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Counties → Connecticut

Middlesex County, Connecticut

SDWIS compliance plate

Sheet CT007 · Middlesex County 276 sys · 25,593 viol · #589/3254

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

  • VIOL-SEVERE 93.5% flagged
  • HEALTH-LOW 8.7% health
  • RANK-TOP #589/3254
  • PHOTO-FINISH ±0.9 pp
  • PFAS-HIGH 50.0% detect
  • SRC-GW GW lead 98%
  • SYS-LARGE 276 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: New Haven County (+ 0.9 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Middlesex County ranks #589 of 3,254 counties by people served, and #6 of 8 counties in Connecticut. See methodology · corpus placement.

Middlesex County standing, mid-flagged corpus third

Flagged-system rate 93.5% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 8.7% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 50.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #589 of 3,254 · #6 of 8 in Connecticut.

Flagged-rate neighbourhood around Middlesex County

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

0% 20% 40% 60% 80% 100% New London · lowest Windham · near New Haven · near 91.4% 91.8% 92.2% 93.5% 94.3% 97.3%

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

Water Systems

System Name Population Violations PFAS
Middletown Water Department 41,019 26 Clean
Cromwell Fire District Water Department 14,316 232 Detected
Ctwc - Shoreline Region-Chester System 5,030 156 Clean
Portland Water Department 5,010 65 Detected
Connecticut Valley Hospital 2,928 149 -
Pratt & Whitney 2,800 187 -
Durham Center Division 1,601 298 -
Haddam Killingworth Inter/Middle School 808 308 -
Haddam Meadows S.p. 780 50 -
Ctwc - Jensens Beechwood System 750 447 -
Ctwc - Spice Hill Division 712 210 -
YMCA Camp Ingersoll 653 5 -
Ctwc - Lake Hayward 650 86 -
Haddam-Killingworth High School 642 85 -
Nathan Hale-Ray Middle School 620 7 -
East Haddam Elementary School 600 17 -
East Hampton High School 568 332 -
Valley Regional High School 565 23 -
Edgemere Condominium Assn., Inc. 540 297 -
Wadsworth Falls/Bathroom Well 527 13 -
Yeshiva of Waterbury-Durham Campus 490 1,081 -
East Hampton Middle School 487 118 -
Nathan Hale-Ray High School 461 4 -
Whelen Engineering Co 400 33 -
John Winthrop Junior High School 400 20 -
Frederick Brewster School 370 33 -
East Hampton Wpca - Village Center 366 264 -
Burr District Elementary School 364 381 -
East Hampton Wpca - Royal Oaks System 328 303 -
Killingworth Elementary School 315 21 -
Deer Lake Outdoor Center Dining - Well 2 300 10 -
John Lyman School 285 19 -
Ctwc - Banner Village 265 43 -
Ctwc - Shoreline Reg-Chester Vllg West 216 94 -
Heritage Cove Condominiums 208 93 -
Ctwc - Baker Hill Division 203 201 -
Hobson Motzer, Inc. 200 239 -
732 Middlesex Turnpike 200 20 -
The Independent Day School 199 6 -
Aquarion-East Hampton 189 5 -
St. Clements Marina 180 0 -
Mallard Cove Condominium Assn. 177 262 -
Dd Durham 156 10 -
East Haddam Municipal Center 154 512 -
Ctwc - Westchester East 153 349 -
Goodspeed Opera House 150 332 -
Clinton Nurseries - Secondary System 143 11 -
Cobalt Lodge Healthcare & Rehab Center 130 204 -
Chestelm Health & Rehabilitation Center 120 47 -
Evergreen Springs - System #4 110 356 -

Compare beyond Connecticut

Mid-flagged peers for Middlesex County

Cross-state counties nearest Middlesex County on flagged-system share (93.5%) and cumulative violation count (25,593). 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.