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Counties → California

San Bernardino County, California

SDWIS compliance plate

Sheet CA071 · San Bernardino County 318 sys · 4,611 viol · #13/3254

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

  • VIOL-SEVERE 91.5% flagged
  • HEALTH-MID 40.1% health
  • RANK-TOP #13/3254
  • PHOTO-FINISH ±0.1 pp
  • PFAS-MID 49.0% detect
  • SRC-GW GW lead 86%
  • SYS-LARGE 318 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Santa Clara County (+ 0.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, San Bernardino County ranks #13 of 3,254 counties by people served, and #5 of 58 counties in California. See methodology · corpus placement.

San Bernardino County standing, lower-flagged corpus third

Flagged-system rate 91.5% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 40.1% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 49.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #13 of 3,254 · #5 of 58 in California.

Flagged-rate neighbourhood around San Bernardino County

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

0% 20% 40% 60% 80% 100% Alpine · lowest Santa Clara · near Sutter · highest 70% 91.4% 91.5% 91.6% 91.7% 91.9% 97.1%

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

Water Systems

System Name Population Violations PFAS
San Gabriel Valley WC - Fontana 237,700 3 Clean
San Bernardino City 214,665 2 Detected
Cucamonga Valley Water District 211,069 5 Clean
Ontario Municipal Utilities Company 185,010 9 Detected
Victorville Water District 135,983 13 Clean
San Bernardino Valley WD 109,608 2 -
East Valley Water District 108,629 13 Detected
West Valley Water District 104,498 19 Clean
Hesperia WD 100,744 7 Detected
Chino, City Of 86,435 44 Clean
Big Bear Administration 81,075 12 -
Upland, City Of 78,376 10 Detected
Redlands City MUD-Water Div 78,025 11 Detected
Chino Hills, City Of 76,414 43 Clean
Snow Summit 75,500 45 -
Liberty Utilities (Av Ranchos) Corp. 64,469 2 Clean
Park Moabi 64,267 2 -
Monte Vista WD 56,017 27 Detected
Rialto, City Of 54,453 6 Detected
Yucaipa Valley Water District 52,010 19 Detected
Colton, City Of 46,525 3 Detected
Adelanto, City Of 39,930 40 Detected
Golden State Water Co - Barstow 32,547 2 Detected
HI Desert WD 26,411 17 Detected
Big Bear Lake Dwp - Big Bear System 26,132 3 Detected
Loma Linda, City Of 25,129 9 Clean
Calico Ghost Town 24,623 131 -
Phelan Pinon Hills Csd 24,285 3 Clean
Riverside Highland Water Company 20,188 6 Detected
Twentynine Palms Water District 18,795 254 Clean
US Army Fort Irwin 15,701 146 Clean
Loma Linda University 15,368 5 Detected
Usmc - 29 Palms 15,248 11 Clean
Thousand Pines Christian 15,034 5 -
Sbdno County Service Area 64 14,911 7 Clean
Hanna Flats Campground 14,380 0 -
Muscoy MWC No. 1 13,000 45 Clean
Sbdno County Service Area 70J 12,843 5 Clean
Big Bear City Csd 12,738 1 Detected
Crestline Village Cwd - Division 10 11,650 10 Detected
California Institution for Men 10,667 35 Clean
Green Valley Campground 9,939 0 -
Needles, City Of 8,766 17 Clean
Western Heights Water Company 7,705 6 Clean
Lake Arrowhead Csd 7,038 0 Detected
Arrowhead Regional Medical Center 7,000 4 -
Joshua Basin Water District 6,640 9 Clean
YMCA Camp Whittle 6,466 15 -
Helendale Community Service District 6,347 51 Detected
Golden State Water Co - Apple Vly South 6,208 1 Clean

Compare beyond California

Lower-flagged peers for San Bernardino County

Cross-state counties nearest San Bernardino County on flagged-system share (91.5%) and cumulative violation count (4,611). 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.