Maps

Where contaminants show up in U.S. tap water

PFAS

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Systems with a PFAS reading above an EPA limit (UCMR5, 2023–2025).

Alaska: 4 systems above an EPA PFAS limit of 405 Alabama: 77 systems above an EPA PFAS limit of 545 Arkansas: 1 systems above an EPA PFAS limit of 666 Arizona: 24 systems above an EPA PFAS limit of 954 California: 161 systems above an EPA PFAS limit of 3,071 Colorado: 13 systems above an EPA PFAS limit of 1,113 Connecticut: 37 systems above an EPA PFAS limit of 504 District of Columbia: 0 systems above an EPA PFAS limit of 12 Delaware: 14 systems above an EPA PFAS limit of 209 Florida: 152 systems above an EPA PFAS limit of 1,516 Georgia: 42 systems above an EPA PFAS limit of 1,718 Hawaii: 0 systems above an EPA PFAS limit of 117 Iowa: 8 systems above an EPA PFAS limit of 1,078 Idaho: 3 systems above an EPA PFAS limit of 774 Illinois: 27 systems above an EPA PFAS limit of 1,785 Indiana: 19 systems above an EPA PFAS limit of 718 Kansas: 5 systems above an EPA PFAS limit of 856 Kentucky: 33 systems above an EPA PFAS limit of 375 Louisiana: 7 systems above an EPA PFAS limit of 819 Massachusetts: 106 systems above an EPA PFAS limit of 559 Maryland: 14 systems above an EPA PFAS limit of 467 Maine: 5 systems above an EPA PFAS limit of 359 Michigan: 8 systems above an EPA PFAS limit of 1,429 Minnesota: 17 systems above an EPA PFAS limit of 995 Missouri: 11 systems above an EPA PFAS limit of 1,679 Mississippi: 7 systems above an EPA PFAS limit of 990 Montana: 2 systems above an EPA PFAS limit of 813 North Carolina: 111 systems above an EPA PFAS limit of 1,963 North Dakota: 0 systems above an EPA PFAS limit of 318 Nebraska: 4 systems above an EPA PFAS limit of 594 New Hampshire: 15 systems above an EPA PFAS limit of 677 New Jersey: 151 systems above an EPA PFAS limit of 620 New Mexico: 5 systems above an EPA PFAS limit of 592 Nevada: 3 systems above an EPA PFAS limit of 232 New York: 50 systems above an EPA PFAS limit of 2,202 Ohio: 57 systems above an EPA PFAS limit of 1,130 Oklahoma: 13 systems above an EPA PFAS limit of 884 Oregon: 10 systems above an EPA PFAS limit of 941 Pennsylvania: 109 systems above an EPA PFAS limit of 1,782 Rhode Island: 9 systems above an EPA PFAS limit of 93 South Carolina: 69 systems above an EPA PFAS limit of 557 South Dakota: 1 systems above an EPA PFAS limit of 513 Tennessee: 38 systems above an EPA PFAS limit of 453 Texas: 103 systems above an EPA PFAS limit of 4,617 Utah: 4 systems above an EPA PFAS limit of 560 Virginia: 18 systems above an EPA PFAS limit of 1,052 Vermont: 1 systems above an EPA PFAS limit of 377 Washington: 34 systems above an EPA PFAS limit of 2,403 Wisconsin: 22 systems above an EPA PFAS limit of 977 West Virginia: 20 systems above an EPA PFAS limit of 430 Wyoming: 2 systems above an EPA PFAS limit of 317
1,673 systems above an EPA PFAS limit

Lead

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Systems with a Lead & Copper Rule action-level violation.

Alaska: 24 systems with lead action-level violations of 405 Alabama: 6 systems with lead action-level violations of 545 Arkansas: 53 systems with lead action-level violations of 666 Arizona: 20 systems with lead action-level violations of 954 California: 34 systems with lead action-level violations of 3,071 Colorado: 72 systems with lead action-level violations of 1,113 Connecticut: 75 systems with lead action-level violations of 504 District of Columbia: 2 systems with lead action-level violations of 12 Delaware: 2 systems with lead action-level violations of 209 Florida: 28 systems with lead action-level violations of 1,516 Georgia: 12 systems with lead action-level violations of 1,718 Hawaii: 2 systems with lead action-level violations of 117 Iowa: 6 systems with lead action-level violations of 1,078 Idaho: 25 systems with lead action-level violations of 774 Illinois: 393 systems with lead action-level violations of 1,785 Indiana: 92 systems with lead action-level violations of 718 Kansas: 102 systems with lead action-level violations of 856 Kentucky: 0 systems with lead action-level violations of 375 Louisiana: 43 systems with lead action-level violations of 819 Massachusetts: 123 systems with lead action-level violations of 559 Maryland: 71 systems with lead action-level violations of 467 Maine: 81 systems with lead action-level violations of 359 Michigan: 81 systems with lead action-level violations of 1,429 Minnesota: 13 systems with lead action-level violations of 995 Missouri: 22 systems with lead action-level violations of 1,679 Mississippi: 6 systems with lead action-level violations of 990 Montana: 38 systems with lead action-level violations of 813 North Carolina: 283 systems with lead action-level violations of 1,963 North Dakota: 30 systems with lead action-level violations of 318 Nebraska: 59 systems with lead action-level violations of 594 New Hampshire: 140 systems with lead action-level violations of 677 New Jersey: 101 systems with lead action-level violations of 620 New Mexico: 2 systems with lead action-level violations of 592 Nevada: 7 systems with lead action-level violations of 232 New York: 103 systems with lead action-level violations of 2,202 Ohio: 74 systems with lead action-level violations of 1,130 Oklahoma: 28 systems with lead action-level violations of 884 Oregon: 127 systems with lead action-level violations of 941 Pennsylvania: 145 systems with lead action-level violations of 1,782 Rhode Island: 20 systems with lead action-level violations of 93 South Carolina: 67 systems with lead action-level violations of 557 South Dakota: 10 systems with lead action-level violations of 513 Tennessee: 11 systems with lead action-level violations of 453 Texas: 230 systems with lead action-level violations of 4,617 Utah: 11 systems with lead action-level violations of 560 Virginia: 62 systems with lead action-level violations of 1,052 Vermont: 50 systems with lead action-level violations of 377 Washington: 27 systems with lead action-level violations of 2,403 Wisconsin: 116 systems with lead action-level violations of 977 West Virginia: 24 systems with lead action-level violations of 430 Wyoming: 14 systems with lead action-level violations of 317
3,177 systems with a lead action-level violation

Maps count public water systems, not people, and reflect reported EPA data — a snapshot, not a live tap measurement. They're best for comparing states, not for judging a single home. Check your exact address for the systems that serve you.