County · California
Mono County, California: drinking water records
Explore EPA records for 19 community water systems across 8 ZIP codes in Mono County, then find water-testing resources and available recent monitoring-station readings.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
Drinking-water records
EPA survey and compliance records are historical reports. UCMR 5 results are available for 1 of the 19 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems in this county
All 19 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Mammoth Cwd CA2610001 | 8,234 | 300 | 0 | 0 | 0 ppbbelow the action level |
| June Lake PUD - Down Canyon CA2610004 | 2,810 | 0 | 0 | 3 | 2 ppbbelow the action level |
| June Lake PUD Village CA2610002 | 2,763 | 0 | 0 | 2 | 2.7 ppbbelow the action level |
| Bridgeport PUD CA2610003 | 524 | 0 | 0 | 9 | 1.9 ppbbelow the action level |
| Lower Rock Creek Mutual Water Co. CA2600538 | 310 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Crowley Lake Trailer Park CA2600547 | 230 | 0 | 0 | 1 | 9.4 ppbbelow the action level |
| Utu Utu Gwaitu Paiute Tribe 090600159 | 222 | 0 | 0 | 16 | 5 ppbbelow the action level |
| Sierra East HOA CA2600622 | 84 | 0 | 0 | 21 | 4.4 ppbbelow the action level |
| Usmc/Mtn Warfare Trng Ctr - Bridgeport CA2610700 | 1,200 | 0 | 0 | 0 | 1.6 ppbbelow the action level |
| Lee Vining Public Utility District CA2610005 | 672 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Mountain Meadows Mwc CA2600620 | 505 | 0 | 0 | 0 | 4.4 ppbbelow the action level |
| USMC - Housing Coleville CA2610701 | 424 | 0 | 0 | 0 | 0.9 ppbbelow the action level |
| Crowley Lake Mutual Water Company CA2600546 | 175 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Birchim Community Service District CA2600501 | 150 | 0 | 0 | 0 | 5.2 ppbbelow the action level |
| White Mountain Mutual Water Company CA2600621 | 142 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Wheeler Crest CSD CA2600714 | 86 | 0 | 0 | 0 | 1.6 ppbbelow the action level |
| Lundy Mutual Water Company CA2600532 | 70 | 0 | 0 | 0 | 3.7 ppbbelow the action level |
| Cold Water Canyon Mwc CA2600733 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Chalfant Valley West M.W.C. CA2600699 | 45 | 0 | 0 | 0 | 0 ppbbelow the action level |
USGS · Monitoring stations
The water, more recently.
Available station readings in Mono County, California. Each measurement keeps its time, unit and original source.
These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.
Recent observations load when this section comes into view.
How these readings update
We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.
Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.
Your next step
Water testing, reports & local help.
Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.
Official national directories
Water testing
Find your state’s private-well program
EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.
Water testing
Find a certified drinking-water laboratory
Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.
Public records
Find your utility’s Consumer Confidence Report
EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.
Public records
Explore USGS water observations
Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.
A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.
Understand water testing and laboratory reportsResource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction
Explore your area
Local coverage in Mono County
8ZIP areas in this overview
Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.
Towns and communities
- Benton
- Bridgeport
- Chalfant
- Coleville
- June Lake
- Mammoth Lakes
- Mono City
- Topaz
View ZIP areas and understand coverage
- 93512Benton
- 93514Chalfant
- 93517Bridgeport
- 93529June Lake
- 93541Mono City
- 93546Mammoth Lakes
- 96107Coleville
- 96133Topaz
These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.
Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.
Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.