Public water system · CA2209065
ActiveMid - Mc Swain Rec Area
At a glance
Mid - Mc Swain Rec Area (PWSID CA2209065) is an active transient non-community water system in Mariposa County, California. It reports serving 1,119 people through 125 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,119
Service connections
125
Primary source
SW
Surface water
System type
TNCWS
Transient non-community water system
System record
How does Mid - Mc Swain Rec Area compare with other water systems in Mariposa County?
By EPA's size categories, Mid - Mc Swain Rec Area is a small system (501 to 3,300 people). Mariposa County has 67 active public water systems, and Mid - Mc Swain Rec Area is the 5th-largest of them by population served. Its population served is about 194% above the county average of 381 people per system, and accounts for 4.4% of the 25,508 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Mid - Mc Swain Rec Area is about 7.8 times 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. California has 3,016 active transient non-community water systems, 40% of the state's 7,479 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates Mid - Mc Swain Rec Area?
EPA lists Mid - Mc Swain Rec Area as owned by a local government. 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. 21 of the 67 active systems in Mariposa County (31%) are also owned by a local government.
Does Mid - Mc Swain Rec Area have drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2013. The violations listed here began between January 2003 and January 2013. By type: 6 monitoring and reporting. The contaminant or rule involved most often is Nitrate (5 of them). EPA lists 6 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 |
|---|---|---|---|---|
| 2013-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2011-04-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2011-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2003-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
All 6 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.
Mid - Mc Swain Rec Area: frequently asked questions
Who runs Mid - Mc Swain Rec Area?
Mid - Mc Swain Rec Area (PWSID CA2209065) is a transient non-community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Mid - Mc Swain Rec Area serve?
Mid - Mc Swain Rec Area reports serving 1,119 people through 125 service connections in Mariposa County, California.
Where does Mid - Mc Swain Rec Area get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Mid - Mc Swain Rec Area have any drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2013. 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 Mid - Mc Swain Rec Area'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 6 violations for this system; none is health-based, and the most recent began in January 2013. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Mid - Mc Swain Rec Area's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Mid - Mc Swain Rec Area 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 Mariposa County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Yosemite Nps-Glacier Point | Mariposa | 4,000 | Transient non-community | Surface water |
| Blm-Briceburg Water System | Mariposa | 3,196 | Transient non-community | Groundwater |
| Mariposa Public Utility Dist | Mariposa | 2,000 | Community | Surface water |
| Yosemite Nps-Bridalveil Fall | Mariposa | 1,163 | Transient non-community | Groundwater |
| Yosemite Nps-Badger Pass | Mariposa | 1,000 | Transient non-community | Groundwater |
| Yosemite Nps-Yosemite Valley | Mariposa | 1,000 | Community | Groundwater |
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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, “Mid - Mc Swain Rec Area, PWSID CA2209065, California”, https://aquacensus.com/water-systems/california/mid-mc-swain-rec-area-ca2209065 (data as of October 1, 2026).