaminant level above the legal limit and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 5 as resolved and 4 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 |
|---|---|---|---|---|
| 2004-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1999-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1998-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1983-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1982-10-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1980-10-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 9 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.
Mi Wuk Heights Mwc: frequently asked questions
Who runs Mi Wuk Heights Mwc?
Mi Wuk Heights Mwc (PWSID CA5500060) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Mi Wuk Heights Mwc serve?
Mi Wuk Heights Mwc reports serving 445 people through 159 service connections in Tuolumne County, California.
Where does Mi Wuk Heights Mwc 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 Mi Wuk Heights Mwc have any drinking water violations?
EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2004. 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 Mi Wuk Heights Mwc'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. EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in October 2004. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Mi Wuk Heights Mwc's water quality report?
As a community water system, Mi Wuk Heights Mwc 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 Tuolumne County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Tud - Upper Basin Water System | Tuolumne | 13,280 | Community | Surface water |
| Tud - Sonora/Jamestown Water System | Tuolumne | 11,054 | Community | Surface water |
| Tud - Columbia Water System | Tuolumne | 5,463 | Community | Surface water |
| Peppery Bar and Grill, the | Tuolumne | 4,500 | Transient non-community | Groundwater |
| Cdcr - Sierra Conservation Center | Tuolumne | 3,571 | Community | Surface water |
| Groveland Community Serv Dist | Tuolumne | 3,400 | 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, “Mi Wuk Heights Mwc, PWSID CA5500060, California”, https://aquacensus.com/water-systems/california/mi-wuk-heights-mwc-ca5500060 (data as of October 1, 2026).