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Counties → Pennsylvania

Montgomery County, Pennsylvania

SDWIS compliance plate

Sheet PA091 · Montgomery County 172 sys · 36,032 viol · #39/3254

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

  • VIOL-SEVERE 97.7% flagged
  • HEALTH-LOW 3.1% health
  • RANK-TOP #39/3254
  • PHOTO-FINISH ±0.1 pp
  • PFAS-HIGH 100.0% detect
  • SRC-GW GW lead 84%
  • SYS-LARGE 172 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Armstrong County ( -0.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Montgomery County ranks #39 of 3,254 counties by people served, and #3 of 68 counties in Pennsylvania. See methodology · corpus placement.

Montgomery County standing, mid-flagged corpus third

Flagged-system rate 97.7% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 3.1% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 100.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #39 of 3,254 · #3 of 68 in Pennsylvania.

Flagged-rate neighbourhood around Montgomery County

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

0% 20% 40% 60% 80% 100% Greene · lowest Tioga · near Montgomery · this county Sullivan · highest 66.7% 97.6% 97.6% 97.6% 97.7% 97.8% 100%

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

Water Systems

System Name Population Violations PFAS
Aqua PA Main System 822,600 453 Detected
North Penn Water Authority 91,941 209 Detected
PA American Norristown 88,885 92 Detected
North Wales Water Authority 72,496 422 Detected
Pottstown Borough Water Auth 36,000 172 Detected
Horsham Water&sewer Authority 26,000 572 Detected
Ambler Boro Water Dept 20,000 2,896 Detected
Aqua PA Hatboro 12,901 402 Detected
Aqua PA Superior Main System 11,400 1,406 Detected
Merck and Co Inc 8,550 70 Detected
Collegeville Trappe Joint Pwd 8,470 434 Detected
PA American Audubon 8,200 5,456 Detected
Telford Borough Authority 7,700 224 Detected
Schwenksville Borough Auth 5,200 158 Detected
Upper Hanover Water Authority 4,600 1,170 Detected
Aqua PA Perkiomen Township 3,600 136 Detected
Radisson Valley Forge Hotel 3,500 685 Detected
E Greenville Boro Water Dept 3,100 69 -
Red Hill Water Authority 2,500 761 -
Valley Forge Natl Park 2,300 101 -
Hatfield Quality Meats Inc 1,850 48 -
Constellation Nuclear Pwr Plnt 1,650 123 -
Upper Dublin High School 1,473 49 -
Pottstown Hosp Tower Health 1,425 10 -
Village of Neshaminy Falls 1,300 56 -
Parkhouse Nursing & Rehab Ctr 1,200 466 -
Aqua PA Perkiomen Woods 1,100 39 -
Spring Mountain Adventures 1,000 11 -
New Hanover Upper Fred E S 850 138 -
Aqua PA Upper Providence 810 0 -
Gilbertsville Elementary 800 134 -
Marlborough Elementary School 800 126 -
Jefferson Hospital Lansdale 700 25 -
Frederick Living 640 241 -
Camp Hart Musser Reservation 600 76 -
Fort Washington Elem School 532 20 -
Perkiomen Crossing 508 66 -
Aqua PA Superior Center Point 500 644 -
Salford Hills Elem School 500 486 -
Hickory Valley G C Snack Bar 500 7 -
Horsham Clinic 488 94 -
Biddle Air National Guard Base 440 178 -
Camp Hope for Kids 410 99 -
Limerick Diner 400 97 -
Indian Valley Country Club 400 45 -
Flourtown Swim Club 350 118 -
Camp Green Lane 350 104 -
Lehigh Valley Dairies Ntnc 328 67 -
Green Hill MHP 323 296 -
Avante Apartments 315 392 -

Compare beyond Pennsylvania

Mid-flagged peers for Montgomery County

Cross-state counties nearest Montgomery County on flagged-system share (97.7%) and cumulative violation count (36,032). 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.