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Counties → California

Mono County, California

SDWIS compliance plate

Sheet CA051 · Mono County 93 sys · 2,450 viol · #581/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-CLEAN · SRC-GW · SYS-MID · BOOK-FULL

  • VIOL-SEVERE 95.7% flagged
  • HEALTH-LOW 12.9% health
  • RANK-TOP #581/3254
  • PHOTO-FINISH ±0.2 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-GW GW lead 94%
  • SYS-MID 93 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Monterey County (+ 0.2 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Mono County ranks #581 of 3,254 counties by people served, and #38 of 58 counties in California. See methodology · corpus placement.

Mono County standing, mid-flagged corpus third

Flagged-system rate 95.7% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 12.9% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #581 of 3,254 · #38 of 58 in California.

Flagged-rate neighbourhood around Mono County

Lowest/highest poles plus in-state counties nearest Mono County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Alpine · lowest Mono · this county San Mateo · near Sutter · highest 70% 94.9% 95.7% 95.9% 96.2% 96.2% 97.1%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

System Name Population Violations PFAS
Robinson Creek Campground 50,562 22 -
Mammoth Cwd 8,234 13 Clean
Mammoth Mountain Ski Area - Outpost 14 7,736 31 Clean
Trumbull Lake Campground 7,423 28 -
June Lake PUD - Down Canyon 2,810 29 -
June Lake PUD Village 2,763 30 -
Bootleg Campground 2,467 18 -
Chris Flat Campground 1,585 21 -
Leavitt Campground 1,405 28 -
Usmc/Mtn Warfare Trng Ctr - Bridgeport 1,200 0 -
Mammoth Lakes Basin 1,000 2 -
East Fork Campground 750 9 -
Lee Vining Public Utility District 672 3 -
French Camp Campground 600 2 -
Bridgeport PUD 524 189 -
June Mountain Ski Area - Lower 514 53 -
June Mountain Ski Area - Upper 514 20 -
Mountain Meadows MWC 505 30 -
Annett's Mono Village 500 28 -
Convict Lake Campground 440 31 -
Usmc - Housing Coleville 424 3 -
Big Bend Campground 345 16 -
Twin Lakes Enterprises 325 39 -
Saddlebag Lake Campground 325 24 -
Lower Rock Creek Mutual Water Co. 310 42 -
Cal Trans - Crestview Rest Area 300 9 -
Csp - Bodie Shp 271 2 -
Crowley Lake Trailer Park 230 38 -
Coleville High School 216 22 -
Usfs Lee Vining Ranger Station 200 19 -
Tuff Campground 180 0 -
Crowley Lake Mutual Water Company 175 42 -
McGee Creek Campground 168 14 -
Tom's Place 156 56 -
Big Meadow Campground 154 19 -
Birchim Community Service District 150 52 -
McGee Creek Mobile Home Park 146 32 -
White Mountain Mutual Water Company 142 8 -
Grant Lake Marina 130 17 -
Topaz Lake RV Park 127 27 -
Pine Grove Campground 120 15 -
Hunewill Guest Ranch 115 24 -
Twin Lakes Resort 100 41 -
Hunewill's Doc and Al's Resort 100 22 -
Pokonobe Lodge Restaurant/Store 100 11 -
Crowley Lake General Store 100 24 -
Bridgeport Reservoir Marina and Cg 90 14 -
Wheeler Crest Csd 86 13 -
Sierra East HOA 84 90 -
Crystal Crag Water & Development Assoc. 75 27 -

Compare beyond California

Mid-flagged peers for Mono County

Cross-state counties nearest Mono County on flagged-system share (95.7%) and cumulative violation count (2,450). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.