PlainWater
Counties → Texas

Harris County, Texas

SDWIS compliance plate

Sheet TX201 · Harris County 1,292 sys · 78,495 viol · #3/3254

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

  • VIOL-SEVERE 86.3% flagged
  • HEALTH-LOW 6.5% health
  • RANK-TOP #3/3254
  • PHOTO-FINISH ±0.4 pp
  • PFAS-HIGH 50.2% detect
  • SRC-GW GW lead 82%
  • SYS-LARGE 1292 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Ector County (+ 0.4 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Harris County ranks #3 of 3,254 counties by people served, and #1 of 254 counties in Texas. See methodology · corpus placement.

Harris County standing, lower-flagged corpus third

Flagged-system rate 86.3% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 6.5% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 50.2% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #3 of 3,254 · #1 of 254 in Texas.

Flagged-rate neighbourhood around Harris County

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

0% 20% 40% 60% 80% 100% Howard · lowest Midland · near Ector · near Bee · highest 66.7% 85.7% 85.9% 86.3% 86.7% 87.3% 100%

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

Water Systems

System Name Population Violations PFAS
City of Houston 2,970,543 29 Detected
City of Pasadena 152,000 31 Detected
Clear Lake City Water Authority 89,702 12 Detected
City of Baytown 86,004 23 Detected
City of Houston Ud 5 - Kingwood 80,073 23 Clean
City of la Porte 36,569 4 Detected
City of Deer Park 34,495 60 Detected
Harris County MUD 165 30,483 4 Detected
City of Katy 25,253 6 Clean
Bridgestone MUD 24,528 13 Detected
Timber Lane Utility District 24,507 7 Clean
Northwest Harris County MUD 5 23,766 27 Detected
Harris County Fwsd 51 19,671 11 Detected
Cimarron MUD 19,338 3 Clean
City of West University Place 19,200 80 Detected
Harris County MUD 82 18,990 29 Clean
Northwest Park MUD 18,168 17 Clean
Clear Brook City MUD 18,108 40 Detected
City of Bellaire 18,090 8 Detected
Harris Montgomery Counties MUD 386 18,018 0 Clean
Harris County MUD 53 17,856 9 Detected
City of Tomball 17,532 8 Clean
City of South Houston 17,397 28 Detected
Harris County MUD 71 17,079 11 Clean
Harris County MUD 26 16,518 3 Clean
Harris County MUD 55 Heritage Park 16,392 20 Detected
Harris County MUD 167 15,837 90 Clean
City of Humble 15,616 6 Detected
Harris County Fwsd 61 15,400 7 Clean
Harris County MUD 200 Cranbrook 14,868 6 Detected
Harris County MUD 24 14,796 26 Detected
Cnp Utility District 14,718 6 Detected
Harris County MUD 285 14,268 4 Detected
City of Houston Willow Chase 14,169 8 Clean
Harris County MUD 105 14,151 80 Detected
Meadowhill Regional MUD 13,863 25 Clean
Harris County Wcid 21 13,845 38 Detected
Remington MUD 1 13,743 0 Detected
City of Webster 13,710 9 Detected
City of Seabrook 13,560 1 Detected
Newport MUD 13,191 17 Detected
Harris County MUD 168 13,029 10 Clean
Tomball Isd Cypress Rosehill Plant 12,600 6 -
Harris County MUD 1 12,342 1 Clean
Northampton MUD 12,162 5 Clean
Harris County MUD 157 12,087 10 Detected
Harris County MUD 368 11,835 7 Detected
Harris County MUD 81 11,514 20 Clean
Memorial Villages Water Authority 11,382 15 Detected
Harris County Utility District 6 11,262 5 Detected

Compare beyond Texas

Lower-flagged peers for Harris County

Cross-state counties nearest Harris County on flagged-system share (86.3%) and cumulative violation count (78,495). 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.