Hard Water Map

Texas Water Hardness by County

Water in Texas has a median hardness of 200 mg/L as CaCO₃ — "very hard" on the USGS scale — based on 116,518 measurements at 8,600 monitoring stations. Childress County has the state's hardest measured water (1600 mg/L); Camp County the softest (19). Rank: #14 of the 50 states and D.C.

Texas water hardness map — what the numbers mean. Data verified 2026-07-22.

Of Texas's 183 measured counties, 110 very hard, 26 hard, 28 moderately hard, and 19 soft. The hardest are Childress County (1600 mg/L), King County (1600), and Reeves County (1600). Camp County is the softest at 19 mg/L (soft).

About 69% of Texas's roughly 28 million residents in counties with gate-passing hardness data live where tap water is hard or worse.

Statewide, Texas's median works out to 11.7 grains per gallon and ranks #14 of the 50 states and D.C. Across 116,518 measurements at 8,600 stations — 17,607 of them since 2000 — the middle 80% of readings fall between 47.4 and 670 mg/L. The public record runs from 1907 to 2023.

See where Texas sits nationally on the national map, or what its number means on the hardness scale.

Download the Texas water hardness map (PNG) — Water hardness by county in Texas: 183 counties mapped from USGS/EPA data, statewide median 200 mg/L (very hard); darker counties have harder water.

By county

Water hardness by county

The table lists all 183 measured Texas counties, hardest first. Their medians span 1600 mg/L in Childress County to 19 in Camp County — a 84.2× range. 61 more Texas counties lack gate-passing data.

County water hardness, hardest first — median mg/L as CaCO₃.
CountyMedianBandResultsSitesNewest
Childress County1600Very hard52491997
King County1600Very hard1,358432011
Reeves County1600Very hard446102017
Collingsworth County1500Very hard38222006
Wichita County1160Very hard81382023
Cottle County1100Very hard84172011
Foard County1100Very hard25761996
Stonewall County1100Very hard2,712242002
Kent County970Very hard359221996
Knox County950Very hard1,107532012
Baylor County912Very hard1,412112018
Pecos County768Very hard395842017
Howard County705.5Very hard94132017
Concho County660Very hard34422003
Terry County642Very hard21212014
Hudspeth County619Very hard115392007
Jones County590Very hard1,26182023
Coke County580Very hard1,063202003
Mitchell County580Very hard1,976152003
Runnels County580Very hard818102003
Nueces County550Very hard466752008
Gaines County547Very hard19192016
Garza County517Very hard49352016
Presidio County508Very hard189182014
Throckmorton County496.5Very hard9022023
Wheeler County495Very hard27752016
Hemphill County490Very hard21622021
Palo Pinto County480.5Very hard71482018
Shackelford County470Very hard2,105152023
Yoakum County464.5Very hard22222016
Parker County436Very hard403111997
Lubbock County435Very hard224172020
Hood County420Very hard41061997
Brown County419Very hard20762017
Lamb County379Very hard10102003
Somervell County374Very hard7332004
Cameron County366Very hard562202023
Grayson County320Very hard846122023
Kinney County320Very hard83282017
Karnes County300.5Very hard635182016
Goliad County290Very hard787142016
Hays County290Very hard1,1881392022
Hidalgo County290Very hard56632000
Potter County290Very hard1,283102023
Val Verde County288Very hard1,516372017
Bandera County284Very hard124252016
Bosque County280Very hard358112020
Duval County280Very hard87652013
Tom Green County280Very hard272512023
Haskell County276.5Very hard1621996
Johnson County276Very hard6232016
Brewster County270Very hard190302010
Culberson County270Very hard3701102014
Gray County270Very hard16142021
Oldham County270Very hard27942001
Starr County270Very hard84692005
Bexar County262Very hard5,7425432023
Blanco County260Very hard12962021
Caldwell County260Very hard7681002016
Comal County260Very hard1,3071962023
Stephens County260Very hard2,242232023
Webb County260Very hard412402013
Zapata County260Very hard9962000
Hutchinson County258Very hard1,000182020
Falls County250Very hard37721997
Hill County250Very hard1,623152005
Kendall County250Very hard32151997
McMullen County250Very hard596642016
Moore County250Very hard314162021
Travis County250Very hard3,3531272023
Burnet County247Very hard131142016
Coryell County246Very hard6351998
Refugio County240Very hard1,112922013
Guadalupe County236Very hard2891002023
Frio County235Very hard90402015
Ochiltree County234Very hard1162021
Medina County231Very hard7021592023
Galveston County230Very hard92242013
Hartley County230Very hard47112020
Menard County230Very hard1132017
Uvalde County230Very hard1,1201762023
Kerr County226Very hard35182017
Comanche County225.5Very hard36672006
El Paso County221Very hard8261842023
Aransas County220Very hard2241052013
Lipscomb County220Very hard2782019
Victoria County220Very hard85192010
Sherman County219Very hard1692021
Live Oak County214Very hard46382010
Bastrop County213Very hard4441852015
Donley County210Very hard156101999
Lamar County210Very hard38242018
Matagorda County210Very hard7571922013
Wharton County210Very hard375741995
Milam County209.5Very hard566102015
Grimes County205Very hard1481232013
Hale County204Very hard12102016
Williamson County202Very hard835692022
Brazoria County200Very hard1,0733342012
Edwards County200Very hard1192017
Real County196Very hard13102010
Freestone County195Very hard717252019
Hansford County195Very hard8862019
Bell County190Very hard1,001352022
Brooks County190Very hard134692013
Fort Bend County190Very hard1,264922023
Jim Wells County185Very hard138152013
Dallam County183Very hard1392020
Briscoe County180Very hard10032001
DeWitt County180Very hard449102013
Atascosa County170Hard177822017
Clay County170Hard1,07572016
Fannin County170Hard7142023
Chambers County160Hard5663832014
Dallas County160Hard2,702532023
Irion County160Hard1042017
Wise County160Hard69162016
Dimmit County158Hard2592016
McLennan County156Hard424132016
Waller County154Hard39342014
Burleson County150Hard581692016
Callahan County150Hard2852016
Ellis County150Hard1,045192016
Gonzales County150Hard3491332021
Houston County143Hard613132017
Franklin County140Hard646172007
Van Zandt County140Hard528502023
Tarrant County138Hard2,1481052023
Collin County134Hard503232023
Kaufman County130Hard56852023
Madison County130Hard4042015
Zavala County126.5Hard1662016
Jackson County121Hard1,357672023
Erath County120Hard2032016
Henderson County120Hard440202018
Denton County118Moderately hard3,960432023
Rockwall County115Moderately hard43142023
Polk County110Moderately hard714272019
San Jacinto County110Moderately hard637172014
Limestone County105Moderately hard692721997
Lee County104.5Moderately hard42262011
Cooke County102Moderately hard690142023
Fayette County102Moderately hard1492016
Crosby County100Moderately hard2742001
Leon County100Moderately hard255282015
Liberty County99Moderately hard1,6501132023
Bowie County89.8Moderately hard11662008
Harris County87.5Moderately hard3,7513232023
Walker County82.3Moderately hard700112023
Robertson County80.5Moderately hard11642011
Hunt County80.1Moderately hard27252023
Kenedy County80Moderately hard134832013
Wood County80Moderately hard1,110592023
Hopkins County76.5Moderately hard17772001
Rusk County75Moderately hard211342015
Cass County74.8Moderately hard356512016
Montgomery County73.2Moderately hard2,0181402023
Wilson County71.8Moderately hard56162017
Morris County70.5Moderately hard194172007
Jefferson County69Moderately hard7102492023
Titus County62Moderately hard778232007
Jeff Davis County61.5Moderately hard58162010
Shelby County60Moderately hard5152015
Panola County58.1Soft654172018
Gregg County48Soft279142015
Anderson County47.5Soft151272023
Smith County47.3Soft152182023
Nacogdoches County45Soft327112015
Orange County45Soft3772062013
Cherokee County43Soft58362007
Angelina County41Soft1,268112015
Tyler County39.7Soft381152017
Sabine County36.9Soft44142004
Jasper County36Soft1,198562007
La Salle County36Soft139662016
Upshur County34.6Soft272172015
Newton County31.3Soft804292022
San Augustine County30.7Soft76122004
Harrison County29Soft408142015
Marion County28.2Soft469332018
Hardin County20Soft375112015
Camp County19Soft32142015

ZIP codes

ZIP codes in Texas

The ZIP codes below are grouped by the Texas county each mostly falls within (by land area). Each ZIP takes that county's measured median — shown in the group header — so this is a ZIP-to-county guide, not a separate reading for every ZIP. To check the water system serving a specific address, use the lookup.

Key: a † after a ZIP means it has no mapped community water system — usually a private-well area. Plain ZIPs are served by a mapped community water system.

Childress County · 1600 mg/L · Very hard

7920179230

King County · 1600 mg/L · Very hard

79236†

Reeves County · 1600 mg/L · Very hard

79718†79770†797727978079785†

Collingsworth County · 1500 mg/L · Very hard

79095†79251†

Wichita County · 1160 mg/L · Very hard

76301763027630676308763097631176354†76360†76367

Cottle County · 1100 mg/L · Very hard

79223†79248†

Foard County · 1100 mg/L · Very hard

79227

Stonewall County · 1100 mg/L · Very hard

79502†79540†

Kent County · 970 mg/L · Very hard

79518†79528†

Knox County · 950 mg/L · Very hard

76363†7637179505†79529†

Baylor County · 912 mg/L · Very hard

76380

Pecos County · 768 mg/L · Very hard

79730†79735†79743

Howard County · 705.5 mg/L · Very hard

79511†79720†797217973379748†

Concho County · 660 mg/L · Very hard

76837†768587686276866

Terry County · 642 mg/L · Very hard

79316†79345†79378†

Hudspeth County · 619 mg/L · Very hard

79839†79851†

Jones County · 590 mg/L · Very hard

7950179503795207952579553†79601†

Coke County · 580 mg/L · Very hard

76933†7694576953†

Mitchell County · 580 mg/L · Very hard

795127953279565†

Runnels County · 580 mg/L · Very hard

7682176865768757688279567

Nueces County · 550 mg/L · Very hard

78330783397834378347†7835178373783807840178402784047840578406784077840878409784107841178412784137841478415784167841778419

Gaines County · 547 mg/L · Very hard

79323†79342†79359†79360†

Garza County · 517 mg/L · Very hard

79330†79356

Presidio County · 508 mg/L · Very hard

79843†79845†79846†

Throckmorton County · 496.5 mg/L · Very hard

763727648376491

Wheeler County · 495 mg/L · Very hard

79011†79061†7907979096†

Hemphill County · 490 mg/L · Very hard

79003†79014†

Palo Pinto County · 480.5 mg/L · Very hard

7606776449†764537647276475†76484†

Shackelford County · 470 mg/L · Very hard

764307646479533†

Yoakum County · 464.5 mg/L · Very hard

79355†79376†

Parker County · 436 mg/L · Very hard

7600876020†76035†760667608276085†7608676087†76088†7643976487†76490†

Lubbock County · 435 mg/L · Very hard

79329†79350†79363†79364†7936679382†794017940279403†7940479406794107941179412794137941479415†79416†79423†79424

Hood County · 420 mg/L · Very hard

76048760497646276476†

Brown County · 419 mg/L · Very hard

76432†768017680276823768277685776890

Lamb County · 379 mg/L · Very hard

79031†7906479082†79312†79326†79339†79369†

Somervell County · 374 mg/L · Very hard

760437607076077

Cameron County · 366 mg/L · Very hard

78520785217852678535785507855278559†78566785677857578578†7858378586†785927859378597†

Grayson County · 320 mg/L · Very hard

75020750217505875076750907509275414†75459754897549175495762337624576264762687627176273

Kinney County · 320 mg/L · Very hard

78832†

Karnes County · 300.5 mg/L · Very hard

78111†78116†7811778118†7811978144†78151†

Goliad County · 290 mg/L · Very hard

77960†77963†77993†78107†

Hays County · 290 mg/L · Very hard

7861078619†78620†78640786667867678737

Hidalgo County · 290 mg/L · Very hard

785017850378504785167853778538785397854078541†785427854378549785577855878560†7856278563†78565785707857278573785747857678577785797858978595†7859678599

Potter County · 290 mg/L · Very hard

79010†79058†79101791027910379104791067910779108†7911179124†

Val Verde County · 288 mg/L · Very hard

78837†78840†78841†78842†7884378871†

Bandera County · 284 mg/L · Very hard

78003†78055†78063†78883†78884†78885†

Bosque County · 280 mg/L · Very hard

7663476637†76649†76652†7666576671†76689†76690†

Duval County · 280 mg/L · Very hard

78341†78349†78357†78376†78384†

Tom Green County · 280 mg/L · Very hard

76861†76901†76902†769037690476905769087690976934†7693776939†7694076955†7695776958†

Haskell County · 276.5 mg/L · Very hard

76388†7952179539†79544†79547†79548

Johnson County · 276 mg/L · Very hard

76009760287603176033†7604476050†7605876059760617608476093

Brewster County · 270 mg/L · Very hard

79830†7983279834†79842†79852†

Culberson County · 270 mg/L · Very hard

79847†79855†

Gray County · 270 mg/L · Very hard

79002†79054†79057†79065†79066†

Oldham County · 270 mg/L · Very hard

79001†79092†

Starr County · 270 mg/L · Very hard

78536†78545†7854778548†78582†78584†78585†78588†78591†

Bexar County · 262 mg/L · Very hard

7800278023†7807378101781097811278148781507815278154782017820278203782047820578207782087820978210782117821278213782147821578216782177821878219782207822178222782237822478225782267822778228782297823078231782327823378234782357823678237782387823978240782427824378244782457824778248782497825078251782527825378254782557825678257†782587825978260782617826378264

Blanco County · 260 mg/L · Very hard

78606†78635†78636†78663†

Caldwell County · 260 mg/L · Very hard

78616†786227864478648†786557865678661

Comal County · 260 mg/L · Very hard

78070†78132†78133†781637826678623†

Stephens County · 260 mg/L · Very hard

7642476429

Webb County · 260 mg/L · Very hard

78019†780407804178043†78044†78045†7804678344†78369†78371†

Zapata County · 260 mg/L · Very hard

78067†7807678564

Hutchinson County · 258 mg/L · Very hard

79007†79008†79062†79078†79080†79083†

Falls County · 250 mg/L · Very hard

765247657076632†7665676661†76680†76682†76685†

Hill County · 250 mg/L · Very hard

7605576621†7662276627†766287663176636†7664576648766507666076666766737667676692

Kendall County · 250 mg/L · Very hard

78004†78006†780137801578027†78074†

McMullen County · 250 mg/L · Very hard

78007†78072†

Moore County · 250 mg/L · Very hard

79013†79029†

Travis County · 250 mg/L · Very hard

78617†7864178645†78652†786537866078669†7870178702787037870478705787127871978721787227872378724†78725787267872778728†787307873178732787337873478735†78736†78738787397874178742†78744†7874578746787477874878749†7875078751787527875378754†78756787577875878759

Burnet County · 247 mg/L · Very hard

78605†78608†78611†78654†

Coryell County · 246 mg/L · Very hard

765227652876544†765617656676596765977659876599

Refugio County · 240 mg/L · Very hard

77990†78340†78377†78393†

Guadalupe County · 236 mg/L · Very hard

78108781237812478130781557863878670

Frio County · 235 mg/L · Very hard

78005†78017†78057†78061†

Ochiltree County · 234 mg/L · Very hard

79033†79070†79093†

Medina County · 231 mg/L · Very hard

78009†780167803978056†78059780667885078861†78886

Galveston County · 230 mg/L · Very hard

77510†77517†7751877539775467755077551†77554775557756377565†77568775737759077591776177762377650

Hartley County · 230 mg/L · Very hard

79018†79044†

Menard County · 230 mg/L · Very hard

76848†76859†

Uvalde County · 230 mg/L · Very hard

78801†78802†78838†78870†78881†

Kerr County · 226 mg/L · Very hard

78010†78024†7802578028†78029†78058†

Comanche County · 225.5 mg/L · Very hard

76436†7644276444†76452†76455†76474

El Paso County · 221 mg/L · Very hard

79821†79835†798367983879849798537990179902799037990479905799067990779908799117991279915799167991879920†7992279924799257992779928799307993279934799357993679938†

Aransas County · 220 mg/L · Very hard

77950†7835878382†

Lipscomb County · 220 mg/L · Very hard

79005†79024†79034†79046†79056†

Victoria County · 220 mg/L · Very hard

779017790477905†77951†77968†77973†77976†77977†77988†

Sherman County · 219 mg/L · Very hard

73960†79084†79086†

Live Oak County · 214 mg/L · Very hard

78022†7807178075†78383†

Bastrop County · 213 mg/L · Very hard

7860278612786217865078659786627895378957

Donley County · 210 mg/L · Very hard

79226†79237†79240†

Lamar County · 210 mg/L · Very hard

754117541675421†75434†75435754607546275468†75470754737547775486

Matagorda County · 210 mg/L · Very hard

77414†77415†77419†77428†77440†77456†77457†77458†7746577468†77482†77483†

Wharton County · 210 mg/L · Very hard

77420†77432†77435†77436†7743777443†77448†77453†77454†77455†77467†77488†

Milam County · 209.5 mg/L · Very hard

765187651976520†7652376556765677657777857

Grimes County · 205 mg/L · Very hard

773637783077831†77861†778687787577876†

Hale County · 204 mg/L · Very hard

7902179032†79041†7907279073†79250†79311†

Williamson County · 202 mg/L · Very hard

765277653076537765737657476578†786137861578626†78628786337863478642786647866578674786817871778729

Brazoria County · 200 mg/L · Very hard

77422†77430†77431†77480†77486†77511†775157753177534†77541†77566†77577†775787758177583†77584

Edwards County · 200 mg/L · Very hard

78880†

Real County · 196 mg/L · Very hard

78828†78833†78873†78879†

Freestone County · 195 mg/L · Very hard

7583875840†75848†758597586076693†

Hansford County · 195 mg/L · Very hard

79040†79081†

Bell County · 190 mg/L · Very hard

765017650276504765117651376534†765417654276543†765487654976554†7655776559765697657176579

Brooks County · 190 mg/L · Very hard

78353†78355†

Fort Bend County · 190 mg/L · Very hard

7705377406†7740777417†7744177444†77451†77459†77461†77464†77469†7747177476†77477774787747977481†7748977494†77498†77545

Jim Wells County · 185 mg/L · Very hard

78332†7834278372†78375†

Dallam County · 183 mg/L · Very hard

79022†79051†79087†

Briscoe County · 180 mg/L · Very hard

79255†79257†

DeWitt County · 180 mg/L · Very hard

7795477974†77994†77995†78141†78164

Atascosa County · 170 mg/L · Hard

78008†78011†78012†78026†780507805278062780647806578069

Clay County · 170 mg/L · Hard

76228†76305†7635776365†76377†

Fannin County · 170 mg/L · Hard

75413754187543875439754467544775449754527547575476†75479754887549075492

Chambers County · 160 mg/L · Hard

7751477523†775607758077597†77661†77665†

Dallas County · 160 mg/L · Hard

750017500675019750387503975040750417504275043750447504875050750517505275060750617506275063750807508175088†750897510475115751167513475137751417514675149751507515975172751807518175182752017520275203752047520575206752077520875209752107521175212752147521575216752177521875219752207522375224752257522675227752287522975230752317523275233752347523575236752377523875240752417524375244752467524775248752497525175253752547527075390

Irion County · 160 mg/L · Hard

76930†76941†

Navarro County · 160 mg/L · Hard

7510275105†751097511075144751537515576626766397664176679†76681

Wise County · 160 mg/L · Hard

76023†76071†76073†7607876225†76234†7626776426†76431

Dimmit County · 158 mg/L · Hard

78827†78830†78834†78836†

McLennan County · 156 mg/L · Hard

76624766307663376638†76640†766437665476655†7665776691767017670476705767067670776708767107671176712†76798

Waller County · 154 mg/L · Hard

77423774457744677466†77484†

Burleson County · 150 mg/L · Hard

77836778527786377878†77879†

Callahan County · 150 mg/L · Hard

76443764697950479510†

Ellis County · 150 mg/L · Hard

75101751197512575152†751547516575167760417606476065766237665176670†

Gonzales County · 150 mg/L · Hard

7812278140†78159†78614786297863278658†7867778959

Houston County · 143 mg/L · Hard

7583575844†75847†7584975851†7585675858†

Franklin County · 140 mg/L · Hard

754577548075487

Van Zandt County · 140 mg/L · Hard

75103†75117751277514075147†751697575475790

Tarrant County · 138 mg/L · Hard

750547526176001760027600576006760107601176012760137601476015760167601776018760217602276034760367603976040760517605276053760547606076063760927610276103761047610576106761077610876109761107611176112761147611576116761177611876119761207612376126761277612976131761327613376134761357613776140761487615576164761777617976180761827624476248

Collin County · 134 mg/L · Hard

75002750097501375023750247502575034750357506975070750717507275074750757507875082750937509475098751647516675173†75252752877540775409†754247544275454

Kaufman County · 130 mg/L · Hard

751147512675142†75143†75157751587516075161†

Madison County · 130 mg/L · Hard

75852†7786477872

Zavala County · 126.5 mg/L · Hard

78829†78839†78872†

Jackson County · 121 mg/L · Hard

77957†77961†77962†77969†77970†77971†77991†

Erath County · 120 mg/L · Hard

76401†764027643376446†76463†

Henderson County · 120 mg/L · Hard

7512475148†75156†7516375751†757527575675758†757707577875782

Denton County · 118 mg/L · Moderately hard

75007750107502275028750337503675056750577506575067750687507776201762037620576207762087620976210762267622776247†7624976258762597626276266

Rockwall County · 115 mg/L · Moderately hard

7503275087†7513275189

Polk County · 110 mg/L · Moderately hard

75934†75939†75960†77326†77335†77350†7735177360

San Jacinto County · 110 mg/L · Moderately hard

7732877331773597736477371

Limestone County · 105 mg/L · Moderately hard

76635†76642†766537666476667†766787668676687†

Lee County · 104.5 mg/L · Moderately hard

77853789427894678947†78948

Cooke County · 102 mg/L · Moderately hard

76238762407624176250762527625376263†76272

Fayette County · 102 mg/L · Moderately hard

78938†78940†78941†7894578949†78954†78956†78963†

Crosby County · 100 mg/L · Moderately hard

79322†79343†79357†

Leon County · 100 mg/L · Moderately hard

758317583375846758507585577855†7786577871†

Liberty County · 99 mg/L · Moderately hard

77327†77368†77369†77533†77535†77538†77561775647757577582†

Bowie County · 89.8 mg/L · Moderately hard

7550175503†7555975561†75567†7556975570†75573†75574

Harris County · 87.5 mg/L · Moderately hard

7700277003770047700577006770077700877009770107701177012770137701477015†77016770177701877019770207702177022770237702477025770267702777028770297703077031770327703377034770357703677037†770387703977040†77041770427704377044770457704677047770487704977050†77051770547705577056770577705877059†770607706177062770637706477065†7706677067770687706977070†770717707277073†770747707577076770777707877079770807708177082770837708477085770867708777088770897709077091770927709377094770957709677098770997720477336†77338773397734577346773737737577377†77379†77388†77389†77396†7740177429†7743377447†774497745077493†77502775037750477505†775067750777520†77521†7753077532†77536775477756277571775867758777598

Walker County · 82.3 mg/L · Moderately hard

773207733477340773417734277358†77367

Robertson County · 80.5 mg/L · Moderately hard

76629†77837†77856778597786777882†

Hunt County · 80.1 mg/L · Moderately hard

751357540175402754227542375428†75429†7545375474†75496

Kenedy County · 80 mg/L · Moderately hard

7833878385†

Wood County · 80 mg/L · Moderately hard

754107549475497757657577375783

Hopkins County · 76.5 mg/L · Moderately hard

7542075431754337543775471754787548175482†

Rusk County · 75 mg/L · Moderately hard

7564175652756547565875667†756807568175682756847568775689†75691†75784†

Cass County · 74.8 mg/L · Moderately hard

75551755557555675560755627556375564755657556675568755727563075656

Montgomery County · 73.2 mg/L · Moderately hard

7730177302†77303†7730477306†77316†77318†7735477355†773567735777362773657737277378†773807738177382†7738477385†7738677873†

Wilson County · 71.8 mg/L · Moderately hard

78113781147812178143781477816078161

Morris County · 70.5 mg/L · Moderately hard

755717563875668†

Jefferson County · 69 mg/L · Moderately hard

77613†7761977622†7762777629†77640776427765177655†7770177702777037770577706777077770877713

Titus County · 62 mg/L · Moderately hard

754557549375558

Jeff Davis County · 61.5 mg/L · Moderately hard

79734†79854†

Shelby County · 60 mg/L · Moderately hard

759357595475973†7597475975†

Panola County · 58.1 mg/L · Soft

75631†75633†75639†75642†7564375669†

Gregg County · 48 mg/L · Soft

75601756037560475605756477566275693

Anderson County · 47.5 mg/L · Soft

75763†75779758017580375839†75853758617588475886

Smith County · 47.3 mg/L · Soft

75701757027570375704†7570575706757077570875709757117575075762757717579175792

Nacogdoches County · 45 mg/L · Soft

757607578875937759437594475946†759617596275964†75965†

Orange County · 45 mg/L · Soft

77611†776307763277662†

Cherokee County · 43 mg/L · Soft

7575775759757647576675780757857578975925†75976†

Angelina County · 41 mg/L · Soft

7590175903759047594175949†7596975980†

Tyler County · 39.7 mg/L · Soft

75936†75938†75942†7597977616†77624†77660†77664

Sabine County · 36.9 mg/L · Soft

75948†75959†75968

Jasper County · 36 mg/L · Soft

75931†75951†75956†7761277615†

La Salle County · 36 mg/L · Soft

78001†78014†78021†

Upshur County · 34.6 mg/L · Soft

75644756457568375755

Newton County · 31.3 mg/L · Soft

75928†75932†75933†75966†75977†77614

San Augustine County · 30.7 mg/L · Soft

75929†75930†75972†

Harrison County · 29 mg/L · Soft

75602756407565075651756597566175670756717567275692†75694

Marion County · 28.2 mg/L · Soft

75657

Hardin County · 20 mg/L · Soft

7737477376775197758577625776567765777659†77663†

Camp County · 19 mg/L · Soft

75451†75686

† 572 ZIP codes are not served by a mapped community water system — most are private-well areas. See well water hardness.

Check any ZIP's utility and hardness →

Source

Groundwater vs surface water

Texas's groundwater measures harder than its surface water — 254 mg/L across 14,259 samples versus 189 across 101,777, about 1.3× harder. Wells draw from groundwater, so well owners in Texas tend to see the harder number — 254 mg/L, very hard. Groundwater readings there run 41.3 to 530 mg/L across the middle 80% of samples. The comparison draws on 6,670 groundwater and 1,898 surface-water monitoring sites; 8,654 readings above 2,000 mg/L were logged but held out of the medians as outliers.

Groundwater (wells)

254 mg/L as CaCO₃ · 14,259 results at 6,670 stations.

Surface water (rivers, lakes)

189 mg/L as CaCO₃ · 101,777 results at 1,898 stations.

Groundwater measures about 1.3× harder than surface water here.

Chemistry

Water chemistry in Texas

Beyond the hardness number, Texas's water carries a fuller chemical signature — here is how its measured parameters compare to national benchmarks.

TDS

294 mg/L · n=12,896

294 mg/L — about 1.3× the national county median of 226, consistent with hard, mineral-rich water.

pH

7.8 pH · n=66,862

pH 7.8 — within the EPA secondary range of 6.5–8.5, on the alkaline side.

Alkalinity

117 mg/L as CaCO3 · n=32,430

117 mg/L — substantial buffering capacity, which resists pH swings.

Calcium : Magnesium

49 : 6.4 mg/L ≈ 7.66 : 1 · n=19,948

Calcium is about 82% of Texas's hardness (49 mg/L Ca to 6.4 mg/L Mg), a little more calcium-rich than the national ~68% calcium share.

Parameter medians may include a small share of quality-control samples; the hardness lane is fully QC-filtered.

Aquifers

Major aquifers under Texas

3 aquifer systems supply much of Texas's measured groundwater.

  • Seymour aquifer — median 759.5 mg/L across 37 samples at 21 sites: very hard.
  • Alluvial aquifers — median 366 mg/L across 256 samples at 189 sites: very hard.
  • Edwards-Trinity aquifer system — median 292 mg/L across 7,173 samples at 1,230 sites: very hard.

Together these systems account for 7,466 measured samples at 1,440 sites. Aquifer medians pool samples across a whole system and can mask local variation — see the national aquifer map for how these compare across states.

Trend

Hardness over time

1930s2020s245

Texas's decade median moved from 245 mg/L in the 1930s to 118 in the 2020s. Over the series, the decade median peaked at 245 mg/L in the 1930s and bottomed at 118 in the 2020s. Decade medians reflect where and what agencies sampled in each era, not just changes in the water itself.

Scale

Where Texas sits on the scale

On the USGS scale, Texas's 200 mg/L is very hard — 11.7 grains per gallon, well above the 180 mg/L very-hard cutoff — among the hardest water measured in the US.

SoftModerately hardHardVery hard60 · 3.5 gpg120 · 7.0 gpg180 · 10.5 gpg200 mg/L — Very hard
Harder than 64% of the 2,977 measured county medians.

At 200 mg/L (11.7 gpg), water-softener owners in Texas typically set their unit to this hardness — settings calculator.

Questions

Frequently asked questions

Is Texas's water hard?
Texas's median hardness is 200 mg/L as CaCO₃, "very hard" on the USGS scale and 1.43× the national county median of 140 mg/L. About 69% of residents in measured counties have hard-or-worse water.
Which county in Texas has the hardest water?
Childress County, with a median of 1600 mg/L as CaCO₃ across 524 measurements.
Is well water harder than city water in Texas?
Groundwater measures harder here — about 1.3× the surface water — so wells tend to run harder (groundwater 254 vs surface water 189 mg/L).
How do I find my exact hardness in Texas?
Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.
Is Texas's water harder than the national average?
Yes. Texas's median of 200 mg/L is 1.43× the national county median of 140 mg/L, and Texas ranks #14 of the 50 states and D.C.

Compare

States with similar hardness

Two states measure closest to Texas's 200 mg/L: Missouri at 196 mg/L and New Mexico at 207 mg/L. Texas measures harder than 74% of states. Browse the full ranking on the statistics page.

More: hardness scale · check your address · national statistics · the national map.

By . Source: USGS/EPA Water Quality Portal — 116,518 Texas measurements. Data last verified . Methodology.

Cite this page: “Texas Water Hardness by County.” Hard Water Map. Retrieved 2026-07-22, https://hardwatermap.com/water-hardness/texas/