Private Well Water Testing in Texas
County-by-county USGS area-risk estimates for private wells across Texas โ arsenic exceedance probability and private-well population โ plus how to test your own well at a Texas-certified laboratory.
Texas private-well risk summary
Counties covered
253
Texas counties with modeled risk data.
People on private wells
area estimate1,647,623
estimated across covered Texas counties.
Average arsenic risk
area estimate7%
average modeled chance a well exceeds 10 ยตg/L arsenic across covered counties.
Texas counties
- Harris County3% arsenic exceedance (area estimate)99,003 people on private wells
- Brazoria County4% arsenic exceedance (area estimate)55,657 people on private wells
- Montgomery County2% arsenic exceedance (area estimate)47,773 people on private wells
- Fort Bend County2% arsenic exceedance (area estimate)36,772 people on private wells
- Parker County3% arsenic exceedance (area estimate)35,289 people on private wells
- Lubbock County35% arsenic exceedance (area estimate)31,534 people on private wells
- Ector County29% arsenic exceedance (area estimate)30,535 people on private wells
- Liberty County2% arsenic exceedance (area estimate)30,253 people on private wells
- Orange County1% arsenic exceedance (area estimate)29,749 people on private wells
- Wise County3% arsenic exceedance (area estimate)28,830 people on private wells
- Bexar County2% arsenic exceedance (area estimate)26,931 people on private wells
- Comal County1% arsenic exceedance (area estimate)24,255 people on private wells
- Midland County20% arsenic exceedance (area estimate)24,249 people on private wells
- Bowie County1% arsenic exceedance (area estimate)20,927 people on private wells
- Hays County1% arsenic exceedance (area estimate)20,796 people on private wells
- Tarrant County4% arsenic exceedance (area estimate)19,189 people on private wells
- Denton County2% arsenic exceedance (area estimate)18,258 people on private wells
- Wharton County4% arsenic exceedance (area estimate)17,786 people on private wells
- Victoria County5% arsenic exceedance (area estimate)17,574 people on private wells
- El Paso County21% arsenic exceedance (area estimate)16,895 people on private wells
- Waller County2% arsenic exceedance (area estimate)16,459 people on private wells
- Hardin County1% arsenic exceedance (area estimate)16,317 people on private wells
- Jasper County1% arsenic exceedance (area estimate)15,917 people on private wells
- Cass County1% arsenic exceedance (area estimate)15,914 people on private wells
- Williamson County1% arsenic exceedance (area estimate)15,764 people on private wells
- Erath County2% arsenic exceedance (area estimate)15,330 people on private wells
- Kendall County1% arsenic exceedance (area estimate)14,920 people on private wells
- Travis County2% arsenic exceedance (area estimate)14,737 people on private wells
- Austin County2% arsenic exceedance (area estimate)14,656 people on private wells
- Washington County2% arsenic exceedance (area estimate)14,649 people on private wells
- Galveston County6% arsenic exceedance (area estimate)14,174 people on private wells
- Burnet County2% arsenic exceedance (area estimate)14,138 people on private wells
- Grimes County2% arsenic exceedance (area estimate)14,116 people on private wells
- Randall County3% arsenic exceedance (area estimate)14,013 people on private wells
- Bandera County1% arsenic exceedance (area estimate)13,992 people on private wells
- Bee County32% arsenic exceedance (area estimate)13,585 people on private wells
- Van Zandt County1% arsenic exceedance (area estimate)12,712 people on private wells
- Hidalgo County35% arsenic exceedance (area estimate)12,607 people on private wells
- Harrison County1% arsenic exceedance (area estimate)12,571 people on private wells
- Walker County2% arsenic exceedance (area estimate)12,549 people on private wells
- Gillespie County2% arsenic exceedance (area estimate)12,218 people on private wells
- Atascosa County2% arsenic exceedance (area estimate)12,127 people on private wells
- Jim Wells County35% arsenic exceedance (area estimate)12,099 people on private wells
- Cameron County7% arsenic exceedance (area estimate)11,878 people on private wells
- Kerr County1% arsenic exceedance (area estimate)11,872 people on private wells
- Potter County6% arsenic exceedance (area estimate)11,588 people on private wells
- Henderson County2% arsenic exceedance (area estimate)11,404 people on private wells
- Smith County2% arsenic exceedance (area estimate)11,079 people on private wells
- Tom Green County3% arsenic exceedance (area estimate)10,478 people on private wells
- Fayette County3% arsenic exceedance (area estimate)10,143 people on private wells
- Lavaca County4% arsenic exceedance (area estimate)10,133 people on private wells
- Medina County3% arsenic exceedance (area estimate)9,947 people on private wells
- San Jacinto County2% arsenic exceedance (area estimate)9,915 people on private wells
- Colorado County4% arsenic exceedance (area estimate)9,822 people on private wells
- Guadalupe County3% arsenic exceedance (area estimate)9,482 people on private wells
- Johnson County3% arsenic exceedance (area estimate)9,310 people on private wells
- Hood County2% arsenic exceedance (area estimate)9,178 people on private wells
- Grayson County2% arsenic exceedance (area estimate)9,066 people on private wells
- Polk County2% arsenic exceedance (area estimate)8,932 people on private wells
- Brazos County2% arsenic exceedance (area estimate)8,791 people on private wells
- Chambers County4% arsenic exceedance (area estimate)8,718 people on private wells
- Matagorda County4% arsenic exceedance (area estimate)8,488 people on private wells
- Upshur County2% arsenic exceedance (area estimate)8,419 people on private wells
- Wilson County3% arsenic exceedance (area estimate)8,291 people on private wells
- San Patricio County13% arsenic exceedance (area estimate)7,779 people on private wells
- Nueces County12% arsenic exceedance (area estimate)7,607 people on private wells
- Tyler County1% arsenic exceedance (area estimate)7,571 people on private wells
- Montague County5% arsenic exceedance (area estimate)7,516 people on private wells
- Cooke County2% arsenic exceedance (area estimate)7,506 people on private wells
- Newton County1% arsenic exceedance (area estimate)7,469 people on private wells
- DeWitt County6% arsenic exceedance (area estimate)7,458 people on private wells
- Dallas County7% arsenic exceedance (area estimate)7,329 people on private wells
- Gaines County61% arsenic exceedance (area estimate)7,197 people on private wells
- Hale County8% arsenic exceedance (area estimate)7,015 people on private wells
- Bastrop County2% arsenic exceedance (area estimate)6,654 people on private wells
- Panola County2% arsenic exceedance (area estimate)6,634 people on private wells
- Bell County2% arsenic exceedance (area estimate)6,490 people on private wells
- Rusk County1% arsenic exceedance (area estimate)6,455 people on private wells
- Titus County2% arsenic exceedance (area estimate)6,424 people on private wells
- Comanche County4% arsenic exceedance (area estimate)6,289 people on private wells
- Frio County3% arsenic exceedance (area estimate)6,140 people on private wells
- Blanco County1% arsenic exceedance (area estimate)6,121 people on private wells
- Leon County2% arsenic exceedance (area estimate)5,869 people on private wells
- Angelina County1% arsenic exceedance (area estimate)5,768 people on private wells
- Callahan County2% arsenic exceedance (area estimate)5,737 people on private wells
- Madison County2% arsenic exceedance (area estimate)5,560 people on private wells
- Wood County2% arsenic exceedance (area estimate)5,558 people on private wells
- Cherokee County1% arsenic exceedance (area estimate)5,547 people on private wells
- Shelby County2% arsenic exceedance (area estimate)5,526 people on private wells
- Hockley County39% arsenic exceedance (area estimate)5,390 people on private wells
- Anderson County1% arsenic exceedance (area estimate)5,344 people on private wells
- Uvalde County2% arsenic exceedance (area estimate)5,237 people on private wells
- Somervell County2% arsenic exceedance (area estimate)5,231 people on private wells
- Scurry County17% arsenic exceedance (area estimate)5,031 people on private wells
- Jefferson County2% arsenic exceedance (area estimate)4,990 people on private wells
- Jackson County4% arsenic exceedance (area estimate)4,936 people on private wells
- Burleson County2% arsenic exceedance (area estimate)4,904 people on private wells
- Jack County9% arsenic exceedance (area estimate)4,836 people on private wells
- Live Oak County13% arsenic exceedance (area estimate)4,816 people on private wells
- Marion County1% arsenic exceedance (area estimate)4,761 people on private wells
- Goliad County16% arsenic exceedance (area estimate)4,755 people on private wells
- Howard County12% arsenic exceedance (area estimate)4,581 people on private wells
- Llano County4% arsenic exceedance (area estimate)4,565 people on private wells
- Nacogdoches County2% arsenic exceedance (area estimate)4,378 people on private wells
- Coryell County1% arsenic exceedance (area estimate)4,357 people on private wells
- Karnes County7% arsenic exceedance (area estimate)4,169 people on private wells
- Morris County2% arsenic exceedance (area estimate)4,104 people on private wells
- Ellis County2% arsenic exceedance (area estimate)4,038 people on private wells
- Gonzales County2% arsenic exceedance (area estimate)4,026 people on private wells
- San Augustine County1% arsenic exceedance (area estimate)3,936 people on private wells
- Andrews County65% arsenic exceedance (area estimate)3,905 people on private wells
- Caldwell County2% arsenic exceedance (area estimate)3,860 people on private wells
- Bosque County1% arsenic exceedance (area estimate)3,851 people on private wells
- Hamilton County1% arsenic exceedance (area estimate)3,840 people on private wells
- Limestone County2% arsenic exceedance (area estimate)3,745 people on private wells
- Robertson County2% arsenic exceedance (area estimate)3,643 people on private wells
- Aransas County10% arsenic exceedance (area estimate)3,641 people on private wells
- Palo Pinto County8% arsenic exceedance (area estimate)3,589 people on private wells
- Lampasas County2% arsenic exceedance (area estimate)3,521 people on private wells
- McLennan County2% arsenic exceedance (area estimate)3,476 people on private wells
- Deaf Smith County5% arsenic exceedance (area estimate)3,463 people on private wells
- Houston County2% arsenic exceedance (area estimate)3,407 people on private wells
- Calhoun County8% arsenic exceedance (area estimate)3,306 people on private wells
- Pecos County4% arsenic exceedance (area estimate)3,301 people on private wells
- Gregg County2% arsenic exceedance (area estimate)3,297 people on private wells
- Camp County2% arsenic exceedance (area estimate)3,218 people on private wells
- Kaufman County2% arsenic exceedance (area estimate)3,142 people on private wells
- Milam County1% arsenic exceedance (area estimate)3,116 people on private wells
- Sabine County1% arsenic exceedance (area estimate)3,039 people on private wells
- Fannin County2% arsenic exceedance (area estimate)3,037 people on private wells
- Eastland County6% arsenic exceedance (area estimate)3,013 people on private wells
- Lee County2% arsenic exceedance (area estimate)2,945 people on private wells
- Gray County3% arsenic exceedance (area estimate)2,908 people on private wells
- Dawson County72% arsenic exceedance (area estimate)2,847 people on private wells
- Swisher County3% arsenic exceedance (area estimate)2,792 people on private wells
- Duval County34% arsenic exceedance (area estimate)2,779 people on private wells
- Mills County3% arsenic exceedance (area estimate)2,744 people on private wells
- Hunt County3% arsenic exceedance (area estimate)2,716 people on private wells
- Parmer County14% arsenic exceedance (area estimate)2,713 people on private wells
- Kleberg County14% arsenic exceedance (area estimate)2,680 people on private wells
- Lynn County32% arsenic exceedance (area estimate)2,534 people on private wells
- Val Verde County2% arsenic exceedance (area estimate)2,518 people on private wells
- Terry County61% arsenic exceedance (area estimate)2,511 people on private wells
- Clay County12% arsenic exceedance (area estimate)2,469 people on private wells
- Dimmit County3% arsenic exceedance (area estimate)2,466 people on private wells
- Taylor County3% arsenic exceedance (area estimate)2,440 people on private wells
- Lamar County2% arsenic exceedance (area estimate)2,391 people on private wells
- Freestone County2% arsenic exceedance (area estimate)2,331 people on private wells
- Brown County2% arsenic exceedance (area estimate)2,311 people on private wells
- Lamb County22% arsenic exceedance (area estimate)2,298 people on private wells
- Mason County3% arsenic exceedance (area estimate)2,296 people on private wells
- Martin County49% arsenic exceedance (area estimate)2,204 people on private wells
- Collin County3% arsenic exceedance (area estimate)2,200 people on private wells
- Hopkins County2% arsenic exceedance (area estimate)2,186 people on private wells
- Webb County8% arsenic exceedance (area estimate)2,141 people on private wells
- Red River County2% arsenic exceedance (area estimate)2,116 people on private wells
- Jim Hogg County34% arsenic exceedance (area estimate)2,092 people on private wells
- San Saba County4% arsenic exceedance (area estimate)2,090 people on private wells
- Yoakum County51% arsenic exceedance (area estimate)2,014 people on private wells
- Hill County3% arsenic exceedance (area estimate)2,013 people on private wells
- Real County1% arsenic exceedance (area estimate)1,992 people on private wells
- Castro County5% arsenic exceedance (area estimate)1,978 people on private wells
- Refugio County7% arsenic exceedance (area estimate)1,939 people on private wells
- Kimble County2% arsenic exceedance (area estimate)1,921 people on private wells
- Bailey County17% arsenic exceedance (area estimate)1,894 people on private wells
- Ward County11% arsenic exceedance (area estimate)1,894 people on private wells
- Starr County37% arsenic exceedance (area estimate)1,795 people on private wells
- Hartley County8% arsenic exceedance (area estimate)1,721 people on private wells
- Young County9% arsenic exceedance (area estimate)1,698 people on private wells
- Brewster County6% arsenic exceedance (area estimate)1,688 people on private wells
- Brooks County17% arsenic exceedance (area estimate)1,681 people on private wells
- Jones County8% arsenic exceedance (area estimate)1,584 people on private wells
- Falls County2% arsenic exceedance (area estimate)1,551 people on private wells
- Wilbarger County5% arsenic exceedance (area estimate)1,540 people on private wells
- Maverick County4% arsenic exceedance (area estimate)1,428 people on private wells
- Navarro County2% arsenic exceedance (area estimate)1,343 people on private wells
- Moore County4% arsenic exceedance (area estimate)1,319 people on private wells
- Floyd County13% arsenic exceedance (area estimate)1,308 people on private wells
- Carson County3% arsenic exceedance (area estimate)1,299 people on private wells
- La Salle County3% arsenic exceedance (area estimate)1,259 people on private wells
- Wheeler County3% arsenic exceedance (area estimate)1,235 people on private wells
- Trinity County2% arsenic exceedance (area estimate)1,210 people on private wells
- Ochiltree County4% arsenic exceedance (area estimate)1,191 people on private wells
- Concho County2% arsenic exceedance (area estimate)1,179 people on private wells
- Runnels County3% arsenic exceedance (area estimate)1,158 people on private wells
- Glasscock County5% arsenic exceedance (area estimate)1,156 people on private wells
- Upton County4% arsenic exceedance (area estimate)1,124 people on private wells
- Mitchell County9% arsenic exceedance (area estimate)1,111 people on private wells
- Zavala County3% arsenic exceedance (area estimate)1,088 people on private wells
- McCulloch County3% arsenic exceedance (area estimate)1,086 people on private wells
- Nolan County6% arsenic exceedance (area estimate)1,059 people on private wells
- Schleicher County2% arsenic exceedance (area estimate)1,017 people on private wells
- Wichita County14% arsenic exceedance (area estimate)1,013 people on private wells
- Jeff Davis County14% arsenic exceedance (area estimate)954 people on private wells
- Irion County2% arsenic exceedance (area estimate)925 people on private wells
- Hansford County5% arsenic exceedance (area estimate)917 people on private wells
- Hemphill County3% arsenic exceedance (area estimate)904 people on private wells
- Haskell County6% arsenic exceedance (area estimate)887 people on private wells
- Presidio County20% arsenic exceedance (area estimate)885 people on private wells
- Dallam County12% arsenic exceedance (area estimate)881 people on private wells
- Hutchinson County3% arsenic exceedance (area estimate)878 people on private wells
- Rains County1% arsenic exceedance (area estimate)868 people on private wells
- Crosby County14% arsenic exceedance (area estimate)856 people on private wells
- Franklin County2% arsenic exceedance (area estimate)840 people on private wells
- Donley County4% arsenic exceedance (area estimate)819 people on private wells
- Hudspeth County13% arsenic exceedance (area estimate)806 people on private wells
- Coke County3% arsenic exceedance (area estimate)773 people on private wells
- Garza County12% arsenic exceedance (area estimate)772 people on private wells
- Sutton County2% arsenic exceedance (area estimate)722 people on private wells
- Menard County2% arsenic exceedance (area estimate)702 people on private wells
- Edwards County2% arsenic exceedance (area estimate)679 people on private wells
- Sherman County4% arsenic exceedance (area estimate)667 people on private wells
- Lipscomb County3% arsenic exceedance (area estimate)663 people on private wells
- Willacy County14% arsenic exceedance (area estimate)640 people on private wells
- Armstrong County4% arsenic exceedance (area estimate)625 people on private wells
- Kinney County2% arsenic exceedance (area estimate)625 people on private wells
- Cochran County27% arsenic exceedance (area estimate)565 people on private wells
- Knox County3% arsenic exceedance (area estimate)556 people on private wells
- Baylor County6% arsenic exceedance (area estimate)540 people on private wells
- Dickens County3% arsenic exceedance (area estimate)539 people on private wells
- Briscoe County5% arsenic exceedance (area estimate)460 people on private wells
- Collingsworth County3% arsenic exceedance (area estimate)447 people on private wells
- Crockett County2% arsenic exceedance (area estimate)421 people on private wells
- Coleman County2% arsenic exceedance (area estimate)407 people on private wells
- Reagan County3% arsenic exceedance (area estimate)398 people on private wells
- Reeves County7% arsenic exceedance (area estimate)398 people on private wells
- Oldham County8% arsenic exceedance (area estimate)368 people on private wells
- Hardeman County3% arsenic exceedance (area estimate)364 people on private wells
- Roberts County3% arsenic exceedance (area estimate)354 people on private wells
- Sterling County3% arsenic exceedance (area estimate)344 people on private wells
- Winkler County21% arsenic exceedance (area estimate)343 people on private wells
- Borden County18% arsenic exceedance (area estimate)340 people on private wells
- Kent County6% arsenic exceedance (area estimate)323 people on private wells
- Archer County15% arsenic exceedance (area estimate)313 people on private wells
- McMullen County2% arsenic exceedance (area estimate)303 people on private wells
- Motley County3% arsenic exceedance (area estimate)287 people on private wells
- Stonewall County4% arsenic exceedance (area estimate)220 people on private wells
- Crane County8% arsenic exceedance (area estimate)213 people on private wells
- Zapata County12% arsenic exceedance (area estimate)212 people on private wells
- Terrell County3% arsenic exceedance (area estimate)207 people on private wells
- Stephens County8% arsenic exceedance (area estimate)206 people on private wells
- Kenedy County9% arsenic exceedance (area estimate)196 people on private wells
- Culberson County6% arsenic exceedance (area estimate)175 people on private wells
- Fisher County7% arsenic exceedance (area estimate)152 people on private wells
- Cottle County3% arsenic exceedance (area estimate)126 people on private wells
- Foard County3% arsenic exceedance (area estimate)117 people on private wells
- Childress County3% arsenic exceedance (area estimate)102 people on private wells
- Hall County3% arsenic exceedance (area estimate)98 people on private wells
- Delta County2% arsenic exceedance (area estimate)75 people on private wells
- Rockwall County5% arsenic exceedance (area estimate)57 people on private wells
- Throckmorton County3% arsenic exceedance (area estimate)53 people on private wells
- Loving County9% arsenic exceedance (area estimate)52 people on private wells
- Shackelford County2% arsenic exceedance (area estimate)33 people on private wells
Find a Texas-certified testing lab
Get your well tested at a Texas-certified laboratory. We list certification programs by state.
These figures are USGS area estimates: statistical groundwater models describing how likely elevated contaminant levels are across a county. They are not designed to predict the concentration in any single well. Only testing your own well reveals its water quality.
By TapWaterData Editorial
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