Hard Water Map

Arkansas Water Hardness by County

Water in Arkansas has a median hardness of 62 mg/L as CaCO₃ — "moderately hard" on the USGS scale — based on 96,699 measurements at 6,139 monitoring stations. Fulton County has the state's hardest measured water (220 mg/L); Perry County the softest (12). Rank: #33 of the 50 states and D.C.

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

Of Arkansas's 75 measured counties, 3 very hard, 13 hard, 24 moderately hard, and 35 soft. The hardest are Fulton County (220 mg/L), Sharp County (205), and Lawrence County (195). Perry County is the softest at 12 mg/L (soft).

About 12% of Arkansas's roughly 3 million residents in counties with gate-passing hardness data live where tap water is hard or worse.

Statewide, Arkansas's median works out to 3.6 grains per gallon and ranks #33 of the 50 states and D.C. Across 96,699 measurements at 6,139 stations — 42,995 of them since 2000 — the middle 80% of readings fall between 12.3 and 193 mg/L. The public record runs from 1928 to 2026.

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

Download the Arkansas water hardness map (PNG) — Water hardness by county in Arkansas: 75 counties mapped from USGS/EPA data, statewide median 62 mg/L (moderately hard); darker counties have harder water.

By county

Water hardness by county

The table lists all 75 measured Arkansas counties, hardest first. Their medians span 220 mg/L in Fulton County to 12 in Perry County — a 18.3× range.

County water hardness, hardest first — median mg/L as CaCO₃.
CountyMedianBandResultsSitesNewest
Fulton County220Very hard1,084412026
Sharp County205Very hard863642026
Lawrence County195Very hard1,233552026
Boone County173Hard1,1371102026
Crittenden County170Hard2991052026
Mississippi County170Hard4451182026
Poinsett County170Hard563512026
Randolph County170Hard1,817442026
Baxter County160Hard2,436342026
Izard County149Hard557252026
Jackson County140Hard1,163492026
Little River County140Hard1,356412025
Marion County138Hard1,574482026
Stone County137.5Hard1,004342026
Independence County137Hard753502025
Chicot County120Hard307892026
Carroll County118Moderately hard2,854652026
Sebastian County118Moderately hard1,417522026
Benton County110Moderately hard3,7791582026
Prairie County110Moderately hard1,055832026
Cross County108Moderately hard593432026
Searcy County108Moderately hard1,020512026
Clay County103Moderately hard623412026
Arkansas County100Moderately hard1,4161272026
Lee County98Moderately hard499452026
Monroe County98Moderately hard1,7901552026
Phillips County95.8Moderately hard142322026
St. Francis County95Moderately hard1,019622026
Franklin County89.3Moderately hard788582026
Miller County86Moderately hard1,587802025
Madison County84.7Moderately hard1,246292026
Washington County84Moderately hard4,402852026
Newton County83.8Moderately hard503452023
Desha County80.5Moderately hard8091542026
Lonoke County78.1Moderately hard6111902026
Craighead County75Moderately hard1,064822026
Jefferson County75Moderately hard1,9932212026
Conway County74.1Moderately hard8481122026
Union County66Moderately hard4,4341412026
Pulaski County62.5Moderately hard4,9402032025
Pope County57.7Soft3,4771362026
Woodruff County55.4Soft1,086902026
Saline County51.3Soft2,158592025
Lincoln County45.2Soft5841422026
Greene County45Soft87262026
Faulkner County40Soft1,2651302026
Dallas County39.9Soft752362026
Grant County38Soft1,118552025
Ashley County30Soft769532026
Lafayette County30Soft732352025
Drew County29.4Soft5091322025
Cleveland County28Soft555202025
Hempstead County28Soft6041102025
Bradley County26Soft717762026
Clark County26Soft1,898862025
Hot Spring County24.4Soft1,9181102025
Garland County24Soft1,0721042025
Nevada County24Soft679632023
Logan County23Soft1,129722026
Ouachita County22.9Soft1,1591552025
Montgomery County22Soft1,207312026
Columbia County20.8Soft598692025
Scott County19.9Soft1,320352026
Johnson County19.1Soft356562024
Crawford County18Soft7841482026
White County18Soft893692026
Yell County17.7Soft1,9212252026
Cleburne County17Soft1,306492024
Sevier County17Soft2,634762026
Howard County16Soft2,3461182026
Pike County16Soft957532025
Polk County14.2Soft1,234382026
Van Buren County13.6Soft1,2961082026
Calhoun County12Soft424732026
Perry County12Soft1,132292026

ZIP codes

ZIP codes in Arkansas

The ZIP codes below are grouped by the Arkansas 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.

Fulton County · 220 mg/L · Very hard

72515†72520†72531†72538†72539†72554†72576†72578†72583†

Sharp County · 205 mg/L · Very hard

72482†72513†725217252972532†72542†72569

Lawrence County · 195 mg/L · Very hard

72410724157243372440†72445724577245872466†7246972476†72572

Boone County · 173 mg/L · Hard

72601726157263072644†72662†

Crittenden County · 170 mg/L · Hard

7230172325†7232772331723327233972348†723647237672384†

Mississippi County · 170 mg/L · Hard

72313†7231572329†72330†72350†723517235872370†7239172395†72426724287243872442

Poinsett County · 170 mg/L · Hard

7235472365†72377†72386†724297243272472†72479†

Randolph County · 170 mg/L · Hard

72413†7243472444†7244972455†72459†72460†72462†72478†

Baxter County · 160 mg/L · Hard

72519†72537†72544†72617†72623†72626†72635†72642726517265372658†

Izard County · 149 mg/L · Hard

7251272517†7252872536†725407255672561†7256572566†7257372577†7258472585†72587†

Jackson County · 140 mg/L · Hard

72005†7201472020720757211272169†7243172471†72473†

Little River County · 140 mg/L · Hard

71820†718227183671853†7186571866†

Marion County · 138 mg/L · Hard

726197263372634†7266172668†72672†72677†7268272687

Stone County · 137.5 mg/L · Hard

72051725337255572560725677266372680†

Independence County · 137 mg/L · Hard

7216572501725227252472526725277253472550725537256272564†7256872571†72579

Chicot County · 120 mg/L · Hard

71640†71653†71663†

Carroll County · 118 mg/L · Moderately hard

72611†7261672631†726327263872660†

Sebastian County · 118 mg/L · Moderately hard

72901729037290472905†72908729167292372936729377293872940729417294472945

Benton County · 110 mg/L · Moderately hard

7271272713†727147271572718727197272272732727347273672739727457274772751727567275872761†72768†

Prairie County · 110 mg/L · Moderately hard

7201772040†720417206472066†72170

Cross County · 108 mg/L · Moderately hard

7232472347†72373†7238772396

Searcy County · 108 mg/L · Moderately hard

7263672639†72645†72650†7266972675†72679†

Clay County · 103 mg/L · Moderately hard

72422†724247243072435†7244172453†7245472456724617246472470

Arkansas County · 100 mg/L · Moderately hard

7200372026†720387204272048†7205572073721407216072166†

Lee County · 98 mg/L · Moderately hard

723117232072341†7235272360†72368†

Monroe County · 98 mg/L · Moderately hard

7202172029†72069†7210872134†

Phillips County · 95.8 mg/L · Moderately hard

72333†72342†72353†723557236672367†72369†72374†72383†72389†72390†

St. Francis County · 95 mg/L · Moderately hard

7232272326†7233572340†72346†723597237272392†72394

Franklin County · 89.3 mg/L · Moderately hard

7282172928†72930729337294772949

Miller County · 86 mg/L · Moderately hard

71834†71837†71839†71854†

Madison County · 84.7 mg/L · Moderately hard

7272172727†727387274072742†72752†72760†7277372776

Washington County · 84 mg/L · Moderately hard

7270172703†727047271772729727307274472749727537276272764727697277472959†

Newton County · 83.8 mg/L · Moderately hard

72624726287264072641†72648†72655†7266672670†7268372685†72856†

Desha County · 80.5 mg/L · Moderately hard

71630†71654†71662†71666†71670†71674†72328†72379

Lonoke County · 78.1 mg/L · Moderately hard

72007720237202472046720727208372086†7214272176

Craighead County · 75 mg/L · Moderately hard

7240172404†7240572411†72414†72416†724177241972421724277243772447†72467

Jefferson County · 75 mg/L · Moderately hard

71601†7160271603†7165972004†72079721327213372152†72168†7217572182†

Conway County · 74.1 mg/L · Moderately hard

7202772030†72063721077211072127†72156†72157

Union County · 66 mg/L · Moderately hard

717247173071747†71749†71758†7175971762†71765†

Pulaski County · 62.5 mg/L · Moderately hard

7205372076720997211372114721167211772118721197212072135721807218372199722017220272204722057220672207722097221072211722127222372227

Pope County · 57.7 mg/L · Soft

72686†7280172802†72823†72837†72843†72847†72858†

Woodruff County · 55.4 mg/L · Soft

72006†720367205972074†72101†72123

Saline County · 51.3 mg/L · Soft

720027201172015†72019†7202272065†720877210372122†72167†

Lincoln County · 45.2 mg/L · Soft

71639†71643†71644†7166771678

Greene County · 45 mg/L · Soft

724127242572436†7244372450

Faulkner County · 40 mg/L · Soft

72032720347203572039†72047†720587206172106721117217372181

Dallas County · 39.9 mg/L · Soft

71725†71742†717487176372084

Grant County · 38 mg/L · Soft

72057721287212972150

Ashley County · 30 mg/L · Soft

71635†71642†71646†71658†71661†71676†

Lafayette County · 30 mg/L · Soft

71826†71827†71845†71860†71861

Drew County · 29.4 mg/L · Soft

71638†7165571675†71677†

Cleveland County · 28 mg/L · Soft

716527166071665†

Hempstead County · 28 mg/L · Soft

718017182571838†7184771855†71859†71862†

Bradley County · 26 mg/L · Soft

71631716477165171671

Clark County · 26 mg/L · Soft

717217172871743†71772719217192371962†7199871999

Hot Spring County · 24.4 mg/L · Soft

7192971941†71942†72104

Garland County · 24 mg/L · Soft

71901†71909719137193371949719567196471968

Nevada County · 24 mg/L · Soft

71722†71835†718577185871864

Logan County · 23 mg/L · Soft

7282672835†72851†72855†72863†72865729277294372951

Ouachita County · 22.9 mg/L · Soft

71701717207172671751†71764†

Montgomery County · 22 mg/L · Soft

71935†7195771960†71961†71965†71969†71970†

Columbia County · 20.8 mg/L · Soft

71740†71752†7175371770

Scott County · 19.9 mg/L · Soft

72841†72926†7295072958

Johnson County · 19.1 mg/L · Soft

728307283272839†7284072845†728467285272854†

Crawford County · 18 mg/L · Soft

729217293272934†7293572946†72948†729527295572956

White County · 18 mg/L · Soft

72010†72012720457205272060†720687208172082720857210272121†7213672137†721397214372178

Yell County · 17.7 mg/L · Soft

7282472827†728287282972833†7283472838†72842†72853†72857†72860

Cleburne County · 17 mg/L · Soft

72044†7206772130†72131†72179†725237253072543†72546†72581

Sevier County · 17 mg/L · Soft

7182371832718417184271846

Howard County · 16 mg/L · Soft

71831†71833†71851†7185271971

Pike County · 16 mg/L · Soft

71922†7194071943†71950†71952†7195871959†

Polk County · 14.2 mg/L · Soft

71937†71944719457195371972†71973

Van Buren County · 13.6 mg/L · Soft

72013720287203172080†72088721417215372629†

Calhoun County · 12 mg/L · Soft

717447174571766†

Perry County · 12 mg/L · Soft

72001†72016†72025†72070†7212572126

† 259 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

Arkansas's groundwater measures harder than its surface water — 150 mg/L across 5,656 samples versus 60 across 90,927, about 2.5× harder. Wells draw from groundwater, so well owners in Arkansas tend to see the harder number — 150 mg/L, hard. Groundwater readings there run 12 to 380 mg/L across the middle 80% of samples. The comparison draws on 4,176 groundwater and 1,958 surface-water monitoring sites; 294 readings above 2,000 mg/L were logged but held out of the medians as outliers.

Groundwater (wells)

150 mg/L as CaCO₃ · 5,656 results at 4,176 stations.

Surface water (rivers, lakes)

60 mg/L as CaCO₃ · 90,927 results at 1,958 stations.

Groundwater measures about 2.5× harder than surface water here.

Chemistry

Water chemistry in Arkansas

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

TDS

104 mg/L · n=41,545

104 mg/L — below the national county median of 226.

pH

7.2 pH · n=26,162

pH 7.2 — within the EPA secondary range of 6.5–8.5, on the alkaline side.

Alkalinity

53 mg/L as CaCO3 · n=58,903

53 mg/L — modest buffering capacity.

Calcium : Magnesium

12.2 : 2.5 mg/L ≈ 4.88 : 1 · n=65,736

Calcium is about 75% of Arkansas's hardness (12.2 mg/L Ca to 2.5 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 Arkansas

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

  • Mississippi River Valley alluvial aquifer — median 240 mg/L across 1,455 samples at 1,176 sites: very hard.
  • Alluvial aquifers — median 210 mg/L across 936 samples at 803 sites: very hard.
  • Ozark Plateaus aquifer system — median 182 mg/L across 465 samples at 263 sites: very hard.

Together these systems account for 2,856 measured samples at 2,242 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

1940s2020s120

Arkansas's decade median moved from 94 mg/L in the 1940s to 40.3 in the 2020s. Over the series, the decade median peaked at 120 mg/L in the 1950s and bottomed at 40.3 in the 2020s. Decade medians reflect where and what agencies sampled in each era, not just changes in the water itself.

Scale

Where Arkansas sits on the scale

On the USGS scale, Arkansas's 62 mg/L is moderately hard — 3.6 grains per gallon, between the 60 and 120 mg/L soft and hard cutoffs.

SoftModerately hardHardVery hard60 · 3.5 gpg120 · 7.0 gpg180 · 10.5 gpg62 mg/L — Moderately hard
Harder than 29% of the 2,977 measured county medians.

Questions

Frequently asked questions

Is Arkansas's water hard?
Arkansas's median hardness is 62 mg/L as CaCO₃, "moderately hard" on the USGS scale and below the national county median of 140 mg/L.
Which county in Arkansas has the hardest water?
Fulton County, with a median of 220 mg/L as CaCO₃ across 1,084 measurements.
Is well water harder than city water in Arkansas?
Groundwater measures harder here — about 2.5× the surface water — so wells tend to run harder (groundwater 150 vs surface water 60 mg/L).
How do I find my exact hardness in Arkansas?
Search your ZIP on the lookup tool, read your utility's Consumer Confidence Report, or test at home with a kit.
Is Arkansas's water harder than the national average?
No. Arkansas's median of 62 mg/L is below the national county median of 140 mg/L; it ranks #33 of the 50 states and D.C.

Compare

States with similar hardness

Two states measure closest to Arkansas's 62 mg/L: Delaware at 63.9 mg/L and New Jersey at 59.9 mg/L. Arkansas measures harder than 36% 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 — 96,699 Arkansas measurements. Data last verified . Methodology.

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