How many water violations are in Hays County?

Hays County has 5,506 total drinking water violations across 124 water systems, of which 475 are health-based violations. 81.5% of systems have at least one violation.

How many people get water from Hays County systems?

Water systems in Hays County serve approximately 306,942 people through 124 public water systems.

Has PFAS been detected in Hays County water?

Under EPA UCMR5, 5 of 11 tested systems in Hays County had at least one PFAS detection (45.5% of the UCMR5-tested subset - not of all 124 SDWIS systems).

What types of water sources supply Hays County?

Water systems in Hays County use GW (77 systems), SW (46 systems), Unknown (1 systems) as their primary water sources.

Are health-based violations serious?

Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 8.6% of Hays County's violations are health-based. Among counties with any SDWIS violations, this extract puts Hays County in the lower health-based share band. Not all violations indicate immediate health risk, but they require corrective action.

Where does Hays County sit among U.S. counties for water-system population?

According to EPA SDWIS county population served used on /counties, Hays County ranks #225 of 3,254 counties by people served, and #19 of 254 counties in Texas. Ordinals use the same total_population DESC sort as the counties directory. See /methodology#corpus-placement.

Counties → Texas

Hays County, Texas

Compiled by PlainWater · May 15, 2026

SDWIS compliance plate

Sheet TX209 · Hays County 124 sys · 5,506 viol · #225/3254

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

VIOL-SEVERE 81.5% flagged
HEALTH-LOW 8.6% health
RANK-TOP #225/3254
PHOTO-FINISH ±0.5 pp
PFAS-MID 45.5% detect
SRC-GW GW lead 62%
SYS-LARGE 124 systems
BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Liberty County (+ 0.5 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Hays County ranks #225 of 3,254 counties by people served, and #19 of 254 counties in Texas. See methodology · corpus placement.

Hays County standing, lower-flagged corpus third

Flagged-system rate 81.5% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 8.6% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 45.5% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #225 of 3,254 · #19 of 254 in Texas.

Water Systems

System Name	Population	Violations	PFAS
City of San Marcos	72,970	35	Detected
City of Kyle	52,000	17	Detected
Texas State University - San Marcos	43,552	52	Clean
Goforth Sud	34,893	56	Detected
County Line Sud	19,609	26	Detected
City of Buda	13,830	142	Detected
Dripping Springs WSC	8,037	39	Clean
Plum Creek	7,065	24	Clean
Wimberley WSC	5,334	18	Clean
Hays Cisd Jack C Hays High School	4,048	143	Clean
Hays County Wcid 2	3,381	1	-
Woodcreek Utility Co 2	3,096	207	-
Hays County Wcid 1	2,850	5	-
Woodcreek Utility Co 1	2,700	43	-
South Buda Wcid 1	2,517	10	-
Headwaters at Barton Creek	2,315	21	-
Cimarron Park Water	2,079	3	-
Mid-Tex Utilities	1,569	10	-
Reunion Ranch Wcid	1,557	14	-
Meadow Woods Water Supply	1,554	22	-
Leisurewoods Water	1,338	29	-
Salt Lick Bar B Q	1,143	126	-
Oak Meadows	954	17	-
La Ventana Water Supply System	747	20	Clean
Ruby Ranch WSC	738	12	-
City of Mountain City	725	45	-
Elliott Ranch Water System	639	8	-
Promiseland Church San Marcos	625	30	-
Cedar Oak Mesa WSC	497	57	-
Sierra West Subdivision	495	29	-
Goldenwood West WSC	462	74	-
San Marcos Baptist Academy	450	27	-
Chaparral Water System Hays	444	220	-
Hays Youth Sports Complex	400	76	-
Huntington Estates	378	6	-
Trattoria Lisina	350	36	-
Hawks Shadow Winery	350	12	-
Oak Forest WSC	339	34	-
River Oaks Ranch	336	10	-
Southwest Territory	315	22	-
Mountain Crest Water	309	4	-
Hays Hills Baptist Church	300	49	-
Sellers Wine Bar	300	6	-
Henly Baseball Complex	300	34	-
Horseshoe Ridge RV Resort	300	0	-
Solaro Estate Winery	289	0	-
Camp Young Judaea	285	54	-
City of Hays	270	40	-
Skyline Ranch Estates WSC	261	28	-
Stripes 1509	250	16	-

Compare beyond Texas

Lower-flagged peers for Hays County

Cross-state counties nearest Hays County on flagged-system share (81.5%) and cumulative violation count (5,506). 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

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

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.