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Counties → Connecticut

New Haven County, Connecticut

SDWIS compliance plate

Sheet CT009 · New Haven County 212 sys · 17,543 viol · #93/3254

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

  • VIOL-SEVERE 94.3% flagged
  • HEALTH-LOW 7.9% health
  • RANK-TOP #93/3254
  • PHOTO-FINISH ±0.9 pp
  • PFAS-HIGH 70.0% detect
  • SRC-GW GW lead 94%
  • SYS-LARGE 212 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Middlesex County ( -0.9 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, New Haven County ranks #93 of 3,254 counties by people served, and #3 of 8 counties in Connecticut. See methodology · corpus placement.

New Haven County standing, mid-flagged corpus third

Flagged-system rate 94.3% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 7.9% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 70.0% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #93 of 3,254 · #3 of 8 in Connecticut.

Flagged-rate neighbourhood around New Haven County

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

0% 20% 40% 60% 80% 100% New London · lowest Middlesex · near Litchfield · near Hartford · highest 91.4% 92.2% 93.5% 94.3% 96.2% 96.4% 97.3%

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

Water Systems

System Name Population Violations PFAS
Regional Water Authority 418,900 62 Detected
Waterbury Water Department 107,271 35 Clean
Meriden Water Division 58,441 119 Detected
Wallingford Water Department 37,267 188 Detected
Ctwc - Shoreline Region-Guilford System 33,975 575 Detected
Ctwc - Naugatuck Region-Central System 22,735 15 Clean
Aquarion-Valley 13,080 26 Detected
Heritage Water Company 7,300 80 Detected
Wolcott Water Department 2,550 137 -
Ctwc - Legend Hill System 1,368 118 -
Aquarion-East Derby 1,101 32 -
Nonnewaug High School 887 52 -
Southbury Training School 816 370 -
Alcott School 638 108 -
Quonnipaug Hills - Main System 564 409 -
Bethany Community School 550 0 -
Calvary Fellowship Southbury 540 6 -
Melissa Jones School 484 79 -
Amity Regional Junior High School 475 164 -
Harmony Acres Mobile Home Park 465 232 -
Aquarion-Lakeside 455 165 -
Tyrrell Middle School 454 107 -
Aquarion-Oxford Towne Center 449 6 -
Frisbie Elementary School 446 17 -
Quassy Amusement Park 431 15 -
Middlebury Elementary School 412 90 -
Camp Laurelwood 400 67 -
125-131 Bradley Road - Woodbridge 385 1,147 -
The Country School (Main Building) 360 21 -
The Lake House 300 10 -
Arrowhead by the Lake Association, Inc. 288 117 -
Tranquility Vineyard and Winery 257 0 -
South Broad Street Service Area 250 9 -
Blue Trails Water Association 228 178 -
Church of Latter Day Saints, Woodbridge 220 22 -
Countryside Apartments 218 218 -
Aquarion-Clearview Hills 215 8 -
Laticrete International 200 347 -
171 Amity Road 180 246 -
YMCA - Camp Mountain Laurel 180 63 -
Church of Latter Day Saints, Madison 172 0 -
Kettletown S.p./Beach Well 167 34 -
Kettletown S.p./Campground Well 167 27 -
Christ the Savior Orthodox Church 150 116 -
Bethany Mobile Home Park 138 158 -
Idleview Mobile Home Park 138 4 -
Children's Village - Boundline 130 29 -
Great Expectations Day Care & Annex 125 44 -
New Life Church - South Ridge Complex 122 15 -
Church of Latter Day Saints, Southbury 121 7 -

Compare beyond Connecticut

Mid-flagged peers for New Haven County

Cross-state counties nearest New Haven County on flagged-system share (94.3%) and cumulative violation count (17,543). 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.